Merge tag 'for-linus-2023083101' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid

Pull HID updates from Benjamin Tissoires:

- devm fixes for problems that caused use-after-free reports (Rahul
Rameshbabu)

- Some extensive HID docs (Marco Morandini)

- Constification of struct class (Ivan Orlov and Greg Kroah-Hartman)

- Google Stadia Force Feedback support (Fabio Baltieri)

- Various fixes and new device ID support

* tag 'for-linus-2023083101' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (42 commits)
HID: logitech-hidpp: rework one more time the retries attempts
HID: nvidia-shield: Reference hid_device devm allocation of input_dev name
HID: multitouch: Correct devm device reference for hidinput input_dev name
HID: uclogic: Correct devm device reference for hidinput input_dev name
HID: logitech-dj: Fix error handling in logi_dj_recv_switch_to_dj_mode()
HID: i2c-hid: elan: Add ili9882t timing
dt-bindings: input: i2c-hid: Introduce Ilitek ili9882t
HID: apple: Add "Hailuck" to the list of non-apple keyboards
HID: steelseries: arctis_1_battery_request[] should be static
MAINTAINERS: update my email address
HID: logitech-hidpp: Add support for Logitech MX Anywhere 3 mouse
HID: wacom: struct name cleanup
HID: wacom: remove unnecessary 'connected' variable from EKR
HID: wacom: remove the battery when the EKR is off
HID: nvidia-shield: Update Thunderstrike LED instance name to use id
HID: nvidia-shield: Add battery support for Thunderstrike
HID: nvidia-shield: Remove led_classdev_unregister in thunderstrike_create
HID: hid-google-stadiaff: add support for Stadia force feedback
HID: logitech-dj: Add support for a new lightspeed receiver iteration
HID: logitech-hidpp: Add support for the Pro X Superlight
...

.mailmap

···
 Daniel Borkmann <[e-mail]> <[e-mail]>
 David Brownell <[e-mail]>
 David Collins <[e-mail]> <[e-mail]>
+David Rheinsberg <[e-mail]> <[e-mail]>
+David Rheinsberg <[e-mail]> <[e-mail]>
+David Rheinsberg <[e-mail]> <[e-mail]>
 David Woodhouse <[e-mail]>
 Dedy Lansky <[e-mail]> <[e-mail]>
 Deepak Kumar Singh <[e-mail]> <[e-mail]>

Documentation/devicetree/bindings/input/ilitek,ili9882t.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/ilitek,ili9882t.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek ili9882t touchscreen controller
+
+maintainers:
+  - Cong Yang <[e-mail]>
+
+description:
+  Supports the Ilitek ili9882t touchscreen controller.
+  This touchscreen controller uses the i2c-hid protocol with a reset GPIO.
+
+allOf:
+  - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+
+properties:
+  compatible:
+    const: ilitek,ili9882t
+
+  reg:
+    const: 0x41
+
+  interrupts:
+    maxItems: 1
+
+  panel: true
+
+  reset-gpios:
+    maxItems: 1
+    description: Reset GPIO.
+
+  vccio-supply:
+    description: The 1.8V supply to the touchscreen.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - panel
+  - vccio-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      touchscreen: touchscreen@41 {
+        compatible = "ilitek,ili9882t";
+        reg = <0x41>;
+
+        interrupt-parent = <&pio>;
+        interrupts = <12 IRQ_TYPE_LEVEL_LOW>;
+
+        panel = <&panel>;
+        reset-gpios = <&pio 60 GPIO_ACTIVE_LOW>;
+        vccio-supply = <&mt6366_vio18_reg>;
+      };
+    };

