drivers/gpu/drm/pl111/pl111_drv.c - third_party/linux - Git at Google

 /*
  * (C) COPYRIGHT 2012-2013 ARM Limited. All rights reserved.
  *
  * Parts of this file were based on sources as follows:
  *
  * Copyright (c) 2006-2008 Intel Corporation
  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
  * Copyright (C) 2011 Texas Instruments
  *
  * This program is free software and is provided to you under the terms of the
  * GNU General Public License version 2 as published by the Free Software
  * Foundation, and any use by you of this program is subject to the terms of
  * such GNU licence.
  *
  */

 /**
  * DOC: ARM PrimeCell PL111 CLCD Driver
  *
  * The PL111 is a simple LCD controller that can support TFT and STN
  * displays.  This driver exposes a standard KMS interface for them.
  *
  * This driver uses the same Device Tree binding as the fbdev CLCD
  * driver.  While the fbdev driver supports panels that may be
  * connected to the CLCD internally to the CLCD driver, in DRM the
  * panels get split out to drivers/gpu/drm/panels/.  This means that,
  * in converting from using fbdev to using DRM, you also need to write
  * a panel driver (which may be as simple as an entry in
  * panel-simple.c).
  *
  * The driver currently doesn't expose the cursor.  The DRM API for
  * cursors requires support for 64x64 ARGB8888 cursor images, while
  * the hardware can only support 64x64 monochrome with masking
  * cursors.  While one could imagine trying to hack something together
  * to look at the ARGB8888 and program reasonable in monochrome, we
  * just don't expose the cursor at all instead, and leave cursor
  * support to the X11 software cursor layer.
  *
  * TODO:
  *
  * - Fix race between setting plane base address and getting IRQ for
  *   vsync firing the pageflip completion.
  *
  * - Use the "max-memory-bandwidth" DT property to filter the
  *   supported formats.
  *
  * - Read back hardware state at boot to skip reprogramming the
  *   hardware when doing a no-op modeset.
  *
  * - Use the CLKSEL bit to support switching between the two external
  *   clock parents.
  */

 #include <linux/amba/bus.h>
 #include <linux/amba/clcd-regs.h>
 #include <linux/version.h>
 #include <linux/shmem_fs.h>
 #include <linux/dma-buf.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_graph.h>
 #include <linux/of_reserved_mem.h>

 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_of.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_panel.h>

 #include "pl111_drm.h"
 #include "pl111_versatile.h"

 #define DRIVER_DESC      "DRM module for PL111"

 static const struct drm_mode_config_funcs mode_config_funcs = {
 	.fb_create = drm_gem_fb_create,
 	.atomic_check = drm_atomic_helper_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };

 static int pl111_modeset_init(struct drm_device *dev)
 {
 	struct drm_mode_config *mode_config;
 	struct pl111_drm_dev_private *priv = dev->dev_private;
 	struct device_node *np = dev->dev->of_node;
 	struct device_node *remote;
 	struct drm_panel *panel = NULL;
 	struct drm_bridge *bridge = NULL;
 	bool defer = false;
 	int ret = 0;
 	int i;

 	drm_mode_config_init(dev);
 	mode_config = &dev->mode_config;
 	mode_config->funcs = &mode_config_funcs;
 	mode_config->min_width = 1;
 	mode_config->max_width = 1024;
 	mode_config->min_height = 1;
 	mode_config->max_height = 768;

 	i = 0;
 	for_each_endpoint_of_node(np, remote) {
 		struct drm_panel *tmp_panel;
 		struct drm_bridge *tmp_bridge;

 		dev_dbg(dev->dev, "checking endpoint %d\n", i);

 		ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
 						  0, i,
 						  &tmp_panel,
 						  &tmp_bridge);
 		if (ret) {
 			if (ret == -EPROBE_DEFER) {
 				/*
 				 * Something deferred, but that is often just
 				 * another way of saying -ENODEV, but let's
 				 * cast a vote for later deferral.
 				 */
 				defer = true;
 			} else if (ret != -ENODEV) {
 				/* Continue, maybe something else is working */
 				dev_err(dev->dev,
 					"endpoint %d returns %d\n", i, ret);
 			}
 		}

 		if (tmp_panel) {
 			dev_info(dev->dev,
 				 "found panel on endpoint %d\n", i);
 			panel = tmp_panel;
 		}
 		if (tmp_bridge) {
 			dev_info(dev->dev,
 				 "found bridge on endpoint %d\n", i);
 			bridge = tmp_bridge;
 		}

