From 04fcddac28c9f28239f40c9b90e3e76ed5f5cb13 Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Thu, 3 Apr 2025 09:39:03 +0200 Subject: dm: core: Add a helper to retrieve devices through graph endpoints There are already several helpers to find a udevice based on its position in a device tree, like getting a child or a node pointed by a phandle, but there was no support for graph endpoints, which are very common in display pipelines. Add a new helper, named uclass_get_device_by_endpoint() which enters the child graph reprensentation, looks for a specific port, then follows the remote endpoint, and finally retrieves the first parent of the given uclass_id. This is a very handy and straightforward way to get a bridge or a panel handle. Reviewed-by: Simon Glass Signed-off-by: Miquel Raynal --- include/dm/uclass.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'include') diff --git a/include/dm/uclass.h b/include/dm/uclass.h index c2793040923..8fdd7272511 100644 --- a/include/dm/uclass.h +++ b/include/dm/uclass.h @@ -333,6 +333,30 @@ int uclass_get_device_by_phandle(enum uclass_id id, struct udevice *parent, int uclass_get_device_by_driver(enum uclass_id id, const struct driver *drv, struct udevice **devp); +/** + * uclass_get_device_by_endpoint() - Get a uclass device for a remote endpoint + * + * This searches through the parents of the specified remote endpoint + * for the first device matching the uclass. Said otherwise, this helper + * goes through the graph (endpoint) representation and searches for + * matching devices. Endpoints can be subnodes of the "port" node or + * subnodes of ports identified with a reg property, themselves in a + * "ports" container. + * + * The device is probed to activate it ready for use. + * + * @class_id: uclass ID to look up + * @dev: Device to start from + * @port_idx: Index of the port to follow, -1 if there is a single 'port' + * node without reg. + * @ep_idx: Index of the endpoint to follow, -1 if there is a single 'endpoint' + * node without reg. + * @target: Returns pointer to the first device matching the expected uclass. + * Return: 0 if OK, -ve on error + */ +int uclass_get_device_by_endpoint(enum uclass_id class_id, struct udevice *dev, + int port_idx, int ep_idx, struct udevice **target); + /** * uclass_first_device() - Get the first device in a uclass * -- cgit v1.2.3