Commit e2460b1d authored by Markus Heiser's avatar Markus Heiser Committed by Mauro Carvalho Chehab

[media] doc-rst: linux_tv CEC part, DocBook to reST migration

This is the reST migration of media's CEC part.  The migration is based
on media_tree's cec branch:

 https://git.linuxtv.org/media_tree.git

 c7169ad5 * cec media_tree/cec [media] DocBook/media: add CEC documentation
Signed-off-by: default avatarMarkus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 4606ce43
......@@ -37,21 +37,23 @@ A typical media device hardware is shown at
Typical Media Device
The media infrastructure API was designed to control such devices. It is
divided into four parts.
divided into five parts.
The :Ref:`first part <v4l2spec>` covers radio, video capture and output,
The :ref:`first part <v4l2spec>` covers radio, video capture and output,
cameras, analog TV devices and codecs.
The :Ref:`second part <dvbapi>` covers the API used for digital TV and
The :ref:`second part <dvbapi>` covers the API used for digital TV and
Internet reception via one of the several digital tv standards. While it
is called as DVB API, in fact it covers several different video
standards including DVB-T/T2, DVB-S/S2, DVB-C, ATSC, ISDB-T, ISDB-S,
DTMB, etc. The complete list of supported standards can be found at
:ref:`fe-delivery-system-t`.
The :Ref:`third part <remote_controllers>` covers the Remote Controller API.
The :ref:`third part <remote_controllers>` covers the Remote Controller API.
The :Ref:`fourth part <media_controller>` covers the Media Controller API.
The :ref:`fourth part <media_controller>` covers the Media Controller API.
The :ref:`fifth part <cec>` covers the CEC (Consumer Electronics Control) API.
It should also be noted that a media device may also have audio
components, like mixers, PCM capture, PCM playback, etc, which are
......@@ -72,6 +74,7 @@ etc, please mail to:
uapi/dvb/dvbapi
uapi/rc/remote_controllers
uapi/mediactl/media-controller
uapi/cec/cec-api
uapi/gen-errors
uapi/fdl-appendix
......
.. -*- coding: utf-8; mode: rst -*-
.. _cec:
#######
CEC API
#######
.. _cec-api:
*********************************
CEC: Consumer Electronics Control
*********************************
.. _cec-intro:
Introduction
============
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
HDMI connectors provide a single pin for use by the Consumer Electronics
Control protocol. This protocol allows different devices connected by an
HDMI cable to communicate. The protocol for CEC version 1.4 is defined
in supplements 1 (CEC) and 2 (HEAC or HDMI Ethernet and Audio Return
Channel) of the HDMI 1.4a (:ref:`hdmi`) specification and the
extensions added to CEC version 2.0 are defined in chapter 11 of the
HDMI 2.0 (:ref:`hdmi2`) specification.
The bitrate is very slow (effectively no more than 36 bytes per second)
and is based on the ancient AV.link protocol used in old SCART
connectors. The protocol closely resembles a crazy Rube Goldberg
contraption and is an unholy mix of low and high level messages. Some
messages, especially those part of the HEAC protocol layered on top of
CEC, need to be handled by the kernel, others can be handled either by
the kernel or by userspace.
In addition, CEC can be implemented in HDMI receivers, transmitters and
in USB devices that have an HDMI input and an HDMI output and that
control just the CEC pin.
Drivers that support CEC will create a CEC device node (/dev/cecX) to
give userspace access to the CEC adapter. The
:ref:`CEC_ADAP_G_CAPS <cec-ioc-adap-g-caps>` ioctl will tell
userspace what it is allowed to do.
.. _cec-user-func:
******************
Function Reference
******************
.. toctree::
:maxdepth: 1
cec-func-open
cec-func-close
cec-func-ioctl
cec-func-poll
cec-ioc-adap-g-caps
cec-ioc-adap-g-log-addrs
cec-ioc-adap-g-phys-addr
cec-ioc-dqevent
cec-ioc-g-mode
cec-ioc-receive
**********************
Revision and Copyright
**********************
:author: Verkuil Hans
:address: hans.verkuil@cisco.com
:contrib: Initial version.
