drm/bridge: Add devm_drm_bridge_add()

This adds a devm managed version of drm_bridge_add(). Like other
"devm" function listed in drm_bridge.h, this function takes an
explicit "dev" to use for the lifetime management. A few notes:
* In general we have a "struct device" for bridges that makes a good
  candidate for where the lifetime matches exactly what we want.
* The "bridge->dev->dev" device appears to be the encoder
  device. That's not the right device to use for lifetime management.

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220510122726.v3.3.Iba4b9bf6c7a1ee5ea2835ad7bd5eaf84d7688520@changeid

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index c96847f..e275b4c 100644 (file)
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -170,6 +170,29 @@ void drm_bridge_add(struct drm_bridge *bridge)
 }
 EXPORT_SYMBOL(drm_bridge_add);
 
+static void drm_bridge_remove_void(void *bridge)
+{
+       drm_bridge_remove(bridge);
+}
+
+/**
+ * devm_drm_bridge_add - devm managed version of drm_bridge_add()
+ *
+ * @dev: device to tie the bridge lifetime to
+ * @bridge: bridge control structure
+ *
+ * This is the managed version of drm_bridge_add() which automatically
+ * calls drm_bridge_remove() when @dev is unbound.
+ *
+ * Return: 0 if no error or negative error code.
+ */
+int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge)
+{
+       drm_bridge_add(bridge);
+       return devm_add_action_or_reset(dev, drm_bridge_remove_void, bridge);
+}
+EXPORT_SYMBOL(devm_drm_bridge_add);
+
 /**
  * drm_bridge_remove - remove the given bridge from the global bridge list
  *

diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index f27b406..42aec86 100644 (file)
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -796,6 +796,7 @@ drm_priv_to_bridge(struct drm_private_obj *priv)
 }
 
 void drm_bridge_add(struct drm_bridge *bridge);
+int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
 void drm_bridge_remove(struct drm_bridge *bridge);
 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
                      struct drm_bridge *previous,