1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 .. c:namespace:: CEC 2 .. c:namespace:: CEC
3 3
4 .. _CEC_DQEVENT: 4 .. _CEC_DQEVENT:
5 5
6 ***************** 6 *****************
7 ioctl CEC_DQEVENT 7 ioctl CEC_DQEVENT
8 ***************** 8 *****************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 CEC_DQEVENT - Dequeue a CEC event 13 CEC_DQEVENT - Dequeue a CEC event
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: CEC_DQEVENT 18 .. c:macro:: CEC_DQEVENT
19 19
20 ``int ioctl(int fd, CEC_DQEVENT, struct cec_ev 20 ``int ioctl(int fd, CEC_DQEVENT, struct cec_event *argp)``
21 21
22 Arguments 22 Arguments
23 ========= 23 =========
24 24
25 ``fd`` 25 ``fd``
26 File descriptor returned by :c:func:`open( 26 File descriptor returned by :c:func:`open()`.
27 27
28 ``argp`` 28 ``argp``
29 29
30 Description 30 Description
31 =========== 31 ===========
32 32
33 CEC devices can send asynchronous events. Thes 33 CEC devices can send asynchronous events. These can be retrieved by
34 calling :c:func:`CEC_DQEVENT`. If the file des 34 calling :c:func:`CEC_DQEVENT`. If the file descriptor is in
35 non-blocking mode and no event is pending, the 35 non-blocking mode and no event is pending, then it will return -1 and
36 set errno to the ``EAGAIN`` error code. 36 set errno to the ``EAGAIN`` error code.
37 37
38 The internal event queues are per-filehandle a 38 The internal event queues are per-filehandle and per-event type. If
39 there is no more room in a queue then the last 39 there is no more room in a queue then the last event is overwritten with
40 the new one. This means that intermediate resu 40 the new one. This means that intermediate results can be thrown away but
41 that the latest event is always available. Thi 41 that the latest event is always available. This also means that is it
42 possible to read two successive events that ha 42 possible to read two successive events that have the same value (e.g.
43 two :ref:`CEC_EVENT_STATE_CHANGE <CEC-EVENT-ST 43 two :ref:`CEC_EVENT_STATE_CHANGE <CEC-EVENT-STATE-CHANGE>` events with
44 the same state). In that case the intermediate 44 the same state). In that case the intermediate state changes were lost but
45 it is guaranteed that the state did change in 45 it is guaranteed that the state did change in between the two events.
46 46
47 .. tabularcolumns:: |p{1.2cm}|p{2.9cm}|p{13.2c 47 .. tabularcolumns:: |p{1.2cm}|p{2.9cm}|p{13.2cm}|
48 48
49 .. c:type:: cec_event_state_change 49 .. c:type:: cec_event_state_change
50 50
51 .. flat-table:: struct cec_event_state_change 51 .. flat-table:: struct cec_event_state_change
52 :header-rows: 0 52 :header-rows: 0
53 :stub-columns: 0 53 :stub-columns: 0
54 :widths: 1 1 8 54 :widths: 1 1 8
55 55
56 * - __u16 56 * - __u16
57 - ``phys_addr`` 57 - ``phys_addr``
58 - The current physical address. This is 58 - The current physical address. This is ``CEC_PHYS_ADDR_INVALID`` if no
59 valid physical address is set. 59 valid physical address is set.
60 * - __u16 60 * - __u16
61 - ``log_addr_mask`` 61 - ``log_addr_mask``
62 - The current set of claimed logical add 62 - The current set of claimed logical addresses. This is 0 if no logical
63 addresses are claimed or if ``phys_add 63 addresses are claimed or if ``phys_addr`` is ``CEC_PHYS_ADDR_INVALID``.
64 If bit 15 is set (``1 << CEC_LOG_ADDR_ 64 If bit 15 is set (``1 << CEC_LOG_ADDR_UNREGISTERED``) then this device
65 has the unregistered logical address. 65 has the unregistered logical address. In that case all other bits are 0.
66 * - __u16 66 * - __u16
67 - ``have_conn_info`` 67 - ``have_conn_info``
68 - If non-zero, then HDMI connector infor 68 - If non-zero, then HDMI connector information is available.
