Merge tag 'hid-for-linus-2025032601' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid

Pull HID updates from Jiri Kosina:

- PlayStation 5 controllers support (Alex Henrie)

- big revamp and modernization of the aged hid-pidff force feedback
driver (Tomasz Pakuła)

- conversion of hid-lg-g15 to standard multicolor LED API (Kate Hsuan)

- improvement of behavior of Human Presence Sensor (HPD) in amd_sfh
driver (Mario Limonciello)

- other assorted fixes, code cleanups and device ID additions

* tag 'hid-for-linus-2025032601' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (70 commits)
HID: remove superfluous (and wrong) Makefile entry for CONFIG_INTEL_ISH_FIRMWARE_DOWNLOADER
HID: Intel-thc-hid: Intel-quickspi: Correct device state names gramatically
HID: wacom: Remove static WACOM_PKGLEN_MAX limit
HID: amd_sfh: Don't show wrong status for amd_sfh_hpd_info()
HID: amd_sfh: Default to HPD disabled
HID: amd_sfh: Allow configuring whether HPD is enabled or disabled
HID: pidff: Fix set_device_control()
HID: pidff: Fix 90 degrees direction name North -> East
HID: pidff: Compute INFINITE value instead of using hardcoded 0xffff
HID: pidff: Clamp effect playback LOOP_COUNT value
HID: pidff: Rename two functions to align them with naming convention
HID: lenovo: silence unreachable code warning
HID: lenovo: Fix to ensure the data as __le32 instead of u32
HID: bpf: add a v6.11+ compatible BPF fixup for the XPPen ACK05 remote
HID: bpf: new hid_bpf_async.h common header
HID: bpf: import new kfunc from v6.10 & v6.11
HID: bpf: add support for the XP-Pen Artist Pro 19 (gen2)
HID: bpf: Added updated Kamvas Pro 19 descriptor
HID: bpf: Suppress bogus F13 trigger on Sirius keyboard full fan shortcut
HID: bpf: Add support for the default firmware mode of the Huion K20
...

Documentation/ABI/testing/sysfs-driver-amd-sfh

···
+What:		/sys/bus/pci/drivers/pcie_mp2_amd/*/hpd
+Date:		April 2025
+Contact:	[e-mail]
+Description:
+		Human presence detection (HPD) enable/disable.
+		When HPD is enabled, the device will be able to detect the
+		presence of a human and will send an interrupt that can be
+		used to wake the system from a low power state.
+		When HPD is disabled, the device will not be able to detect
+		the presence of a human.
+
+		Access: Read/Write
+		Valid values: enabled/disabled

Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd

···
+What:		/sys/bus/hid/drivers/hid-appletb-kbd/<dev>/mode
+Date:		September, 2023
+KernelVersion:	6.5
+Contact:	[e-mail]
+Description:
+		The set of keys displayed on the Touch Bar.
+		Valid values are:
+		== =================
+		0  Escape key only
+		1  Function keys
+		2  Media/brightness keys
+		3  None
+		== =================

MAINTAINERS

···
 F:	drivers/iio/*/hid-*
 F:	include/linux/hid-sensor-*
 
+HID UNIVERSAL PIDFF DRIVER
+M:	Tomasz Pakuła <[e-mail]>
+M:	Oleg Makarenko <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+B:	https://github.com/JacKeTUs/universal-pidff/issues
+F:	drivers/hid/hid-universal-pidff.c
+
 HID VRC-2 CAR CONTROLLER DRIVER
 M:	Marcus Folkesson <[e-mail]>
 L:	[e-mail]

drivers/hid/Kconfig

···
 
 	Say Y here if you want support for Apple infrared remote control.
 
+config HID_APPLETB_BL
+	tristate "Apple Touch Bar Backlight"
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want support for the backlight of Touch Bars on x86
+	  MacBook Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-bl.
+
+config HID_APPLETB_KBD
+	tristate "Apple Touch Bar Keyboard Mode"
+	depends on USB_HID
+	depends on BACKLIGHT_CLASS_DEVICE
+	depends on INPUT
+	select INPUT_SPARSEKMAP
+	select HID_APPLETB_BL
+	help
+	  Say Y here if you want support for the keyboard mode (escape,
+	  function, media and brightness keys) of Touch Bars on x86 MacBook
+	  Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-kbd.
+
 config HID_ASUS
 	tristate "Asus"
 	depends on USB_HID
···
 	tristate "Logitech devices"
 	depends on USB_HID
 	depends on LEDS_CLASS
+	depends on LEDS_CLASS_MULTICOLOR
 	default !EXPERT
 	help
 	Support for Logitech devices that are not fully compliant with HID standard.
···
 	  U2F Zero only supports blinking its LED, so this driver doesn't
 	  allow setting the brightness to anything but 1, which will
 	  trigger a single blink and immediately reset back to 0.
+
+config HID_UNIVERSAL_PIDFF
+	tristate "universal-pidff: extended USB PID driver compatibility and usage"
+	depends on USB_HID
+	depends on HID_PID
+	help
+	  Extended PID support for selected devices.
+
+	  Contains report fixups, extended usable button range and
+	  pidff quirk management to extend compatibility with slightly
+	  non-compliant USB PID devices and better fuzz/flat values for
+	  high precision direct drive devices.
+
+	  Supports Moza Racing, Cammus, VRS, FFBeast and more.
 
 config HID_WACOM
 	tristate "Wacom Intuos/Graphire tablet support (USB)"

drivers/hid/Makefile

···
 obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
 obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
 obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
+obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o
+obj-$(CONFIG_HID_APPLETB_KBD)	+= hid-appletb-kbd.o
 obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
 obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
 obj-$(CONFIG_HID_AUREAL)	+= hid-aureal.o
···
 				   hid-uclogic-params.o
 obj-$(CONFIG_HID_UCLOGIC)	+= hid-uclogic.o
 obj-$(CONFIG_HID_UDRAW_PS3)	+= hid-udraw-ps3.o
+obj-$(CONFIG_HID_UNIVERSAL_PIDFF)	+= hid-universal-pidff.o
 obj-$(CONFIG_HID_LED)		+= hid-led.o
 obj-$(CONFIG_HID_XIAOMI)	+= hid-xiaomi.o
 obj-$(CONFIG_HID_XINMO)		+= hid-xinmo.o
···
 obj-$(CONFIG_I2C_HID_CORE)	+= i2c-hid/
 
 obj-$(CONFIG_INTEL_ISH_HID)	+= intel-ish-hid/
-obj-$(INTEL_ISH_FIRMWARE_DOWNLOADER)	+= intel-ish-hid/
 
 obj-$(CONFIG_AMD_SFH_HID)       += amd-sfh-hid/
 

drivers/hid/amd-sfh-hid/amd_sfh_common.h

···
 
 struct sfh_dev_status {
 	bool is_hpd_present;
+	bool is_hpd_enabled;
 	bool is_als_present;
 	bool is_sra_present;
 };

drivers/hid/amd-sfh-hid/amd_sfh_pcie.c

···
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/string_choices.h>
 
 #include "amd_sfh_pcie.h"
 #include "sfh1_1/amd_sfh_init.h"
···
 	{ }
 };
 
+static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct amd_mp2_dev *mp2 = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", str_enabled_disabled(mp2->dev_en.is_hpd_enabled));
+}
+
+static ssize_t hpd_store(struct device *dev,
+			 struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	struct amd_mp2_dev *mp2 = dev_get_drvdata(dev);
+	bool enabled;
+	int ret;
+
+	ret = kstrtobool(buf, &enabled);
+	if (ret)
+		return ret;
+
+	mp2->sfh1_1_ops->toggle_hpd(mp2, enabled);
+
+	return count;
+}
+static DEVICE_ATTR_RW(hpd);
+
+static umode_t sfh_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct amd_mp2_dev *mp2 = dev_get_drvdata(dev);
+
+	if (!mp2->sfh1_1_ops || !mp2->dev_en.is_hpd_present)
+		return 0;
+
+	return attr->mode;
+}
+
+static struct attribute *sfh_attrs[] = {
+	&dev_attr_hpd.attr,
+	NULL,
+};
+
+static struct attribute_group sfh_attr_group = {
+	.attrs = sfh_attrs,
+	.is_visible = sfh_attr_is_visible,
+};
+
+static const struct attribute_group *amd_sfh_groups[] = {
+	&sfh_attr_group,
+	NULL,
+};
+
 static void sfh1_1_init_work(struct work_struct *work)
 {
 	struct amd_mp2_dev *mp2 = container_of(work, struct amd_mp2_dev, work);
···
 
 	amd_sfh_clear_intr(mp2);
 	mp2->init_done = 1;
+
+	rc = sysfs_update_group(&mp2->pdev->dev.kobj, &sfh_attr_group);
+	if (rc)
+		dev_warn(&mp2->pdev->dev, "failed to update sysfs group\n");
+
 }
 
 static void sfh_init_work(struct work_struct *work)
···
 	.driver.pm	= &amd_mp2_pm_ops,
 	.shutdown	= amd_sfh_shutdown,
 	.remove		= amd_sfh_remove,
+	.dev_groups	= amd_sfh_groups,
 };
 module_pci_driver(amd_mp2_pci_driver);
 

drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_init.c

···
 			switch (cl_data->sensor_idx[i]) {
 			case HPD_IDX:
 				privdata->dev_en.is_hpd_present = true;
+				privdata->dev_en.is_hpd_enabled = true;
+				amd_sfh_toggle_hpd(privdata, false);
 				break;
 			case ALS_IDX:
 				privdata->dev_en.is_als_present = true;
···
 	}
 
 	for (i = 0; i < cl_data->num_hid_devices; i++) {
+		/* leave HPD alone; policy is controlled by sysfs */
+		if (cl_data->sensor_idx[i] == HPD_IDX)
+			continue;
+
 		if (cl_data->sensor_sts[i] == SENSOR_DISABLED) {
 			info.sensor_idx = cl_data->sensor_idx[i];
 			mp2->mp2_ops->start(mp2, info);
···
 	}
 
 	for (i = 0; i < cl_data->num_hid_devices; i++) {
-		if (cl_data->sensor_idx[i] != HPD_IDX &&
-		    cl_data->sensor_sts[i] == SENSOR_ENABLED) {
+		/* leave HPD alone; policy is controlled by sysfs */
+		if (cl_data->sensor_idx[i] == HPD_IDX)
+			continue;
+		if (cl_data->sensor_sts[i] == SENSOR_ENABLED) {
 			mp2->mp2_ops->stop(mp2, cl_data->sensor_idx[i]);
 			status = amd_sfh_wait_for_response
 					(mp2, cl_data->sensor_idx[i], DISABLE_SENSOR);
···
 
 	cancel_delayed_work_sync(&cl_data->work_buffer);
 	amd_sfh_clear_intr(mp2);
+}
+
+void amd_sfh_toggle_hpd(struct amd_mp2_dev *mp2, bool enabled)
+{
+	struct amdtp_cl_data *cl_data = mp2->cl_data;
+	struct amd_mp2_sensor_info info;
+	int i, status;
+
+	if (mp2->dev_en.is_hpd_enabled == enabled)
+		return;
+
+	for (i = 0; i < cl_data->num_hid_devices; i++) {
+		if (cl_data->sensor_idx[i] != HPD_IDX)
+			continue;
+		info.sensor_idx = cl_data->sensor_idx[i];
+		if (enabled) {
+			mp2->mp2_ops->start(mp2, info);
+			status = amd_sfh_wait_for_response
+					(mp2, cl_data->sensor_idx[i], ENABLE_SENSOR);
+			if (status == 0)
+				status = SENSOR_ENABLED;
+			if (status == SENSOR_ENABLED)
+				cl_data->sensor_sts[i] = SENSOR_ENABLED;
+		} else {
+			mp2->mp2_ops->stop(mp2, cl_data->sensor_idx[i]);
+			status = amd_sfh_wait_for_response
+					(mp2, cl_data->sensor_idx[i], DISABLE_SENSOR);
+			if (status == 0)
+				status = SENSOR_DISABLED;
+			if (status != SENSOR_ENABLED)
+				cl_data->sensor_sts[i] = SENSOR_DISABLED;
+		}
+		dev_dbg(&mp2->pdev->dev, "toggle sid 0x%x (%s) status 0x%x\n",
+			cl_data->sensor_idx[i], get_sensor_name(cl_data->sensor_idx[i]),
+			cl_data->sensor_sts[i]);
+		break;
+	}
+	mp2->dev_en.is_hpd_enabled = enabled;
 }
 
 static void amd_mp2_pci_remove(void *privdata)

drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_init.h

···
 
 struct amd_sfh1_1_ops {
 	int (*init)(struct amd_mp2_dev *mp2);
+	void (*toggle_hpd)(struct amd_mp2_dev *mp2, bool enable);
 };
 
 int amd_sfh1_1_init(struct amd_mp2_dev *mp2);
+void amd_sfh_toggle_hpd(struct amd_mp2_dev *mp2, bool enabled);
 
 static const struct amd_sfh1_1_ops __maybe_unused sfh1_1_ops = {
 	.init = amd_sfh1_1_init,
+	.toggle_hpd = amd_sfh_toggle_hpd,
 };
 
 #endif

drivers/hid/amd-sfh-hid/sfh1_1/amd_sfh_interface.c

···
 	if (!user_present)
 		return -EINVAL;
 
-	if (!emp2 || !emp2->dev_en.is_hpd_present)
+	if (!emp2 || !emp2->dev_en.is_hpd_present || !emp2->dev_en.is_hpd_enabled)
 		return -ENODEV;
 
 	hpdstatus.val = readl(emp2->mmio + amd_get_c2p_val(emp2, 4));

drivers/hid/bpf/progs/Huion__Kamvas-Pro-19.bpf.c

···
 	0x15, 0x00,                    //   Logical Minimum (0)               22
 	0x25, 0x01,                    //   Logical Maximum (1)               24
 	0x75, 0x01,                    //   Report Size (1)                   26
-	0x95, 0x05,                    //   Report Count (5)                  28 /* changed (was 5) */
+	0x95, 0x05,                    //   Report Count (5)                  28 /* changed (was 6) */
 	0x81, 0x02,                    //   Input (Data,Var,Abs)              30
 	0x05, 0x09,                    //   Usage Page (Button)                  /* inserted */
 	0x09, 0x4a,                    //   Usage (0x4a)                         /* inserted to be translated as input usage 0x149: BTN_STYLUS3 */
···
 	0x96, 0x00, 0x01,              //  Report Count (256)                 322
 	0xb1, 0x02,                    //  Feature (Data,Var,Abs)             325
 	0xc0,                          // End Collection                      327
+	/* New in Firmware Version: HUION_M220_240524 */
+	0x05, 0x01,                    // Usage Page (Generic Desktop)            328
+	0x09, 0x01,                    // Usage (Pointer)                         330
+	0xa1, 0x01,                    // Collection (Application)                332
+	0x09, 0x01,                    //   Usage (Pointer)                       334
+	0xa1, 0x00,                    //   Collection (Physical)                 336
+	0x05, 0x09,                    //     Usage Page (Button)                 338
+	0x19, 0x01,                    //     UsageMinimum (1)                    340
+	0x29, 0x03,                    //     UsageMaximum (3)                    342
+	0x15, 0x00,                    //     Logical Minimum (0)                 344
+	0x25, 0x01,                    //     Logical Maximum (1)                 346
+	0x85, 0x02,                    //     Report ID (2)                       348
+	0x95, 0x03,                    //     Report Count (3)                    350
+	0x75, 0x01,                    //     Report Size (1)                     352
+	0x81, 0x02,                    //     Input (Data,Var,Abs)                354
+	0x95, 0x01,                    //     Report Count (1)                    356
+	0x75, 0x05,                    //     Report Size (5)                     358
+	0x81, 0x01,                    //     Input (Cnst,Arr,Abs)                360
+	0x05, 0x01,                    //     Usage Page (Generic Desktop)        362
+	0x09, 0x30,                    //     Usage (X)                           364
+	0x09, 0x31,                    //     Usage (Y)                           366
+	0x15, 0x81,                    //     Logical Minimum (-127)              368
+	0x25, 0x7f,                    //     Logical Maximum (127)               370
+	0x75, 0x08,                    //     Report Size (8)                     372
+	0x95, 0x02,                    //     Report Count (2)                    374
+	0x81, 0x06,                    //     Input (Data,Var,Rel)                376
+	0x95, 0x04,                    //     Report Count (4)                    378
+	0x75, 0x08,                    //     Report Size (8)                     380
+	0x81, 0x01,                    //     Input (Cnst,Arr,Abs)                382
+	0xc0,                          //   End Collection                        384
+	0xc0,                          // End Collection                          385
+	0x05, 0x0d,                    // Usage Page (Digitizers)                 386
+	0x09, 0x05,                    // Usage (Touch Pad)                       388
+	0xa1, 0x01,                    // Collection (Application)                390
+	0x06, 0x00, 0xff,              //   Usage Page (Vendor Defined Page FF00) 392
+	0x09, 0x0c,                    //   Usage (Vendor Usage 0x0c)             395
+	0x15, 0x00,                    //   Logical Minimum (0)                   397
+	0x26, 0xff, 0x00,              //   Logical Maximum (255)                 399
+	0x75, 0x08,                    //   Report Size (8)                       402
+	0x95, 0x10,                    //   Report Count (16)                     404
+	0x85, 0x3f,                    //   Report ID (63)                        406
+	0x81, 0x22,                    //   Input (Data,Var,Abs,NoPref)           408
+	0xc0,                          // End Collection                          410
+	0x06, 0x00, 0xff,              // Usage Page (Vendor Defined Page FF00)   411
+	0x09, 0x0c,                    // Usage (Vendor Usage 0x0c)               414
+	0xa1, 0x01,                    // Collection (Application)                416
+	0x06, 0x00, 0xff,              //   Usage Page (Vendor Defined Page FF00) 418
+	0x09, 0x0c,                    //   Usage (Vendor Usage 0x0c)             421
+	0x15, 0x00,                    //   Logical Minimum (0)                   423
+	0x26, 0xff, 0x00,              //   Logical Maximum (255)                 425
+	0x85, 0x44,                    //   Report ID (68)                        428
+	0x75, 0x08,                    //   Report Size (8)                       430
+	0x96, 0x6b, 0x05,              //   Report Count (1387)                   432
+	0x81, 0x00,                    //   Input (Data,Arr,Abs)                  435
+	0xc0,                          // End Collection                          437
 };
+
+#define PRE_240524_RDESC_SIZE 328
+#define PRE_240524_RDESC_FIXED_SIZE 338 /* The original bits of the descriptor */
+#define FW_240524_RDESC_SIZE 438
+#define FW_240524_RDESC_FIXED_SIZE sizeof(fixed_rdesc)
 
 SEC(HID_BPF_RDESC_FIXUP)
 int BPF_PROG(hid_fix_rdesc_huion_kamvas_pro_19, struct hid_bpf_ctx *hctx)
···
 	if (!data)
 		return 0; /* EPERM check */
 
-	__builtin_memcpy(data, fixed_rdesc, sizeof(fixed_rdesc));
+	if (hctx->size == FW_240524_RDESC_SIZE) {
+		__builtin_memcpy(data, fixed_rdesc, FW_240524_RDESC_FIXED_SIZE);
+		return sizeof(fixed_rdesc);
+	}
 
-	return sizeof(fixed_rdesc);
+	__builtin_memcpy(data, fixed_rdesc, PRE_240524_RDESC_FIXED_SIZE);
+
+	return PRE_240524_RDESC_FIXED_SIZE;
 }
 
