Em Thu, 13 Jun 2019 10:08:34 +0200
Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> escreveu:
> On Wed, Jun 12, 2019 at 8:39 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>
>
> Do you need to take this patch through the doc tree or should we carry
> it in the HID one?
Each patch in this series is pretty much independent. So, feel
free to apply it via 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
> > + .
> > + │ ├── 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
> >
> > 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
> > + │ │ │ ├── 10:53 -> ../HID-SENSOR-2000e1.6.auto
> > + │ ├── 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 3dcba9fd4a3a..6f3aaa86ce7b 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/
> > + ├── iio:device0 -> ../../../devices/0044:8086:22D8.0001/HID-SENSOR-200073.9.auto/iio:device0
> > + │ ├── buffer
> > + │ │ ├── enable
> > + │ │ ├── length
> > + │ │ └── watermark
> > + ...
> > + │ ├── in_accel_hysteresis
> > + │ ├── in_accel_offset
> > + │ ├── in_accel_sampling_frequency
> > + │ ├── in_accel_scale
> > + │ ├── in_accel_x_raw
> > + │ ├── in_accel_y_raw
> > + │ ├── in_accel_z_raw
> > + │ ├── name
> > + │ ├── scan_elements
> > + │ │ ├── in_accel_x_en
> > + │ │ ├── in_accel_x_index
> > + │ │ ├── in_accel_x_type
> > + │ │ ├── in_accel_y_en
> > + │ │ ├── in_accel_y_index
> > + │ │ ├── in_accel_y_type
> > + │ │ ├── in_accel_z_en
> > + │ │ ├── in_accel_z_index
> > + │ │ └── in_accel_z_type
> > + ...
> > + │ │ ├── devices
> > + │ │ │ │ ├── buffer
> > + │ │ │ │ │ ├── enable
> > + │ │ │ │ │ ├── length
> > + │ │ │ │ │ └── watermark
> > + │ │ │ │ ├── dev
> > + │ │ │ │ ├── in_intensity_both_raw
> > + │ │ │ │ ├── in_intensity_hysteresis
> > + │ │ │ │ ├── in_intensity_offset
> > + │ │ │ │ ├── in_intensity_sampling_frequency
> > + │ │ │ │ ├── in_intensity_scale
> > + │ │ │ │ ├── name
> > + │ │ │ │ ├── scan_elements
> > + │ │ │ │ │ ├── in_intensity_both_en
> > + │ │ │ │ │ ├── in_intensity_both_index
> > + │ │ │ │ │ └── in_intensity_both_type
> > + │ │ │ │ ├── trigger
> > + │ │ │ │ │ └── current_trigger
> > + ...
> > + │ │ │ │ ├── buffer
> > + │ │ │ │ │ ├── enable
> > + │ │ │ │ │ ├── length
> > + │ │ │ │ │ └── watermark
> > + │ │ │ │ ├── dev
> > + │ │ │ │ ├── in_magn_hysteresis
> > + │ │ │ │ ├── in_magn_offset
> > + │ │ │ │ ├── in_magn_sampling_frequency
> > + │ │ │ │ ├── in_magn_scale
> > + │ │ │ │ ├── in_magn_x_raw
> > + │ │ │ │ ├── in_magn_y_raw
> > + │ │ │ │ ├── in_magn_z_raw
> > + │ │ │ │ ├── in_rot_from_north_magnetic_tilt_comp_raw
> > + │ │ │ │ ├── in_rot_hysteresis
> > + │ │ │ │ ├── in_rot_offset
> > + │ │ │ │ ├── in_rot_sampling_frequency
> > + │ │ │ │ ├── in_rot_scale
> > + │ │ │ │ ├── name
> > + ...
> > + │ │ │ │ ├── scan_elements
> > + │ │ │ │ │ ├── in_magn_x_en
> > + │ │ │ │ │ ├── in_magn_x_index
> > + │ │ │ │ │ ├── in_magn_x_type
> > + │ │ │ │ │ ├── in_magn_y_en
> > + │ │ │ │ │ ├── in_magn_y_index
> > + │ │ │ │ │ ├── in_magn_y_type
> > + │ │ │ │ │ ├── in_magn_z_en
> > + │ │ │ │ │ ├── in_magn_z_index
> > + │ │ │ │ │ ├── in_magn_z_type
> > + │ │ │ │ │ ├── in_rot_from_north_magnetic_tilt_comp_en
> > + │ │ │ │ │ ├── in_rot_from_north_magnetic_tilt_comp_index
> > + │ │ │ │ │ └── in_rot_from_north_magnetic_tilt_comp_type
> > + │ │ │ │ ├── trigger
> > + │ │ │ │ │ └── current_trigger
> > + ...
