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1 | .. -*- coding: utf-8; mode: rst -*- |
2 | ||
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3 | .. _CEC_MODE: |
4 | .. _CEC_G_MODE: | |
5 | .. _CEC_S_MODE: | |
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7 | ******************************** |
8 | ioctls CEC_G_MODE and CEC_S_MODE | |
9 | ******************************** | |
e2460b1d | 10 | |
21c62694 | 11 | CEC_G_MODE, CEC_S_MODE - Get or set exclusive use of the CEC adapter |
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12 | |
13 | Synopsis | |
14 | ======== | |
15 | ||
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16 | .. c:function:: int ioctl( int fd, CEC_G_MODE, __u32 *argp ) |
17 | :name: CEC_G_MODE | |
18 | ||
19 | .. c:function:: int ioctl( int fd, CEC_S_MODE, __u32 *argp ) | |
20 | :name: CEC_S_MODE | |
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21 | |
22 | Arguments | |
23 | ========= | |
24 | ||
25 | ``fd`` | |
99547836 | 26 | File descriptor returned by :c:func:`open() <cec-open>`. |
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27 | |
28 | ``argp`` | |
99547836 | 29 | Pointer to CEC mode. |
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30 | |
31 | Description | |
32 | =========== | |
33 | ||
1267c60a | 34 | By default any filehandle can use :ref:`CEC_TRANSMIT`, but in order to prevent |
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35 | applications from stepping on each others toes it must be possible to |
36 | obtain exclusive access to the CEC adapter. This ioctl sets the | |
37 | filehandle to initiator and/or follower mode which can be exclusive | |
38 | depending on the chosen mode. The initiator is the filehandle that is | |
39 | used to initiate messages, i.e. it commands other CEC devices. The | |
40 | follower is the filehandle that receives messages sent to the CEC | |
41 | adapter and processes them. The same filehandle can be both initiator | |
42 | and follower, or this role can be taken by two different filehandles. | |
43 | ||
44 | When a CEC message is received, then the CEC framework will decide how | |
45 | it will be processed. If the message is a reply to an earlier | |
46 | transmitted message, then the reply is sent back to the filehandle that | |
47 | is waiting for it. In addition the CEC framework will process it. | |
48 | ||
49 | If the message is not a reply, then the CEC framework will process it | |
50 | first. If there is no follower, then the message is just discarded and a | |
51 | feature abort is sent back to the initiator if the framework couldn't | |
52 | process it. If there is a follower, then the message is passed on to the | |
1267c60a | 53 | follower who will use :ref:`ioctl CEC_RECEIVE <CEC_RECEIVE>` to dequeue |
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54 | the new message. The framework expects the follower to make the right |
55 | decisions. | |
56 | ||
57 | The CEC framework will process core messages unless requested otherwise | |
58 | by the follower. The follower can enable the passthrough mode. In that | |
59 | case, the CEC framework will pass on most core messages without | |
60 | processing them and the follower will have to implement those messages. | |
61 | There are some messages that the core will always process, regardless of | |
62 | the passthrough mode. See :ref:`cec-core-processing` for details. | |
63 | ||
64 | If there is no initiator, then any CEC filehandle can use | |
1267c60a | 65 | :ref:`ioctl CEC_TRANSMIT <CEC_TRANSMIT>`. If there is an exclusive |
e2460b1d | 66 | initiator then only that initiator can call |
21c62694 | 67 | :ref:`CEC_TRANSMIT`. The follower can of course |
1267c60a | 68 | always call :ref:`ioctl CEC_TRANSMIT <CEC_TRANSMIT>`. |
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69 | |
70 | Available initiator modes are: | |
71 | ||
fa92b04d | 72 | .. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{11.0cm}| |
e2460b1d | 73 | |
96f69e0e | 74 | .. _cec-mode-initiator_e: |
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75 | |
76 | .. flat-table:: Initiator Modes | |
77 | :header-rows: 0 | |
78 | :stub-columns: 0 | |
b2a58436 | 79 | :widths: 3 1 16 |
e2460b1d | 80 | |
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81 | * .. _`CEC-MODE-NO-INITIATOR`: |