Documentation/hid/hidintro.rst

···
+.. SPDX-License-Identifier: GPL-2.0
+
+======================================
+Introduction to HID report descriptors
+======================================
+
+This chapter is meant to give a broad overview of what HID report
+descriptors are, and of how a casual (non-kernel) programmer can deal
+with HID devices that are not working well with Linux.
+
+.. contents::
+    :local:
+    :depth: 2
+
+.. toctree::
+   :maxdepth: 2
+
+   hidreport-parsing
+
+
+Introduction
+============
+
+HID stands for Human Interface Device, and can be whatever device you
+are using to interact with a computer, be it a mouse, a touchpad, a
+tablet, a microphone.
+
+Many HID devices work out the box, even if their hardware is different.
+For example, mice can have any number of buttons; they may have a
+wheel; movement sensitivity differs between different models, and so
+on. Nonetheless, most of the time everything just works, without the
+need to have specialized code in the kernel for every mouse model
+developed since 1970.
+
+This is because modern HID devices do advertise their capabilities
+through the *HID report descriptor*, a fixed set of bytes describing
+exactly what *HID reports* may be sent between the device and the host
+and the meaning of each individual bit in those reports. For example,
+a HID Report Descriptor may specify that "in a report with ID 3 the
+bits from 8 to 15 is the delta x coordinate of a mouse".
+
+The HID report itself then merely carries the actual data values
+without any extra meta information. Note that HID reports may be sent
+from the device ("Input Reports", i.e. input events), to the device
+("Output Reports" to e.g. change LEDs) or used for device configuration
+("Feature reports"). A device may support one or more HID reports.
+
+The HID subsystem is in charge of parsing the HID report descriptors,
+and converts HID events into normal input device interfaces (see
+Documentation/hid/hid-transport.rst). Devices may misbehave because the
+HID report descriptor provided by the device is wrong, or because it
+needs to be dealt with in a special way, or because some special
+device or interaction mode is not handled by the default code.
+
+The format of HID report descriptors is described by two documents,
+available from the `USB Implementers Forum <https://www.usb.org/>`_
+`HID web page <https://www.usb.org/hid>`_ address:
+
+ * the `HID USB Device Class Definition
+   <https://www.usb.org/document-library/device-class-definition-hid-111>`_ (HID Spec from now on)
+ * the `HID Usage Tables <https://usb.org/document-library/hid-usage-tables-14>`_ (HUT from now on)
+
+The HID subsystem can deal with different transport drivers
+(USB, I2C, Bluetooth, etc.). See Documentation/hid/hid-transport.rst.
+
+Parsing HID report descriptors
+==============================
+
+The current list of HID devices can be found at ``/sys/bus/hid/devices/``.
+For each device, say ``/sys/bus/hid/devices/0003\:093A\:2510.0002/``,
+one can read the corresponding report descriptor::
+
+  $ hexdump -C /sys/bus/hid/devices/0003\:093A\:2510.0002/report_descriptor
+  00000000  05 01 09 02 a1 01 09 01  a1 00 05 09 19 01 29 03  |..............).|
+  00000010  15 00 25 01 75 01 95 03  81 02 75 05 95 01 81 01  |..%.u.....u.....|
+  00000020  05 01 09 30 09 31 09 38  15 81 25 7f 75 08 95 03  |...0.1.8..%.u...|
+  00000030  81 06 c0 c0                                       |....|
+  00000034
+
+Optional: the HID report descriptor can be read also by
+directly accessing the hidraw driver [#hidraw]_.
+
+The basic structure of HID report descriptors is defined in the HID
+spec, while HUT "defines constants that can be interpreted by an
+application to identify the purpose and meaning of a data field in a
+HID report". Each entry is defined by at least two bytes, where the
+first one defines what type of value is following and is described in
+the HID spec, while the second one carries the actual value and is
+described in the HUT.
+
+HID report descriptors can, in principle, be painstakingly parsed by
+hand, byte by byte.
+
+A short introduction on how to do this is sketched in
+Documentation/hid/hidreport-parsing.rst; you only need to understand it
+if you need to patch HID report descriptors.
+
+In practice you should not parse HID report descriptors by hand; rather,
+you should use an existing parser. Among all the available ones
+
+  * the online `USB Descriptor and Request Parser
+    <http://eleccelerator.com/usbdescreqparser/>`_;
+  * `hidrdd <https://github.com/abend0c1/hidrdd>`_,
+    that provides very detailed and somewhat verbose descriptions
+    (verbosity can be useful if you are not familiar with HID report
+    descriptors);
+  * `hid-tools <https://gitlab.freedesktop.org/libevdev/hid-tools>`_,
+    a complete utility set that allows, among other things,
+    to record and replay the raw HID reports and to debug
+    and replay HID devices.
+    It is being actively developed by the Linux HID subsystem maintainers.
+
+Parsing the mouse HID report descriptor with `hid-tools
+<https://gitlab.freedesktop.org/libevdev/hid-tools>`_ leads to
+(explanations interposed)::
+
+    $ ./hid-decode /sys/bus/hid/devices/0003\:093A\:2510.0002/report_descriptor
+    # device 0:0
+    # 0x05, 0x01,		     // Usage Page (Generic Desktop)	    0
+    # 0x09, 0x02,		     // Usage (Mouse)			    2
+    # 0xa1, 0x01,		     // Collection (Application)	    4
+    # 0x09, 0x01,		     // Usage (Pointer)		    	    6
+    # 0xa1, 0x00,		     // Collection (Physical)  	    	    8
+    # 0x05, 0x09, 		     //	Usage Page (Button)		   10
+
+what follows is a button ::
+
+    # 0x19, 0x01, 		     //	Usage Minimum (1)		   12
+    # 0x29, 0x03, 		     //	Usage Maximum (3)		   14
+
+first button is button number 1, last button is button number 3 ::
+
+    # 0x15, 0x00, 		     //	Logical Minimum (0)		   16
+    # 0x25, 0x01, 		     //	Logical Maximum (1)		   18
+
+each button can send values from 0 up to including 1
+(i.e. they are binary buttons) ::
+
+    # 0x75, 0x01, 		     //	Report Size (1) 		   20
+
+each button is sent as exactly one bit ::
+
+    # 0x95, 0x03, 		     //	Report Count (3)		   22
+
+and there are three of those bits (matching the three buttons) ::
+
+    # 0x81, 0x02, 		     //	Input (Data,Var,Abs)		   24
+
+it's actual Data (not constant padding), they represent
+a single variable (Var) and their values are Absolute (not relative);
+See HID spec Sec. 6.2.2.5 "Input, Output, and Feature Items" ::
+
+    # 0x75, 0x05, 		     //	Report Size (5) 		   26
+
+five additional padding bits, needed to reach a byte ::
+
+    # 0x95, 0x01, 		     //	Report Count (1)		   28
+
+those five bits are repeated only once ::
+
+    # 0x81, 0x01, 		     //	Input (Cnst,Arr,Abs)		   30
+
+and take Constant (Cnst) values i.e. they can be ignored. ::
+
+    # 0x05, 0x01,		     // Usage Page (Generic Desktop)       32
+    # 0x09, 0x30,		     // Usage (X)			   34
+    # 0x09, 0x31,		     // Usage (Y)			   36
+    # 0x09, 0x38,		     // Usage (Wheel) 		    	   38
+
+The mouse has also two physical positions (Usage (X), Usage (Y))
+and a wheel (Usage (Wheel)) ::
+
+    # 0x15, 0x81, 		     //	Logical Minimum (-127)  	   40
+    # 0x25, 0x7f, 		     //	Logical Maximum (127)		   42
+
+each of them can send values ranging from -127 up to including 127 ::
+
+    # 0x75, 0x08, 		     //	Report Size (8) 		   44
+
+which is represented by eight bits ::
+
+    # 0x95, 0x03, 		     //	Report Count (3)		   46
+
+and there are three of those eight bits, matching X, Y and Wheel. ::
+
+    # 0x81, 0x06,		     // Input (Data,Var,Rel)  	    	   48
+
+This time the data values are Relative (Rel), i.e. they represent
+the change from the previously sent report (event) ::
+
+    # 0xc0,			     // End Collection 		    	   50
+    # 0xc0,			     // End Collection  		   51
+    #
+    R: 52 05 01 09 02 a1 01 09 01 a1 00 05 09 19 01 29 03 15 00 25 01 75 01 95 03 81 02 75 05 95 01 81 01 05 01 09 30 09 31 09 38 15 81 25 7f 75 08 95 03 81 06 c0 c0
+    N: device 0:0
+    I: 3 0001 0001
+
+
+This Report Descriptor tells us that the mouse input will be
+transmitted using four bytes: the first one for the buttons (three
+bits used, five for padding), the last three for the mouse X, Y and
+wheel changes, respectively.
+
+Indeed, for any event, the mouse will send a *report* of four bytes.
+We can check the values sent by resorting e.g. to the `hid-recorder`
+tool, from `hid-tools <https://gitlab.freedesktop.org/libevdev/hid-tools>`_:
+The sequence of bytes sent by clicking and releasing button 1, then button 2, then button 3 is::
+
+  $ sudo ./hid-recorder /dev/hidraw1
+
+  ....
+  output of hid-decode
+  ....
+
+  #  Button: 1  0  0 | # | X:	 0 | Y:    0 | Wheel:	 0
+  E: 000000.000000 4 01 00 00 00
+  #  Button: 0  0  0 | # | X:	 0 | Y:    0 | Wheel:	 0
+  E: 000000.183949 4 00 00 00 00
+  #  Button: 0  1  0 | # | X:	 0 | Y:    0 | Wheel:	 0
+  E: 000001.959698 4 02 00 00 00
+  #  Button: 0  0  0 | # | X:	 0 | Y:    0 | Wheel:	 0
+  E: 000002.103899 4 00 00 00 00
+  #  Button: 0  0  1 | # | X:	 0 | Y:    0 | Wheel:	 0
+  E: 000004.855799 4 04 00 00 00
+  #  Button: 0  0  0 | # | X:    0 | Y:    0 | Wheel:    0
+  E: 000005.103864 4 00 00 00 00
+
+This example shows that when button 2 is clicked,
+the bytes ``02 00 00 00`` are sent, and the immediately subsequent
+event (``00 00 00 00``) is the release of button 2 (no buttons are
+pressed, remember that the data values are *absolute*).
+
+If instead one clicks and holds button 1, then clicks and holds button
+2, releases button 1, and finally releases button 2, the reports are::
+
+  #  Button: 1  0  0 | # | X:    0 | Y:    0 | Wheel:    0
+  E: 000044.175830 4 01 00 00 00
+  #  Button: 1  1  0 | # | X:    0 | Y:    0 | Wheel:    0
+  E: 000045.975997 4 03 00 00 00
+  #  Button: 0  1  0 | # | X:    0 | Y:    0 | Wheel:    0
+  E: 000047.407930 4 02 00 00 00
+  #  Button: 0  0  0 | # | X:    0 | Y:    0 | Wheel:    0
+  E: 000049.199919 4 00 00 00 00
+
+where with ``03 00 00 00`` both buttons are pressed, and with the
+subsequent ``02 00 00 00`` button 1 is released while button 2 is still
+active.
+
+Output, Input and Feature Reports
+---------------------------------
+
+HID devices can have Input Reports, like in the mouse example, Output
+Reports, and Feature Reports. "Output" means that the information is
+sent to the device. For example, a joystick with force feedback will
+have some output; the led of a keyboard would need an output as well.
+"Input" means that data come from the device.
+
+"Feature"s are not meant to be consumed by the end user and define
+configuration options for the device. They can be queried from the host;
+when declared as *Volatile* they should be changed by the host.
+
+
+Collections, Report IDs and Evdev events
+========================================
+
+A single device can logically group data into different independent
+sets, called a *Collection*. Collections can be nested and there are
+different types of collections (see the HID spec 6.2.2.6
+"Collection, End Collection Items" for details).
+
+Different reports are identified by means of different *Report ID*
+fields, i.e. a number identifying the structure of the immediately
+following report.
+Whenever a Report ID is needed it is transmitted as the first byte of
+any report. A device with only one supported HID report (like the mouse
+example above) may omit the report ID.
+
+Consider the following HID report descriptor::
+
+  05 01 09 02 A1 01 85 01 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 F8 26 FF 07 75 0C 95 02 81 06
+  09 38 15 80 25 7F 75 08 95 01 81 06 05 0C 0A 38
+  02 15 80 25 7F 75 08 95 01 81 06 C0 05 01 09 02
+  A1 01 85 02 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 F8 26 FF 07 75 0C 95 02 81 06 09 38 15 80
+  25 7F 75 08 95 01 81 06 05 0C 0A 38 02 15 80 25
+  7F 75 08 95 01 81 06 C0 05 01 09 07 A1 01 85 05
+  05 07 15 00 25 01 09 29 09 3E 09 4B 09 4E 09 E3
+  09 E8 09 E8 09 E8 75 01 95 08 81 02 95 00 81 01
+  C0 05 0C 09 01 A1 01 85 06 15 00 25 01 75 01 95
+  01 09 3F 81 06 09 3F 81 06 09 3F 81 06 09 3F 81
+  06 09 3F 81 06 09 3F 81 06 09 3F 81 06 09 3F 81
+  06 C0 05 0C 09 01 A1 01 85 03 09 05 15 00 26 FF
+  00 75 08 95 02 B1 02 C0
+
+After parsing it (try to parse it on your own using the suggested
+tools!) one can see that the device presents two ``Mouse`` Application
+Collections (with reports identified by Reports IDs 1 and 2,
+respectively), a ``Keypad`` Application Collection (whose report is
+identified by the Report ID 5) and two ``Consumer Controls`` Application
+Collections, (with Report IDs 6 and 3, respectively). Note, however,
+that a device can have different Report IDs for the same Application
+Collection.
+
+The data sent will begin with the Report ID byte, and will be followed
+by the corresponding information. For example, the data transmitted for
+the last consumer control::
+
+  0x05, 0x0C,        // Usage Page (Consumer)
+  0x09, 0x01,        // Usage (Consumer Control)
+  0xA1, 0x01,        // Collection (Application)
+  0x85, 0x03,        //   Report ID (3)
+  0x09, 0x05,        //   Usage (Headphone)
+  0x15, 0x00,        //   Logical Minimum (0)
+  0x26, 0xFF, 0x00,  //   Logical Maximum (255)
+  0x75, 0x08,        //   Report Size (8)
+  0x95, 0x02,        //   Report Count (2)
+  0xB1, 0x02,        //   Feature (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position,Non-volatile)
+  0xC0,              // End Collection
+
+will be of three bytes: the first for the Report ID (3), the next two
+for the headphone, with two (``Report Count (2)``) bytes
+(``Report Size (8)``), each ranging from 0 (``Logical Minimum (0)``)
+to 255 (``Logical Maximum (255)``).
+
+All the Input data sent by the device should be translated into
+corresponding Evdev events, so that the remaining part of the stack can
+know what is going on, e.g. the bit for the first button translates into
+the ``EV_KEY/BTN_LEFT`` evdev event and relative X movement translates
+into the ``EV_REL/REL_X`` evdev event".
+
+Events
+======
+
+In Linux, one ``/dev/input/event*`` is created for each ``Application
+Collection``. Going back to the mouse example, and repeating the
+sequence where one clicks and holds button 1, then clicks and holds
+button 2, releases button 1, and finally releases button 2, one gets::
+
+  $ sudo libinput record /dev/input/event1
+  # libinput record
+  version: 1
+  ndevices: 1
+  libinput:
+    version: "1.23.0"
+    git: "unknown"
+  system:
+    os: "opensuse-tumbleweed:20230619"
+    kernel: "6.3.7-1-default"
+    dmi: "dmi:bvnHP:bvrU77Ver.01.05.00:bd03/24/2022:br5.0:efr20.29:svnHP:pnHPEliteBook64514inchG9NotebookPC:pvr:rvnHP:rn89D2:rvrKBCVersion14.1D.00:cvnHP:ct10:cvr:sku5Y3J1EA#ABZ:"
+  devices:
+  - node: /dev/input/event1
+    evdev:
+      # Name: PixArt HP USB Optical Mouse
+      # ID: bus 0x3 vendor 0x3f0 product 0x94a version 0x111
+      # Supported Events:
+      # Event type 0 (EV_SYN)
+      # Event type 1 (EV_KEY)
+      #   Event code 272 (BTN_LEFT)
+      #   Event code 273 (BTN_RIGHT)
+      #   Event code 274 (BTN_MIDDLE)
+      # Event type 2 (EV_REL)
+      #   Event code 0 (REL_X)
+      #   Event code 1 (REL_Y)
+      #   Event code 8 (REL_WHEEL)
+      #   Event code 11 (REL_WHEEL_HI_RES)
+      # Event type 4 (EV_MSC)
+      #   Event code 4 (MSC_SCAN)
+      # Properties:
+      name: "PixArt HP USB Optical Mouse"
+      id: [3, 1008, 2378, 273]
+      codes:
+  	0: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] # EV_SYN
+  	1: [272, 273, 274] # EV_KEY
+  	2: [0, 1, 8, 11] # EV_REL
+  	4: [4] # EV_MSC
+      properties: []
+    hid: [
+      0x05, 0x01, 0x09, 0x02, 0xa1, 0x01, 0x09, 0x01, 0xa1, 0x00, 0x05, 0x09, 0x19, 0x01, 0x29, 0x03,
+      0x15, 0x00, 0x25, 0x01, 0x95, 0x08, 0x75, 0x01, 0x81, 0x02, 0x05, 0x01, 0x09, 0x30, 0x09, 0x31,
+      0x09, 0x38, 0x15, 0x81, 0x25, 0x7f, 0x75, 0x08, 0x95, 0x03, 0x81, 0x06, 0xc0, 0xc0
+    ]
+    udev:
+      properties:
+      - ID_INPUT=1
+      - ID_INPUT_MOUSE=1
+      - LIBINPUT_DEVICE_GROUP=3/3f0/94a:usb-0000:05:00.3-2
+    quirks:
+    events:
+    # Current time is 12:31:56
+    - evdev:
+      - [  0,	   0,	4,   4,      30] # EV_MSC / MSC_SCAN		     30 (obfuscated)
+      - [  0,	   0,	1, 272,       1] # EV_KEY / BTN_LEFT		      1
+      - [  0,	   0,	0,   0,       0] # ------------ SYN_REPORT (0) ---------- +0ms
+    - evdev:
+      - [  1, 207892,	4,   4,      30] # EV_MSC / MSC_SCAN		     30 (obfuscated)
+      - [  1, 207892,	1, 273,       1] # EV_KEY / BTN_RIGHT		      1
+      - [  1, 207892,	0,   0,       0] # ------------ SYN_REPORT (0) ---------- +1207ms
+    - evdev:
+      - [  2, 367823,	4,   4,      30] # EV_MSC / MSC_SCAN		     30 (obfuscated)
+      - [  2, 367823,	1, 272,       0] # EV_KEY / BTN_LEFT		      0
+      - [  2, 367823,	0,   0,       0] # ------------ SYN_REPORT (0) ---------- +1160ms
+    # Current time is 12:32:00
+    - evdev:
+      - [  3, 247617,	4,   4,      30] # EV_MSC / MSC_SCAN		     30 (obfuscated)
+      - [  3, 247617,	1, 273,       0] # EV_KEY / BTN_RIGHT		      0
+      - [  3, 247617,   0,   0,       0] # ------------ SYN_REPORT (0) ---------- +880ms
+
+Note: if ``libinput record`` is not available on your system try using
+``evemu-record``.
+
+When something does not work
+============================
+
+There can be a number of reasons why a device does not behave
+correctly. For example
+
+* The HID report descriptor provided by the HID device may be wrong
+  because e.g.
+
+  * it does not follow the standard, so that the kernel
+    will not able to make sense of the HID report descriptor;
+  * the HID report descriptor *does not match* what is actually
+    sent by the device (this can be verified by reading the raw HID
+    data);
+* the HID report descriptor may need some "quirks" (see later on).
+
+As a consequence, a ``/dev/input/event*`` may not be created
+for each Application Collection, and/or the events
+there may not match what you would expect.
+
+
+Quirks
+------
+
+There are some known peculiarities of HID devices that the kernel
+knows how to fix - these are called the HID quirks and a list of those
+is available in `include/linux/hid.h`.
+
+Should this be the case, it should be enough to add the required quirk
+in the kernel, for the HID device at hand. This can be done in the file
+`drivers/hid/hid-quirks.c`. How to do it should be relatively
+straightforward after looking into the file.
+
+The list of currently defined quirks, from `include/linux/hid.h`, is
+
+.. kernel-doc:: include/linux/hid.h
+   :doc: HID quirks
+
+Quirks for USB devices can be specified while loading the usbhid module,
+see ``modinfo usbhid``, although the proper fix should go into
+hid-quirks.c and **be submitted upstream**.
+See Documentation/process/submitting-patches.rst for guidelines on how
+to submit a patch. Quirks for other busses need to go into hid-quirks.c.
+
+Fixing HID report descriptors
+-----------------------------
+
+Should you need to patch HID report descriptors the easiest way is to
+resort to eBPF, as described in Documentation/hid/hid-bpf.rst.
+
+Basically, you can change any byte of the original HID report
+descriptor. The examples in samples/hid should be a good starting point
+for your code, see e.g. `samples/hid/hid_mouse.bpf.c`::
+
+  SEC("fmod_ret/hid_bpf_rdesc_fixup")
+  int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hctx)
+  {
+    ....
+       data[39] = 0x31;
+       data[41] = 0x30;
+    return 0;
+  }
+
+Of course this can be also done within the kernel source code, see e.g.
+`drivers/hid/hid-aureal.c` or `drivers/hid/hid-samsung.c` for a slightly
+more complex file.
+
+Check Documentation/hid/hidreport-parsing.rst if you need any help
+navigating the HID manuals and understanding the exact meaning of
+the HID report descriptor hex numbers.
+
+Whatever solution you come up with, please remember to **submit the
+fix to the HID maintainers**, so that it can be directly integrated in
+the kernel and that particular HID device will start working for
+everyone else. See Documentation/process/submitting-patches.rst for
+guidelines on how to do this.
+
+
+Modifying the transmitted data on the fly
+-----------------------------------------
+
+Using eBPF it is also possible to modify the data exchanged with the
+device. See again the examples in `samples/hid`.
+
+Again, **please post your fix**, so that it can be integrated in the
+kernel!
+
+Writing a specialized driver
+----------------------------
+
+This should really be your last resort.
+
+
+.. rubric:: Footnotes
+
+.. [#hidraw] read hidraw: see Documentation/hid/hidraw.rst and
+  file `samples/hidraw/hid-example.c` for an example.
+  The output of ``hid-example`` would be, for the same mouse::
+
+    $ sudo ./hid-example
+    Report Descriptor Size: 52
+    Report Descriptor:
+    5 1 9 2 a1 1 9 1 a1 0 5 9 19 1 29 3 15 0 25 1 75 1 95 3 81 2 75 5 95 1 81 1 5 1 9 30 9 31 9 38 15 81 25 7f 75 8 95 3 81 6 c0 c0
+
+    Raw Name: PixArt USB Optical Mouse
+    Raw Phys: usb-0000:05:00.4-2.3/input0
+    Raw Info:
+            bustype: 3 (USB)
+            vendor: 0x093a
+            product: 0x2510
+    ...

Documentation/hid/hidreport-parsing.rst

···
+.. SPDX-License-Identifier: GPL-2.0
+
+========================================
+Manual parsing of HID report descriptors
+========================================
+
+Consider again the mouse HID report descriptor
+introduced in Documentation/hid/hidintro.rst::
+
+  $ hexdump -C /sys/bus/hid/devices/0003\:093A\:2510.0002/report_descriptor
+  00000000  05 01 09 02 a1 01 09 01  a1 00 05 09 19 01 29 03  |..............).|
+  00000010  15 00 25 01 75 01 95 03  81 02 75 05 95 01 81 01  |..%.u.....u.....|
+  00000020  05 01 09 30 09 31 09 38  15 81 25 7f 75 08 95 03  |...0.1.8..%.u...|
+  00000030  81 06 c0 c0                                       |....|
+  00000034
+
+and try to parse it by hand.
+
+Start with the first number, 0x05: it carries 2 bits for the
+length of the item, 2 bits for the type of the item and 4 bits for the
+function::
+
+  +----------+
+  | 00000101 |
+  +----------+
+          ^^
+          ---- Length of data (see HID spec 6.2.2.2)
+        ^^
+        ------ Type of the item (see HID spec 6.2.2.2, then jump to 6.2.2.7)
+    ^^^^
+    --------- Function of the item (see HID spec 6.2.2.7, then HUT Sec 3)
+
+In our case, the length is 1 byte, the type is ``Global`` and the
+function is ``Usage Page``, thus for parsing the value 0x01 in the second byte
+we need to refer to HUT Sec 3.
+
+The second number is the actual data, and its meaning can be found in
+the HUT. We have a ``Usage Page``, thus we need to refer to HUT
+Sec. 3, "Usage Pages"; from there, one sees that ``0x01`` stands for
+``Generic Desktop Page``.
+
+Moving now to the second two bytes, and following the same scheme,
+``0x09`` (i.e. ``00001001``) will be followed by one byte (``01``)
+and is a ``Local`` item (``10``). Thus, the meaning of the remaining four bits
+(``0000``) is given in the HID spec Sec. 6.2.2.8 "Local Items", so that
+we have a ``Usage``. From HUT, Sec. 4, "Generic Desktop Page",  we see that
+0x02 stands for ``Mouse``.
+
+The following numbers can be parsed in the same way.

Documentation/hid/index.rst

···
 .. toctree::
    :maxdepth: 1
 
+   hidintro
    hiddev
    hidraw
    hid-sensor

MAINTAINERS

···
 F:	fs/ufs/
 
 UHID USERSPACE HID IO DRIVER
-M:	David Rheinsberg <[e-mail]>
+M:	David Rheinsberg <[e-mail]>
 L:	[e-mail]
 S:	Maintained
 F:	drivers/hid/uhid.c
···
 F:	drivers/rtc/rtc-sd3078.c
 
 WIIMOTE HID DRIVER
-M:	David Rheinsberg <[e-mail]>
+M:	David Rheinsberg <[e-mail]>
 L:	[e-mail]
 S:	Maintained
 F:	drivers/hid/hid-wiimote*

drivers/hid/Kconfig

···
 	help
 	Say Y here if you have a Google Hammer device.
 
+config HID_GOOGLE_STADIA_FF
+	tristate "Google Stadia force feedback"
+	select INPUT_FF_MEMLESS
+	help
+	Say Y here if you want to enable force feedback support for the Google
+	Stadia controller.
+
 config HID_VIVALDI
 	tristate "Vivaldi Keyboard"
 	select HID_VIVALDI_COMMON
···
 	Deck.
 
 config HID_STEELSERIES
-	tristate "Steelseries SRW-S1 steering wheel support"
+	tristate "Steelseries devices support"
+	depends on USB_HID
 	help
-	Support for Steelseries SRW-S1 steering wheel
+	Support for Steelseries SRW-S1 steering wheel, and the Steelseries
+	Arctis 1 Wireless for XBox headset.
 
 config HID_SUNPLUS
 	tristate "Sunplus wireless desktop"

drivers/hid/Makefile

···
 obj-$(CONFIG_HID_GLORIOUS)  += hid-glorious.o
 obj-$(CONFIG_HID_VIVALDI_COMMON) += hid-vivaldi-common.o
 obj-$(CONFIG_HID_GOOGLE_HAMMER)	+= hid-google-hammer.o
+obj-$(CONFIG_HID_GOOGLE_STADIA_FF)	+= hid-google-stadiaff.o
 obj-$(CONFIG_HID_VIVALDI)	+= hid-vivaldi.o
 obj-$(CONFIG_HID_GT683R)	+= hid-gt683r.o
 obj-$(CONFIG_HID_GYRATION)	+= hid-gyration.o

drivers/hid/hid-apple.c

···
 	{ "SONiX USB DEVICE" },
 	{ "Keychron" },
 	{ "AONE" },
-	{ "GANSS" }
+	{ "GANSS" },
+	{ "Hailuck" },
 };
 
 static bool apple_is_non_apple_keyboard(struct hid_device *hdev)

drivers/hid/hid-cp2112.c

···
  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
  */
 
-#include <linux/gpio/consumer.h>
-#include <linux/gpio/machine.h>
+#include <linux/bitops.h>
 #include <linux/gpio/driver.h>
 #include <linux/hid.h>
 #include <linux/hidraw.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/nls.h>
+#include <linux/string_choices.h>
 #include <linux/usb/ch9.h>
 #include "hid-ids.h"
 
···
 #define CP2112_GPIO_CONFIG_LENGTH		5
 #define CP2112_GPIO_GET_LENGTH			2
 #define CP2112_GPIO_SET_LENGTH			3
+#define CP2112_GPIO_MAX_GPIO			8
+#define CP2112_GPIO_ALL_GPIO_MASK		GENMASK(7, 0)
 
 enum {
 	CP2112_GPIO_CONFIG		= 0x02,
···
 	atomic_t read_avail;
 	atomic_t xfer_avail;
 	struct gpio_chip gc;
-	struct irq_chip irq;
 	u8 *in_out_buffer;
 	struct mutex lock;
 
-	struct gpio_desc *desc[8];
 	bool gpio_poll;
 	struct delayed_work gpio_poll_worker;
 	unsigned long irq_mask;
 	u8 gpio_prev_state;
 };
 
-static int gpio_push_pull = 0xFF;
-module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
+static int gpio_push_pull = CP2112_GPIO_ALL_GPIO_MASK;
+module_param(gpio_push_pull, int, 0644);
 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
 
 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
···
 		goto exit;
 	}
 
-	buf[1] &= ~(1 << offset);
+	buf[1] &= ~BIT(offset);
 	buf[2] = gpio_push_pull;
 
 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
···
 	mutex_lock(&dev->lock);
 
 	buf[0] = CP2112_GPIO_SET;
-	buf[1] = value ? 0xff : 0;
-	buf[2] = 1 << offset;
+	buf[1] = value ? CP2112_GPIO_ALL_GPIO_MASK : 0;
+	buf[2] = BIT(offset);
 
 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
···
 	hid_dbg(hdev, "I2C %d messages\n", num);
 
 	if (num == 1) {
+		hid_dbg(hdev, "I2C %s %#04x len %d\n",
+			str_read_write(msgs->flags & I2C_M_RD), msgs->addr, msgs->len);
 		if (msgs->flags & I2C_M_RD) {
-			hid_dbg(hdev, "I2C read %#04x len %d\n",
-				msgs->addr, msgs->len);
 			read_length = msgs->len;
 			read_buf = msgs->buf;
 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
 		} else {
-			hid_dbg(hdev, "I2C write %#04x len %d\n",
-				msgs->addr, msgs->len);
 			count = cp2112_i2c_write_req(buf, msgs->addr,
 						     msgs->buf, msgs->len);
 		}
···
 	int ret;
 
 	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
-		read_write == I2C_SMBUS_WRITE ? "write" : "read",
+		str_write_read(read_write == I2C_SMBUS_WRITE),
 		addr, flags, command, size);
 
 	switch (size) {
···
 	int ret = cp2112_get_usb_config(hdev, &cfg); \
 	if (ret) \
 		return ret; \
-	return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
+	return sysfs_emit(buf, format, ##__VA_ARGS__); \
 } \
 static DEVICE_ATTR_RW(name);
 
···
 
 #undef CP2112_CONFIG_ATTR
 
-struct cp2112_pstring_attribute {
-	struct device_attribute attr;
-	unsigned char report;
-};
-
-static ssize_t pstr_store(struct device *kdev,
-			  struct device_attribute *kattr, const char *buf,
-			  size_t count)
+static ssize_t pstr_store(struct device *kdev, struct device_attribute *kattr,
+			  const char *buf, size_t count, int number)
 {
 	struct hid_device *hdev = to_hid_device(kdev);
-	struct cp2112_pstring_attribute *attr =
-		container_of(kattr, struct cp2112_pstring_attribute, attr);
 	struct cp2112_string_report report;
 	int ret;
 
···
 
 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
 			      report.string, ARRAY_SIZE(report.string));
-	report.report = attr->report;
+	report.report = number;
 	report.length = ret * sizeof(report.string[0]) + 2;
 	report.type = USB_DT_STRING;
 
···
 	return count;
 }
 
-static ssize_t pstr_show(struct device *kdev,
-			 struct device_attribute *kattr, char *buf)
+static ssize_t pstr_show(struct device *kdev, struct device_attribute *kattr,
+			 char *buf, int number)
 {
 	struct hid_device *hdev = to_hid_device(kdev);
-	struct cp2112_pstring_attribute *attr =
-		container_of(kattr, struct cp2112_pstring_attribute, attr);
 	struct cp2112_string_report report;
 	u8 length;
 	int ret;
 
-	ret = cp2112_hid_get(hdev, attr->report, (u8 *)&report.contents,
+	ret = cp2112_hid_get(hdev, number, (u8 *)&report.contents,
 			     sizeof(report.contents), HID_FEATURE_REPORT);
 	if (ret < 3) {
 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
···
 }
 
 #define CP2112_PSTR_ATTR(name, _report) \
-static struct cp2112_pstring_attribute dev_attr_##name = { \
-	.attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
-	.report = _report, \
-};
+static ssize_t name##_store(struct device *kdev, struct device_attribute *kattr, \
+			    const char *buf, size_t count) \
+{ \
+	return pstr_store(kdev, kattr, buf, count, _report); \
+} \
+static ssize_t name##_show(struct device *kdev, struct device_attribute *kattr, char *buf) \
+{ \
+	return pstr_show(kdev, kattr, buf, _report); \
+} \
+static DEVICE_ATTR_RW(name);
 
 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
···
 		&dev_attr_max_power.attr,
 		&dev_attr_power_mode.attr,
 		&dev_attr_release_version.attr,
-		&dev_attr_manufacturer.attr.attr,
-		&dev_attr_product.attr.attr,
-		&dev_attr_serial.attr.attr,
+		&dev_attr_manufacturer.attr,
+		&dev_attr_product.attr,
+		&dev_attr_serial.attr,
 		NULL
 	}
 };
···
 	}
 
 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
-		umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
+		umode_t mode = (buf[1] & 1) ? 0644 : 0444;
 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
 		if (ret < 0)
 			hid_err(hdev, "error chmoding sysfs file %s\n",
···
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct cp2112_device *dev = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
 
-	__clear_bit(d->hwirq, &dev->irq_mask);
+	__clear_bit(hwirq, &dev->irq_mask);
+	gpiochip_disable_irq(gc, hwirq);
 }
 
 static void cp2112_gpio_irq_unmask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct cp2112_device *dev = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
 
-	__set_bit(d->hwirq, &dev->irq_mask);
+	gpiochip_enable_irq(gc, hwirq);
+	__set_bit(hwirq, &dev->irq_mask);
 }
 
 static void cp2112_gpio_poll_callback(struct work_struct *work)
···
 						 gpio_poll_worker.work);
 	struct irq_data *d;
 	u8 gpio_mask;
-	u8 virqs = (u8)dev->irq_mask;
 	u32 irq_type;
 	int irq, virq, ret;
 
···
 		goto exit;
 
 	gpio_mask = ret;
-
-	while (virqs) {
-		virq = ffs(virqs) - 1;
-		virqs &= ~BIT(virq);
-
-		if (!dev->gc.to_irq)
-			break;
-
-		irq = dev->gc.to_irq(&dev->gc, virq);
+	for_each_set_bit(virq, &dev->irq_mask, CP2112_GPIO_MAX_GPIO) {
+		irq = irq_find_mapping(dev->gc.irq.domain, virq);
+		if (!irq)
+			continue;
 
 		d = irq_get_irq_data(irq);
 		if (!d)
···
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct cp2112_device *dev = gpiochip_get_data(gc);
 
+	cp2112_gpio_irq_mask(d);
 	cancel_delayed_work_sync(&dev->gpio_poll_worker);
 }
 
···
 	return 0;
 }
 
-static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
-					      int pin)
-{
-	int ret;
-
-	if (dev->desc[pin])
-		return -EINVAL;
-
-	dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
-						   "HID/I2C:Event",
-						   GPIO_ACTIVE_HIGH,
-						   GPIOD_IN);
-	if (IS_ERR(dev->desc[pin])) {
-		dev_err(dev->gc.parent, "Failed to request GPIO\n");
-		return PTR_ERR(dev->desc[pin]);
-	}
-
-	ret = cp2112_gpio_direction_input(&dev->gc, pin);
-	if (ret < 0) {
-		dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n");
-		goto err_desc;
-	}
-
-	ret = gpiochip_lock_as_irq(&dev->gc, pin);
-	if (ret) {
-		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
-		goto err_desc;
-	}
-
-	ret = gpiod_to_irq(dev->desc[pin]);
-	if (ret < 0) {
-		dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
-		goto err_lock;
-	}
-
-	return ret;
-
-err_lock:
-	gpiochip_unlock_as_irq(&dev->gc, pin);
-err_desc:
-	gpiochip_free_own_desc(dev->desc[pin]);
-	dev->desc[pin] = NULL;
-	return ret;
-}
+static const struct irq_chip cp2112_gpio_irqchip = {
+	.name = "cp2112-gpio",
+	.irq_startup = cp2112_gpio_irq_startup,
+	.irq_shutdown = cp2112_gpio_irq_shutdown,
+	.irq_ack = cp2112_gpio_irq_ack,
+	.irq_mask = cp2112_gpio_irq_mask,
+	.irq_unmask = cp2112_gpio_irq_unmask,
+	.irq_set_type = cp2112_gpio_irq_type,
+	.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
 