**Copyright** 2016 : Hans Verkuil
:revision: 1.0.0 / 2016-03-17 (*hv*)
Initial revision
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-func-close:
***********
cec close()
***********
*man cec-close(2)*
Close a cec device
Synopsis
========
.. code-block:: c
#include <unistd.h>
.. c:function:: int close( int fd )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <func-open>`.
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
Closes the cec device. Resources associated with the file descriptor are
freed. The device configuration remain unchanged.
Return Value
============
:c:func:`close()` returns 0 on success. On error, -1 is returned, and
``errno`` is set appropriately. Possible error codes are:
EBADF
``fd`` is not a valid open file descriptor.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-func-ioctl:
***********
cec ioctl()
***********
*man cec-ioctl(2)*
Control a cec device
Synopsis
========
.. code-block:: c
#include <sys/ioctl.h>
.. c:function:: int ioctl( int fd, int request, void *argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <func-open>`.
``request``
CEC ioctl request code as defined in the cec.h header file, for
example CEC_ADAP_G_CAPS.
``argp``
Pointer to a request-specific structure.
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
The :c:func:`ioctl()` function manipulates cec device parameters. The
argument ``fd`` must be an open file descriptor.
The ioctl ``request`` code specifies the cec function to be called. It
has encoded in it whether the argument is an input, output or read/write
parameter, and the size of the argument ``argp`` in bytes.
Macros and structures definitions specifying cec ioctl requests and
their parameters are located in the cec.h header file. All cec ioctl
requests, their respective function and parameters are specified in
:ref:`cec-user-func`.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
Request-specific error codes are listed in the individual requests
descriptions.
When an ioctl that takes an output or read/write parameter fails, the
parameter remains unmodified.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-func-open:
**********
cec open()
**********
*man cec-open(2)*
Open a cec device
Synopsis
========
.. code-block:: c
#include <fcntl.h>
.. c:function:: int open( const char *device_name, int flags )
Arguments
=========
``device_name``
Device to be opened.
``flags``
Open flags. Access mode must be ``O_RDWR``.
When the ``O_NONBLOCK`` flag is given, the
:ref:`CEC_RECEIVE <cec-ioc-receive>` ioctl will return EAGAIN
error code when no message is available, and the
:ref:`CEC_TRANSMIT <cec-ioc-receive>`,
:ref:`CEC_ADAP_S_PHYS_ADDR <cec-ioc-adap-g-phys-addr>` and
:ref:`CEC_ADAP_S_LOG_ADDRS <cec-ioc-adap-g-log-addrs>` ioctls
all act in non-blocking mode.
Other flags have no effect.
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
To open a cec device applications call :c:func:`open()` with the
desired device name. The function has no side effects; the device
configuration remain unchanged.
When the device is opened in read-only mode, attempts to modify its
configuration will result in an error, and ``errno`` will be set to
EBADF.
Return Value
============
:c:func:`open()` returns the new file descriptor on success. On error,
-1 is returned, and ``errno`` is set appropriately. Possible error codes
include:
EACCES
The requested access to the file is not allowed.
EMFILE
The process already has the maximum number of files open.
ENFILE
The system limit on the total number of open files has been reached.
ENOMEM
Insufficient kernel memory was available.
ENXIO
No device corresponding to this device special file exists.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-func-poll:
**********
cec poll()
**********
*man cec-poll(2)*
Wait for some event on a file descriptor
Synopsis
========
.. code-block:: c
#include <sys/poll.h>
.. c:function:: int poll( struct pollfd *ufds, unsigned int nfds, int timeout )
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
With the :c:func:`poll()` function applications can wait for CEC
events.
On success :c:func:`poll()` returns the number of file descriptors
that have been selected (that is, file descriptors for which the
``revents`` field of the respective :c:type:`struct pollfd` structure
is non-zero). CEC devices set the ``POLLIN`` and ``POLLRDNORM`` flags in
the ``revents`` field if there are messages in the receive queue. If the
transmit queue has room for new messages, the ``POLLOUT`` and
``POLLWRNORM`` flags are set. If there are events in the event queue,
then the ``POLLPRI`` flag is set. When the function timed out it returns
a value of zero, on failure it returns -1 and the ``errno`` variable is
set appropriately.
For more details see the :c:func:`poll()` manual page.
