[PATCH 1/5] drm/bridge: Add drm_bridge_find_by_fwnode() helper

Sui Jingfeng
2024-01-22T16:32:32Z

Because ACPI based systems only has the fwnode associated, the of_node
member of struct device is NULL. To order to move things forward, we add
drm_bridge_find_by_fwnode() to extend the support.

Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
---
drivers/gpu/drm/drm_bridge.c | 33 +++++++++++++++++++++++++++++++++
include/drm/drm_bridge.h | 4 ++++
2 files changed, 37 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index cee3188adf3d..ffd969adc2fb 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -1347,6 +1347,39 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
EXPORT_SYMBOL(of_drm_find_bridge);
#endif

+/**
+ * drm_bridge_find_by_fwnode - Find the bridge corresponding to the associated fwnode
+ *
+ * @fwnode: fwnode for which to find the matching drm_bridge
+ *
+ * This function looks up a drm_bridge based on its associated fwnode.
+ *
+ * RETURNS:
+ * A reference to the drm_bridge control structure if found, NULL on failure.
+ */
+struct drm_bridge *drm_bridge_find_by_fwnode(struct fwnode_handle *fwnode)
+{
+ struct drm_bridge *ret = NULL;
+ struct drm_bridge *bridge;
+
+ if (!fwnode)
+ return NULL;
+
+ mutex_lock(&bridge_lock);
+
+ list_for_each_entry(bridge, &bridge_list, list) {
+ if (bridge->fwnode == fwnode) {
+ ret = bridge;
+ break;
+ }
+ }
+
+ mutex_unlock(&bridge_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_bridge_find_by_fwnode);
+
MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
MODULE_DESCRIPTION("DRM bridge infrastructure");
MODULE_LICENSE("GPL and additional rights");
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index e39da5807ba7..fe3d5f4bf37f 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -720,6 +720,8 @@ struct drm_bridge {
struct list_head chain_node;
/** @of_node: device node pointer to the bridge */
struct device_node *of_node;
+ /** @fwnode: associated fwnode supplied by platform firmware */
+ struct fwnode_handle *fwnode;
/** @list: to keep track of all added bridges */
struct list_head list;
/**
@@ -796,6 +798,8 @@ static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
}
#endif

+struct drm_bridge *drm_bridge_find_by_fwnode(struct fwnode_handle *fwnode);
+
/**
* drm_bridge_get_next_bridge() - Get the next bridge in the chain
* @bridge: bridge object
--
2.25.1