69 This field is only valid if ``CEC_CAP_ 69 This field is only valid if ``CEC_CAP_CONNECTOR_INFO`` is set. If that
70 capability is set and ``have_conn_info 70 capability is set and ``have_conn_info`` is zero, then that indicates
71 that the HDMI connector device is not 71 that the HDMI connector device is not instantiated, either because
72 the HDMI driver is still configuring t 72 the HDMI driver is still configuring the device or because the HDMI
73 device was unbound. 73 device was unbound.
74 74
75 .. c:type:: cec_event_lost_msgs 75 .. c:type:: cec_event_lost_msgs
76 76
77 .. tabularcolumns:: |p{1.0cm}|p{2.0cm}|p{14.3c 77 .. tabularcolumns:: |p{1.0cm}|p{2.0cm}|p{14.3cm}|
78 78
79 .. flat-table:: struct cec_event_lost_msgs 79 .. flat-table:: struct cec_event_lost_msgs
80 :header-rows: 0 80 :header-rows: 0
81 :stub-columns: 0 81 :stub-columns: 0
82 :widths: 1 1 16 82 :widths: 1 1 16
83 83
84 * - __u32 84 * - __u32
85 - ``lost_msgs`` 85 - ``lost_msgs``
86 - Set to the number of lost messages sin 86 - Set to the number of lost messages since the filehandle was opened
87 or since the last time this event was 87 or since the last time this event was dequeued for this
88 filehandle. The messages lost are the 88 filehandle. The messages lost are the oldest messages. So when a
89 new message arrives and there is no mo 89 new message arrives and there is no more room, then the oldest
90 message is discarded to make room for 90 message is discarded to make room for the new one. The internal
91 size of the message queue guarantees t 91 size of the message queue guarantees that all messages received in
92 the last two seconds will be stored. S 92 the last two seconds will be stored. Since messages should be
93 replied to within a second according t 93 replied to within a second according to the CEC specification,
94 this is more than enough. 94 this is more than enough.
95 95
96 .. tabularcolumns:: |p{1.0cm}|p{4.4cm}|p{2.5cm 96 .. tabularcolumns:: |p{1.0cm}|p{4.4cm}|p{2.5cm}|p{9.2cm}|
97 97
98 .. c:type:: cec_event 98 .. c:type:: cec_event
99 99
100 .. flat-table:: struct cec_event 100 .. flat-table:: struct cec_event
101 :header-rows: 0 101 :header-rows: 0
102 :stub-columns: 0 102 :stub-columns: 0
103 :widths: 1 1 8 103 :widths: 1 1 8
104 104
105 * - __u64 105 * - __u64
106 - ``ts`` 106 - ``ts``
107 - Timestamp of the event in ns. 107 - Timestamp of the event in ns.
108 108
109 The timestamp has been taken from the 109 The timestamp has been taken from the ``CLOCK_MONOTONIC`` clock.
110 110
111 To access the same clock from userspac 111 To access the same clock from userspace use :c:func:`clock_gettime`.
112 * - __u32 112 * - __u32
113 - ``event`` 113 - ``event``
114 - The CEC event type, see :ref:`cec-even 114 - The CEC event type, see :ref:`cec-events`.
115 * - __u32 115 * - __u32
116 - ``flags`` 116 - ``flags``
117 - Event flags, see :ref:`cec-event-flags 117 - Event flags, see :ref:`cec-event-flags`.
118 * - union { 118 * - union {
119 - (anonymous) 119 - (anonymous)
120 * - struct cec_event_state_change 120 * - struct cec_event_state_change
121 - ``state_change`` 121 - ``state_change``
122 - The new adapter state as sent by the : 122 - The new adapter state as sent by the :ref:`CEC_EVENT_STATE_CHANGE <CEC-EVENT-STATE-CHANGE>`
123 event. 123 event.
124 * - struct cec_event_lost_msgs 124 * - struct cec_event_lost_msgs
125 - ``lost_msgs`` 125 - ``lost_msgs``
126 - The number of lost messages as sent by 126 - The number of lost messages as sent by the :ref:`CEC_EVENT_LOST_MSGS <CEC-EVENT-LOST-MSGS>`
127 event. 127 event.