Return Value
============
On success, :c:func:`poll()` returns the number structures which have
non-zero ``revents`` fields, or zero if the call timed out. On error -1
is returned, and the ``errno`` variable is set appropriately:
EBADF
One or more of the ``ufds`` members specify an invalid file
descriptor.
EFAULT
``ufds`` references an inaccessible memory area.
EINTR
The call was interrupted by a signal.
EINVAL
The ``nfds`` argument is greater than ``OPEN_MAX``.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-ioc-adap-g-caps:
*********************
ioctl CEC_ADAP_G_CAPS
*********************
*man CEC_ADAP_G_CAPS(2)*
Query device capabilities
Synopsis
========
.. c:function:: int ioctl( int fd, int request, struct cec_caps *argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <cec-func-open>`.
``request``
CEC_ADAP_G_CAPS
``argp``
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
All cec devices must support the ``CEC_ADAP_G_CAPS`` ioctl. To query
device information, applications call the ioctl with a pointer to a
struct :ref:`cec_caps <cec-caps>`. The driver fills the structure and
returns the information to the application. The ioctl never fails.
.. _cec-caps:
.. flat-table:: struct cec_caps
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- char
- ``driver[32]``
- The name of the cec adapter driver.
- .. row 2
- char
- ``name[32]``
- The name of this CEC adapter. The combination ``driver`` and
``name`` must be unique.
- .. row 3
- __u32
- ``capabilities``
- The capabilities of the CEC adapter, see
:ref:`cec-capabilities`.
- .. row 4
- __u32
- ``version``
- CEC Framework API version, formatted with the ``KERNEL_VERSION()``
macro.
.. _cec-capabilities:
.. flat-table:: CEC Capabilities Flags
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_CAP_PHYS_ADDR``
- 0x00000001
- Userspace has to configure the physical address by calling
:ref:`CEC_ADAP_S_PHYS_ADDR <cec-ioc-adap-g-phys-addr>`. If
this capability isn't set, then setting the physical address is
handled by the kernel whenever the EDID is set (for an HDMI
receiver) or read (for an HDMI transmitter).
- .. row 2
- ``CEC_CAP_LOG_ADDRS``
- 0x00000002
- Userspace has to configure the logical addresses by calling
:ref:`CEC_ADAP_S_LOG_ADDRS <cec-ioc-adap-g-log-addrs>`. If
this capability isn't set, then the kernel will have configured
this.
- .. row 3
- ``CEC_CAP_TRANSMIT``
- 0x00000004
- Userspace can transmit CEC messages by calling
:ref:`CEC_TRANSMIT <cec-ioc-receive>`. This implies that
userspace can be a follower as well, since being able to transmit
messages is a prerequisite of becoming a follower. If this
capability isn't set, then the kernel will handle all CEC
transmits and process all CEC messages it receives.
- .. row 4
- ``CEC_CAP_PASSTHROUGH``
- 0x00000008
- Userspace can use the passthrough mode by calling
:ref:`CEC_S_MODE <cec-ioc-g-mode>`.
- .. row 5
- ``CEC_CAP_RC``
- 0x00000010
- This adapter supports the remote control protocol.
- .. row 6
- ``CEC_CAP_MONITOR_ALL``
- 0x00000020
- The CEC hardware can monitor all messages, not just directed and
broadcast messages.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-ioc-adap-g-log-addrs:
************************************************
ioctl CEC_ADAP_G_LOG_ADDRS, CEC_ADAP_S_LOG_ADDRS
************************************************
*man CEC_ADAP_G_LOG_ADDRS(2)*
CEC_ADAP_S_LOG_ADDRS
Get or set the logical addresses
Synopsis
========
.. c:function:: int ioctl( int fd, int request, struct cec_log_addrs *argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <cec-func-open>`.
``request``
CEC_ADAP_G_LOG_ADDRS, CEC_ADAP_S_LOG_ADDRS
``argp``
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
To query the current CEC logical addresses, applications call the
``CEC_ADAP_G_LOG_ADDRS`` ioctl with a pointer to a
:c:type:`struct cec_log_addrs` structure where the drivers stores
the logical addresses.
