Re: [PATCH 03/43] docs: hid: convert to ReST

[Benjamin Tissoires]

On Fri, Jun 28, 2019 at 2:21 PM Mauro Carvalho Chehab
<mchehab+samsung@xxxxxxxxxx> wrote:
>
> Rename the HID documentation files to ReST, add an
> index for them and adjust in order to produce a nice html
> output via the Sphinx build system.
>
> While here, fix the sysfs example from hid-sensor.txt, that
> has a lot of "?" instead of the proper UTF-8 characters that
> are produced by the tree command.
>
> At its new index.rst, let's add a :orphan: while this is not linked to
> the main index.rst file, in order to avoid build warnings.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
> Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---

This patch has been pushed to for-5.3/doc in the HID tree.

Cheers,
Benjamin

>  .../hid/{hid-alps.txt => hid-alps.rst}        |  85 ++-
>  .../hid/{hid-sensor.txt => hid-sensor.rst}    | 192 +++----
>  .../{hid-transport.txt => hid-transport.rst}  |  82 ++-
>  Documentation/hid/{hiddev.txt => hiddev.rst}  | 154 ++++--
>  Documentation/hid/{hidraw.txt => hidraw.rst}  |  53 +-
>  Documentation/hid/index.rst                   |  18 +
>  Documentation/hid/intel-ish-hid.rst           | 485 ++++++++++++++++++
>  Documentation/hid/intel-ish-hid.txt           | 454 ----------------
>  Documentation/hid/{uhid.txt => uhid.rst}      |  46 +-
>  Documentation/input/input.rst                 |   2 +-
>  MAINTAINERS                                   |   2 +-
>  11 files changed, 897 insertions(+), 676 deletions(-)
>  rename Documentation/hid/{hid-alps.txt => hid-alps.rst} (64%)
>  rename Documentation/hid/{hid-sensor.txt => hid-sensor.rst} (61%)
>  rename Documentation/hid/{hid-transport.txt => hid-transport.rst} (93%)
>  rename Documentation/hid/{hiddev.txt => hiddev.rst} (77%)
>  rename Documentation/hid/{hidraw.txt => hidraw.rst} (89%)
>  create mode 100644 Documentation/hid/index.rst
>  create mode 100644 Documentation/hid/intel-ish-hid.rst
>  delete mode 100644 Documentation/hid/intel-ish-hid.txt
>  rename Documentation/hid/{uhid.txt => uhid.rst} (94%)
>
> diff --git a/Documentation/hid/hid-alps.txt b/Documentation/hid/hid-alps.rst
> similarity index 64%
> rename from Documentation/hid/hid-alps.txt
> rename to Documentation/hid/hid-alps.rst
> index 6b02a2447c77..e2f4c4c11e3f 100644
> --- a/Documentation/hid/hid-alps.txt
> +++ b/Documentation/hid/hid-alps.rst
> @@ -1,19 +1,26 @@
> +==========================
>  ALPS HID Touchpad Protocol
> -----------------------
> +==========================
>
>  Introduction
>  ------------
>  Currently ALPS HID driver supports U1 Touchpad device.
>
> -U1 devuce basic information.
> +U1 device basic information.
> +
> +==========     ======
>  Vender ID      0x044E
>  Product ID     0x120B
>  Version ID     0x0121
> +==========     ======
>
>
>  HID Descriptor
> -------------
> +--------------
> +
> +=======        ====================    =====   =======================================
>  Byte   Field                   Value   Notes
> +=======        ====================    =====   =======================================
>  0      wHIDDescLength          001E    Length of HID Descriptor : 30 bytes
>  2      bcdVersion              0100    Compliant with Version 1.00
>  4      wReportDescLength       00B2    Report Descriptor is 178 Bytes (0x00B2)
> @@ -28,32 +35,42 @@ Byte        Field                   Value   Notes
>  22     wProductID              120B    Product ID 0x120B
>  24     wVersionID              0121    Version 01.21
>  26     RESERVED                0000    RESERVED
> +=======        ====================    =====   =======================================
>
>
>  Report ID
> -------------
> -ReportID-1     (Input Reports) (HIDUsage-Mouse) for TP&SP
> -ReportID-2     (Input Reports) (HIDUsage-keyboard) for TP
> -ReportID-3     (Input Reports) (Vendor Usage: Max 10 finger data) for TP
> -ReportID-4     (Input Reports) (Vendor Usage: ON bit data) for GP
> -ReportID-5     (Feature Reports)       Feature Reports
> -ReportID-6     (Input Reports) (Vendor Usage: StickPointer data) for SP
> -ReportID-7     (Feature Reports)       Flash update (Bootloader)
> +---------
> +
> +==========     =================  =========================================
> +ReportID-1     (Input Reports)    (HIDUsage-Mouse) for TP&SP
> +ReportID-2     (Input Reports)    (HIDUsage-keyboard) for TP
> +ReportID-3     (Input Reports)    (Vendor Usage: Max 10 finger data) for TP
> +ReportID-4     (Input Reports)    (Vendor Usage: ON bit data) for GP
> +ReportID-5     (Feature Reports)  Feature Reports
> +ReportID-6     (Input Reports)    (Vendor Usage: StickPointer data) for SP
> +ReportID-7     (Feature Reports)  Flash update (Bootloader)
> +==========     =================  =========================================
>
>
>  Data pattern
>  ------------
> +
> +=====  ==========      =====   =================
>  Case1  ReportID_1      TP/SP   Relative/Relative
>  Case2  ReportID_3      TP      Absolute
>         ReportID_6      SP      Absolute
> +=====  ==========      =====   =================
>
>
>  Command Read/Write
>  ------------------
>  To read/write to RAM, need to send a commands to the device.
> +
>  The command format is as below.
>
>  DataByte(SET_REPORT)
> +
> +=====  ======================
>  Byte1  Command Byte
>  Byte2  Address - Byte 0 (LSB)
>  Byte3  Address - Byte 1
> @@ -61,13 +78,19 @@ Byte4       Address - Byte 2
>  Byte5  Address - Byte 3 (MSB)
>  Byte6  Value Byte
>  Byte7  Checksum
> +=====  ======================
>
>  Command Byte is read=0xD1/write=0xD2 .
> +
>  Address is read/write RAM address.
> +
>  Value Byte is writing data when you send the write commands.
> +
>  When you read RAM, there is no meaning.
>
>  DataByte(GET_REPORT)
> +
> +=====  ======================
>  Byte1  Response Byte
>  Byte2  Address - Byte 0 (LSB)
>  Byte3  Address - Byte 1
> @@ -75,6 +98,7 @@ Byte4 Address - Byte 2
>  Byte5  Address - Byte 3 (MSB)
>  Byte6  Value Byte
>  Byte7  Checksum
> +=====  ======================
>
>  Read value is stored in Value Byte.
>
> @@ -82,7 +106,11 @@ Read value is stored in Value Byte.
>  Packet Format
>  Touchpad data byte
>  ------------------
> -       b7      b6      b5      b4      b3      b2      b1      b0
> +
> +
> +======= ======= ======= ======= ======= ======= ======= ======= =====
> +-      b7      b6      b5      b4      b3      b2      b1      b0
> +======= ======= ======= ======= ======= ======= ======= ======= =====
>  1      0       0       SW6     SW5     SW4     SW3     SW2     SW1
>  2      0       0       0       Fcv     Fn3     Fn2     Fn1     Fn0
>  3      Xa0_7   Xa0_6   Xa0_5   Xa0_4   Xa0_3   Xa0_2   Xa0_1   Xa0_0
> @@ -114,17 +142,25 @@ Touchpad data byte
>  25     Ya4_7   Ya4_6   Ya4_5   Ya4_4   Ya4_3   Ya4_2   Ya4_1   Ya4_0
>  26     Ya4_15  Ya4_14  Ya4_13  Ya4_12  Ya4_11  Ya4_10  Ya4_9   Ya4_8
>  27     LFB4    Zs4_6   Zs4_5   Zs4_4   Zs4_3   Zs4_2   Zs4_1   Zs4_0
> +======= ======= ======= ======= ======= ======= ======= ======= =====
>
>
> -SW1-SW6:       SW ON/OFF status
> -Xan_15-0(16bit):X Absolute data of the "n"th finger
> -Yan_15-0(16bit):Y Absolute data of the "n"th finger
> -Zsn_6-0(7bit): Operation area of the "n"th finger
> +SW1-SW6:
> +       SW ON/OFF status
> +Xan_15-0(16bit):
> +       X Absolute data of the "n"th finger
> +Yan_15-0(16bit):
> +       Y Absolute data of the "n"th finger
> +Zsn_6-0(7bit):
> +       Operation area of the "n"th finger
>
>
>  StickPointer data byte
> -------------------
> -       b7      b6      b5      b4      b3      b2      b1      b0
> +----------------------
> +
> +======= ======= ======= ======= ======= ======= ======= ======= =====
> +-      b7      b6      b5      b4      b3      b2      b1      b0
> +======= ======= ======= ======= ======= ======= ======= ======= =====
>  Byte1  1       1       1       0       1       SW3     SW2     SW1
>  Byte2  X7      X6      X5      X4      X3      X2      X1      X0
>  Byte3  X15     X14     X13     X12     X11     X10     X9      X8
> @@ -132,8 +168,13 @@ Byte4      Y7      Y6      Y5      Y4      Y3      Y2      Y1      Y0
>  Byte5  Y15     Y14     Y13     Y12     Y11     Y10     Y9      Y8
>  Byte6  Z7      Z6      Z5      Z4      Z3      Z2      Z1      Z0
>  Byte7  T&P     Z14     Z13     Z12     Z11     Z10     Z9      Z8
> +======= ======= ======= ======= ======= ======= ======= ======= =====
>
> -SW1-SW3:       SW ON/OFF status
> -Xn_15-0(16bit):X Absolute data
> -Yn_15-0(16bit):Y Absolute data
> -Zn_14-0(15bit):Z
> +SW1-SW3:
> +       SW ON/OFF status
> +Xn_15-0(16bit):
> +       X Absolute data
> +Yn_15-0(16bit):
> +       Y Absolute data
> +Zn_14-0(15bit):
> +       Z
> diff --git a/Documentation/hid/hid-sensor.txt b/Documentation/hid/hid-sensor.rst
> similarity index 61%
> rename from Documentation/hid/hid-sensor.txt
> rename to Documentation/hid/hid-sensor.rst
> index b287752a31cd..758972e34971 100644
> --- a/Documentation/hid/hid-sensor.txt
> +++ b/Documentation/hid/hid-sensor.rst
> @@ -1,6 +1,6 @@
> -
> +=====================
>  HID Sensors Framework
> -======================
> +=====================
>  HID sensor framework provides necessary interfaces to implement sensor drivers,
>  which are connected to a sensor hub. The sensor hub is a HID device and it provides
>  a report descriptor conforming to HID 1.12 sensor usage tables.
> @@ -15,22 +15,22 @@ the drivers themselves."
>  This specification describes many usage IDs, which describe the type of sensor
>  and also the individual data fields. Each sensor can have variable number of
>  data fields. The length and order is specified in the report descriptor. For
> -example a part of report descriptor can look like:
> +example a part of report descriptor can look like::
>
> -   INPUT(1)[INPUT]
> - ..
> -    Field(2)
> -      Physical(0020.0073)
> -      Usage(1)
> -        0020.045f
> -      Logical Minimum(-32767)
> -      Logical Maximum(32767)
> -      Report Size(8)
> -      Report Count(1)
> -      Report Offset(16)
> -      Flags(Variable Absolute)
> -..
> -..
> +     INPUT(1)[INPUT]
> +   ..
> +      Field(2)
> +        Physical(0020.0073)
> +        Usage(1)
> +          0020.045f
> +        Logical Minimum(-32767)
> +        Logical Maximum(32767)
> +        Report Size(8)
> +        Report Count(1)
> +        Report Offset(16)
> +        Flags(Variable Absolute)
> +  ..
> +  ..
>
>  The report is indicating "sensor page (0x20)" contains an accelerometer-3D (0x73).
>  This accelerometer-3D has some fields. Here for example field 2 is motion intensity
> @@ -40,13 +40,14 @@ data will use this format.
>
>
>  Implementation
> -=================
> +==============
>
>  This specification defines many different types of sensors with different sets of
>  data fields. It is difficult to have a common input event to user space applications,
>  for different sensors. For example an accelerometer can send X,Y and Z data, whereas
>  an ambient light sensor can send illumination data.