 /*
···
 SEC("syscall")
 int probe(struct hid_bpf_probe_args *ctx)
 {
-	ctx->retval = ctx->rdesc_size != 328;
+
+	ctx->retval = !((ctx->rdesc_size == PRE_240524_RDESC_SIZE) ||
+			(ctx->rdesc_size == FW_240524_RDESC_SIZE));
 	if (ctx->retval)
 		ctx->retval = -EINVAL;
 

drivers/hid/bpf/progs/Huion__KeydialK20.bpf.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2024 Red Hat, Inc
+ */
+
+#include "vmlinux.h"
+#include "hid_bpf.h"
+#include "hid_bpf_helpers.h"
+#include "hid_report_helpers.h"
+#include <bpf/bpf_tracing.h>
+
+#define VID_HUION 0x256C
+#define PID_KEYDIAL_K20 0x0069
+
+HID_BPF_CONFIG(
+	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_HUION, PID_KEYDIAL_K20),
+);
+
+/* Filled in by udev-hid-bpf */
+char UDEV_PROP_HUION_FIRMWARE_ID[64];
+
+/* The prefix of the firmware ID we expect for this device. The full firmware
+ * string has a date suffix, e.g. HUION_T21h_230511
+ */
+char EXPECTED_FIRMWARE_ID[] = "HUION_T21h_";
+
+/* How this BPF program works: the tablet has two modes, firmware mode and
+ * tablet mode. In firmware mode (out of the box) the tablet sends button events
+ * as keyboard shortcuts and the dial as wheel but it's not forwarded by the kernel.
+ * In tablet mode it uses a vendor specific hid report to report everything instead.
+ * Depending on the mode some hid reports are never sent and the corresponding
+ * devices are mute.
+ *
+ * To switch the tablet use e.g.  https://github.com/whot/huion-switcher
+ * or one of the tools from the digimend project
+ *
+ * This BPF currently works for both modes only. The huion-switcher tool sets the
+ * HUION_FIRMWARE_ID udev property - if that is set then we disable the firmware
+ * pad and pen reports (by making them vendor collections that are ignored).
+ * If that property is not set we fix all hidraw nodes so the tablet works in
+ * either mode though the drawback is that the device will show up twice if
+ * you bind it to all event nodes
+ *
+ * Default report descriptor for the first exposed hidraw node:
+ *
+ * # HUION Huion Keydial_K20
+ * # Report descriptor length: 18 bytes
+ * # 0x06, 0x00, 0xff,              // Usage Page (Vendor Defined Page 0xFF00)   0
+ * # 0x09, 0x01,                    // Usage (Vendor Usage 0x01)                 3
+ * # 0xa1, 0x01,                    // Collection (Application)                  5
+ * # 0x85, 0x08,                    //   Report ID (8)                           7
+ * # 0x75, 0x58,                    //   Report Size (88)                        9
+ * # 0x95, 0x01,                    //   Report Count (1)                        11
+ * # 0x09, 0x01,                    //   Usage (Vendor Usage 0x01)               13
+ * # 0x81, 0x02,                    //   Input (Data,Var,Abs)                    15
+ * # 0xc0,                          // End Collection                            17
+ * R: 18 06 00 ff 09 01 a1 01 85 08 75 58 95 01 09 01 81 02 c0
+ *
+ * This report descriptor appears to be identical for all Huion devices.
+ *
+ * Second hidraw node is the Pad. This one sends the button events until the tablet is
+ * switched to raw mode, then it's mute.
+ *
+ * # HUION Huion Keydial_K20
+ * # Report descriptor length: 135 bytes
+ * # 0x05, 0x01,                    // Usage Page (Generic Desktop)              0
+ * # 0x09, 0x06,                    // Usage (Keyboard)                          2
+ * # 0xa1, 0x01,                    // Collection (Application)                  4
+ * # 0x85, 0x03,                    //   Report ID (3)                           6
+ * # 0x05, 0x07,                    //   Usage Page (Keyboard/Keypad)            8
+ * # 0x19, 0xe0,                    //   UsageMinimum (224)                      10
+ * # 0x29, 0xe7,                    //   UsageMaximum (231)                      12
+ * # 0x15, 0x00,                    //   Logical Minimum (0)                     14
+ * # 0x25, 0x01,                    //   Logical Maximum (1)                     16
+ * # 0x75, 0x01,                    //   Report Size (1)                         18
+ * # 0x95, 0x08,                    //   Report Count (8)                        20
+ * # 0x81, 0x02,                    //   Input (Data,Var,Abs)                    22
+ * # 0x05, 0x07,                    //   Usage Page (Keyboard/Keypad)            24
+ * # 0x19, 0x00,                    //   UsageMinimum (0)                        26
+ * # 0x29, 0xff,                    //   UsageMaximum (255)                      28
+ * # 0x26, 0xff, 0x00,              //   Logical Maximum (255)                   30
+ * # 0x75, 0x08,                    //   Report Size (8)                         33
+ * # 0x95, 0x06,                    //   Report Count (6)                        35
+ * # 0x81, 0x00,                    //   Input (Data,Arr,Abs)                    37
+ * # 0xc0,                          // End Collection                            39
+ * # 0x05, 0x0c,                    // Usage Page (Consumer)                     40
+ * # 0x09, 0x01,                    // Usage (Consumer Control)                  42
+ * # 0xa1, 0x01,                    // Collection (Application)                  44
+ * # 0x85, 0x04,                    //   Report ID (4)                           46
+ * # 0x05, 0x0c,                    //   Usage Page (Consumer)                   48
+ * # 0x19, 0x00,                    //   UsageMinimum (0)                        50
+ * # 0x2a, 0x80, 0x03,              //   UsageMaximum (896)                      52
+ * # 0x15, 0x00,                    //   Logical Minimum (0)                     55
+ * # 0x26, 0x80, 0x03,              //   Logical Maximum (896)                   57
+ * # 0x75, 0x10,                    //   Report Size (16)                        60
+ * # 0x95, 0x01,                    //   Report Count (1)                        62
+ * # 0x81, 0x00,                    //   Input (Data,Arr,Abs)                    64
+ * # 0xc0,                          // End Collection                            66
+ * # 0x05, 0x01,                    // Usage Page (Generic Desktop)              67
+ * # 0x09, 0x02,                    // Usage (Mouse)                             69
+ * # 0xa1, 0x01,                    // Collection (Application)                  71
+ * # 0x09, 0x01,                    //   Usage (Pointer)                         73
+ * # 0x85, 0x05,                    //   Report ID (5)                           75
+ * # 0xa1, 0x00,                    //   Collection (Physical)                   77
+ * # 0x05, 0x09,                    //     Usage Page (Button)                   79
+ * # 0x19, 0x01,                    //     UsageMinimum (1)                      81
+ * # 0x29, 0x05,                    //     UsageMaximum (5)                      83
+ * # 0x15, 0x00,                    //     Logical Minimum (0)                   85
+ * # 0x25, 0x01,                    //     Logical Maximum (1)                   87
+ * # 0x95, 0x05,                    //     Report Count (5)                      89
+ * # 0x75, 0x01,                    //     Report Size (1)                       91
+ * # 0x81, 0x02,                    //     Input (Data,Var,Abs)                  93
+ * # 0x95, 0x01,                    //     Report Count (1)                      95
+ * # 0x75, 0x03,                    //     Report Size (3)                       97
+ * # 0x81, 0x01,                    //     Input (Cnst,Arr,Abs)                  99
+ * # 0x05, 0x01,                    //     Usage Page (Generic Desktop)          101
+ * # 0x09, 0x30,                    //     Usage (X)                             103
+ * # 0x09, 0x31,                    //     Usage (Y)                             105
+ * # 0x16, 0x00, 0x80,              //     Logical Minimum (-32768)              107
+ * # 0x26, 0xff, 0x7f,              //     Logical Maximum (32767)               110
+ * # 0x75, 0x10,                    //     Report Size (16)                      113
+ * # 0x95, 0x02,                    //     Report Count (2)                      115
+ * # 0x81, 0x06,                    //     Input (Data,Var,Rel)                  117
+ * # 0x95, 0x01,                    //     Report Count (1)                      119
+ * # 0x75, 0x08,                    //     Report Size (8)                       121
+ * # 0x05, 0x01,                    //     Usage Page (Generic Desktop)          123
+ * # 0x09, 0x38,                    //     Usage (Wheel)                         125
+ * # 0x15, 0x81,                    //     Logical Minimum (-127)                127
+ * # 0x25, 0x7f,                    //     Logical Maximum (127)                 129
+ * # 0x81, 0x06,                    //     Input (Data,Var,Rel)                  131
+ * # 0xc0,                          //   End Collection                          133
+ * # 0xc0,                          // End Collection                            134
+ * R: 135 05 01 09 06 a1 01 85 03 05 07 19 e0 29 e7 15 00 25 01 75 01 95 08 81 02 05 07 19 00 29 ff 26 ff 00 75 08 95 06 81 00 c0 05 0c 09 01 a1 01 85 04 05 0c 19 00 2a 80 03 15 00 26 80 03 75 10 95 01 81 00 c0 05 01 09 02 a1 01 09 01 85 05 a1 00 05 09 19 01 29 05 15 00 25 01 95 05 75 01 81 02 95 01 75 03 81 01 05 01 09 30 09 31 16 00 80 26 ff 7f 7510 95 02 81 06 95 01 75 08 05 01 09 38 15 81 25 7f 81 06 c0 c0
+ *
+ * Third hidraw node is a multi-axis controller which sends the dial events
+ * and the button inside the dial. If the tablet is switched to raw mode it is mute.
+ *
+ * # HUION Huion Keydial_K20
+ * # Report descriptor length: 108 bytes
+ * # 0x05, 0x01,                    // Usage Page (Generic Desktop)              0
+ * # 0x09, 0x0e,                    // Usage (System Multi-Axis Controller)      2
+ * # 0xa1, 0x01,                    // Collection (Application)                  4
+ * # 0x85, 0x11,                    //   Report ID (17)                          6
+ * # 0x05, 0x0d,                    //   Usage Page (Digitizers)                 8
+ * # 0x09, 0x21,                    //   Usage (Puck)                            10
+ * # 0xa1, 0x02,                    //   Collection (Logical)                    12
+ * # 0x15, 0x00,                    //     Logical Minimum (0)                   14
+ * # 0x25, 0x01,                    //     Logical Maximum (1)                   16
+ * # 0x75, 0x01,                    //     Report Size (1)                       18
+ * # 0x95, 0x01,                    //     Report Count (1)                      20
+ * # 0xa1, 0x00,                    //     Collection (Physical)                 22
+ * # 0x05, 0x09,                    //       Usage Page (Button)                 24
+ * # 0x09, 0x01,                    //       Usage (Button 1)                    26
+ * # 0x81, 0x02,                    //       Input (Data,Var,Abs)                28
+ * # 0x05, 0x0d,                    //       Usage Page (Digitizers)             30
+ * # 0x09, 0x33,                    //       Usage (Touch)                       32
+ * # 0x81, 0x02,                    //       Input (Data,Var,Abs)                34
+ * # 0x95, 0x06,                    //       Report Count (6)                    36
+ * # 0x81, 0x03,                    //       Input (Cnst,Var,Abs)                38
+ * # 0xa1, 0x02,                    //       Collection (Logical)                40
+ * # 0x05, 0x01,                    //         Usage Page (Generic Desktop)      42
+ * # 0x09, 0x37,                    //         Usage (Dial)                      44
+ * # 0x16, 0x00, 0x80,              //         Logical Minimum (-32768)          46
+ * # 0x26, 0xff, 0x7f,              //         Logical Maximum (32767)           49
+ * # 0x75, 0x10,                    //         Report Size (16)                  52
+ * # 0x95, 0x01,                    //         Report Count (1)                  54
+ * # 0x81, 0x06,                    //         Input (Data,Var,Rel)              56
+ * # 0x35, 0x00,                    //         Physical Minimum (0)              58
+ * # 0x46, 0x10, 0x0e,              //         Physical Maximum (3600)           60
+ * # 0x15, 0x00,                    //         Logical Minimum (0)               63
+ * # 0x26, 0x10, 0x0e,              //         Logical Maximum (3600)            65
+ * # 0x09, 0x48,                    //         Usage (Resolution Multiplier)     68
+ * # 0xb1, 0x02,                    //         Feature (Data,Var,Abs)            70
+ * # 0x45, 0x00,                    //         Physical Maximum (0)              72
+ * # 0xc0,                          //       End Collection                      74
+ * # 0x75, 0x08,                    //       Report Size (8)                     75
+ * # 0x95, 0x01,                    //       Report Count (1)                    77
+ * # 0x81, 0x01,                    //       Input (Cnst,Arr,Abs)                79
+ * # 0x75, 0x08,                    //       Report Size (8)                     81
+ * # 0x95, 0x01,                    //       Report Count (1)                    83
+ * # 0x81, 0x01,                    //       Input (Cnst,Arr,Abs)                85
+ * # 0x75, 0x08,                    //       Report Size (8)                     87
+ * # 0x95, 0x01,                    //       Report Count (1)                    89
+ * # 0x81, 0x01,                    //       Input (Cnst,Arr,Abs)                91
+ * # 0x75, 0x08,                    //       Report Size (8)                     93
+ * # 0x95, 0x01,                    //       Report Count (1)                    95
+ * # 0x81, 0x01,                    //       Input (Cnst,Arr,Abs)                97
+ * # 0x75, 0x08,                    //       Report Size (8)                     99
+ * # 0x95, 0x01,                    //       Report Count (1)                    101
+ * # 0x81, 0x01,                    //       Input (Cnst,Arr,Abs)                103
+ * # 0xc0,                          //     End Collection                        105
+ * # 0xc0,                          //   End Collection                          106
+ * # 0xc0,                          // End Collection                            107
+ * R: 108 05 01 09 0e a1 01 85 11 05 0d 09 21 a1 02 15 00 25 01 75 01 95 01 a1 00 05 09 09 01 81 02 05 0d 09 33 81 02 95 06 81 03 a1 02 05 01 09 37 16 00 80 26 ff 7f 75 10 95 01 81 06 35 00 46 10 0e 15 00 26 10 0e 09 48 b1 02 45 00 c0 75 08 95 01 81 01 75 08 95 01 81 01 75 08 95 01 81 01 75 08 95 01 81 01 75 08 95 01 81 01 c0 c0 c0
+ *
+ */
+
+#define PAD_REPORT_DESCRIPTOR_LENGTH 135
+#define PUCK_REPORT_DESCRIPTOR_LENGTH 108
+#define VENDOR_REPORT_DESCRIPTOR_LENGTH 18
+#define PAD_KBD_REPORT_ID 3
+#define PAD_CC_REPORT_ID 3  // never sends events
+#define PAD_MOUSE_REPORT_ID 4 // never sends events
+#define PUCK_REPORT_ID 17
+#define VENDOR_REPORT_ID 8
+#define PAD_KBD_REPORT_LENGTH 8
+#define PAD_CC_REPORT_LENGTH 3
+#define PAD_MOUSE_REPORT_LENGTH 7
+#define PUCK_REPORT_LENGTH 9
+#define VENDOR_REPORT_LENGTH 12
+
+__u32 last_button_state;
+
+static const __u8 disabled_rdesc_puck[] = {
+	FixedSizeVendorReport(PUCK_REPORT_LENGTH)
+};
+
+static const __u8 disabled_rdesc_pad[] = {
+	FixedSizeVendorReport(PAD_KBD_REPORT_LENGTH)
+	FixedSizeVendorReport(PAD_CC_REPORT_LENGTH)
+	FixedSizeVendorReport(PAD_MOUSE_REPORT_LENGTH)
+};
+
+static const __u8 fixed_rdesc_vendor[] = {
+	UsagePage_GenericDesktop
+	Usage_GD_Keypad
+	CollectionApplication(
+		// Byte 0
+		// We send our pad events on the vendor report id because why not
+		ReportId(VENDOR_REPORT_ID)
+		UsagePage_Digitizers
+		Usage_Dig_TabletFunctionKeys
+		CollectionPhysical(
+			// Byte 1 is a button so we look like a tablet
+			Usage_Dig_BarrelSwitch	 // BTN_STYLUS, needed so we get to be a tablet pad
+			ReportCount(1)
+			ReportSize(1)
+			Input(Var|Abs)
+			ReportCount(7) // Padding
+			Input(Const)
+			// Bytes 2/3 - x/y just exist so we get to be a tablet pad
+			UsagePage_GenericDesktop
+			Usage_GD_X
+			Usage_GD_Y
+			LogicalMinimum_i8(0x0)
+			LogicalMaximum_i8(0x1)
+			ReportCount(2)
+			ReportSize(8)
+			Input(Var|Abs)
+			// Bytes 4-7 are the button state for 19 buttons + pad out to u32
+			// We send the first 10 buttons as buttons 1-10 which is BTN_0 -> BTN_9
+			UsagePage_Button
+			UsageMinimum_i8(1)
+			UsageMaximum_i8(10)
+			LogicalMinimum_i8(0x0)
+			LogicalMaximum_i8(0x1)
+			ReportCount(10)
+			ReportSize(1)
+			Input(Var|Abs)
+			// We send the other 9 buttons as buttons 0x31 and above -> BTN_A - BTN_TL2
+			UsageMinimum_i8(0x31)
+			UsageMaximum_i8(0x3a)
+			ReportCount(9)
+			ReportSize(1)
+			Input(Var|Abs)
+			ReportCount(13)
+			ReportSize(1)
+			Input(Const) // padding
+			// Byte 6 is the wheel
+			UsagePage_GenericDesktop
+			Usage_GD_Wheel
+			LogicalMinimum_i8(-1)
+			LogicalMaximum_i8(1)
+			ReportCount(1)
+			ReportSize(8)
+			Input(Var|Rel)
+		)
+		// Make sure we match our original report length
+		FixedSizeVendorReport(VENDOR_REPORT_LENGTH)
+	)
+};
+
+/* Identical to fixed_rdesc_pad but with different FixedSizeVendorReport */
+static const __u8 fixed_rdesc_pad[] = {
+	UsagePage_GenericDesktop
+	Usage_GD_Keypad
+	CollectionApplication(
+		// Byte 0
+		// We send our pad events on the vendor report id because why not
+		ReportId(VENDOR_REPORT_ID)
+		UsagePage_Digitizers
+		Usage_Dig_TabletFunctionKeys
+		CollectionPhysical(
+			// Byte 1 is a button so we look like a tablet
+			Usage_Dig_BarrelSwitch	 // BTN_STYLUS, needed so we get to be a tablet pad
+			ReportCount(1)
+			ReportSize(1)
+			Input(Var|Abs)
+			ReportCount(7) // Padding
+			Input(Const)
+			// Bytes 2/3 - x/y just exist so we get to be a tablet pad
+			UsagePage_GenericDesktop
+			Usage_GD_X
+			Usage_GD_Y
+			LogicalMinimum_i8(0x0)
+			LogicalMaximum_i8(0x1)
+			ReportCount(2)
+			ReportSize(8)
+			Input(Var|Abs)
+			// Bytes 4-7 are the button state for 19 buttons + pad out to u32
+			// We send the first 10 buttons as buttons 1-10 which is BTN_0 -> BTN_9
+			UsagePage_Button
+			UsageMinimum_i8(1)
+			UsageMaximum_i8(10)
+			LogicalMinimum_i8(0x0)
+			LogicalMaximum_i8(0x1)
+			ReportCount(10)
+			ReportSize(1)
+			Input(Var|Abs)
+			// We send the other 9 buttons as buttons 0x31 and above -> BTN_A - BTN_TL2
+			UsageMinimum_i8(0x31)
+			UsageMaximum_i8(0x3a)
+			ReportCount(9)
+			ReportSize(1)
+			Input(Var|Abs)
+			ReportCount(13)
+			ReportSize(1)
+			Input(Const) // padding
+			// Byte 6 is the wheel
+			UsagePage_GenericDesktop
+			Usage_GD_Wheel
+			LogicalMinimum_i8(-1)
+			LogicalMaximum_i8(1)
+			ReportCount(1)
+			ReportSize(8)
+			Input(Var|Rel)
+		)
+		// Make sure we match our original report lengths
+		FixedSizeVendorReport(PAD_KBD_REPORT_LENGTH)
+		FixedSizeVendorReport(PAD_CC_REPORT_LENGTH)
+		FixedSizeVendorReport(PAD_MOUSE_REPORT_LENGTH)
+	)
+};
+
+SEC(HID_BPF_RDESC_FIXUP)
+int BPF_PROG(k20_fix_rdesc, struct hid_bpf_ctx *hctx)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, HID_MAX_DESCRIPTOR_SIZE /* size */);
+	__s32 rdesc_size = hctx->size;
+	__u8 have_fw_id;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* If we have a firmware ID and it matches our expected prefix, we
+	 * disable the default pad/puck nodes. They won't send events
+	 * but cause duplicate devices.
+	 */
+	have_fw_id = __builtin_memcmp(UDEV_PROP_HUION_FIRMWARE_ID,
+				      EXPECTED_FIRMWARE_ID,
+				      sizeof(EXPECTED_FIRMWARE_ID) - 1) == 0;
+	if (rdesc_size == PAD_REPORT_DESCRIPTOR_LENGTH) {
+		if (have_fw_id) {
+			__builtin_memcpy(data, disabled_rdesc_pad, sizeof(disabled_rdesc_pad));
+			return sizeof(disabled_rdesc_pad);
+		} else {
+			__builtin_memcpy(data, fixed_rdesc_pad, sizeof(fixed_rdesc_pad));
+			return sizeof(fixed_rdesc_pad);
+
+		}
+	}
+	if (rdesc_size == PUCK_REPORT_DESCRIPTOR_LENGTH) {
+		if (have_fw_id) {
+			__builtin_memcpy(data, disabled_rdesc_puck, sizeof(disabled_rdesc_puck));
+			return sizeof(disabled_rdesc_puck);
+		}
+	}
+	/* Always fix the vendor mode so the tablet will work even if nothing sets
+	 * the udev property (e.g. huion-switcher run manually)
+	 */
+	if (rdesc_size == VENDOR_REPORT_DESCRIPTOR_LENGTH) {
+		__builtin_memcpy(data, fixed_rdesc_vendor, sizeof(fixed_rdesc_vendor));
+		return sizeof(fixed_rdesc_vendor);
+
+	}
+	return 0;
+}
+
+SEC(HID_BPF_DEVICE_EVENT)
+int BPF_PROG(k20_fix_events, struct hid_bpf_ctx *hctx)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 10 /* size */);
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* Only sent if tablet is in raw mode */
+	if (data[0] == VENDOR_REPORT_ID) {
+		/* See fixed_rdesc_pad */
+		struct pad_report {
+			__u8 report_id;
+			__u8 btn_stylus:1;
+			__u8 pad:7;
+			__u8 x;
+			__u8 y;
+			__u32 buttons;
+			__u8 wheel;
+		} __attribute__((packed)) *pad_report;
+
+		__u8 wheel = 0;
+
+		/* Wheel report */
+		if (data[1] == 0xf1) {
+			if (data[5] == 2)
+				wheel = 0xff;
+			else
+				wheel = data[5];
+		} else {
+			/* data[4..6] are the buttons, mapped correctly */
+			last_button_state = data[4] | (data[5] << 8) | (data[6] << 16);
+			wheel = 0; // wheel
+		}
+
+		pad_report = (struct pad_report *)data;
+		pad_report->report_id = VENDOR_REPORT_ID;
+		pad_report->btn_stylus = 0;
+		pad_report->x = 0;
+		pad_report->y = 0;
+		pad_report->buttons = last_button_state;
+		pad_report->wheel = wheel;
+
+		return sizeof(struct pad_report);
+	}
+
+	if (data[0] == PAD_KBD_REPORT_ID) {
+		const __u8 button_mapping[] = {
+			0x0e, /* Button 1:  K */
+			0x0a, /* Button 2:  G */
+			0x0f, /* Button 3:  L */
+			0x4c, /* Button 4:  Delete */
+			0x0c, /* Button 5:  I */
+			0x07, /* Button 6:  D */
+			0x05, /* Button 7:  B */
+			0x08, /* Button 8:  E */
+			0x16, /* Button 9:  S */
+			0x1d, /* Button 10: Z */
+			0x06, /* Button 11: C */
+			0x19, /* Button 12: V */
+			0xff, /* Button 13: LeftControl */
+			0xff, /* Button 14: LeftAlt */
+			0xff, /* Button 15: LeftShift */
+			0x28, /* Button 16: Return Enter */
+			0x2c, /* Button 17: Spacebar */
+			0x11, /* Button 18: N */
+		};
+		/* See fixed_rdesc_pad */
+		struct pad_report {
+			__u8 report_id;
+			__u8 btn_stylus:1;
+			__u8 pad:7;
+			__u8 x;
+			__u8 y;
+			__u32 buttons;
+			__u8 wheel;
+		} __attribute__((packed)) *pad_report;
+		int i, b;
+		__u8 modifiers = data[1];
+		__u32 buttons = 0;
+
+		if (modifiers & 0x01) { /* Control */
+			buttons |= BIT(12);
+		}
+		if (modifiers & 0x02) { /* Shift */
+			buttons |= BIT(14);
+		}
+		if (modifiers & 0x04) { /* Alt */
+			buttons |= BIT(13);
+		}
+
+		for (i = 2; i < PAD_KBD_REPORT_LENGTH; i++) {
+			if (!data[i])
+				break;
+
+			for (b = 0; b < ARRAY_SIZE(button_mapping); b++) {
+				if (data[i] == button_mapping[b]) {
+					buttons |= BIT(b);
+					break;
+				}
+			}
+			data[i] = 0;
+		}
+
+		pad_report = (struct pad_report *)data;
+		pad_report->report_id = VENDOR_REPORT_ID;
+		pad_report->btn_stylus = 0;
+		pad_report->x = 0;
+		pad_report->y = 0;
+		pad_report->buttons = buttons;
+		// The wheel happens on a different hidraw node but its
+		// values are unreliable (as is the button inside the wheel).
+		// So the wheel is simply always zero, if you want the wheel
+		// to work reliably, use the tablet mode.
+		pad_report->wheel = 0;
+
+		return sizeof(struct pad_report);
+	}
+
+	return 0;
+}
+
+HID_BPF_OPS(keydial_k20) = {
+	.hid_device_event = (void *)k20_fix_events,
+	.hid_rdesc_fixup = (void *)k20_fix_rdesc,
+};
+
+SEC("syscall")
+int probe(struct hid_bpf_probe_args *ctx)
+{
+	switch (ctx->rdesc_size) {
+	case PAD_REPORT_DESCRIPTOR_LENGTH:
+	case PUCK_REPORT_DESCRIPTOR_LENGTH:
+	case VENDOR_REPORT_DESCRIPTOR_LENGTH:
+		ctx->retval = 0;
+		break;
+	default:
+		ctx->retval = -EINVAL;
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";