To set new logical addresses, applications fill in struct
:c:type:`struct cec_log_addrs` and call the ``CEC_ADAP_S_LOG_ADDRS``
ioctl with a pointer to this struct. The ``CEC_ADAP_S_LOG_ADDRS`` ioctl
is only available if ``CEC_CAP_LOG_ADDRS`` is set (ENOTTY error code is
returned otherwise). This ioctl will block until all requested logical
addresses have been claimed. ``CEC_ADAP_S_LOG_ADDRS`` can only be called
by a file handle in initiator mode (see
:ref:`CEC_S_MODE <cec-ioc-g-mode>`).
.. _cec-log-addrs:
.. flat-table:: struct cec_log_addrs
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u8
- ``log_addr`` [CEC_MAX_LOG_ADDRS]
- The actual logical addresses that were claimed. This is set by the
driver. If no logical address could be claimed, then it is set to
``CEC_LOG_ADDR_INVALID``. If this adapter is Unregistered, then
``log_addr[0]`` is set to 0xf and all others to
``CEC_LOG_ADDR_INVALID``.
- .. row 2
- __u16
- ``log_addr_mask``
- The bitmask of all logical addresses this adapter has claimed. If
this adapter is Unregistered then ``log_addr_mask`` sets bit 15
and clears all other bits. If this adapter is not configured at
all, then ``log_addr_mask`` is set to 0. Set by the driver.
- .. row 3
- __u8
- ``cec_version``
- The CEC version that this adapter shall use. See
:ref:`cec-versions`. Used to implement the
``CEC_MSG_CEC_VERSION`` and ``CEC_MSG_REPORT_FEATURES`` messages.
Note that ``CEC_OP_CEC_VERSION_1_3A`` is not allowed by the CEC
framework.
- .. row 4
- __u8
- ``num_log_addrs``
- Number of logical addresses to set up. Must be ≤
``available_log_addrs`` as returned by
:ref:`CEC_ADAP_G_CAPS <cec-ioc-adap-g-caps>`. All arrays in
this structure are only filled up to index
``available_log_addrs``-1. The remaining array elements will be
ignored. Note that the CEC 2.0 standard allows for a maximum of 2
logical addresses, although some hardware has support for more.
``CEC_MAX_LOG_ADDRS`` is 4. The driver will return the actual
number of logical addresses it could claim, which may be less than
what was requested. If this field is set to 0, then the CEC
adapter shall clear all claimed logical addresses and all other
fields will be ignored.
- .. row 5
- __u32
- ``vendor_id``
- The vendor ID is a 24-bit number that identifies the specific
vendor or entity. Based on this ID vendor specific commands may be
defined. If you do not want a vendor ID then set it to
``CEC_VENDOR_ID_NONE``.
- .. row 6
- __u32
- ``flags``
- Flags. No flags are defined yet, so set this to 0.
- .. row 7
- char
- ``osd_name``\ [15]
- The On-Screen Display name as is returned by the
``CEC_MSG_SET_OSD_NAME`` message.
- .. row 8
- __u8
- ``primary_device_type`` [CEC_MAX_LOG_ADDRS]
- Primary device type for each logical address. See
:ref:`cec-prim-dev-types` for possible types.
- .. row 9
- __u8
- ``log_addr_type`` [CEC_MAX_LOG_ADDRS]
- Logical address types. See :ref:`cec-log-addr-types` for
possible types. The driver will update this with the actual
logical address type that it claimed (e.g. it may have to fallback
to ``CEC_LOG_ADDR_TYPE_UNREGISTERED``).
- .. row 10
- __u8
- ``all_device_types`` [CEC_MAX_LOG_ADDRS]
- CEC 2.0 specific: all device types. See
:ref:`cec-all-dev-types-flags`. Used to implement the
``CEC_MSG_REPORT_FEATURES`` message. This field is ignored if
``cec_version`` < ``CEC_OP_CEC_VERSION_2_0``.
- .. row 11
- __u8
- ``features`` [CEC_MAX_LOG_ADDRS][12]
- Features for each logical address. Used to implement the
``CEC_MSG_REPORT_FEATURES`` message. The 12 bytes include both the
RC Profile and the Device Features. This field is ignored if
``cec_version`` < ``CEC_OP_CEC_VERSION_2_0``.