> > + │ │ │ │ ├── buffer
> > + │ │ │ │ │ ├── enable
> > + │ │ │ │ │ ├── length
> > + │ │ │ │ │ └── watermark
> > + │ │ │ │ ├── dev
> > + │ │ │ │ ├── in_anglvel_hysteresis
> > + │ │ │ │ ├── in_anglvel_offset
> > + │ │ │ │ ├── in_anglvel_sampling_frequency
> > + │ │ │ │ ├── in_anglvel_scale
> > + │ │ │ │ ├── in_anglvel_x_raw
> > + │ │ │ │ ├── in_anglvel_y_raw
> > + │ │ │ │ ├── in_anglvel_z_raw
> > + │ │ │ │ ├── name
> > + │ │ │ │ ├── scan_elements
> > + │ │ │ │ │ ├── in_anglvel_x_en
> > + │ │ │ │ │ ├── in_anglvel_x_index
> > + │ │ │ │ │ ├── in_anglvel_x_type
> > + │ │ │ │ │ ├── in_anglvel_y_en
> > + │ │ │ │ │ ├── in_anglvel_y_index
> > + │ │ │ │ │ ├── in_anglvel_y_type
> > + │ │ │ │ │ ├── in_anglvel_z_en
> > + │ │ │ │ │ ├── in_anglvel_z_index
> > + │ │ │ │ │ └── in_anglvel_z_type
> > + │ │ │ │ ├── trigger
> > + │ │ │ │ │ └── current_trigger
> > + ...
> > + │ │ │ │ ├── buffer
> > + │ │ │ │ │ ├── enable
> > + │ │ │ │ │ ├── length
> > + │ │ │ │ │ └── watermark
> > + │ │ │ │ ├── dev
> > + │ │ │ │ ├── in_anglvel_hysteresis
> > + │ │ │ │ ├── in_anglvel_offset
> > + │ │ │ │ ├── in_anglvel_sampling_frequency
> > + │ │ │ │ ├── in_anglvel_scale
> > + │ │ │ │ ├── in_anglvel_x_raw
> > + │ │ │ │ ├── in_anglvel_y_raw
> > + │ │ │ │ ├── in_anglvel_z_raw
> > + │ │ │ │ ├── name
> > + │ │ │ │ ├── scan_elements
> > + │ │ │ │ │ ├── in_anglvel_x_en
> > + │ │ │ │ │ ├── in_anglvel_x_index
> > + │ │ │ │ │ ├── in_anglvel_x_type
> > + │ │ │ │ │ ├── in_anglvel_y_en
> > + │ │ │ │ │ ├── in_anglvel_y_index
> > + │ │ │ │ │ ├── in_anglvel_y_type
> > + │ │ │ │ │ ├── in_anglvel_z_en
> > + │ │ │ │ │ ├── in_anglvel_z_index
> > + │ │ │ │ │ └── in_anglvel_z_type
> > + │ │ │ │ ├── trigger
> > + │ │ │ │ │ └── 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/
> > -├── iio:device0 -> ../../../devices/0044:8086:22D8.0001/HID-SENSOR-200073.9.auto/iio:device0
> > -│ ├── buffer
> > -│ │ ├── enable
> > -│ │ ├── length
> > -│ │ └── watermark
> > -...
> > -│ ├── in_accel_hysteresis
> > -│ ├── in_accel_offset
> > -│ ├── in_accel_sampling_frequency
> > -│ ├── in_accel_scale
> > -│ ├── in_accel_x_raw
> > -│ ├── in_accel_y_raw
> > -│ ├── in_accel_z_raw
> > -│ ├── name
> > -│ ├── scan_elements
> > -│ │ ├── in_accel_x_en
> > -│ │ ├── in_accel_x_index
> > -│ │ ├── in_accel_x_type
> > -│ │ ├── in_accel_y_en
> > -│ │ ├── in_accel_y_index
> > -│ │ ├── in_accel_y_type
> > -│ │ ├── in_accel_z_en
> > -│ │ ├── in_accel_z_index
> > -│ │ └── in_accel_z_type
> > -...
> > -│ │ ├── devices
> > -│ │ │ │ ├── buffer
> > -│ │ │ │ │ ├── enable
> > -│ │ │ │ │ ├── length
> > -│ │ │ │ │ └── watermark
> > -│ │ │ │ ├── dev
> > -│ │ │ │ ├── in_intensity_both_raw
> > -│ │ │ │ ├── in_intensity_hysteresis
> > -│ │ │ │ ├── in_intensity_offset
> > -│ │ │ │ ├── in_intensity_sampling_frequency
> > -│ │ │ │ ├── in_intensity_scale
> > -│ │ │ │ ├── name
> > -│ │ │ │ ├── scan_elements
> > -│ │ │ │ │ ├── in_intensity_both_en
> > -│ │ │ │ │ ├── in_intensity_both_index
> > -│ │ │ │ │ └── in_intensity_both_type
> > -│ │ │ │ ├── trigger
> > -│ │ │ │ │ └── current_trigger
> > -...
