docs: media: Allow creating cross-references for RC ABI

Now that Documentation/ABI is processed by automarkup, let it
generate cross-references for RC sysfs devnodes.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>
Link: https://lore.kernel.org/r/7c2f9a[e-mail]

Documentation/sphinx/automarkup.py

···
     # Associate each regex with the function that will markup its matches
     #
     markup_func_sphinx2 = {RE_doc: markup_doc_ref,
-                           RE_abi_file: markup_abi_ref,
+                           RE_abi_file: markup_abi_file_ref,
                            RE_abi_symbol: markup_abi_ref,
                            RE_function: markup_c_ref,
                            RE_generic_type: markup_c_ref}
 
     markup_func_sphinx3 = {RE_doc: markup_doc_ref,
-                           RE_abi_file: markup_abi_ref,
+                           RE_abi_file: markup_abi_file_ref,
                            RE_abi_symbol: markup_abi_ref,
                            RE_function: markup_func_ref_sphinx3,
                            RE_struct: markup_c_ref,
···
         return nodes.Text(match.group(0))
 
 #
-# Try to replace a documentation reference of the form Documentation/ABI/...
+# Try to replace a documentation reference for ABI symbols and files
 # with a cross reference to that page
 #
-def markup_abi_ref(docname, app, match):
+def markup_abi_ref(docname, app, match, warning=False):
     stddom = app.env.domains['std']
     #
     # Go through the dance of getting an xref out of the std domain
···
 
     # Kernel ABI doesn't describe such file or symbol
     if not target:
+        if warning:
+            kernel_abi.log.warning("%s not found", fname)
         return nodes.Text(match.group(0))
 
     pxref = addnodes.pending_xref('', refdomain = 'std', reftype = 'ref',
···
         return xref
     else:
         return nodes.Text(match.group(0))
+
+#
+# Variant of markup_abi_ref() that warns whan a reference is not found
+#
+def markup_abi_file_ref(docname, app, match):
+    return markup_abi_ref(docname, app, match, warning=True)
+
 
 def get_c_namespace(app, docname):
     source = app.env.doc2path(docname)

Documentation/userspace-api/media/rc/rc-sysfs-nodes.rst

···
 Remote Controller's sysfs nodes
 *******************************
 
-As defined at ``Documentation/ABI/testing/sysfs-class-rc``, those are
+As defined at Documentation/ABI/testing/sysfs-class-rc, those are
 the sysfs nodes that control the Remote Controllers: