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Commit 13dfc054 authored by Eric Anholt's avatar Eric Anholt Committed by Archit Taneja
Browse files

drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge. 



Many DRM drivers have common code to make a stub connector
implementation that wraps a drm_panel.  By wrapping the panel in a DRM
bridge, all of the connector code (including calls during encoder
enable/disable) goes away.

v2: Fix build with CONFIG_DRM=m, drop "dev" argument that should just
    be the panel's dev, move kerneldoc up a level and document
    _remove().
v3: Fix another breakage with CONFIG_DRM=m, fix breakage with
    CONFIG_OF=n, move protos under CONFIG_DRM_PANEL_BRIDGE, wrap a
    line.

Signed-off-by: default avatarEric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v1)
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> (v2)
Acked-by: Archit Taneja <architt@codeaurora.org> (v2)
Signed-off-by: default avatarArchit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170602202514.11900-1-eric@anholt.net
parent b0febde7

Documentation/gpu/drm-kms-helpers.rst

+6 −0
Original line number Diff line number Diff line
@@ -143,6 +143,12 @@ Bridge Helper Reference 
.. kernel-doc:: drivers/gpu/drm/drm_bridge.c

   :export:



Panel-Bridge Helper Reference

-----------------------------



.. kernel-doc:: drivers/gpu/drm/bridge/panel.c

   :export:



.. _drm_panel_helper:



Panel Helper Reference

drivers/gpu/drm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o 
drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o

drm-$(CONFIG_PCI) += ati_pcigart.o

drm-$(CONFIG_DRM_PANEL) += drm_panel.o

drm-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o

drm-$(CONFIG_OF) += drm_of.o

drm-$(CONFIG_AGP) += drm_agpsupport.o

drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o

drivers/gpu/drm/bridge/Kconfig

+9 −2
Original line number Diff line number Diff line
@@ -4,6 +4,14 @@ config DRM_BRIDGE 
	help

	  Bridge registration and lookup framework.



config DRM_PANEL_BRIDGE

	def_bool y

	depends on DRM_BRIDGE

	depends on DRM_KMS_HELPER

	select DRM_PANEL

	help

	  DRM bridge wrapper of DRM panels



menu "Display Interface Bridges"

	depends on DRM && DRM_BRIDGE
@@ -27,8 +35,7 @@ config DRM_DUMB_VGA_DAC 
config DRM_LVDS_ENCODER

	tristate "Transparent parallel to LVDS encoder support"

	depends on OF

	select DRM_KMS_HELPER

	select DRM_PANEL

	select DRM_PANEL_BRIDGE

	help

	  Support for transparent parallel to LVDS encoders that don't require

	  any configuration.

drivers/gpu/drm/bridge/lvds-encoder.c

+18 −139
Original line number Diff line number Diff line
@@ -8,144 +8,18 @@ 
 */



#include <drm/drmP.h>

#include <drm/drm_atomic_helper.h>

#include <drm/drm_connector.h>

#include <drm/drm_crtc_helper.h>

#include <drm/drm_encoder.h>

#include <drm/drm_modeset_helper_vtables.h>

#include <drm/drm_bridge.h>

#include <drm/drm_panel.h>



#include <linux/of_graph.h>



struct lvds_encoder {

	struct device *dev;



	struct drm_bridge bridge;

	struct drm_connector connector;

	struct drm_panel *panel;

};



static inline struct lvds_encoder *

drm_bridge_to_lvds_encoder(struct drm_bridge *bridge)

{

	return container_of(bridge, struct lvds_encoder, bridge);

}



static inline struct lvds_encoder *

drm_connector_to_lvds_encoder(struct drm_connector *connector)

{

	return container_of(connector, struct lvds_encoder, connector);

}



static int lvds_connector_get_modes(struct drm_connector *connector)

{

	struct lvds_encoder *lvds = drm_connector_to_lvds_encoder(connector);



	return drm_panel_get_modes(lvds->panel);

}



static const struct drm_connector_helper_funcs lvds_connector_helper_funcs = {

	.get_modes = lvds_connector_get_modes,

};



static const struct drm_connector_funcs lvds_connector_funcs = {

	.dpms = drm_atomic_helper_connector_dpms,

	.reset = drm_atomic_helper_connector_reset,

	.fill_modes = drm_helper_probe_single_connector_modes,

	.destroy = drm_connector_cleanup,

	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,

	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,

};



static int lvds_encoder_attach(struct drm_bridge *bridge)

