1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: CEC
3
4.. _CEC_ADAP_PHYS_ADDR:
5.. _CEC_ADAP_G_PHYS_ADDR:
6.. _CEC_ADAP_S_PHYS_ADDR:
7
8****************************************************
9ioctls CEC_ADAP_G_PHYS_ADDR and CEC_ADAP_S_PHYS_ADDR
10****************************************************
11
12Name
13====
14
15CEC_ADAP_G_PHYS_ADDR, CEC_ADAP_S_PHYS_ADDR - Get or set the physical address
16
17Synopsis
18========
19
20.. c:macro:: CEC_ADAP_G_PHYS_ADDR
21
22``int ioctl(int fd, CEC_ADAP_G_PHYS_ADDR, __u16 *argp)``
23
24.. c:macro:: CEC_ADAP_S_PHYS_ADDR
25
26``int ioctl(int fd, CEC_ADAP_S_PHYS_ADDR, __u16 *argp)``
27
28Arguments
29=========
30
31``fd``
32    File descriptor returned by :c:func:`open()`.
33
34``argp``
35    Pointer to the CEC address.
36
37Description
38===========
39
40To query the current physical address applications call
41:ref:`ioctl CEC_ADAP_G_PHYS_ADDR <CEC_ADAP_G_PHYS_ADDR>` with a pointer to a __u16 where the
42driver stores the physical address.
43
44To set a new physical address applications store the physical address in
45a __u16 and call :ref:`ioctl CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` with a pointer to
46this integer. The :ref:`ioctl CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` is only available if
47``CEC_CAP_PHYS_ADDR`` is set (the ``ENOTTY`` error code will be returned
48otherwise). The :ref:`ioctl CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` can only be called
49by a file descriptor in initiator mode (see :ref:`CEC_S_MODE`), if not
50the ``EBUSY`` error code will be returned.
51
52To clear an existing physical address use ``CEC_PHYS_ADDR_INVALID``.
53The adapter will go to the unconfigured state.
54
55If logical address types have been defined (see :ref:`ioctl CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`),
56then this ioctl will block until all
57requested logical addresses have been claimed. If the file descriptor is in non-blocking mode
58then it will not wait for the logical addresses to be claimed, instead it just returns 0.
59
60A :ref:`CEC_EVENT_STATE_CHANGE <CEC-EVENT-STATE-CHANGE>` event is sent when the physical address
61changes.
62
63The physical address is a 16-bit number where each group of 4 bits
64represent a digit of the physical address a.b.c.d where the most
65significant 4 bits represent 'a'. The CEC root device (usually the TV)
66has address 0.0.0.0. Every device that is hooked up to an input of the
67TV has address a.0.0.0 (where 'a' is ≥ 1), devices hooked up to those in
68turn have addresses a.b.0.0, etc. So a topology of up to 5 devices deep
69is supported. The physical address a device shall use is stored in the
70EDID of the sink.
71
72For example, the EDID for each HDMI input of the TV will have a
73different physical address of the form a.0.0.0 that the sources will
74read out and use as their physical address.
75
76Return Value
77============
78
79On success 0 is returned, on error -1 and the ``errno`` variable is set
80appropriately. The generic error codes are described at the
81:ref:`Generic Error Codes <gen-errors>` chapter.
82
83The :ref:`ioctl CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` can return the following
84error codes:
85
86ENOTTY
87    The ``CEC_CAP_PHYS_ADDR`` capability wasn't set, so this ioctl is not supported.
88
89EBUSY
90    Another filehandle is in exclusive follower or initiator mode, or the filehandle
91    is in mode ``CEC_MODE_NO_INITIATOR``.
92
93EINVAL
94    The physical address is malformed.
95