128 * - } 128 * - }
129 - 129 -
130 130
131 .. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{10.8c 131 .. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{10.8cm}|
132 132
133 .. _cec-events: 133 .. _cec-events:
134 134
135 .. flat-table:: CEC Events Types 135 .. flat-table:: CEC Events Types
136 :header-rows: 0 136 :header-rows: 0
137 :stub-columns: 0 137 :stub-columns: 0
138 :widths: 3 1 16 138 :widths: 3 1 16
139 139
140 * .. _`CEC-EVENT-STATE-CHANGE`: 140 * .. _`CEC-EVENT-STATE-CHANGE`:
141 141
142 - ``CEC_EVENT_STATE_CHANGE`` 142 - ``CEC_EVENT_STATE_CHANGE``
143 - 1 143 - 1
144 - Generated when the CEC Adapter's state 144 - Generated when the CEC Adapter's state changes. When open() is
145 called an initial event will be genera 145 called an initial event will be generated for that filehandle with
146 the CEC Adapter's state at that time. 146 the CEC Adapter's state at that time.
147 * .. _`CEC-EVENT-LOST-MSGS`: 147 * .. _`CEC-EVENT-LOST-MSGS`:
148 148
149 - ``CEC_EVENT_LOST_MSGS`` 149 - ``CEC_EVENT_LOST_MSGS``
150 - 2 150 - 2
151 - Generated if one or more CEC messages 151 - Generated if one or more CEC messages were lost because the
152 application didn't dequeue CEC message 152 application didn't dequeue CEC messages fast enough.
153 * .. _`CEC-EVENT-PIN-CEC-LOW`: 153 * .. _`CEC-EVENT-PIN-CEC-LOW`:
154 154
155 - ``CEC_EVENT_PIN_CEC_LOW`` 155 - ``CEC_EVENT_PIN_CEC_LOW``
156 - 3 156 - 3
157 - Generated if the CEC pin goes from a h 157 - Generated if the CEC pin goes from a high voltage to a low voltage.
158 Only applies to adapters that have the 158 Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
159 capability set. 159 capability set.
160 * .. _`CEC-EVENT-PIN-CEC-HIGH`: 160 * .. _`CEC-EVENT-PIN-CEC-HIGH`:
161 161
162 - ``CEC_EVENT_PIN_CEC_HIGH`` 162 - ``CEC_EVENT_PIN_CEC_HIGH``
163 - 4 163 - 4
164 - Generated if the CEC pin goes from a l 164 - Generated if the CEC pin goes from a low voltage to a high voltage.
165 Only applies to adapters that have the 165 Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
166 capability set. 166 capability set.
167 * .. _`CEC-EVENT-PIN-HPD-LOW`: 167 * .. _`CEC-EVENT-PIN-HPD-LOW`:
168 168
169 - ``CEC_EVENT_PIN_HPD_LOW`` 169 - ``CEC_EVENT_PIN_HPD_LOW``
170 - 5 170 - 5
171 - Generated if the HPD pin goes from a h 171 - Generated if the HPD pin goes from a high voltage to a low voltage.
172 Only applies to adapters that have the 172 Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
173 capability set. When open() is called, 173 capability set. When open() is called, the HPD pin can be read and
174 if the HPD is low, then an initial eve 174 if the HPD is low, then an initial event will be generated for that
175 filehandle. 175 filehandle.
176 * .. _`CEC-EVENT-PIN-HPD-HIGH`: 176 * .. _`CEC-EVENT-PIN-HPD-HIGH`:
177 177
178 - ``CEC_EVENT_PIN_HPD_HIGH`` 178 - ``CEC_EVENT_PIN_HPD_HIGH``
179 - 6 179 - 6
180 - Generated if the HPD pin goes from a l 180 - Generated if the HPD pin goes from a low voltage to a high voltage.
181 Only applies to adapters that have the 181 Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
182 capability set. When open() is called, 182 capability set. When open() is called, the HPD pin can be read and
183 if the HPD is high, then an initial ev 183 if the HPD is high, then an initial event will be generated for that
184 filehandle. 184 filehandle.
