drm/bridge: add ->edid_read hook and drm_bridge_edid_read()

[ Upstream commit d807ad80d811ba0c22adfd871e2a46491f80d6e2 ]

Add new struct drm_edid based ->edid_read hook and
drm_bridge_edid_read() function to call the hook.

v2: Include drm/drm_edid.h

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/9d08d22eaffcb9c59a2b677e45d7e61fc689bc2f.1706038510.git.jani.nikula@intel.com
Stable-dep-of: 171b711b26cc ("drm/bridge: lt8912b: do not return negative values from .get_modes()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

1 files changed, 45 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 39e68e45bb12..67354afbd716 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -27,8 +27,9 @@
 #include <linux/mutex.h>
 
 #include <drm/drm_atomic_state_helper.h>
-#include <drm/drm_debugfs.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_debugfs.h>
+#include <drm/drm_edid.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_file.h>
 #include <drm/drm_of.h>
@@ -1207,6 +1208,47 @@ int drm_bridge_get_modes(struct drm_bridge *bridge,
 EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
 
 /**
+ * drm_bridge_edid_read - read the EDID data of the connected display
+ * @bridge: bridge control structure
+ * @connector: the connector to read EDID for
+ *
+ * If the bridge supports output EDID retrieval, as reported by the
+ * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.edid_read to get
+ * the EDID and return it. Otherwise return NULL.
+ *
+ * If &drm_bridge_funcs.edid_read is not set, fall back to using
+ * drm_bridge_get_edid() and wrapping it in struct drm_edid.
+ *
+ * RETURNS:
+ * The retrieved EDID on success, or NULL otherwise.
+ */
+const struct drm_edid *drm_bridge_edid_read(struct drm_bridge *bridge,
+					    struct drm_connector *connector)
+{
+	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
+		return NULL;
+
+	/* Transitional: Fall back to ->get_edid. */
+	if (!bridge->funcs->edid_read) {
+		const struct drm_edid *drm_edid;
+		struct edid *edid;
+
+		edid = drm_bridge_get_edid(bridge, connector);
+		if (!edid)
+			return NULL;
+
+		drm_edid = drm_edid_alloc(edid, (edid->extensions + 1) * EDID_LENGTH);
+
+		kfree(edid);
+
+		return drm_edid;
+	}
+
+	return bridge->funcs->edid_read(bridge, connector);
+}
+EXPORT_SYMBOL_GPL(drm_bridge_edid_read);
+
+/**
  * drm_bridge_get_edid - get the EDID data of the connected display
  * @bridge: bridge control structure
  * @connector: the connector to read EDID for
@@ -1215,6 +1257,8 @@ EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
  * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
  * get the EDID and return it. Otherwise return NULL.
  *
+ * Deprecated. Prefer using drm_bridge_edid_read().
+ *
  * RETURNS:
  * The retrieved EDID on success, or NULL otherwise.
  */