>  So the implementation has two parts:
> +
>  - Core hid driver
>  - Individual sensor processing part (sensor drivers)
>
> @@ -55,8 +56,11 @@ Core driver
>  The core driver registers (hid-sensor-hub) registers as a HID driver. It parses
>  report descriptors and identifies all the sensors present. It adds an MFD device
>  with name HID-SENSOR-xxxx (where xxxx is usage id from the specification).
> -For example
> +
> +For example:
> +
>  HID-SENSOR-200073 is registered for an Accelerometer 3D driver.
> +
>  So if any driver with this name is inserted, then the probe routine for that
>  function will be called. So an accelerometer processing driver can register
>  with this name and will be probed if there is an accelerometer-3D detected.
> @@ -66,7 +70,8 @@ drivers to register and get events for that usage id. Also it provides parsing
>  functions, which get and set each input/feature/output report.
>
>  Individual sensor processing part (sensor drivers)
> ------------
> +--------------------------------------------------
> +
>  The processing driver will use an interface provided by the core driver to parse
>  the report and get the indexes of the fields and also can get events. This driver
>  can use IIO interface to use the standard ABI defined for a type of sensor.
> @@ -75,31 +80,34 @@ can use IIO interface to use the standard ABI defined for a type of sensor.
>  Core driver Interface
>  =====================
>
> -Callback structure:
> -Each processing driver can use this structure to set some callbacks.
> +Callback structure::
> +
> +  Each processing driver can use this structure to set some callbacks.
>         int (*suspend)(..): Callback when HID suspend is received
>         int (*resume)(..): Callback when HID resume is received
>         int (*capture_sample)(..): Capture a sample for one of its data fields
>         int (*send_event)(..): One complete event is received which can have
>                                 multiple data fields.
>
> -Registration functions:
> -int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
> +Registration functions::
> +
> +  int sensor_hub_register_callback(struct hid_sensor_hub_device *hsdev,
>                         u32 usage_id,
>                         struct hid_sensor_hub_callbacks *usage_callback):
>
>  Registers callbacks for an usage id. The callback functions are not allowed
> -to sleep.
> +to sleep::
>
>
> -int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
> +  int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
>                         u32 usage_id):
>
>  Removes callbacks for an usage id.
>
>
> -Parsing function:
> -int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
> +Parsing function::
> +
> +  int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
>                         u8 type,
>                         u32 usage_id, u32 attr_usage_id,
>                         struct hid_sensor_hub_attribute_info *info);
> @@ -110,26 +118,27 @@ so that fields can be set or get individually.
>  These indexes avoid searching every time and getting field index to get or set.
>
>
> -Set Feature report
> -int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
> +Set Feature report::
> +
> +  int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
>                         u32 field_index, s32 value);
>
>  This interface is used to set a value for a field in feature report. For example
>  if there is a field report_interval, which is parsed by a call to
> -sensor_hub_input_get_attribute_info before, then it can directly set that individual
> -field.
> +sensor_hub_input_get_attribute_info before, then it can directly set that
> +individual field::
>
>
> -int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
> +  int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
>                         u32 field_index, s32 *value);
>
>  This interface is used to get a value for a field in input report. For example
>  if there is a field report_interval, which is parsed by a call to
> -sensor_hub_input_get_attribute_info before, then it can directly get that individual
> -field value.
> +sensor_hub_input_get_attribute_info before, then it can directly get that
> +individual field value::
>
>
> -int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
> +  int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
>                         u32 usage_id,
>                         u32 attr_usage_id, u32 report_id);
>
> @@ -143,6 +152,8 @@ registered callback function to process the sample.
>  ----------
>
>  HID Custom and generic Sensors
> +------------------------------
> +
>
>  HID Sensor specification defines two special sensor usage types. Since they
>  don't represent a standard sensor, it is not possible to define using Linux IIO
> @@ -158,66 +169,73 @@ keyboard attached/detached or lid open/close.
>  To allow application to utilize these sensors, here they are exported uses sysfs
>  attribute groups, attributes and misc device interface.
>
> -An example of this representation on sysfs:
> -/sys/devices/pci0000:00/INT33C2:00/i2c-0/i2c-INT33D1:00/0018:8086:09FA.0001/HID-SENSOR-2000e1.6.auto$ tree -R
> -.
> -????????? enable_sensor
> -????????? feature-0-200316
> -??????? ????????? feature-0-200316-maximum
> -??????? ????????? feature-0-200316-minimum
> -??????? ????????? feature-0-200316-name
> -??????? ????????? feature-0-200316-size
> -??????? ????????? feature-0-200316-unit-expo
> -??????? ????????? feature-0-200316-units
> -??????? ????????? feature-0-200316-value
> -????????? feature-1-200201
> -??????? ????????? feature-1-200201-maximum
> -??????? ????????? feature-1-200201-minimum
> -??????? ????????? feature-1-200201-name
> -??????? ????????? feature-1-200201-size
> -??????? ????????? feature-1-200201-unit-expo
> -??????? ????????? feature-1-200201-units
> -??????? ????????? feature-1-200201-value
> -????????? input-0-200201
> -??????? ????????? input-0-200201-maximum
> -??????? ????????? input-0-200201-minimum
> -??????? ????????? input-0-200201-name
> -??????? ????????? input-0-200201-size
> -??????? ????????? input-0-200201-unit-expo
> -??????? ????????? input-0-200201-units
> -??????? ????????? input-0-200201-value
> -????????? input-1-200202
> -??????? ????????? input-1-200202-maximum
> -??????? ????????? input-1-200202-minimum
> -??????? ????????? input-1-200202-name
> -??????? ????????? input-1-200202-size
> -??????? ????????? input-1-200202-unit-expo
> -??????? ????????? input-1-200202-units
> -??????? ????????? input-1-200202-value
> +An example of this representation on sysfs::
> +
> +  /sys/devices/pci0000:00/INT33C2:00/i2c-0/i2c-INT33D1:00/0018:8086:09FA.0001/HID-SENSOR-2000e1.6.auto$ tree -R
> +  .
> +  â   âââ  enable_sensor
> +  â   â   âââ feature-0-200316
> +  â   â   â   âââ feature-0-200316-maximum
> +  â   â   â   âââ feature-0-200316-minimum
> +  â   â   â   âââ feature-0-200316-name
> +  â   â   â   âââ feature-0-200316-size
> +  â   â   â   âââ feature-0-200316-unit-expo
> +  â   â   â   âââ feature-0-200316-units
> +  â   â   â   âââ feature-0-200316-value
> +  â   â   âââ feature-1-200201
> +  â   â   â   âââ feature-1-200201-maximum
> +  â   â   â   âââ feature-1-200201-minimum
> +  â   â   â   âââ feature-1-200201-name
> +  â   â   â   âââ feature-1-200201-size
> +  â   â   â   âââ feature-1-200201-unit-expo
> +  â   â   â   âââ feature-1-200201-units
> +  â   â   â   âââ feature-1-200201-value
> +  â   â   âââ input-0-200201
> +  â   â   â   âââ input-0-200201-maximum
> +  â   â   â   âââ input-0-200201-minimum
> +  â   â   â   âââ input-0-200201-name
> +  â   â   â   âââ input-0-200201-size
> +  â   â   â   âââ input-0-200201-unit-expo
> +  â   â   â   âââ input-0-200201-units
> +  â   â   â   âââ input-0-200201-value
> +  â   â   âââ input-1-200202
> +  â   â   â   âââ input-1-200202-maximum
> +  â   â   â   âââ input-1-200202-minimum
> +  â   â   â   âââ input-1-200202-name
> +  â   â   â   âââ input-1-200202-size
> +  â   â   â   âââ input-1-200202-unit-expo
> +  â   â   â   âââ input-1-200202-units
> +  â   â   â   âââ input-1-200202-value
>
>  Here there is a custom sensors with four fields, two feature and two inputs.
>  Each field is represented by a set of attributes. All fields except the "value"
>  are read only. The value field is a RW field.
> -Example
> -/sys/bus/platform/devices/HID-SENSOR-2000e1.6.auto/feature-0-200316$ grep -r . *
> -feature-0-200316-maximum:6
> -feature-0-200316-minimum:0
> -feature-0-200316-name:property-reporting-state
> -feature-0-200316-size:1
> -feature-0-200316-unit-expo:0
> -feature-0-200316-units:25
> -feature-0-200316-value:1
> +
> +Example::
> +
> +  /sys/bus/platform/devices/HID-SENSOR-2000e1.6.auto/feature-0-200316$ grep -r . *
> +  feature-0-200316-maximum:6
> +  feature-0-200316-minimum:0
> +  feature-0-200316-name:property-reporting-state
> +  feature-0-200316-size:1
> +  feature-0-200316-unit-expo:0
> +  feature-0-200316-units:25
> +  feature-0-200316-value:1
>
>  How to enable such sensor?
> +^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
>  By default sensor can be power gated. To enable sysfs attribute "enable" can be
> -used.
> -$ echo 1 > enable_sensor
> +used::
> +
> +       $ echo 1 > enable_sensor
>
>  Once enabled and powered on, sensor can report value using HID reports.
> -These reports are pushed using misc device interface in a FIFO order.
> -/dev$ tree | grep HID-SENSOR-2000e1.6.auto
> -??????? ????????? 10:53 -> ../HID-SENSOR-2000e1.6.auto
> -????????? HID-SENSOR-2000e1.6.auto
> +These reports are pushed using misc device interface in a FIFO order::
> +
> +       /dev$ tree | grep HID-SENSOR-2000e1.6.auto
> +       â   â   â   âââ 10:53 -> ../HID-SENSOR-2000e1.6.auto
> +       â   âââ  HID-SENSOR-2000e1.6.auto
>
>  Each reports can be of variable length preceded by a header. This header
>  consist of a 32 bit usage id, 64 bit time stamp and 32 bit length field of raw
> diff --git a/Documentation/hid/hid-transport.txt b/Documentation/hid/hid-transport.rst
> similarity index 93%
> rename from Documentation/hid/hid-transport.txt
> rename to Documentation/hid/hid-transport.rst
> index 4f41d67f1b4b..0fe526f36db6 100644
> --- a/Documentation/hid/hid-transport.txt
> +++ b/Documentation/hid/hid-transport.rst
> @@ -1,5 +1,6 @@
> -                          HID I/O Transport Drivers
> -                         ===========================
> +=========================
> +HID I/O Transport Drivers
> +=========================
>
>  The HID subsystem is independent of the underlying transport driver. Initially,
>  only USB was supported, but other specifications adopted the HID design and
> @@ -16,6 +17,8 @@ transport and device setup/management. HID core is responsible of
>  report-parsing, report interpretation and the user-space API. Device specifics
>  and quirks are handled by all layers depending on the quirk.
>
> +::
> +
>   +-----------+  +-----------+            +-----------+  +-----------+
>   | Device #1 |  | Device #i |            | Device #j |  | Device #k |
>   +-----------+  +-----------+            +-----------+  +-----------+
> @@ -42,8 +45,9 @@ and quirks are handled by all layers depending on the quirk.
>   +----------------+  +-----------+  +------------------+  +------------------+
>
>  Example Drivers:
> -  I/O: USB, I2C, Bluetooth-l2cap
> -  Transport: USB-HID, I2C-HID, BT-HIDP
> +
> +  - I/O: USB, I2C, Bluetooth-l2cap
> +  - Transport: USB-HID, I2C-HID, BT-HIDP
>
>  Everything below "HID Core" is simplified in this graph as it is only of
>  interest to HID device drivers. Transport drivers do not need to know the
> @@ -183,7 +187,7 @@ Other ctrl-channel requests are supported by USB-HID but are not available
>  -------------------
>
>  Transport drivers normally use the following procedure to register a new device
> -with HID core:
> +with HID core::
>
>         struct hid_device *hid;
>         int ret;
> @@ -215,7 +219,7 @@ Once hid_add_device() is entered, HID core might use the callbacks provided in
>  "custom_ll_driver". Note that fields like "country" can be ignored by underlying
>  transport-drivers if not supported.
>
> -To unregister a device, use:
> +To unregister a device, use::
>
>         hid_destroy_device(hid);
>
> @@ -226,73 +230,110 @@ driver callbacks.