 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
···
 	dev->gc.set			= cp2112_gpio_set;
 	dev->gc.get			= cp2112_gpio_get;
 	dev->gc.base			= -1;
-	dev->gc.ngpio			= 8;
+	dev->gc.ngpio			= CP2112_GPIO_MAX_GPIO;
 	dev->gc.can_sleep		= 1;
 	dev->gc.parent			= &hdev->dev;
 
-	dev->irq.name = "cp2112-gpio";
-	dev->irq.irq_startup = cp2112_gpio_irq_startup;
-	dev->irq.irq_shutdown = cp2112_gpio_irq_shutdown;
-	dev->irq.irq_ack = cp2112_gpio_irq_ack;
-	dev->irq.irq_mask = cp2112_gpio_irq_mask;
-	dev->irq.irq_unmask = cp2112_gpio_irq_unmask;
-	dev->irq.irq_set_type = cp2112_gpio_irq_type;
-	dev->irq.flags = IRQCHIP_MASK_ON_SUSPEND;
-
 	girq = &dev->gc.irq;
-	girq->chip = &dev->irq;
+	gpio_irq_chip_set_chip(girq, &cp2112_gpio_irqchip);
 	/* The event comes from the outside so no parent handler */
 	girq->parent_handler = NULL;
 	girq->num_parents = 0;
···
 static void cp2112_remove(struct hid_device *hdev)
 {
 	struct cp2112_device *dev = hid_get_drvdata(hdev);
-	int i;
 
 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
 	i2c_del_adapter(&dev->adap);
···
 	if (dev->gpio_poll) {
 		dev->gpio_poll = false;
 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
-	}
-
-	for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
-		gpiochip_unlock_as_irq(&dev->gc, i);
-		gpiochip_free_own_desc(dev->desc[i]);
 	}
 
 	gpiochip_remove(&dev->gc);

drivers/hid/hid-google-stadiaff.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Stadia controller rumble support.
+ *
+ * Copyright 2023 Google LLC
+ */
+
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define STADIA_FF_REPORT_ID 5
+
+struct stadiaff_device {
+	struct hid_device *hid;
+	struct hid_report *report;
+	spinlock_t lock;
+	bool removed;
+	uint16_t strong_magnitude;
+	uint16_t weak_magnitude;
+	struct work_struct work;
+};
+
+static void stadiaff_work(struct work_struct *work)
+{
+	struct stadiaff_device *stadiaff =
+		container_of(work, struct stadiaff_device, work);
+	struct hid_field *rumble_field = stadiaff->report->field[0];
+	unsigned long flags;
+
+	spin_lock_irqsave(&stadiaff->lock, flags);
+	rumble_field->value[0] = stadiaff->strong_magnitude;
+	rumble_field->value[1] = stadiaff->weak_magnitude;
+	spin_unlock_irqrestore(&stadiaff->lock, flags);
+
+	hid_hw_request(stadiaff->hid, stadiaff->report, HID_REQ_SET_REPORT);
+}
+
+static int stadiaff_play(struct input_dev *dev, void *data,
+			 struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
+	unsigned long flags;
+
+	spin_lock_irqsave(&stadiaff->lock, flags);
+	if (!stadiaff->removed) {
+		stadiaff->strong_magnitude = effect->u.rumble.strong_magnitude;
+		stadiaff->weak_magnitude = effect->u.rumble.weak_magnitude;
+		schedule_work(&stadiaff->work);
+	}
+	spin_unlock_irqrestore(&stadiaff->lock, flags);
+
+	return 0;
+}
+
+static int stadiaff_init(struct hid_device *hid)
+{
+	struct stadiaff_device *stadiaff;
+	struct hid_report *report;
+	struct hid_input *hidinput;
+	struct input_dev *dev;
+	int error;
+
+	if (list_empty(&hid->inputs)) {
+		hid_err(hid, "no inputs found\n");
+		return -ENODEV;
+	}
+	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+	dev = hidinput->input;
+
+	report = hid_validate_values(hid, HID_OUTPUT_REPORT,
+				     STADIA_FF_REPORT_ID, 0, 2);
+	if (!report)
+		return -ENODEV;
+
+	stadiaff = devm_kzalloc(&hid->dev, sizeof(struct stadiaff_device),
+				GFP_KERNEL);
+	if (!stadiaff)
+		return -ENOMEM;
+
+	hid_set_drvdata(hid, stadiaff);
+
+	input_set_capability(dev, EV_FF, FF_RUMBLE);
+
+	error = input_ff_create_memless(dev, NULL, stadiaff_play);
+	if (error)
+		return error;
+
+	stadiaff->removed = false;
+	stadiaff->hid = hid;
+	stadiaff->report = report;
+	INIT_WORK(&stadiaff->work, stadiaff_work);
+	spin_lock_init(&stadiaff->lock);
+
+	hid_info(hid, "Force Feedback for Google Stadia controller\n");
+
+	return 0;
+}
+
+static int stadia_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
+	if (ret) {
+		hid_err(hdev, "hw start failed\n");
+		return ret;
+	}
+
+	ret = stadiaff_init(hdev);
+	if (ret) {
+		hid_err(hdev, "force feedback init failed\n");
+		hid_hw_stop(hdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void stadia_remove(struct hid_device *hid)
+{
+	struct stadiaff_device *stadiaff = hid_get_drvdata(hid);
+	unsigned long flags;
+
+	spin_lock_irqsave(&stadiaff->lock, flags);
+	stadiaff->removed = true;
+	spin_unlock_irqrestore(&stadiaff->lock, flags);
+
+	cancel_work_sync(&stadiaff->work);
+	hid_hw_stop(hid);
+}
+
+static const struct hid_device_id stadia_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_GOOGLE, USB_DEVICE_ID_GOOGLE_STADIA) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, stadia_devices);
+
+static struct hid_driver stadia_driver = {
+	.name = "stadia",
+	.id_table = stadia_devices,
+	.probe = stadia_probe,
+	.remove = stadia_remove,
+};
+module_hid_driver(stadia_driver);
+
+MODULE_LICENSE("GPL");

drivers/hid/hid-ids.h

···
 #define USB_DEVICE_ID_GOOGLE_DON	0x5050
 #define USB_DEVICE_ID_GOOGLE_EEL	0x5057
 #define USB_DEVICE_ID_GOOGLE_JEWEL	0x5061
+#define USB_DEVICE_ID_GOOGLE_STADIA	0x9400
 
 #define USB_VENDOR_ID_GOTOP		0x08f2
 #define USB_DEVICE_ID_SUPER_Q2		0x007f
···
 #define USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_2		0xc534
 #define USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1	0xc539
 #define USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1_1	0xc53f
+#define USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1_2	0xc547
 #define USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_POWERPLAY	0xc53a
 #define USB_DEVICE_ID_SPACETRAVELLER	0xc623
 #define USB_DEVICE_ID_SPACENAVIGATOR	0xc626

drivers/hid/hid-input.c

···
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
 		USB_DEVICE_ID_APPLE_ALU_WIRELESS_ANSI),
 	  HID_BATTERY_QUIRK_PERCENT | HID_BATTERY_QUIRK_FEATURE },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
+		USB_DEVICE_ID_APPLE_MAGICTRACKPAD),
+	  HID_BATTERY_QUIRK_IGNORE },
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM,
 		USB_DEVICE_ID_ELECOM_BM084),
 	  HID_BATTERY_QUIRK_IGNORE },
···
 			return;
 
 		case 0x3c: /* Invert */
+			device->quirks &= ~HID_QUIRK_NOINVERT;
 			map_key_clear(BTN_TOOL_RUBBER);
 			break;
 
···
 		case 0x45: /* ERASER */
 			/*
 			 * This event is reported when eraser tip touches the surface.
-			 * Actual eraser (BTN_TOOL_RUBBER) is set by Invert usage when
-			 * tool gets in proximity.
+			 * Actual eraser (BTN_TOOL_RUBBER) is set and released either
+			 * by Invert if tool reports proximity or by Eraser directly.
 			 */
+			if (!test_bit(BTN_TOOL_RUBBER, input->keybit)) {
+				device->quirks |= HID_QUIRK_NOINVERT;
+				set_bit(BTN_TOOL_RUBBER, input->keybit);
+			}
 			map_key_clear(BTN_TOUCH);
 			break;
 
···
 		else if (report->tool != BTN_TOOL_RUBBER)
 			/* value is off, tool is not rubber, ignore */
 			return;
+		else if (*quirks & HID_QUIRK_NOINVERT &&
+			 !test_bit(BTN_TOUCH, input->key)) {
+			/*
+			 * There is no invert to release the tool, let hid_input
+			 * send BTN_TOUCH with scancode and release the tool after.
+			 */
+			hid_report_release_tool(report, input, BTN_TOOL_RUBBER);
+			return;
+		}
 
 		/* let hid-input set BTN_TOUCH */
 		break;

drivers/hid/hid-logitech-dj.c

···
 		 * 50 msec should gives enough time to the receiver to be ready.
 		 */
 		msleep(50);
+
+		if (retval)
+			return retval;
 	}
 
 	/*
···
 	buf[5] = 0x09;
 	buf[6] = 0x00;
 
-	hid_hw_raw_request(hdev, REPORT_ID_HIDPP_SHORT, buf,
+	retval = hid_hw_raw_request(hdev, REPORT_ID_HIDPP_SHORT, buf,
 			HIDPP_REPORT_SHORT_LENGTH, HID_OUTPUT_REPORT,
 			HID_REQ_SET_REPORT);
 
···
 		}
 		/*
 		 * Mouse-only receivers send unnumbered mouse data. The 27 MHz
-		 * receiver uses 6 byte packets, the nano receiver 8 bytes.
+		 * receiver uses 6 byte packets, the nano receiver 8 bytes,
+		 * the lightspeed receiver (Pro X Superlight) 13 bytes.
 		 */
 		if (djrcv_dev->unnumbered_application == HID_GD_MOUSE &&
-		    size <= 8) {
-			u8 mouse_report[9];
+		    size <= 13){
+			u8 mouse_report[14];
 
 			/* Prepend report id */
 			mouse_report[0] = REPORT_TYPE_MOUSE;
···
 	{ /* Logitech lightspeed receiver (0xc53f) */
 	  HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
 		USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1_1),
+	 .driver_data = recvr_type_gaming_hidpp},
+	{ /* Logitech lightspeed receiver (0xc547) */
+	  HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH,
+		USB_DEVICE_ID_LOGITECH_NANO_RECEIVER_LIGHTSPEED_1_2),
 	 .driver_data = recvr_type_gaming_hidpp},
 
 	{ /* Logitech 27 MHz HID++ 1.0 receiver (0xc513) */

drivers/hid/hid-logitech-hidpp.c

···
 #define HIDPP20_ERROR_INVALID_ARGS		0x02
 #define HIDPP20_ERROR_OUT_OF_RANGE		0x03
 #define HIDPP20_ERROR_HW_ERROR			0x04
-#define HIDPP20_ERROR_LOGITECH_INTERNAL		0x05
+#define HIDPP20_ERROR_NOT_ALLOWED		0x05
 #define HIDPP20_ERROR_INVALID_FEATURE_INDEX	0x06
 #define HIDPP20_ERROR_INVALID_FUNCTION_ID	0x07
 #define HIDPP20_ERROR_BUSY			0x08
···
 }
 
 /*
- * hidpp_send_message_sync() returns 0 in case of success, and something else
- * in case of a failure.
- * - If ' something else' is positive, that means that an error has been raised
- *   by the protocol itself.
- * - If ' something else' is negative, that means that we had a classic error
- *   (-ENOMEM, -EPIPE, etc...)
+ * Effectively send the message to the device, waiting for its answer.
+ *
+ * Must be called with hidpp->send_mutex locked
+ *
+ * Same return protocol than hidpp_send_message_sync():
+ * - success on 0
+ * - negative error means transport error
+ * - positive value means protocol error
  */
-static int hidpp_send_message_sync(struct hidpp_device *hidpp,
+static int __do_hidpp_send_message_sync(struct hidpp_device *hidpp,
 	struct hidpp_report *message,
 	struct hidpp_report *response)
 {
-	int ret = -1;
-	int max_retries = 3;
+	int ret;
 
-	mutex_lock(&hidpp->send_mutex);
+	__must_hold(&hidpp->send_mutex);
 
 	hidpp->send_receive_buf = response;
 	hidpp->answer_available = false;
···
 	 */
 	*response = *message;
 
