Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 244 insertions, 0 deletions

diff --git a/Documentation/media/uapi/cec/cec-ioc-dqevent.rst b/Documentation/media/uapi/cec/cec-ioc-dqevent.rst
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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _CEC_DQEVENT:
+
+*****************
+ioctl CEC_DQEVENT
+*****************
+
+Name
+====
+
+CEC_DQEVENT - Dequeue a CEC event
+
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, CEC_DQEVENT, struct cec_event *argp )
+    :name: CEC_DQEVENT
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :c:func:`open() <cec-open>`.
+
+``argp``
+
+
+Description
+===========
+
+CEC devices can send asynchronous events. These can be retrieved by
+calling :c:func:`CEC_DQEVENT`. 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 :ref:`CEC_EVENT_STATE_CHANGE <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.
+
+.. tabularcolumns:: |p{1.2cm}|p{2.9cm}|p{13.4cm}|
+
+.. c:type:: cec_event_state_change
+
+.. flat-table:: struct cec_event_state_change
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 8
+
+    * - __u16
+      - ``phys_addr``
+      - The current physical address. This is ``CEC_PHYS_ADDR_INVALID`` if no
+        valid physical address is set.
+    * - __u16
+      - ``log_addr_mask``
+      - The current set of claimed logical addresses. This is 0 if no logical
+        addresses are claimed or if ``phys_addr`` is ``CEC_PHYS_ADDR_INVALID``.
+	If bit 15 is set (``1 << CEC_LOG_ADDR_UNREGISTERED``) then this device
+	has the unregistered logical address. In that case all other bits are 0.
+
+
+.. c:type:: cec_event_lost_msgs
+
+.. tabularcolumns:: |p{1.0cm}|p{2.0cm}|p{14.5cm}|
+
+.. flat-table:: struct cec_event_lost_msgs
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 16
+
+    * - __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.
+
+
+.. tabularcolumns:: |p{1.0cm}|p{4.4cm}|p{2.5cm}|p{9.6cm}|
+
+.. c:type:: cec_event
+
+.. flat-table:: struct cec_event
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 1 8
+
+    * - __u64
+      - ``ts``
+      - :cspan:`1`\ Timestamp of the event in ns.
+
+	The timestamp has been taken from the ``CLOCK_MONOTONIC`` clock.
+
+	To access the same clock from userspace use :c:func:`clock_gettime`.
+    * - __u32
+      - ``event``
+      - :cspan:`1` The CEC event type, see :ref:`cec-events`.
+    * - __u32
+      - ``flags``
+      - :cspan:`1` Event flags, see :ref:`cec-event-flags`.
+    * - union
+      - (anonymous)
+      -
+      -
+    * -
+      - struct cec_event_state_change
+      - ``state_change``
+      - The new adapter state as sent by the :ref:`CEC_EVENT_STATE_CHANGE <CEC-EVENT-STATE-CHANGE>`
+	event.
+    * -
+      - struct cec_event_lost_msgs
+      - ``lost_msgs``
+      - The number of lost messages as sent by the :ref:`CEC_EVENT_LOST_MSGS <CEC-EVENT-LOST-MSGS>`
+	event.
+
+
+.. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{11.0cm}|
+
+.. _cec-events:
+
+.. flat-table:: CEC Events Types
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 1 16
+
+    * .. _`CEC-EVENT-STATE-CHANGE`:
+
+      - ``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.
+    * .. _`CEC-EVENT-LOST-MSGS`:
+
+      - ``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-PIN-CEC-LOW`:
+
+      - ``CEC_EVENT_PIN_CEC_LOW``
+      - 3
+      - Generated if the CEC pin goes from a high voltage to a low voltage.
+        Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
+	capability set.
+    * .. _`CEC-EVENT-PIN-CEC-HIGH`:
+
+      - ``CEC_EVENT_PIN_CEC_HIGH``
+      - 4
+      - Generated if the CEC pin goes from a low voltage to a high voltage.
+        Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
+	capability set.
+    * .. _`CEC-EVENT-PIN-HPD-LOW`:
+
+      - ``CEC_EVENT_PIN_HPD_LOW``
+      - 5
+      - Generated if the HPD pin goes from a high voltage to a low voltage.
+	Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
+	capability set. When open() is called, the HPD pin can be read and
+	if the HPD is low, then an initial event will be generated for that
+	filehandle.
+    * .. _`CEC-EVENT-PIN-HPD-HIGH`:
+
+      - ``CEC_EVENT_PIN_HPD_HIGH``
+      - 6
+      - Generated if the HPD pin goes from a low voltage to a high voltage.
+	Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
+	capability set. When open() is called, the HPD pin can be read and
+	if the HPD is high, then an initial event will be generated for that
+	filehandle.
+    * .. _`CEC-EVENT-PIN-5V-LOW`:
+
+      - ``CEC_EVENT_PIN_5V_LOW``
+      - 6
+      - Generated if the 5V pin goes from a high voltage to a low voltage.
+	Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
+	capability set. When open() is called, the 5V pin can be read and
+	if the 5V is low, then an initial event will be generated for that
+	filehandle.
+    * .. _`CEC-EVENT-PIN-5V-HIGH`:
+
+      - ``CEC_EVENT_PIN_5V_HIGH``
+      - 7
+      - Generated if the 5V pin goes from a low voltage to a high voltage.
+	Only applies to adapters that have the ``CEC_CAP_MONITOR_PIN``
+	capability set. When open() is called, the 5V pin can be read and
+	if the 5V is high, then an initial event will be generated for that
+	filehandle.
+
+
+.. tabularcolumns:: |p{6.0cm}|p{0.6cm}|p{10.9cm}|
+
+.. _cec-event-flags:
+
+.. flat-table:: CEC Event Flags
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 1 8
+
+    * .. _`CEC-EVENT-FL-INITIAL-STATE`:
+
+      - ``CEC_EVENT_FL_INITIAL_STATE``
+      - 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.
+    * .. _`CEC-EVENT-FL-DROPPED-EVENTS`:
+
+      - ``CEC_EVENT_FL_DROPPED_EVENTS``
+      - 2
+      - Set if one or more events of the given event type have been dropped.
+        This is an indication that the application cannot keep up.
+
+
+
+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.
+
+The :ref:`ioctl CEC_DQEVENT <CEC_DQEVENT>` can return the following
+error codes:
+
+EAGAIN
+    This is returned when the filehandle is in non-blocking mode and there
+    are no pending events.
+
+ERESTARTSYS
+    An interrupt (e.g. Ctrl-C) arrived while in blocking mode waiting for
+    events to arrive.