>  -----------------------------
>
>  The available HID callbacks are:
> - - int (*start) (struct hid_device *hdev)
> +
> +   ::
> +
> +      int (*start) (struct hid_device *hdev)
> +
>     Called from HID device drivers once they want to use the device. Transport
>     drivers can choose to setup their device in this callback. However, normally
>     devices are already set up before transport drivers register them to HID core
>     so this is mostly only used by USB-HID.
>
> - - void (*stop) (struct hid_device *hdev)
> +   ::
> +
> +      void (*stop) (struct hid_device *hdev)
> +
>     Called from HID device drivers once they are done with a device. Transport
>     drivers can free any buffers and deinitialize the device. But note that
>     ->start() might be called again if another HID device driver is loaded on the
>     device.
> +
>     Transport drivers are free to ignore it and deinitialize devices after they
>     destroyed them via hid_destroy_device().
>
> - - int (*open) (struct hid_device *hdev)
> +   ::
> +
> +      int (*open) (struct hid_device *hdev)
> +
>     Called from HID device drivers once they are interested in data reports.
>     Usually, while user-space didn't open any input API/etc., device drivers are
>     not interested in device data and transport drivers can put devices asleep.
>     However, once ->open() is called, transport drivers must be ready for I/O.
>     ->open() calls are nested for each client that opens the HID device.
>
> - - void (*close) (struct hid_device *hdev)
> +   ::
> +
> +      void (*close) (struct hid_device *hdev)
> +
>     Called from HID device drivers after ->open() was called but they are no
>     longer interested in device reports. (Usually if user-space closed any input
>     devices of the driver).
> +
>     Transport drivers can put devices asleep and terminate any I/O of all
>     ->open() calls have been followed by a ->close() call. However, ->start() may
>     be called again if the device driver is interested in input reports again.
>
> - - int (*parse) (struct hid_device *hdev)
> +   ::
> +
> +      int (*parse) (struct hid_device *hdev)
> +
>     Called once during device setup after ->start() has been called. Transport
>     drivers must read the HID report-descriptor from the device and tell HID core
>     about it via hid_parse_report().
>
> - - int (*power) (struct hid_device *hdev, int level)
> +   ::
> +
> +      int (*power) (struct hid_device *hdev, int level)
> +
>     Called by HID core to give PM hints to transport drivers. Usually this is
>     analogical to the ->open() and ->close() hints and redundant.
>
> - - void (*request) (struct hid_device *hdev, struct hid_report *report,
> -                    int reqtype)
> +   ::
> +
> +      void (*request) (struct hid_device *hdev, struct hid_report *report,
> +                      int reqtype)
> +
>     Send an HID request on the ctrl channel. "report" contains the report that
>     should be sent and "reqtype" the request type. Request-type can be
>     HID_REQ_SET_REPORT or HID_REQ_GET_REPORT.
> +
>     This callback is optional. If not provided, HID core will assemble a raw
>     report following the HID specs and send it via the ->raw_request() callback.
>     The transport driver is free to implement this asynchronously.
>
> - - int (*wait) (struct hid_device *hdev)
> +   ::
> +
> +      int (*wait) (struct hid_device *hdev)
> +
>     Used by HID core before calling ->request() again. A transport driver can use
>     it to wait for any pending requests to complete if only one request is
>     allowed at a time.
>
> - - int (*raw_request) (struct hid_device *hdev, unsigned char reportnum,
> -                       __u8 *buf, size_t count, unsigned char rtype,
> -                       int reqtype)
> +   ::
> +
> +      int (*raw_request) (struct hid_device *hdev, unsigned char reportnum,
> +                          __u8 *buf, size_t count, unsigned char rtype,
> +                          int reqtype)
> +
>     Same as ->request() but provides the report as raw buffer. This request shall
>     be synchronous. A transport driver must not use ->wait() to complete such
>     requests. This request is mandatory and hid core will reject the device if
>     it is missing.
>
> - - int (*output_report) (struct hid_device *hdev, __u8 *buf, size_t len)
> +   ::
> +
> +      int (*output_report) (struct hid_device *hdev, __u8 *buf, size_t len)
> +
>     Send raw output report via intr channel. Used by some HID device drivers
>     which require high throughput for outgoing requests on the intr channel. This
>     must not cause SET_REPORT calls! This must be implemented as asynchronous
>     output report on the intr channel!
>
> - - int (*idle) (struct hid_device *hdev, int report, int idle, int reqtype)
> +   ::
> +
> +      int (*idle) (struct hid_device *hdev, int report, int idle, int reqtype)
> +
>     Perform SET/GET_IDLE request. Only used by USB-HID, do not implement!
>
>  2.3) Data Path
> @@ -314,4 +355,5 @@ transport driver and not passed to hid_input_report().
>  Acknowledgements to SET_REPORT requests are not of interest to HID core.
>
>  ----------------------------------------------------
> +
>  Written 2013, David Herrmann <dh.herrmann@xxxxxxxxx>
> diff --git a/Documentation/hid/hiddev.txt b/Documentation/hid/hiddev.rst
> similarity index 77%
> rename from Documentation/hid/hiddev.txt
> rename to Documentation/hid/hiddev.rst
> index 638448707aa2..209e6ba4e019 100644
> --- a/Documentation/hid/hiddev.txt
> +++ b/Documentation/hid/hiddev.rst
> @@ -1,6 +1,9 @@
> +================================================
>  Care and feeding of your Human Interface Devices
> +================================================
>
> -INTRODUCTION
> +Introduction
> +============
>
>  In addition to the normal input type HID devices, USB also uses the
>  human interface device protocols for things that are not really human
> @@ -16,38 +19,40 @@ normalised event interface - see Documentation/input/input.rst
>  * the hiddev interface, which provides fairly raw HID events
>
>  The data flow for a HID event produced by a device is something like
> -the following :
> +the following::
>
>   usb.c ---> hid-core.c  ----> hid-input.c ----> [keyboard/mouse/joystick/event]
>                           |
>                           |
> -                          --> hiddev.c ----> POWER / MONITOR CONTROL
> +                          --> hiddev.c ----> POWER / MONITOR CONTROL
>
>  In addition, other subsystems (apart from USB) can potentially feed
>  events into the input subsystem, but these have no effect on the hid
>  device interface.
>
> -USING THE HID DEVICE INTERFACE
> +Using the HID Device Interface
> +==============================
>
>  The hiddev interface is a char interface using the normal USB major,
>  with the minor numbers starting at 96 and finishing at 111. Therefore,
> -you need the following commands:
> -mknod /dev/usb/hiddev0 c 180 96
> -mknod /dev/usb/hiddev1 c 180 97
> -mknod /dev/usb/hiddev2 c 180 98
> -mknod /dev/usb/hiddev3 c 180 99
> -mknod /dev/usb/hiddev4 c 180 100
> -mknod /dev/usb/hiddev5 c 180 101
> -mknod /dev/usb/hiddev6 c 180 102
> -mknod /dev/usb/hiddev7 c 180 103
> -mknod /dev/usb/hiddev8 c 180 104
> -mknod /dev/usb/hiddev9 c 180 105
> -mknod /dev/usb/hiddev10 c 180 106
> -mknod /dev/usb/hiddev11 c 180 107
> -mknod /dev/usb/hiddev12 c 180 108
> -mknod /dev/usb/hiddev13 c 180 109
> -mknod /dev/usb/hiddev14 c 180 110
> -mknod /dev/usb/hiddev15 c 180 111
> +you need the following commands::
> +
> +       mknod /dev/usb/hiddev0 c 180 96
> +       mknod /dev/usb/hiddev1 c 180 97
> +       mknod /dev/usb/hiddev2 c 180 98
> +       mknod /dev/usb/hiddev3 c 180 99
> +       mknod /dev/usb/hiddev4 c 180 100
> +       mknod /dev/usb/hiddev5 c 180 101
> +       mknod /dev/usb/hiddev6 c 180 102
> +       mknod /dev/usb/hiddev7 c 180 103
> +       mknod /dev/usb/hiddev8 c 180 104
> +       mknod /dev/usb/hiddev9 c 180 105
> +       mknod /dev/usb/hiddev10 c 180 106
> +       mknod /dev/usb/hiddev11 c 180 107
> +       mknod /dev/usb/hiddev12 c 180 108
> +       mknod /dev/usb/hiddev13 c 180 109
> +       mknod /dev/usb/hiddev14 c 180 110
> +       mknod /dev/usb/hiddev15 c 180 111
>
>  So you point your hiddev compliant user-space program at the correct
>  interface for your device, and it all just works.
> @@ -56,7 +61,9 @@ Assuming that you have a hiddev compliant user-space program, of
>  course. If you need to write one, read on.
>
>
> -THE HIDDEV API
> +The HIDDEV API
> +==============
> +
>  This description should be read in conjunction with the HID
>  specification, freely available from http://www.usb.org, and
>  conveniently linked of http://www.linux-usb.org.
> @@ -69,12 +76,14 @@ each of which can have one or more "usages".  In the hid-core,
>  each one of these usages has a single signed 32 bit value.
>
>  read():
> +-------
> +
>  This is the event interface.  When the HID device's state changes,
>  it performs an interrupt transfer containing a report which contains
>  the changed value.  The hid-core.c module parses the report, and
>  returns to hiddev.c the individual usages that have changed within
>  the report.  In its basic mode, the hiddev will make these individual
> -usage changes available to the reader using a struct hiddev_event:
> +usage changes available to the reader using a struct hiddev_event::
>
>         struct hiddev_event {
>             unsigned hid;
> @@ -90,13 +99,19 @@ behavior of the read() function can be modified using the HIDIOCSFLAG
>  ioctl() described below.
>
>
> -ioctl():
> -This is the control interface. There are a number of controls:
> +ioctl():
> +--------
>
> -HIDIOCGVERSION - int (read)
> -Gets the version code out of the hiddev driver.
> +This is the control interface. There are a number of controls:
> +
> +HIDIOCGVERSION
> +  - int (read)
> +
> + Gets the version code out of the hiddev driver.
> +
> +HIDIOCAPPLICATION
> +  - (none)
>
> -HIDIOCAPPLICATION - (none)
>  This ioctl call returns the HID application usage associated with the
>  hid device. The third argument to ioctl() specifies which application
>  index to get. This is useful when the device has more than one
> @@ -104,25 +119,33 @@ application collection. If the index is invalid (greater or equal to
>  the number of application collections this device has) the ioctl
>  returns -1. You can find out beforehand how many application
>  collections the device has from the num_applications field from the
> -hiddev_devinfo structure.
> +hiddev_devinfo structure.
> +
> +HIDIOCGCOLLECTIONINFO
> +  - struct hiddev_collection_info (read/write)
>
> -HIDIOCGCOLLECTIONINFO - struct hiddev_collection_info (read/write)
>  This returns a superset of the information above, providing not only
>  application collections, but all the collections the device has.  It
>  also returns the level the collection lives in the hierarchy.
> -The user passes in a hiddev_collection_info struct with the index
> -field set to the index that should be returned.  The ioctl fills in
> -the other fields.  If the index is larger than the last collection
> +The user passes in a hiddev_collection_info struct with the index
> +field set to the index that should be returned.  The ioctl fills in
> +the other fields.  If the index is larger than the last collection
>  index, the ioctl returns -1 and sets errno to -EINVAL.
>
> -HIDIOCGDEVINFO - struct hiddev_devinfo (read)
> +HIDIOCGDEVINFO
> +  - struct hiddev_devinfo (read)
> +
>  Gets a hiddev_devinfo structure which describes the device.
>
> -HIDIOCGSTRING - struct hiddev_string_descriptor (read/write)
> +HIDIOCGSTRING
> +  - struct hiddev_string_descriptor (read/write)
> +
>  Gets a string descriptor from the device. The caller must fill in the
>  "index" field to indicate which descriptor should be returned.
>
> -HIDIOCINITREPORT - (none)
> +HIDIOCINITREPORT
> +  - (none)
> +
>  Instructs the kernel to retrieve all input and feature report values
>  from the device. At this point, all the usage structures will contain
>  current values for the device, and will maintain it as the device
> @@ -130,21 +153,29 @@ changes.  Note that the use of this ioctl is unnecessary in general,
>  since later kernels automatically initialize the reports from the
>  device at attach time.
>
> -HIDIOCGNAME - string (variable length)
> +HIDIOCGNAME
> +  - string (variable length)
> +
>  Gets the device name
>
> -HIDIOCGREPORT - struct hiddev_report_info (write)
> +HIDIOCGREPORT
> +  - struct hiddev_report_info (write)
> +
>  Instructs the kernel to get a feature or input report from the device,
>  in order to selectively update the usage structures (in contrast to
>  INITREPORT).