-	for (; max_retries != 0 && ret; max_retries--) {
-		ret = __hidpp_send_report(hidpp->hid_dev, message);
-
-		if (ret) {
-			dbg_hid("__hidpp_send_report returned err: %d\n", ret);
-			memset(response, 0, sizeof(struct hidpp_report));
-			break;
-		}
-
-		if (!wait_event_timeout(hidpp->wait, hidpp->answer_available,
-					5*HZ)) {
-			dbg_hid("%s:timeout waiting for response\n", __func__);
-			memset(response, 0, sizeof(struct hidpp_report));
-			ret = -ETIMEDOUT;
-			break;
-		}
-
-		if (response->report_id == REPORT_ID_HIDPP_SHORT &&
-		    response->rap.sub_id == HIDPP_ERROR) {
-			ret = response->rap.params[1];
-			dbg_hid("%s:got hidpp error %02X\n", __func__, ret);
-			break;
-		}
-
-		if ((response->report_id == REPORT_ID_HIDPP_LONG ||
-		     response->report_id == REPORT_ID_HIDPP_VERY_LONG) &&
-		    response->fap.feature_index == HIDPP20_ERROR) {
-			ret = response->fap.params[1];
-			if (ret != HIDPP20_ERROR_BUSY) {
-				dbg_hid("%s:got hidpp 2.0 error %02X\n", __func__, ret);
-				break;
-			}
-			dbg_hid("%s:got busy hidpp 2.0 error %02X, retrying\n", __func__, ret);
-		}
+	ret = __hidpp_send_report(hidpp->hid_dev, message);
+	if (ret) {
+		dbg_hid("__hidpp_send_report returned err: %d\n", ret);
+		memset(response, 0, sizeof(struct hidpp_report));
+		return ret;
 	}
+
+	if (!wait_event_timeout(hidpp->wait, hidpp->answer_available,
+				5*HZ)) {
+		dbg_hid("%s:timeout waiting for response\n", __func__);
+		memset(response, 0, sizeof(struct hidpp_report));
+		return -ETIMEDOUT;
+	}
+
+	if (response->report_id == REPORT_ID_HIDPP_SHORT &&
+	    response->rap.sub_id == HIDPP_ERROR) {
+		ret = response->rap.params[1];
+		dbg_hid("%s:got hidpp error %02X\n", __func__, ret);
+		return ret;
+	}
+
+	if ((response->report_id == REPORT_ID_HIDPP_LONG ||
+	     response->report_id == REPORT_ID_HIDPP_VERY_LONG) &&
+	    response->fap.feature_index == HIDPP20_ERROR) {
+		ret = response->fap.params[1];
+		dbg_hid("%s:got hidpp 2.0 error %02X\n", __func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * hidpp_send_message_sync() returns 0 in case of success, and something else
+ * in case of a failure.
+ *
+ * See __do_hidpp_send_message_sync() for a detailed explanation of the returned
+ * value.
+ */
+static int hidpp_send_message_sync(struct hidpp_device *hidpp,
+	struct hidpp_report *message,
+	struct hidpp_report *response)
+{
+	int ret;
+	int max_retries = 3;
+
+	mutex_lock(&hidpp->send_mutex);
+
+	do {
+		ret = __do_hidpp_send_message_sync(hidpp, message, response);
+		if (ret != HIDPP20_ERROR_BUSY)
+			break;
+
+		dbg_hid("%s:got busy hidpp 2.0 error %02X, retrying\n", __func__, ret);
+	} while (--max_retries);
 
 	mutex_unlock(&hidpp->send_mutex);
 	return ret;
 
 }
 
+/*
+ * hidpp_send_fap_command_sync() returns 0 in case of success, and something else
+ * in case of a failure.
+ *
+ * See __do_hidpp_send_message_sync() for a detailed explanation of the returned
+ * value.
+ */
 static int hidpp_send_fap_command_sync(struct hidpp_device *hidpp,
 	u8 feat_index, u8 funcindex_clientid, u8 *params, int param_count,
 	struct hidpp_report *response)
···
 	return ret;
 }
 
+/*
+ * hidpp_send_rap_command_sync() returns 0 in case of success, and something else
+ * in case of a failure.
+ *
+ * See __do_hidpp_send_message_sync() for a detailed explanation of the returned
+ * value.
+ */
 static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
 	u8 report_id, u8 sub_id, u8 reg_address, u8 *params, int param_count,
 	struct hidpp_report *response)
···
 		.driver_data = HIDPP_QUIRK_CLASS_G920 | HIDPP_QUIRK_FORCE_OUTPUT_REPORTS },
 	{ /* Logitech G Pro Gaming Mouse over USB */
 	  HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, 0xC088) },
+	{ /* Logitech G Pro X Superlight Gaming Mouse over USB */
+	  HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, 0xC094) },
 
 	{ /* G935 Gaming Headset */
 	  HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, 0x0a87),
···
 	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb02a) },
 	{ /* MX Master 3 mouse over Bluetooth */
 	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb023) },
+	{ /* MX Anywhere 3 mouse over Bluetooth */
+	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb025) },
 	{ /* MX Master 3S mouse over Bluetooth */
 	  HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH, 0xb034) },
 	{}

drivers/hid/hid-multitouch.c

···
 static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
 {
 	struct mt_device *td = hid_get_drvdata(hdev);
-	char *name;
 	const char *suffix = NULL;
 	struct mt_report_data *rdata;
 	struct mt_application *mt_application = NULL;
···
 		break;
 	}
 
-	if (suffix) {
-		name = devm_kzalloc(&hi->input->dev,
-				    strlen(hdev->name) + strlen(suffix) + 2,
-				    GFP_KERNEL);
-		if (name) {
-			sprintf(name, "%s %s", hdev->name, suffix);
-			hi->input->name = name;
-		}
-	}
+	if (suffix)
+		hi->input->name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
+						 "%s %s", hdev->name, suffix);
 
 	return 0;
 }

drivers/hid/hid-nvidia-shield.c

···
  */
 
 #include <linux/hid.h>
+#include <linux/idr.h>
 #include <linux/input-event-codes.h>
 #include <linux/input.h>
+#include <linux/jiffies.h>
 #include <linux/leds.h>
 #include <linux/module.h>
+#include <linux/power_supply.h>
 #include <linux/spinlock.h>
+#include <linux/timer.h>
 #include <linux/workqueue.h>
 
 #include "hid-ids.h"
···
 enum {
 	SHIELD_FW_VERSION_INITIALIZED = 0,
 	SHIELD_BOARD_INFO_INITIALIZED,
+	SHIELD_BATTERY_STATS_INITIALIZED,
+	SHIELD_CHARGER_STATE_INITIALIZED,
 };
 
 enum {
···
 	THUNDERSTRIKE_BOARD_INFO_UPDATE,
 	THUNDERSTRIKE_HAPTICS_UPDATE,
 	THUNDERSTRIKE_LED_UPDATE,
+	THUNDERSTRIKE_POWER_SUPPLY_STATS_UPDATE,
 };
 
 enum {
···
 enum {
 	THUNDERSTRIKE_HOSTCMD_ID_FW_VERSION = 1,
 	THUNDERSTRIKE_HOSTCMD_ID_LED = 6,
+	THUNDERSTRIKE_HOSTCMD_ID_BATTERY,
 	THUNDERSTRIKE_HOSTCMD_ID_BOARD_INFO = 16,
 	THUNDERSTRIKE_HOSTCMD_ID_USB_INIT = 53,
 	THUNDERSTRIKE_HOSTCMD_ID_HAPTICS = 57,
-	THUNDERSTRIKE_HOSTCMD_ID_BLUETOOTH_INIT = 58,
+	THUNDERSTRIKE_HOSTCMD_ID_CHARGER,
+};
+
+struct power_supply_dev {
+	struct power_supply *psy;
+	struct power_supply_desc desc;
+};
+
+struct thunderstrike_psy_prop_values {
+	int voltage_min;
+	int voltage_now;
+	int voltage_avg;
+	int voltage_boot;
+	int capacity;
+	int status;
+	int charge_type;
+	int temp;
+};
+
+static const enum power_supply_property thunderstrike_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_AVG,
+	POWER_SUPPLY_PROP_VOLTAGE_BOOT,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_SCOPE,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_TEMP_MIN,
+	POWER_SUPPLY_PROP_TEMP_MAX,
+	POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
+	POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
 };
 
 enum thunderstrike_led_state {
···
 	THUNDERSTRIKE_LED_ON = 8,
 } __packed;
 static_assert(sizeof(enum thunderstrike_led_state) == 1);
+
+struct thunderstrike_hostcmd_battery {
+	__le16 voltage_avg;
+	u8 reserved_at_10;
+	__le16 thermistor;
+	__le16 voltage_min;
+	__le16 voltage_boot;
+	__le16 voltage_now;
+	u8 capacity;
+} __packed;
+
+enum thunderstrike_charger_type {
+	THUNDERSTRIKE_CHARGER_TYPE_NONE = 0,
+	THUNDERSTRIKE_CHARGER_TYPE_TRICKLE,
+	THUNDERSTRIKE_CHARGER_TYPE_NORMAL,
+} __packed;
+static_assert(sizeof(enum thunderstrike_charger_type) == 1);
+
+enum thunderstrike_charger_state {
+	THUNDERSTRIKE_CHARGER_STATE_UNKNOWN = 0,
+	THUNDERSTRIKE_CHARGER_STATE_DISABLED,
+	THUNDERSTRIKE_CHARGER_STATE_CHARGING,
+	THUNDERSTRIKE_CHARGER_STATE_FULL,
+	THUNDERSTRIKE_CHARGER_STATE_FAILED = 8,
+} __packed;
+static_assert(sizeof(enum thunderstrike_charger_state) == 1);
+
+struct thunderstrike_hostcmd_charger {
+	u8 connected;
+	enum thunderstrike_charger_type type;
+	enum thunderstrike_charger_state state;
+} __packed;
 
 struct thunderstrike_hostcmd_board_info {
 	__le16 revision;
···
 		struct thunderstrike_hostcmd_haptics motors;
 		__le16 fw_version;
 		enum thunderstrike_led_state led_state;
+		struct thunderstrike_hostcmd_battery battery;
+		struct thunderstrike_hostcmd_charger charger;
 		u8 payload[30];
 	} __packed;
 } __packed;
···
 /* Common struct for shield accessories. */
 struct shield_device {
 	struct hid_device *hdev;
+	struct power_supply_dev battery_dev;
 
 	unsigned long initialized_flags;
 	const char *codename;
···
 	} board_info;
 };
 
+/*
+ * Non-trivial to uniquely identify Thunderstrike controllers at initialization
+ * time. Use an ID allocator to help with this.
+ */
+static DEFINE_IDA(thunderstrike_ida);
+
 struct thunderstrike {
 	struct shield_device base;
+
+	int id;
 
 	/* Sub-devices */
 	struct input_dev *haptics_dev;
···
 	spinlock_t haptics_update_lock;
 	u8 led_state : 1;
 	enum thunderstrike_led_state led_value;
+	struct thunderstrike_psy_prop_values psy_stats;
+	spinlock_t psy_stats_lock;
+	struct timer_list psy_stats_timer;
 	struct work_struct hostcmd_req_work;
 };
 
···
 	idev->id.product = hdev->product;
 	idev->id.version = hdev->version;
 	idev->uniq = hdev->uniq;
-	idev->name = devm_kasprintf(&idev->dev, GFP_KERNEL, "%s %s", hdev->name,
+	idev->name = devm_kasprintf(&hdev->dev, GFP_KERNEL, "%s %s", hdev->name,
 				    name_suffix);
 	if (!idev->name)
 		goto err_name;
···
 		thunderstrike_hostcmd_req_report_init(report, THUNDERSTRIKE_HOSTCMD_ID_LED);
 		report->led.update = 1;
 		report->led.state = ts->led_value;
+		thunderstrike_send_hostcmd_request(ts);
+	}
+
+	if (test_and_clear_bit(THUNDERSTRIKE_POWER_SUPPLY_STATS_UPDATE, &ts->update_flags)) {
+		thunderstrike_hostcmd_req_report_init(
+			report, THUNDERSTRIKE_HOSTCMD_ID_BATTERY);
+		thunderstrike_send_hostcmd_request(ts);
+
+		thunderstrike_hostcmd_req_report_init(
+			report, THUNDERSTRIKE_HOSTCMD_ID_CHARGER);
 		thunderstrike_send_hostcmd_request(ts);
 	}
 
···
 	schedule_work(&ts->hostcmd_req_work);
 }
 
+static int thunderstrike_battery_get_property(struct power_supply *psy,
+					      enum power_supply_property psp,
+					      union power_supply_propval *val)
+{
+	struct shield_device *shield_dev = power_supply_get_drvdata(psy);
+	struct thunderstrike_psy_prop_values prop_values;
+	struct thunderstrike *ts;
+	int ret = 0;
+
+	ts = container_of(shield_dev, struct thunderstrike, base);
+	spin_lock(&ts->psy_stats_lock);
+	prop_values = ts->psy_stats;
+	spin_unlock(&ts->psy_stats_lock);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = prop_values.status;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		val->intval = prop_values.charge_type;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN:
+		val->intval = prop_values.voltage_min;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = 2900000; /* 2.9 V */
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = 2200000; /* 2.2 V */
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = prop_values.voltage_now;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+		val->intval = prop_values.voltage_avg;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_BOOT:
+		val->intval = prop_values.voltage_boot;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		val->intval = prop_values.capacity;
+		break;
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_DEVICE;
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval = prop_values.temp;
+		break;
+	case POWER_SUPPLY_PROP_TEMP_MIN:
+		val->intval = 0; /* 0 C */
+		break;
+	case POWER_SUPPLY_PROP_TEMP_MAX:
+		val->intval = 400; /* 40 C */
+		break;
+	case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+		val->intval = 15; /* 1.5 C */
+		break;
+	case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+		val->intval = 380; /* 38 C */
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static inline void thunderstrike_request_psy_stats(struct thunderstrike *ts)
+{
+	set_bit(THUNDERSTRIKE_POWER_SUPPLY_STATS_UPDATE, &ts->update_flags);
+	schedule_work(&ts->hostcmd_req_work);
+}
+
+static void thunderstrike_psy_stats_timer_handler(struct timer_list *timer)
+{
+	struct thunderstrike *ts =
+		container_of(timer, struct thunderstrike, psy_stats_timer);
+
+	thunderstrike_request_psy_stats(ts);
+	/* Query battery statistics from device every five minutes */
+	mod_timer(timer, jiffies + 300 * HZ);
+}
+
 static void
 thunderstrike_parse_fw_version_payload(struct shield_device *shield_dev,
 				       __le16 fw_version)
···
 	hid_dbg(shield_dev->hdev, "Thunderstrike led HOSTCMD response, 0x%02X\n", led_state);
 }
 