.. _cec-versions:
.. flat-table:: CEC Versions
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_OP_CEC_VERSION_1_3A``
- 4
- CEC version according to the HDMI 1.3a standard.
- .. row 2
- ``CEC_OP_CEC_VERSION_1_4B``
- 5
- CEC version according to the HDMI 1.4b standard.
- .. row 3
- ``CEC_OP_CEC_VERSION_2_0``
- 6
- CEC version according to the HDMI 2.0 standard.
.. _cec-prim-dev-types:
.. flat-table:: CEC Primary Device Types
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_OP_PRIM_DEVTYPE_TV``
- 0
- Use for a TV.
- .. row 2
- ``CEC_OP_PRIM_DEVTYPE_RECORD``
- 1
- Use for a recording device.
- .. row 3
- ``CEC_OP_PRIM_DEVTYPE_TUNER``
- 3
- Use for a device with a tuner.
- .. row 4
- ``CEC_OP_PRIM_DEVTYPE_PLAYBACK``
- 4
- Use for a playback device.
- .. row 5
- ``CEC_OP_PRIM_DEVTYPE_AUDIOSYSTEM``
- 5
- Use for an audio system (e.g. an audio/video receiver).
- .. row 6
- ``CEC_OP_PRIM_DEVTYPE_SWITCH``
- 6
- Use for a CEC switch.
- .. row 7
- ``CEC_OP_PRIM_DEVTYPE_VIDEOPROC``
- 7
- Use for a video processor device.
.. _cec-log-addr-types:
.. flat-table:: CEC Logical Address Types
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_LOG_ADDR_TYPE_TV``
- 0
- Use for a TV.
- .. row 2
- ``CEC_LOG_ADDR_TYPE_RECORD``
- 1
- Use for a recording device.
- .. row 3
- ``CEC_LOG_ADDR_TYPE_TUNER``
- 2
- Use for a tuner device.
- .. row 4
- ``CEC_LOG_ADDR_TYPE_PLAYBACK``
- 3
- Use for a playback device.
- .. row 5
- ``CEC_LOG_ADDR_TYPE_AUDIOSYSTEM``
- 4
- Use for an audio system device.
- .. row 6
- ``CEC_LOG_ADDR_TYPE_SPECIFIC``
- 5
- Use for a second TV or for a video processor device.
- .. row 7
- ``CEC_LOG_ADDR_TYPE_UNREGISTERED``
- 6
- Use this if you just want to remain unregistered. Used for pure
CEC switches or CDC-only devices (CDC: Capability Discovery and
Control).
.. _cec-all-dev-types-flags:
.. flat-table:: CEC All Device Types Flags
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_OP_ALL_DEVTYPE_TV``
- 0x80
- This supports the TV type.
- .. row 2
- ``CEC_OP_ALL_DEVTYPE_RECORD``
- 0x40
- This supports the Recording type.
- .. row 3
- ``CEC_OP_ALL_DEVTYPE_TUNER``
- 0x20
- This supports the Tuner type.
- .. row 4
- ``CEC_OP_ALL_DEVTYPE_PLAYBACK``
- 0x10
- This supports the Playback type.
- .. row 5
- ``CEC_OP_ALL_DEVTYPE_AUDIOSYSTEM``
- 0x08
- This supports the Audio System type.
- .. row 6
- ``CEC_OP_ALL_DEVTYPE_SWITCH``
- 0x04
- This supports the CEC Switch or Video Processing type.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-ioc-adap-g-phys-addr:
************************************************
ioctl CEC_ADAP_G_PHYS_ADDR, CEC_ADAP_S_PHYS_ADDR
************************************************
*man CEC_ADAP_G_PHYS_ADDR(2)*
CEC_ADAP_S_PHYS_ADDR
Get or set the physical address
Synopsis
========
.. c:function:: int ioctl( int fd, int request, __u16 *argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <cec-func-open>`.
``request``
CEC_ADAP_G_PHYS_ADDR, CEC_ADAP_S_PHYS_ADDR
``argp``
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
To query the current physical address applications call the
``CEC_ADAP_G_PHYS_ADDR`` ioctl with a pointer to an __u16 where the
driver stores the physical address.