>
> -HIDIOCSREPORT - struct hiddev_report_info (write)
> +HIDIOCSREPORT
> +  - struct hiddev_report_info (write)
> +
>  Instructs the kernel to send a report to the device. This report can
>  be filled in by the user through HIDIOCSUSAGE calls (below) to fill in
>  individual usage values in the report before sending the report in full
> -to the device.
> +to the device.
> +
> +HIDIOCGREPORTINFO
> +  - struct hiddev_report_info (read/write)
>
> -HIDIOCGREPORTINFO - struct hiddev_report_info (read/write)
>  Fills in a hiddev_report_info structure for the user. The report is
>  looked up by type (input, output or feature) and id, so these fields
>  must be filled in by the user. The ID can be absolute -- the actual
> @@ -154,52 +185,67 @@ report_id) for the next report after report_id. Without a-priori
>  information about report ids, the right way to use this ioctl is to
>  use the relative IDs above to enumerate the valid IDs. The ioctl
>  returns non-zero when there is no more next ID. The real report ID is
> -filled into the returned hiddev_report_info structure.
> +filled into the returned hiddev_report_info structure.
> +
> +HIDIOCGFIELDINFO
> +  - struct hiddev_field_info (read/write)
>
> -HIDIOCGFIELDINFO - struct hiddev_field_info (read/write)
>  Returns the field information associated with a report in a
>  hiddev_field_info structure. The user must fill in report_id and
>  report_type in this structure, as above. The field_index should also
>  be filled in, which should be a number from 0 and maxfield-1, as
> -returned from a previous HIDIOCGREPORTINFO call.
> +returned from a previous HIDIOCGREPORTINFO call.
> +
> +HIDIOCGUCODE
> +  - struct hiddev_usage_ref (read/write)
>
> -HIDIOCGUCODE - struct hiddev_usage_ref (read/write)
>  Returns the usage_code in a hiddev_usage_ref structure, given that
>  given its report type, report id, field index, and index within the
>  field have already been filled into the structure.
>
> -HIDIOCGUSAGE - struct hiddev_usage_ref (read/write)
> +HIDIOCGUSAGE
> +  - struct hiddev_usage_ref (read/write)
> +
>  Returns the value of a usage in a hiddev_usage_ref structure. The
>  usage to be retrieved can be specified as above, or the user can
>  choose to fill in the report_type field and specify the report_id as
>  HID_REPORT_ID_UNKNOWN. In this case, the hiddev_usage_ref will be
>  filled in with the report and field information associated with this
> -usage if it is found.
> +usage if it is found.
> +
> +HIDIOCSUSAGE
> +  - struct hiddev_usage_ref (write)
>
> -HIDIOCSUSAGE - struct hiddev_usage_ref (write)
>  Sets the value of a usage in an output report.  The user fills in
>  the hiddev_usage_ref structure as above, but additionally fills in
>  the value field.
>
> -HIDIOGCOLLECTIONINDEX - struct hiddev_usage_ref (write)
> +HIDIOGCOLLECTIONINDEX
> +  - struct hiddev_usage_ref (write)
> +
>  Returns the collection index associated with this usage.  This
>  indicates where in the collection hierarchy this usage sits.
>
> -HIDIOCGFLAG - int (read)
> -HIDIOCSFLAG - int (write)
> +HIDIOCGFLAG
> +  - int (read)
> +HIDIOCSFLAG
> +  - int (write)
> +
>  These operations respectively inspect and replace the mode flags
>  that influence the read() call above.  The flags are as follows:
>
> -    HIDDEV_FLAG_UREF - read() calls will now return
> +    HIDDEV_FLAG_UREF
> +      - read() calls will now return
>          struct hiddev_usage_ref instead of struct hiddev_event.
>          This is a larger structure, but in situations where the
>          device has more than one usage in its reports with the
>          same usage code, this mode serves to resolve such
>          ambiguity.
>
> -    HIDDEV_FLAG_REPORT - This flag can only be used in conjunction
> +    HIDDEV_FLAG_REPORT
> +      - This flag can only be used in conjunction
>          with HIDDEV_FLAG_UREF.  With this flag set, when the device
>          sends a report, a struct hiddev_usage_ref will be returned
> -        to read() filled in with the report_type and report_id, but
> +        to read() filled in with the report_type and report_id, but
>          with field_index set to FIELD_INDEX_NONE.  This serves as
>          additional notification when the device has sent a report.
> diff --git a/Documentation/hid/hidraw.txt b/Documentation/hid/hidraw.rst
> similarity index 89%
> rename from Documentation/hid/hidraw.txt
> rename to Documentation/hid/hidraw.rst
> index c8436e354f44..4a4a0ba1f362 100644
> --- a/Documentation/hid/hidraw.txt
> +++ b/Documentation/hid/hidraw.rst
> @@ -1,5 +1,6 @@
> -      HIDRAW - Raw Access to USB and Bluetooth Human Interface Devices
> -     ==================================================================
> +================================================================
> +HIDRAW - Raw Access to USB and Bluetooth Human Interface Devices
> +================================================================
>
>  The hidraw driver provides a raw interface to USB and Bluetooth Human
>  Interface Devices (HIDs).  It differs from hiddev in that reports sent and
> @@ -31,6 +32,7 @@ directly under /dev (eg: /dev/hidraw0).  As this location is distribution-
>  and udev rule-dependent, applications should use libudev to locate hidraw
>  devices attached to the system.  There is a tutorial on libudev with a
>  working example at:
> +
>         http://www.signal11.us/oss/udev/
>
>  The HIDRAW API
> @@ -51,7 +53,7 @@ byte.  For devices which do not use numbered reports, the report data
>  will begin at the first byte.
>
>  write()
> ---------
> +-------
>  The write() function will write a report to the device. For USB devices, if
>  the device has an INTERRUPT OUT endpoint, the report will be sent on that
>  endpoint. If it does not, the report will be sent over the control endpoint,
> @@ -62,38 +64,52 @@ number.  If the device does not use numbered reports, the first byte should
>  be set to 0. The report data itself should begin at the second byte.
>
>  ioctl()
> ---------
> +-------
>  Hidraw supports the following ioctls:
>
> -HIDIOCGRDESCSIZE: Get Report Descriptor Size
> +HIDIOCGRDESCSIZE:
> +       Get Report Descriptor Size
> +
>  This ioctl will get the size of the device's report descriptor.
>
> -HIDIOCGRDESC: Get Report Descriptor
> +HIDIOCGRDESC:
> +       Get Report Descriptor
> +
>  This ioctl returns the device's report descriptor using a
>  hidraw_report_descriptor struct.  Make sure to set the size field of the
>  hidraw_report_descriptor struct to the size returned from HIDIOCGRDESCSIZE.
>
> -HIDIOCGRAWINFO: Get Raw Info
> +HIDIOCGRAWINFO:
> +       Get Raw Info
> +
>  This ioctl will return a hidraw_devinfo struct containing the bus type, the
>  vendor ID (VID), and product ID (PID) of the device. The bus type can be one
> -of:
> -       BUS_USB
> -       BUS_HIL
> -       BUS_BLUETOOTH
> -       BUS_VIRTUAL
> +of::
> +
> +       - BUS_USB
> +       - BUS_HIL
> +       - BUS_BLUETOOTH
> +       - BUS_VIRTUAL
> +
>  which are defined in uapi/linux/input.h.
>
> -HIDIOCGRAWNAME(len): Get Raw Name
> +HIDIOCGRAWNAME(len):
> +       Get Raw Name
> +
>  This ioctl returns a string containing the vendor and product strings of
>  the device.  The returned string is Unicode, UTF-8 encoded.
>
> -HIDIOCGRAWPHYS(len): Get Physical Address
> +HIDIOCGRAWPHYS(len):
> +       Get Physical Address
> +
>  This ioctl returns a string representing the physical address of the device.
>  For USB devices, the string contains the physical path to the device (the
>  USB controller, hubs, ports, etc).  For Bluetooth devices, the string
>  contains the hardware (MAC) address of the device.
>
> -HIDIOCSFEATURE(len): Send a Feature Report
> +HIDIOCSFEATURE(len):
> +       Send a Feature Report
> +
>  This ioctl will send a feature report to the device.  Per the HID
>  specification, feature reports are always sent using the control endpoint.
>  Set the first byte of the supplied buffer to the report number.  For devices
> @@ -101,7 +117,9 @@ which do not use numbered reports, set the first byte to 0. The report data
>  begins in the second byte. Make sure to set len accordingly, to one more
>  than the length of the report (to account for the report number).
>
> -HIDIOCGFEATURE(len): Get a Feature Report
> +HIDIOCGFEATURE(len):
> +       Get a Feature Report
> +
>  This ioctl will request a feature report from the device using the control
>  endpoint.  The first byte of the supplied buffer should be set to the report
>  number of the requested report.  For devices which do not use numbered
> @@ -109,11 +127,12 @@ reports, set the first byte to 0.  The report will be returned starting at
>  the first byte of the buffer (ie: the report number is not returned).
>
>  Example
> ----------
> +-------
>  In samples/, find hid-example.c, which shows examples of read(), write(),
>  and all the ioctls for hidraw.  The code may be used by anyone for any
>  purpose, and can serve as a starting point for developing applications using
>  hidraw.
>
>  Document by:
> +
>         Alan Ott <alan@xxxxxxxxxxx>, Signal 11 Software
> diff --git a/Documentation/hid/index.rst b/Documentation/hid/index.rst
> new file mode 100644
> index 000000000000..af4324902622
> --- /dev/null
> +++ b/Documentation/hid/index.rst
> @@ -0,0 +1,18 @@
> +:orphan:
> +
> +=============================
> +Human Interface Devices (HID)
> +=============================
> +
> +.. toctree::
> +   :maxdepth: 1
> +
> +   hiddev
> +   hidraw
> +   hid-sensor
> +   hid-transport
> +
> +   uhid
> +
> +   hid-alps
> +   intel-ish-hid
> diff --git a/Documentation/hid/intel-ish-hid.rst b/Documentation/hid/intel-ish-hid.rst
> new file mode 100644
> index 000000000000..cccbf4be17d7
> --- /dev/null
> +++ b/Documentation/hid/intel-ish-hid.rst
> @@ -0,0 +1,485 @@
> +=================================
> +Intel Integrated Sensor Hub (ISH)
> +=================================
> +
> +A sensor hub enables the ability to offload sensor polling and algorithm
> +processing to a dedicated low power co-processor. This allows the core
> +processor to go into low power modes more often, resulting in the increased
> +battery life.
> +
> +There are many vendors providing external sensor hubs confirming to HID
> +Sensor usage tables, and used in several tablets, 2 in 1 convertible laptops
> +and embedded products. Linux had this support since Linux 3.9.
> +
> +Intel introduced integrated sensor hubs as a part of the SoC starting from
> +Cherry Trail and now supported on multiple generations of CPU packages. There
> +are many commercial devices already shipped with Integrated Sensor Hubs (ISH).
> +These ISH also comply to HID sensor specification, but the  difference is the
> +transport protocol used for communication. The current external sensor hubs
> +mainly use HID over i2C or USB. But ISH doesn't use either i2c or USB.
> +
> +1. Overview
> +===========
> +
> +Using a analogy with a usbhid implementation, the ISH follows a similar model
> +for a very high speed communication::
> +
> +       -----------------               ----------------------
> +       |    USB HID    |       -->     |    ISH HID         |
> +       -----------------               ----------------------
> +       -----------------               ----------------------
> +       |  USB protocol |       -->     |    ISH Transport   |
> +       -----------------               ----------------------
> +       -----------------               ----------------------
> +       |  EHCI/XHCI    |       -->     |    ISH IPC         |
> +       -----------------               ----------------------
> +             PCI                                PCI
> +       -----------------               ----------------------
> +        |Host controller|      -->     |    ISH processor   |
> +       -----------------               ----------------------
> +            USB Link
> +       -----------------               ----------------------
> +       | USB End points|       -->     |    ISH Clients     |
> +       -----------------               ----------------------
> +
> +Like USB protocol provides a method for device enumeration, link management
> +and user data encapsulation, the ISH also provides similar services. But it is
> +very light weight tailored to manage and communicate with ISH client
> +applications implemented in the firmware.