+static void thunderstrike_parse_battery_payload(
+	struct shield_device *shield_dev,
+	struct thunderstrike_hostcmd_battery *battery)
+{
+	struct thunderstrike *ts = container_of(shield_dev, struct thunderstrike, base);
+	u16 hostcmd_voltage_boot = le16_to_cpu(battery->voltage_boot);
+	u16 hostcmd_voltage_avg = le16_to_cpu(battery->voltage_avg);
+	u16 hostcmd_voltage_min = le16_to_cpu(battery->voltage_min);
+	u16 hostcmd_voltage_now = le16_to_cpu(battery->voltage_now);
+	u16 hostcmd_thermistor = le16_to_cpu(battery->thermistor);
+	int voltage_boot, voltage_avg, voltage_min, voltage_now;
+	struct hid_device *hdev = shield_dev->hdev;
+	u8 capacity = battery->capacity;
+	int temp;
+
+	/* Convert thunderstrike device values to µV and tenths of degree Celsius */
+	voltage_boot = hostcmd_voltage_boot * 1000;
+	voltage_avg = hostcmd_voltage_avg * 1000;
+	voltage_min = hostcmd_voltage_min * 1000;
+	voltage_now = hostcmd_voltage_now * 1000;
+	temp = (1378 - (int)hostcmd_thermistor) * 10 / 19;
+
+	/* Copy converted values */
+	spin_lock(&ts->psy_stats_lock);
+	ts->psy_stats.voltage_boot = voltage_boot;
+	ts->psy_stats.voltage_avg = voltage_avg;
+	ts->psy_stats.voltage_min = voltage_min;
+	ts->psy_stats.voltage_now = voltage_now;
+	ts->psy_stats.capacity = capacity;
+	ts->psy_stats.temp = temp;
+	spin_unlock(&ts->psy_stats_lock);
+
+	set_bit(SHIELD_BATTERY_STATS_INITIALIZED, &shield_dev->initialized_flags);
+
+	hid_dbg(hdev,
+		"Thunderstrike battery HOSTCMD response, voltage_avg: %u voltage_now: %u\n",
+		hostcmd_voltage_avg, hostcmd_voltage_now);
+	hid_dbg(hdev,
+		"Thunderstrike battery HOSTCMD response, voltage_boot: %u voltage_min: %u\n",
+		hostcmd_voltage_boot, hostcmd_voltage_min);
+	hid_dbg(hdev,
+		"Thunderstrike battery HOSTCMD response, thermistor: %u\n",
+		hostcmd_thermistor);
+	hid_dbg(hdev,
+		"Thunderstrike battery HOSTCMD response, capacity: %u%%\n",
+		capacity);
+}
+
+static void thunderstrike_parse_charger_payload(
+	struct shield_device *shield_dev,
+	struct thunderstrike_hostcmd_charger *charger)
+{
+	struct thunderstrike *ts = container_of(shield_dev, struct thunderstrike, base);
+	int charge_type = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+	struct hid_device *hdev = shield_dev->hdev;
+	int status = POWER_SUPPLY_STATUS_UNKNOWN;
+
+	switch (charger->type) {
+	case THUNDERSTRIKE_CHARGER_TYPE_NONE:
+		charge_type = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		break;
+	case THUNDERSTRIKE_CHARGER_TYPE_TRICKLE:
+		charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+		break;
+	case THUNDERSTRIKE_CHARGER_TYPE_NORMAL:
+		charge_type = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+		break;
+	default:
+		hid_warn(hdev, "Unhandled Thunderstrike charger HOSTCMD type, %u\n",
+			 charger->type);
+		break;
+	}
+
+	switch (charger->state) {
+	case THUNDERSTRIKE_CHARGER_STATE_UNKNOWN:
+		status = POWER_SUPPLY_STATUS_UNKNOWN;
+		break;
+	case THUNDERSTRIKE_CHARGER_STATE_DISABLED:
+		/* Indicates charger is disconnected */
+		break;
+	case THUNDERSTRIKE_CHARGER_STATE_CHARGING:
+		status = POWER_SUPPLY_STATUS_CHARGING;
+		break;
+	case THUNDERSTRIKE_CHARGER_STATE_FULL:
+		status = POWER_SUPPLY_STATUS_FULL;
+		break;
+	case THUNDERSTRIKE_CHARGER_STATE_FAILED:
+		status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		hid_err(hdev, "Thunderstrike device failed to charge\n");
+		break;
+	default:
+		hid_warn(hdev, "Unhandled Thunderstrike charger HOSTCMD state, %u\n",
+			 charger->state);
+		break;
+	}
+
+	if (!charger->connected)
+		status = POWER_SUPPLY_STATUS_DISCHARGING;
+
+	spin_lock(&ts->psy_stats_lock);
+	ts->psy_stats.charge_type = charge_type;
+	ts->psy_stats.status = status;
+	spin_unlock(&ts->psy_stats_lock);
+
+	set_bit(SHIELD_CHARGER_STATE_INITIALIZED, &shield_dev->initialized_flags);
+
+	hid_dbg(hdev,
+		"Thunderstrike charger HOSTCMD response, connected: %u, type: %u, state: %u\n",
+		charger->connected, charger->type, charger->state);
+}
+
+static inline void thunderstrike_device_init_info(struct shield_device *shield_dev)
+{
+	struct thunderstrike *ts =
+		container_of(shield_dev, struct thunderstrike, base);
+
+	if (!test_bit(SHIELD_FW_VERSION_INITIALIZED, &shield_dev->initialized_flags))
+		thunderstrike_request_firmware_version(ts);
+
+	if (!test_bit(SHIELD_BOARD_INFO_INITIALIZED, &shield_dev->initialized_flags))
+		thunderstrike_request_board_info(ts);
+
+	if (!test_bit(SHIELD_BATTERY_STATS_INITIALIZED, &shield_dev->initialized_flags) ||
+	    !test_bit(SHIELD_CHARGER_STATE_INITIALIZED, &shield_dev->initialized_flags))
+		thunderstrike_psy_stats_timer_handler(&ts->psy_stats_timer);
+}
+
 static int thunderstrike_parse_report(struct shield_device *shield_dev,
 				      struct hid_report *report, u8 *data,
 				      int size)
 {
 	struct thunderstrike_hostcmd_resp_report *hostcmd_resp_report;
-	struct thunderstrike *ts =
-		container_of(shield_dev, struct thunderstrike, base);
 	struct hid_device *hdev = shield_dev->hdev;
 
 	switch (report->id) {
···
 		case THUNDERSTRIKE_HOSTCMD_ID_LED:
 			thunderstrike_parse_led_payload(shield_dev, hostcmd_resp_report->led_state);
 			break;
+		case THUNDERSTRIKE_HOSTCMD_ID_BATTERY:
+			thunderstrike_parse_battery_payload(shield_dev,
+							    &hostcmd_resp_report->battery);
+			break;
 		case THUNDERSTRIKE_HOSTCMD_ID_BOARD_INFO:
 			thunderstrike_parse_board_info_payload(
 				shield_dev, &hostcmd_resp_report->board_info);
···
 			thunderstrike_parse_haptics_payload(
 				shield_dev, &hostcmd_resp_report->motors);
 			break;
-
 		case THUNDERSTRIKE_HOSTCMD_ID_USB_INIT:
-		case THUNDERSTRIKE_HOSTCMD_ID_BLUETOOTH_INIT:
 			/* May block HOSTCMD requests till received initially */
-			thunderstrike_request_firmware_version(ts);
-			thunderstrike_request_board_info(ts);
-			/* Only HOSTCMD that can be triggered without a request */
-			return 0;
+			thunderstrike_device_init_info(shield_dev);
+			break;
+		case THUNDERSTRIKE_HOSTCMD_ID_CHARGER:
+			/* May block HOSTCMD requests till received initially */
+			thunderstrike_device_init_info(shield_dev);
+
+			thunderstrike_parse_charger_payload(
+				shield_dev, &hostcmd_resp_report->charger);
+			break;
 		default:
 			hid_warn(hdev,
 				 "Unhandled Thunderstrike HOSTCMD id %d\n",
···
 {
 	struct led_classdev *led = &ts->led_dev;
 
-	led->name = "thunderstrike:blue:led";
+	led->name = devm_kasprintf(&ts->base.hdev->dev, GFP_KERNEL,
+				   "thunderstrike%d:blue:led", ts->id);
 	led->max_brightness = 1;
 	led->flags = LED_CORE_SUSPENDRESUME;
 	led->brightness_get = &thunderstrike_led_get_brightness;
 	led->brightness_set = &thunderstrike_led_set_brightness;
 
 	return led_classdev_register(&ts->base.hdev->dev, led);
+}
+
+static inline int thunderstrike_psy_create(struct shield_device *shield_dev)
+{
+	struct thunderstrike *ts = container_of(shield_dev, struct thunderstrike, base);
+	struct power_supply_config psy_cfg = { .drv_data = shield_dev, };
+	struct hid_device *hdev = shield_dev->hdev;
+	int ret;
+
+	/*
+	 * Set an initial capacity and temperature value to avoid prematurely
+	 * triggering alerts. Will be replaced by values queried from initial
+	 * HOSTCMD requests.
+	 */
+	ts->psy_stats.capacity = 100;
+	ts->psy_stats.temp = 182;
+
+	shield_dev->battery_dev.desc.properties = thunderstrike_battery_props;
+	shield_dev->battery_dev.desc.num_properties =
+		ARRAY_SIZE(thunderstrike_battery_props);
+	shield_dev->battery_dev.desc.get_property = thunderstrike_battery_get_property;
+	shield_dev->battery_dev.desc.type = POWER_SUPPLY_TYPE_BATTERY;
+	shield_dev->battery_dev.desc.name =
+		devm_kasprintf(&ts->base.hdev->dev, GFP_KERNEL,
+			       "thunderstrike_%d", ts->id);
+
+	shield_dev->battery_dev.psy = power_supply_register(
+		&hdev->dev, &shield_dev->battery_dev.desc, &psy_cfg);
+	if (IS_ERR(shield_dev->battery_dev.psy)) {
+		hid_err(hdev, "Failed to register Thunderstrike battery device\n");
+		return PTR_ERR(shield_dev->battery_dev.psy);
+	}
+
+	ret = power_supply_powers(shield_dev->battery_dev.psy, &hdev->dev);
+	if (ret) {
+		hid_err(hdev, "Failed to associate battery device to Thunderstrike\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	power_supply_unregister(shield_dev->battery_dev.psy);
+	return ret;
 }
 
 static struct shield_device *thunderstrike_create(struct hid_device *hdev)
···
 	shield_dev->codename = "Thunderstrike";
 
 	spin_lock_init(&ts->haptics_update_lock);
+	spin_lock_init(&ts->psy_stats_lock);
 	INIT_WORK(&ts->hostcmd_req_work, thunderstrike_hostcmd_req_work_handler);
 
 	hid_set_drvdata(hdev, shield_dev);
 
+	ts->id = ida_alloc(&thunderstrike_ida, GFP_KERNEL);
+	if (ts->id < 0)
+		return ERR_PTR(ts->id);
+
+	ts->haptics_dev = shield_haptics_create(shield_dev, thunderstrike_play_effect);
+	if (IS_ERR(ts->haptics_dev)) {
+		hid_err(hdev, "Failed to create Thunderstrike haptics instance\n");
+		ret = PTR_ERR(ts->haptics_dev);
+		goto err_id;
+	}
+
+	ret = thunderstrike_psy_create(shield_dev);
+	if (ret) {
+		hid_err(hdev, "Failed to create Thunderstrike power supply instance\n");
+		goto err_haptics;
+	}
+
 	ret = thunderstrike_led_create(ts);
 	if (ret) {
 		hid_err(hdev, "Failed to create Thunderstrike LED instance\n");
-		return ERR_PTR(ret);
+		goto err_psy;
 	}
 
-	ts->haptics_dev = shield_haptics_create(shield_dev, thunderstrike_play_effect);
-	if (IS_ERR(ts->haptics_dev))
-		goto err;
+	timer_setup(&ts->psy_stats_timer, thunderstrike_psy_stats_timer_handler, 0);
 
 	hid_info(hdev, "Registered Thunderstrike controller\n");
 	return shield_dev;
 
-err:
-	led_classdev_unregister(&ts->led_dev);
-	return ERR_CAST(ts->haptics_dev);
+err_psy:
+	power_supply_unregister(shield_dev->battery_dev.psy);
+err_haptics:
+	if (ts->haptics_dev)
+		input_unregister_device(ts->haptics_dev);
+err_id:
+	ida_free(&thunderstrike_ida, ts->id);
+	return ERR_PTR(ret);
 }
 
 static int android_input_mapping(struct hid_device *hdev, struct hid_input *hi,
···
 		goto err_stop;
 	}
 