{

	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);

	struct drm_connector *connector = &lvds->connector;

	int ret;



	if (!bridge->encoder) {

		DRM_ERROR("Missing encoder\n");

		return -ENODEV;

	}



	drm_connector_helper_add(connector, &lvds_connector_helper_funcs);



	ret = drm_connector_init(bridge->dev, connector, &lvds_connector_funcs,

				 DRM_MODE_CONNECTOR_LVDS);

	if (ret) {

		DRM_ERROR("Failed to initialize connector\n");

		return ret;

	}



	drm_mode_connector_attach_encoder(&lvds->connector, bridge->encoder);



	ret = drm_panel_attach(lvds->panel, &lvds->connector);

	if (ret < 0)

		return ret;



	return 0;

}



static void lvds_encoder_detach(struct drm_bridge *bridge)

{

	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);



	drm_panel_detach(lvds->panel);

}



static void lvds_encoder_pre_enable(struct drm_bridge *bridge)

{

	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);



	drm_panel_prepare(lvds->panel);

}



static void lvds_encoder_enable(struct drm_bridge *bridge)

{

	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);



	drm_panel_enable(lvds->panel);

}



static void lvds_encoder_disable(struct drm_bridge *bridge)

{

	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);



	drm_panel_disable(lvds->panel);

}



static void lvds_encoder_post_disable(struct drm_bridge *bridge)

{

	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);



	drm_panel_unprepare(lvds->panel);

}



static const struct drm_bridge_funcs lvds_encoder_bridge_funcs = {

	.attach = lvds_encoder_attach,

	.detach = lvds_encoder_detach,

	.pre_enable = lvds_encoder_pre_enable,

	.enable = lvds_encoder_enable,

	.disable = lvds_encoder_disable,

	.post_disable = lvds_encoder_post_disable,

};



static int lvds_encoder_probe(struct platform_device *pdev)

{

	struct lvds_encoder *lvds;

	struct device_node *port;

	struct device_node *endpoint;

	struct device_node *panel;



	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);

	if (!lvds)

		return -ENOMEM;



	lvds->dev = &pdev->dev;

	platform_set_drvdata(pdev, lvds);



	lvds->bridge.funcs = &lvds_encoder_bridge_funcs;

	lvds->bridge.of_node = pdev->dev.of_node;

	struct device_node *panel_node;

	struct drm_panel *panel;

	struct drm_bridge *bridge;



	/* Locate the panel DT node. */

	port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
@@ -161,29 +35,34 @@ static int lvds_encoder_probe(struct platform_device *pdev) 
		return -ENXIO;

	}



	panel = of_graph_get_remote_port_parent(endpoint);

	panel_node = of_graph_get_remote_port_parent(endpoint);

	of_node_put(endpoint);

	if (!panel) {

	if (!panel_node) {

		dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");

		return -ENXIO;

	}



	lvds->panel = of_drm_find_panel(panel);

	of_node_put(panel);

	if (!lvds->panel) {

	panel = of_drm_find_panel(panel_node);

	of_node_put(panel_node);

	if (!panel) {

		dev_dbg(&pdev->dev, "panel not found, deferring probe\n");

		return -EPROBE_DEFER;

	}



	/* Register the bridge. */

	return drm_bridge_add(&lvds->bridge);

	bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);

	if (IS_ERR(bridge))

		return PTR_ERR(bridge);



	platform_set_drvdata(pdev, bridge);



	return 0;

}



static int lvds_encoder_remove(struct platform_device *pdev)

{

	struct lvds_encoder *encoder = platform_get_drvdata(pdev);

	struct drm_bridge *bridge = platform_get_drvdata(pdev);



	drm_bridge_remove(&encoder->bridge);

	drm_bridge_remove(bridge);



	return 0;

}

drivers/gpu/drm/bridge/panel.c

0 → 100644
+200 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>

 * Copyright (C) 2017 Broadcom

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 of

 * the License, or (at your option) any later version.