> +
> +The ISH allows multiple sensor management applications executing in the
> +firmware. Like USB endpoints the messaging can be to/from a client. As part of
> +enumeration process, these clients are identified. These clients can be simple
> +HID sensor applications, sensor calibration application or senor firmware
> +update application.
> +
> +The implementation model is similar, like USB bus, ISH transport is also
> +implemented as a bus. Each client application executing in the ISH processor
> +is registered as a device on this bus. The driver, which binds each device
> +(ISH HID driver) identifies the device type and registers with the hid core.
> +
> +2. ISH Implementation: Block Diagram
> +====================================
> +
> +::
> +
> +        ---------------------------
> +       |  User Space Applications  |
> +        ---------------------------
> +
> +  ----------------IIO ABI----------------
> +        --------------------------
> +       |  IIO Sensor Drivers     |
> +        --------------------------
> +        --------------------------
> +       |        IIO core         |
> +        --------------------------
> +        --------------------------
> +       |   HID Sensor Hub MFD    |
> +        --------------------------
> +        --------------------------
> +       |       HID Core          |
> +        --------------------------
> +        --------------------------
> +       |   HID over ISH Client   |
> +        --------------------------
> +        --------------------------
> +       |   ISH Transport (ISHTP) |
> +        --------------------------
> +        --------------------------
> +       |      IPC Drivers        |
> +        --------------------------
> +  OS
> +  ---------------- PCI -----------------
> +  Hardware + Firmware
> +        ----------------------------
> +       | ISH Hardware/Firmware(FW) |
> +        ----------------------------
> +
> +3. High level processing in above blocks
> +========================================
> +
> +3.1 Hardware Interface
> +----------------------
> +
> +The ISH is exposed as "Non-VGA unclassified PCI device" to the host. The PCI
> +product and vendor IDs are changed from different generations of processors. So
> +the source code which enumerate drivers needs to update from generation to
> +generation.
> +
> +3.2 Inter Processor Communication (IPC) driver
> +----------------------------------------------
> +
> +Location: drivers/hid/intel-ish-hid/ipc
> +
> +The IPC message used memory mapped I/O. The registers are defined in
> +hw-ish-regs.h.
> +
> +3.2.1 IPC/FW message types
> +^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +There are two types of messages, one for management of link and other messages
> +are to and from transport layers.
> +
> +TX and RX of Transport messages
> +...............................
> +
> +A set of memory mapped register offers support of multi byte messages TX and
> +RX (E.g.IPC_REG_ISH2HOST_MSG, IPC_REG_HOST2ISH_MSG). The IPC layer maintains
> +internal queues to sequence messages and send them in order to the FW.
> +Optionally the caller can register handler to get notification of completion.
> +A door bell mechanism is used in messaging to trigger processing in host and
> +client firmware side. When ISH interrupt handler is called, the ISH2HOST
> +doorbell register is used by host drivers to determine that the interrupt
> +is for ISH.
> +
> +Each side has 32 32-bit message registers and a 32-bit doorbell. Doorbell
> +register has the following format:
> +Bits 0..6: fragment length (7 bits are used)
> +Bits 10..13: encapsulated protocol
> +Bits 16..19: management command (for IPC management protocol)
> +Bit 31: doorbell trigger (signal H/W interrupt to the other side)
> +Other bits are reserved, should be 0.
> +
> +3.2.2 Transport layer interface
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +To abstract HW level IPC communication, a set of callbacks are registered.
> +The transport layer uses them to send and receive messages.
> +Refer to  struct ishtp_hw_ops for callbacks.
> +
> +3.3 ISH Transport layer
> +-----------------------
> +
> +Location: drivers/hid/intel-ish-hid/ishtp/
> +
> +3.3.1 A Generic Transport Layer
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +The transport layer is a bi-directional protocol, which defines:
> +- Set of commands to start, stop, connect, disconnect and flow control
> +(ishtp/hbm.h) for details
> +- A flow control mechanism to avoid buffer overflows
> +
> +This protocol resembles bus messages described in the following document:
> +http://www.intel.com/content/dam/www/public/us/en/documents/technical-\
> +specifications/dcmi-hi-1-0-spec.pdf "Chapter 7: Bus Message Layer"
> +
> +3.3.2 Connection and Flow Control Mechanism
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Each FW client and a protocol is identified by an UUID. In order to communicate
> +to a FW client, a connection must be established using connect request and
> +response bus messages. If successful, a pair (host_client_id and fw_client_id)
> +will identify the connection.
> +
> +Once connection is established, peers send each other flow control bus messages
> +independently. Every peer may send a message only if it has received a
> +flow-control credit before. Once it sent a message, it may not send another one
> +before receiving the next flow control credit.
> +Either side can send disconnect request bus message to end communication. Also
> +the link will be dropped if major FW reset occurs.
> +
> +3.3.3 Peer to Peer data transfer
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Peer to Peer data transfer can happen with or without using DMA. Depending on
> +the sensor bandwidth requirement DMA can be enabled by using module parameter
> +ishtp_use_dma under intel_ishtp.
> +
> +Each side (host and FW) manages its DMA transfer memory independently. When an
> +ISHTP client from either host or FW side wants to send something, it decides
> +whether to send over IPC or over DMA; for each transfer the decision is
> +independent. The sending side sends DMA_XFER message when the message is in
> +the respective host buffer (TX when host client sends, RX when FW client
> +sends). The recipient of DMA message responds with DMA_XFER_ACK, indicating
> +the sender that the memory region for that message may be reused.
> +
> +DMA initialization is started with host sending DMA_ALLOC_NOTIFY bus message
> +(that includes RX buffer) and FW responds with DMA_ALLOC_NOTIFY_ACK.
> +Additionally to DMA address communication, this sequence checks capabilities:
> +if thw host doesn't support DMA, then it won't send DMA allocation, so FW can't
> +send DMA; if FW doesn't support DMA then it won't respond with
> +DMA_ALLOC_NOTIFY_ACK, in which case host will not use DMA transfers.
> +Here ISH acts as busmaster DMA controller. Hence when host sends DMA_XFER,
> +it's request to do host->ISH DMA transfer; when FW sends DMA_XFER, it means
> +that it already did DMA and the message resides at host. Thus, DMA_XFER
> +and DMA_XFER_ACK act as ownership indicators.
> +
> +At initial state all outgoing memory belongs to the sender (TX to host, RX to
> +FW), DMA_XFER transfers ownership on the region that contains ISHTP message to
> +the receiving side, DMA_XFER_ACK returns ownership to the sender. A sender
> +needs not wait for previous DMA_XFER to be ack'ed, and may send another message
> +as long as remaining continuous memory in its ownership is enough.
> +In principle, multiple DMA_XFER and DMA_XFER_ACK messages may be sent at once
> +(up to IPC MTU), thus allowing for interrupt throttling.
> +Currently, ISH FW decides to send over DMA if ISHTP message is more than 3 IPC
> +fragments and via IPC otherwise.
> +
> +3.3.4 Ring Buffers
> +^^^^^^^^^^^^^^^^^^
> +
> +When a client initiate a connection, a ring or RX and TX buffers are allocated.
> +The size of ring can be specified by the client. HID client set 16 and 32 for
> +TX and RX buffers respectively. On send request from client, the data to be
> +sent is copied to one of the send ring buffer and scheduled to be sent using
> +bus message protocol. These buffers are required because the FW may have not
> +have processed the last message and may not have enough flow control credits
> +to send. Same thing holds true on receive side and flow control is required.
> +
> +3.3.5 Host Enumeration
> +^^^^^^^^^^^^^^^^^^^^^^
> +
> +The host enumeration bus command allow discovery of clients present in the FW.
> +There can be multiple sensor clients and clients for calibration function.
> +
> +To ease in implantation and allow independent driver handle each client
> +this transport layer takes advantage of Linux Bus driver model. Each
> +client is registered as device on the the transport bus (ishtp bus).
> +
> +Enumeration sequence of messages:
> +
> +- Host sends HOST_START_REQ_CMD, indicating that host ISHTP layer is up.
> +- FW responds with HOST_START_RES_CMD
> +- Host sends HOST_ENUM_REQ_CMD (enumerate FW clients)
> +- FW responds with HOST_ENUM_RES_CMD that includes bitmap of available FW
> +  client IDs
> +- For each FW ID found in that bitmap host sends
> +  HOST_CLIENT_PROPERTIES_REQ_CMD
> +- FW responds with HOST_CLIENT_PROPERTIES_RES_CMD. Properties include UUID,
> +  max ISHTP message size, etc.
> +- Once host received properties for that last discovered client, it considers
> +  ISHTP device fully functional (and allocates DMA buffers)
> +
> +3.4 HID over ISH Client
> +-----------------------
> +
> +Location: drivers/hid/intel-ish-hid
> +
> +The ISHTP client driver is responsible for:
> +
> +- enumerate HID devices under FW ISH client
> +- Get Report descriptor
> +- Register with HID core as a LL driver
> +- Process Get/Set feature request
> +- Get input reports
> +
> +3.5 HID Sensor Hub MFD and IIO sensor drivers
> +---------------------------------------------
> +
> +The functionality in these drivers is the same as an external sensor hub.
> +Refer to
> +Documentation/hid/hid-sensor.rst for HID sensor
> +Documentation/ABI/testing/sysfs-bus-iio for IIO ABIs to user space
> +
> +3.6 End to End HID transport Sequence Diagram
> +---------------------------------------------
> +
> +::
> +
> +  HID-ISH-CLN                    ISHTP                    IPC                             HW
> +          |                        |                       |                               |
> +          |                        |                       |-----WAKE UP------------------>|
> +          |                        |                       |                               |
> +          |                        |                       |-----HOST READY--------------->|
> +          |                        |                       |                               |
> +          |                        |                       |<----MNG_RESET_NOTIFY_ACK----- |
> +          |                        |                       |                               |
> +          |                        |<----ISHTP_START------ |                               |
> +          |                        |                       |                               |
> +          |                        |<-----------------HOST_START_RES_CMD-------------------|
> +          |                        |                       |                               |
> +          |                        |------------------QUERY_SUBSCRIBER-------------------->|
> +          |                        |                       |                               |
> +          |                        |------------------HOST_ENUM_REQ_CMD------------------->|
> +          |                        |                       |                               |
> +          |                        |<-----------------HOST_ENUM_RES_CMD--------------------|
> +          |                        |                       |                               |
> +          |                        |------------------HOST_CLIENT_PROPERTIES_REQ_CMD------>|
> +          |                        |                       |                               |
> +          |                        |<-----------------HOST_CLIENT_PROPERTIES_RES_CMD-------|
> +          |       Create new device on in ishtp bus        |                               |
> +          |                        |                       |                               |
> +          |                        |------------------HOST_CLIENT_PROPERTIES_REQ_CMD------>|
> +          |                        |                       |                               |
> +          |                        |<-----------------HOST_CLIENT_PROPERTIES_RES_CMD-------|
> +          |       Create new device on in ishtp bus        |                               |
> +          |                        |                       |                               |
> +          |                        |--Repeat HOST_CLIENT_PROPERTIES_REQ_CMD-till last one--|
> +          |                        |                       |                               |
> +       probed()
> +          |----ishtp_cl_connect--->|----------------- CLIENT_CONNECT_REQ_CMD-------------->|
> +          |                        |                       |                               |
> +          |                        |<----------------CLIENT_CONNECT_RES_CMD----------------|
> +          |                        |                       |                               |
> +          |register event callback |                       |                               |
> +          |                        |                       |                               |
> +          |ishtp_cl_send(
> +          HOSTIF_DM_ENUM_DEVICES)  |----------fill ishtp_msg_hdr struct write to HW-----  >|
> +          |                        |                       |                               |
> +          |                        |                       |<-----IRQ(IPC_PROTOCOL_ISHTP---|
> +          |                        |                       |                               |
> +          |<--ENUM_DEVICE RSP------|                       |                               |
> +          |                        |                       |                               |
> +  for each enumerated device
> +          |ishtp_cl_send(
> +          HOSTIF_GET_HID_DESCRIPTOR|----------fill ishtp_msg_hdr struct write to HW-----  >|
> +          |                        |                       |                               |
> +          ...Response
> +          |                        |                       |                               |
> +  for each enumerated device
> +          |ishtp_cl_send(
> +       HOSTIF_GET_REPORT_DESCRIPTOR|--------------fill ishtp_msg_hdr struct write to HW-- >|
> +          |                        |                       |                               |
> +          |                        |                       |                               |
> +   hid_allocate_device
> +          |                        |                       |                               |
> +   hid_add_device                  |                       |                               |
> +          |                        |                       |                               |
> +
> +
> +3.7 ISH Debugging
> +-----------------
> +
> +To debug ISH, event tracing mechanism is used. To enable debug logs
> +echo 1 > /sys/kernel/debug/tracing/events/intel_ish/enable
> +cat sys/kernel/debug/tracing/trace
> +
> +3.8 ISH IIO sysfs Example on Lenovo thinkpad Yoga 260
> +-----------------------------------------------------
> +
> +::
> +
> +  root@otcpl-ThinkPad-Yoga-260:~# tree -l /sys/bus/iio/devices/
> +  /sys/bus/iio/devices/
> +  âââ iio:device0 -> ../../../devices/0044:8086:22D8.0001/HID-SENSOR-200073.9.auto/iio:device0
> +  â   âââ buffer
> +  â   â   âââ enable
> +  â   â   âââ length
> +  â   â   âââ watermark
> +  ...