> > -│ │ │ │ ├── buffer
> > -│ │ │ │ │ ├── enable
> > -│ │ │ │ │ ├── length
> > -│ │ │ │ │ └── watermark
> > -│ │ │ │ ├── dev
> > -│ │ │ │ ├── in_magn_hysteresis
> > -│ │ │ │ ├── in_magn_offset
> > -│ │ │ │ ├── in_magn_sampling_frequency
> > -│ │ │ │ ├── in_magn_scale
> > -│ │ │ │ ├── in_magn_x_raw
> > -│ │ │ │ ├── in_magn_y_raw
> > -│ │ │ │ ├── in_magn_z_raw
> > -│ │ │ │ ├── in_rot_from_north_magnetic_tilt_comp_raw
> > -│ │ │ │ ├── in_rot_hysteresis
> > -│ │ │ │ ├── in_rot_offset
> > -│ │ │ │ ├── in_rot_sampling_frequency
> > -│ │ │ │ ├── in_rot_scale
> > -│ │ │ │ ├── name
> > -...
> > -│ │ │ │ ├── scan_elements
> > -│ │ │ │ │ ├── in_magn_x_en
> > -│ │ │ │ │ ├── in_magn_x_index
> > -│ │ │ │ │ ├── in_magn_x_type
> > -│ │ │ │ │ ├── in_magn_y_en
> > -│ │ │ │ │ ├── in_magn_y_index
> > -│ │ │ │ │ ├── in_magn_y_type
> > -│ │ │ │ │ ├── in_magn_z_en
> > -│ │ │ │ │ ├── in_magn_z_index
> > -│ │ │ │ │ ├── in_magn_z_type
> > -│ │ │ │ │ ├── in_rot_from_north_magnetic_tilt_comp_en
> > -│ │ │ │ │ ├── in_rot_from_north_magnetic_tilt_comp_index
> > -│ │ │ │ │ └── in_rot_from_north_magnetic_tilt_comp_type
> > -│ │ │ │ ├── trigger
> > -│ │ │ │ │ └── current_trigger
> > -...
> > -│ │ │ │ ├── buffer
> > -│ │ │ │ │ ├── enable
> > -│ │ │ │ │ ├── length
> > -│ │ │ │ │ └── watermark
> > -│ │ │ │ ├── dev
> > -│ │ │ │ ├── in_anglvel_hysteresis
> > -│ │ │ │ ├── in_anglvel_offset
> > -│ │ │ │ ├── in_anglvel_sampling_frequency
> > -│ │ │ │ ├── in_anglvel_scale
> > -│ │ │ │ ├── in_anglvel_x_raw
> > -│ │ │ │ ├── in_anglvel_y_raw
> > -│ │ │ │ ├── in_anglvel_z_raw
> > -│ │ │ │ ├── name
> > -│ │ │ │ ├── scan_elements
> > -│ │ │ │ │ ├── in_anglvel_x_en
> > -│ │ │ │ │ ├── in_anglvel_x_index
> > -│ │ │ │ │ ├── in_anglvel_x_type
> > -│ │ │ │ │ ├── in_anglvel_y_en
> > -│ │ │ │ │ ├── in_anglvel_y_index
> > -│ │ │ │ │ ├── in_anglvel_y_type
> > -│ │ │ │ │ ├── in_anglvel_z_en
> > -│ │ │ │ │ ├── in_anglvel_z_index
> > -│ │ │ │ │ └── in_anglvel_z_type
> > -│ │ │ │ ├── trigger
> > -│ │ │ │ │ └── current_trigger
> > -...
> > -│ │ │ │ ├── buffer
> > -│ │ │ │ │ ├── enable
> > -│ │ │ │ │ ├── length
> > -│ │ │ │ │ └── watermark
> > -│ │ │ │ ├── dev
> > -│ │ │ │ ├── in_anglvel_hysteresis
> > -│ │ │ │ ├── in_anglvel_offset
> > -│ │ │ │ ├── in_anglvel_sampling_frequency
> > -│ │ │ │ ├── in_anglvel_scale
> > -│ │ │ │ ├── in_anglvel_x_raw
> > -│ │ │ │ ├── in_anglvel_y_raw
> > -│ │ │ │ ├── in_anglvel_z_raw
> > -│ │ │ │ ├── name
> > -│ │ │ │ ├── scan_elements
> > -│ │ │ │ │ ├── in_anglvel_x_en
> > -│ │ │ │ │ ├── in_anglvel_x_index
> > -│ │ │ │ │ ├── in_anglvel_x_type
> > -│ │ │ │ │ ├── in_anglvel_y_en
> > -│ │ │ │ │ ├── in_anglvel_y_index
> > -│ │ │ │ │ ├── in_anglvel_y_type
> > -│ │ │ │ │ ├── in_anglvel_z_en
> > -│ │ │ │ │ ├── in_anglvel_z_index
> > -│ │ │ │ │ └── in_anglvel_z_type
> > -│ │ │ │ ├── trigger
> > -│ │ │ │ │ └── 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 8d39979e4091..969225e6bfce 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -16383,7 +16383,7 @@ 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
> >
Thanks,
Mauro
