drivers/gpu/drm/sun4i/sun4i_drv.c - linux-mtk - Git at Google

 /*
  * Copyright (C) 2015 Free Electrons
  * Copyright (C) 2015 NextThing Co
  *
  * Maxime Ripard <maxime.ripard@free-electrons.com>
  *
  * 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 <linux/component.h>
 #include <linux/kfifo.h>
 #include <linux/of_graph.h>
 #include <linux/of_reserved_mem.h>

 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_of.h>

 #include "sun4i_drv.h"
 #include "sun4i_frontend.h"
 #include "sun4i_framebuffer.h"
 #include "sun4i_tcon.h"
 #include "sun8i_tcon_top.h"

 DEFINE_DRM_GEM_CMA_FOPS(sun4i_drv_fops);

 static struct drm_driver sun4i_drv_driver = {
 	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME | DRIVER_ATOMIC,

 	/* Generic Operations */
 	.lastclose		= drm_fb_helper_lastclose,
 	.fops			= &sun4i_drv_fops,
 	.name			= "sun4i-drm",
 	.desc			= "Allwinner sun4i Display Engine",
 	.date			= "20150629",
 	.major			= 1,
 	.minor			= 0,

 	/* GEM Operations */
 	.dumb_create		= drm_gem_cma_dumb_create,
 	.gem_free_object_unlocked = drm_gem_cma_free_object,
 	.gem_vm_ops		= &drm_gem_cma_vm_ops,

 	/* PRIME Operations */
 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
 	.gem_prime_import	= drm_gem_prime_import,
 	.gem_prime_export	= drm_gem_prime_export,
 	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
 	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
 	.gem_prime_vmap		= drm_gem_cma_prime_vmap,
 	.gem_prime_vunmap	= drm_gem_cma_prime_vunmap,
 	.gem_prime_mmap		= drm_gem_cma_prime_mmap,

 	/* Frame Buffer Operations */
 };

 static void sun4i_remove_framebuffers(void)
 {
 	struct apertures_struct *ap;

 	ap = alloc_apertures(1);
 	if (!ap)
 		return;

 	/* The framebuffer can be located anywhere in RAM */
 	ap->ranges[0].base = 0;
 	ap->ranges[0].size = ~0;

 	drm_fb_helper_remove_conflicting_framebuffers(ap, "sun4i-drm-fb", false);
 	kfree(ap);
 }

 static int sun4i_drv_bind(struct device *dev)
 {
 	struct drm_device *drm;
 	struct sun4i_drv *drv;
 	int ret;

 	drm = drm_dev_alloc(&sun4i_drv_driver, dev);
 	if (IS_ERR(drm))
 		return PTR_ERR(drm);

 	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
 	if (!drv) {
 		ret = -ENOMEM;
 		goto free_drm;
 	}

 	dev_set_drvdata(dev, drm);
 	drm->dev_private = drv;
 	INIT_LIST_HEAD(&drv->frontend_list);
 	INIT_LIST_HEAD(&drv->engine_list);
 	INIT_LIST_HEAD(&drv->tcon_list);

 	ret = of_reserved_mem_device_init(dev);
 	if (ret && ret != -ENODEV) {
 		dev_err(drm->dev, "Couldn't claim our memory region\n");
 		goto free_drm;
 	}

 	drm_mode_config_init(drm);

 	ret = component_bind_all(drm->dev, drm);
 	if (ret) {
 		dev_err(drm->dev, "Couldn't bind all pipelines components\n");
 		goto cleanup_mode_config;
 	}

 	/* drm_vblank_init calls kcalloc, which can fail */
 	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
 	if (ret)
 		goto cleanup_mode_config;

 	drm->irq_enabled = true;

 	/* Remove early framebuffers (ie. simplefb) */
 	sun4i_remove_framebuffers();

 	/* Create our framebuffer */
 	ret = sun4i_framebuffer_init(drm);
 	if (ret) {
 		dev_err(drm->dev, "Couldn't create our framebuffer\n");
 		goto cleanup_mode_config;
 	}

