[PATCH v1 07/13] drm/probe-helper: add .get_edid() callback

[Jani Nikula <jani.nikula@xxxxxxxxx>]

Add a hook for custom .get_edid() when .get_modes() is not set.

Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
 drivers/gpu/drm/drm_probe_helper.c       | 11 +++++++++--
 include/drm/drm_modeset_helper_vtables.h | 21 ++++++++++++++++++---
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 9df17f0ae225..42481dc9e6db 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -361,12 +361,19 @@ static int drm_helper_probe_get_modes(struct drm_connector *connector)
 	int count;
 
 	if (connector_funcs->get_modes) {
+		/* No point in having both set */
+		drm_WARN_ON_ONCE(connector->dev, connector_funcs->get_edid);
+
 		count = connector_funcs->get_modes(connector);
 	} else {
 		const struct drm_edid *drm_edid;
 
-		/* Note: This requires connector->ddc is set */
-		drm_edid = drm_edid_read(connector);
+		if (connector_funcs->get_edid) {
+			drm_edid = connector_funcs->get_edid(connector);
+		} else {
+			/* Note: This requires connector->ddc is set */
+			drm_edid = drm_edid_read(connector);
+		}
 
 		/* Update modes etc. from the EDID */
 		count = drm_edid_connector_update(connector, drm_edid);
diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
index b4402bc64e57..f4defbdf1768 100644
--- a/include/drm/drm_modeset_helper_vtables.h
+++ b/include/drm/drm_modeset_helper_vtables.h
@@ -49,6 +49,7 @@
  */
 
 enum mode_set_atomic;
+struct drm_edid;
 struct drm_writeback_connector;
 struct drm_writeback_job;
 
@@ -894,9 +895,10 @@ struct drm_connector_helper_funcs {
 	 * libraries always call this with the &drm_mode_config.connection_mutex
 	 * held. Because of this it's safe to inspect &drm_connector->state.
 	 *
-	 * This callback is optional. By default, it reads the EDID using
-	 * drm_edid_read() and updates the connector display info, modes, and
-	 * properties using drm_edid_connector_update().
+	 * This callback is optional. By default, it reads the EDID using the
+	 * .get_edid() callback if set, drm_edid_read() otherwise, and updates
+	 * the connector display info, modes, and properties using
+	 * drm_edid_connector_update().
 	 *
 	 * RETURNS:
 	 *
@@ -904,6 +906,19 @@ struct drm_connector_helper_funcs {
 	 */
 	int (*get_modes)(struct drm_connector *connector);
 
+	/**
+	 * @get_edid:
+	 *
+	 * If the get_modes() callback is not set, this function gets called to
+	 * retrieve the EDID. This callback is optional. By default,
+	 * drm_edid_read() is used.
+	 *
+	 * This function must return a copy of the EDID; the returned pointer
+	 * will be freed using drm_edid_free(). Usually it would be a copy of a
+	 * previously cached EDID.
+	 */
+	const struct drm_edid *(*get_edid)(struct drm_connector *connector);
+
 	/**
 	 * @detect_ctx:
 	 *
-- 
2.30.2