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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2017-09-03 20:50:17 -0400
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-09-05 06:23:07 -0400
commitbd9049edc66e13e868f819c39844f60443e70817 (patch)
tree82cbfd5b648d7f11baf3bc9ba6ac8771efa609d4
parent56d51b65bcc7a5780663abd579fb6f039616b347 (diff)
media: ca docs: document CA_SET_DESCR ioctl and structs
The av7110 driver uses CA_SET_DESCR to store the descrambler control words at the CA descrambler slots. Document it. Thanks-to: Honza Petrouš <jpetrous@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
-rw-r--r--Documentation/media/uapi/dvb/ca-set-descr.rst15
-rw-r--r--include/uapi/linux/dvb/ca.h9
2 files changed, 10 insertions, 14 deletions
diff --git a/Documentation/media/uapi/dvb/ca-set-descr.rst b/Documentation/media/uapi/dvb/ca-set-descr.rst
index 9c484317d55c..a6c47205ffd8 100644
--- a/Documentation/media/uapi/dvb/ca-set-descr.rst
+++ b/Documentation/media/uapi/dvb/ca-set-descr.rst
@@ -28,22 +28,11 @@ Arguments
``msg``
Pointer to struct :c:type:`ca_descr`.
-.. c:type:: ca_descr
-
-.. code-block:: c
-
- struct ca_descr {
- unsigned int index;
- unsigned int parity;
- unsigned char cw[8];
- };
-
-
Description
-----------
-.. note:: This ioctl is undocumented. Documentation is welcome.
-
+CA_SET_DESCR is used for feeding descrambler CA slots with descrambling
+keys (refered as control words).
Return Value
------------
diff --git a/include/uapi/linux/dvb/ca.h b/include/uapi/linux/dvb/ca.h
index 7ee641b4124c..c36fdb8e2733 100644
--- a/include/uapi/linux/dvb/ca.h
+++ b/include/uapi/linux/dvb/ca.h
@@ -109,9 +109,16 @@ struct ca_msg {
unsigned char msg[256];
};
+/**
+ * struct ca_descr - CA descrambler control words info
+ *
+ * @index: CA Descrambler slot
+ * @parity: control words parity, where 0 means even and 1 means odd
+ * @cw: CA Descrambler control words
+ */
struct ca_descr {
unsigned int index;
- unsigned int parity; /* 0 == even, 1 == odd */
+ unsigned int parity;
unsigned char cw[8];
};