 	/* Enable connectors polling */
 	drm_kms_helper_poll_init(drm);

 	ret = drm_dev_register(drm, 0);
 	if (ret)
 		goto finish_poll;

 	return 0;

 finish_poll:
 	drm_kms_helper_poll_fini(drm);
 	sun4i_framebuffer_free(drm);
 cleanup_mode_config:
 	drm_mode_config_cleanup(drm);
 	of_reserved_mem_device_release(dev);
 free_drm:
 	drm_dev_put(drm);
 	return ret;
 }

 static void sun4i_drv_unbind(struct device *dev)
 {
 	struct drm_device *drm = dev_get_drvdata(dev);

 	drm_dev_unregister(drm);
 	drm_kms_helper_poll_fini(drm);
 	sun4i_framebuffer_free(drm);
 	drm_mode_config_cleanup(drm);

 	component_unbind_all(dev, NULL);
 	of_reserved_mem_device_release(dev);

 	drm_dev_put(drm);
 }

 static const struct component_master_ops sun4i_drv_master_ops = {
 	.bind	= sun4i_drv_bind,
 	.unbind	= sun4i_drv_unbind,
 };

 static bool sun4i_drv_node_is_connector(struct device_node *node)
 {
 	return of_device_is_compatible(node, "hdmi-connector");
 }

 static bool sun4i_drv_node_is_frontend(struct device_node *node)
 {
 	return of_device_is_compatible(node, "allwinner,sun4i-a10-display-frontend") ||
 		of_device_is_compatible(node, "allwinner,sun5i-a13-display-frontend") ||
 		of_device_is_compatible(node, "allwinner,sun6i-a31-display-frontend") ||
 		of_device_is_compatible(node, "allwinner,sun7i-a20-display-frontend") ||
 		of_device_is_compatible(node, "allwinner,sun8i-a33-display-frontend") ||
 		of_device_is_compatible(node, "allwinner,sun9i-a80-display-frontend");
 }

 static bool sun4i_drv_node_is_deu(struct device_node *node)
 {
 	return of_device_is_compatible(node, "allwinner,sun9i-a80-deu");
 }

 static bool sun4i_drv_node_is_supported_frontend(struct device_node *node)
 {
 	if (IS_ENABLED(CONFIG_DRM_SUN4I_BACKEND))
 		return !!of_match_node(sun4i_frontend_of_table, node);

 	return false;
 }

 static bool sun4i_drv_node_is_tcon(struct device_node *node)
 {
 	return !!of_match_node(sun4i_tcon_of_table, node);
 }

 static bool sun4i_drv_node_is_tcon_with_ch0(struct device_node *node)
 {
 	const struct of_device_id *match;

 	match = of_match_node(sun4i_tcon_of_table, node);
 	if (match) {
 		struct sun4i_tcon_quirks *quirks;

 		quirks = (struct sun4i_tcon_quirks *)match->data;

 		return quirks->has_channel_0;
 	}

 	return false;
 }

 static bool sun4i_drv_node_is_tcon_top(struct device_node *node)
 {
 	return IS_ENABLED(CONFIG_DRM_SUN8I_TCON_TOP) &&
 		!!of_match_node(sun8i_tcon_top_of_table, node);
 }

 static int compare_of(struct device *dev, void *data)
 {
 	DRM_DEBUG_DRIVER("Comparing of node %pOF with %pOF\n",
 			 dev->of_node,
 			 data);

 	return dev->of_node == data;
 }

 /*
  * The encoder drivers use drm_of_find_possible_crtcs to get upstream
  * crtcs from the device tree using of_graph. For the results to be
  * correct, encoders must be probed/bound after _all_ crtcs have been
  * created. The existing code uses a depth first recursive traversal
  * of the of_graph, which means the encoders downstream of the TCON
  * get add right after the first TCON. The second TCON or CRTC will
  * never be properly associated with encoders connected to it.
  *
  * Also, in a dual display pipeline setup, both frontends can feed
  * either backend, and both backends can feed either TCON, we want
  * all components of the same type to be added before the next type
  * in the pipeline. Fortunately, the pipelines are perfectly symmetric,
  * i.e. components of the same type are at the same depth when counted
  * from the frontend. The only exception is the third pipeline in
  * the A80 SoC, which we do not support anyway.
  *
  * Hence we can use a breadth first search traversal order to add
  * components. We do not need to check for duplicates. The component
  * matching system handles this for us.
  */
 struct endpoint_list {
 	DECLARE_KFIFO(fifo, struct device_node *, 16);
 };

 static void sun4i_drv_traverse_endpoints(struct endpoint_list *list,
 					 struct device_node *node,
 					 int port_id)
 {
 	struct device_node *ep, *remote, *port;

 	port = of_graph_get_port_by_id(node, port_id);
 	if (!port) {
 		DRM_DEBUG_DRIVER("No output to bind on port %d\n", port_id);
 		return;
 	}

 	for_each_available_child_of_node(port, ep) {
 		remote = of_graph_get_remote_port_parent(ep);
 		if (!remote) {
 			DRM_DEBUG_DRIVER("Error retrieving the output node\n");
 			continue;
 		}

 		if (sun4i_drv_node_is_tcon(node)) {
 			/*
 			 * TCON TOP is always probed before TCON. However, TCON
 			 * points back to TCON TOP when it is source for HDMI.
 			 * We have to skip it here to prevent infinite looping
 			 * between TCON TOP and TCON.
 			 */
 			if (sun4i_drv_node_is_tcon_top(remote)) {
 				DRM_DEBUG_DRIVER("TCON output endpoint is TCON TOP... skipping\n");
 				of_node_put(remote);
 				continue;
 			}

 			/*
 			 * If the node is our TCON with channel 0, the first
 			 * port is used for panel or bridges, and will not be
 			 * part of the component framework.
 			 */
 			if (sun4i_drv_node_is_tcon_with_ch0(node)) {
 				struct of_endpoint endpoint;

 				if (of_graph_parse_endpoint(ep, &endpoint)) {
 					DRM_DEBUG_DRIVER("Couldn't parse endpoint\n");
 					of_node_put(remote);
 					continue;
 				}

 				if (!endpoint.id) {
 					DRM_DEBUG_DRIVER("Endpoint is our panel... skipping\n");
 					of_node_put(remote);
 					continue;
 				}
 			}
 		}

 		kfifo_put(&list->fifo, remote);
 	}
 }

 static int sun4i_drv_add_endpoints(struct device *dev,
 				   struct endpoint_list *list,
 				   struct component_match **match,
 				   struct device_node *node)
 {
 	int count = 0;

 	/*
 	 * The frontend has been disabled in some of our old device
 	 * trees. If we find a node that is the frontend and is
 	 * disabled, we should just follow through and parse its
 	 * child, but without adding it to the component list.
 	 * Otherwise, we obviously want to add it to the list.
 	 */
 	if (!sun4i_drv_node_is_frontend(node) &&
 	    !of_device_is_available(node))
 		return 0;

 	/*
 	 * The connectors will be the last nodes in our pipeline, we
 	 * can just bail out.
 	 */
 	if (sun4i_drv_node_is_connector(node))
 		return 0;

 	/*
 	 * If the device is either just a regular device, or an
 	 * enabled frontend supported by the driver, we add it to our
 	 * component list.
 	 */
 	if (!(sun4i_drv_node_is_frontend(node) ||
 	      sun4i_drv_node_is_deu(node)) ||
 	    (sun4i_drv_node_is_supported_frontend(node) &&
 	     of_device_is_available(node))) {
 		/* Add current component */
 		DRM_DEBUG_DRIVER("Adding component %pOF\n", node);
 		drm_of_component_match_add(dev, match, compare_of, node);
 		count++;
 	}

 	/* each node has at least one output */
 	sun4i_drv_traverse_endpoints(list, node, 1);

 	/* TCON TOP has second and third output */
 	if (sun4i_drv_node_is_tcon_top(node)) {
 		sun4i_drv_traverse_endpoints(list, node, 3);
 		sun4i_drv_traverse_endpoints(list, node, 5);
 	}

 	return count;
 }

 static int sun4i_drv_probe(struct platform_device *pdev)
 {
 	struct component_match *match = NULL;
 	struct device_node *np = pdev->dev.of_node, *endpoint;
 	struct endpoint_list list;
 	int i, ret, count = 0;

 	INIT_KFIFO(list.fifo);

 	for (i = 0;; i++) {
 		struct device_node *pipeline = of_parse_phandle(np,
 								"allwinner,pipelines",
 								i);
 		if (!pipeline)
 			break;

 		kfifo_put(&list.fifo, pipeline);
 	}

 	while (kfifo_get(&list.fifo, &endpoint)) {
 		/* process this endpoint */
 		ret = sun4i_drv_add_endpoints(&pdev->dev, &list, &match,
 					      endpoint);

 		/* sun4i_drv_add_endpoints can fail to allocate memory */
 		if (ret < 0)
 			return ret;

 		count += ret;
 	}

 	if (count)
 		return component_master_add_with_match(&pdev->dev,
 						       &sun4i_drv_master_ops,
 						       match);
 	else
 		return 0;
 }

 static int sun4i_drv_remove(struct platform_device *pdev)
 {
 	component_master_del(&pdev->dev, &sun4i_drv_master_ops);

 	return 0;
 }

 static const struct of_device_id sun4i_drv_of_table[] = {
 	{ .compatible = "allwinner,sun4i-a10-display-engine" },
 	{ .compatible = "allwinner,sun5i-a10s-display-engine" },
 	{ .compatible = "allwinner,sun5i-a13-display-engine" },
 	{ .compatible = "allwinner,sun6i-a31-display-engine" },
 	{ .compatible = "allwinner,sun6i-a31s-display-engine" },
 	{ .compatible = "allwinner,sun7i-a20-display-engine" },
 	{ .compatible = "allwinner,sun8i-a33-display-engine" },
 	{ .compatible = "allwinner,sun8i-a83t-display-engine" },
 	{ .compatible = "allwinner,sun8i-h3-display-engine" },
 	{ .compatible = "allwinner,sun8i-v3s-display-engine" },
 	{ .compatible = "allwinner,sun9i-a80-display-engine" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sun4i_drv_of_table);

 static struct platform_driver sun4i_drv_platform_driver = {
 	.probe		= sun4i_drv_probe,
 	.remove		= sun4i_drv_remove,
 	.driver		= {
 		.name		= "sun4i-drm",
 		.of_match_table	= sun4i_drv_of_table,
 	},
 };
 module_platform_driver(sun4i_drv_platform_driver);

 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 MODULE_DESCRIPTION("Allwinner A10 Display Engine DRM/KMS Driver");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2015 Free Electrons
	* Copyright (C) 2015 NextThing Co
	*
	* Maxime Ripard <maxime.ripard@free-electrons.com>
	*
	* 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 <linux/component.h>
	#include <linux/kfifo.h>
	#include <linux/of_graph.h>
	#include <linux/of_reserved_mem.h>

	#include <drm/drmP.h>
	#include <drm/drm_crtc_helper.h>
	#include <drm/drm_fb_cma_helper.h>
	#include <drm/drm_gem_cma_helper.h>
	#include <drm/drm_fb_helper.h>
	#include <drm/drm_of.h>

	#include "sun4i_drv.h"
	#include "sun4i_frontend.h"
	#include "sun4i_framebuffer.h"
	#include "sun4i_tcon.h"
	#include "sun8i_tcon_top.h"

	DEFINE_DRM_GEM_CMA_FOPS(sun4i_drv_fops);

	static struct drm_driver sun4i_drv_driver = {
	.driver_features = DRIVER_GEM \| DRIVER_MODESET \| DRIVER_PRIME \| DRIVER_ATOMIC,

	/* Generic Operations */
	.lastclose = drm_fb_helper_lastclose,
	.fops = &sun4i_drv_fops,
	.name = "sun4i-drm",
	.desc = "Allwinner sun4i Display Engine",
	.date = "20150629",
	.major = 1,
	.minor = 0,

	/* GEM Operations */
	.dumb_create = drm_gem_cma_dumb_create,
	.gem_free_object_unlocked = drm_gem_cma_free_object,
	.gem_vm_ops = &drm_gem_cma_vm_ops,

	/* PRIME Operations */
	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
	.gem_prime_import = drm_gem_prime_import,
	.gem_prime_export = drm_gem_prime_export,
	.gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
	.gem_prime_vmap = drm_gem_cma_prime_vmap,
	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
	.gem_prime_mmap = drm_gem_cma_prime_mmap,

	/* Frame Buffer Operations */
	};

	static void sun4i_remove_framebuffers(void)
	{
	struct apertures_struct *ap;

	ap = alloc_apertures(1);
	if (!ap)
	return;

	/* The framebuffer can be located anywhere in RAM */
	ap->ranges[0].base = 0;
	ap->ranges[0].size = ~0;

	drm_fb_helper_remove_conflicting_framebuffers(ap, "sun4i-drm-fb", false);
	kfree(ap);
	}

	static int sun4i_drv_bind(struct device *dev)
	{
	struct drm_device *drm;
	struct sun4i_drv *drv;
	int ret;

	drm = drm_dev_alloc(&sun4i_drv_driver, dev);
	if (IS_ERR(drm))
	return PTR_ERR(drm);

	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
	if (!drv) {
	ret = -ENOMEM;
	goto free_drm;
	}

	dev_set_drvdata(dev, drm);
	drm->dev_private = drv;
	INIT_LIST_HEAD(&drv->frontend_list);
	INIT_LIST_HEAD(&drv->engine_list);
	INIT_LIST_HEAD(&drv->tcon_list);

	ret = of_reserved_mem_device_init(dev);
	if (ret && ret != -ENODEV) {
	dev_err(drm->dev, "Couldn't claim our memory region\n");
	goto free_drm;
	}

	drm_mode_config_init(drm);

	ret = component_bind_all(drm->dev, drm);
	if (ret) {
	dev_err(drm->dev, "Couldn't bind all pipelines components\n");
	goto cleanup_mode_config;
	}

	/* drm_vblank_init calls kcalloc, which can fail */
	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
	if (ret)
	goto cleanup_mode_config;

	drm->irq_enabled = true;

	/* Remove early framebuffers (ie. simplefb) */
	sun4i_remove_framebuffers();

	/* Create our framebuffer */
	ret = sun4i_framebuffer_init(drm);
	if (ret) {
	dev_err(drm->dev, "Couldn't create our framebuffer\n");
	goto cleanup_mode_config;
	}

	/* Enable connectors polling */
	drm_kms_helper_poll_init(drm);

	ret = drm_dev_register(drm, 0);
	if (ret)
	goto finish_poll;

	return 0;

	finish_poll:
	drm_kms_helper_poll_fini(drm);
	sun4i_framebuffer_free(drm);
	cleanup_mode_config:
	drm_mode_config_cleanup(drm);
	of_reserved_mem_device_release(dev);
	free_drm:
	drm_dev_put(drm);
	return ret;
	}

	static void sun4i_drv_unbind(struct device *dev)
	{
	struct drm_device *drm = dev_get_drvdata(dev);

	drm_dev_unregister(drm);
	drm_kms_helper_poll_fini(drm);
	sun4i_framebuffer_free(drm);
	drm_mode_config_cleanup(drm);

	component_unbind_all(dev, NULL);
	of_reserved_mem_device_release(dev);

	drm_dev_put(drm);
	}

	static const struct component_master_ops sun4i_drv_master_ops = {
	.bind = sun4i_drv_bind,
	.unbind = sun4i_drv_unbind,
	};

	static bool sun4i_drv_node_is_connector(struct device_node *node)
	{
	return of_device_is_compatible(node, "hdmi-connector");
	}

	static bool sun4i_drv_node_is_frontend(struct device_node *node)
	{
	return of_device_is_compatible(node, "allwinner,sun4i-a10-display-frontend") \|\|
	of_device_is_compatible(node, "allwinner,sun5i-a13-display-frontend") \|\|
	of_device_is_compatible(node, "allwinner,sun6i-a31-display-frontend") \|\|
	of_device_is_compatible(node, "allwinner,sun7i-a20-display-frontend") \|\|
	of_device_is_compatible(node, "allwinner,sun8i-a33-display-frontend") \|\|
	of_device_is_compatible(node, "allwinner,sun9i-a80-display-frontend");
	}

	static bool sun4i_drv_node_is_deu(struct device_node *node)
	{
	return of_device_is_compatible(node, "allwinner,sun9i-a80-deu");
	}