To set a new physical address applications store the physical address in
an __u16 and call the ``CEC_ADAP_S_PHYS_ADDR`` ioctl with a pointer to
this integer. ``CEC_ADAP_S_PHYS_ADDR`` is only available if
``CEC_CAP_PHYS_ADDR`` is set (ENOTTY error code will be returned
otherwise). ``CEC_ADAP_S_PHYS_ADDR`` can only be called by a file handle
in initiator mode (see :ref:`CEC_S_MODE <cec-ioc-g-mode>`), if not
EBUSY error code will be returned.
The physical address is a 16-bit number where each group of 4 bits
represent a digit of the physical address a.b.c.d where the most
significant 4 bits represent 'a'. The CEC root device (usually the TV)
has address 0.0.0.0. Every device that is hooked up to an input of the
TV has address a.0.0.0 (where 'a' is ≥ 1), devices hooked up to those in
turn have addresses a.b.0.0, etc. So a topology of up to 5 devices deep
is supported. The physical address a device shall use is stored in the
EDID of the sink.
For example, the EDID for each HDMI input of the TV will have a
different physical address of the form a.0.0.0 that the sources will
read out and use as their physical address.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
.. -*- coding: utf-8; mode: rst -*-
.. _cec-ioc-g-event:
*****************
ioctl CEC_DQEVENT
*****************
*man CEC_DQEVENT(2)*
Dequeue a CEC event
Synopsis
========
.. c:function:: int ioctl( int fd, int request, struct cec_event *argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <cec-func-open>`.
``request``
CEC_DQEVENT
``argp``
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
CEC devices can send asynchronous events. These can be retrieved by
calling the ``CEC_DQEVENT`` ioctl. If the file descriptor is in
non-blocking mode and no event is pending, then it will return -1 and
set errno to the EAGAIN error code.
The internal event queues are per-filehandle and per-event type. If
there is no more room in a queue then the last event is overwritten with
the new one. This means that intermediate results can be thrown away but
that the latest event is always available. This also means that is it
possible to read two successive events that have the same value (e.g.
two CEC_EVENT_STATE_CHANGE events with the same state). In that case
the intermediate state changes were lost but it is guaranteed that the
state did change in between the two events.
.. _cec-event-state-change:
.. flat-table:: struct cec_event_state_change
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u16
- ``phys_addr``
- The current physical address.
- .. row 2
- __u16
- ``log_addr_mask``
- The current set of claimed logical addresses.
.. _cec-event-lost-msgs:
.. flat-table:: struct cec_event_lost_msgs
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u32
- ``lost_msgs``
- Set to the number of lost messages since the filehandle was opened
or since the last time this event was dequeued for this
filehandle. The messages lost are the oldest messages. So when a
new message arrives and there is no more room, then the oldest
message is discarded to make room for the new one. The internal
size of the message queue guarantees that all messages received in
the last two seconds will be stored. Since messages should be
replied to within a second according to the CEC specification,
this is more than enough.
.. _cec-event:
.. flat-table:: struct cec_event
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2 1
- .. row 1
- __u64
- ``ts``
- Timestamp of the event in ns.
-
- .. row 2
- __u32
- ``event``
- The CEC event type, see :ref:`cec-events`.
-
- .. row 3
- __u32
- ``flags``
- Event flags, see :ref:`cec-event-flags`.
-
- .. row 4
- union
- (anonymous)
-
-
- .. row 5
-
- struct cec_event_state_change
- ``state_change``
- The new adapter state as sent by the ``CEC_EVENT_STATE_CHANGE``
event.
- .. row 6
-
- struct cec_event_lost_msgs
- ``lost_msgs``
- The number of lost messages as sent by the ``CEC_EVENT_LOST_MSGS``
event.
.. _cec-events:
.. flat-table:: CEC Events Types
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_EVENT_STATE_CHANGE``
- 1
- Generated when the CEC Adapter's state changes. When open() is
called an initial event will be generated for that filehandle with
the CEC Adapter's state at that time.
- .. row 2
- ``CEC_EVENT_LOST_MSGS``
- 2
- Generated if one or more CEC messages were lost because the
application didn't dequeue CEC messages fast enough.
