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Commit f8dd50e0 authored by Jiri Kosina's avatar Jiri Kosina
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Merge branch 'for-5.12/doc' into for-linus 

- HID documentation fixes from Randy Dunlap
parents fcd89e77 0603616a
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Documentation/hid/amd-sfh-hid.rst
View file @ f8dd50e0
......@@ -3,13 +3,13 @@
AMD Sensor Fusion Hub
=====================
AMD Sensor Fusion Hub (SFH) is part of an SOC starting from Ryzen based platforms.
AMD Sensor Fusion Hub (SFH) is part of an SOC starting from Ryzen-based platforms.
The solution is working well on several OEM products. AMD SFH uses HID over PCIe bus.
In terms of architecture it resembles ISH, however the major difference is all
the HID reports are generated as part of the kernel driver.
1. Block Diagram
================
Block Diagram
-------------
::
......@@ -45,20 +45,20 @@ the HID reports are generated as part of the kernel driver.
AMD HID Transport Layer
-----------------------
AMD SFH transport is also implemented as a bus. Each client application executing in the AMD MP2 is
registered as a device on this bus. Here: MP2 which is an ARM core connected to x86 for processing
registered as a device on this bus. Here, MP2 is an ARM core connected to x86 for processing
sensor data. The layer, which binds each device (AMD SFH HID driver) identifies the device type and
registers with the hid core. Transport layer attach a constant "struct hid_ll_driver" object with
registers with the HID core. Transport layer attaches a constant "struct hid_ll_driver" object with
each device. Once a device is registered with HID core, the callbacks provided via this struct are
used by HID core to communicate with the device. AMD HID Transport layer implements the synchronous calls.
AMD HID Client Layer
--------------------
This layer is responsible to implement HID request and descriptors. As firmware is OS agnostic, HID
This layer is responsible to implement HID requests and descriptors. As firmware is OS agnostic, HID
client layer fills the HID request structure and descriptors. HID client layer is complex as it is
interface between MP2 PCIe layer and HID. HID client layer initialized the MP2 PCIe layer and holds
the instance of MP2 layer. It identifies the number of sensors connected using MP2-PCIe layer. Base
on that allocates the DRAM address for each and every sensor and pass it to MP2-PCIe driver.On
enumeration of each the sensor, client layer fills the HID Descriptor structure and HID input repor
interface between MP2 PCIe layer and HID. HID client layer initializes the MP2 PCIe layer and holds
the instance of MP2 layer. It identifies the number of sensors connected using MP2-PCIe layer. Based
on that allocates the DRAM address for each and every sensor and passes it to MP2-PCIe driver. On
enumeration of each sensor, client layer fills the HID Descriptor structure and HID input report
structure. HID Feature report structure is optional. The report descriptor structure varies from
sensor to sensor.
......@@ -72,7 +72,7 @@ The communication between X86 and MP2 is split into three parts.
2. Data transfer via DRAM.
3. Supported sensor info via P2C registers.
Commands are sent to MP2 using C2P Mailbox registers. Writing into C2P Message registers generate
Commands are sent to MP2 using C2P Mailbox registers. Writing into C2P Message registers generates
interrupt to MP2. The client layer allocates the physical memory and the same is sent to MP2 via
the PCI layer. MP2 firmware writes the command output to the access DRAM memory which the client
layer has allocated. Firmware always writes minimum of 32 bytes into DRAM. So as a protocol driver
......
Documentation/hid/hid-alps.rst
View file @ f8dd50e0
......@@ -64,7 +64,7 @@ Case2 ReportID_3 TP Absolute
Command Read/Write
------------------
To read/write to RAM, need to send a commands to the device.
To read/write to RAM, need to send a command to the device.
The command format is as below.
......@@ -80,7 +80,7 @@ Byte6 Value Byte
Byte7 Checksum
===== ======================
Command Byte is read=0xD1/write=0xD2 .
Command Byte is read=0xD1/write=0xD2.
Address is read/write RAM address.
......