-	thunderstrike_request_firmware_version(ts);
-	thunderstrike_request_board_info(ts);
+	thunderstrike_device_init_info(shield_dev);
 
 	return ret;
 
···
 	ts = container_of(dev, struct thunderstrike, base);
 
 	hid_hw_close(hdev);
-	led_classdev_unregister(&ts->led_dev);
+	power_supply_unregister(dev->battery_dev.psy);
 	if (ts->haptics_dev)
 		input_unregister_device(ts->haptics_dev);
+	led_classdev_unregister(&ts->led_dev);
+	ida_free(&thunderstrike_ida, ts->id);
+	del_timer_sync(&ts->psy_stats_timer);
 	cancel_work_sync(&ts->hostcmd_req_work);
 	hid_hw_stop(hdev);
 }

drivers/hid/hid-sensor-hub.c

···
 	}
 	INIT_LIST_HEAD(&hdev->inputs);
 
-	ret = hid_hw_start(hdev, 0);
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 	if (ret) {
 		hid_err(hdev, "hw start failed\n");
 		return ret;

drivers/hid/hid-steelseries.c

···
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
- *  HID driver for Steelseries SRW-S1
+ *  HID driver for Steelseries devices
  *
  *  Copyright (c) 2013 Simon Wood
+ *  Copyright (c) 2023 Bastien Nocera
  */
 
 /*
···
 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/module.h>
+#include <linux/usb.h>
 #include <linux/leds.h>
 
 #include "hid-ids.h"
+
+#define STEELSERIES_SRWS1		BIT(0)
+#define STEELSERIES_ARCTIS_1		BIT(1)
+
+struct steelseries_device {
+	struct hid_device *hdev;
+	unsigned long quirks;
+
+	struct delayed_work battery_work;
+	spinlock_t lock;
+	bool removed;
+
+	struct power_supply_desc battery_desc;
+	struct power_supply *battery;
+	uint8_t battery_capacity;
+	bool headset_connected;
+};
 
 #if IS_BUILTIN(CONFIG_LEDS_CLASS) || \
     (IS_MODULE(CONFIG_LEDS_CLASS) && IS_MODULE(CONFIG_HID_STEELSERIES))
···
 }
 #endif
 
+#define STEELSERIES_HEADSET_BATTERY_TIMEOUT_MS	3000
+
+#define ARCTIS_1_BATTERY_RESPONSE_LEN		8
+static const char arctis_1_battery_request[] = { 0x06, 0x12 };
+
+static int steelseries_headset_arctis_1_fetch_battery(struct hid_device *hdev)
+{
+	u8 *write_buf;
+	int ret;
+
+	/* Request battery information */
+	write_buf = kmemdup(arctis_1_battery_request, sizeof(arctis_1_battery_request), GFP_KERNEL);
+	if (!write_buf)
+		return -ENOMEM;
+
+	ret = hid_hw_raw_request(hdev, arctis_1_battery_request[0],
+				 write_buf, sizeof(arctis_1_battery_request),
+				 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
+	if (ret < sizeof(arctis_1_battery_request)) {
+		hid_err(hdev, "hid_hw_raw_request() failed with %d\n", ret);
+		ret = -ENODATA;
+	}
+	kfree(write_buf);
+	return ret;
+}
+
+static void steelseries_headset_fetch_battery(struct hid_device *hdev)
+{
+	struct steelseries_device *sd = hid_get_drvdata(hdev);
+	int ret = 0;
+
+	if (sd->quirks & STEELSERIES_ARCTIS_1)
+		ret = steelseries_headset_arctis_1_fetch_battery(hdev);
+
+	if (ret < 0)
+		hid_dbg(hdev,
+			"Battery query failed (err: %d)\n", ret);
+}
+
+static void steelseries_headset_battery_timer_tick(struct work_struct *work)
+{
+	struct steelseries_device *sd = container_of(work,
+		struct steelseries_device, battery_work.work);
+	struct hid_device *hdev = sd->hdev;
+
+	steelseries_headset_fetch_battery(hdev);
+}
+
+static int steelseries_headset_battery_get_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct steelseries_device *sd = power_supply_get_drvdata(psy);
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		val->intval = sd->headset_connected ?
+			POWER_SUPPLY_STATUS_DISCHARGING :
+			POWER_SUPPLY_STATUS_UNKNOWN;
+		break;
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_DEVICE;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		val->intval = sd->battery_capacity;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
+}
+
+static void
+steelseries_headset_set_wireless_status(struct hid_device *hdev,
+					bool connected)
+{
+	struct usb_interface *intf;
+
+	if (!hid_is_usb(hdev))
+		return;
+
+	intf = to_usb_interface(hdev->dev.parent);
+	usb_set_wireless_status(intf, connected ?
+				USB_WIRELESS_STATUS_CONNECTED :
+				USB_WIRELESS_STATUS_DISCONNECTED);
+}
+
+static enum power_supply_property steelseries_headset_battery_props[] = {
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_SCOPE,
+	POWER_SUPPLY_PROP_CAPACITY,
+};
+
+static int steelseries_headset_battery_register(struct steelseries_device *sd)
+{
+	static atomic_t battery_no = ATOMIC_INIT(0);
+	struct power_supply_config battery_cfg = { .drv_data = sd, };
+	unsigned long n;
+	int ret;
+
+	sd->battery_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+	sd->battery_desc.properties = steelseries_headset_battery_props;
+	sd->battery_desc.num_properties = ARRAY_SIZE(steelseries_headset_battery_props);
+	sd->battery_desc.get_property = steelseries_headset_battery_get_property;
+	sd->battery_desc.use_for_apm = 0;
+	n = atomic_inc_return(&battery_no) - 1;
+	sd->battery_desc.name = devm_kasprintf(&sd->hdev->dev, GFP_KERNEL,
+						    "steelseries_headset_battery_%ld", n);
+	if (!sd->battery_desc.name)
+		return -ENOMEM;
+
+	/* avoid the warning of 0% battery while waiting for the first info */
+	steelseries_headset_set_wireless_status(sd->hdev, false);
+	sd->battery_capacity = 100;
+
+	sd->battery = devm_power_supply_register(&sd->hdev->dev,
+			&sd->battery_desc, &battery_cfg);
+	if (IS_ERR(sd->battery)) {
+		ret = PTR_ERR(sd->battery);
+		hid_err(sd->hdev,
+				"%s:power_supply_register failed with error %d\n",
+				__func__, ret);
+		return ret;
+	}
+	power_supply_powers(sd->battery, &sd->hdev->dev);
+
+	INIT_DELAYED_WORK(&sd->battery_work, steelseries_headset_battery_timer_tick);
+	steelseries_headset_fetch_battery(sd->hdev);
+
+	return 0;
+}
+
+static int steelseries_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct steelseries_device *sd;
+	int ret;
+
+	sd = devm_kzalloc(&hdev->dev, sizeof(*sd), GFP_KERNEL);
+	if (!sd)
+		return -ENOMEM;
+	hid_set_drvdata(hdev, sd);
+	sd->hdev = hdev;
+	sd->quirks = id->driver_data;
+
+	if (sd->quirks & STEELSERIES_SRWS1) {
+#if IS_BUILTIN(CONFIG_LEDS_CLASS) || \
+    (IS_MODULE(CONFIG_LEDS_CLASS) && IS_MODULE(CONFIG_HID_STEELSERIES))
+		return steelseries_srws1_probe(hdev, id);
+#else
+		return -ENODEV;
+#endif
+	}
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&sd->lock);
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret)
+		return ret;
+
+	if (steelseries_headset_battery_register(sd) < 0)
+		hid_err(sd->hdev,
+			"Failed to register battery for headset\n");
+
+	return ret;
+}
+
+static void steelseries_remove(struct hid_device *hdev)
+{
+	struct steelseries_device *sd = hid_get_drvdata(hdev);
+	unsigned long flags;
+
+	if (sd->quirks & STEELSERIES_SRWS1) {
+#if IS_BUILTIN(CONFIG_LEDS_CLASS) || \
+    (IS_MODULE(CONFIG_LEDS_CLASS) && IS_MODULE(CONFIG_HID_STEELSERIES))
+		steelseries_srws1_remove(hdev);
+#endif
+		return;
+	}
+
+	spin_lock_irqsave(&sd->lock, flags);
+	sd->removed = true;
+	spin_unlock_irqrestore(&sd->lock, flags);
+
+	cancel_delayed_work_sync(&sd->battery_work);
+
+	hid_hw_stop(hdev);
+}
+
 static __u8 *steelseries_srws1_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		unsigned int *rsize)
 {
+	if (hdev->vendor != USB_VENDOR_ID_STEELSERIES ||
+	    hdev->product != USB_DEVICE_ID_STEELSERIES_SRWS1)
+		return rdesc;
+
 	if (*rsize >= 115 && rdesc[11] == 0x02 && rdesc[13] == 0xc8
 			&& rdesc[29] == 0xbb && rdesc[40] == 0xc5) {
 		hid_info(hdev, "Fixing up Steelseries SRW-S1 report descriptor\n");
···
 	return rdesc;
 }
 
-static const struct hid_device_id steelseries_srws1_devices[] = {
-	{ HID_USB_DEVICE(USB_VENDOR_ID_STEELSERIES, USB_DEVICE_ID_STEELSERIES_SRWS1) },
+static int steelseries_headset_raw_event(struct hid_device *hdev,
+					struct hid_report *report, u8 *read_buf,
+					int size)
+{
+	struct steelseries_device *sd = hid_get_drvdata(hdev);
+	int capacity = sd->battery_capacity;
+	bool connected = sd->headset_connected;
+	unsigned long flags;
+
+	/* Not a headset */
+	if (sd->quirks & STEELSERIES_SRWS1)
+		return 0;
+
+	if (sd->quirks & STEELSERIES_ARCTIS_1) {
+		hid_dbg(sd->hdev,
+			"Parsing raw event for Arctis 1 headset (%*ph)\n", size, read_buf);
+		if (size < ARCTIS_1_BATTERY_RESPONSE_LEN ||
+		    memcmp (read_buf, arctis_1_battery_request, sizeof(arctis_1_battery_request)))
+			return 0;
+		if (read_buf[2] == 0x01) {
+			connected = false;
+			capacity = 100;
+		} else {
+			connected = true;
+			capacity = read_buf[3];
+		}
+	}
+
+	if (connected != sd->headset_connected) {
+		hid_dbg(sd->hdev,
+			"Connected status changed from %sconnected to %sconnected\n",
+			sd->headset_connected ? "" : "not ",
+			connected ? "" : "not ");
+		sd->headset_connected = connected;
+		steelseries_headset_set_wireless_status(hdev, connected);
+	}
+
+	if (capacity != sd->battery_capacity) {
+		hid_dbg(sd->hdev,
+			"Battery capacity changed from %d%% to %d%%\n",
+			sd->battery_capacity, capacity);
+		sd->battery_capacity = capacity;
+		power_supply_changed(sd->battery);
+	}
+
+	spin_lock_irqsave(&sd->lock, flags);
+	if (!sd->removed)
+		schedule_delayed_work(&sd->battery_work,
+				msecs_to_jiffies(STEELSERIES_HEADSET_BATTERY_TIMEOUT_MS));
+	spin_unlock_irqrestore(&sd->lock, flags);
+
+	return 0;
+}
+
+static const struct hid_device_id steelseries_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_STEELSERIES, USB_DEVICE_ID_STEELSERIES_SRWS1),
+	  .driver_data = STEELSERIES_SRWS1 },
+
+	{ /* SteelSeries Arctis 1 Wireless for XBox */
+	  HID_USB_DEVICE(USB_VENDOR_ID_STEELSERIES, 0x12b6),
+	.driver_data = STEELSERIES_ARCTIS_1 },
+
 	{ }
 };
-MODULE_DEVICE_TABLE(hid, steelseries_srws1_devices);
+MODULE_DEVICE_TABLE(hid, steelseries_devices);
 
-static struct hid_driver steelseries_srws1_driver = {
-	.name = "steelseries_srws1",
-	.id_table = steelseries_srws1_devices,
-#if IS_BUILTIN(CONFIG_LEDS_CLASS) || \
-    (IS_MODULE(CONFIG_LEDS_CLASS) && IS_MODULE(CONFIG_HID_STEELSERIES))
-	.probe = steelseries_srws1_probe,
-	.remove = steelseries_srws1_remove,
-#endif
-	.report_fixup = steelseries_srws1_report_fixup
+static struct hid_driver steelseries_driver = {
+	.name = "steelseries",
+	.id_table = steelseries_devices,
+	.probe = steelseries_probe,
+	.remove = steelseries_remove,
+	.report_fixup = steelseries_srws1_report_fixup,
+	.raw_event = steelseries_headset_raw_event,
 };
 
-module_hid_driver(steelseries_srws1_driver);
+module_hid_driver(steelseries_driver);
 MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Bastien Nocera <[e-mail]>");
+MODULE_AUTHOR("Simon Wood <[e-mail]>");

drivers/hid/hid-uclogic-core.c

···
 {
 	struct uclogic_drvdata *drvdata = hid_get_drvdata(hdev);
 	struct uclogic_params *params = &drvdata->params;
-	char *name;
 	const char *suffix = NULL;
 	struct hid_field *field;
-	size_t len;
 	size_t i;
 	const struct uclogic_params_frame *frame;
 