drivers/hid/bpf/progs/TUXEDO__Sirius-16-Gen1-and-Gen2.bpf.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright (c) 2025 TUXEDO Computers GmbH
+ */
+
+#include "vmlinux.h"
+#include "hid_bpf.h"
+#include "hid_bpf_helpers.h"
+#include <bpf/bpf_tracing.h>
+
+HID_BPF_CONFIG(
+	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 0x048D, 0x8910)
+);
+
+SEC(HID_BPF_DEVICE_EVENT)
+int BPF_PROG(ignore_key_fix_event, struct hid_bpf_ctx *hid_ctx)
+{
+	const int expected_length = 37;
+	const int expected_report_id = 1;
+	__u8 *data;
+	int i;
+
+	if (hid_ctx->size < expected_length)
+		return 0;
+
+	data = hid_bpf_get_data(hid_ctx, 0, expected_length);
+	if (!data || data[0] != expected_report_id)
+		return 0;
+
+	// Zero out F13 (HID usage ID: 0x68) key press.
+	// The first 6 parallel key presses (excluding modifier keys) are
+	// encoded in an array containing usage IDs.
+	for (i = 3; i < 9; ++i)
+		if (data[i] == 0x68)
+			data[i] = 0x00;
+	// Additional parallel key presses starting with the 7th (excluding
+	// modifier keys) are encoded as a bit flag with the offset being
+	// the usage ID.
+	data[22] &= 0xfe;
+
+	return 0;
+}
+
+HID_BPF_OPS(ignore_button) = {
+	.hid_device_event = (void *)ignore_key_fix_event,
+};
+
+char _license[] SEC("license") = "GPL";

drivers/hid/bpf/progs/XPPen__ACK05.bpf.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2024 Red Hat, Inc
+ */
+
+#include "vmlinux.h"
+#include "hid_bpf.h"
+#include "hid_bpf_helpers.h"
+#include "hid_report_helpers.h"
+#include <bpf/bpf_tracing.h>
+
+#define HID_BPF_ASYNC_MAX_CTX 1
+#include "hid_bpf_async.h"
+
+#define VID_UGEE		0x28BD
+/* same PID whether connected directly or through the provided dongle: */
+#define PID_ACK05_REMOTE	0x0202
+
+
+HID_BPF_CONFIG(
+	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ACK05_REMOTE),
+);
+
+/*
+ * By default, the pad reports the buttons through a set of key sequences.
+ *
+ * The pad reports a classic keyboard report descriptor:
+ * # HANVON UGEE Shortcut Remote
+ * Report descriptor length: 102 bytes
+ *  0x05, 0x01,                    // Usage Page (Generic Desktop)              0
+ *  0x09, 0x02,                    // Usage (Mouse)                             2
+ *  0xa1, 0x01,                    // Collection (Application)                  4
+ *  0x85, 0x09,                    //   Report ID (9)                           6
+ *  0x09, 0x01,                    //   Usage (Pointer)                         8
+ *  0xa1, 0x00,                    //   Collection (Physical)                   10
+ *  0x05, 0x09,                    //     Usage Page (Button)                   12
+ *  0x19, 0x01,                    //     UsageMinimum (1)                      14
+ *  0x29, 0x03,                    //     UsageMaximum (3)                      16
+ *  0x15, 0x00,                    //     Logical Minimum (0)                   18
+ *  0x25, 0x01,                    //     Logical Maximum (1)                   20
+ *  0x95, 0x03,                    //     Report Count (3)                      22
+ *  0x75, 0x01,                    //     Report Size (1)                       24
+ *  0x81, 0x02,                    //     Input (Data,Var,Abs)                  26
+ *  0x95, 0x05,                    //     Report Count (5)                      28
+ *  0x81, 0x01,                    //     Input (Cnst,Arr,Abs)                  30
+ *  0x05, 0x01,                    //     Usage Page (Generic Desktop)          32
+ *  0x09, 0x30,                    //     Usage (X)                             34
+ *  0x09, 0x31,                    //     Usage (Y)                             36
+ *  0x26, 0xff, 0x7f,              //     Logical Maximum (32767)               38
+ *  0x95, 0x02,                    //     Report Count (2)                      41
+ *  0x75, 0x10,                    //     Report Size (16)                      43
+ *  0x81, 0x02,                    //     Input (Data,Var,Abs)                  45
+ *  0x05, 0x0d,                    //     Usage Page (Digitizers)               47
+ *  0x09, 0x30,                    //     Usage (Tip Pressure)                  49
+ *  0x26, 0xff, 0x07,              //     Logical Maximum (2047)                51
+ *  0x95, 0x01,                    //     Report Count (1)                      54
+ *  0x75, 0x10,                    //     Report Size (16)                      56
+ *  0x81, 0x02,                    //     Input (Data,Var,Abs)                  58
+ *  0xc0,                          //   End Collection                          60
+ *  0xc0,                          // End Collection                            61
+ *  0x05, 0x01,                    // Usage Page (Generic Desktop)              62
+ *  0x09, 0x06,                    // Usage (Keyboard)                          64
+ *  0xa1, 0x01,                    // Collection (Application)                  66
+ *  0x85, 0x06,                    //   Report ID (6)                           68
+ *  0x05, 0x07,                    //   Usage Page (Keyboard/Keypad)            70
+ *  0x19, 0xe0,                    //   UsageMinimum (224)                      72
+ *  0x29, 0xe7,                    //   UsageMaximum (231)                      74
+ *  0x15, 0x00,                    //   Logical Minimum (0)                     76
+ *  0x25, 0x01,                    //   Logical Maximum (1)                     78
+ *  0x75, 0x01,                    //   Report Size (1)                         80
+ *  0x95, 0x08,                    //   Report Count (8)                        82
+ *  0x81, 0x02,                    //   Input (Data,Var,Abs)                    84
+ *  0x05, 0x07,                    //   Usage Page (Keyboard/Keypad)            86
+ *  0x19, 0x00,                    //   UsageMinimum (0)                        88
+ *  0x29, 0xff,                    //   UsageMaximum (255)                      90
+ *  0x26, 0xff, 0x00,              //   Logical Maximum (255)                   92
+ *  0x75, 0x08,                    //   Report Size (8)                         95
+ *  0x95, 0x06,                    //   Report Count (6)                        97
+ *  0x81, 0x00,                    //   Input (Data,Arr,Abs)                    99
+ *  0xc0,                          // End Collection                            101
+ *
+ * Each button gets assigned the following events:
+ *
+ *   Buttons released: 06 00 00 00 00 00 00 00
+ *   Button 1:         06 01 12 00 00 00 00 00 -> LControl + o
+ *   Button 2:         06 01 11 00 00 00 00 00 -> LControl + n
+ *   Button 3:         06 00 3e 00 00 00 00 00 -> F5
+ *   Button 4:         06 02 00 00 00 00 00 00 -> LShift
+ *   Button 5:         06 01 00 00 00 00 00 00 -> LControl
+ *   Button 6:         06 04 00 00 00 00 00 00 -> LAlt
+ *   Button 7:         06 01 16 00 00 00 00 00 -> LControl + s
+ *   Button 8:         06 01 1d 00 00 00 00 00 -> LControl + z
+ *   Button 9:         06 00 2c 00 00 00 00 00 -> Space
+ *   Button 10:        06 03 1d 00 00 00 00 00 -> LControl + LShift + z
+ *   Wheel:            06 01 57 00 00 00 00 00 -> clockwise rotation (LControl + Keypad Plus)
+ *   Wheel:            06 01 56 00 00 00 00 00 -> counter-clockwise rotation
+ *						  (LControl + Keypad Minus)
+ *
+ * However, multiple buttons can be pressed at the same time, and when this happens,
+ * each button gets assigned a new slot in the Input (Data,Arr,Abs):
+ *
+ *   Button 1 + 3:     06 01 12 3e 00 00 00 00 -> LControl + o + F5
+ *
+ * When a modifier is pressed (Button 4, 5, or 6), the assigned key is set to 00:
+ *
+ *   Button 5 + 7:     06 01 00 16 00 00 00 00 -> LControl + s
+ *
+ * This is mostly fine, but with Button 8 and Button 10 sharing the same
+ * key value ("z"), there are cases where we can not know which is which.
+ *
+ */
+
+#define PAD_WIRED_DESCRIPTOR_LENGTH 102
+#define PAD_DONGLE_DESCRIPTOR_LENGTH 177
+#define STYLUS_DESCRIPTOR_LENGTH 109
+#define VENDOR_DESCRIPTOR_LENGTH 36
+#define PAD_REPORT_ID 6
+#define RAW_PAD_REPORT_ID 0xf0
+#define RAW_BATTERY_REPORT_ID 0xf2
+#define VENDOR_REPORT_ID 2
+#define PAD_REPORT_LENGTH 8
+#define VENDOR_REPORT_LENGTH 12
+
+__u16 last_button_state;
+
+static const __u8 disabled_rdesc[] = {
+	// Make sure we match our original report length
+	FixedSizeVendorReport(VENDOR_REPORT_LENGTH)
+};
+
+static const __u8 fixed_rdesc_vendor[] = {
+	UsagePage_GenericDesktop
+	Usage_GD_Keypad
+	CollectionApplication(
+		// -- Byte 0 in report
+		ReportId(RAW_PAD_REPORT_ID)
+		// Byte 1 in report - same than report ID
+		ReportCount(1)
+		ReportSize(8)
+		Input(Const) // padding (internal report ID)
+		LogicalMaximum_i8(0)
+		LogicalMaximum_i8(1)
+		UsagePage_Digitizers
+		Usage_Dig_TabletFunctionKeys
+		CollectionPhysical(
+			// Byte 2-3 is the button state
+			UsagePage_Button
+			UsageMinimum_i8(0x01)
+			UsageMaximum_i8(0x0a)
+			LogicalMinimum_i8(0x0)
+			LogicalMaximum_i8(0x1)
+			ReportCount(10)
+			ReportSize(1)
+			Input(Var|Abs)
+			Usage_i8(0x31) // will be mapped as BTN_A / BTN_SOUTH
+			ReportCount(1)
+			Input(Var|Abs)
+			ReportCount(5) // padding
+			Input(Const)
+			// Byte 4 in report - just exists so we get to be a tablet pad
+			Usage_Dig_BarrelSwitch // BTN_STYLUS
+			ReportCount(1)
+			ReportSize(1)
+			Input(Var|Abs)
+			ReportCount(7) // padding
+			Input(Const)
+			// Bytes 5/6 in report - just exists so we get to be a tablet pad
+			UsagePage_GenericDesktop
+			Usage_GD_X
+			Usage_GD_Y
+			ReportCount(2)
+			ReportSize(8)
+			Input(Var|Abs)
+			// Byte 7 in report is the dial
+			Usage_GD_Wheel
+			LogicalMinimum_i8(-1)
+			LogicalMaximum_i8(1)
+			ReportCount(1)
+			ReportSize(8)
+			Input(Var|Rel)
+		)
+		// -- Byte 0 in report
+		ReportId(RAW_BATTERY_REPORT_ID)
+		// Byte 1 in report - same than report ID
+		ReportCount(1)
+		ReportSize(8)
+		Input(Const) // padding (internal report ID)
+		// Byte 2 in report - always 0x01
+		Input(Const) // padding (internal report ID)
+		UsagePage_Digitizers
+		/*
+		 * We represent the device as a stylus to force the kernel to not
+		 * directly query its battery state. Instead the kernel will rely
+		 * only on the provided events.
+		 */
+		Usage_Dig_Stylus
+		CollectionPhysical(
+			// Byte 3 in report - battery value
+			UsagePage_BatterySystem
+			Usage_BS_AbsoluteStateOfCharge
+			LogicalMinimum_i8(0)
+			LogicalMaximum_i8(100)
+			ReportCount(1)
+			ReportSize(8)
+			Input(Var|Abs)
+			// Byte 4 in report - charging state
+			Usage_BS_Charging
+			LogicalMinimum_i8(0)
+			LogicalMaximum_i8(1)
+			ReportCount(1)
+			ReportSize(8)
+			Input(Var|Abs)
+		)
+	)
+};
+
+SEC(HID_BPF_RDESC_FIXUP)
+int BPF_PROG(ack05_fix_rdesc, struct hid_bpf_ctx *hctx)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, HID_MAX_DESCRIPTOR_SIZE /* size */);
+	__s32 rdesc_size = hctx->size;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	if (rdesc_size == VENDOR_DESCRIPTOR_LENGTH) {
+		/*
+		 * The vendor fixed rdesc is appended after the current one,
+		 * to keep the output reports working.
+		 */
+		__builtin_memcpy(data + rdesc_size, fixed_rdesc_vendor, sizeof(fixed_rdesc_vendor));
+		return sizeof(fixed_rdesc_vendor) + rdesc_size;
+	}
+
+	hid_set_name(hctx->hid, "Disabled by HID-BPF Hanvon Ugee Shortcut Remote");
+
+	__builtin_memcpy(data, disabled_rdesc, sizeof(disabled_rdesc));
+	return sizeof(disabled_rdesc);
+}
+
+static int HID_BPF_ASYNC_FUN(switch_to_raw_mode)(struct hid_bpf_ctx *hid)
+{
+	static __u8 magic_0[32] = {0x02, 0xb0, 0x04, 0x00, 0x00};
+	int err;
+
+	/*
+	 * The proprietary driver sends the 3 following packets after the
+	 * above one.
+	 * These don't seem to have any effect, so we don't send them to save
+	 * some processing time.
+	 *
+	 * static __u8 magic_1[32] = {0x02, 0xb4, 0x01, 0x00, 0x01};
+	 * static __u8 magic_2[32] = {0x02, 0xb4, 0x01, 0x00, 0xff};
+	 * static __u8 magic_3[32] = {0x02, 0xb8, 0x04, 0x00, 0x00};
+	 */
+
+	err = hid_bpf_hw_output_report(hid, magic_0, sizeof(magic_0));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+SEC(HID_BPF_DEVICE_EVENT)
+int BPF_PROG(ack05_fix_events, struct hid_bpf_ctx *hctx)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, PAD_REPORT_LENGTH);
+	int ret = 0;
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	if (data[0] != VENDOR_REPORT_ID)
+		return 0;
+
+	/* reconnect event */
+	if (data[1] == 0xf8 && data[2] == 02 && data[3] == 0x01)
+		HID_BPF_ASYNC_DELAYED_CALL(switch_to_raw_mode, hctx, 10);
+
+	/* button event */
+	if (data[1] == RAW_PAD_REPORT_ID) {
+		data[0] = data[1];
+		if (data[7] == 0x02)
+			data[7] = 0xff;
+		ret = 8;
+	} else if (data[1] == RAW_BATTERY_REPORT_ID) {
+		data[0] = data[1];
+		ret = 5;
+	}
+
+	return ret;
+}
+
+HID_BPF_OPS(xppen_ack05_remote) = {
+	.hid_device_event = (void *)ack05_fix_events,
+	.hid_rdesc_fixup = (void *)ack05_fix_rdesc,
+};
+
+SEC("syscall")
+int probe(struct hid_bpf_probe_args *ctx)
+{
+	switch (ctx->rdesc_size) {
+	case PAD_WIRED_DESCRIPTOR_LENGTH:
+	case PAD_DONGLE_DESCRIPTOR_LENGTH:
+	case STYLUS_DESCRIPTOR_LENGTH:
+	case VENDOR_DESCRIPTOR_LENGTH:
+		ctx->retval = 0;
+		break;
+	default:
+		ctx->retval = -EINVAL;
+		break;
+	}
+
+	if (ctx->rdesc_size == VENDOR_DESCRIPTOR_LENGTH) {
+		struct hid_bpf_ctx *hctx = hid_bpf_allocate_context(ctx->hid);
+
+		if (!hctx) {
+			ctx->retval = -EINVAL;
+			return 0;
+		}
+
+		ctx->retval = HID_BPF_ASYNC_INIT(switch_to_raw_mode) ||
+			      switch_to_raw_mode(hctx);
+
+		hid_bpf_release_context(hctx);
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";

drivers/hid/bpf/progs/XPPen__ArtistPro16Gen2.bpf.c

···
 #define VID_UGEE 0x28BD /* VID is shared with SinoWealth and Glorious and prob others */
 #define PID_ARTIST_PRO14_GEN2 0x095A
 #define PID_ARTIST_PRO16_GEN2 0x095B
+#define PID_ARTIST_PRO19_GEN2 0x096A
 
 HID_BPF_CONFIG(
 	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ARTIST_PRO14_GEN2),
-	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ARTIST_PRO16_GEN2)
+	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ARTIST_PRO16_GEN2),
+	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_UGEE, PID_ARTIST_PRO19_GEN2)
 );
 
 /*
···
  * - when the eraser button is pressed and the stylus is touching the tablet,
  *   the device sends Tip Switch instead of sending Eraser
  *
- * This descriptor uses physical dimensions of the 16" device.
+ * This descriptor uses the physical dimensions of the 16" device.
  */
 static const __u8 fixed_rdesc[] = {
 	0x05, 0x0d,                    // Usage Page (Digitizers)             0
···
 		data[62] = 0x62;
 		data[73] = 0x1c;
 		data[72] = 0xfd;
+	} else if (hctx->hid->product == PID_ARTIST_PRO19_GEN2) {
+		/* 19" screen reports 16.101" x 9.057" */
+		data[63] = 0x3e;
+		data[62] = 0xe5;
+		data[73] = 0x23;
+		data[72] = 0x61;
 	}
 
 	return sizeof(fixed_rdesc);
···
 	188, 186, 184, 182, 180, 178, 176, 174, 172
 };
 
+/* 19" inch screen 16.101" x 9.057" */
+static const __u16 angle_offsets_horizontal_19[128] = {
+	0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 25, 27, 29, 31, 33, 35, 37, 39, 41,
+	42, 44, 46, 48, 50, 51, 53, 55, 57, 58, 60, 62, 63, 65, 67, 68, 70, 71, 73, 74, 76,
+	77, 79, 80, 82, 83, 84, 86, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97, 98, 99, 100,
+	101, 102, 103, 104, 104, 105, 106, 106, 107, 108, 108, 109, 109, 110, 110, 111,
+	111, 112, 112, 112, 112, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113, 113,
+	113, 113, 112, 112, 112, 112, 111, 111, 110, 110, 109, 109, 108, 108, 107, 106,
+	106, 105, 104, 104, 103, 102, 101, 100, 99, 98, 97, 96, 95, 94, 93, 92, 90
+};
+static const __u16 angle_offsets_vertical_19[128] = {
+	0, 4, 7, 11, 14, 18, 21, 25, 28, 32, 35, 38, 42, 45, 49, 52, 56, 59, 62, 66, 69, 72,
+	75, 79, 82, 85, 88, 91, 95, 98, 101, 104, 107, 110, 113, 116, 118, 121, 124, 127,
+	129, 132, 135, 137, 140, 142, 145, 147, 150, 152, 154, 157, 159, 161, 163, 165, 167,
+	169, 171, 173, 174, 176, 178, 179, 181, 183, 184, 185, 187, 188, 189, 190, 192, 193,
+	194, 195, 195, 196, 197, 198, 198, 199, 199, 200, 200, 201, 201, 201, 201, 201, 201,
+	201, 201, 201, 201, 201, 200, 200, 199, 199, 198, 198, 197, 196, 195, 195, 194, 193,
+	192, 190, 189, 188, 187, 185, 184, 183, 181, 179, 178, 176, 174, 173, 171, 169, 167,
+	165, 163, 161
+};
+
 static void compensate_coordinates_by_tilt(__u8 *data, const __u8 idx,
 		const __s8 tilt, const __u16 (*compensation_table)[128])
 {
···
 	__s8 tilt_x = (__s8) data[8];
 	__s8 tilt_y = (__s8) data[9];
 