 */



#include <drm/drmP.h>

#include <drm/drm_panel.h>

#include <drm/drm_atomic_helper.h>

#include <drm/drm_connector.h>

#include <drm/drm_crtc_helper.h>

#include <drm/drm_encoder.h>

#include <drm/drm_modeset_helper_vtables.h>

#include <drm/drm_panel.h>



struct panel_bridge {

	struct drm_bridge bridge;

	struct drm_connector connector;

	struct drm_panel *panel;

	u32 connector_type;

};



static inline struct panel_bridge *

drm_bridge_to_panel_bridge(struct drm_bridge *bridge)

{

	return container_of(bridge, struct panel_bridge, bridge);

}



static inline struct panel_bridge *

drm_connector_to_panel_bridge(struct drm_connector *connector)

{

	return container_of(connector, struct panel_bridge, connector);

}



static int panel_bridge_connector_get_modes(struct drm_connector *connector)

{

	struct panel_bridge *panel_bridge =

		drm_connector_to_panel_bridge(connector);



	return drm_panel_get_modes(panel_bridge->panel);

}



static const struct drm_connector_helper_funcs

panel_bridge_connector_helper_funcs = {

	.get_modes = panel_bridge_connector_get_modes,

};



static const struct drm_connector_funcs panel_bridge_connector_funcs = {

	.dpms = drm_atomic_helper_connector_dpms,

	.reset = drm_atomic_helper_connector_reset,

	.fill_modes = drm_helper_probe_single_connector_modes,

	.destroy = drm_connector_cleanup,

	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,

	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,

};



static int panel_bridge_attach(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);

	struct drm_connector *connector = &panel_bridge->connector;

	int ret;



	if (!bridge->encoder) {

		DRM_ERROR("Missing encoder\n");

		return -ENODEV;

	}



	drm_connector_helper_add(connector,

				 &panel_bridge_connector_helper_funcs);



	ret = drm_connector_init(bridge->dev, connector,

				 &panel_bridge_connector_funcs,

				 panel_bridge->connector_type);

	if (ret) {

		DRM_ERROR("Failed to initialize connector\n");

		return ret;

	}



	drm_mode_connector_attach_encoder(&panel_bridge->connector,

					  bridge->encoder);



	ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);

	if (ret < 0)

		return ret;



	return 0;

}



static void panel_bridge_detach(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);



	drm_panel_detach(panel_bridge->panel);

}



static void panel_bridge_pre_enable(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);



	drm_panel_prepare(panel_bridge->panel);

}



static void panel_bridge_enable(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);



	drm_panel_enable(panel_bridge->panel);

}



static void panel_bridge_disable(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);



	drm_panel_disable(panel_bridge->panel);

}



static void panel_bridge_post_disable(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);



	drm_panel_unprepare(panel_bridge->panel);

}



static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {

	.attach = panel_bridge_attach,

	.detach = panel_bridge_detach,

	.pre_enable = panel_bridge_pre_enable,

	.enable = panel_bridge_enable,

	.disable = panel_bridge_disable,

	.post_disable = panel_bridge_post_disable,

};



/**

 * drm_panel_bridge_add - Creates a drm_bridge and drm_connector that

 * just calls the appropriate functions from drm_panel.

 *

 * @panel: The drm_panel being wrapped.  Must be non-NULL.

 * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be

 * created.

 *

 * For drivers converting from directly using drm_panel: The expected

 * usage pattern is that during either encoder module probe or DSI

 * host attach, a drm_panel will be looked up through

 * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to

 * wrap that panel in the new bridge, and the result can then be

 * passed to drm_bridge_attach().  The drm_panel_prepare() and related

 * functions can be dropped from the encoder driver (they're now

 * called by the KMS helpers before calling into the encoder), along

 * with connector creation.  When done with the bridge,

 * drm_bridge_detach() should be called as normal, then

 * drm_panel_bridge_remove() to free it.

 */

struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,

					u32 connector_type)

{

	struct panel_bridge *panel_bridge;

	int ret;



	if (!panel)

		return ERR_PTR(EINVAL);



	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),

				    GFP_KERNEL);

	if (!panel_bridge)

		return ERR_PTR(-ENOMEM);



	panel_bridge->connector_type = connector_type;

	panel_bridge->panel = panel;



	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;

#ifdef CONFIG_OF

	panel_bridge->bridge.of_node = panel->dev->of_node;

#endif



	ret = drm_bridge_add(&panel_bridge->bridge);

	if (ret)

		return ERR_PTR(ret);



	return &panel_bridge->bridge;

}

EXPORT_SYMBOL(drm_panel_bridge_add);



/**

 * drm_panel_bridge_remove - Unregisters and frees a drm_bridge

 * created by drm_panel_bridge_add().

 *

 * @bridge: The drm_bridge being freed.

 */

void drm_panel_bridge_remove(struct drm_bridge *bridge)

{

	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);



	drm_bridge_remove(bridge);

	devm_kfree(panel_bridge->panel->dev, bridge);

}

EXPORT_SYMBOL(drm_panel_bridge_remove);