HID: Add driver to fix Speedlink VAD Cezanne support

Speedlink VAD Cezanne have a hardware bug that makes the cursor "jump" from one
place to another every now and then. The issue are relative motion events
erroneously reported by the device, each having a distance value of +256. This
256 can in fact never occur due to real motion, therefore those events can
safely be ignored. The driver also drops useless EV_REL events with a value of
0, that the device sends every time it sends an "real" EV_REL or EV_KEY event.

Signed-off-by: Stefan Kriwanek <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/hid/Kconfig

···
 	---help---
 	Support for Sony PS3 controller.
 
+config HID_SPEEDLINK
+	tristate "Speedlink VAD Cezanne mouse support"
+	depends on USB_HID
+	---help---
+	Support for Speedlink Vicious and Divine Cezanne mouse.
+
 config HID_SUNPLUS
 	tristate "Sunplus wireless desktop"
 	depends on USB_HID

drivers/hid/Makefile

···
 obj-$(CONFIG_HID_SAMSUNG)	+= hid-samsung.o
 obj-$(CONFIG_HID_SMARTJOYPLUS)	+= hid-sjoy.o
 obj-$(CONFIG_HID_SONY)		+= hid-sony.o
+obj-$(CONFIG_HID_SPEEDLINK)	+= hid-speedlink.o
 obj-$(CONFIG_HID_SUNPLUS)	+= hid-sunplus.o
 obj-$(CONFIG_HID_GREENASIA)	+= hid-gaff.o
 obj-$(CONFIG_HID_THRUSTMASTER)	+= hid-tmff.o

drivers/hid/hid-core.c

···
 	{ HID_USB_DEVICE(USB_VENDOR_ID_WALTOP, USB_DEVICE_ID_WALTOP_SLIM_TABLET_12_1_INCH) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_WALTOP, USB_DEVICE_ID_WALTOP_MEDIA_TABLET_10_6_INCH) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_WALTOP, USB_DEVICE_ID_WALTOP_MEDIA_TABLET_14_1_INCH) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ZEROPLUS, 0x0005) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ZEROPLUS, 0x0030) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ZYDACRON, USB_DEVICE_ID_ZYDACRON_REMOTE_CONTROL) },

drivers/hid/hid-ids.h

···
 #define USB_VENDOR_ID_WISEGROUP_LTD2	0x6677
 #define USB_DEVICE_ID_SMARTJOY_DUAL_PLUS 0x8802
 
+#define USB_VENDOR_ID_X_TENSIONS               0x1ae7
+#define USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE    0x9001
+
 #define USB_VENDOR_ID_YEALINK		0x6993
 #define USB_DEVICE_ID_YEALINK_P1K_P4K_B2K	0xb001
 

drivers/hid/hid-speedlink.c

···
+/*
+ *  HID driver for Speedlink Vicious and Divine Cezanne (USB mouse).
+ *  Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from
+ *  the HID descriptor.
+ *
+ *  Copyright (c) 2011 Stefan Kriwanek <[e-mail]>
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+#include "usbhid/usbhid.h"
+
+static const struct hid_device_id speedlink_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)},
+	{ }
+};
+
+static int speedlink_input_mapping(struct hid_device *hdev,
+		struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	/*
+	 * The Cezanne mouse has a second "keyboard" USB endpoint for it is
+	 * able to map keyboard events to the button presses.
+	 * It sends a standard keyboard report descriptor, though, whose
+	 * LEDs we ignore.
+	 */
+	switch (usage->hid & HID_USAGE_PAGE) {
+	case HID_UP_LED:
+		return -1;
+	}
+	return 0;
+}
+
+static int speedlink_event(struct hid_device *hdev, struct hid_field *field,
+		struct hid_usage *usage, __s32 value)
+{
+	/* No other conditions due to usage_table. */
+	/* Fix "jumpy" cursor (invalid events sent by device). */
+	if (value == 256)
+		return 1;
+	/* Drop useless distance 0 events (on button clicks etc.) as well */
+	if (value == 0)
+		return 1;
+
+	return 0;
+}
+
+MODULE_DEVICE_TABLE(hid, speedlink_devices);
+
+static const struct hid_usage_id speedlink_grabbed_usages[] = {
+	{ HID_GD_X, EV_REL, 0 },
+	{ HID_GD_Y, EV_REL, 1 },
+	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
+};
+
+static struct hid_driver speedlink_driver = {
+	.name = "speedlink",
+	.id_table = speedlink_devices,
+	.usage_table = speedlink_grabbed_usages,
+	.input_mapping = speedlink_input_mapping,
+	.event = speedlink_event,
+};
+
+static int __init speedlink_init(void)
+{
+	return hid_register_driver(&speedlink_driver);
+}
+
+static void __exit speedlink_exit(void)
+{
+	hid_unregister_driver(&speedlink_driver);
+}
+
+module_init(speedlink_init);
+module_exit(speedlink_exit);
+MODULE_LICENSE("GPL");