Documentation/hid/hid-sensor.rst
View file @ f8dd50e0
......@@ -48,12 +48,12 @@ for different sensors. For example an accelerometer can send X,Y and Z data, whe
an ambient light sensor can send illumination data.
So the implementation has two parts:
- Core hid driver
- Core HID driver
- Individual sensor processing part (sensor drivers)
Core driver
-----------
The core driver registers (hid-sensor-hub) registers as a HID driver. It parses
The core driver (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).
......@@ -95,14 +95,14 @@ Registration functions::
u32 usage_id,
struct hid_sensor_hub_callbacks *usage_callback):
Registers callbacks for an usage id. The callback functions are not allowed
Registers callbacks for a usage id. The callback functions are not allowed
to sleep::
int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
u32 usage_id):
Removes callbacks for an usage id.
Removes callbacks for a usage id.
Parsing function::
......@@ -166,7 +166,7 @@ This allows some differentiating use cases, where vendor can provide application
Some common use cases are debug other sensors or to provide some events like
keyboard attached/detached or lid open/close.
To allow application to utilize these sensors, here they are exported uses sysfs
To allow application to utilize these sensors, here they are exported using sysfs
attribute groups, attributes and misc device interface.
An example of this representation on sysfs::
......@@ -207,9 +207,9 @@ An example of this representation on sysfs::
│   │   │   ├── input-1-200202-units
│   │   │   ├── input-1-200202-value
Here there is a custom sensors with four fields, two feature and two inputs.
Here there is a custom sensor 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.
are read only. The value field is a read-write field.
Example::
......@@ -237,6 +237,6 @@ These reports are pushed using misc device interface in a FIFO order::
│   │   │   ├── 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
Each report can be of variable length preceded by a header. This header
consists of a 32-bit usage id, 64-bit time stamp and 32-bit length field of raw
data.
Documentation/hid/hid-transport.rst
View file @ f8dd50e0
......@@ -12,8 +12,8 @@ Bluetooth, I2C and user-space I/O drivers.
The HID subsystem is designed as a bus. Any I/O subsystem may provide HID
devices and register them with the HID bus. HID core then loads generic device
drivers on top of it. The transport drivers are responsible of raw data
transport and device setup/management. HID core is responsible of
drivers on top of it. The transport drivers are responsible for raw data
transport and device setup/management. HID core is responsible for
report-parsing, report interpretation and the user-space API. Device specifics
and quirks are handled by all layers depending on the quirk.
......@@ -67,7 +67,7 @@ Transport drivers attach a constant "struct hid_ll_driver" object with each
device. Once a device is registered with HID core, the callbacks provided via
this struct are used by HID core to communicate with the device.
Transport drivers are responsible of detecting device failures and unplugging.
Transport drivers are responsible for detecting device failures and unplugging.
HID core will operate a device as long as it is registered regardless of any
device failures. Once transport drivers detect unplug or failure events, they
must unregister the device from HID core and HID core will stop using the
......@@ -101,7 +101,7 @@ properties in common.
channel. Any unrequested incoming or outgoing data report must be sent on
this channel and is never acknowledged by the remote side. Devices usually
send their input events on this channel. Outgoing events are normally
not send via intr, except if high throughput is required.
not sent via intr, except if high throughput is required.
- Control Channel (ctrl): The ctrl channel is used for synchronous requests and
device management. Unrequested data input events must not be sent on this
channel and are normally ignored. Instead, devices only send management
......@@ -161,7 +161,7 @@ allowed on the intr channel and are the only means of data there.
payload may be blocked by the underlying transport driver if the
specification does not allow them.
- SET_REPORT: A SET_REPORT request has a report ID plus data as payload. It is
sent from host to device and a device must update it's current report state
sent from host to device and a device must update its current report state
according to the given data. Any of the 3 report types can be used. However,
INPUT reports as payload might be blocked by the underlying transport driver
if the specification does not allow them.
......@@ -294,7 +294,7 @@ The available HID callbacks are:
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
Send a 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.
......
Documentation/hid/hiddev.rst
View file @ f8dd50e0
......@@ -27,7 +27,7 @@ the following::
--> 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
events into the input subsystem, but these have no effect on the HID
device interface.
