drm: make mode_valid callback optional
Many drm connectors do not need mode validation.
The patch makes this callback optional and removes dumb implementations.
v2: Rebase:
- imx move to a shared (but still dummy) ->mode_valid implementation.
- probe helpers have been extracted to drm_probe_helper.c
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 677a025..c72e146 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -1903,8 +1903,8 @@
<para>
The function filters out modes larger than
<parameter>max_width</parameter> and <parameter>max_height</parameter>
- if specified. It then calls the connector
- <methodname>mode_valid</methodname> helper operation for each mode in
+ if specified. It then calls the optional connector
+ <methodname>mode_valid</methodname> helper operation for each mode in
the probed list to check whether the mode is valid for the connector.
</para>
</listitem>
@@ -2265,7 +2265,7 @@
<para>
Verify whether a mode is valid for the connector. Return MODE_OK for
supported modes and one of the enum drm_mode_status values (MODE_*)
- for unsupported modes. This operation is mandatory.
+ for unsupported modes. This operation is optional.
</para>
<para>
As the mode rejection reason is currently not used beside for