 		i++;
 	}

 	/*
 	 * If we can't find neither panel nor bridge on any of the
 	 * endpoints, and any of them retured -EPROBE_DEFER, then
 	 * let's defer this driver too.
 	 */
 	if ((!panel && !bridge) && defer)
 		return -EPROBE_DEFER;

 	if (panel) {
 		bridge = drm_panel_bridge_add(panel,
 					      DRM_MODE_CONNECTOR_Unknown);
 		if (IS_ERR(bridge)) {
 			ret = PTR_ERR(bridge);
 			goto out_config;
 		}
 	} else if (bridge) {
 		dev_info(dev->dev, "Using non-panel bridge\n");
 	} else {
 		dev_err(dev->dev, "No bridge, exiting\n");
 		return -ENODEV;
 	}

 	priv->bridge = bridge;
 	if (panel) {
 		priv->panel = panel;
 		priv->connector = panel->connector;
 	}

 	ret = pl111_display_init(dev);
 	if (ret != 0) {
 		dev_err(dev->dev, "Failed to init display\n");
 		goto out_bridge;
 	}

 	ret = drm_simple_display_pipe_attach_bridge(&priv->pipe,
 						    bridge);
 	if (ret)
 		return ret;

 	if (!priv->variant->broken_vblank) {
 		ret = drm_vblank_init(dev, 1);
 		if (ret != 0) {
 			dev_err(dev->dev, "Failed to init vblank\n");
 			goto out_bridge;
 		}
 	}

 	drm_mode_config_reset(dev);

 	drm_fb_cma_fbdev_init(dev, priv->variant->fb_bpp, 0);

 	drm_kms_helper_poll_init(dev);

 	goto finish;

 out_bridge:
 	if (panel)
 		drm_panel_bridge_remove(bridge);
 out_config:
 	drm_mode_config_cleanup(dev);
 finish:
 	return ret;
 }

 static struct drm_gem_object *
 pl111_gem_import_sg_table(struct drm_device *dev,
 			  struct dma_buf_attachment *attach,
 			  struct sg_table *sgt)
 {
 	struct pl111_drm_dev_private *priv = dev->dev_private;

 	/*
 	 * When using device-specific reserved memory we can't import
 	 * DMA buffers: those are passed by reference in any global
 	 * memory and we can only handle a specific range of memory.
 	 */
 	if (priv->use_device_memory)
 		return ERR_PTR(-EINVAL);

 	return drm_gem_cma_prime_import_sg_table(dev, attach, sgt);
 }

 DEFINE_DRM_GEM_CMA_FOPS(drm_fops);

 static struct drm_driver pl111_drm_driver = {
 	.driver_features =
 		DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_ATOMIC,
 	.lastclose = drm_fb_helper_lastclose,
 	.ioctls = NULL,
 	.fops = &drm_fops,
 	.name = "pl111",
 	.desc = DRIVER_DESC,
 	.date = "20170317",
 	.major = 1,
 	.minor = 0,
 	.patchlevel = 0,
 	.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_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_import_sg_table = pl111_gem_import_sg_table,
 	.gem_prime_export = drm_gem_prime_export,
 	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,

 #if defined(CONFIG_DEBUG_FS)
 	.debugfs_init = pl111_debugfs_init,
 #endif
 };

 static int pl111_amba_probe(struct amba_device *amba_dev,
 			    const struct amba_id *id)
 {
 	struct device *dev = &amba_dev->dev;
 	struct pl111_drm_dev_private *priv;
 	const struct pl111_variant_data *variant = id->data;
 	struct drm_device *drm;
 	int ret;

 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	drm = drm_dev_alloc(&pl111_drm_driver, dev);
 	if (IS_ERR(drm))
 		return PTR_ERR(drm);
 	amba_set_drvdata(amba_dev, drm);
 	priv->drm = drm;
 	drm->dev_private = priv;
 	priv->variant = variant;

 	ret = of_reserved_mem_device_init(dev);
 	if (!ret) {
 		dev_info(dev, "using device-specific reserved memory\n");
 		priv->use_device_memory = true;
 	}

 	if (of_property_read_u32(dev->of_node, "max-memory-bandwidth",
 				 &priv->memory_bw)) {
 		dev_info(dev, "no max memory bandwidth specified, assume unlimited\n");
 		priv->memory_bw = 0;
 	}