-	if (hctx->hid->product == PID_ARTIST_PRO14_GEN2) {
+	switch (hctx->hid->product) {
+	case PID_ARTIST_PRO14_GEN2:
 		compensate_coordinates_by_tilt(data, 2, tilt_x, &angle_offsets_horizontal_14);
 		compensate_coordinates_by_tilt(data, 4, tilt_y, &angle_offsets_vertical_14);
-	} else if (hctx->hid->product == PID_ARTIST_PRO16_GEN2) {
+		break;
+	case PID_ARTIST_PRO16_GEN2:
 		compensate_coordinates_by_tilt(data, 2, tilt_x, &angle_offsets_horizontal_16);
 		compensate_coordinates_by_tilt(data, 4, tilt_y, &angle_offsets_vertical_16);
+		break;
+	case PID_ARTIST_PRO19_GEN2:
+		compensate_coordinates_by_tilt(data, 2, tilt_x, &angle_offsets_horizontal_19);
+		compensate_coordinates_by_tilt(data, 4, tilt_y, &angle_offsets_vertical_19);
+		break;
 	}
 
 	return 0;

drivers/hid/bpf/progs/hid_bpf_async.h

···
+/* SPDX-License-Identifier: GPL-2.0-only
+ * Copyright (c) 2024 Benjamin Tissoires
+ */
+
+#ifndef __HID_BPF_ASYNC_H__
+#define __HID_BPF_ASYNC_H__
+
+#ifndef HID_BPF_ASYNC_MAX_CTX
+#error "HID_BPF_ASYNC_MAX_CTX should be set to the maximum number of concurrent async functions"
+#endif /* HID_BPF_ASYNC_MAX_CTX */
+
+#define CLOCK_MONOTONIC		1
+
+typedef int (*hid_bpf_async_callback_t)(void *map, int *key, void *value);
+
+enum hid_bpf_async_state {
+	HID_BPF_ASYNC_STATE_UNSET = 0,
+	HID_BPF_ASYNC_STATE_INITIALIZING,
+	HID_BPF_ASYNC_STATE_INITIALIZED,
+	HID_BPF_ASYNC_STATE_STARTING,
+	HID_BPF_ASYNC_STATE_RUNNING,
+};
+
+struct hid_bpf_async_map_elem {
+	struct bpf_spin_lock lock;
+	enum hid_bpf_async_state state;
+	struct bpf_timer t;
+	struct bpf_wq wq;
+	u32 hid;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, HID_BPF_ASYNC_MAX_CTX);
+	__type(key, u32);
+	__type(value, struct hid_bpf_async_map_elem);
+} hid_bpf_async_ctx_map SEC(".maps");
+
+/**
+ * HID_BPF_ASYNC_CB: macro to define an async callback used in a bpf_wq
+ *
+ * The caller is responsible for allocating a key in the async map
+ * with hid_bpf_async_get_ctx().
+ */
+#define HID_BPF_ASYNC_CB(cb)					\
+cb(void *map, int *key, void *value);				\
+static __always_inline int					\
+____##cb(struct hid_bpf_ctx *ctx);				\
+typeof(cb(0, 0, 0)) cb(void *map, int *key, void *value)	\
+{								\
+	struct hid_bpf_async_map_elem *e;				\
+	struct hid_bpf_ctx *ctx;				\
+								\
+	e = (struct hid_bpf_async_map_elem *)value;			\
+	ctx = hid_bpf_allocate_context(e->hid);			\
+	if (!ctx)						\
+		return 0; /* EPERM check */			\
+								\
+	e->state = HID_BPF_ASYNC_STATE_RUNNING;			\
+								\
+	____##cb(ctx);						\
+								\
+	e->state = HID_BPF_ASYNC_STATE_INITIALIZED;		\
+	hid_bpf_release_context(ctx);				\
+	return 0;						\
+}								\
+static __always_inline int					\
+____##cb
+
+/**
+ * ASYNC: macro to automatically handle async callbacks contexts
+ *
+ * Needs to be used in conjunction with HID_BPF_ASYNC_INIT and HID_BPF_ASYNC_DELAYED_CALL
+ */
+#define HID_BPF_ASYNC_FUN(fun)						\
+fun(struct hid_bpf_ctx *ctx);					\
+int ____key__##fun;						\
+static int ____async_init_##fun(void)				\
+{								\
+	____key__##fun = hid_bpf_async_get_ctx();			\
+	if (____key__##fun < 0)					\
+		return ____key__##fun;				\
+	return 0;						\
+}								\
+static int HID_BPF_ASYNC_CB(____##fun##_cb)(struct hid_bpf_ctx *hctx)	\
+{								\
+	return fun(hctx);					\
+}								\
+typeof(fun(0)) fun
+
+#define HID_BPF_ASYNC_INIT(fun)	____async_init_##fun()
+#define HID_BPF_ASYNC_DELAYED_CALL(fun, ctx, delay)		\
+	hid_bpf_async_delayed_call(ctx, delay, ____key__##fun, ____##fun##_cb)
+
+/*
+ * internal cb for starting the delayed work callback in a workqueue.
+ */
+static int __start_wq_timer_cb(void *map, int *key, void *value)
+{
+	struct hid_bpf_async_map_elem *e = (struct hid_bpf_async_map_elem *)value;
+
+	bpf_wq_start(&e->wq, 0);
+
+	return 0;
+}
+
+static int hid_bpf_async_find_empty_key(void)
+{
+	int i;
+
+	bpf_for(i, 0, HID_BPF_ASYNC_MAX_CTX) {
+		struct hid_bpf_async_map_elem *elem;
+		int key = i;
+
+		elem = bpf_map_lookup_elem(&hid_bpf_async_ctx_map, &key);
+		if (!elem)
+			return -ENOMEM; /* should never happen */
+
+		bpf_spin_lock(&elem->lock);
+
+		if (elem->state == HID_BPF_ASYNC_STATE_UNSET) {
+			elem->state = HID_BPF_ASYNC_STATE_INITIALIZING;
+			bpf_spin_unlock(&elem->lock);
+			return i;
+		}
+
+		bpf_spin_unlock(&elem->lock);
+	}
+
+	return -EINVAL;
+}
+
+static int hid_bpf_async_get_ctx(void)
+{
+	int key = hid_bpf_async_find_empty_key();
+	struct hid_bpf_async_map_elem *elem;
+	int err;
+
+	if (key < 0)
+		return key;
+
+	elem = bpf_map_lookup_elem(&hid_bpf_async_ctx_map, &key);
+	if (!elem)
+		return -EINVAL;
+
+	err = bpf_timer_init(&elem->t, &hid_bpf_async_ctx_map, CLOCK_MONOTONIC);
+	if (err)
+		return err;
+
+	err = bpf_timer_set_callback(&elem->t, __start_wq_timer_cb);
+	if (err)
+		return err;
+
+	err = bpf_wq_init(&elem->wq, &hid_bpf_async_ctx_map, 0);
+	if (err)
+		return err;
+
+	elem->state = HID_BPF_ASYNC_STATE_INITIALIZED;
+
+	return key;
+}
+
+static inline u64 ms_to_ns(u64 milliseconds)
+{
+	return (u64)milliseconds * 1000UL * 1000UL;
+}
+
+static int hid_bpf_async_delayed_call(struct hid_bpf_ctx *hctx, u64 milliseconds, int key,
+			      hid_bpf_async_callback_t wq_cb)
+{
+	struct hid_bpf_async_map_elem *elem;
+	int err;
+
+	elem = bpf_map_lookup_elem(&hid_bpf_async_ctx_map, &key);
+	if (!elem)
+		return -EINVAL;
+
+	bpf_spin_lock(&elem->lock);
+	/* The wq must be:
+	 * - HID_BPF_ASYNC_STATE_INITIALIZED -> it's been initialized and ready to be called
+	 * - HID_BPF_ASYNC_STATE_RUNNING -> possible re-entry from the wq itself
+	 */
+	if (elem->state != HID_BPF_ASYNC_STATE_INITIALIZED &&
+	    elem->state != HID_BPF_ASYNC_STATE_RUNNING) {
+		bpf_spin_unlock(&elem->lock);
+		return -EINVAL;
+	}
+	elem->state = HID_BPF_ASYNC_STATE_STARTING;
+	bpf_spin_unlock(&elem->lock);
+
+	elem->hid = hctx->hid->id;
+
+	err = bpf_wq_set_callback(&elem->wq, wq_cb, 0);
+	if (err)
+		return err;
+
+	if (milliseconds) {
+		/* needed for every call because a cancel might unset this */
+		err = bpf_timer_set_callback(&elem->t, __start_wq_timer_cb);
+		if (err)
+			return err;
+
+		err = bpf_timer_start(&elem->t, ms_to_ns(milliseconds), 0);
+		if (err)
+			return err;
+
+		return 0;
+	}
+
+	return bpf_wq_start(&elem->wq, 0);
+}
+
+static inline int hid_bpf_async_call(struct hid_bpf_ctx *ctx, int key,
+				     hid_bpf_async_callback_t wq_cb)
+{
+	return hid_bpf_async_delayed_call(ctx, 0, key, wq_cb);
+}
+
+#endif /* __HID_BPF_ASYNC_H__ */

drivers/hid/bpf/progs/hid_bpf_helpers.h

···
 			      size_t buf__sz,
 			      enum hid_report_type type,
 			      enum hid_class_request reqtype) __ksym;
+extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
+				    __u8 *buf, size_t buf__sz) __weak __ksym;
+extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
+				enum hid_report_type type,
+				__u8 *data,
+				size_t buf__sz) __weak __ksym;
+extern int hid_bpf_try_input_report(struct hid_bpf_ctx *ctx,
+				    enum hid_report_type type,
+				    __u8 *data,
+				    size_t buf__sz) __weak __ksym;
+
+/* bpf_wq implementation */
+extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;
+extern int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) __weak __ksym;
+extern int bpf_wq_set_callback_impl(struct bpf_wq *wq,
+		int (callback_fn)(void *map, int *key, void *value),
+		unsigned int flags__k, void *aux__ign) __ksym;
+#define bpf_wq_set_callback(wq, cb, flags) \
+	bpf_wq_set_callback_impl(wq, cb, flags, NULL)
 
 #define HID_MAX_DESCRIPTOR_SIZE	4096
 #define HID_IGNORE_EVENT	-1

drivers/hid/hid-appletb-bl.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Backlight Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <[e-mail]>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/backlight.h>
+#include <linux/device.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_BL_ON			1
+#define APPLETB_BL_DIM			3
+#define APPLETB_BL_OFF			4
+
+#define HID_UP_APPLEVENDOR_TB_BL	0xff120000
+
+#define HID_VD_APPLE_TB_BRIGHTNESS	0xff120001
+#define HID_USAGE_AUX1			0xff120020
+#define HID_USAGE_BRIGHTNESS		0xff120021
+
+static int appletb_bl_def_brightness = 2;
+module_param_named(brightness, appletb_bl_def_brightness, int, 0444);
+MODULE_PARM_DESC(brightness, "Default brightness:\n"
+			 "    0 - Touchbar is off\n"
+			 "    1 - Dim brightness\n"
+			 "    [2] - Full brightness");
+
+struct appletb_bl {
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_device *bdev;
+
+	bool full_on;
+};
+
+static const u8 appletb_bl_brightness_map[] = {
+	APPLETB_BL_OFF,
+	APPLETB_BL_DIM,
+	APPLETB_BL_ON,
+};
+
+static int appletb_bl_set_brightness(struct appletb_bl *bl, u8 brightness)
+{
+	struct hid_report *report = bl->brightness_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_set_field(bl->aux1_field, 0, 1);
+	if (ret) {
+		hid_err(hdev, "Failed to set auxiliary field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(bl->brightness_field, 0, brightness);
+	if (ret) {
+		hid_err(hdev, "Failed to set brightness field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	if (!bl->full_on) {
+		ret = hid_hw_power(hdev, PM_HINT_FULLON);
+		if (ret < 0) {
+			hid_err(hdev, "Device didn't power on (%pe)\n", ERR_PTR(ret));
+			return ret;
+		}
+
+		bl->full_on = true;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	if (brightness == APPLETB_BL_OFF) {
+		hid_hw_power(hdev, PM_HINT_NORMAL);
+		bl->full_on = false;
+	}
+
+	return 0;
+}
+
+static int appletb_bl_update_status(struct backlight_device *bdev)
+{
+	struct appletb_bl *bl = bl_get_data(bdev);
+	u8 brightness;
+
+	if (backlight_is_blank(bdev))
+		brightness = APPLETB_BL_OFF;
+	else
+		brightness = appletb_bl_brightness_map[backlight_get_brightness(bdev)];
+
+	return appletb_bl_set_brightness(bl, brightness);
+}
+
+static const struct backlight_ops appletb_bl_backlight_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = appletb_bl_update_status,
+};
+
+static int appletb_bl_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_properties bl_props = { 0 };
+	struct device *dev = &hdev->dev;
+	struct appletb_bl *bl;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	aux1_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+				    HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_AUX1);
+
+	brightness_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+					  HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_BRIGHTNESS);
+
+	if (!aux1_field || !brightness_field)
+		return -ENODEV;
+
+	if (aux1_field->report != brightness_field->report)
+		return dev_err_probe(dev, -ENODEV, "Encountered unexpected report structure\n");
+
+	bl = devm_kzalloc(dev, sizeof(*bl), GFP_KERNEL);
+	if (!bl)
+		return -ENOMEM;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DRIVER);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hardware start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hardware open failed\n");
+		goto stop_hw;
+	}
+
+	bl->aux1_field = aux1_field;
+	bl->brightness_field = brightness_field;
+
+	ret = appletb_bl_set_brightness(bl,
+		appletb_bl_brightness_map[(appletb_bl_def_brightness > 2) ? 2 : appletb_bl_def_brightness]);
+
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set default touch bar brightness to %d\n",
+			      appletb_bl_def_brightness);
+		goto close_hw;
+	}
+
+	bl_props.type = BACKLIGHT_RAW;
+	bl_props.max_brightness = ARRAY_SIZE(appletb_bl_brightness_map) - 1;
+
+	bl->bdev = devm_backlight_device_register(dev, "appletb_backlight", dev, bl,
+						  &appletb_bl_backlight_ops, &bl_props);
+	if (IS_ERR(bl->bdev)) {
+		ret = PTR_ERR(bl->bdev);
+		dev_err_probe(dev, ret, "Failed to register backlight device\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, bl);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+
+	return ret;
+}
+
+static void appletb_bl_remove(struct hid_device *hdev)
+{
+	struct appletb_bl *bl = hid_get_drvdata(hdev);
+
+	appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id appletb_bl_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge DFR Brightness */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_bl_hid_ids);
+
+static struct hid_driver appletb_bl_hid_driver = {
+	.name = "hid-appletb-bl",
+	.id_table = appletb_bl_hid_ids,
+	.probe = appletb_bl_probe,
+	.remove = appletb_bl_remove,
+};
+module_hid_driver(appletb_bl_hid_driver);
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <[e-mail]>");
+MODULE_DESCRIPTION("MacBook Pro Touch Bar Backlight driver");
+MODULE_LICENSE("GPL");

drivers/hid/hid-appletb-kbd.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Keyboard Mode Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <[e-mail]>
+ * Copyright (c) 2024-2025 Aditya Garg <[e-mail]>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/usb.h>
+#include <linux/input.h>
+#include <linux/sysfs.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/backlight.h>
+#include <linux/timer.h>
+#include <linux/input/sparse-keymap.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_KBD_MODE_ESC	0
+#define APPLETB_KBD_MODE_FN	1
+#define APPLETB_KBD_MODE_SPCL	2
+#define APPLETB_KBD_MODE_OFF	3
+#define APPLETB_KBD_MODE_MAX	APPLETB_KBD_MODE_OFF
+
+#define APPLETB_DEVID_KEYBOARD	1
+#define APPLETB_DEVID_TRACKPAD	2
+
+#define HID_USAGE_MODE		0x00ff0004
+
+static int appletb_tb_def_mode = APPLETB_KBD_MODE_SPCL;
+module_param_named(mode, appletb_tb_def_mode, int, 0444);
+MODULE_PARM_DESC(mode, "Default touchbar mode:\n"
+			 "    0 - escape key only\n"
+			 "    1 - function-keys\n"
+			 "    [2] - special keys");
+
+static bool appletb_tb_fn_toggle = true;
+module_param_named(fntoggle, appletb_tb_fn_toggle, bool, 0644);
+MODULE_PARM_DESC(fntoggle, "Switch between Fn and media controls on pressing Fn key");
+
+static bool appletb_tb_autodim = true;
+module_param_named(autodim, appletb_tb_autodim, bool, 0644);
+MODULE_PARM_DESC(autodim, "Automatically dim and turn off the Touch Bar after some time");
+
+static int appletb_tb_dim_timeout = 60;
+module_param_named(dim_timeout, appletb_tb_dim_timeout, int, 0644);
+MODULE_PARM_DESC(dim_timeout, "Dim timeout in sec");
+
+static int appletb_tb_idle_timeout = 15;
+module_param_named(idle_timeout, appletb_tb_idle_timeout, int, 0644);
+MODULE_PARM_DESC(idle_timeout, "Idle timeout in sec");
+
+struct appletb_kbd {
+	struct hid_field *mode_field;
+	struct input_handler inp_handler;
+	struct input_handle kbd_handle;
+	struct input_handle tpd_handle;
+	struct backlight_device *backlight_dev;
+	struct timer_list inactivity_timer;
+	bool has_dimmed;
+	bool has_turned_off;
+	u8 saved_mode;
+	u8 current_mode;
+};
+
+static const struct key_entry appletb_kbd_keymap[] = {
+	{ KE_KEY, KEY_ESC, { KEY_ESC } },
+	{ KE_KEY, KEY_F1,  { KEY_BRIGHTNESSDOWN } },
+	{ KE_KEY, KEY_F2,  { KEY_BRIGHTNESSUP } },
+	{ KE_KEY, KEY_F3,  { KEY_RESERVED } },
+	{ KE_KEY, KEY_F4,  { KEY_RESERVED } },
+	{ KE_KEY, KEY_F5,  { KEY_KBDILLUMDOWN } },
+	{ KE_KEY, KEY_F6,  { KEY_KBDILLUMUP } },
+	{ KE_KEY, KEY_F7,  { KEY_PREVIOUSSONG } },
+	{ KE_KEY, KEY_F8,  { KEY_PLAYPAUSE } },
+	{ KE_KEY, KEY_F9,  { KEY_NEXTSONG } },
+	{ KE_KEY, KEY_F10, { KEY_MUTE } },
+	{ KE_KEY, KEY_F11, { KEY_VOLUMEDOWN } },
+	{ KE_KEY, KEY_F12, { KEY_VOLUMEUP } },
+	{ KE_END, 0 }
+};
+
+static int appletb_kbd_set_mode(struct appletb_kbd *kbd, u8 mode)
+{
+	struct hid_report *report = kbd->mode_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_hw_power(hdev, PM_HINT_FULLON);
+	if (ret) {
+		hid_err(hdev, "Device didn't resume (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(kbd->mode_field, 0, mode);
+	if (ret) {
+		hid_err(hdev, "Failed to set mode field to %u (%pe)\n", mode, ERR_PTR(ret));
+		goto power_normal;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	kbd->current_mode = mode;
+
+power_normal:
+	hid_hw_power(hdev, PM_HINT_NORMAL);
+
+	return ret;
+}
+
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct appletb_kbd *kbd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", kbd->current_mode);
+}
+
+static ssize_t mode_store(struct device *dev,
+			  struct device_attribute *attr,
+			  const char *buf, size_t size)
+{
+	struct appletb_kbd *kbd = dev_get_drvdata(dev);
+	u8 mode;
+	int ret;
+
+	ret = kstrtou8(buf, 0, &mode);
+	if (ret)
+		return ret;
+
+	if (mode > APPLETB_KBD_MODE_MAX)
+		return -EINVAL;
+
+	ret = appletb_kbd_set_mode(kbd, mode);
+
+	return ret < 0 ? ret : size;
+}
+static DEVICE_ATTR_RW(mode);
+
+static struct attribute *appletb_kbd_attrs[] = {
+	&dev_attr_mode.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(appletb_kbd);
+
+static int appletb_tb_key_to_slot(unsigned int code)
+{
+	switch (code) {
+	case KEY_ESC:
+		return 0;
+	case KEY_F1 ... KEY_F10:
+		return code - KEY_F1 + 1;
+	case KEY_F11 ... KEY_F12:
+		return code - KEY_F11 + 11;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static void appletb_inactivity_timer(struct timer_list *t)
+{
+	struct appletb_kbd *kbd = from_timer(kbd, t, inactivity_timer);
+
+	if (kbd->backlight_dev && appletb_tb_autodim) {
+		if (!kbd->has_dimmed) {
+			backlight_device_set_brightness(kbd->backlight_dev, 1);
+			kbd->has_dimmed = true;
+			mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_idle_timeout * 1000));
+		} else if (!kbd->has_turned_off) {
+			backlight_device_set_brightness(kbd->backlight_dev, 0);
+			kbd->has_turned_off = true;
+		}
+	}
+}
+
+static void reset_inactivity_timer(struct appletb_kbd *kbd)
+{
+	if (kbd->backlight_dev && appletb_tb_autodim) {
+		if (kbd->has_dimmed || kbd->has_turned_off) {
+			backlight_device_set_brightness(kbd->backlight_dev, 2);
+			kbd->has_dimmed = false;
+			kbd->has_turned_off = false;
+		}
+		mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_dim_timeout * 1000));
+	}
+}
+
+static int appletb_kbd_hid_event(struct hid_device *hdev, struct hid_field *field,
+				      struct hid_usage *usage, __s32 value)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+	struct key_entry *translation;
+	struct input_dev *input;
+	int slot;
+
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_KEYBOARD || usage->type != EV_KEY)
+		return 0;
+
+	input = field->hidinput->input;
+
+	/*
+	 * Skip non-touch-bar keys.
+	 *
+	 * Either the touch bar itself or usbhid generate a slew of key-down
+	 * events for all the meta keys. None of which we're at all interested
+	 * in.
+	 */
+	slot = appletb_tb_key_to_slot(usage->code);
+	if (slot < 0)
+		return 0;
+
+	reset_inactivity_timer(kbd);
+
+	translation = sparse_keymap_entry_from_scancode(input, usage->code);
+
+	if (translation && kbd->current_mode == APPLETB_KBD_MODE_SPCL) {
+		input_event(input, usage->type, translation->keycode, value);
+
+		return 1;
+	}
+
+	return kbd->current_mode == APPLETB_KBD_MODE_OFF;
+}
+
+static void appletb_kbd_inp_event(struct input_handle *handle, unsigned int type,
+			      unsigned int code, int value)
+{
+	struct appletb_kbd *kbd = handle->private;
+
+	reset_inactivity_timer(kbd);
+
+	if (type == EV_KEY && code == KEY_FN && appletb_tb_fn_toggle &&
+		(kbd->current_mode == APPLETB_KBD_MODE_SPCL ||
+		 kbd->current_mode == APPLETB_KBD_MODE_FN)) {
+		if (value == 1) {
+			kbd->saved_mode = kbd->current_mode;
+			appletb_kbd_set_mode(kbd, kbd->current_mode == APPLETB_KBD_MODE_SPCL
+						? APPLETB_KBD_MODE_FN : APPLETB_KBD_MODE_SPCL);
+		} else if (value == 0) {
+			if (kbd->saved_mode != kbd->current_mode)
+				appletb_kbd_set_mode(kbd, kbd->saved_mode);
+		}
+	}
+}
+
+static int appletb_kbd_inp_connect(struct input_handler *handler,
+			       struct input_dev *dev,
+			       const struct input_device_id *id)
+{
+	struct appletb_kbd *kbd = handler->private;
+	struct input_handle *handle;
+	int rc;
+
+	if (id->driver_info == APPLETB_DEVID_KEYBOARD) {
+		handle = &kbd->kbd_handle;
+		handle->name = "tbkbd";
+	} else if (id->driver_info == APPLETB_DEVID_TRACKPAD) {
+		handle = &kbd->tpd_handle;
+		handle->name = "tbtpd";
+	} else {
+		return -ENOENT;
+	}
+
+	if (handle->dev)
+		return -EEXIST;
+
+	handle->open = 0;
+	handle->dev = input_get_device(dev);
+	handle->handler = handler;
+	handle->private = kbd;
+
+	rc = input_register_handle(handle);
+	if (rc)
+		goto err_free_dev;
+
+	rc = input_open_device(handle);
+	if (rc)
+		goto err_unregister_handle;
+
+	return 0;
+
+ err_unregister_handle:
+	input_unregister_handle(handle);
+ err_free_dev:
+	input_put_device(handle->dev);
+	handle->dev = NULL;
+	return rc;
+}
+
+static void appletb_kbd_inp_disconnect(struct input_handle *handle)
+{
+	input_close_device(handle);
+	input_unregister_handle(handle);
+
+	input_put_device(handle->dev);
+	handle->dev = NULL;
+}
+
+static int appletb_kbd_input_configured(struct hid_device *hdev, struct hid_input *hidinput)
+{
+	int idx;
+	struct input_dev *input = hidinput->input;
+
+	/*
+	 * Clear various input capabilities that are blindly set by the hid
+	 * driver (usbkbd.c)
+	 */
+	memset(input->evbit, 0, sizeof(input->evbit));
+	memset(input->keybit, 0, sizeof(input->keybit));
+	memset(input->ledbit, 0, sizeof(input->ledbit));
+
+	__set_bit(EV_REP, input->evbit);
+
+	sparse_keymap_setup(input, appletb_kbd_keymap, NULL);
+
+	for (idx = 0; appletb_kbd_keymap[idx].type != KE_END; idx++)
+		input_set_capability(input, EV_KEY, appletb_kbd_keymap[idx].code);
+
+	return 0;
+}
+
+static const struct input_device_id appletb_kbd_input_devices[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_BUS |
+			INPUT_DEVICE_ID_MATCH_VENDOR |
+			INPUT_DEVICE_ID_MATCH_KEYBIT,
+		.bustype = BUS_USB,
+		.vendor = USB_VENDOR_ID_APPLE,
+		.keybit = { [BIT_WORD(KEY_FN)] = BIT_MASK(KEY_FN) },
+		.driver_info = APPLETB_DEVID_KEYBOARD,
+	},
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_BUS |
+			INPUT_DEVICE_ID_MATCH_VENDOR |
+			INPUT_DEVICE_ID_MATCH_KEYBIT,
+		.bustype = BUS_USB,
+		.vendor = USB_VENDOR_ID_APPLE,
+		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
+		.driver_info = APPLETB_DEVID_TRACKPAD,
+	},
+	{ }
+};
+
+static bool appletb_kbd_match_internal_device(struct input_handler *handler,
+					  struct input_dev *inp_dev)
+{
+	struct device *dev = &inp_dev->dev;
+
+	/* in kernel: dev && !is_usb_device(dev) */
+	while (dev && !(dev->type && dev->type->name &&
+			!strcmp(dev->type->name, "usb_device")))
+		dev = dev->parent;
+
+	/*
+	 * Apple labels all their internal keyboards and trackpads as such,
+	 * instead of maintaining an ever expanding list of product-id's we
+	 * just look at the device's product name.
+	 */
+	if (dev)
+		return !!strstr(to_usb_device(dev)->product, "Internal Keyboard");
+
+	return false;
+}
+
+static int appletb_kbd_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct appletb_kbd *kbd;
+	struct device *dev = &hdev->dev;
+	struct hid_field *mode_field;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	mode_field = hid_find_field(hdev, HID_OUTPUT_REPORT,
+				    HID_GD_KEYBOARD, HID_USAGE_MODE);
+	if (!mode_field)
+		return -ENODEV;
+
+	kbd = devm_kzalloc(dev, sizeof(*kbd), GFP_KERNEL);
+	if (!kbd)
+		return -ENOMEM;
+
+	kbd->mode_field = mode_field;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDINPUT);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hw start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hw open failed\n");
+		goto stop_hw;
+	}
+
+	kbd->backlight_dev = backlight_device_get_by_name("appletb_backlight");
+	if (!kbd->backlight_dev) {
+		dev_err_probe(dev, -ENODEV, "Failed to get backlight device\n");
+	} else {
+		backlight_device_set_brightness(kbd->backlight_dev, 2);
+		timer_setup(&kbd->inactivity_timer, appletb_inactivity_timer, 0);
+		mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_dim_timeout * 1000));
+	}
+
+	kbd->inp_handler.event = appletb_kbd_inp_event;
+	kbd->inp_handler.connect = appletb_kbd_inp_connect;
+	kbd->inp_handler.disconnect = appletb_kbd_inp_disconnect;
+	kbd->inp_handler.name = "appletb";
+	kbd->inp_handler.id_table = appletb_kbd_input_devices;
+	kbd->inp_handler.match = appletb_kbd_match_internal_device;
+	kbd->inp_handler.private = kbd;
+
+	ret = input_register_handler(&kbd->inp_handler);
+	if (ret) {
+		dev_err_probe(dev, ret, "Unable to register keyboard handler\n");
+		goto close_hw;
+	}
+
+	ret = appletb_kbd_set_mode(kbd, appletb_tb_def_mode);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set touchbar mode\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, kbd);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void appletb_kbd_remove(struct hid_device *hdev)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
+
+	input_unregister_handler(&kbd->inp_handler);
+	del_timer_sync(&kbd->inactivity_timer);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+#ifdef CONFIG_PM
+static int appletb_kbd_suspend(struct hid_device *hdev, pm_message_t msg)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	kbd->saved_mode = kbd->current_mode;
+	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
+
+	return 0;
+}
+
+static int appletb_kbd_reset_resume(struct hid_device *hdev)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	appletb_kbd_set_mode(kbd, kbd->saved_mode);
+
+	return 0;
+}
+#endif
+
+static const struct hid_device_id appletb_kbd_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge Display */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_kbd_hid_ids);
+
+static struct hid_driver appletb_kbd_hid_driver = {
+	.name = "hid-appletb-kbd",
+	.id_table = appletb_kbd_hid_ids,
+	.probe = appletb_kbd_probe,
+	.remove = appletb_kbd_remove,
+	.event = appletb_kbd_hid_event,
+	.input_configured = appletb_kbd_input_configured,
+#ifdef CONFIG_PM
+	.suspend = appletb_kbd_suspend,
+	.reset_resume = appletb_kbd_reset_resume,
+#endif
+	.driver.dev_groups = appletb_kbd_groups,
+};
+module_hid_driver(appletb_kbd_hid_driver);
+
+/* The backlight driver should be loaded before the keyboard driver is initialised */
+MODULE_SOFTDEP("pre: hid_appletb_bl");
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <[e-mail]>");
+MODULE_AUTHOR("Aditya Garg <[e-mail]>");
+MODULE_DESCRIPTION("MacBook Pro Touch Bar Keyboard Mode driver");
+MODULE_LICENSE("GPL");