.. _cec-event-flags:
.. flat-table:: CEC Event Flags
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_EVENT_FL_INITIAL_VALUE``
- 1
- Set for the initial events that are generated when the device is
opened. See the table above for which events do this. This allows
applications to learn the initial state of the CEC adapter at
open() time.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
This diff is collapsed.
.. -*- coding: utf-8; mode: rst -*-
.. _cec-ioc-receive:
*******************************
ioctl CEC_RECEIVE, CEC_TRANSMIT
*******************************
*man CEC_RECEIVE(2)*
CEC_TRANSMIT
Receive or transmit a CEC message
Synopsis
========
.. c:function:: int ioctl( int fd, int request, struct cec_msg *argp )
Arguments
=========
``fd``
File descriptor returned by :ref:`open() <cec-func-open>`.
``request``
CEC_RECEIVE, CEC_TRANSMIT
``argp``
Description
===========
Note: this documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
To receive a CEC message the application has to fill in the
:c:type:`struct cec_msg` structure and pass it to the ``CEC_RECEIVE``
ioctl. ``CEC_RECEIVE`` is only available if ``CEC_CAP_RECEIVE`` is set.
If the file descriptor is in non-blocking mode and there are no received
messages pending, then it will return -1 and set errno to the EAGAIN
error code. If the file descriptor is in blocking mode and ``timeout``
is non-zero and no message arrived within ``timeout`` milliseconds, then
it will return -1 and set errno to the ETIMEDOUT error code.
To send a CEC message the application has to fill in the
:c:type:`struct cec_msg` structure and pass it to the
``CEC_TRANSMIT`` ioctl. ``CEC_TRANSMIT`` is only available if
``CEC_CAP_TRANSMIT`` is set. If there is no more room in the transmit
queue, then it will return -1 and set errno to the EBUSY error code.
.. _cec-msg:
.. flat-table:: struct cec_msg
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
- .. row 1
- __u64
- ``ts``
- Timestamp of when the message was transmitted in ns in the case of
``CEC_TRANSMIT`` with ``reply`` set to 0, or the timestamp of the
received message in all other cases.
- .. row 2
- __u32
- ``len``
- The length of the message. For ``CEC_TRANSMIT`` this is filled in
by the application. The driver will fill this in for
``CEC_RECEIVE`` and for ``CEC_TRANSMIT`` it will be filled in with
the length of the reply message if ``reply`` was set.
- .. row 3
- __u32
- ``timeout``
- The timeout in milliseconds. This is the time the device will wait
for a message to be received before timing out. If it is set to 0,
then it will wait indefinitely when it is called by
``CEC_RECEIVE``. If it is 0 and it is called by ``CEC_TRANSMIT``,
then it will be replaced by 1000 if the ``reply`` is non-zero or
ignored if ``reply`` is 0.
- .. row 4
- __u32
- ``sequence``
- The sequence number is automatically assigned by the CEC framework
for all transmitted messages. It can be later used by the
framework to generate an event if a reply for a message was
requested and the message was transmitted in a non-blocking mode.
- .. row 5
- __u32
- ``flags``
- Flags. No flags are defined yet, so set this to 0.
- .. row 6
- __u8
- ``rx_status``
- The status bits of the received message. See
:ref:`cec-rx-status` for the possible status values. It is 0 if
this message was transmitted, not received, unless this is the
reply to a transmitted message. In that case both ``rx_status``
and ``tx_status`` are set.
- .. row 7
- __u8
- ``tx_status``
- The status bits of the transmitted message. See
:ref:`cec-tx-status` for the possible status values. It is 0 if
this messages was received, not transmitted.
- .. row 8
- __u8
- ``msg``\ [16]
- The message payload. For ``CEC_TRANSMIT`` this is filled in by the
application. The driver will fill this in for ``CEC_RECEIVE`` and
for ``CEC_TRANSMIT`` it will be filled in with the payload of the
reply message if ``reply`` was set.