	static bool sun4i_drv_node_is_supported_frontend(struct device_node *node)
	{
	if (IS_ENABLED(CONFIG_DRM_SUN4I_BACKEND))
	return !!of_match_node(sun4i_frontend_of_table, node);

	return false;
	}

	static bool sun4i_drv_node_is_tcon(struct device_node *node)
	{
	return !!of_match_node(sun4i_tcon_of_table, node);
	}

	static bool sun4i_drv_node_is_tcon_with_ch0(struct device_node *node)
	{
	const struct of_device_id *match;

	match = of_match_node(sun4i_tcon_of_table, node);
	if (match) {
	struct sun4i_tcon_quirks *quirks;

	quirks = (struct sun4i_tcon_quirks *)match->data;

	return quirks->has_channel_0;
	}

	return false;
	}

	static bool sun4i_drv_node_is_tcon_top(struct device_node *node)
	{
	return IS_ENABLED(CONFIG_DRM_SUN8I_TCON_TOP) &&
	!!of_match_node(sun8i_tcon_top_of_table, node);
	}

	static int compare_of(struct device dev, void data)
	{
	DRM_DEBUG_DRIVER("Comparing of node %pOF with %pOF\n",
	dev->of_node,
	data);

	return dev->of_node == data;
	}

	/*
	* The encoder drivers use drm_of_find_possible_crtcs to get upstream
	* crtcs from the device tree using of_graph. For the results to be
	* correct, encoders must be probed/bound after _all_ crtcs have been
	* created. The existing code uses a depth first recursive traversal
	* of the of_graph, which means the encoders downstream of the TCON
	* get add right after the first TCON. The second TCON or CRTC will
	* never be properly associated with encoders connected to it.
	*
	* Also, in a dual display pipeline setup, both frontends can feed
	* either backend, and both backends can feed either TCON, we want
	* all components of the same type to be added before the next type
	* in the pipeline. Fortunately, the pipelines are perfectly symmetric,
	* i.e. components of the same type are at the same depth when counted
	* from the frontend. The only exception is the third pipeline in
	* the A80 SoC, which we do not support anyway.
	*
	* Hence we can use a breadth first search traversal order to add
	* components. We do not need to check for duplicates. The component
	* matching system handles this for us.
	*/
	struct endpoint_list {
	DECLARE_KFIFO(fifo, struct device_node *, 16);
	};

	static void sun4i_drv_traverse_endpoints(struct endpoint_list *list,
	struct device_node *node,
	int port_id)
	{
	struct device_node ep, remote, *port;

	port = of_graph_get_port_by_id(node, port_id);
	if (!port) {
	DRM_DEBUG_DRIVER("No output to bind on port %d\n", port_id);
	return;
	}

	for_each_available_child_of_node(port, ep) {
	remote = of_graph_get_remote_port_parent(ep);
	if (!remote) {
	DRM_DEBUG_DRIVER("Error retrieving the output node\n");
	continue;
	}

	if (sun4i_drv_node_is_tcon(node)) {
	/*
	* TCON TOP is always probed before TCON. However, TCON
	* points back to TCON TOP when it is source for HDMI.
	* We have to skip it here to prevent infinite looping
	* between TCON TOP and TCON.
	*/
	if (sun4i_drv_node_is_tcon_top(remote)) {
	DRM_DEBUG_DRIVER("TCON output endpoint is TCON TOP... skipping\n");
	of_node_put(remote);
	continue;
	}

	/*
	* If the node is our TCON with channel 0, the first
	* port is used for panel or bridges, and will not be
	* part of the component framework.
	*/
	if (sun4i_drv_node_is_tcon_with_ch0(node)) {
	struct of_endpoint endpoint;

	if (of_graph_parse_endpoint(ep, &endpoint)) {
	DRM_DEBUG_DRIVER("Couldn't parse endpoint\n");
	of_node_put(remote);
	continue;
	}

	if (!endpoint.id) {
	DRM_DEBUG_DRIVER("Endpoint is our panel... skipping\n");
	of_node_put(remote);
	continue;
	}
	}
	}

	kfifo_put(&list->fifo, remote);
	}
	}

	static int sun4i_drv_add_endpoints(struct device *dev,
	struct endpoint_list *list,
	struct component_match **match,
	struct device_node *node)
	{
	int count = 0;

