linux-kernel - [PATCH 1/5] drm/bridge: Add drm_bridge_find_by

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Message-Id: <20240122163220.110788-2-sui.jingfeng@linux.dev>
Date: Tue, 23 Jan 2024 00:32:16 +0800
From: Sui Jingfeng <sui.jingfeng@...ux.dev>
To: David Airlie <airlied@...il.com>
Cc: Neil Armstrong <neil.armstrong@...aro.org>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	Daniel Vetter <daniel@...ll.ch>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Sui Jingfeng <sui.jingfeng@...ux.dev>
Subject: [PATCH 1/5] drm/bridge: Add drm_bridge_find_by_fwnode() helper

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@...ux.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@...sung.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