> +  â   âââ in_accel_hysteresis
> +  â   âââ in_accel_offset
> +  â   âââ in_accel_sampling_frequency
> +  â   âââ in_accel_scale
> +  â   âââ in_accel_x_raw
> +  â   âââ in_accel_y_raw
> +  â   âââ in_accel_z_raw
> +  â   âââ name
> +  â   âââ scan_elements
> +  â   â   âââ in_accel_x_en
> +  â   â   âââ in_accel_x_index
> +  â   â   âââ in_accel_x_type
> +  â   â   âââ in_accel_y_en
> +  â   â   âââ in_accel_y_index
> +  â   â   âââ in_accel_y_type
> +  â   â   âââ in_accel_z_en
> +  â   â   âââ in_accel_z_index
> +  â   â   âââ in_accel_z_type
> +  ...
> +  â   â   âââ devices
> +  â   â   â   â   âââ buffer
> +  â   â   â   â   â   âââ enable
> +  â   â   â   â   â   âââ length
> +  â   â   â   â   â   âââ watermark
> +  â   â   â   â   âââ dev
> +  â   â   â   â   âââ in_intensity_both_raw
> +  â   â   â   â   âââ in_intensity_hysteresis
> +  â   â   â   â   âââ in_intensity_offset
> +  â   â   â   â   âââ in_intensity_sampling_frequency
> +  â   â   â   â   âââ in_intensity_scale
> +  â   â   â   â   âââ name
> +  â   â   â   â   âââ scan_elements
> +  â   â   â   â   â   âââ in_intensity_both_en
> +  â   â   â   â   â   âââ in_intensity_both_index
> +  â   â   â   â   â   âââ in_intensity_both_type
> +  â   â   â   â   âââ trigger
> +  â   â   â   â   â   âââ current_trigger
> +  ...
> +  â   â   â   â   âââ buffer
> +  â   â   â   â   â   âââ enable
> +  â   â   â   â   â   âââ length
> +  â   â   â   â   â   âââ watermark
> +  â   â   â   â   âââ dev
> +  â   â   â   â   âââ in_magn_hysteresis
> +  â   â   â   â   âââ in_magn_offset
> +  â   â   â   â   âââ in_magn_sampling_frequency
> +  â   â   â   â   âââ in_magn_scale
> +  â   â   â   â   âââ in_magn_x_raw
> +  â   â   â   â   âââ in_magn_y_raw
> +  â   â   â   â   âââ in_magn_z_raw
> +  â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_raw
> +  â   â   â   â   âââ in_rot_hysteresis
> +  â   â   â   â   âââ in_rot_offset
> +  â   â   â   â   âââ in_rot_sampling_frequency
> +  â   â   â   â   âââ in_rot_scale
> +  â   â   â   â   âââ name
> +  ...
> +  â   â   â   â   âââ scan_elements
> +  â   â   â   â   â   âââ in_magn_x_en
> +  â   â   â   â   â   âââ in_magn_x_index
> +  â   â   â   â   â   âââ in_magn_x_type
> +  â   â   â   â   â   âââ in_magn_y_en
> +  â   â   â   â   â   âââ in_magn_y_index
> +  â   â   â   â   â   âââ in_magn_y_type
> +  â   â   â   â   â   âââ in_magn_z_en
> +  â   â   â   â   â   âââ in_magn_z_index
> +  â   â   â   â   â   âââ in_magn_z_type
> +  â   â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_en
> +  â   â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_index
> +  â   â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_type
> +  â   â   â   â   âââ trigger
> +  â   â   â   â   â   âââ current_trigger
> +  ...
> +  â   â   â   â   âââ buffer
> +  â   â   â   â   â   âââ enable
> +  â   â   â   â   â   âââ length
> +  â   â   â   â   â   âââ watermark
> +  â   â   â   â   âââ dev
> +  â   â   â   â   âââ in_anglvel_hysteresis
> +  â   â   â   â   âââ in_anglvel_offset
> +  â   â   â   â   âââ in_anglvel_sampling_frequency
> +  â   â   â   â   âââ in_anglvel_scale
> +  â   â   â   â   âââ in_anglvel_x_raw
> +  â   â   â   â   âââ in_anglvel_y_raw
> +  â   â   â   â   âââ in_anglvel_z_raw
> +  â   â   â   â   âââ name
> +  â   â   â   â   âââ scan_elements
> +  â   â   â   â   â   âââ in_anglvel_x_en
> +  â   â   â   â   â   âââ in_anglvel_x_index
> +  â   â   â   â   â   âââ in_anglvel_x_type
> +  â   â   â   â   â   âââ in_anglvel_y_en
> +  â   â   â   â   â   âââ in_anglvel_y_index
> +  â   â   â   â   â   âââ in_anglvel_y_type
> +  â   â   â   â   â   âââ in_anglvel_z_en
> +  â   â   â   â   â   âââ in_anglvel_z_index
> +  â   â   â   â   â   âââ in_anglvel_z_type
> +  â   â   â   â   âââ trigger
> +  â   â   â   â   â   âââ current_trigger
> +  ...
> +  â   â   â   â   âââ buffer
> +  â   â   â   â   â   âââ enable
> +  â   â   â   â   â   âââ length
> +  â   â   â   â   â   âââ watermark
> +  â   â   â   â   âââ dev
> +  â   â   â   â   âââ in_anglvel_hysteresis
> +  â   â   â   â   âââ in_anglvel_offset
> +  â   â   â   â   âââ in_anglvel_sampling_frequency
> +  â   â   â   â   âââ in_anglvel_scale
> +  â   â   â   â   âââ in_anglvel_x_raw
> +  â   â   â   â   âââ in_anglvel_y_raw
> +  â   â   â   â   âââ in_anglvel_z_raw
> +  â   â   â   â   âââ name
> +  â   â   â   â   âââ scan_elements
> +  â   â   â   â   â   âââ in_anglvel_x_en
> +  â   â   â   â   â   âââ in_anglvel_x_index
> +  â   â   â   â   â   âââ in_anglvel_x_type
> +  â   â   â   â   â   âââ in_anglvel_y_en
> +  â   â   â   â   â   âââ in_anglvel_y_index
> +  â   â   â   â   â   âââ in_anglvel_y_type
> +  â   â   â   â   â   âââ in_anglvel_z_en
> +  â   â   â   â   â   âââ in_anglvel_z_index
> +  â   â   â   â   â   âââ in_anglvel_z_type
> +  â   â   â   â   âââ trigger
> +  â   â   â   â   â   âââ current_trigger
> +  ...
> diff --git a/Documentation/hid/intel-ish-hid.txt b/Documentation/hid/intel-ish-hid.txt
> deleted file mode 100644
> index d48b21c71ddd..000000000000
> --- a/Documentation/hid/intel-ish-hid.txt
> +++ /dev/null
> @@ -1,454 +0,0 @@
> -Intel Integrated Sensor Hub (ISH)
> -===============================
> -
> -A sensor hub enables the ability to offload sensor polling and algorithm
> -processing to a dedicated low power co-processor. This allows the core
> -processor to go into low power modes more often, resulting in the increased
> -battery life.
> -
> -There are many vendors providing external sensor hubs confirming to HID
> -Sensor usage tables, and used in several tablets, 2 in 1 convertible laptops
> -and embedded products. Linux had this support since Linux 3.9.
> -
> -Intel introduced integrated sensor hubs as a part of the SoC starting from
> -Cherry Trail and now supported on multiple generations of CPU packages. There
> -are many commercial devices already shipped with Integrated Sensor Hubs (ISH).
> -These ISH also comply to HID sensor specification, but the  difference is the
> -transport protocol used for communication. The current external sensor hubs
> -mainly use HID over i2C or USB. But ISH doesn't use either i2c or USB.
> -
> -1. Overview
> -
> -Using a analogy with a usbhid implementation, the ISH follows a similar model
> -for a very high speed communication:
> -
> -       -----------------               ----------------------
> -       |    USB HID    |       -->     |    ISH HID         |
> -       -----------------               ----------------------
> -       -----------------               ----------------------
> -       |  USB protocol |       -->     |    ISH Transport   |
> -       -----------------               ----------------------
> -       -----------------               ----------------------
> -       |  EHCI/XHCI    |       -->     |    ISH IPC         |
> -       -----------------               ----------------------
> -             PCI                                PCI
> -       -----------------               ----------------------
> -        |Host controller|      -->     |    ISH processor   |
> -       -----------------               ----------------------
> -            USB Link
> -       -----------------               ----------------------
> -       | USB End points|       -->     |    ISH Clients     |
> -       -----------------               ----------------------
> -
> -Like USB protocol provides a method for device enumeration, link management
> -and user data encapsulation, the ISH also provides similar services. But it is
> -very light weight tailored to manage and communicate with ISH client
> -applications implemented in the firmware.
> -
> -The ISH allows multiple sensor management applications executing in the
> -firmware. Like USB endpoints the messaging can be to/from a client. As part of
> -enumeration process, these clients are identified. These clients can be simple
> -HID sensor applications, sensor calibration application or senor firmware
> -update application.
> -
> -The implementation model is similar, like USB bus, ISH transport is also
> -implemented as a bus. Each client application executing in the ISH processor
> -is registered as a device on this bus. The driver, which binds each device
> -(ISH HID driver) identifies the device type and registers with the hid core.
> -
> -2. ISH Implementation: Block Diagram
> -
> -        ---------------------------
> -       |  User Space Applications  |
> -        ---------------------------
> -
> -----------------IIO ABI----------------
> -        --------------------------
> -       |  IIO Sensor Drivers     |
> -        --------------------------
> -        --------------------------
> -       |        IIO core         |
> -        --------------------------
> -        --------------------------
> -       |   HID Sensor Hub MFD    |
> -        --------------------------
> -        --------------------------
> -       |       HID Core          |
> -        --------------------------
> -        --------------------------
> -       |   HID over ISH Client   |
> -        --------------------------
> -        --------------------------
> -       |   ISH Transport (ISHTP) |
> -        --------------------------
> -        --------------------------
> -       |      IPC Drivers        |
> -        --------------------------
> -OS
> -----------------   PCI -----------------
> -Hardware + Firmware
> -        ----------------------------
> -       | ISH Hardware/Firmware(FW) |
> -        ----------------------------
> -
> -3. High level processing in above blocks
> -
> -3.1 Hardware Interface
> -
> -The ISH is exposed as "Non-VGA unclassified PCI device" to the host. The PCI
> -product and vendor IDs are changed from different generations of processors. So
> -the source code which enumerate drivers needs to update from generation to
> -generation.
> -
> -3.2 Inter Processor Communication (IPC) driver
> -Location: drivers/hid/intel-ish-hid/ipc
> -
> -The IPC message used memory mapped I/O. The registers are defined in
> -hw-ish-regs.h.
> -
> -3.2.1 IPC/FW message types
> -
> -There are two types of messages, one for management of link and other messages
> -are to and from transport layers.
> -
> -TX and RX of Transport messages
> -
> -A set of memory mapped register offers support of multi byte messages TX and
> -RX (E.g.IPC_REG_ISH2HOST_MSG, IPC_REG_HOST2ISH_MSG). The IPC layer maintains
> -internal queues to sequence messages and send them in order to the FW.
> -Optionally the caller can register handler to get notification of completion.