185 * .. _`CEC-EVENT-PIN-5V-LOW`: 185 * .. _`CEC-EVENT-PIN-5V-LOW`:
186 186
187 - ``CEC_EVENT_PIN_5V_LOW`` 187 - ``CEC_EVENT_PIN_5V_LOW``
188 - 6 188 - 6
189 - Generated if the 5V pin goes from a hi 189 - Generated if the 5V pin goes from a high voltage to a low voltage.
190 Only applies to adapters that have the 190 Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
191 capability set. When open() is called, 191 capability set. When open() is called, the 5V pin can be read and
192 if the 5V is low, then an initial even 192 if the 5V is low, then an initial event will be generated for that
193 filehandle. 193 filehandle.
194 * .. _`CEC-EVENT-PIN-5V-HIGH`: 194 * .. _`CEC-EVENT-PIN-5V-HIGH`:
195 195
196 - ``CEC_EVENT_PIN_5V_HIGH`` 196 - ``CEC_EVENT_PIN_5V_HIGH``
197 - 7 197 - 7
198 - Generated if the 5V pin goes from a lo 198 - Generated if the 5V pin goes from a low voltage to a high voltage.
199 Only applies to adapters that have the 199 Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
200 capability set. When open() is called, 200 capability set. When open() is called, the 5V pin can be read and
201 if the 5V is high, then an initial eve 201 if the 5V is high, then an initial event will be generated for that
202 filehandle. 202 filehandle.
203 203
204 .. tabularcolumns:: |p{6.0cm}|p{0.6cm}|p{10.7c 204 .. tabularcolumns:: |p{6.0cm}|p{0.6cm}|p{10.7cm}|
205 205
206 .. _cec-event-flags: 206 .. _cec-event-flags:
207 207
208 .. flat-table:: CEC Event Flags 208 .. flat-table:: CEC Event Flags
209 :header-rows: 0 209 :header-rows: 0
210 :stub-columns: 0 210 :stub-columns: 0
211 :widths: 3 1 8 211 :widths: 3 1 8
212 212
213 * .. _`CEC-EVENT-FL-INITIAL-STATE`: 213 * .. _`CEC-EVENT-FL-INITIAL-STATE`:
214 214
215 - ``CEC_EVENT_FL_INITIAL_STATE`` 215 - ``CEC_EVENT_FL_INITIAL_STATE``
216 - 1 216 - 1
217 - Set for the initial events that are ge 217 - Set for the initial events that are generated when the device is
218 opened. See the table above for which 218 opened. See the table above for which events do this. This allows
219 applications to learn the initial stat 219 applications to learn the initial state of the CEC adapter at
220 open() time. 220 open() time.
221 * .. _`CEC-EVENT-FL-DROPPED-EVENTS`: 221 * .. _`CEC-EVENT-FL-DROPPED-EVENTS`:
222 222
223 - ``CEC_EVENT_FL_DROPPED_EVENTS`` 223 - ``CEC_EVENT_FL_DROPPED_EVENTS``
224 - 2 224 - 2
225 - Set if one or more events of the given 225 - Set if one or more events of the given event type have been dropped.
226 This is an indication that the applica 226 This is an indication that the application cannot keep up.
227 227
228 228
229 Return Value 229 Return Value
230 ============ 230 ============
231 231
232 On success 0 is returned, on error -1 and the 232 On success 0 is returned, on error -1 and the ``errno`` variable is set
233 appropriately. The generic error codes are des 233 appropriately. The generic error codes are described at the
234 :ref:`Generic Error Codes <gen-errors>` chapte 234 :ref:`Generic Error Codes <gen-errors>` chapter.
235 235
236 The :ref:`ioctl CEC_DQEVENT <CEC_DQEVENT>` can 236 The :ref:`ioctl CEC_DQEVENT <CEC_DQEVENT>` can return the following
237 error codes: 237 error codes:
238 238
239 EAGAIN 239 EAGAIN
240 This is returned when the filehandle is in 240 This is returned when the filehandle is in non-blocking mode and there
241 are no pending events. 241 are no pending events.
242 242
243 ERESTARTSYS 243 ERESTARTSYS
244 An interrupt (e.g. Ctrl-C) arrived while i 244 An interrupt (e.g. Ctrl-C) arrived while in blocking mode waiting for
245 events to arrive. 245 events to arrive.
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