 	/* The two variants swap this register */
 	if (variant->is_pl110) {
 		priv->ienb = CLCD_PL110_IENB;
 		priv->ctrl = CLCD_PL110_CNTL;
 	} else {
 		priv->ienb = CLCD_PL111_IENB;
 		priv->ctrl = CLCD_PL111_CNTL;
 	}

 	priv->regs = devm_ioremap_resource(dev, &amba_dev->res);
 	if (IS_ERR(priv->regs)) {
 		dev_err(dev, "%s failed mmio\n", __func__);
 		ret = PTR_ERR(priv->regs);
 		goto dev_unref;
 	}

 	/* This may override some variant settings */
 	ret = pl111_versatile_init(dev, priv);
 	if (ret)
 		goto dev_unref;

 	/* turn off interrupts before requesting the irq */
 	writel(0, priv->regs + priv->ienb);

 	ret = devm_request_irq(dev, amba_dev->irq[0], pl111_irq, 0,
 			       variant->name, priv);
 	if (ret != 0) {
 		dev_err(dev, "%s failed irq %d\n", __func__, ret);
 		return ret;
 	}

 	ret = pl111_modeset_init(drm);
 	if (ret != 0)
 		goto dev_unref;

 	ret = drm_dev_register(drm, 0);
 	if (ret < 0)
 		goto dev_unref;

 	return 0;

 dev_unref:
 	drm_dev_unref(drm);
 	of_reserved_mem_device_release(dev);

 	return ret;
 }

 static int pl111_amba_remove(struct amba_device *amba_dev)
 {
 	struct device *dev = &amba_dev->dev;
 	struct drm_device *drm = amba_get_drvdata(amba_dev);
 	struct pl111_drm_dev_private *priv = drm->dev_private;

 	drm_dev_unregister(drm);
 	drm_fb_cma_fbdev_fini(drm);
 	if (priv->panel)
 		drm_panel_bridge_remove(priv->bridge);
 	drm_mode_config_cleanup(drm);
 	drm_dev_unref(drm);
 	of_reserved_mem_device_release(dev);

 	return 0;
 }

 /*
  * This early variant lacks the 565 and 444 pixel formats.
  */
 static const u32 pl110_pixel_formats[] = {
 	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XBGR8888,
 	DRM_FORMAT_ARGB8888,
 	DRM_FORMAT_XRGB8888,
 	DRM_FORMAT_ABGR1555,
 	DRM_FORMAT_XBGR1555,
 	DRM_FORMAT_ARGB1555,
 	DRM_FORMAT_XRGB1555,
 };

 static const struct pl111_variant_data pl110_variant = {
 	.name = "PL110",
 	.is_pl110 = true,
 	.formats = pl110_pixel_formats,
 	.nformats = ARRAY_SIZE(pl110_pixel_formats),
 	.fb_bpp = 16,
 };

 /* RealView, Versatile Express etc use this modern variant */
 static const u32 pl111_pixel_formats[] = {
 	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XBGR8888,
 	DRM_FORMAT_ARGB8888,
 	DRM_FORMAT_XRGB8888,
 	DRM_FORMAT_BGR565,
 	DRM_FORMAT_RGB565,
 	DRM_FORMAT_ABGR1555,
 	DRM_FORMAT_XBGR1555,
 	DRM_FORMAT_ARGB1555,
 	DRM_FORMAT_XRGB1555,
 	DRM_FORMAT_ABGR4444,
 	DRM_FORMAT_XBGR4444,
 	DRM_FORMAT_ARGB4444,
 	DRM_FORMAT_XRGB4444,
 };

 static const struct pl111_variant_data pl111_variant = {
 	.name = "PL111",
 	.formats = pl111_pixel_formats,
 	.nformats = ARRAY_SIZE(pl111_pixel_formats),
 	.fb_bpp = 32,
 };

 static const struct amba_id pl111_id_table[] = {
 	{
 		.id = 0x00041110,
 		.mask = 0x000fffff,
 		.data = (void*)&pl110_variant,
 	},
 	{
 		.id = 0x00041111,
 		.mask = 0x000fffff,
 		.data = (void*)&pl111_variant,
 	},
 	{0, 0},
 };

 static struct amba_driver pl111_amba_driver __maybe_unused = {
 	.drv = {
 		.name = "drm-clcd-pl111",
 	},
 	.probe = pl111_amba_probe,
 	.remove = pl111_amba_remove,
 	.id_table = pl111_id_table,
 };

