media: rc: describe rc protocols and their scancodes

This lists the rc protocols the kernel knows about and how they are
converted to and from scancodes.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/uapi/rc/lirc-dev-intro.rst

@@ -66,11 +66,12 @@ on the following table.
 
     For transmitting (aka sending), create a ``struct lirc_scancode`` with
     the desired scancode set in the ``scancode`` member, :c:type:`rc_proto`
-    set the IR protocol, and all other members set to 0. Write this struct to
-    the lirc device.
+    set to the :ref:`IR protocol <Remote_controllers_Protocols>`, and all other
+    members set to 0. Write this struct to the lirc device.
 
-    For receiving, you read ``struct lirc_scancode`` from the lirc device,
-    with ``scancode`` set to the received scancode and the IR protocol
+    For receiving, you read ``struct lirc_scancode`` from the LIRC device.
+    The ``scancode`` field is set to the received scancode and the
+    :ref:`IR protocol <Remote_controllers_Protocols>` is set in
     :c:type:`rc_proto`. If the scancode maps to a valid key code, this is set
     in the ``keycode`` field, else it is set to ``KEY_RESERVED``.
 
@@ -146,7 +147,8 @@ on the following table.
 BPF based IR decoder
 ********************
 
-The kernel has support for decoding the most common IR protocols, but there
+The kernel has support for decoding the most common
+:ref:`IR protocols <Remote_controllers_Protocols>`, but there
 are many protocols which are not supported. To support these, it is possible
 to load an BPF program which does the decoding. This can only be done on
 LIRC devices which support reading raw IR.

Documentation/media/uapi/rc/lirc-read.rst

@@ -62,7 +62,8 @@ read from the chardev.
 Alternatively, :ref:`LIRC_MODE_SCANCODE <lirc-mode-scancode>` can be available,
 in this mode scancodes which are either decoded by software decoders, or
 by hardware decoders. The :c:type:`rc_proto` member is set to the
-protocol used for transmission, and ``scancode`` to the decoded scancode,
+:ref:`IR protocol <Remote_controllers_Protocols>`
+used for transmission, and ``scancode`` to the decoded scancode,
 and the ``keycode`` set to the keycode or ``KEY_RESERVED``.
 
 

Documentation/media/uapi/rc/lirc-write.rst

@@ -64,7 +64,8 @@ driver returns ``EINVAL``.
 When in :ref:`LIRC_MODE_SCANCODE <lirc-mode-scancode>` mode, one
 ``struct lirc_scancode`` must be written to the chardev at a time, else
 ``EINVAL`` is returned. Set the desired scancode in the ``scancode`` member,
-and the protocol in the :c:type:`rc_proto`: member. All other members must be
+and the :ref:`IR protocol <Remote_controllers_Protocols>` in the
+:c:type:`rc_proto`: member. All other members must be
 set to 0, else ``EINVAL`` is returned. If there is no protocol encoder
 for the protocol or the scancode is not valid for the specified protocol,
 ``EINVAL`` is returned. The write function blocks until the scancode