> -A door bell mechanism is used in messaging to trigger processing in host and
> -client firmware side. When ISH interrupt handler is called, the ISH2HOST
> -doorbell register is used by host drivers to determine that the interrupt
> -is for ISH.
> -
> -Each side has 32 32-bit message registers and a 32-bit doorbell. Doorbell
> -register has the following format:
> -Bits 0..6: fragment length (7 bits are used)
> -Bits 10..13: encapsulated protocol
> -Bits 16..19: management command (for IPC management protocol)
> -Bit 31: doorbell trigger (signal H/W interrupt to the other side)
> -Other bits are reserved, should be 0.
> -
> -3.2.2 Transport layer interface
> -
> -To abstract HW level IPC communication, a set of callbacks are registered.
> -The transport layer uses them to send and receive messages.
> -Refer to  struct ishtp_hw_ops for callbacks.
> -
> -3.3 ISH Transport layer
> -Location: drivers/hid/intel-ish-hid/ishtp/
> -
> -3.3.1 A Generic Transport Layer
> -
> -The transport layer is a bi-directional protocol, which defines:
> -- Set of commands to start, stop, connect, disconnect and flow control
> -(ishtp/hbm.h) for details
> -- A flow control mechanism to avoid buffer overflows
> -
> -This protocol resembles bus messages described in the following document:
> -http://www.intel.com/content/dam/www/public/us/en/documents/technical-\
> -specifications/dcmi-hi-1-0-spec.pdf "Chapter 7: Bus Message Layer"
> -
> -3.3.2 Connection and Flow Control Mechanism
> -
> -Each FW client and a protocol is identified by an UUID. In order to communicate
> -to a FW client, a connection must be established using connect request and
> -response bus messages. If successful, a pair (host_client_id and fw_client_id)
> -will identify the connection.
> -
> -Once connection is established, peers send each other flow control bus messages
> -independently. Every peer may send a message only if it has received a
> -flow-control credit before. Once it sent a message, it may not send another one
> -before receiving the next flow control credit.
> -Either side can send disconnect request bus message to end communication. Also
> -the link will be dropped if major FW reset occurs.
> -
> -3.3.3 Peer to Peer data transfer
> -
> -Peer to Peer data transfer can happen with or without using DMA. Depending on
> -the sensor bandwidth requirement DMA can be enabled by using module parameter
> -ishtp_use_dma under intel_ishtp.
> -
> -Each side (host and FW) manages its DMA transfer memory independently. When an
> -ISHTP client from either host or FW side wants to send something, it decides
> -whether to send over IPC or over DMA; for each transfer the decision is
> -independent. The sending side sends DMA_XFER message when the message is in
> -the respective host buffer (TX when host client sends, RX when FW client
> -sends). The recipient of DMA message responds with DMA_XFER_ACK, indicating
> -the sender that the memory region for that message may be reused.
> -
> -DMA initialization is started with host sending DMA_ALLOC_NOTIFY bus message
> -(that includes RX buffer) and FW responds with DMA_ALLOC_NOTIFY_ACK.
> -Additionally to DMA address communication, this sequence checks capabilities:
> -if thw host doesn't support DMA, then it won't send DMA allocation, so FW can't
> -send DMA; if FW doesn't support DMA then it won't respond with
> -DMA_ALLOC_NOTIFY_ACK, in which case host will not use DMA transfers.
> -Here ISH acts as busmaster DMA controller. Hence when host sends DMA_XFER,
> -it's request to do host->ISH DMA transfer; when FW sends DMA_XFER, it means
> -that it already did DMA and the message resides at host. Thus, DMA_XFER
> -and DMA_XFER_ACK act as ownership indicators.
> -
> -At initial state all outgoing memory belongs to the sender (TX to host, RX to
> -FW), DMA_XFER transfers ownership on the region that contains ISHTP message to
> -the receiving side, DMA_XFER_ACK returns ownership to the sender. A sender
> -needs not wait for previous DMA_XFER to be ack'ed, and may send another message
> -as long as remaining continuous memory in its ownership is enough.
> -In principle, multiple DMA_XFER and DMA_XFER_ACK messages may be sent at once
> -(up to IPC MTU), thus allowing for interrupt throttling.
> -Currently, ISH FW decides to send over DMA if ISHTP message is more than 3 IPC
> -fragments and via IPC otherwise.
> -
> -3.3.4 Ring Buffers
> -
> -When a client initiate a connection, a ring or RX and TX buffers are allocated.
> -The size of ring can be specified by the client. HID client set 16 and 32 for
> -TX and RX buffers respectively. On send request from client, the data to be
> -sent is copied to one of the send ring buffer and scheduled to be sent using
> -bus message protocol. These buffers are required because the FW may have not
> -have processed the last message and may not have enough flow control credits
> -to send. Same thing holds true on receive side and flow control is required.
> -
> -3.3.5 Host Enumeration
> -
> -The host enumeration bus command allow discovery of clients present in the FW.
> -There can be multiple sensor clients and clients for calibration function.
> -
> -To ease in implantation and allow independent driver handle each client
> -this transport layer takes advantage of Linux Bus driver model. Each
> -client is registered as device on the the transport bus (ishtp bus).
> -
> -Enumeration sequence of messages:
> -- Host sends HOST_START_REQ_CMD, indicating that host ISHTP layer is up.
> -- FW responds with HOST_START_RES_CMD
> -- Host sends HOST_ENUM_REQ_CMD (enumerate FW clients)
> -- FW responds with HOST_ENUM_RES_CMD that includes bitmap of available FW
> -client IDs
> -- For each FW ID found in that bitmap host sends
> -HOST_CLIENT_PROPERTIES_REQ_CMD
> -- FW responds with HOST_CLIENT_PROPERTIES_RES_CMD. Properties include UUID,
> -max ISHTP message size, etc.
> -- Once host received properties for that last discovered client, it considers
> -ISHTP device fully functional (and allocates DMA buffers)
> -
> -3.4 HID over ISH Client
> -Location: drivers/hid/intel-ish-hid
> -
> -The ISHTP client driver is responsible for:
> -- enumerate HID devices under FW ISH client
> -- Get Report descriptor
> -- Register with HID core as a LL driver
> -- Process Get/Set feature request
> -- Get input reports
> -
> -3.5 HID Sensor Hub MFD and IIO sensor drivers
> -
> -The functionality in these drivers is the same as an external sensor hub.
> -Refer to
> -Documentation/hid/hid-sensor.txt for HID sensor
> -Documentation/ABI/testing/sysfs-bus-iio for IIO ABIs to user space
> -
> -3.6 End to End HID transport Sequence Diagram
> -
> -HID-ISH-CLN                    ISHTP                   IPC                             HW
> -       |                       |                       |                               |
> -       |                       |                       |-----WAKE UP------------------>|
> -       |                       |                       |                               |
> -       |                       |                       |-----HOST READY--------------->|
> -       |                       |                       |                               |
> -       |                       |                       |<----MNG_RESET_NOTIFY_ACK----- |
> -       |                       |                       |                               |
> -       |                       |<----ISHTP_START------ |                               |
> -       |                       |                       |                               |
> -       |                       |<-----------------HOST_START_RES_CMD-------------------|
> -       |                       |                       |                               |
> -       |                       |------------------QUERY_SUBSCRIBER-------------------->|
> -       |                       |                       |                               |
> -       |                       |------------------HOST_ENUM_REQ_CMD------------------->|
> -       |                       |                       |                               |
> -       |                       |<-----------------HOST_ENUM_RES_CMD--------------------|
> -       |                       |                       |                               |
> -       |                       |------------------HOST_CLIENT_PROPERTIES_REQ_CMD------>|
> -       |                       |                       |                               |
> -       |                       |<-----------------HOST_CLIENT_PROPERTIES_RES_CMD-------|
> -       |       Create new device on in ishtp bus       |                               |
> -       |                       |                       |                               |
> -       |                       |------------------HOST_CLIENT_PROPERTIES_REQ_CMD------>|
> -       |                       |                       |                               |
> -       |                       |<-----------------HOST_CLIENT_PROPERTIES_RES_CMD-------|
> -       |       Create new device on in ishtp bus       |                               |
> -       |                       |                       |                               |
> -       |                       |--Repeat HOST_CLIENT_PROPERTIES_REQ_CMD-till last one--|
> -       |                       |                       |                               |
> -     probed()
> -       |----ishtp_cl_connect-->|----------------- CLIENT_CONNECT_REQ_CMD-------------->|
> -       |                       |                       |                               |
> -       |                       |<----------------CLIENT_CONNECT_RES_CMD----------------|
> -       |                       |                       |                               |
> -       |register event callback|                       |                               |
> -       |                       |                       |                               |
> -       |ishtp_cl_send(
> -       HOSTIF_DM_ENUM_DEVICES) |----------fill ishtp_msg_hdr struct write to HW-----  >|
> -       |                       |                       |                               |
> -       |                       |                       |<-----IRQ(IPC_PROTOCOL_ISHTP---|
> -       |                       |                       |                               |
> -       |<--ENUM_DEVICE RSP-----|                       |                               |
> -       |                       |                       |                               |
> -for each enumerated device
> -       |ishtp_cl_send(
> -       HOSTIF_GET_HID_DESCRIPTOR |----------fill ishtp_msg_hdr struct write to HW---  >|
> -       |                       |                       |                               |
> -       ...Response
> -       |                       |                       |                               |
> -for each enumerated device
> -       |ishtp_cl_send(
> -       HOSTIF_GET_REPORT_DESCRIPTOR |----------fill ishtp_msg_hdr struct write to HW- >|
> -       |                       |                       |                               |
> -       |                       |                       |                               |
> - hid_allocate_device
> -       |                       |                       |                               |
> - hid_add_device                        |                       |                               |
> -       |                       |                       |                               |
> -
> -
> -3.7 ISH Debugging
> -
> -To debug ISH, event tracing mechanism is used. To enable debug logs
> -echo 1 > /sys/kernel/debug/tracing/events/intel_ish/enable
> -cat sys/kernel/debug/tracing/trace
> -
> -3.8 ISH IIO sysfs Example on Lenovo thinkpad Yoga 260
> -
> -root@otcpl-ThinkPad-Yoga-260:~# tree -l /sys/bus/iio/devices/
> -/sys/bus/iio/devices/
> -âââ iio:device0 -> ../../../devices/0044:8086:22D8.0001/HID-SENSOR-200073.9.auto/iio:device0
> -â   âââ buffer
> -â   â   âââ enable
> -â   â   âââ length
> -â   â   âââ watermark
> -...
> -â   âââ in_accel_hysteresis
> -â   âââ in_accel_offset
> -â   âââ in_accel_sampling_frequency
> -â   âââ in_accel_scale
> -â   âââ in_accel_x_raw
> -â   âââ in_accel_y_raw
> -â   âââ in_accel_z_raw
> -â   âââ name
> -â   âââ scan_elements
> -â   â   âââ in_accel_x_en
> -â   â   âââ in_accel_x_index
> -â   â   âââ in_accel_x_type
> -â   â   âââ in_accel_y_en
> -â   â   âââ in_accel_y_index
> -â   â   âââ in_accel_y_type
> -â   â   âââ in_accel_z_en
> -â   â   âââ in_accel_z_index
> -â   â   âââ in_accel_z_type
> -...
> -â   â   âââ devices
> -â   â   â   â   âââ buffer
> -â   â   â   â   â   âââ enable
> -â   â   â   â   â   âââ length
> -â   â   â   â   â   âââ watermark
> -â   â   â   â   âââ dev
> -â   â   â   â   âââ in_intensity_both_raw
> -â   â   â   â   âââ in_intensity_hysteresis
> -â   â   â   â   âââ in_intensity_offset
> -â   â   â   â   âââ in_intensity_sampling_frequency
> -â   â   â   â   âââ in_intensity_scale
> -â   â   â   â   âââ name
> -â   â   â   â   âââ scan_elements
> -â   â   â   â   â   âââ in_intensity_both_en
> -â   â   â   â   â   âââ in_intensity_both_index
> -â   â   â   â   â   âââ in_intensity_both_type
> -â   â   â   â   âââ trigger
> -â   â   â   â   â   âââ current_trigger
> -...