···
 		}
 	}
 
-	if (suffix) {
-		len = strlen(hdev->name) + 2 + strlen(suffix);
-		name = devm_kzalloc(&hi->input->dev, len, GFP_KERNEL);
-		if (name) {
-			snprintf(name, len, "%s %s", hdev->name, suffix);
-			hi->input->name = name;
-		}
-	}
+	if (suffix)
+		hi->input->name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
+						 "%s %s", hdev->name, suffix);
 
 	return 0;
 }

drivers/hid/hid-wiimote-debug.c

···
 {
 	struct wiimote_debug *dbg;
 	unsigned long flags;
-	int ret = -ENOMEM;
 
 	dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
 	if (!dbg)
···
 
 	dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
 		dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);
-	if (!dbg->eeprom)
-		goto err;
 
 	dbg->drm = debugfs_create_file("drm", S_IRUSR,
 			dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);
-	if (!dbg->drm)
-		goto err_drm;
 
 	spin_lock_irqsave(&wdata->state.lock, flags);
 	wdata->debug = dbg;
···
 
 	return 0;
 
-err_drm:
-	debugfs_remove(dbg->eeprom);
-err:
-	kfree(dbg);
-	return ret;
 }
 
 void wiidebug_deinit(struct wiimote_data *wdata)

drivers/hid/i2c-hid/i2c-hid-of-elan.c

···
 #include "i2c-hid.h"
 
 struct elan_i2c_hid_chip_data {
-	unsigned int post_gpio_reset_delay_ms;
+	unsigned int post_gpio_reset_on_delay_ms;
+	unsigned int post_gpio_reset_off_delay_ms;
 	unsigned int post_power_delay_ms;
 	u16 hid_descriptor_address;
+	const char *main_supply_name;
 };
 
 struct i2c_hid_of_elan {
···
 		container_of(ops, struct i2c_hid_of_elan, ops);
 	int ret;
 
-	ret = regulator_enable(ihid_elan->vcc33);
-	if (ret)
-		return ret;
+	if (ihid_elan->vcc33) {
+		ret = regulator_enable(ihid_elan->vcc33);
+		if (ret)
+			return ret;
+	}
 
 	ret = regulator_enable(ihid_elan->vccio);
 	if (ret) {
···
 		msleep(ihid_elan->chip_data->post_power_delay_ms);
 
 	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 0);
-	if (ihid_elan->chip_data->post_gpio_reset_delay_ms)
-		msleep(ihid_elan->chip_data->post_gpio_reset_delay_ms);
+	if (ihid_elan->chip_data->post_gpio_reset_on_delay_ms)
+		msleep(ihid_elan->chip_data->post_gpio_reset_on_delay_ms);
 
 	return 0;
 }
···
 		container_of(ops, struct i2c_hid_of_elan, ops);
 
 	gpiod_set_value_cansleep(ihid_elan->reset_gpio, 1);
+	if (ihid_elan->chip_data->post_gpio_reset_off_delay_ms)
+		msleep(ihid_elan->chip_data->post_gpio_reset_off_delay_ms);
+
 	regulator_disable(ihid_elan->vccio);
-	regulator_disable(ihid_elan->vcc33);
+	if (ihid_elan->vcc33)
+		regulator_disable(ihid_elan->vcc33);
 }
 
 static int i2c_hid_of_elan_probe(struct i2c_client *client)
···
 	if (IS_ERR(ihid_elan->vccio))
 		return PTR_ERR(ihid_elan->vccio);
 
-	ihid_elan->vcc33 = devm_regulator_get(&client->dev, "vcc33");
-	if (IS_ERR(ihid_elan->vcc33))
-		return PTR_ERR(ihid_elan->vcc33);
-
 	ihid_elan->chip_data = device_get_match_data(&client->dev);
+
+	if (ihid_elan->chip_data->main_supply_name) {
+		ihid_elan->vcc33 = devm_regulator_get(&client->dev,
+						      ihid_elan->chip_data->main_supply_name);
+		if (IS_ERR(ihid_elan->vcc33))
+			return PTR_ERR(ihid_elan->vcc33);
+	}
 
 	return i2c_hid_core_probe(client, &ihid_elan->ops,
 				  ihid_elan->chip_data->hid_descriptor_address, 0);
···
 
 static const struct elan_i2c_hid_chip_data elan_ekth6915_chip_data = {
 	.post_power_delay_ms = 1,
-	.post_gpio_reset_delay_ms = 300,
+	.post_gpio_reset_on_delay_ms = 300,
 	.hid_descriptor_address = 0x0001,
+	.main_supply_name = "vcc33",
+};
+
+static const struct elan_i2c_hid_chip_data ilitek_ili9882t_chip_data = {
+	.post_power_delay_ms = 1,
+	.post_gpio_reset_on_delay_ms = 200,
+	.post_gpio_reset_off_delay_ms = 65,
+	.hid_descriptor_address = 0x0001,
+	/*
+	 * this touchscreen is tightly integrated with the panel and assumes
+	 * that the relevant power rails (other than the IO rail) have already
+	 * been turned on by the panel driver because we're a panel follower.
+	 */
+	.main_supply_name = NULL,
 };
 
 static const struct of_device_id elan_i2c_hid_of_match[] = {
 	{ .compatible = "elan,ekth6915", .data = &elan_ekth6915_chip_data },
+	{ .compatible = "ilitek,ili9882t", .data = &ilitek_ili9882t_chip_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, elan_i2c_hid_of_match);

drivers/hid/wacom.h

···
 		struct input_dev *input;
 		bool registered;
 		struct wacom_battery battery;
+		ktime_t active_time;
 	} remotes[WACOM_MAX_REMOTES];
 };
 

drivers/hid/wacom_sys.c

···
 	spin_lock_init(&remote->remote_lock);
 
 	error = kfifo_alloc(&remote->remote_fifo,
-			5 * sizeof(struct wacom_remote_data),
+			5 * sizeof(struct wacom_remote_work_data),
 			GFP_KERNEL);
 	if (error) {
 		hid_err(wacom->hdev, "failed allocating remote_fifo\n");
···
 	return;
 }
 
+static void wacom_remote_destroy_battery(struct wacom *wacom, int index)
+{
+	struct wacom_remote *remote = wacom->remote;
+
+	if (remote->remotes[index].battery.battery) {
+		devres_release_group(&wacom->hdev->dev,
+				     &remote->remotes[index].battery.bat_desc);
+		remote->remotes[index].battery.battery = NULL;
+		remote->remotes[index].active_time = 0;
+	}
+}
+
 static void wacom_remote_destroy_one(struct wacom *wacom, unsigned int index)
 {
 	struct wacom_remote *remote = wacom->remote;
···
 			remote->remotes[i].registered = false;
 			spin_unlock_irqrestore(&remote->remote_lock, flags);
 
-			if (remote->remotes[i].battery.battery)
-				devres_release_group(&wacom->hdev->dev,
-						     &remote->remotes[i].battery.bat_desc);
+			wacom_remote_destroy_battery(wacom, i);
 
 			if (remote->remotes[i].group.name)
 				devres_release_group(&wacom->hdev->dev,
···
 
 			remote->remotes[i].serial = 0;
 			remote->remotes[i].group.name = NULL;
-			remote->remotes[i].battery.battery = NULL;
 			wacom->led.groups[i].select = WACOM_STATUS_UNKNOWN;
 		}
 	}
···
 	if (remote->remotes[index].battery.battery)
 		return 0;
 
+	if (!remote->remotes[index].active_time)
+		return 0;
+
 	if (wacom->led.groups[index].select == WACOM_STATUS_UNKNOWN)
 		return 0;
 
···
 {
 	struct wacom *wacom = container_of(work, struct wacom, remote_work);
 	struct wacom_remote *remote = wacom->remote;
-	struct wacom_remote_data data;
+	ktime_t kt = ktime_get();
+	struct wacom_remote_work_data remote_work_data;
 	unsigned long flags;
 	unsigned int count;
-	u32 serial;
+	u32 work_serial;
 	int i;
 
 	spin_lock_irqsave(&remote->remote_lock, flags);
 
-	count = kfifo_out(&remote->remote_fifo, &data, sizeof(data));
+	count = kfifo_out(&remote->remote_fifo, &remote_work_data,
+			  sizeof(remote_work_data));
 
-	if (count != sizeof(data)) {
+	if (count != sizeof(remote_work_data)) {
 		hid_err(wacom->hdev,
 			"workitem triggered without status available\n");
 		spin_unlock_irqrestore(&remote->remote_lock, flags);
···
 	spin_unlock_irqrestore(&remote->remote_lock, flags);
 
 	for (i = 0; i < WACOM_MAX_REMOTES; i++) {
-		serial = data.remote[i].serial;
-		if (data.remote[i].connected) {
+		work_serial = remote_work_data.remote[i].serial;
+		if (work_serial) {
 
-			if (remote->remotes[i].serial == serial) {
+			if (kt - remote->remotes[i].active_time > WACOM_REMOTE_BATTERY_TIMEOUT
+			    && remote->remotes[i].active_time != 0)
+				wacom_remote_destroy_battery(wacom, i);
+
+			if (remote->remotes[i].serial == work_serial) {
 				wacom_remote_attach_battery(wacom, i);
 				continue;
 			}
···
 			if (remote->remotes[i].serial)
 				wacom_remote_destroy_one(wacom, i);
 
-			wacom_remote_create_one(wacom, serial, i);
+			wacom_remote_create_one(wacom, work_serial, i);
 
 		} else if (remote->remotes[i].serial) {
 			wacom_remote_destroy_one(wacom, i);

drivers/hid/wacom_wac.c

···
 	if (index < 0 || !remote->remotes[index].registered)
 		goto out;
 
+	remote->remotes[i].active_time = ktime_get();
 	input = remote->remotes[index].input;
 
 	input_report_key(input, BTN_0, (data[9] & 0x01));
···
 	struct wacom *wacom = container_of(wacom_wac, struct wacom, wacom_wac);
 	unsigned char *data = wacom_wac->data;
 	struct wacom_remote *remote = wacom->remote;
-	struct wacom_remote_data remote_data;
+	struct wacom_remote_work_data remote_data;
 	unsigned long flags;
 	int i, ret;
 
 	if (data[0] != WACOM_REPORT_DEVICE_LIST)
 		return;
 
-	memset(&remote_data, 0, sizeof(struct wacom_remote_data));
+	memset(&remote_data, 0, sizeof(struct wacom_remote_work_data));
 
 	for (i = 0; i < WACOM_MAX_REMOTES; i++) {
 		int j = i * 6;
 		int serial = (data[j+6] << 16) + (data[j+5] << 8) + data[j+4];
-		bool connected = data[j+2];
 
 		remote_data.remote[i].serial = serial;
-		remote_data.remote[i].connected = connected;
 	}
 
 	spin_lock_irqsave(&remote->remote_lock, flags);

drivers/hid/wacom_wac.h

···
 #define WACOM_NAME_MAX		64
 #define WACOM_MAX_REMOTES	5
 #define WACOM_STATUS_UNKNOWN	255
+#define WACOM_REMOTE_BATTERY_TIMEOUT	21000000000ll
 
 /* packet length for individual models */
 #define WACOM_PKGLEN_BBFUN	 9
···
 	ktime_t time_delayed;
 };
 
-struct wacom_remote_data {
+struct wacom_remote_work_data {
 	struct {
 		u32 serial;
-		bool connected;
 	} remote[WACOM_MAX_REMOTES];
 };
 

include/linux/hid.h

···
  */
 #define MAX_USBHID_BOOT_QUIRKS 4
 
+/**
+ * DOC: HID quirks
+ * | @HID_QUIRK_NOTOUCH:
+ * | @HID_QUIRK_IGNORE: ignore this device
+ * | @HID_QUIRK_NOGET:
+ * | @HID_QUIRK_HIDDEV_FORCE:
+ * | @HID_QUIRK_BADPAD:
+ * | @HID_QUIRK_MULTI_INPUT:
+ * | @HID_QUIRK_HIDINPUT_FORCE:
+ * | @HID_QUIRK_ALWAYS_POLL:
+ * | @HID_QUIRK_INPUT_PER_APP:
+ * | @HID_QUIRK_X_INVERT:
+ * | @HID_QUIRK_Y_INVERT:
+ * | @HID_QUIRK_SKIP_OUTPUT_REPORTS:
+ * | @HID_QUIRK_SKIP_OUTPUT_REPORT_ID:
+ * | @HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP:
+ * | @HID_QUIRK_HAVE_SPECIAL_DRIVER:
+ * | @HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE:
+ * | @HID_QUIRK_FULLSPEED_INTERVAL:
+ * | @HID_QUIRK_NO_INIT_REPORTS:
+ * | @HID_QUIRK_NO_IGNORE:
+ * | @HID_QUIRK_NO_INPUT_SYNC:
+ */
 /* BIT(0) reserved for backward compatibility, was HID_QUIRK_INVERT */
 #define HID_QUIRK_NOTOUCH			BIT(1)
 #define HID_QUIRK_IGNORE			BIT(2)
···
 #define HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP	BIT(18)
 #define HID_QUIRK_HAVE_SPECIAL_DRIVER		BIT(19)
 #define HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE	BIT(20)
+#define HID_QUIRK_NOINVERT			BIT(21)
 #define HID_QUIRK_FULLSPEED_INTERVAL		BIT(28)
 #define HID_QUIRK_NO_INIT_REPORTS		BIT(29)
 #define HID_QUIRK_NO_IGNORE			BIT(30)
···
 	struct hid_report *report;
 	struct input_dev *input;
 	const char *name;
-	bool registered;
 	struct list_head reports;	/* the list of reports */
 	unsigned int application;	/* application usage for this input */
+	bool registered;
 };
 
 enum hid_type {

include/linux/string_choices.h

···
 {
 	return v ? "read" : "write";
 }
+#define str_write_read(v)		str_read_write(!(v))
 
 static inline const char *str_on_off(bool v)
 {