 #ifdef CONFIG_ARM_AMBA
 module_amba_driver(pl111_amba_driver);
 #endif

 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_AUTHOR("ARM Ltd.");
 MODULE_LICENSE("GPL");
	/*
	* (C) COPYRIGHT 2012-2013 ARM Limited. All rights reserved.
	*
	* Parts of this file were based on sources as follows:
	*
	* Copyright (c) 2006-2008 Intel Corporation
	* Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
	* Copyright (C) 2011 Texas Instruments
	*
	* This program is free software and is provided to you under the terms of the
	* GNU General Public License version 2 as published by the Free Software
	* Foundation, and any use by you of this program is subject to the terms of
	* such GNU licence.
	*
	*/

	/**
	* DOC: ARM PrimeCell PL111 CLCD Driver
	*
	* The PL111 is a simple LCD controller that can support TFT and STN
	* displays. This driver exposes a standard KMS interface for them.
	*
	* This driver uses the same Device Tree binding as the fbdev CLCD
	* driver. While the fbdev driver supports panels that may be
	* connected to the CLCD internally to the CLCD driver, in DRM the
	* panels get split out to drivers/gpu/drm/panels/. This means that,
	* in converting from using fbdev to using DRM, you also need to write
	* a panel driver (which may be as simple as an entry in
	* panel-simple.c).
	*
	* The driver currently doesn't expose the cursor. The DRM API for
	* cursors requires support for 64x64 ARGB8888 cursor images, while
	* the hardware can only support 64x64 monochrome with masking
	* cursors. While one could imagine trying to hack something together
	* to look at the ARGB8888 and program reasonable in monochrome, we
	* just don't expose the cursor at all instead, and leave cursor
	* support to the X11 software cursor layer.
	*
	* TODO:
	*
	* - Fix race between setting plane base address and getting IRQ for
	* vsync firing the pageflip completion.
	*
	* - Use the "max-memory-bandwidth" DT property to filter the
	* supported formats.
	*
	* - Read back hardware state at boot to skip reprogramming the
	* hardware when doing a no-op modeset.
	*
	* - Use the CLKSEL bit to support switching between the two external
	* clock parents.
	*/

	#include <linux/amba/bus.h>
	#include <linux/amba/clcd-regs.h>
	#include <linux/version.h>
	#include <linux/shmem_fs.h>
	#include <linux/dma-buf.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/of.h>
	#include <linux/of_graph.h>
	#include <linux/of_reserved_mem.h>

	#include <drm/drmP.h>
	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_crtc_helper.h>
	#include <drm/drm_gem_cma_helper.h>
	#include <drm/drm_gem_framebuffer_helper.h>
	#include <drm/drm_fb_helper.h>
	#include <drm/drm_fb_cma_helper.h>
	#include <drm/drm_of.h>
	#include <drm/drm_bridge.h>
	#include <drm/drm_panel.h>

	#include "pl111_drm.h"
	#include "pl111_versatile.h"

	#define DRIVER_DESC "DRM module for PL111"

	static const struct drm_mode_config_funcs mode_config_funcs = {
	.fb_create = drm_gem_fb_create,
	.atomic_check = drm_atomic_helper_check,
	.atomic_commit = drm_atomic_helper_commit,
	};

	static int pl111_modeset_init(struct drm_device *dev)
	{
	struct drm_mode_config *mode_config;
	struct pl111_drm_dev_private *priv = dev->dev_private;
	struct device_node *np = dev->dev->of_node;
	struct device_node *remote;
	struct drm_panel *panel = NULL;
	struct drm_bridge *bridge = NULL;
	bool defer = false;
	int ret = 0;
	int i;

	drm_mode_config_init(dev);
	mode_config = &dev->mode_config;
	mode_config->funcs = &mode_config_funcs;
	mode_config->min_width = 1;
	mode_config->max_width = 1024;
	mode_config->min_height = 1;
	mode_config->max_height = 768;

	i = 0;
	for_each_endpoint_of_node(np, remote) {
	struct drm_panel *tmp_panel;
	struct drm_bridge *tmp_bridge;

	dev_dbg(dev->dev, "checking endpoint %d\n", i);

	ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
	0, i,
	&tmp_panel,
	&tmp_bridge);
	if (ret) {
	if (ret == -EPROBE_DEFER) {
	/*
	* Something deferred, but that is often just
	* another way of saying -ENODEV, but let's
	* cast a vote for later deferral.
	*/
	defer = true;
	} else if (ret != -ENODEV) {
	/* Continue, maybe something else is working */
	dev_err(dev->dev,
	"endpoint %d returns %d\n", i, ret);
	}
	}

	if (tmp_panel) {
	dev_info(dev->dev,
	"found panel on endpoint %d\n", i);
	panel = tmp_panel;
	}
	if (tmp_bridge) {
	dev_info(dev->dev,
	"found bridge on endpoint %d\n", i);
	bridge = tmp_bridge;
	}

	i++;
	}

	/*
	* If we can't find neither panel nor bridge on any of the
	* endpoints, and any of them retured -EPROBE_DEFER, then
	* let's defer this driver too.
	*/
	if ((!panel && !bridge) && defer)
	return -EPROBE_DEFER;

	if (panel) {
	bridge = drm_panel_bridge_add(panel,
	DRM_MODE_CONNECTOR_Unknown);
	if (IS_ERR(bridge)) {
	ret = PTR_ERR(bridge);
	goto out_config;
	}
	} else if (bridge) {
	dev_info(dev->dev, "Using non-panel bridge\n");
	} else {
	dev_err(dev->dev, "No bridge, exiting\n");
	return -ENODEV;
	}

	priv->bridge = bridge;
	if (panel) {
	priv->panel = panel;
	priv->connector = panel->connector;
	}

	ret = pl111_display_init(dev);
	if (ret != 0) {
	dev_err(dev->dev, "Failed to init display\n");
	goto out_bridge;
	}

	ret = drm_simple_display_pipe_attach_bridge(&priv->pipe,
	bridge);
	if (ret)
	return ret;

	if (!priv->variant->broken_vblank) {
	ret = drm_vblank_init(dev, 1);
	if (ret != 0) {
	dev_err(dev->dev, "Failed to init vblank\n");
	goto out_bridge;
	}
	}

	drm_mode_config_reset(dev);

	drm_fb_cma_fbdev_init(dev, priv->variant->fb_bpp, 0);

	drm_kms_helper_poll_init(dev);

	goto finish;

	out_bridge:
	if (panel)
	drm_panel_bridge_remove(bridge);
	out_config:
	drm_mode_config_cleanup(dev);
	finish:
	return ret;
	}

	static struct drm_gem_object *
	pl111_gem_import_sg_table(struct drm_device *dev,
	struct dma_buf_attachment *attach,
	struct sg_table *sgt)
	{
	struct pl111_drm_dev_private *priv = dev->dev_private;

	/*
	* When using device-specific reserved memory we can't import
	* DMA buffers: those are passed by reference in any global
	* memory and we can only handle a specific range of memory.
	*/
	if (priv->use_device_memory)
	return ERR_PTR(-EINVAL);

	return drm_gem_cma_prime_import_sg_table(dev, attach, sgt);
	}

	DEFINE_DRM_GEM_CMA_FOPS(drm_fops);

	static struct drm_driver pl111_drm_driver = {
	.driver_features =
	DRIVER_MODESET \| DRIVER_GEM \| DRIVER_PRIME \| DRIVER_ATOMIC,
	.lastclose = drm_fb_helper_lastclose,
	.ioctls = NULL,
	.fops = &drm_fops,
	.name = "pl111",
	.desc = DRIVER_DESC,
	.date = "20170317",
	.major = 1,
	.minor = 0,
	.patchlevel = 0,
	.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_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_import_sg_table = pl111_gem_import_sg_table,
	.gem_prime_export = drm_gem_prime_export,
	.gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,

	#if defined(CONFIG_DEBUG_FS)
	.debugfs_init = pl111_debugfs_init,
	#endif
	};

	static int pl111_amba_probe(struct amba_device *amba_dev,
	const struct amba_id *id)
	{
	struct device *dev = &amba_dev->dev;
	struct pl111_drm_dev_private *priv;
	const struct pl111_variant_data *variant = id->data;
	struct drm_device *drm;
	int ret;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	drm = drm_dev_alloc(&pl111_drm_driver, dev);
	if (IS_ERR(drm))
	return PTR_ERR(drm);
	amba_set_drvdata(amba_dev, drm);
	priv->drm = drm;
	drm->dev_private = priv;
	priv->variant = variant;

	ret = of_reserved_mem_device_init(dev);
	if (!ret) {
	dev_info(dev, "using device-specific reserved memory\n");
	priv->use_device_memory = true;
	}

	if (of_property_read_u32(dev->of_node, "max-memory-bandwidth",
	&priv->memory_bw)) {
	dev_info(dev, "no max memory bandwidth specified, assume unlimited\n");
	priv->memory_bw = 0;
	}