	/*
	* The frontend has been disabled in some of our old device
	* trees. If we find a node that is the frontend and is
	* disabled, we should just follow through and parse its
	* child, but without adding it to the component list.
	* Otherwise, we obviously want to add it to the list.
	*/
	if (!sun4i_drv_node_is_frontend(node) &&
	!of_device_is_available(node))
	return 0;

	/*
	* The connectors will be the last nodes in our pipeline, we
	* can just bail out.
	*/
	if (sun4i_drv_node_is_connector(node))
	return 0;

	/*
	* If the device is either just a regular device, or an
	* enabled frontend supported by the driver, we add it to our
	* component list.
	*/
	if (!(sun4i_drv_node_is_frontend(node) \|\|
	sun4i_drv_node_is_deu(node)) \|\|
	(sun4i_drv_node_is_supported_frontend(node) &&
	of_device_is_available(node))) {
	/* Add current component */
	DRM_DEBUG_DRIVER("Adding component %pOF\n", node);
	drm_of_component_match_add(dev, match, compare_of, node);
	count++;
	}

	/* each node has at least one output */
	sun4i_drv_traverse_endpoints(list, node, 1);

	/* TCON TOP has second and third output */
	if (sun4i_drv_node_is_tcon_top(node)) {
	sun4i_drv_traverse_endpoints(list, node, 3);
	sun4i_drv_traverse_endpoints(list, node, 5);
	}

	return count;
	}

	static int sun4i_drv_probe(struct platform_device *pdev)
	{
	struct component_match *match = NULL;
	struct device_node np = pdev->dev.of_node, endpoint;
	struct endpoint_list list;
	int i, ret, count = 0;

	INIT_KFIFO(list.fifo);

	for (i = 0;; i++) {
	struct device_node *pipeline = of_parse_phandle(np,
	"allwinner,pipelines",
	i);
	if (!pipeline)
	break;

	kfifo_put(&list.fifo, pipeline);
	}

	while (kfifo_get(&list.fifo, &endpoint)) {
	/* process this endpoint */
	ret = sun4i_drv_add_endpoints(&pdev->dev, &list, &match,
	endpoint);

	/* sun4i_drv_add_endpoints can fail to allocate memory */
	if (ret < 0)
	return ret;

	count += ret;
	}

	if (count)
	return component_master_add_with_match(&pdev->dev,
	&sun4i_drv_master_ops,
	match);
	else
	return 0;
	}

	static int sun4i_drv_remove(struct platform_device *pdev)
	{
	component_master_del(&pdev->dev, &sun4i_drv_master_ops);

	return 0;
	}

	static const struct of_device_id sun4i_drv_of_table[] = {
	{ .compatible = "allwinner,sun4i-a10-display-engine" },
	{ .compatible = "allwinner,sun5i-a10s-display-engine" },
	{ .compatible = "allwinner,sun5i-a13-display-engine" },
	{ .compatible = "allwinner,sun6i-a31-display-engine" },
	{ .compatible = "allwinner,sun6i-a31s-display-engine" },
	{ .compatible = "allwinner,sun7i-a20-display-engine" },
	{ .compatible = "allwinner,sun8i-a33-display-engine" },
	{ .compatible = "allwinner,sun8i-a83t-display-engine" },
	{ .compatible = "allwinner,sun8i-h3-display-engine" },
	{ .compatible = "allwinner,sun8i-v3s-display-engine" },
	{ .compatible = "allwinner,sun9i-a80-display-engine" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, sun4i_drv_of_table);

	static struct platform_driver sun4i_drv_platform_driver = {
	.probe = sun4i_drv_probe,
	.remove = sun4i_drv_remove,
	.driver = {
	.name = "sun4i-drm",
	.of_match_table = sun4i_drv_of_table,
	},
	};
	module_platform_driver(sun4i_drv_platform_driver);

	MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
	MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
	MODULE_DESCRIPTION("Allwinner A10 Display Engine DRM/KMS Driver");
	MODULE_LICENSE("GPL");