drivers/hid/hid-core.c

···
 		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 		break;
 	default:
-		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
+		if (item->tag >= HID_MAIN_ITEM_TAG_RESERVED_MIN &&
+			item->tag <= HID_MAIN_ITEM_TAG_RESERVED_MAX)
+			hid_warn(parser->device, "reserved main item tag 0x%x\n", item->tag);
+		else
+			hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 		ret = 0;
 	}
 

drivers/hid/hid-google-hammer.c

···
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
-#include <linux/pm_wakeup.h>
 #include <linux/unaligned.h>
 
 #include "hid-ids.h"

drivers/hid/hid-ids.h

···
 #define USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT 0x8102
 #define USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY 0x8302
 
+#define USB_VENDOR_ID_ASETEK			0x2433
+#define USB_DEVICE_ID_ASETEK_INVICTA		0xf300
+#define USB_DEVICE_ID_ASETEK_FORTE		0xf301
+#define USB_DEVICE_ID_ASETEK_LA_PRIMA		0xf303
+#define USB_DEVICE_ID_ASETEK_TONY_KANAAN	0xf306
+
 #define USB_VENDOR_ID_ASUS		0x0486
 #define USB_DEVICE_ID_ASUS_T91MT	0x0185
 #define USB_DEVICE_ID_ASUSTEK_MULTITOUCH_YFO	0x0186
···
 #define USB_VENDOR_ID_BTC		0x046e
 #define USB_DEVICE_ID_BTC_EMPREX_REMOTE	0x5578
 #define USB_DEVICE_ID_BTC_EMPREX_REMOTE_2	0x5577
+
+#define USB_VENDOR_ID_CAMMUS		0x3416
+#define USB_DEVICE_ID_CAMMUS_C5		0x0301
+#define USB_DEVICE_ID_CAMMUS_C12	0x0302
 
 #define USB_VENDOR_ID_CANDO		0x2087
 #define USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH 0x0703
···
 
 #define USB_VENDOR_ID_EVISION           0x320f
 #define USB_DEVICE_ID_EVISION_ICL01     0x5041
+
+#define USB_VENDOR_ID_FFBEAST		0x045b
+#define USB_DEVICE_ID_FFBEAST_JOYSTICK	0x58f9
+#define USB_DEVICE_ID_FFBEAST_RUDDER	0x5968
+#define USB_DEVICE_ID_FFBEAST_WHEEL	0x59d7
 
 #define USB_VENDOR_ID_FLATFROG		0x25b5
 #define USB_DEVICE_ID_MULTITOUCH_3200	0x0002
···
 #define I2C_DEVICE_ID_LG_8001		0x8001
 #define I2C_DEVICE_ID_LG_7010		0x7010
 
+#define USB_VENDOR_ID_LITE_STAR		0x11ff
+#define USB_DEVICE_ID_PXN_V10		0x3245
+#define USB_DEVICE_ID_PXN_V12		0x1212
+#define USB_DEVICE_ID_PXN_V12_LITE	0x1112
+#define USB_DEVICE_ID_PXN_V12_LITE_2	0x1211
+#define USB_DEVICE_LITE_STAR_GT987_FF	0x2141
+
 #define USB_VENDOR_ID_LOGITECH		0x046d
 #define USB_DEVICE_ID_LOGITECH_Z_10_SPK	0x0a07
 #define USB_DEVICE_ID_LOGITECH_AUDIOHUB 0x0a0e
···
 
 #define USB_VENDOR_ID_MONTEREY		0x0566
 #define USB_DEVICE_ID_GENIUS_KB29E	0x3004
+
+#define USB_VENDOR_ID_MOZA		0x346e
+#define USB_DEVICE_ID_MOZA_R3		0x0005
+#define USB_DEVICE_ID_MOZA_R3_2		0x0015
+#define USB_DEVICE_ID_MOZA_R5		0x0004
+#define USB_DEVICE_ID_MOZA_R5_2		0x0014
+#define USB_DEVICE_ID_MOZA_R9		0x0002
+#define USB_DEVICE_ID_MOZA_R9_2		0x0012
+#define USB_DEVICE_ID_MOZA_R12		0x0006
+#define USB_DEVICE_ID_MOZA_R12_2	0x0016
+#define USB_DEVICE_ID_MOZA_R16_R21	0x0000
+#define USB_DEVICE_ID_MOZA_R16_R21_2	0x0010
 
 #define USB_VENDOR_ID_MSI		0x1770
 #define USB_DEVICE_ID_MSI_GT683R_LED_PANEL 0xff00
···
 #define USB_DEVICE_ID_VELLEMAN_K8055_LAST	0x5503
 #define USB_DEVICE_ID_VELLEMAN_K8061_FIRST	0x8061
 #define USB_DEVICE_ID_VELLEMAN_K8061_LAST	0x8068
+
+#define USB_VENDOR_ID_VRS	0x0483
+#define USB_DEVICE_ID_VRS_DFP	0xa355
 
 #define USB_VENDOR_ID_VTL		0x0306
 #define USB_DEVICE_ID_VTL_MULTITOUCH_FF3F	0xff3f

drivers/hid/hid-lenovo.c

···
 			if (hdev->product == USB_DEVICE_ID_LENOVO_X12_TAB) {
 				report_key_event(input, KEY_RFKILL);
 				return 1;
-			} else {
-				platform_profile_cycle();
-				return 1;
 			}
-			return 0;
+			platform_profile_cycle();
+			return 1;
 		case TP_X12_RAW_HOTKEY_FN_F10:
 			/* TAB1 has PICKUP Phone and TAB2 use Snipping tool*/
 			(hdev->product == USB_DEVICE_ID_LENOVO_X12_TAB) ?
···
 	if (unlikely((hdev->product == USB_DEVICE_ID_LENOVO_X12_TAB
 			|| hdev->product == USB_DEVICE_ID_LENOVO_X12_TAB2)
 			&& size >= 3 && report->id == 0x03))
-		return lenovo_raw_event_TP_X12_tab(hdev, le32_to_cpu(*(u32 *)data));
+		return lenovo_raw_event_TP_X12_tab(hdev, le32_to_cpu(*(__le32 *)data));
 
 	return 0;
 }

drivers/hid/hid-lg-g15.c

···
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/leds.h>
+#include <linux/led-class-multicolor.h>
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/sched.h>
 #include <linux/usb.h>
 #include <linux/wait.h>
+#include <dt-bindings/leds/common.h>
 
 #include "hid-ids.h"
 
···
 };
 
 struct lg_g15_led {
-	struct led_classdev cdev;
+	union {
+		struct led_classdev cdev;
+		struct led_classdev_mc mcdev;
+	};
 	enum led_brightness brightness;
 	enum lg_g15_led_type led;
+	/* Used to store initial color intensities before subled_info is allocated */
 	u8 red, green, blue;
 };
 
···
 				 struct lg_g15_led *g15_led,
 				 enum led_brightness brightness)
 {
+	struct mc_subled *subleds = g15_led->mcdev.subled_info;
 	int ret;
 
+	led_mc_calc_color_components(&g15_led->mcdev, brightness);
+
 	g15->transfer_buf[0] = 5 + g15_led->led;
-	g15->transfer_buf[1] =
-		DIV_ROUND_CLOSEST(g15_led->red * brightness, 255);
-	g15->transfer_buf[2] =
-		DIV_ROUND_CLOSEST(g15_led->green * brightness, 255);
-	g15->transfer_buf[3] =
-		DIV_ROUND_CLOSEST(g15_led->blue * brightness, 255);
+	g15->transfer_buf[1] = subleds[0].brightness;
+	g15->transfer_buf[2] = subleds[1].brightness;
+	g15->transfer_buf[3] = subleds[2].brightness;
 
 	ret = hid_hw_raw_request(g15->hdev,
 				 LG_G510_FEATURE_BACKLIGHT_RGB + g15_led->led,
···
 static int lg_g510_kbd_led_set(struct led_classdev *led_cdev,
 			       enum led_brightness brightness)
 {
+	struct led_classdev_mc *mc = lcdev_to_mccdev(led_cdev);
 	struct lg_g15_led *g15_led =
-		container_of(led_cdev, struct lg_g15_led, cdev);
+		container_of(mc, struct lg_g15_led, mcdev);
 	struct lg_g15_data *g15 = dev_get_drvdata(led_cdev->dev->parent);
 	int ret;
 
···
 
 static enum led_brightness lg_g510_kbd_led_get(struct led_classdev *led_cdev)
 {
+	struct led_classdev_mc *mc = lcdev_to_mccdev(led_cdev);
 	struct lg_g15_led *g15_led =
-		container_of(led_cdev, struct lg_g15_led, cdev);
+		container_of(mc, struct lg_g15_led, mcdev);
 
 	return g15_led->brightness;
 }
 
-static ssize_t color_store(struct device *dev, struct device_attribute *attr,
-			   const char *buf, size_t count)
-{
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct lg_g15_led *g15_led =
-		container_of(led_cdev, struct lg_g15_led, cdev);
-	struct lg_g15_data *g15 = dev_get_drvdata(led_cdev->dev->parent);
-	unsigned long value;
-	int ret;
-
-	if (count < 7 || (count == 8 && buf[7] != '\n') || count > 8)
-		return -EINVAL;
-
-	if (buf[0] != '#')
-		return -EINVAL;
-
-	ret = kstrtoul(buf + 1, 16, &value);
-	if (ret)
-		return ret;
-
-	mutex_lock(&g15->mutex);
-	g15_led->red   = (value & 0xff0000) >> 16;
-	g15_led->green = (value & 0x00ff00) >> 8;
-	g15_led->blue  = (value & 0x0000ff);
-	ret = lg_g510_kbd_led_write(g15, g15_led, g15_led->brightness);
-	mutex_unlock(&g15->mutex);
-
-	return (ret < 0) ? ret : count;
-}
-
-static ssize_t color_show(struct device *dev, struct device_attribute *attr,
-			  char *buf)
-{
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct lg_g15_led *g15_led =
-		container_of(led_cdev, struct lg_g15_led, cdev);
-	struct lg_g15_data *g15 = dev_get_drvdata(led_cdev->dev->parent);
-	ssize_t ret;
-
-	mutex_lock(&g15->mutex);
-	ret = sprintf(buf, "#%02x%02x%02x\n",
-		      g15_led->red, g15_led->green, g15_led->blue);
-	mutex_unlock(&g15->mutex);
-
-	return ret;
-}
-
-static DEVICE_ATTR_RW(color);
-
-static struct attribute *lg_g510_kbd_led_attrs[] = {
-	&dev_attr_color.attr,
-	NULL,
-};
-
-static const struct attribute_group lg_g510_kbd_led_group = {
-	.attrs = lg_g510_kbd_led_attrs,
-};
-
-static const struct attribute_group *lg_g510_kbd_led_groups[] = {
-	&lg_g510_kbd_led_group,
-	NULL,
-};
-
 static void lg_g510_leds_sync_work(struct work_struct *work)
 {
 	struct lg_g15_data *g15 = container_of(work, struct lg_g15_data, work);
+	struct lg_g15_led *g15_led = &g15->leds[LG_G15_KBD_BRIGHTNESS];
 
 	mutex_lock(&g15->mutex);
-	lg_g510_kbd_led_write(g15, &g15->leds[LG_G15_KBD_BRIGHTNESS],
-			      g15->leds[LG_G15_KBD_BRIGHTNESS].brightness);
+	lg_g510_kbd_led_write(g15, g15_led, g15_led->brightness);
 	mutex_unlock(&g15->mutex);
 }
 
···
 	hid_hw_close(hdev);
 }
 
+static void lg_g15_setup_led_rgb(struct lg_g15_data *g15, int index)
+{
+	int i;
+	struct mc_subled *subled_info;
+
+	g15->leds[index].mcdev.led_cdev.brightness_set_blocking =
+		lg_g510_kbd_led_set;
+	g15->leds[index].mcdev.led_cdev.brightness_get =
+		lg_g510_kbd_led_get;
+	g15->leds[index].mcdev.led_cdev.max_brightness = 255;
+	g15->leds[index].mcdev.num_colors = 3;
+
+	subled_info = devm_kcalloc(&g15->hdev->dev, 3, sizeof(*subled_info), GFP_KERNEL);
+	if (!subled_info)
+		return;
+
+	for (i = 0; i < 3; i++) {
+		switch (i + 1) {
+		case LED_COLOR_ID_RED:
+			subled_info[i].color_index = LED_COLOR_ID_RED;
+			subled_info[i].intensity = g15->leds[index].red;
+			break;
+		case LED_COLOR_ID_GREEN:
+			subled_info[i].color_index = LED_COLOR_ID_GREEN;
+			subled_info[i].intensity = g15->leds[index].green;
+			break;
+		case LED_COLOR_ID_BLUE:
+			subled_info[i].color_index = LED_COLOR_ID_BLUE;
+			subled_info[i].intensity = g15->leds[index].blue;
+			break;
+		}
+		subled_info[i].channel = i;
+	}
+	g15->leds[index].mcdev.subled_info = subled_info;
+}
+
 static int lg_g15_register_led(struct lg_g15_data *g15, int i, const char *name)
 {
+	int ret;
+
 	g15->leds[i].led = i;
 	g15->leds[i].cdev.name = name;
 
···
 		} else {
 			g15->leds[i].cdev.max_brightness = 1;
 		}
+		ret = devm_led_classdev_register(&g15->hdev->dev, &g15->leds[i].cdev);
 		break;
 	case LG_G510:
 	case LG_G510_USB_AUDIO:
···
 			g15->leds[i].cdev.name = "g15::power_on_backlight_val";
 			fallthrough;
 		case LG_G15_KBD_BRIGHTNESS:
-			g15->leds[i].cdev.brightness_set_blocking =
-				lg_g510_kbd_led_set;
-			g15->leds[i].cdev.brightness_get =
-				lg_g510_kbd_led_get;
-			g15->leds[i].cdev.max_brightness = 255;
-			g15->leds[i].cdev.groups = lg_g510_kbd_led_groups;
+			/* register multicolor LED */
+			lg_g15_setup_led_rgb(g15, i);
+			ret = devm_led_classdev_multicolor_register_ext(&g15->hdev->dev,
+									&g15->leds[i].mcdev,
+									NULL);
 			break;
 		default:
 			g15->leds[i].cdev.brightness_set_blocking =
···
 			g15->leds[i].cdev.brightness_get =
 				lg_g510_mkey_led_get;
 			g15->leds[i].cdev.max_brightness = 1;
+			ret = devm_led_classdev_register(&g15->hdev->dev, &g15->leds[i].cdev);
 		}
 		break;
 	}
 
-	return devm_led_classdev_register(&g15->hdev->dev, &g15->leds[i].cdev);
+	return ret;
 }
 
 /* Common input device init code shared between keyboards and Z-10 speaker handling */

drivers/hid/hid-plantronics.c

···
  *  Copyright (c) 2015-2018 Terry Junge <[e-mail]>
  */
 
-/*
- */
-
 #include "hid-ids.h"
 
 #include <linux/hid.h>
···
 
 #define PLT_VOL_UP		0x00b1
 #define PLT_VOL_DOWN		0x00b2
+#define PLT_MIC_MUTE		0x00b5
 
 #define PLT1_VOL_UP		(PLT_HID_1_0_PAGE | PLT_VOL_UP)
 #define PLT1_VOL_DOWN		(PLT_HID_1_0_PAGE | PLT_VOL_DOWN)
+#define PLT1_MIC_MUTE		(PLT_HID_1_0_PAGE | PLT_MIC_MUTE)
 #define PLT2_VOL_UP		(PLT_HID_2_0_PAGE | PLT_VOL_UP)
 #define PLT2_VOL_DOWN		(PLT_HID_2_0_PAGE | PLT_VOL_DOWN)
+#define PLT2_MIC_MUTE		(PLT_HID_2_0_PAGE | PLT_MIC_MUTE)
+#define HID_TELEPHONY_MUTE	(HID_UP_TELEPHONY | 0x2f)
+#define HID_CONSUMER_MUTE	(HID_UP_CONSUMER | 0xe2)
 
 #define PLT_DA60		0xda60
 #define PLT_BT300_MIN		0x0413
 #define PLT_BT300_MAX		0x0418
 
-
-#define PLT_ALLOW_CONSUMER (field->application == HID_CP_CONSUMERCONTROL && \
-			    (usage->hid & HID_USAGE_PAGE) == HID_UP_CONSUMER)
-
-#define PLT_QUIRK_DOUBLE_VOLUME_KEYS BIT(0)
-#define PLT_QUIRK_FOLLOWED_OPPOSITE_VOLUME_KEYS BIT(1)
-
 #define PLT_DOUBLE_KEY_TIMEOUT 5 /* ms */
-#define PLT_FOLLOWED_OPPOSITE_KEY_TIMEOUT 220 /* ms */
 
 struct plt_drv_data {
 	unsigned long device_type;
-	unsigned long last_volume_key_ts;
-	u32 quirks;
+	unsigned long last_key_ts;
+	unsigned long double_key_to;
+	__u16 last_key;
 };
 
 static int plantronics_input_mapping(struct hid_device *hdev,
···
 	unsigned short mapped_key;
 	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
 	unsigned long plt_type = drv_data->device_type;
+	int allow_mute = usage->hid == HID_TELEPHONY_MUTE;
+	int allow_consumer = field->application == HID_CP_CONSUMERCONTROL &&
+			(usage->hid & HID_USAGE_PAGE) == HID_UP_CONSUMER &&
+			usage->hid != HID_CONSUMER_MUTE;
 
