drm: document drm_display_info

We seem to have a bit a mess in how to describe the bus formats, with
a multitude of competing ways. Might be best to consolidate it all and
use MEDIA_BUS_FMT_ also for the hdmi color formats and high color
modes.

Also move all the display_info related functions into drm_connector.c
(there's only one) to group it all together. I did decided against
also moving the edid related display info functions, they seem to fit
better in drm_edid.c. Instead sprinkle a few cross references around.
While at that reduce the kerneldoc for static functions, there's not
point in documenting internals with that much detail really.

v2: Fix typo and move misplaced hunk (Sean).

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-19-git-send-email-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 6a05517..26bb78c7 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -506,6 +506,40 @@
 };
 DRM_ENUM_NAME_FN(drm_get_dpms_name, drm_dpms_enum_list)
 
+/**
+ * drm_display_info_set_bus_formats - set the supported bus formats
+ * @info: display info to store bus formats in
+ * @formats: array containing the supported bus formats
+ * @num_formats: the number of entries in the fmts array
+ *
+ * Store the supported bus formats in display info structure.
+ * See MEDIA_BUS_FMT_* definitions in include/uapi/linux/media-bus-format.h for
+ * a full list of available formats.
+ */
+int drm_display_info_set_bus_formats(struct drm_display_info *info,
+				     const u32 *formats,
+				     unsigned int num_formats)
+{
+	u32 *fmts = NULL;
+
+	if (!formats && num_formats)
+		return -EINVAL;
+
+	if (formats && num_formats) {
+		fmts = kmemdup(formats, sizeof(*formats) * num_formats,
+			       GFP_KERNEL);
+		if (!fmts)
+			return -ENOMEM;
+	}
+
+	kfree(info->bus_formats);
+	info->bus_formats = fmts;
+	info->num_bus_formats = num_formats;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_display_info_set_bus_formats);
+
 /* Optional connector properties. */
 static const struct drm_prop_enum_list drm_scaling_mode_enum_list[] = {
 	{ DRM_MODE_SCALE_NONE, "None" },