- .. row 9
- __u8
- ``reply``
- Wait until this message is replied. If ``reply`` is 0 and the
``timeout`` is 0, then don't wait for a reply but return after
transmitting the message. If there was an error as indicated by a
non-zero ``tx_status`` field, then ``reply`` and ``timeout`` are
both set to 0 by the driver. Ignored by ``CEC_RECEIVE``. The case
where ``reply`` is 0 (this is the opcode for the Feature Abort
message) and ``timeout`` is non-zero is specifically allowed to
send a message and wait up to ``timeout`` milliseconds for a
Feature Abort reply. In this case ``rx_status`` will either be set
to ``CEC_RX_STATUS_TIMEOUT`` or ``CEC_RX_STATUS_FEATURE_ABORT``.
- .. row 10
- __u8
- ``tx_arb_lost_cnt``
- A counter of the number of transmit attempts that resulted in the
Arbitration Lost error. This is only set if the hardware supports
this, otherwise it is always 0. This counter is only valid if the
``CEC_TX_STATUS_ARB_LOST`` status bit is set.
- .. row 11
- __u8
- ``tx_nack_cnt``
- A counter of the number of transmit attempts that resulted in the
Not Acknowledged error. This is only set if the hardware supports
this, otherwise it is always 0. This counter is only valid if the
``CEC_TX_STATUS_NACK`` status bit is set.
- .. row 12
- __u8
- ``tx_low_drive_cnt``
- A counter of the number of transmit attempts that resulted in the
Arbitration Lost error. This is only set if the hardware supports
this, otherwise it is always 0. This counter is only valid if the
``CEC_TX_STATUS_LOW_DRIVE`` status bit is set.
- .. row 13
- __u8
- ``tx_error_cnt``
- A counter of the number of transmit errors other than Arbitration
Lost or Not Acknowledged. This is only set if the hardware
supports this, otherwise it is always 0. This counter is only
valid if the ``CEC_TX_STATUS_ERROR`` status bit is set.
.. _cec-tx-status:
.. flat-table:: CEC Transmit Status
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_TX_STATUS_OK``
- 0x01
- The message was transmitted successfully. This is mutually
exclusive with ``CEC_TX_STATUS_MAX_RETRIES``. Other bits can still
be set if earlier attempts met with failure before the transmit
was eventually successful.
- .. row 2
- ``CEC_TX_STATUS_ARB_LOST``
- 0x02
- CEC line arbitration was lost.
- .. row 3
- ``CEC_TX_STATUS_NACK``
- 0x04
- Message was not acknowledged.
- .. row 4
- ``CEC_TX_STATUS_LOW_DRIVE``
- 0x08
- Low drive was detected on the CEC bus. This indicates that a
follower detected an error on the bus and requests a
retransmission.
- .. row 5
- ``CEC_TX_STATUS_ERROR``
- 0x10
- Some error occurred. This is used for any errors that do not fit
the previous two, either because the hardware could not tell which
error occurred, or because the hardware tested for other
conditions besides those two.
- .. row 6
- ``CEC_TX_STATUS_MAX_RETRIES``
- 0x20
- The transmit failed after one or more retries. This status bit is
mutually exclusive with ``CEC_TX_STATUS_OK``. Other bits can still
be set to explain which failures were seen.
.. _cec-rx-status:
.. flat-table:: CEC Receive Status
:header-rows: 0
:stub-columns: 0
:widths: 3 1 4
- .. row 1
- ``CEC_RX_STATUS_OK``
- 0x01
- The message was received successfully.
- .. row 2
- ``CEC_RX_STATUS_TIMEOUT``
- 0x02
- The reply to an earlier transmitted message timed out.
- .. row 3
- ``CEC_RX_STATUS_FEATURE_ABORT``
- 0x04
- The message was received successfully but the reply was
``CEC_MSG_FEATURE_ABORT``. This status is only set if this message
was the reply to an earlier transmitted message.
Return Value
============
On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
.. ------------------------------------------------------------------------------
.. This file was automatically converted from DocBook-XML with the dbxml
.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
.. from the linux kernel, refer to:
..
.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
.. ------------------------------------------------------------------------------
......@@ -349,6 +349,16 @@ HDMI
:author: HDMI Licensing LLC (http://www.hdmi.org)
.. _hdmi2:
HDMI2
=====
:title: High-Definition Multimedia Interface
:subtitle: Specification Version 2.0
:author: HDMI Licensing LLC (http://www.hdmi.org)
.. _dp:
DP
......
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