> -â   â   â   â   âââ buffer
> -â   â   â   â   â   âââ enable
> -â   â   â   â   â   âââ length
> -â   â   â   â   â   âââ watermark
> -â   â   â   â   âââ dev
> -â   â   â   â   âââ in_magn_hysteresis
> -â   â   â   â   âââ in_magn_offset
> -â   â   â   â   âââ in_magn_sampling_frequency
> -â   â   â   â   âââ in_magn_scale
> -â   â   â   â   âââ in_magn_x_raw
> -â   â   â   â   âââ in_magn_y_raw
> -â   â   â   â   âââ in_magn_z_raw
> -â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_raw
> -â   â   â   â   âââ in_rot_hysteresis
> -â   â   â   â   âââ in_rot_offset
> -â   â   â   â   âââ in_rot_sampling_frequency
> -â   â   â   â   âââ in_rot_scale
> -â   â   â   â   âââ name
> -...
> -â   â   â   â   âââ scan_elements
> -â   â   â   â   â   âââ in_magn_x_en
> -â   â   â   â   â   âââ in_magn_x_index
> -â   â   â   â   â   âââ in_magn_x_type
> -â   â   â   â   â   âââ in_magn_y_en
> -â   â   â   â   â   âââ in_magn_y_index
> -â   â   â   â   â   âââ in_magn_y_type
> -â   â   â   â   â   âââ in_magn_z_en
> -â   â   â   â   â   âââ in_magn_z_index
> -â   â   â   â   â   âââ in_magn_z_type
> -â   â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_en
> -â   â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_index
> -â   â   â   â   â   âââ in_rot_from_north_magnetic_tilt_comp_type
> -â   â   â   â   âââ trigger
> -â   â   â   â   â   âââ current_trigger
> -...
> -â   â   â   â   âââ buffer
> -â   â   â   â   â   âââ enable
> -â   â   â   â   â   âââ length
> -â   â   â   â   â   âââ watermark
> -â   â   â   â   âââ dev
> -â   â   â   â   âââ in_anglvel_hysteresis
> -â   â   â   â   âââ in_anglvel_offset
> -â   â   â   â   âââ in_anglvel_sampling_frequency
> -â   â   â   â   âââ in_anglvel_scale
> -â   â   â   â   âââ in_anglvel_x_raw
> -â   â   â   â   âââ in_anglvel_y_raw
> -â   â   â   â   âââ in_anglvel_z_raw
> -â   â   â   â   âââ name
> -â   â   â   â   âââ scan_elements
> -â   â   â   â   â   âââ in_anglvel_x_en
> -â   â   â   â   â   âââ in_anglvel_x_index
> -â   â   â   â   â   âââ in_anglvel_x_type
> -â   â   â   â   â   âââ in_anglvel_y_en
> -â   â   â   â   â   âââ in_anglvel_y_index
> -â   â   â   â   â   âââ in_anglvel_y_type
> -â   â   â   â   â   âââ in_anglvel_z_en
> -â   â   â   â   â   âââ in_anglvel_z_index
> -â   â   â   â   â   âââ in_anglvel_z_type
> -â   â   â   â   âââ trigger
> -â   â   â   â   â   âââ current_trigger
> -...
> -â   â   â   â   âââ buffer
> -â   â   â   â   â   âââ enable
> -â   â   â   â   â   âââ length
> -â   â   â   â   â   âââ watermark
> -â   â   â   â   âââ dev
> -â   â   â   â   âââ in_anglvel_hysteresis
> -â   â   â   â   âââ in_anglvel_offset
> -â   â   â   â   âââ in_anglvel_sampling_frequency
> -â   â   â   â   âââ in_anglvel_scale
> -â   â   â   â   âââ in_anglvel_x_raw
> -â   â   â   â   âââ in_anglvel_y_raw
> -â   â   â   â   âââ in_anglvel_z_raw
> -â   â   â   â   âââ name
> -â   â   â   â   âââ scan_elements
> -â   â   â   â   â   âââ in_anglvel_x_en
> -â   â   â   â   â   âââ in_anglvel_x_index
> -â   â   â   â   â   âââ in_anglvel_x_type
> -â   â   â   â   â   âââ in_anglvel_y_en
> -â   â   â   â   â   âââ in_anglvel_y_index
> -â   â   â   â   â   âââ in_anglvel_y_type
> -â   â   â   â   â   âââ in_anglvel_z_en
> -â   â   â   â   â   âââ in_anglvel_z_index
> -â   â   â   â   â   âââ in_anglvel_z_type
> -â   â   â   â   âââ trigger
> -â   â   â   â   â   âââ current_trigger
> -...
> diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.rst
> similarity index 94%
> rename from Documentation/hid/uhid.txt
> rename to Documentation/hid/uhid.rst
> index 958fff945304..b18cb96c885f 100644
> --- a/Documentation/hid/uhid.txt
> +++ b/Documentation/hid/uhid.rst
> @@ -1,5 +1,6 @@
> -      UHID - User-space I/O driver support for HID subsystem
> -     ========================================================
> +======================================================
> +UHID - User-space I/O driver support for HID subsystem
> +======================================================
>
>  UHID allows user-space to implement HID transport drivers. Please see
>  hid-transport.txt for an introduction into HID transport drivers. This document
> @@ -22,9 +23,9 @@ If a new device is detected by your HID I/O Driver and you want to register this
>  device with the HID subsystem, then you need to open /dev/uhid once for each
>  device you want to register. All further communication is done by read()'ing or
>  write()'ing "struct uhid_event" objects. Non-blocking operations are supported
> -by setting O_NONBLOCK.
> +by setting O_NONBLOCK::
>
> -struct uhid_event {
> +  struct uhid_event {
>          __u32 type;
>          union {
>                  struct uhid_create2_req create2;
> @@ -32,7 +33,7 @@ struct uhid_event {
>                  struct uhid_input2_req input2;
>                  ...
>          } u;
> -};
> +  };
>
>  The "type" field contains the ID of the event. Depending on the ID different
>  payloads are sent. You must not split a single event across multiple read()'s or
> @@ -86,31 +87,31 @@ the request was handled successfully. O_NONBLOCK does not affect write() as
>  writes are always handled immediately in a non-blocking fashion. Future requests
>  might make use of O_NONBLOCK, though.
>
> -  UHID_CREATE2:
> +UHID_CREATE2:
>    This creates the internal HID device. No I/O is possible until you send this
>    event to the kernel. The payload is of type struct uhid_create2_req and
>    contains information about your device. You can start I/O now.
>
> -  UHID_DESTROY:
> +UHID_DESTROY:
>    This destroys the internal HID device. No further I/O will be accepted. There
>    may still be pending messages that you can receive with read() but no further
>    UHID_INPUT events can be sent to the kernel.
>    You can create a new device by sending UHID_CREATE2 again. There is no need to
>    reopen the character device.
>
> -  UHID_INPUT2:
> +UHID_INPUT2:
>    You must send UHID_CREATE2 before sending input to the kernel! This event
>    contains a data-payload. This is the raw data that you read from your device
>    on the interrupt channel. The kernel will parse the HID reports.
>
> -  UHID_GET_REPORT_REPLY:
> +UHID_GET_REPORT_REPLY:
>    If you receive a UHID_GET_REPORT request you must answer with this request.
>    You  must copy the "id" field from the request into the answer. Set the "err"
>    field to 0 if no error occurred or to EIO if an I/O error occurred.
>    If "err" is 0 then you should fill the buffer of the answer with the results
>    of the GET_REPORT request and set "size" correspondingly.
>
> -  UHID_SET_REPORT_REPLY:
> +UHID_SET_REPORT_REPLY:
>    This is the SET_REPORT equivalent of UHID_GET_REPORT_REPLY. Unlike GET_REPORT,
>    SET_REPORT never returns a data buffer, therefore, it's sufficient to set the
>    "id" and "err" fields correctly.
> @@ -120,16 +121,18 @@ read()
>  read() will return a queued output report. No reaction is required to any of
>  them but you should handle them according to your needs.
>
> -  UHID_START:
> +UHID_START:
>    This is sent when the HID device is started. Consider this as an answer to
>    UHID_CREATE2. This is always the first event that is sent. Note that this
>    event might not be available immediately after write(UHID_CREATE2) returns.
>    Device drivers might required delayed setups.
>    This event contains a payload of type uhid_start_req. The "dev_flags" field
>    describes special behaviors of a device. The following flags are defined:
> -      UHID_DEV_NUMBERED_FEATURE_REPORTS:
> -      UHID_DEV_NUMBERED_OUTPUT_REPORTS:
> -      UHID_DEV_NUMBERED_INPUT_REPORTS:
> +
> +      - UHID_DEV_NUMBERED_FEATURE_REPORTS
> +      - UHID_DEV_NUMBERED_OUTPUT_REPORTS
> +      - UHID_DEV_NUMBERED_INPUT_REPORTS
> +
>            Each of these flags defines whether a given report-type uses numbered
>            reports. If numbered reports are used for a type, all messages from
>            the kernel already have the report-number as prefix. Otherwise, no
> @@ -137,33 +140,35 @@ them but you should handle them according to your needs.
>            For messages sent by user-space to the kernel, you must adjust the
>            prefixes according to these flags.
>
> -  UHID_STOP:
> +UHID_STOP:
>    This is sent when the HID device is stopped. Consider this as an answer to
>    UHID_DESTROY.
> +
>    If you didn't destroy your device via UHID_DESTROY, but the kernel sends an
>    UHID_STOP event, this should usually be ignored. It means that the kernel
>    reloaded/changed the device driver loaded on your HID device (or some other
>    maintenance actions happened).
> +
>    You can usually ignored any UHID_STOP events safely.
>
> -  UHID_OPEN:
> +UHID_OPEN:
>    This is sent when the HID device is opened. That is, the data that the HID
>    device provides is read by some other process. You may ignore this event but
>    it is useful for power-management. As long as you haven't received this event
>    there is actually no other process that reads your data so there is no need to
>    send UHID_INPUT2 events to the kernel.
>
> -  UHID_CLOSE:
> +UHID_CLOSE:
>    This is sent when there are no more processes which read the HID data. It is
>    the counterpart of UHID_OPEN and you may as well ignore this event.
>
> -  UHID_OUTPUT:
> +UHID_OUTPUT:
>    This is sent if the HID device driver wants to send raw data to the I/O
>    device on the interrupt channel. You should read the payload and forward it to
>    the device. The payload is of type "struct uhid_output_req".
>    This may be received even though you haven't received UHID_OPEN, yet.
>
> -  UHID_GET_REPORT:
> +UHID_GET_REPORT:
>    This event is sent if the kernel driver wants to perform a GET_REPORT request
>    on the control channeld as described in the HID specs. The report-type and
>    report-number are available in the payload.
> @@ -177,11 +182,12 @@ them but you should handle them according to your needs.
>    timed out, the kernel will ignore the response silently. The "id" field is
>    never re-used, so conflicts cannot happen.
>
> -  UHID_SET_REPORT:
> +UHID_SET_REPORT:
>    This is the SET_REPORT equivalent of UHID_GET_REPORT. On receipt, you shall
>    send a SET_REPORT request to your hid device. Once it replies, you must tell
>    the kernel about it via UHID_SET_REPORT_REPLY.
>    The same restrictions as for UHID_GET_REPORT apply.
>
>  ----------------------------------------------------
> +
>  Written 2012, David Herrmann <dh.herrmann@xxxxxxxxx>
> diff --git a/Documentation/input/input.rst b/Documentation/input/input.rst
> index 47f86a4bf16c..0eb61e67a7b7 100644
> --- a/Documentation/input/input.rst
> +++ b/Documentation/input/input.rst
> @@ -188,7 +188,7 @@ LCDs and many other purposes.
>
>  The monitor and speaker controls should be easy to add to the hid/input
>  interface, but for the UPSs and LCDs it doesn't make much sense. For this,
> -the hiddev interface was designed. See Documentation/hid/hiddev.txt
> +the hiddev interface was designed. See Documentation/hid/hiddev.rst
>  for more information about it.
>
>  The usage of the usbhid module is very simple, it takes no parameters,
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3e3b9738f2e6..9458cdaa5b4b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16461,7 +16461,7 @@ M:      Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
>  L:     linux-usb@xxxxxxxxxxxxxxx
>  T:     git git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git
>  S:     Maintained
> -F:     Documentation/hid/hiddev.txt
> +F:     Documentation/hid/hiddev.rst
>  F:     drivers/hid/usbhid/
>
>  USB INTEL XHCI ROLE MUX DRIVER
> --
> 2.21.0
>