Using the HID Device Interface
......@@ -73,7 +73,7 @@ The hiddev API uses a read() interface, and a set of ioctl() calls.
HID devices exchange data with the host computer using data
bundles called "reports". Each report is divided into "fields",
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.
each one of these usages has a single signed 32-bit value.
read():
-------
......@@ -113,7 +113,7 @@ HIDIOCAPPLICATION
- (none)
This ioctl call returns the HID application usage associated with the
hid device. The third argument to ioctl() specifies which application
HID device. The third argument to ioctl() specifies which application
index to get. This is useful when the device has more than one
application collection. If the index is invalid (greater or equal to
the number of application collections this device has) the ioctl
......@@ -181,7 +181,7 @@ 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
report id as reported by the device -- or relative --
HID_REPORT_ID_FIRST for the first report, and (HID_REPORT_ID_NEXT |
report_id) for the next report after report_id. Without a-priori
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
......@@ -200,7 +200,7 @@ 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
its report type, report id, field index, and index within the
field have already been filled into the structure.
HIDIOCGUSAGE
......
Documentation/hid/hidraw.rst
View file @ f8dd50e0
......@@ -21,7 +21,7 @@ Hidraw is the only alternative, short of writing a custom kernel driver, for
these non-conformant devices.
A benefit of hidraw is that its use by userspace applications is independent
of the underlying hardware type. Currently, Hidraw is implemented for USB
of the underlying hardware type. Currently, hidraw is implemented for USB
and Bluetooth. In the future, as new hardware bus types are developed which
use the HID specification, hidraw will be expanded to add support for these
new bus types.
......@@ -31,9 +31,10 @@ create hidraw device nodes. Udev will typically create the device nodes
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:
working example at::
http://www.signal11.us/oss/udev/
https://web.archive.org/web/2019*/www.signal11.us
The HIDRAW API
---------------
......
Documentation/hid/intel-ish-hid.rst
View file @ f8dd50e0
......@@ -4,19 +4,19 @@ 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
processor to go into low power modes more often, resulting in 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.
There are many vendors providing external sensor hubs conforming to HID
Sensor usage tables. These may be found in tablets, 2-in-1 convertible laptops
and embedded products. Linux has 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
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.
mainly use HID over I2C or USB. But ISH doesn't use either I2C or USB.
1. Overview
===========
......@@ -35,7 +35,7 @@ for a very high speed communication::
----------------- ----------------------
PCI PCI
----------------- ----------------------
|Host controller| --> | ISH processor |
|Host controller| --> | ISH processor |
----------------- ----------------------
USB Link
----------------- ----------------------
......@@ -50,13 +50,13 @@ 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.
HID sensor applications, sensor calibration applications or sensor firmware
update applications.
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.
(ISH HID driver) identifies the device type and registers with the HID core.
2. ISH Implementation: Block Diagram
====================================
......@@ -104,7 +104,7 @@ is registered as a device on this bus. The driver, which binds each device
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
the source code which enumerates drivers needs to update from generation to
generation.
3.2 Inter Processor Communication (IPC) driver
......@@ -112,41 +112,42 @@ generation.
Location: drivers/hid/intel-ish-hid/ipc
The IPC message used memory mapped I/O. The registers are defined in
The IPC message uses 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.
There are two types of messages, one for management of link and another for
messages 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.
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 firmware.
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
A doorbell 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.
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.
To abstract HW level IPC communication, a set of callbacks is registered.
The transport layer uses them to send and receive messages.
Refer to struct ishtp_hw_ops for callbacks.
Refer to struct ishtp_hw_ops for callbacks.
3.3 ISH Transport layer
-----------------------
......@@ -158,7 +159,7 @@ Location: drivers/hid/intel-ish-hid/ishtp/
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
(see ishtp/hbm.h for details)
- A flow control mechanism to avoid buffer overflows
This protocol resembles bus messages described in the following document:
......@@ -168,14 +169,14 @@ 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
Each FW client and a protocol is identified by a 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
flow-control credit before. Once it has 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.