 	/* special case for PTT products */
 	if (field->application == HID_GD_JOYSTICK)
 		goto defaulted;
 
-	/* handle volume up/down mapping */
 	/* non-standard types or multi-HID interfaces - plt_type is PID */
 	if (!(plt_type & HID_USAGE_PAGE)) {
 		switch (plt_type) {
 		case PLT_DA60:
-			if (PLT_ALLOW_CONSUMER)
+			if (allow_consumer)
 				goto defaulted;
-			goto ignored;
+			if (usage->hid == HID_CONSUMER_MUTE) {
+				mapped_key = KEY_MICMUTE;
+				goto mapped;
+			}
+			break;
 		default:
-			if (PLT_ALLOW_CONSUMER)
+			if (allow_consumer || allow_mute)
 				goto defaulted;
 		}
+		goto ignored;
 	}
-	/* handle standard types - plt_type is 0xffa0uuuu or 0xffa2uuuu */
-	/* 'basic telephony compliant' - allow default consumer page map */
-	else if ((plt_type & HID_USAGE) >= PLT_BASIC_TELEPHONY &&
-		 (plt_type & HID_USAGE) != PLT_BASIC_EXCEPTION) {
-		if (PLT_ALLOW_CONSUMER)
-			goto defaulted;
-	}
-	/* not 'basic telephony' - apply legacy mapping */
-	/* only map if the field is in the device's primary vendor page */
-	else if (!((field->application ^ plt_type) & HID_USAGE_PAGE)) {
+
+	/* handle standard consumer control mapping */
+	/* and standard telephony mic mute mapping */
+	if (allow_consumer || allow_mute)
+		goto defaulted;
+
+	/* handle vendor unique types - plt_type is 0xffa0uuuu or 0xffa2uuuu */
+	/* if not 'basic telephony compliant' - map vendor unique controls */
+	if (!((plt_type & HID_USAGE) >= PLT_BASIC_TELEPHONY &&
+	      (plt_type & HID_USAGE) != PLT_BASIC_EXCEPTION) &&
+	      !((field->application ^ plt_type) & HID_USAGE_PAGE))
 		switch (usage->hid) {
 		case PLT1_VOL_UP:
 		case PLT2_VOL_UP:
···
 		case PLT2_VOL_DOWN:
 			mapped_key = KEY_VOLUMEDOWN;
 			goto mapped;
+		case PLT1_MIC_MUTE:
+		case PLT2_MIC_MUTE:
+			mapped_key = KEY_MICMUTE;
+			goto mapped;
 		}
-	}
 
 /*
  * Future mapping of call control or other usages,
···
  */
 
 ignored:
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - ignored\n",
+		usage->hid, field->application);
 	return -1;
 
 defaulted:
···
 			     struct hid_usage *usage, __s32 value)
 {
 	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+	unsigned long prev_tsto, cur_ts;
+	__u16 prev_key, cur_key;
 
-	if (drv_data->quirks & PLT_QUIRK_DOUBLE_VOLUME_KEYS) {
-		unsigned long prev_ts, cur_ts;
+	/* Usages are filtered in plantronics_usages. */
 
-		/* Usages are filtered in plantronics_usages. */
+	/* HZ too low for ms resolution - double key detection disabled */
+	/* or it is a key release - handle key presses only. */
+	if (!drv_data->double_key_to || !value)
+		return 0;
 
-		if (!value) /* Handle key presses only. */
-			return 0;
+	prev_tsto = drv_data->last_key_ts + drv_data->double_key_to;
+	cur_ts = drv_data->last_key_ts = jiffies;
+	prev_key = drv_data->last_key;
+	cur_key = drv_data->last_key = usage->code;
 
-		prev_ts = drv_data->last_volume_key_ts;
-		cur_ts = jiffies;
-		if (jiffies_to_msecs(cur_ts - prev_ts) <= PLT_DOUBLE_KEY_TIMEOUT)
-			return 1; /* Ignore the repeated key. */
-
-		drv_data->last_volume_key_ts = cur_ts;
+	/* If the same key occurs in <= double_key_to -- ignore it */
+	if (prev_key == cur_key && time_before_eq(cur_ts, prev_tsto)) {
+		hid_dbg(hdev, "double key %d ignored\n", cur_key);
+		return 1; /* Ignore the repeated key. */
 	}
-	if (drv_data->quirks & PLT_QUIRK_FOLLOWED_OPPOSITE_VOLUME_KEYS) {
-		unsigned long prev_ts, cur_ts;
-
-		/* Usages are filtered in plantronics_usages. */
-
-		if (!value) /* Handle key presses only. */
-			return 0;
-
-		prev_ts = drv_data->last_volume_key_ts;
-		cur_ts = jiffies;
-		if (jiffies_to_msecs(cur_ts - prev_ts) <= PLT_FOLLOWED_OPPOSITE_KEY_TIMEOUT)
-			return 1; /* Ignore the followed opposite volume key. */
-
-		drv_data->last_volume_key_ts = cur_ts;
-	}
-
 	return 0;
 }
 
···
 	ret = hid_parse(hdev);
 	if (ret) {
 		hid_err(hdev, "parse failed\n");
-		goto err;
+		return ret;
 	}
 
 	drv_data->device_type = plantronics_device_type(hdev);
-	drv_data->quirks = id->driver_data;
-	drv_data->last_volume_key_ts = jiffies - msecs_to_jiffies(PLT_DOUBLE_KEY_TIMEOUT);
+	drv_data->double_key_to = msecs_to_jiffies(PLT_DOUBLE_KEY_TIMEOUT);
+	drv_data->last_key_ts = jiffies - drv_data->double_key_to;
+
+	/* if HZ does not allow ms resolution - disable double key detection */
+	if (drv_data->double_key_to < PLT_DOUBLE_KEY_TIMEOUT)
+		drv_data->double_key_to = 0;
 
 	hid_set_drvdata(hdev, drv_data);
 
···
 	if (ret)
 		hid_err(hdev, "hw start failed\n");
 
-err:
 	return ret;
 }
 
 static const struct hid_device_id plantronics_devices[] = {
-	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
-					 USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3210_SERIES),
-		.driver_data = PLT_QUIRK_DOUBLE_VOLUME_KEYS },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
-					 USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3220_SERIES),
-		.driver_data = PLT_QUIRK_DOUBLE_VOLUME_KEYS },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
-					 USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3215_SERIES),
-		.driver_data = PLT_QUIRK_DOUBLE_VOLUME_KEYS },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
-					 USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3225_SERIES),
-		.driver_data = PLT_QUIRK_DOUBLE_VOLUME_KEYS },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
-					 USB_DEVICE_ID_PLANTRONICS_BLACKWIRE_3325_SERIES),
-		.driver_data = PLT_QUIRK_FOLLOWED_OPPOSITE_VOLUME_KEYS },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS,
-					 USB_DEVICE_ID_PLANTRONICS_ENCOREPRO_500_SERIES),
-		.driver_data = PLT_QUIRK_FOLLOWED_OPPOSITE_VOLUME_KEYS },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS, HID_ANY_ID) },
 	{ }
 };
···
 static const struct hid_usage_id plantronics_usages[] = {
 	{ HID_CP_VOLUMEUP, EV_KEY, HID_ANY_ID },
 	{ HID_CP_VOLUMEDOWN, EV_KEY, HID_ANY_ID },
+	{ HID_TELEPHONY_MUTE, EV_KEY, HID_ANY_ID },
+	{ HID_CONSUMER_MUTE, EV_KEY, HID_ANY_ID },
+	{ PLT2_VOL_UP, EV_KEY, HID_ANY_ID },
+	{ PLT2_VOL_DOWN, EV_KEY, HID_ANY_ID },
+	{ PLT2_MIC_MUTE, EV_KEY, HID_ANY_ID },
+	{ PLT1_VOL_UP, EV_KEY, HID_ANY_ID },
+	{ PLT1_VOL_DOWN, EV_KEY, HID_ANY_ID },
+	{ PLT1_MIC_MUTE, EV_KEY, HID_ANY_ID },
 	{ HID_TERMINATOR, HID_TERMINATOR, HID_TERMINATOR }
 };
 

drivers/hid/hid-quirks.c

···
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_GEYSER1_TP_ONLY) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_2021) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_FINGERPRINT_2021) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
 #endif
 #if IS_ENABLED(CONFIG_HID_APPLEIR)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL) },
···
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL3) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL4) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL5) },
+#endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_BL)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+#endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_KBD)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
 #endif
 #if IS_ENABLED(CONFIG_HID_ASUS)
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD) },
···
 #if IS_ENABLED(CONFIG_HID_PLANTRONICS)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS, HID_ANY_ID) },
 #endif
+#if IS_ENABLED(CONFIG_HID_PLAYSTATION)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_2) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_DONGLE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS5_CONTROLLER) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS5_CONTROLLER) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS5_CONTROLLER_2) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS5_CONTROLLER_2) },
+#endif
 #if IS_ENABLED(CONFIG_HID_PRIMAX)
 	{ HID_USB_DEVICE(USB_VENDOR_ID_PRIMAX, USB_DEVICE_ID_PRIMAX_KEYBOARD) },
 #endif
···
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS3_BDREMOTE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS3_CONTROLLER) },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS3_CONTROLLER) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER) },
-	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_2) },
-	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_2) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_PS4_CONTROLLER_DONGLE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_VAIO_VGX_MOUSE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SONY, USB_DEVICE_ID_SONY_VAIO_VGP_MOUSE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SINO_LITE, USB_DEVICE_ID_SINO_LITE_CONTROLLER) },

drivers/hid/hid-steam.c

···
 	if (steam->gamepad_mode)
 		enable = false;
 
+	mutex_lock(&steam->report_mutex);
 	if (enable) {
-		mutex_lock(&steam->report_mutex);
 		/* enable esc, enter, cursors */
 		steam_send_report_byte(steam, ID_SET_DEFAULT_DIGITAL_MAPPINGS);
 		/* reset settings */
 		steam_send_report_byte(steam, ID_LOAD_DEFAULT_SETTINGS);
-		mutex_unlock(&steam->report_mutex);
 	} else {
-		mutex_lock(&steam->report_mutex);
 		/* disable esc, enter, cursor */
 		steam_send_report_byte(steam, ID_CLEAR_DIGITAL_MAPPINGS);
 
···
 				SETTING_RIGHT_TRACKPAD_CLICK_PRESSURE, 0xFFFF, /* disable haptic click */
 				SETTING_STEAM_WATCHDOG_ENABLE, 0, /* disable watchdog that tests if Steam is active */
 				0);
-			mutex_unlock(&steam->report_mutex);
 		} else {
 			steam_write_settings(steam,
 				SETTING_LEFT_TRACKPAD_MODE, TRACKPAD_NONE, /* disable mouse */
 				SETTING_RIGHT_TRACKPAD_MODE, TRACKPAD_NONE, /* disable mouse */
 				0);
-			mutex_unlock(&steam->report_mutex);
 		}
 	}
+	mutex_unlock(&steam->report_mutex);
 }
 
 static int steam_input_open(struct input_dev *dev)

drivers/hid/hid-universal-pidff.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * HID UNIVERSAL PIDFF
+ * hid-pidff wrapper for PID-enabled devices
+ * Handles device reports, quirks and extends usable button range
+ *
+ * Copyright (c) 2024, 2025 Oleg Makarenko
+ * Copyright (c) 2024, 2025 Tomasz Pakuła
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/input-event-codes.h>
+#include "hid-ids.h"
+#include "usbhid/hid-pidff.h"
+
+#define JOY_RANGE (BTN_DEAD - BTN_JOYSTICK + 1)
+
+/*
+ * Map buttons manually to extend the default joystick button limit
+ */
+static int universal_pidff_input_mapping(struct hid_device *hdev,
+	struct hid_input *hi, struct hid_field *field, struct hid_usage *usage,
+	unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_BUTTON)
+		return 0;
+
+	if (field->application != HID_GD_JOYSTICK)
+		return 0;
+
+	int button = ((usage->hid - 1) & HID_USAGE);
+	int code = button + BTN_JOYSTICK;
+
+	/* Detect the end of JOYSTICK buttons range */
+	if (code > BTN_DEAD)
+		code = button + KEY_NEXT_FAVORITE - JOY_RANGE;
+
+	/*
+	 * Map overflowing buttons to KEY_RESERVED to not ignore
+	 * them and let them still trigger MSC_SCAN
+	 */
+	if (code > KEY_MAX)
+		code = KEY_RESERVED;
+
+	hid_map_usage(hi, usage, bit, max, EV_KEY, code);
+	hid_dbg(hdev, "Button %d: usage %d", button, code);
+	return 1;
+}
+
+/*
+ * Check if the device is PID and initialize it
+ * Add quirks after initialisation
+ */
+static int universal_pidff_probe(struct hid_device *hdev,
+				 const struct hid_device_id *id)
+{
+	int i, error;
+	error = hid_parse(hdev);
+	if (error) {
+		hid_err(hdev, "HID parse failed\n");
+		goto err;
+	}
+
+	error = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
+	if (error) {
+		hid_err(hdev, "HID hw start failed\n");
+		goto err;
+	}
+
+	/* Check if device contains PID usage page */
+	error = 1;
+	for (i = 0; i < hdev->collection_size; i++)
+		if ((hdev->collection[i].usage & HID_USAGE_PAGE) == HID_UP_PID) {
+			error = 0;
+			hid_dbg(hdev, "PID usage page found\n");
+			break;
+		}
+
+	/*
+	 * Do not fail as this might be the second "device"
+	 * just for additional buttons/axes. Exit cleanly if force
+	 * feedback usage page wasn't found (included devices were
+	 * tested and confirmed to be USB PID after all).
+	 */
+	if (error) {
+		hid_dbg(hdev, "PID usage page not found in the descriptor\n");
+		return 0;
+	}
+
+	/* Check if HID_PID support is enabled */
+	int (*init_function)(struct hid_device *, u32);
+	init_function = hid_pidff_init_with_quirks;
+
+	if (!init_function) {
+		hid_warn(hdev, "HID_PID support not enabled!\n");
+		return 0;
+	}
+
+	error = init_function(hdev, id->driver_data);
+	if (error) {
+		hid_warn(hdev, "Error initialising force feedback\n");
+		goto err;
+	}
+
+	hid_info(hdev, "Universal pidff driver loaded successfully!");
+
+	return 0;
+err:
+	return error;
+}
+
+static int universal_pidff_input_configured(struct hid_device *hdev,
+					    struct hid_input *hidinput)
+{
+	int axis;
+	struct input_dev *input = hidinput->input;
+
+	if (!input->absinfo)
+		return 0;
+
+	/* Decrease fuzz and deadzone on available axes */
+	for (axis = ABS_X; axis <= ABS_BRAKE; axis++) {
+		if (!test_bit(axis, input->absbit))
+			continue;
+
+		input_set_abs_params(input, axis,
+			input->absinfo[axis].minimum,
+			input->absinfo[axis].maximum,
+			axis == ABS_X ? 0 : 8, 0);
+	}
+
+	/* Remove fuzz and deadzone from the second joystick axis */
+	if (hdev->vendor == USB_VENDOR_ID_FFBEAST &&
+	    hdev->product == USB_DEVICE_ID_FFBEAST_JOYSTICK)
+		input_set_abs_params(input, ABS_Y,
+			input->absinfo[ABS_Y].minimum,
+			input->absinfo[ABS_Y].maximum, 0, 0);
+
+	return 0;
+}
+
+static const struct hid_device_id universal_pidff_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R3),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R3_2),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R5),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R5_2),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R9),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R9_2),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R12),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R12_2),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R16_R21),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_MOZA, USB_DEVICE_ID_MOZA_R16_R21_2),
+		.driver_data = HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CAMMUS, USB_DEVICE_ID_CAMMUS_C5) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CAMMUS, USB_DEVICE_ID_CAMMUS_C12) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_VRS, USB_DEVICE_ID_VRS_DFP),
+		.driver_data = HID_PIDFF_QUIRK_PERMISSIVE_CONTROL },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_FFBEAST, USB_DEVICE_ID_FFBEAST_JOYSTICK), },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_FFBEAST, USB_DEVICE_ID_FFBEAST_RUDDER), },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_FFBEAST, USB_DEVICE_ID_FFBEAST_WHEEL) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LITE_STAR, USB_DEVICE_ID_PXN_V10),
+		.driver_data = HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LITE_STAR, USB_DEVICE_ID_PXN_V12),
+		.driver_data = HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LITE_STAR, USB_DEVICE_ID_PXN_V12_LITE),
+		.driver_data = HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LITE_STAR, USB_DEVICE_ID_PXN_V12_LITE_2),
+		.driver_data = HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LITE_STAR, USB_DEVICE_LITE_STAR_GT987_FF),
+		.driver_data = HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ASETEK, USB_DEVICE_ID_ASETEK_INVICTA) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ASETEK, USB_DEVICE_ID_ASETEK_FORTE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ASETEK, USB_DEVICE_ID_ASETEK_LA_PRIMA) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ASETEK, USB_DEVICE_ID_ASETEK_TONY_KANAAN) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, universal_pidff_devices);
+
+static struct hid_driver universal_pidff = {
+	.name = "hid-universal-pidff",
+	.id_table = universal_pidff_devices,
+	.input_mapping = universal_pidff_input_mapping,
+	.probe = universal_pidff_probe,
+	.input_configured = universal_pidff_input_configured
+};
+module_hid_driver(universal_pidff);
+
+MODULE_DESCRIPTION("Universal driver for USB PID Force Feedback devices");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Oleg Makarenko <[e-mail]>");
+MODULE_AUTHOR("Tomasz Pakuła <[e-mail]>");

drivers/hid/intel-thc-hid/intel-quicki2c/pci-quicki2c.c

···
 
 	pci_set_master(pdev);
 
-	ret = pcim_iomap_regions(pdev, BIT(0), KBUILD_MODNAME);
+	mem_addr = pcim_iomap_region(pdev, 0, KBUILD_MODNAME);
+	ret = PTR_ERR_OR_ZERO(mem_addr);
 	if (ret) {
 		dev_err_once(&pdev->dev, "Failed to get PCI regions, ret = %d.\n", ret);
 		goto disable_pci_device;
 	}
-
-	mem_addr = pcim_iomap_table(pdev)[0];
 
 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (ret) {
 		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 		if (ret) {
 			dev_err_once(&pdev->dev, "No usable DMA configuration %d\n", ret);
-			goto unmap_io_region;
+			goto disable_pci_device;
 		}
 	}
 
···
 	if (ret < 0) {
 		dev_err_once(&pdev->dev,
 			     "Failed to allocate IRQ vectors. ret = %d\n", ret);
-		goto unmap_io_region;
+		goto disable_pci_device;
 	}
 
 	pdev->irq = pci_irq_vector(pdev, 0);
···
 	if (IS_ERR(qcdev)) {
 		dev_err_once(&pdev->dev, "QuickI2C device init failed\n");
 		ret = PTR_ERR(qcdev);
-		goto unmap_io_region;
+		goto disable_pci_device;
 	}
 
 	pci_set_drvdata(pdev, qcdev);
···
 	quicki2c_dma_deinit(qcdev);
 dev_deinit:
 	quicki2c_dev_deinit(qcdev);
-unmap_io_region:
-	pcim_iounmap_regions(pdev, BIT(0));
 disable_pci_device:
 	pci_clear_master(pdev);
 
···
 
 	quicki2c_dev_deinit(qcdev);
 
-	pcim_iounmap_regions(pdev, BIT(0));
 	pci_clear_master(pdev);
 }
 

drivers/hid/intel-thc-hid/intel-quickspi/pci-quickspi.c

···
 
 	thc_interrupt_enable(qsdev->thc_hw, true);
 
-	qsdev->state = QUICKSPI_INITED;
+	qsdev->state = QUICKSPI_INITIATED;
 
 	return qsdev;
 }
···
 
 	pci_set_master(pdev);
 
-	ret = pcim_iomap_regions(pdev, BIT(0), KBUILD_MODNAME);
+	mem_addr = pcim_iomap_region(pdev, 0, KBUILD_MODNAME);
+	ret = PTR_ERR_OR_ZERO(mem_addr);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to get PCI regions, ret = %d.\n", ret);
 		goto disable_pci_device;
 	}
-
-	mem_addr = pcim_iomap_table(pdev)[0];
 
 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (ret) {
 		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 		if (ret) {
 			dev_err(&pdev->dev, "No usable DMA configuration %d\n", ret);
-			goto unmap_io_region;
+			goto disable_pci_device;
 		}
 	}
 
···
 	if (ret < 0) {
 		dev_err(&pdev->dev,
 			"Failed to allocate IRQ vectors. ret = %d\n", ret);
-		goto unmap_io_region;
+		goto disable_pci_device;
 	}
 
 	pdev->irq = pci_irq_vector(pdev, 0);
···
 	if (IS_ERR(qsdev)) {
 		dev_err(&pdev->dev, "QuickSPI device init failed\n");
 		ret = PTR_ERR(qsdev);
-		goto unmap_io_region;
+		goto disable_pci_device;
 	}
 
 	pci_set_drvdata(pdev, qsdev);
···
 	quickspi_dma_deinit(qsdev);
 dev_deinit:
 	quickspi_dev_deinit(qsdev);
-unmap_io_region:
-	pcim_iounmap_regions(pdev, BIT(0));
 disable_pci_device:
 	pci_clear_master(pdev);
 
···
 
 	quickspi_dev_deinit(qsdev);
 
-	pcim_iounmap_regions(pdev, BIT(0));
 	pci_clear_master(pdev);
 }
 

drivers/hid/intel-thc-hid/intel-quickspi/quickspi-dev.h

···
 
 enum quickspi_dev_state {
 	QUICKSPI_NONE,
+	QUICKSPI_INITIATED,
 	QUICKSPI_RESETING,
-	QUICKSPI_RESETED,
-	QUICKSPI_INITED,
+	QUICKSPI_RESET,
 	QUICKSPI_ENABLED,
 	QUICKSPI_DISABLED,
 };

drivers/hid/intel-thc-hid/intel-quickspi/quickspi-protocol.c

···
 		return -EINVAL;
 	}
 
-	qsdev->state = QUICKSPI_RESETED;
+	qsdev->state = QUICKSPI_RESET;
 
 	ret = quickspi_get_device_descriptor(qsdev);
 	if (ret)

drivers/hid/intel-thc-hid/intel-thc/intel-thc-dma.c

···
 		return;
 
 	for (i = 0; i < config->prd_tbl_num; i++) {
-		if (!config->sgls[i] | !config->sgls_nent[i])
+		if (!config->sgls[i] || !config->sgls_nent[i])
 			continue;
 
 		dma_unmap_sg(dev->dev, config->sgls[i],

drivers/hid/usbhid/hid-core.c

···
 #include <linux/hid-debug.h>
 #include <linux/hidraw.h>
 #include "usbhid.h"
+#include "hid-pidff.h"
 
