From 54f38fcae536ea202ce7d6a359521492fba30c1f Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 4 Mar 2020 10:21:39 +0100 Subject: media: docs: move uAPI book to userspace-api/media Since 2017, there is an space reserved for userspace API, created by changeset 1d596dee3862 ("docs: Create a user-space API guide"). As the media subsystem was one of the first subsystems to use Sphinx, until this patch, we were keeping things on a separate place. Let's just use the new location, as having all uAPI altogether will likely make things easier for developers. Signed-off-by: Mauro Carvalho Chehab --- .../userspace-api/media/dvb/fe-read-status.rst | 72 ++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 Documentation/userspace-api/media/dvb/fe-read-status.rst (limited to 'Documentation/userspace-api/media/dvb/fe-read-status.rst') diff --git a/Documentation/userspace-api/media/dvb/fe-read-status.rst b/Documentation/userspace-api/media/dvb/fe-read-status.rst new file mode 100644 index 000000000000..cf781d463a20 --- /dev/null +++ b/Documentation/userspace-api/media/dvb/fe-read-status.rst @@ -0,0 +1,72 @@ +.. Permission is granted to copy, distribute and/or modify this +.. document under the terms of the GNU Free Documentation License, +.. Version 1.1 or any later version published by the Free Software +.. Foundation, with no Invariant Sections, no Front-Cover Texts +.. and no Back-Cover Texts. A copy of the license is included at +.. Documentation/userspace-api/media/fdl-appendix.rst. +.. +.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections + +.. _FE_READ_STATUS: + +******************** +ioctl FE_READ_STATUS +******************** + +Name +==== + +FE_READ_STATUS - Returns status information about the front-end. This call only requires - read-only access to the device + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, FE_READ_STATUS, unsigned int *status ) + :name: FE_READ_STATUS + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() `. + +``status`` + pointer to a bitmask integer filled with the values defined by enum + :c:type:`fe_status`. + + +Description +=========== + +All Digital TV frontend devices support the ``FE_READ_STATUS`` ioctl. It is +used to check about the locking status of the frontend after being +tuned. The ioctl takes a pointer to an integer where the status will be +written. + +.. note:: + + The size of status is actually sizeof(enum fe_status), with + varies according with the architecture. This needs to be fixed in the + future. + + +int fe_status +============= + +The fe_status parameter is used to indicate the current state and/or +state changes of the frontend hardware. It is produced using the enum +:c:type:`fe_status` values on a bitmask + + +Return Value +============ + +On success 0 is returned. + +On error -1 is returned, and the ``errno`` variable is set +appropriately. + +Generic error codes are described at the +:ref:`Generic Error Codes ` chapter. -- cgit v1.2.3