82 | ||
83 | - ``CEC_MODE_NO_INITIATOR`` | |
84 | - 0x0 | |
85 | - This is not an initiator, i.e. it cannot transmit CEC messages or | |
86 | make any other changes to the CEC adapter. | |
87 | * .. _`CEC-MODE-INITIATOR`: | |
88 | ||
89 | - ``CEC_MODE_INITIATOR`` | |
90 | - 0x1 | |
91 | - This is an initiator (the default when the device is opened) and | |
92 | it can transmit CEC messages and make changes to the CEC adapter, | |
93 | unless there is an exclusive initiator. | |
94 | * .. _`CEC-MODE-EXCL-INITIATOR`: | |
95 | ||
96 | - ``CEC_MODE_EXCL_INITIATOR`` | |
97 | - 0x2 | |
98 | - This is an exclusive initiator and this file descriptor is the | |
99 | only one that can transmit CEC messages and make changes to the | |
100 | CEC adapter. If someone else is already the exclusive initiator | |
101 | then an attempt to become one will return the ``EBUSY`` error code | |
102 | error. | |
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103 | |
104 | ||
105 | Available follower modes are: | |
106 | ||
fa92b04d | 107 | .. tabularcolumns:: |p{6.6cm}|p{0.9cm}|p{10.0cm}| |
e2460b1d | 108 | |
96f69e0e | 109 | .. _cec-mode-follower_e: |
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110 | |
111 | .. flat-table:: Follower Modes | |
112 | :header-rows: 0 | |
113 | :stub-columns: 0 | |
b2a58436 | 114 | :widths: 3 1 16 |
e2460b1d | 115 | |
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116 | * .. _`CEC-MODE-NO-FOLLOWER`: |
117 | ||
118 | - ``CEC_MODE_NO_FOLLOWER`` | |
119 | - 0x00 | |
120 | - This is not a follower (the default when the device is opened). | |
121 | * .. _`CEC-MODE-FOLLOWER`: | |
122 | ||
123 | - ``CEC_MODE_FOLLOWER`` | |
124 | - 0x10 | |
125 | - This is a follower and it will receive CEC messages unless there | |
126 | is an exclusive follower. You cannot become a follower if | |
127 | :ref:`CEC_CAP_TRANSMIT <CEC-CAP-TRANSMIT>` is not set or if :ref:`CEC_MODE_NO_INITIATOR <CEC-MODE-NO-INITIATOR>` | |
128 | was specified, the ``EINVAL`` error code is returned in that case. | |
129 | * .. _`CEC-MODE-EXCL-FOLLOWER`: | |
130 | ||
131 | - ``CEC_MODE_EXCL_FOLLOWER`` | |
132 | - 0x20 | |
133 | - This is an exclusive follower and only this file descriptor will | |
134 | receive CEC messages for processing. If someone else is already | |
135 | the exclusive follower then an attempt to become one will return | |
136 | the ``EBUSY`` error code. You cannot become a follower if | |
137 | :ref:`CEC_CAP_TRANSMIT <CEC-CAP-TRANSMIT>` is not set or if :ref:`CEC_MODE_NO_INITIATOR <CEC-MODE-NO-INITIATOR>` | |
138 | was specified, the ``EINVAL`` error code is returned in that case. | |
139 | * .. _`CEC-MODE-EXCL-FOLLOWER-PASSTHRU`: | |
140 | ||
141 | - ``CEC_MODE_EXCL_FOLLOWER_PASSTHRU`` | |
142 | - 0x30 | |
143 | - This is an exclusive follower and only this file descriptor will | |
144 | receive CEC messages for processing. In addition it will put the | |
145 | CEC device into passthrough mode, allowing the exclusive follower | |
146 | to handle most core messages instead of relying on the CEC | |
147 | framework for that. If someone else is already the exclusive | |
148 | follower then an attempt to become one will return the ``EBUSY`` error | |
149 | code. You cannot become a follower if :ref:`CEC_CAP_TRANSMIT <CEC-CAP-TRANSMIT>` | |
150 | is not set or if :ref:`CEC_MODE_NO_INITIATOR <CEC-MODE-NO-INITIATOR>` was specified, | |
151 | the ``EINVAL`` error code is returned in that case. | |
152 | * .. _`CEC-MODE-MONITOR`: | |
153 | ||
154 | - ``CEC_MODE_MONITOR`` | |
155 | - 0xe0 | |
156 | - Put the file descriptor into monitor mode. Can only be used in | |
157 | combination with :ref:`CEC_MODE_NO_INITIATOR <CEC-MODE-NO-INITIATOR>`, otherwise EINVAL error | |
158 | code will be returned. In monitor mode all messages this CEC | |
159 | device transmits and all messages it receives (both broadcast | |
160 | messages and directed messages for one its logical addresses) will | |
161 | be reported. This is very useful for debugging. This is only | |
162 | allowed if the process has the ``CAP_NET_ADMIN`` capability. If | |
163 | that is not set, then the ``EPERM`` error code is returned. | |
164 | * .. _`CEC-MODE-MONITOR-ALL`: | |
165 | ||
166 | - ``CEC_MODE_MONITOR_ALL`` | |
