summaryrefslogtreecommitdiff
path: root/Documentation/userspace-api/media/dvb/fe-read-signal-strength.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/userspace-api/media/dvb/fe-read-signal-strength.rst')
-rw-r--r--Documentation/userspace-api/media/dvb/fe-read-signal-strength.rst57
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/dvb/fe-read-signal-strength.rst b/Documentation/userspace-api/media/dvb/fe-read-signal-strength.rst
new file mode 100644
index 000000000000..df79837de47d
--- /dev/null
+++ b/Documentation/userspace-api/media/dvb/fe-read-signal-strength.rst
@@ -0,0 +1,57 @@
+.. 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_SIGNAL_STRENGTH:
+
+***********************
+FE_READ_SIGNAL_STRENGTH
+***********************
+
+Name
+====
+
+FE_READ_SIGNAL_STRENGTH
+
+.. attention:: This ioctl is deprecated.
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, FE_READ_SIGNAL_STRENGTH, uint16_t *strength)
+ :name: FE_READ_SIGNAL_STRENGTH
+
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :c:func:`open() <dvb-fe-open>`.
+
+``strength``
+ The signal strength value is stored into \*strength.
+
+
+Description
+===========
+
+This ioctl call returns the signal strength value for the signal
+currently received by the front-end. For this command, read-only access
+to the device is sufficient.
+
+
+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 <gen-errors>` chapter.