 /*
  * Version Information

drivers/hid/usbhid/hid-pidff.c

···
  *  Force feedback driver for USB HID PID compliant devices
  *
  *  Copyright (c) 2005, 2006 Anssi Hannula <[e-mail]>
+ *  Upgraded 2025 by Oleg Makarenko and Tomasz Pakuła
  */
-
-/*
- */
-
-/* #define DEBUG */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include "hid-pidff.h"
 #include <linux/input.h>
 #include <linux/slab.h>
 #include <linux/usb.h>
-
 #include <linux/hid.h>
+#include <linux/minmax.h>
 
-#include "usbhid.h"
 
 #define	PID_EFFECTS_MAX		64
+#define	PID_INFINITE		U16_MAX
+
+/* Linux Force Feedback API uses miliseconds as time unit */
+#define FF_TIME_EXPONENT	-3
+#define FF_INFINITE		0
 
 /* Report usage table used to put reports into an array */
-
 #define PID_SET_EFFECT		0
 #define PID_EFFECT_OPERATION	1
 #define PID_DEVICE_GAIN		2
···
 	0x21, 0x77, 0x7d, 0x7f, 0x89, 0x90, 0x96, 0xab,
 	0x5a, 0x5f, 0x6e, 0x73, 0x74
 };
+/*
+ * device_control is really 0x95, but 0x96 specified
+ * as it is the usage of the only field in that report.
+ */
 
-/* device_control is really 0x95, but 0x96 specified as it is the usage of
-the only field in that report */
+/* PID special fields */
+#define PID_EFFECT_TYPE			0x25
+#define PID_DIRECTION			0x57
+#define PID_EFFECT_OPERATION_ARRAY	0x78
+#define PID_BLOCK_LOAD_STATUS		0x8b
+#define PID_DEVICE_CONTROL_ARRAY	0x96
 
 /* Value usage tables used to put fields and values into arrays */
-
 #define PID_EFFECT_BLOCK_INDEX	0
 
 #define PID_DURATION		1
···
 static const u8 pidff_pool[] = { 0x80, 0x83, 0xa9 };
 
 /* Special field key tables used to put special field keys into arrays */
-
 #define PID_ENABLE_ACTUATORS	0
-#define PID_RESET		1
-static const u8 pidff_device_control[] = { 0x97, 0x9a };
+#define PID_DISABLE_ACTUATORS	1
+#define PID_STOP_ALL_EFFECTS	2
+#define PID_RESET		3
+#define PID_PAUSE		4
+#define PID_CONTINUE		5
+static const u8 pidff_device_control[] = { 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c };
 
 #define PID_CONSTANT	0
 #define PID_RAMP	1
···
 
 #define PID_BLOCK_LOAD_SUCCESS	0
 #define PID_BLOCK_LOAD_FULL	1
-static const u8 pidff_block_load_status[] = { 0x8c, 0x8d };
+#define PID_BLOCK_LOAD_ERROR	2
+static const u8 pidff_block_load_status[] = { 0x8c, 0x8d, 0x8e};
 
 #define PID_EFFECT_START	0
 #define PID_EFFECT_STOP		1
 static const u8 pidff_effect_operation_status[] = { 0x79, 0x7b };
+
+/* Polar direction 90 degrees (East) */
+#define PIDFF_FIXED_WHEEL_DIRECTION	0x4000
 
 struct pidff_usage {
 	struct hid_field *field;
···
 	struct pidff_usage effect_operation[sizeof(pidff_effect_operation)];
 	struct pidff_usage block_free[sizeof(pidff_block_free)];
 
-	/* Special field is a field that is not composed of
-	   usage<->value pairs that pidff_usage values are */
+	/*
+	 * Special field is a field that is not composed of
+	 * usage<->value pairs that pidff_usage values are
+	 */
 
 	/* Special field in create_new_effect */
 	struct hid_field *create_new_effect_type;
···
 	int operation_id[sizeof(pidff_effect_operation_status)];
 
 	int pid_id[PID_EFFECTS_MAX];
+
+	u32 quirks;
+	u8 effect_count;
 };
+
+/*
+ * Clamp value for a given field
+ */
+static s32 pidff_clamp(s32 i, struct hid_field *field)
+{
+	s32 clamped = clamp(i, field->logical_minimum, field->logical_maximum);
+	pr_debug("clamped from %d to %d", i, clamped);
+	return clamped;
+}
 
 /*
  * Scale an unsigned value with range 0..max for the given field
···
 static int pidff_rescale(int i, int max, struct hid_field *field)
 {
 	return i * (field->logical_maximum - field->logical_minimum) / max +
-	    field->logical_minimum;
+		field->logical_minimum;
 }
 
 /*
- * Scale a signed value in range -0x8000..0x7fff for the given field
+ * Scale a signed value in range S16_MIN..S16_MAX for the given field
  */
 static int pidff_rescale_signed(int i, struct hid_field *field)
 {
-	return i == 0 ? 0 : i >
-	    0 ? i * field->logical_maximum / 0x7fff : i *
-	    field->logical_minimum / -0x8000;
+	if (i > 0) return i * field->logical_maximum / S16_MAX;
+	if (i < 0) return i * field->logical_minimum / S16_MIN;
+	return 0;
+}
+
+/*
+ * Scale time value from Linux default (ms) to field units
+ */
+static u32 pidff_rescale_time(u16 time, struct hid_field *field)
+{
+	u32 scaled_time = time;
+	int exponent = field->unit_exponent;
+	pr_debug("time field exponent: %d\n", exponent);
+
+	for (;exponent < FF_TIME_EXPONENT; exponent++)
+		scaled_time *= 10;
+	for (;exponent > FF_TIME_EXPONENT; exponent--)
+		scaled_time /= 10;
+
+	pr_debug("time calculated from %d to %d\n", time, scaled_time);
+	return scaled_time;
 }
 
 static void pidff_set(struct pidff_usage *usage, u16 value)
 {
-	usage->value[0] = pidff_rescale(value, 0xffff, usage->field);
+	usage->value[0] = pidff_rescale(value, U16_MAX, usage->field);
 	pr_debug("calculated from %d to %d\n", value, usage->value[0]);
 }
 
···
 	else {
 		if (value < 0)
 			usage->value[0] =
-			    pidff_rescale(-value, 0x8000, usage->field);
+			    pidff_rescale(-value, -S16_MIN, usage->field);
 		else
 			usage->value[0] =
-			    pidff_rescale(value, 0x7fff, usage->field);
+			    pidff_rescale(value, S16_MAX, usage->field);
 	}
 	pr_debug("calculated from %d to %d\n", value, usage->value[0]);
+}
+
+static void pidff_set_time(struct pidff_usage *usage, u16 time)
+{
+	u32 modified_time = pidff_rescale_time(time, usage->field);
+	usage->value[0] = pidff_clamp(modified_time, usage->field);
+}
+
+static void pidff_set_duration(struct pidff_usage *usage, u16 duration)
+{
+	/* Infinite value conversion from Linux API -> PID */
+	if (duration == FF_INFINITE)
+		duration = PID_INFINITE;
+
+	/* PID defines INFINITE as the max possible value for duration field */
+	if (duration == PID_INFINITE) {
+		usage->value[0] = (1U << usage->field->report_size) - 1;
+		return;
+	}
+
+	pidff_set_time(usage, duration);
 }
 
 /*
···
 				      struct ff_envelope *envelope)
 {
 	pidff->set_envelope[PID_EFFECT_BLOCK_INDEX].value[0] =
-	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
+		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
 
 	pidff->set_envelope[PID_ATTACK_LEVEL].value[0] =
-	    pidff_rescale(envelope->attack_level >
-			  0x7fff ? 0x7fff : envelope->attack_level, 0x7fff,
-			  pidff->set_envelope[PID_ATTACK_LEVEL].field);
+		pidff_rescale(envelope->attack_level >
+			S16_MAX ? S16_MAX : envelope->attack_level, S16_MAX,
+			pidff->set_envelope[PID_ATTACK_LEVEL].field);
 	pidff->set_envelope[PID_FADE_LEVEL].value[0] =
-	    pidff_rescale(envelope->fade_level >
-			  0x7fff ? 0x7fff : envelope->fade_level, 0x7fff,
-			  pidff->set_envelope[PID_FADE_LEVEL].field);
+		pidff_rescale(envelope->fade_level >
+			S16_MAX ? S16_MAX : envelope->fade_level, S16_MAX,
+			pidff->set_envelope[PID_FADE_LEVEL].field);
 
-	pidff->set_envelope[PID_ATTACK_TIME].value[0] = envelope->attack_length;
-	pidff->set_envelope[PID_FADE_TIME].value[0] = envelope->fade_length;
+	pidff_set_time(&pidff->set_envelope[PID_ATTACK_TIME],
+			envelope->attack_length);
+	pidff_set_time(&pidff->set_envelope[PID_FADE_TIME],
+			envelope->fade_length);
 
 	hid_dbg(pidff->hid, "attack %u => %d\n",
 		envelope->attack_level,
···
 static int pidff_needs_set_envelope(struct ff_envelope *envelope,
 				    struct ff_envelope *old)
 {
-	return envelope->attack_level != old->attack_level ||
-	       envelope->fade_level != old->fade_level ||
+	bool needs_new_envelope;
+	needs_new_envelope = envelope->attack_level  != 0 ||
+			     envelope->fade_level    != 0 ||
+			     envelope->attack_length != 0 ||
+			     envelope->fade_length   != 0;
+
+	if (!needs_new_envelope)
+		return false;
+
+	if (!old)
+		return needs_new_envelope;
+
+	return envelope->attack_level  != old->attack_level  ||
+	       envelope->fade_level    != old->fade_level    ||
 	       envelope->attack_length != old->attack_length ||
-	       envelope->fade_length != old->fade_length;
+	       envelope->fade_length   != old->fade_length;
 }
 
 /*
···
 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
 	pidff->set_effect_type->value[0] =
 		pidff->create_new_effect_type->value[0];
-	pidff->set_effect[PID_DURATION].value[0] = effect->replay.length;
+
+	pidff_set_duration(&pidff->set_effect[PID_DURATION],
+		effect->replay.length);
+
 	pidff->set_effect[PID_TRIGGER_BUTTON].value[0] = effect->trigger.button;
-	pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] =
-		effect->trigger.interval;
+	pidff_set_time(&pidff->set_effect[PID_TRIGGER_REPEAT_INT],
+			effect->trigger.interval);
 	pidff->set_effect[PID_GAIN].value[0] =
 		pidff->set_effect[PID_GAIN].field->logical_maximum;
 	pidff->set_effect[PID_DIRECTION_ENABLE].value[0] = 1;
-	pidff->effect_direction->value[0] =
-		pidff_rescale(effect->direction, 0xffff,
-				pidff->effect_direction);
-	pidff->set_effect[PID_START_DELAY].value[0] = effect->replay.delay;
+
+	/* Use fixed direction if needed */
+	pidff->effect_direction->value[0] = pidff_rescale(
+		pidff->quirks & HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION ?
+		PIDFF_FIXED_WHEEL_DIRECTION : effect->direction,
+		U16_MAX, pidff->effect_direction);
+
+	/* Omit setting delay field if it's missing */
+	if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_DELAY))
+		pidff_set_time(&pidff->set_effect[PID_START_DELAY],
+				effect->replay.delay);
 
 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_EFFECT],
 			HID_REQ_SET_REPORT);
···
 	pidff_set_signed(&pidff->set_periodic[PID_OFFSET],
 			 effect->u.periodic.offset);
 	pidff_set(&pidff->set_periodic[PID_PHASE], effect->u.periodic.phase);
-	pidff->set_periodic[PID_PERIOD].value[0] = effect->u.periodic.period;
+	pidff_set_time(&pidff->set_periodic[PID_PERIOD],
+			effect->u.periodic.period);
 
 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_PERIODIC],
 			HID_REQ_SET_REPORT);
-
 }
 
 /*
···
 static void pidff_set_condition_report(struct pidff_device *pidff,
 				       struct ff_effect *effect)
 {
-	int i;
+	int i, max_axis;
+
+	/* Devices missing Parameter Block Offset can only have one axis */
+	max_axis = pidff->quirks & HID_PIDFF_QUIRK_MISSING_PBO ? 1 : 2;
 
 	pidff->set_condition[PID_EFFECT_BLOCK_INDEX].value[0] =
 		pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0];
 
-	for (i = 0; i < 2; i++) {
-		pidff->set_condition[PID_PARAM_BLOCK_OFFSET].value[0] = i;
+	for (i = 0; i < max_axis; i++) {
+		/* Omit Parameter Block Offset if missing */
+		if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_PBO))
+			pidff->set_condition[PID_PARAM_BLOCK_OFFSET].value[0] = i;
+
 		pidff_set_signed(&pidff->set_condition[PID_CP_OFFSET],
 				 effect->u.condition[i].center);
 		pidff_set_signed(&pidff->set_condition[PID_POS_COEFFICIENT],
···
 }
 
 /*
+ * Set device gain
+ */
+static void pidff_set_gain_report(struct pidff_device *pidff, u16 gain)
+{
+	if (!pidff->device_gain[PID_DEVICE_GAIN_FIELD].field)
+		return;
+
+	pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], gain);
+	hid_hw_request(pidff->hid, pidff->reports[PID_DEVICE_GAIN],
+			HID_REQ_SET_REPORT);
+}
+
+/*
+ * Send device control report to the device
+ */
+static void pidff_set_device_control(struct pidff_device *pidff, int field)
+{
+	int i, index;
+	int field_index = pidff->control_id[field];
+
+	if (field_index < 1)
+		return;
+
+	/* Detect if the field is a bitmask variable or an array */
+	if (pidff->device_control->flags & HID_MAIN_ITEM_VARIABLE) {
+		hid_dbg(pidff->hid, "DEVICE_CONTROL is a bitmask\n");
+
+		/* Clear current bitmask */
+		for(i = 0; i < sizeof(pidff_device_control); i++) {
+			index = pidff->control_id[i];
+			if (index < 1)
+				continue;
+
+			pidff->device_control->value[index - 1] = 0;
+		}
+
+		pidff->device_control->value[field_index - 1] = 1;
+	} else {
+		hid_dbg(pidff->hid, "DEVICE_CONTROL is an array\n");
+		pidff->device_control->value[0] = field_index;
+	}
+
+	hid_hw_request(pidff->hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
+	hid_hw_wait(pidff->hid);
+}
+
+/*
+ * Modify actuators state
+ */
+static void pidff_set_actuators(struct pidff_device *pidff, bool enable)
+{
+	hid_dbg(pidff->hid, "%s actuators\n", enable ? "Enable" : "Disable");
+	pidff_set_device_control(pidff,
+		enable ? PID_ENABLE_ACTUATORS : PID_DISABLE_ACTUATORS);
+}
+
+/*
+ * Reset the device, stop all effects, enable actuators
+ */
+static void pidff_reset(struct pidff_device *pidff)
+{
+	/* We reset twice as sometimes hid_wait_io isn't waiting long enough */
+	pidff_set_device_control(pidff, PID_RESET);
+	pidff_set_device_control(pidff, PID_RESET);
+	pidff->effect_count = 0;
+
+	pidff_set_device_control(pidff, PID_STOP_ALL_EFFECTS);
+	pidff_set_actuators(pidff, 1);
+}
+
+/*
+ * Fetch pool report
+ */
+static void pidff_fetch_pool(struct pidff_device *pidff)
+{
+	int i;
+	struct hid_device *hid = pidff->hid;
+
+	/* Repeat if PID_SIMULTANEOUS_MAX < 2 to make sure it's correct */
+	for(i = 0; i < 20; i++) {
+		hid_hw_request(hid, pidff->reports[PID_POOL], HID_REQ_GET_REPORT);
+		hid_hw_wait(hid);
+
+		if (!pidff->pool[PID_SIMULTANEOUS_MAX].value)
+			return;
+		if (pidff->pool[PID_SIMULTANEOUS_MAX].value[0] >= 2)
+			return;
+	}
+	hid_warn(hid, "device reports %d simultaneous effects\n",
+		 pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
+}
+
+/*
  * Send a request for effect upload to the device
+ *
+ * Reset and enable actuators if no effects were present on the device
  *
  * Returns 0 if device reported success, -ENOSPC if the device reported memory
  * is full. Upon unknown response the function will retry for 60 times, if
···
 static int pidff_request_effect_upload(struct pidff_device *pidff, int efnum)
 {
 	int j;
+
+	if (!pidff->effect_count)
+		pidff_reset(pidff);
 
 	pidff->create_new_effect_type->value[0] = efnum;
 	hid_hw_request(pidff->hid, pidff->reports[PID_CREATE_NEW_EFFECT],
···
 			hid_dbg(pidff->hid, "device reported free memory: %d bytes\n",
 				 pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
 				 pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
+
+			pidff->effect_count++;
 			return 0;
 		}
 		if (pidff->block_load_status->value[0] ==
···
 				pidff->block_load[PID_RAM_POOL_AVAILABLE].value ?
 				pidff->block_load[PID_RAM_POOL_AVAILABLE].value[0] : -1);
 			return -ENOSPC;
+		}
+		if (pidff->block_load_status->value[0] ==
+		    pidff->status_id[PID_BLOCK_LOAD_ERROR]) {
+			hid_dbg(pidff->hid, "device error during effect creation\n");
+			return -EREMOTEIO;
 		}
 	}
 	hid_err(pidff->hid, "pid_block_load failed 60 times\n");
···
 	} else {
 		pidff->effect_operation_status->value[0] =
 			pidff->operation_id[PID_EFFECT_START];
-		pidff->effect_operation[PID_LOOP_COUNT].value[0] = n;
+		pidff->effect_operation[PID_LOOP_COUNT].value[0] =
+			pidff_clamp(n, pidff->effect_operation[PID_LOOP_COUNT].field);
 	}
 
 	hid_hw_request(pidff->hid, pidff->reports[PID_EFFECT_OPERATION],
···
 static int pidff_playback(struct input_dev *dev, int effect_id, int value)
 {
 	struct pidff_device *pidff = dev->ff->private;
-
 	pidff_playback_pid(pidff, pidff->pid_id[effect_id], value);
-
 	return 0;
 }
 
 /*
  * Erase effect with PID id
+ * Decrease the device effect counter
  */
 static void pidff_erase_pid(struct pidff_device *pidff, int pid_id)
 {
 	pidff->block_free[PID_EFFECT_BLOCK_INDEX].value[0] = pid_id;
 	hid_hw_request(pidff->hid, pidff->reports[PID_BLOCK_FREE],
 			HID_REQ_SET_REPORT);
+
+	if (pidff->effect_count > 0)
+		pidff->effect_count--;
 }
 
 /*
···
 
 	hid_dbg(pidff->hid, "starting to erase %d/%d\n",
 		effect_id, pidff->pid_id[effect_id]);
-	/* Wait for the queue to clear. We do not want a full fifo to
-	   prevent the effect removal. */
+
+	/*
+	 * Wait for the queue to clear. We do not want
+	 * a full fifo to prevent the effect removal.
+	 */
 	hid_hw_wait(pidff->hid);
 	pidff_playback_pid(pidff, pid_id, 0);
 	pidff_erase_pid(pidff, pid_id);
···
 			pidff_set_effect_report(pidff, effect);
 		if (!old || pidff_needs_set_constant(effect, old))
 			pidff_set_constant_force_report(pidff, effect);
-		if (!old ||
-		    pidff_needs_set_envelope(&effect->u.constant.envelope,
-					&old->u.constant.envelope))
-			pidff_set_envelope_report(pidff,
-					&effect->u.constant.envelope);
+		if (pidff_needs_set_envelope(&effect->u.constant.envelope,
+					old ? &old->u.constant.envelope : NULL))
+			pidff_set_envelope_report(pidff, &effect->u.constant.envelope);
 		break;
 
 	case FF_PERIODIC:
···
 				return -EINVAL;
 			}
 
+			if (pidff->quirks & HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY)
+				type_id = PID_SINE;
+
 			error = pidff_request_effect_upload(pidff,
 					pidff->type_id[type_id]);
 			if (error)
···
 			pidff_set_effect_report(pidff, effect);
 		if (!old || pidff_needs_set_periodic(effect, old))
 			pidff_set_periodic_report(pidff, effect);
-		if (!old ||
-		    pidff_needs_set_envelope(&effect->u.periodic.envelope,
-					&old->u.periodic.envelope))
-			pidff_set_envelope_report(pidff,
-					&effect->u.periodic.envelope);
+		if (pidff_needs_set_envelope(&effect->u.periodic.envelope,
+					old ? &old->u.periodic.envelope : NULL))
+			pidff_set_envelope_report(pidff, &effect->u.periodic.envelope);
 		break;
 
 	case FF_RAMP:
···
 			pidff_set_effect_report(pidff, effect);
 		if (!old || pidff_needs_set_ramp(effect, old))
 			pidff_set_ramp_force_report(pidff, effect);
-		if (!old ||
-		    pidff_needs_set_envelope(&effect->u.ramp.envelope,
-					&old->u.ramp.envelope))
-			pidff_set_envelope_report(pidff,
-					&effect->u.ramp.envelope);
+		if (pidff_needs_set_envelope(&effect->u.ramp.envelope,
+					old ? &old->u.ramp.envelope : NULL))
+			pidff_set_envelope_report(pidff, &effect->u.ramp.envelope);
 		break;
 
 	case FF_SPRING:
-		if (!old) {
-			error = pidff_request_effect_upload(pidff,
-					pidff->type_id[PID_SPRING]);
-			if (error)
-				return error;
-		}
-		if (!old || pidff_needs_set_effect(effect, old))
-			pidff_set_effect_report(pidff, effect);
-		if (!old || pidff_needs_set_condition(effect, old))
-			pidff_set_condition_report(pidff, effect);
-		break;
-
+	case FF_DAMPER:
+	case FF_INERTIA:
 	case FF_FRICTION:
 		if (!old) {
+			switch(effect->type) {
+			case FF_SPRING:
+				type_id = PID_SPRING;
+				break;
+			case FF_DAMPER:
+				type_id = PID_DAMPER;
+				break;
+			case FF_INERTIA:
+				type_id = PID_INERTIA;
+				break;
+			case FF_FRICTION:
+				type_id = PID_FRICTION;
+				break;
+			}
 			error = pidff_request_effect_upload(pidff,
-					pidff->type_id[PID_FRICTION]);
-			if (error)
-				return error;
-		}
-		if (!old || pidff_needs_set_effect(effect, old))
-			pidff_set_effect_report(pidff, effect);
-		if (!old || pidff_needs_set_condition(effect, old))
-			pidff_set_condition_report(pidff, effect);
-		break;
-
-	case FF_DAMPER:
-		if (!old) {
-			error = pidff_request_effect_upload(pidff,
-					pidff->type_id[PID_DAMPER]);
-			if (error)
-				return error;
-		}
-		if (!old || pidff_needs_set_effect(effect, old))
-			pidff_set_effect_report(pidff, effect);
-		if (!old || pidff_needs_set_condition(effect, old))
-			pidff_set_condition_report(pidff, effect);
-		break;
-
-	case FF_INERTIA:
-		if (!old) {
-			error = pidff_request_effect_upload(pidff,
-					pidff->type_id[PID_INERTIA]);
+					pidff->type_id[type_id]);
 			if (error)
 				return error;
 		}
···
  */
 static void pidff_set_gain(struct input_dev *dev, u16 gain)
 {
-	struct pidff_device *pidff = dev->ff->private;
-
-	pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], gain);
-	hid_hw_request(pidff->hid, pidff->reports[PID_DEVICE_GAIN],
-			HID_REQ_SET_REPORT);
+	pidff_set_gain_report(dev->ff->private, gain);
 }
 
 static void pidff_autocenter(struct pidff_device *pidff, u16 magnitude)
···
 	pidff->set_effect[PID_TRIGGER_REPEAT_INT].value[0] = 0;
 	pidff_set(&pidff->set_effect[PID_GAIN], magnitude);
 	pidff->set_effect[PID_DIRECTION_ENABLE].value[0] = 1;
-	pidff->set_effect[PID_START_DELAY].value[0] = 0;
+
+	/* Omit setting delay field if it's missing */
+	if (!(pidff->quirks & HID_PIDFF_QUIRK_MISSING_DELAY))
+		pidff->set_effect[PID_START_DELAY].value[0] = 0;
 
 	hid_hw_request(pidff->hid, pidff->reports[PID_SET_EFFECT],
 			HID_REQ_SET_REPORT);
···
  */
 static void pidff_set_autocenter(struct input_dev *dev, u16 magnitude)
 {
-	struct pidff_device *pidff = dev->ff->private;
-
-	pidff_autocenter(pidff, magnitude);
+	pidff_autocenter(dev->ff->private, magnitude);
 }
 
