From: Chaoyi Chen <[email protected]> Add a new API to check whether a DisplayPort HPD bridge has already been registered. This helps avoid duplicate registration of the same HPD bridge, although the current framework allows doing so.
Suggested-by: Sebastian Reichel <[email protected]> Signed-off-by: Chaoyi Chen <[email protected]> --- drivers/gpu/drm/bridge/aux-hpd-bridge.c | 42 ++++++++++++++++++++++++- include/drm/bridge/aux-bridge.h | 6 ++++ 2 files changed, 47 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c index f02a38a2638a..a56c88eba005 100644 --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c @@ -12,6 +12,8 @@ #include <drm/drm_bridge.h> #include <drm/bridge/aux-bridge.h> +#define DRM_AUX_HPD_BRIDGE_NAME "dp_hpd_bridge" + static DEFINE_IDA(drm_aux_hpd_bridge_ida); struct drm_aux_hpd_bridge_data { @@ -36,6 +38,44 @@ static void drm_aux_hpd_bridge_free_adev(void *_adev) auxiliary_device_uninit(_adev); } +static int hpd_bridge_match(struct device *dev, const void *data) +{ + const struct device_node *np = data; + struct auxiliary_device *adev; + + if (!dev_is_auxiliary(dev)) + return 0; + + adev = to_auxiliary_dev(dev); + if (strcmp(adev->name, DRM_AUX_HPD_BRIDGE_NAME)) + return 0; + + return adev->dev.platform_data == np; +} + +/** + * drm_dev_has_dp_hpd_bridge - check whether a HPD DisplayPort bridge is registered + * @parent: device instance providing this bridge + * @np: device node pointer corresponding to this bridge instance + * + * Walk the children of @parent and check whether a HPD DisplayPort bridge for + * the given @np has already been registered via devm_drm_dp_hpd_bridge_add(). + * + * Return: true if a HPD bridge for @parent / @np already exists, false otherwise + */ +bool drm_dev_has_dp_hpd_bridge(struct device *parent, struct device_node *np) +{ + struct device *child; + + child = device_find_child(parent, np, hpd_bridge_match); + if (child) { + put_device(child); + return true; + } + return false; +} +EXPORT_SYMBOL_GPL(drm_dev_has_dp_hpd_bridge); + /** * devm_drm_dp_hpd_bridge_alloc - allocate a HPD DisplayPort bridge * @parent: device instance providing this bridge @@ -63,7 +103,7 @@ struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, str } adev->id = ret; - adev->name = "dp_hpd_bridge"; + adev->name = DRM_AUX_HPD_BRIDGE_NAME; adev->dev.parent = parent; adev->dev.release = drm_aux_hpd_bridge_release; adev->dev.platform_data = of_node_get(np); diff --git a/include/drm/bridge/aux-bridge.h b/include/drm/bridge/aux-bridge.h index c2f5a855512f..cca07a8e2d45 100644 --- a/include/drm/bridge/aux-bridge.h +++ b/include/drm/bridge/aux-bridge.h @@ -25,6 +25,7 @@ struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, str int devm_drm_dp_hpd_bridge_add(struct device *dev, struct auxiliary_device *adev); struct device *drm_dp_hpd_bridge_register(struct device *parent, struct device_node *np); +bool drm_dev_has_dp_hpd_bridge(struct device *parent, struct device_node *np); void drm_aux_hpd_bridge_notify(struct device *dev, enum drm_connector_status status); #else static inline struct auxiliary_device *devm_drm_dp_hpd_bridge_alloc(struct device *parent, @@ -44,6 +45,11 @@ static inline struct device *drm_dp_hpd_bridge_register(struct device *parent, return NULL; } +static inline bool drm_dev_has_dp_hpd_bridge(struct device *parent, struct device_node *np) +{ + return false; +} + static inline void drm_aux_hpd_bridge_notify(struct device *dev, enum drm_connector_status status) { } -- 2.53.0