......@@ -209,7 +210,7 @@ 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
need 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.
......@@ -219,8 +220,8 @@ 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
When a client initiates a connection, a ring of RX and TX buffers is allocated.
The size of ring can be specified by the client. HID client sets 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
......@@ -230,10 +231,10 @@ 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.
The host enumeration bus command allows 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
To ease implementation and allow independent drivers to handle each client,
this transport layer takes advantage of Linux Bus driver model. Each
client is registered as device on the transport bus (ishtp bus).
......@@ -270,7 +271,7 @@ The ISHTP client driver is responsible for:
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
Documentation/ABI/testing/sysfs-bus-iio for IIO ABIs to user space.
3.6 End to End HID transport Sequence Diagram
---------------------------------------------
......@@ -341,9 +342,10 @@ Documentation/ABI/testing/sysfs-bus-iio for IIO ABIs to user space
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
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
-----------------------------------------------------
......
Documentation/hid/uhid.rst
View file @ f8dd50e0
......@@ -3,7 +3,7 @@ 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
hid-transport.rst for an introduction into HID transport drivers. This document
relies heavily on the definitions declared there.
With UHID, a user-space transport driver can create kernel hid-devices for each
......@@ -15,7 +15,7 @@ There is an example user-space application in ./samples/uhid/uhid-example.c
The UHID API
------------
UHID is accessed through a character misc-device. The minor-number is allocated
UHID is accessed through a character misc-device. The minor number is allocated
dynamically so you need to rely on udev (or similar) to create the device node.
This is /dev/uhid by default.
......@@ -45,23 +45,23 @@ The "type" field defines the payload. For each type, there is a
payload-structure available in the union "u" (except for empty payloads). This
payload contains management and/or device data.
The first thing you should do is sending an UHID_CREATE2 event. This will
register the device. UHID will respond with an UHID_START event. You can now
The first thing you should do is send a UHID_CREATE2 event. This will
register the device. UHID will respond with a UHID_START event. You can now
start sending data to and reading data from UHID. However, unless UHID sends the
UHID_OPEN event, the internally attached HID Device Driver has no user attached.
That is, you might put your device asleep unless you receive the UHID_OPEN
event. If you receive the UHID_OPEN event, you should start I/O. If the last
user closes the HID device, you will receive an UHID_CLOSE event. This may be
followed by an UHID_OPEN event again and so on. There is no need to perform
user closes the HID device, you will receive a UHID_CLOSE event. This may be
followed by a UHID_OPEN event again and so on. There is no need to perform
reference-counting in user-space. That is, you will never receive multiple
UHID_OPEN events without an UHID_CLOSE event. The HID subsystem performs
UHID_OPEN events without a UHID_CLOSE event. The HID subsystem performs
ref-counting for you.
You may decide to ignore UHID_OPEN/UHID_CLOSE, though. I/O is allowed even
though the device may have no users.
If you want to send data on the interrupt channel to the HID subsystem, you send
an HID_INPUT2 event with your raw data payload. If the kernel wants to send data
on the interrupt channel to the device, you will read an UHID_OUTPUT event.
a HID_INPUT2 event with your raw data payload. If the kernel wants to send data
on the interrupt channel to the device, you will read a UHID_OUTPUT event.
Data requests on the control channel are currently limited to GET_REPORT and
SET_REPORT (no other data reports on the control channel are defined so far).
Those requests are always synchronous. That means, the kernel sends
......@@ -71,7 +71,7 @@ the response via UHID_GET_REPORT_REPLY and UHID_SET_REPORT_REPLY to the kernel.
The kernel blocks internal driver-execution during such round-trips (times out
after a hard-coded period).
If your device disconnects, you should send an UHID_DESTROY event. This will
If your device disconnects, you should send a UHID_DESTROY event. This will
unregister the device. You can now send UHID_CREATE2 again to register a new
device.
If you close() the fd, the device is automatically unregistered and destroyed
......@@ -125,7 +125,7 @@ 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.
Device drivers might require 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:
......@@ -149,7 +149,7 @@ UHID_STOP:
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.