 /*
···
 static int pidff_find_fields(struct pidff_usage *usage, const u8 *table,
 			     struct hid_report *report, int count, int strict)
 {
+	if (!report) {
+		pr_debug("pidff_find_fields, null report\n");
+		return -1;
+	}
+
 	int i, j, k, found;
+	int return_value = 0;
 
 	for (k = 0; k < count; k++) {
 		found = 0;
···
 			if (found)
 				break;
 		}
-		if (!found && strict) {
+		if (!found && table[k] == pidff_set_effect[PID_START_DELAY]) {
+			pr_debug("Delay field not found, but that's OK\n");
+			pr_debug("Setting MISSING_DELAY quirk\n");
+			return_value |= HID_PIDFF_QUIRK_MISSING_DELAY;
+		}
+		else if (!found && table[k] == pidff_set_condition[PID_PARAM_BLOCK_OFFSET]) {
+			pr_debug("PBO field not found, but that's OK\n");
+			pr_debug("Setting MISSING_PBO quirk\n");
+			return_value |= HID_PIDFF_QUIRK_MISSING_PBO;
+		}
+		else if (!found && strict) {
 			pr_debug("failed to locate %d\n", k);
 			return -1;
 		}
 	}
-	return 0;
+	return return_value;
 }
 
 /*
···
 static struct hid_field *pidff_find_special_field(struct hid_report *report,
 						  int usage, int enforce_min)
 {
+	if (!report) {
+		pr_debug("pidff_find_special_field, null report\n");
+		return NULL;
+	}
+
 	int i;
 
 	for (i = 0; i < report->maxfield; i++) {
···
 
 	pidff->create_new_effect_type =
 		pidff_find_special_field(pidff->reports[PID_CREATE_NEW_EFFECT],
-					 0x25, 1);
+					 PID_EFFECT_TYPE, 1);
 	pidff->set_effect_type =
 		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
-					 0x25, 1);
+					 PID_EFFECT_TYPE, 1);
 	pidff->effect_direction =
 		pidff_find_special_field(pidff->reports[PID_SET_EFFECT],
-					 0x57, 0);
+					 PID_DIRECTION, 0);
 	pidff->device_control =
 		pidff_find_special_field(pidff->reports[PID_DEVICE_CONTROL],
-					 0x96, 1);
+			PID_DEVICE_CONTROL_ARRAY,
+			!(pidff->quirks & HID_PIDFF_QUIRK_PERMISSIVE_CONTROL));
+
 	pidff->block_load_status =
 		pidff_find_special_field(pidff->reports[PID_BLOCK_LOAD],
-					 0x8b, 1);
+					 PID_BLOCK_LOAD_STATUS, 1);
 	pidff->effect_operation_status =
 		pidff_find_special_field(pidff->reports[PID_EFFECT_OPERATION],
-					 0x78, 1);
+					 PID_EFFECT_OPERATION_ARRAY, 1);
 
 	hid_dbg(pidff->hid, "search done\n");
 
···
 		hid_err(pidff->hid, "effect operation field not found\n");
 		return -1;
 	}
-
-	pidff_find_special_keys(pidff->control_id, pidff->device_control,
-				pidff_device_control,
-				sizeof(pidff_device_control));
 
 	PIDFF_FIND_SPECIAL_KEYS(control_id, device_control, device_control);
 
···
 		set_bit(FF_FRICTION, dev->ffbit);
 
 	return 0;
-
 }
 
 #define PIDFF_FIND_FIELDS(name, report, strict) \
···
  */
 static int pidff_init_fields(struct pidff_device *pidff, struct input_dev *dev)
 {
-	int envelope_ok = 0;
+	int status = 0;
 
-	if (PIDFF_FIND_FIELDS(set_effect, PID_SET_EFFECT, 1)) {
+	/* Save info about the device not having the DELAY ffb field. */
+	status = PIDFF_FIND_FIELDS(set_effect, PID_SET_EFFECT, 1);
+	if (status == -1) {
 		hid_err(pidff->hid, "unknown set_effect report layout\n");
 		return -ENODEV;
 	}
+	pidff->quirks |= status;
+
+	if (status & HID_PIDFF_QUIRK_MISSING_DELAY)
+		hid_dbg(pidff->hid, "Adding MISSING_DELAY quirk\n");
+
 
 	PIDFF_FIND_FIELDS(block_load, PID_BLOCK_LOAD, 0);
 	if (!pidff->block_load[PID_EFFECT_BLOCK_INDEX].value) {
···
 		return -ENODEV;
 	}
 
-	if (!PIDFF_FIND_FIELDS(set_envelope, PID_SET_ENVELOPE, 1))
-		envelope_ok = 1;
-
 	if (pidff_find_special_fields(pidff) || pidff_find_effects(pidff, dev))
 		return -ENODEV;
 
-	if (!envelope_ok) {
+	if (PIDFF_FIND_FIELDS(set_envelope, PID_SET_ENVELOPE, 1)) {
 		if (test_and_clear_bit(FF_CONSTANT, dev->ffbit))
 			hid_warn(pidff->hid,
 				 "has constant effect but no envelope\n");
···
 		clear_bit(FF_RAMP, dev->ffbit);
 	}
 
-	if ((test_bit(FF_SPRING, dev->ffbit) ||
-	     test_bit(FF_DAMPER, dev->ffbit) ||
-	     test_bit(FF_FRICTION, dev->ffbit) ||
-	     test_bit(FF_INERTIA, dev->ffbit)) &&
-	    PIDFF_FIND_FIELDS(set_condition, PID_SET_CONDITION, 1)) {
-		hid_warn(pidff->hid, "unknown condition effect layout\n");
-		clear_bit(FF_SPRING, dev->ffbit);
-		clear_bit(FF_DAMPER, dev->ffbit);
-		clear_bit(FF_FRICTION, dev->ffbit);
-		clear_bit(FF_INERTIA, dev->ffbit);
+	if (test_bit(FF_SPRING, dev->ffbit) ||
+	    test_bit(FF_DAMPER, dev->ffbit) ||
+	    test_bit(FF_FRICTION, dev->ffbit) ||
+	    test_bit(FF_INERTIA, dev->ffbit)) {
+		status = PIDFF_FIND_FIELDS(set_condition, PID_SET_CONDITION, 1);
+
+		if (status < 0) {
+			hid_warn(pidff->hid, "unknown condition effect layout\n");
+			clear_bit(FF_SPRING, dev->ffbit);
+			clear_bit(FF_DAMPER, dev->ffbit);
+			clear_bit(FF_FRICTION, dev->ffbit);
+			clear_bit(FF_INERTIA, dev->ffbit);
+		}
+		pidff->quirks |= status;
 	}
 
 	if (test_bit(FF_PERIODIC, dev->ffbit) &&
···
 		set_bit(FF_GAIN, dev->ffbit);
 
 	return 0;
-}
-
-/*
- * Reset the device
- */
-static void pidff_reset(struct pidff_device *pidff)
-{
-	struct hid_device *hid = pidff->hid;
-	int i = 0;
-
-	pidff->device_control->value[0] = pidff->control_id[PID_RESET];
-	/* We reset twice as sometimes hid_wait_io isn't waiting long enough */
-	hid_hw_request(hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
-	hid_hw_wait(hid);
-	hid_hw_request(hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
-	hid_hw_wait(hid);
-
-	pidff->device_control->value[0] =
-		pidff->control_id[PID_ENABLE_ACTUATORS];
-	hid_hw_request(hid, pidff->reports[PID_DEVICE_CONTROL], HID_REQ_SET_REPORT);
-	hid_hw_wait(hid);
-
-	/* pool report is sometimes messed up, refetch it */
-	hid_hw_request(hid, pidff->reports[PID_POOL], HID_REQ_GET_REPORT);
-	hid_hw_wait(hid);
-
-	if (pidff->pool[PID_SIMULTANEOUS_MAX].value) {
-		while (pidff->pool[PID_SIMULTANEOUS_MAX].value[0] < 2) {
-			if (i++ > 20) {
-				hid_warn(pidff->hid,
-					 "device reports %d simultaneous effects\n",
-					 pidff->pool[PID_SIMULTANEOUS_MAX].value[0]);
-				break;
-			}
-			hid_dbg(pidff->hid, "pid_pool requested again\n");
-			hid_hw_request(hid, pidff->reports[PID_POOL],
-					  HID_REQ_GET_REPORT);
-			hid_hw_wait(hid);
-		}
-	}
 }
 
 /*
···
 
 	if (pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0] ==
 	    pidff->block_load[PID_EFFECT_BLOCK_INDEX].field->logical_minimum + 1) {
-		pidff_autocenter(pidff, 0xffff);
+		pidff_autocenter(pidff, U16_MAX);
 		set_bit(FF_AUTOCENTER, dev->ffbit);
 	} else {
 		hid_notice(pidff->hid,
 			   "device has unknown autocenter control method\n");
 	}
-
 	pidff_erase_pid(pidff,
 			pidff->block_load[PID_EFFECT_BLOCK_INDEX].value[0]);
 
 	return 0;
-
 }
 
 /*
  * Check if the device is PID and initialize it
+ * Set initial quirks
  */
-int hid_pidff_init(struct hid_device *hid)
+int hid_pidff_init_with_quirks(struct hid_device *hid, u32 initial_quirks)
 {
 	struct pidff_device *pidff;
 	struct hid_input *hidinput = list_entry(hid->inputs.next,
···
 		return -ENOMEM;
 
 	pidff->hid = hid;
+	pidff->quirks = initial_quirks;
+	pidff->effect_count = 0;
 
 	hid_device_io_start(hid);
 
···
 	if (error)
 		goto fail;
 
-	pidff_reset(pidff);
-
-	if (test_bit(FF_GAIN, dev->ffbit)) {
-		pidff_set(&pidff->device_gain[PID_DEVICE_GAIN_FIELD], 0xffff);
-		hid_hw_request(hid, pidff->reports[PID_DEVICE_GAIN],
-				     HID_REQ_SET_REPORT);
-	}
-
+	/* pool report is sometimes messed up, refetch it */
+	pidff_fetch_pool(pidff);
+	pidff_set_gain_report(pidff, U16_MAX);
 	error = pidff_check_autocenter(pidff, dev);
 	if (error)
 		goto fail;
···
 	ff->playback = pidff_playback;
 
 	hid_info(dev, "Force feedback for USB HID PID devices by Anssi Hannula <[e-mail]>\n");
+	hid_dbg(dev, "Active quirks mask: 0x%x\n", pidff->quirks);
 
 	hid_device_io_stop(hid);
 
···
 
 	kfree(pidff);
 	return error;
+}
+EXPORT_SYMBOL_GPL(hid_pidff_init_with_quirks);
+
+/*
+ * Check if the device is PID and initialize it
+ * Wrapper made to keep the compatibility with old
+ * init function
+ */
+int hid_pidff_init(struct hid_device *hid)
+{
+	return hid_pidff_init_with_quirks(hid, 0);
 }

drivers/hid/usbhid/hid-pidff.h

···
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __HID_PIDFF_H
+#define __HID_PIDFF_H
+
+#include <linux/hid.h>
+
+/* HID PIDFF quirks */
+
+/* Delay field (0xA7) missing. Skip it during set effect report upload */
+#define HID_PIDFF_QUIRK_MISSING_DELAY		BIT(0)
+
+/* Missing Paramter block offset (0x23). Skip it during SET_CONDITION
+   report upload */
+#define HID_PIDFF_QUIRK_MISSING_PBO		BIT(1)
+
+/* Initialise device control field even if logical_minimum != 1 */
+#define HID_PIDFF_QUIRK_PERMISSIVE_CONTROL	BIT(2)
+
+/* Use fixed 0x4000 direction during SET_EFFECT report upload */
+#define HID_PIDFF_QUIRK_FIX_WHEEL_DIRECTION	BIT(3)
+
+/* Force all periodic effects to be uploaded as SINE */
+#define HID_PIDFF_QUIRK_PERIODIC_SINE_ONLY	BIT(4)
+
+#ifdef CONFIG_HID_PID
+int hid_pidff_init(struct hid_device *hid);
+int hid_pidff_init_with_quirks(struct hid_device *hid, u32 initial_quirks);
+#else
+#define hid_pidff_init NULL
+#define hid_pidff_init_with_quirks NULL
+#endif
+
+#endif

drivers/hid/usbhid/usbkbd.c

···
 		return -1;
 
 	spin_lock_irqsave(&kbd->leds_lock, flags);
-	kbd->newleds = (!!test_bit(LED_KANA,    dev->led) << 3) | (!!test_bit(LED_COMPOSE, dev->led) << 3) |
+	kbd->newleds = (!!test_bit(LED_KANA,    dev->led) << 4) | (!!test_bit(LED_COMPOSE, dev->led) << 3) |
 		       (!!test_bit(LED_SCROLLL, dev->led) << 2) | (!!test_bit(LED_CAPSL,   dev->led) << 1) |
 		       (!!test_bit(LED_NUML,    dev->led));
 

drivers/hid/wacom_sys.c

···
 				  struct kfifo_rec_ptr_2 *fifo)
 {
 	while (!kfifo_is_empty(fifo)) {
-		u8 buf[WACOM_PKGLEN_MAX];
-		int size;
+		int size = kfifo_peek_len(fifo);
+		u8 *buf = kzalloc(size, GFP_KERNEL);
+		unsigned int count;
 		int err;
 
-		size = kfifo_out(fifo, buf, sizeof(buf));
+		count = kfifo_out(fifo, buf, size);
+		if (count != size) {
+			// Hard to say what is the "right" action in this
+			// circumstance. Skipping the entry and continuing
+			// to flush seems reasonable enough, however.
+			hid_warn(hdev, "%s: removed fifo entry with unexpected size\n",
+				 __func__);
+			continue;
+		}
 		err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, false);
 		if (err) {
 			hid_warn(hdev, "%s: unable to flush event due to error %d\n",
 				 __func__, err);
 		}
+
+		kfree(buf);
 	}
 }
 
···
 	if (wacom->wacom_wac.features.type == BOOTLOADER)
 		return 0;
 
-	if (size > WACOM_PKGLEN_MAX)
-		return 1;
-
 	if (wacom_wac_pen_serial_enforce(hdev, report, raw_data, size))
 		return -1;
 
-	memcpy(wacom->wacom_wac.data, raw_data, size);
+	wacom->wacom_wac.data = raw_data;
 
 	wacom_wac_irq(&wacom->wacom_wac, size);
 
···
 static int wacom_devm_kfifo_alloc(struct wacom *wacom)
 {
 	struct wacom_wac *wacom_wac = &wacom->wacom_wac;
+	int fifo_size = min(PAGE_SIZE, 10 * wacom_wac->features.pktlen);
 	struct kfifo_rec_ptr_2 *pen_fifo;
 	int error;
 
···
 	if (!pen_fifo)
 		return -ENOMEM;
 
-	error = kfifo_alloc(pen_fifo, WACOM_PKGLEN_MAX, GFP_KERNEL);
+	error = kfifo_alloc(pen_fifo, fifo_size, GFP_KERNEL);
 	if (error) {
 		devres_free(pen_fifo);
 		return error;
···
 	unsigned int connect_mask = HID_CONNECT_HIDRAW;
 
 	features->pktlen = wacom_compute_pktlen(hdev);
-	if (features->pktlen > WACOM_PKGLEN_MAX)
-		return -EINVAL;
 
 	if (!devres_open_group(&hdev->dev, wacom, GFP_KERNEL))
 		return -ENOMEM;
+
+	error = wacom_devm_kfifo_alloc(wacom);
+	if (error)
+		goto fail;
 
 	wacom->resources = true;
 
···
 
 	if (features->check_for_hid_type && features->hid_type != hdev->type)
 		return -ENODEV;
-
-	error = wacom_devm_kfifo_alloc(wacom);
-	if (error)
-		return error;
 
 	wacom_wac->hid_data.inputmode = -1;
 	wacom_wac->mode_report = -1;

drivers/hid/wacom_wac.c

···
 
 static int wacom_intuos_bt_irq(struct wacom_wac *wacom, size_t len)
 {
-	unsigned char data[WACOM_PKGLEN_MAX];
+	u8 *data = kmemdup(wacom->data, len, GFP_KERNEL);
 	int i = 1;
 	unsigned power_raw, battery_capacity, bat_charging, ps_connected;
-
-	memcpy(data, wacom->data, len);
 
 	switch (data[0]) {
 	case 0x04:
···
 		dev_dbg(wacom->pen_input->dev.parent,
 				"Unknown report: %d,%d size:%zu\n",
 				data[0], data[1], len);
-		return 0;
+		break;
 	}
+
+	kfree(data);
 	return 0;
 }
 

drivers/hid/wacom_wac.h

···
 #include <linux/hid.h>
 #include <linux/kfifo.h>
 
-/* maximum packet length for USB/BT devices */
-#define WACOM_PKGLEN_MAX	361
-
 #define WACOM_NAME_MAX		64
 #define WACOM_MAX_REMOTES	5
 #define WACOM_STATUS_UNKNOWN	255
···
 	unsigned touch_max;
 	int oVid;
 	int oPid;
-	int pktlen;
+	unsigned int pktlen;
 	bool check_for_hid_type;
 	int hid_type;
 };
···
 	char pen_name[WACOM_NAME_MAX];
 	char touch_name[WACOM_NAME_MAX];
 	char pad_name[WACOM_NAME_MAX];
-	unsigned char data[WACOM_PKGLEN_MAX];
+	u8 *data;
 	int tool[2];
 	int id[2];
 	__u64 serial[2];

include/linux/hid.h

···
 #define HID_MAIN_ITEM_TAG_FEATURE		11
 #define HID_MAIN_ITEM_TAG_BEGIN_COLLECTION	10
 #define HID_MAIN_ITEM_TAG_END_COLLECTION	12
+#define HID_MAIN_ITEM_TAG_RESERVED_MIN		13
+#define HID_MAIN_ITEM_TAG_RESERVED_MAX		15
 
 /*
  * HID report descriptor main item contents
···
 unsigned long hid_lookup_quirk(const struct hid_device *hdev);
 int hid_quirks_init(char **quirks_param, __u16 bus, int count);
 void hid_quirks_exit(__u16 bus);
-
-#ifdef CONFIG_HID_PID
-int hid_pidff_init(struct hid_device *hid);
-#else
-#define hid_pidff_init NULL
-#endif
 
 #define dbg_hid(fmt, ...) pr_debug("%s: " fmt, __FILE__, ##__VA_ARGS__)
 

sound/usb/mixer_quirks.c

···
 	}
 }
 
+/*
+ * Some Plantronics headsets have control names that don't meet ALSA naming
+ * standards. This function fixes nonstandard source names. By the time
+ * this function is called the control name should look like one of these:
+ * "source names Playback Volume"
+ * "source names Playback Switch"
+ * "source names Capture Volume"
+ * "source names Capture Switch"
+ * If any of the trigger words are found in the name then the name will
+ * be changed to:
+ * "Headset Playback Volume"
+ * "Headset Playback Switch"
+ * "Headset Capture Volume"
+ * "Headset Capture Switch"
+ * depending on the current suffix.
+ */
+static void snd_fix_plt_name(struct snd_usb_audio *chip,
+			     struct snd_ctl_elem_id *id)
+{
+	/* no variant of "Sidetone" should be added to this list */
+	static const char * const trigger[] = {
+		"Earphone", "Microphone", "Receive", "Transmit"
+	};
+	static const char * const suffix[] = {
+		" Playback Volume", " Playback Switch",
+		" Capture Volume", " Capture Switch"
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(trigger); i++)
+		if (strstr(id->name, trigger[i]))
+			goto triggered;
+	usb_audio_dbg(chip, "no change in %s\n", id->name);
+	return;
+
+triggered:
+	for (i = 0; i < ARRAY_SIZE(suffix); i++)
+		if (strstr(id->name, suffix[i])) {
+			usb_audio_dbg(chip, "fixing kctl name %s\n", id->name);
+			snprintf(id->name, sizeof(id->name), "Headset%s",
+				 suffix[i]);
+			return;
+		}
+	usb_audio_dbg(chip, "something wrong in kctl name %s\n", id->name);
+}
+
 void snd_usb_mixer_fu_apply_quirk(struct usb_mixer_interface *mixer,
 				  struct usb_mixer_elem_info *cval, int unitid,
 				  struct snd_kcontrol *kctl)
···
 			cval->min_mute = 1;
 		break;
 	}
+
+	/* ALSA-ify some Plantronics headset control names */
+	if (USB_ID_VENDOR(mixer->chip->usb_id) == 0x047f &&
+	    (cval->control == UAC_FU_MUTE || cval->control == UAC_FU_VOLUME))
+		snd_fix_plt_name(mixer->chip, &kctl->id);
 }