167 | - 0xf0 | |
168 | - Put the file descriptor into 'monitor all' mode. Can only be used | |
169 | in combination with :ref:`CEC_MODE_NO_INITIATOR <CEC-MODE-NO-INITIATOR>`, otherwise | |
170 | the ``EINVAL`` error code will be returned. In 'monitor all' mode all messages | |
171 | this CEC device transmits and all messages it receives, including | |
172 | directed messages for other CEC devices will be reported. This is | |
173 | very useful for debugging, but not all devices support this. This | |
174 | mode requires that the :ref:`CEC_CAP_MONITOR_ALL <CEC-CAP-MONITOR-ALL>` capability is set, | |
175 | otherwise the ``EINVAL`` error code is returned. This is only allowed if | |
176 | the process has the ``CAP_NET_ADMIN`` capability. If that is not | |
177 | set, then the ``EPERM`` error code is returned. | |
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178 | |
179 | ||
180 | Core message processing details: | |
181 | ||
fa92b04d | 182 | .. tabularcolumns:: |p{6.6cm}|p{10.9cm}| |
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183 | |
184 | .. _cec-core-processing: | |
185 | ||
186 | .. flat-table:: Core Message Processing | |
187 | :header-rows: 0 | |
188 | :stub-columns: 0 | |
b2a58436 | 189 | :widths: 1 8 |
e2460b1d | 190 | |
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191 | * .. _`CEC-MSG-GET-CEC-VERSION`: |
192 | ||
193 | - ``CEC_MSG_GET_CEC_VERSION`` | |
194 | - When in passthrough mode this message has to be handled by | |
195 | userspace, otherwise the core will return the CEC version that was | |
196 | set with :ref:`ioctl CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`. | |
197 | * .. _`CEC-MSG-GIVE-DEVICE-VENDOR-ID`: | |
198 | ||
199 | - ``CEC_MSG_GIVE_DEVICE_VENDOR_ID`` | |
200 | - When in passthrough mode this message has to be handled by | |
201 | userspace, otherwise the core will return the vendor ID that was | |
202 | set with :ref:`ioctl CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`. | |
203 | * .. _`CEC-MSG-ABORT`: | |
204 | ||
205 | - ``CEC_MSG_ABORT`` | |
206 | - When in passthrough mode this message has to be handled by | |
207 | userspace, otherwise the core will return a feature refused | |
208 | message as per the specification. | |
209 | * .. _`CEC-MSG-GIVE-PHYSICAL-ADDR`: | |
210 | ||
211 | - ``CEC_MSG_GIVE_PHYSICAL_ADDR`` | |
212 | - When in passthrough mode this message has to be handled by | |
213 | userspace, otherwise the core will report the current physical | |
214 | address. | |
215 | * .. _`CEC-MSG-GIVE-OSD-NAME`: | |
216 | ||
217 | - ``CEC_MSG_GIVE_OSD_NAME`` | |
218 | - When in passthrough mode this message has to be handled by | |
219 | userspace, otherwise the core will report the current OSD name as | |
220 | was set with :ref:`ioctl CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`. | |
221 | * .. _`CEC-MSG-GIVE-FEATURES`: | |
222 | ||
223 | - ``CEC_MSG_GIVE_FEATURES`` | |
224 | - When in passthrough mode this message has to be handled by | |
225 | userspace, otherwise the core will report the current features as | |
226 | was set with :ref:`ioctl CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>` | |
227 | or the message is ignored if the CEC version was older than 2.0. | |
228 | * .. _`CEC-MSG-USER-CONTROL-PRESSED`: | |
229 | ||
230 | - ``CEC_MSG_USER_CONTROL_PRESSED`` | |
231 | - If :ref:`CEC_CAP_RC <CEC-CAP-RC>` is set, then generate a remote control key | |
232 | press. This message is always passed on to userspace. | |
233 | * .. _`CEC-MSG-USER-CONTROL-RELEASED`: | |
234 | ||
235 | - ``CEC_MSG_USER_CONTROL_RELEASED`` | |
236 | - If :ref:`CEC_CAP_RC <CEC-CAP-RC>` is set, then generate a remote control key | |
237 | release. This message is always passed on to userspace. | |
238 | * .. _`CEC-MSG-REPORT-PHYSICAL-ADDR`: | |
239 | ||
240 | - ``CEC_MSG_REPORT_PHYSICAL_ADDR`` | |
241 | - The CEC framework will make note of the reported physical address | |
242 | and then just pass the message on to userspace. | |
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243 | |
244 | ||
245 | ||
246 | Return Value | |
247 | ============ | |
248 | ||
249 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
250 | appropriately. The generic error codes are described at the | |
251 | :ref:`Generic Error Codes <gen-errors>` chapter. |