diff options
Diffstat (limited to 'Documentation/media/uapi/cec/cec-ioc-receive.rst')
| -rw-r--r-- | Documentation/media/uapi/cec/cec-ioc-receive.rst | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/Documentation/media/uapi/cec/cec-ioc-receive.rst b/Documentation/media/uapi/cec/cec-ioc-receive.rst index ae5a39ade45f..d585b1bba6ac 100644 --- a/Documentation/media/uapi/cec/cec-ioc-receive.rst +++ b/Documentation/media/uapi/cec/cec-ioc-receive.rst @@ -16,28 +16,32 @@ CEC_RECEIVE, CEC_TRANSMIT - Receive or transmit a CEC message Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct cec_msg *argp ) +.. c:function:: int ioctl( int fd, CEC_RECEIVE, struct cec_msg *argp ) + :name: CEC_RECEIVE + +.. c:function:: int ioctl( int fd, CEC_TRANSMIT, struct cec_msg *argp ) + :name: CEC_TRANSMIT Arguments ========= ``fd`` - File descriptor returned by :ref:`open() <cec-func-open>`. - -``request`` - CEC_RECEIVE, CEC_TRANSMIT + File descriptor returned by :c:func:`open() <cec-open>`. ``argp`` - + Pointer to struct cec_msg. Description =========== -.. note:: This documents the proposed CEC API. This API is not yet finalized +.. 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 -``timeout`` field of :c:type:`struct cec_msg` and pass it to :ref:`ioctl CEC_RECEIVE <CEC_RECEIVE>`. +``timeout`` field of struct :c:type:`cec_msg` and pass it to +:ref:`ioctl CEC_RECEIVE <CEC_RECEIVE>`. 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`` @@ -51,9 +55,9 @@ A received message can be: 2. the result of an earlier non-blocking transmit (the ``sequence`` field will be non-zero). -To send a CEC message the application has to fill in the -:c:type:`struct cec_msg` and pass it to -:ref:`ioctl CEC_TRANSMIT <CEC_TRANSMIT>`. The :ref:`ioctl CEC_TRANSMIT <CEC_TRANSMIT>` is only available if +To send a CEC message the application has to fill in the struct +:c:type:` cec_msg` and pass it to :ref:`ioctl CEC_TRANSMIT <CEC_TRANSMIT>`. +The :ref:`ioctl CEC_TRANSMIT <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. The transmit queue has enough room for 18 messages (about 1 second worth @@ -71,7 +75,11 @@ checked against the received messages to find the corresponding transmit result. -.. _cec-msg: +.. tabularcolumns:: |p{1.0cm}|p{3.5cm}|p{13.0cm}| + +.. c:type:: cec_msg + +.. cssclass:: longtable .. flat-table:: struct cec_msg :header-rows: 0 @@ -87,7 +95,7 @@ result. - Timestamp in ns of when the last byte of the message was transmitted. The timestamp has been taken from the ``CLOCK_MONOTONIC`` clock. To access - the same clock from userspace use :c:func:`clock_gettime(2)`. + the same clock from userspace use :c:func:`clock_gettime`. - .. row 2 @@ -97,7 +105,7 @@ result. - Timestamp in ns of when the last byte of the message was received. The timestamp has been taken from the ``CLOCK_MONOTONIC`` clock. To access - the same clock from userspace use :c:func:`clock_gettime(2)`. + the same clock from userspace use :c:func:`clock_gettime`. - .. row 3 @@ -247,6 +255,7 @@ result. valid if the :ref:`CEC_TX_STATUS_ERROR <CEC-TX-STATUS-ERROR>` status bit is set. +.. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{11.0cm}| .. _cec-tx-status: @@ -315,6 +324,7 @@ result. be set to explain which failures were seen. +.. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{11.0cm}| .. _cec-rx-status: |