You can usually ignore any UHID_STOP events safely.
UHID_OPEN:
This is sent when the HID device is opened. That is, the data that the HID
......@@ -166,17 +166,17 @@ 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.
This may be received even though you haven't received UHID_OPEN yet.
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
on the control channel as described in the HID specs. The report-type and
report-number are available in the payload.
The kernel serializes GET_REPORT requests so there will never be two in
parallel. However, if you fail to respond with a UHID_GET_REPORT_REPLY, the
request might silently time out.
Once you read a GET_REPORT request, you shall forward it to the hid device and
remember the "id" field in the payload. Once your hid device responds to the
Once you read a GET_REPORT request, you shall forward it to the HID device and
remember the "id" field in the payload. Once your HID device responds to the
GET_REPORT (or if it fails), you must send a UHID_GET_REPORT_REPLY to the
kernel with the exact same "id" as in the request. If the request already
timed out, the kernel will ignore the response silently. The "id" field is
......@@ -184,7 +184,7 @@ UHID_GET_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
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.
......
drivers/hid/hid-quirks.c
View file @ f8dd50e0
......@@ -1029,7 +1029,7 @@ static DEFINE_MUTEX(dquirks_lock);
/* Runtime ("dynamic") quirks manipulation functions */
/**
* hid_exists_dquirk: find any dynamic quirks for a HID device
* hid_exists_dquirk - find any dynamic quirks for a HID device
* @hdev: the HID device to match
*
* Description:
......@@ -1037,7 +1037,7 @@ static DEFINE_MUTEX(dquirks_lock);
* the pointer to the relevant struct hid_device_id if found.
* Must be called with a read lock held on dquirks_lock.
*
* Returns: NULL if no quirk found, struct hid_device_id * if found.
* Return: NULL if no quirk found, struct hid_device_id * if found.
*/
static struct hid_device_id *hid_exists_dquirk(const struct hid_device *hdev)
{
......@@ -1061,7 +1061,7 @@ static struct hid_device_id *hid_exists_dquirk(const struct hid_device *hdev)
/**
* hid_modify_dquirk: add/replace a HID quirk
* hid_modify_dquirk - add/replace a HID quirk
* @id: the HID device to match
* @quirks: the unsigned long quirks value to add/replace
*
......@@ -1070,7 +1070,7 @@ static struct hid_device_id *hid_exists_dquirk(const struct hid_device *hdev)
* quirks value with what was provided. Otherwise, add the quirk
* to the dynamic quirks list.
*
* Returns: 0 OK, -error on failure.
* Return: 0 OK, -error on failure.
*/
static int hid_modify_dquirk(const struct hid_device_id *id,
const unsigned long quirks)
......@@ -1122,7 +1122,7 @@ static int hid_modify_dquirk(const struct hid_device_id *id,
}
/**
* hid_remove_all_dquirks: remove all runtime HID quirks from memory
* hid_remove_all_dquirks - remove all runtime HID quirks from memory
* @bus: bus to match against. Use HID_BUS_ANY if all need to be removed.
*
* Description:
......@@ -1146,7 +1146,10 @@ static void hid_remove_all_dquirks(__u16 bus)
}
/**
* hid_quirks_init: apply HID quirks specified at module load time
* hid_quirks_init - apply HID quirks specified at module load time
* @quirks_param: array of quirks strings (vendor:product:quirks)
* @bus: bus type
* @count: number of quirks to check
*/
int hid_quirks_init(char **quirks_param, __u16 bus, int count)
{
......@@ -1177,7 +1180,7 @@ int hid_quirks_init(char **quirks_param, __u16 bus, int count)
EXPORT_SYMBOL_GPL(hid_quirks_init);
/**
* hid_quirks_exit: release memory associated with dynamic_quirks
* hid_quirks_exit - release memory associated with dynamic_quirks
* @bus: a bus to match against
*
* Description:
......@@ -1194,14 +1197,14 @@ void hid_quirks_exit(__u16 bus)
EXPORT_SYMBOL_GPL(hid_quirks_exit);
/**
* hid_gets_squirk: return any static quirks for a HID device
* hid_gets_squirk - return any static quirks for a HID device
* @hdev: the HID device to match
*
* Description:
* Given a HID device, return a pointer to the quirked hid_device_id entry
* associated with that device.