	/* The two variants swap this register */
	if (variant->is_pl110) {
	priv->ienb = CLCD_PL110_IENB;
	priv->ctrl = CLCD_PL110_CNTL;
	} else {
	priv->ienb = CLCD_PL111_IENB;
	priv->ctrl = CLCD_PL111_CNTL;
	}

	priv->regs = devm_ioremap_resource(dev, &amba_dev->res);
	if (IS_ERR(priv->regs)) {
	dev_err(dev, "%s failed mmio\n", __func__);
	ret = PTR_ERR(priv->regs);
	goto dev_unref;
	}

	/* This may override some variant settings */
	ret = pl111_versatile_init(dev, priv);
	if (ret)
	goto dev_unref;

	/* turn off interrupts before requesting the irq */
	writel(0, priv->regs + priv->ienb);

	ret = devm_request_irq(dev, amba_dev->irq[0], pl111_irq, 0,
	variant->name, priv);
	if (ret != 0) {
	dev_err(dev, "%s failed irq %d\n", __func__, ret);
	return ret;
	}

	ret = pl111_modeset_init(drm);
	if (ret != 0)
	goto dev_unref;

	ret = drm_dev_register(drm, 0);
	if (ret < 0)
	goto dev_unref;

	return 0;

	dev_unref:
	drm_dev_unref(drm);
	of_reserved_mem_device_release(dev);

	return ret;
	}

	static int pl111_amba_remove(struct amba_device *amba_dev)
	{
	struct device *dev = &amba_dev->dev;
	struct drm_device *drm = amba_get_drvdata(amba_dev);
	struct pl111_drm_dev_private *priv = drm->dev_private;

	drm_dev_unregister(drm);
	drm_fb_cma_fbdev_fini(drm);
	if (priv->panel)
	drm_panel_bridge_remove(priv->bridge);
	drm_mode_config_cleanup(drm);
	drm_dev_unref(drm);
	of_reserved_mem_device_release(dev);

	return 0;
	}

	/*
	* This early variant lacks the 565 and 444 pixel formats.
	*/
	static const u32 pl110_pixel_formats[] = {
	DRM_FORMAT_ABGR8888,
	DRM_FORMAT_XBGR8888,
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_ABGR1555,
	DRM_FORMAT_XBGR1555,
	DRM_FORMAT_ARGB1555,
	DRM_FORMAT_XRGB1555,
	};

	static const struct pl111_variant_data pl110_variant = {
	.name = "PL110",
	.is_pl110 = true,
	.formats = pl110_pixel_formats,
	.nformats = ARRAY_SIZE(pl110_pixel_formats),
	.fb_bpp = 16,
	};

	/* RealView, Versatile Express etc use this modern variant */
	static const u32 pl111_pixel_formats[] = {
	DRM_FORMAT_ABGR8888,
	DRM_FORMAT_XBGR8888,
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_BGR565,
	DRM_FORMAT_RGB565,
	DRM_FORMAT_ABGR1555,
	DRM_FORMAT_XBGR1555,
	DRM_FORMAT_ARGB1555,
	DRM_FORMAT_XRGB1555,
	DRM_FORMAT_ABGR4444,
	DRM_FORMAT_XBGR4444,
	DRM_FORMAT_ARGB4444,
	DRM_FORMAT_XRGB4444,
	};

	static const struct pl111_variant_data pl111_variant = {
	.name = "PL111",
	.formats = pl111_pixel_formats,
	.nformats = ARRAY_SIZE(pl111_pixel_formats),
	.fb_bpp = 32,
	};

	static const struct amba_id pl111_id_table[] = {
	{
	.id = 0x00041110,
	.mask = 0x000fffff,
	.data = (void*)&pl110_variant,
	},
	{
	.id = 0x00041111,
	.mask = 0x000fffff,
	.data = (void*)&pl111_variant,
	},
	{0, 0},
	};

	static struct amba_driver pl111_amba_driver __maybe_unused = {
	.drv = {
	.name = "drm-clcd-pl111",
	},
	.probe = pl111_amba_probe,
	.remove = pl111_amba_remove,
	.id_table = pl111_id_table,
	};

	#ifdef CONFIG_ARM_AMBA
	module_amba_driver(pl111_amba_driver);
	#endif

	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_AUTHOR("ARM Ltd.");
	MODULE_LICENSE("GPL");