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Message-ID: <CAO-hwJK0GEbzK9NVTm2ZBkskYb4Hq7hek++jgSQBWWAg3veS7g@mail.gmail.com>
Date: Tue, 2 Jul 2019 11:58:13 +0200
From: Benjamin Tissoires <benjamin.tissoires@...hat.com>
To: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
Cc: Linux Doc Mailing List <linux-doc@...r.kernel.org>,
Mauro Carvalho Chehab <mchehab@...radead.org>,
lkml <linux-kernel@...r.kernel.org>,
Jonathan Corbet <corbet@....net>,
Jiri Kosina <jikos@...nel.org>,
Jonathan Cameron <jic23@...nel.org>,
Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
Dmitry Torokhov <dmitry.torokhov@...il.com>,
"open list:HID CORE LAYER" <linux-input@...r.kernel.org>,
linux-iio@...r.kernel.org,
Linux USB Mailing List <linux-usb@...r.kernel.org>
Subject: Re: [PATCH 03/43] docs: hid: convert to ReST
On Fri, Jun 28, 2019 at 2:21 PM Mauro Carvalho Chehab
<mchehab+samsung@...nel.org> 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@...nel.org>
> Acked-by: Benjamin Tissoires <benjamin.tissoires@...hat.com>
> ---
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
> + .
> + │ ├── 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 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@...il.com>
> 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@...nal11.us>, 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@...pl-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@...pl-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@...il.com>
> 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@...hat.com>
> L: linux-usb@...r.kernel.org
> 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
>
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