[PATCH RFC v2 02/12] drm/connector: add functionality to register connectors to a global list

[Heiko Stuebner]

This allows standalone connectors to be registered and found again
through their devicetree node when going through their connection graph.

Setting the of_node property is of course still optional, as it is not
necessary in most cases to lookup connectors that are part of a bigger
component.

Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
 drivers/gpu/drm/drm_crtc.c | 41 +++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_crtc.h     |  7 +++++++
 2 files changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index b63e69d..8b49ea7 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -852,6 +852,47 @@ static void drm_connector_get_cmdline_mode(struct 
drm_connector *connector)
                      mode->interlace ?  " interlaced" : "");
 }

+static DEFINE_MUTEX(connector_lock);
+static LIST_HEAD(connector_list);
+
+int drm_connector_add(struct drm_connector *connector)
+{
+       mutex_lock(&connector_lock);
+       list_add_tail(&connector->list, &connector_list);
+       mutex_unlock(&connector_lock);
+
+       return 0;
+}
+EXPORT_SYMBOL(drm_connector_add);
+
+void drm_connector_remove(struct drm_connector *connector)
+{
+       mutex_lock(&connector_lock);
+       list_del_init(&connector->list);
+       mutex_unlock(&connector_lock);
+}
+EXPORT_SYMBOL(drm_connector_remove);
+
+#ifdef CONFIG_OF
+struct drm_connector *of_drm_find_connector(struct device_node *np)
+{
+       struct drm_connector *connector;
+
+       mutex_lock(&connector_lock);
+
+       list_for_each_entry(connector, &connector_list, list) {
+               if (connector->of_node == np) {
+                       mutex_unlock(&connector_lock);
+                       return connector;
+               }
+       }
+
+       mutex_unlock(&connector_lock);
+       return NULL;
+}
+EXPORT_SYMBOL(of_drm_find_connector);
+#endif
+
 /**
  * drm_connector_init - Init a preallocated connector
  * @dev: DRM device
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 76994ba..37b230b 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -671,6 +671,10 @@ struct drm_encoder {
  */
 struct drm_connector {
        struct drm_device *dev;
+#ifdef CONFIG_OF
+       struct device_node *of_node;
+#endif
+       struct list_head list;
        struct device *kdev;
        struct device_attribute *attr;
        struct list_head head;
@@ -1213,6 +1217,9 @@ static inline uint32_t drm_crtc_mask(struct drm_crtc 
*crtc)

 extern void drm_connector_ida_init(void);
 extern void drm_connector_ida_destroy(void);
+extern int drm_connector_add(struct drm_connector *connector);
+extern void drm_connector_remove(struct drm_connector *connector);
+extern struct drm_connector *of_drm_find_connector(struct device_node *np);
 extern int drm_connector_init(struct drm_device *dev,
                              struct drm_connector *connector,
                              const struct drm_connector_funcs *funcs,
-- 
2.1.4