drm: Move drm_set_preferred_mode() helper from drm_edid to drm_modes

The helper is generic, it doesn't use the opaque EDID type struct drm_edid
and is also used by drivers that only support non-probeable displays such
as fixed panels.

These drivers add a list of modes using drm_mode_probed_add() and then set
a preferred mode using the drm_set_preferred_mode() helper.

It seems more logical to have the helper definition in drm_modes.o instead
of drm_edid.o, since the former contains modes helper while the latter has
helpers to manage the EDID information.

Since both drm_edid.o and drm_modes.o object files are built-in the drm.o
object, there are no functional changes. But besides being a more logical
place for this helper, it could also allow to eventually make drm_edid.o
optional and not included in drm.o if only fixed panels must be supported
in a given system.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240102122208.3103597-1-javierm@redhat.com

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index ac9a406250c5..45238ec5df1b 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -2754,3 +2754,25 @@ bool drm_mode_is_420(const struct drm_display_info *display,
 		drm_mode_is_420_also(display, mode);
 }
 EXPORT_SYMBOL(drm_mode_is_420);
+
+/**
+ * drm_set_preferred_mode - Sets the preferred mode of a connector
+ * @connector: connector whose mode list should be processed
+ * @hpref: horizontal resolution of preferred mode
+ * @vpref: vertical resolution of preferred mode
+ *
+ * Marks a mode as preferred if it matches the resolution specified by @hpref
+ * and @vpref.
+ */
+void drm_set_preferred_mode(struct drm_connector *connector,
+			    int hpref, int vpref)
+{
+	struct drm_display_mode *mode;
+
+	list_for_each_entry(mode, &connector->probed_modes, head) {
+		if (mode->hdisplay == hpref &&
+		    mode->vdisplay == vpref)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+	}
+}
+EXPORT_SYMBOL(drm_set_preferred_mode);