*
* Returns: the quirks.
* Return: the quirks.
*/
static unsigned long hid_gets_squirk(const struct hid_device *hdev)
{
......@@ -1225,13 +1228,13 @@ static unsigned long hid_gets_squirk(const struct hid_device *hdev)
}
/**
* hid_lookup_quirk: return any quirks associated with a HID device
* hid_lookup_quirk - return any quirks associated with a HID device
* @hdev: the HID device to look for
*
* Description:
* Given a HID device, return any quirks associated with that device.
*
* Returns: an unsigned long quirks value.
* Return: an unsigned long quirks value.
*/
unsigned long hid_lookup_quirk(const struct hid_device *hdev)
{
......
include/linux/hid-sensor-hub.h
View file @ f8dd50e0
......@@ -150,7 +150,7 @@ int sensor_hub_remove_callback(struct hid_sensor_hub_device *hsdev,
* @info: return information about attribute after parsing report
*
* Parses report and returns the attribute information such as report id,
* field index, units and exponet etc.
* field index, units and exponent etc.
*/
int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
u8 type,
......@@ -167,7 +167,7 @@ int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
* @is_signed: If true then fields < 32 bits will be sign-extended
*
* Issues a synchronous or asynchronous read request for an input attribute.
* Returns data upto 32 bits.
* Return: data up to 32 bits.
*/
enum sensor_hub_read_flags {
......@@ -205,8 +205,9 @@ int sensor_hub_set_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
* @buffer: buffer to copy output
*
* Used to get a field in feature report. For example this can get polling
* interval, sensitivity, activate/deactivate state. On success it returns
* number of bytes copied to buffer. On failure, it returns value < 0.
* interval, sensitivity, activate/deactivate state.
* Return: On success, it returns the number of bytes copied to buffer.
* On failure, it returns value < 0.
*/
int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
u32 field_index, int buffer_size, void *buffer);
......
include/linux/hid.h
View file @ f8dd50e0
......@@ -918,7 +918,7 @@ __u32 hid_field_extract(const struct hid_device *hid, __u8 *report,
/**
* hid_device_io_start - enable HID input during probe, remove
*
* @hid - the device
* @hid: the device
*
* This should only be called during probe or remove and only be
* called by the thread calling probe or remove. It will allow
......@@ -936,7 +936,7 @@ static inline void hid_device_io_start(struct hid_device *hid) {
/**
* hid_device_io_stop - disable HID input during probe, remove
*
* @hid - the device
* @hid: the device
*
* Should only be called after hid_device_io_start. It will prevent
* incoming packets from going to the driver for the duration of
......@@ -1010,6 +1010,13 @@ static inline void hid_map_usage(struct hid_input *hidinput,
/**
* hid_map_usage_clear - map usage input bits and clear the input bit
*
* @hidinput: hidinput which we are interested in
* @usage: usage to fill in
* @bit: pointer to input->{}bit (out parameter)
* @max: maximal valid usage->code to consider later (out parameter)
* @type: input event type (EV_KEY, EV_REL, ...)
* @c: code which corresponds to this usage and type
*
* The same as hid_map_usage, except the @c bit is also cleared in supported
* bits (@bit).
*/
......@@ -1084,7 +1091,7 @@ static inline void hid_hw_request(struct hid_device *hdev,
* @rtype: HID report type
* @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
*
* @return: count of data transfered, negative if error
* Return: count of data transferred, negative if error
*
* Same behavior as hid_hw_request, but with raw buffers instead.
*/
......@@ -1106,7 +1113,7 @@ static inline int hid_hw_raw_request(struct hid_device *hdev,
* @buf: raw data to transfer
* @len: length of buf
*
* @return: count of data transfered, negative if error
* Return: count of data transferred, negative if error
*/
static inline int hid_hw_output_report(struct hid_device *hdev, __u8 *buf,
size_t len)
......
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