Unverified Commit 87ea9580 authored by Maxime Ripard's avatar Maxime Ripard
Browse files

drm/bridge: Add a function to abstract away panels 



Display drivers so far need to have a lot of boilerplate to first
retrieve either the panel or bridge that they are connected to using
drm_of_find_panel_or_bridge(), and then either deal with each with ad-hoc
functions or create a drm panel bridge through drm_panel_bridge_add.

In order to reduce the boilerplate and hopefully create a path of least
resistance towards using the DRM panel bridge layer, let's create the
function devm_drm_of_get_bridge() to reduce that boilerplate.

Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
Reviewed-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210910130941.1740182-2-maxime@cerno.tech
parent 2f765205

drivers/gpu/drm/drm_bridge.c

+37 −4
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <drm/drm_atomic_state_helper.h>

#include <drm/drm_bridge.h>

#include <drm/drm_encoder.h>

#include <drm/drm_of.h>

#include <drm/drm_print.h>



#include "drm_crtc_internal.h"
@@ -51,10 +52,8 @@ 
 *

 * Display drivers are responsible for linking encoders with the first bridge

 * in the chains. This is done by acquiring the appropriate bridge with

 * of_drm_find_bridge() or drm_of_find_panel_or_bridge(), or creating it for a

 * panel with drm_panel_bridge_add_typed() (or the managed version

 * devm_drm_panel_bridge_add_typed()). Once acquired, the bridge shall be

 * attached to the encoder with a call to drm_bridge_attach().

 * devm_drm_of_get_bridge(). Once acquired, the bridge shall be attached to the

 * encoder with a call to drm_bridge_attach().

 *

 * Bridges are responsible for linking themselves with the next bridge in the

 * chain, if any. This is done the same way as for encoders, with the call to
@@ -1233,6 +1232,40 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np) 
	return NULL;

}

EXPORT_SYMBOL(of_drm_find_bridge);



/**

 * devm_drm_of_get_bridge - Return next bridge in the chain

 * @dev: device to tie the bridge lifetime to

 * @np: device tree node containing encoder output ports

 * @port: port in the device tree node

 * @endpoint: endpoint in the device tree node

 *

 * Given a DT node's port and endpoint number, finds the connected node

 * and returns the associated bridge if any, or creates and returns a

 * drm panel bridge instance if a panel is connected.

 *

 * Returns a pointer to the bridge if successful, or an error pointer

 * otherwise.

 */

struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,

					  struct device_node *np,

					  u32 port, u32 endpoint)

{

	struct drm_bridge *bridge;

	struct drm_panel *panel;

	int ret;



	ret = drm_of_find_panel_or_bridge(np, port, endpoint,

					  &panel, &bridge);

	if (ret)

		return ERR_PTR(ret);



	if (panel)

		bridge = devm_drm_panel_bridge_add(dev, panel);



	return bridge;

}

EXPORT_SYMBOL(devm_drm_of_get_bridge);

#endif



MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");

drivers/gpu/drm/drm_of.c

+3 −0
Original line number Diff line number Diff line
@@ -231,6 +231,9 @@ EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); 
 * return either the associated struct drm_panel or drm_bridge device. Either

 * @panel or @bridge must not be NULL.

 *

 * This function is deprecated and should not be used in new drivers. Use

 * devm_drm_of_get_bridge() instead.

 *

 * Returns zero if successful, or one of the standard error codes if it fails.

 */

int drm_of_find_panel_or_bridge(const struct device_node *np,

include/drm/drm_bridge.h

+2 −0
Original line number Diff line number Diff line
@@ -911,6 +911,8 @@ struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev, 
struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,

						   struct drm_panel *panel,

						   u32 connector_type);

struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,

					  u32 port, u32 endpoint);

struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);

#endif