drivers/gpu/drm/v3d/v3d_drv.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /* Copyright (C) 2014-2018 Broadcom */

 /**
  * DOC: Broadcom V3D Graphics Driver
  *
  * This driver supports the Broadcom V3D 3.3 and 4.1 OpenGL ES GPUs.
  * For V3D 2.x support, see the VC4 driver.
  *
  * Currently only single-core rendering using the binner and renderer
  * is supported.  The TFU (texture formatting unit) and V3D 4.x's CSD
  * (compute shader dispatch) are not yet supported.
  */

 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_fb_helper.h>

 #include "uapi/drm/v3d_drm.h"
 #include "v3d_drv.h"
 #include "v3d_regs.h"

 #define DRIVER_NAME "v3d"
 #define DRIVER_DESC "Broadcom V3D graphics"
 #define DRIVER_DATE "20180419"
 #define DRIVER_MAJOR 1
 #define DRIVER_MINOR 0
 #define DRIVER_PATCHLEVEL 0

 #ifdef CONFIG_PM
 static int v3d_runtime_suspend(struct device *dev)
 {
 	struct drm_device *drm = dev_get_drvdata(dev);
 	struct v3d_dev *v3d = to_v3d_dev(drm);

 	v3d_irq_disable(v3d);

 	clk_disable_unprepare(v3d->clk);

 	return 0;
 }

 static int v3d_runtime_resume(struct device *dev)
 {
 	struct drm_device *drm = dev_get_drvdata(dev);
 	struct v3d_dev *v3d = to_v3d_dev(drm);
 	int ret;

 	ret = clk_prepare_enable(v3d->clk);
 	if (ret != 0)
 		return ret;

 	/* XXX: VPM base */

 	v3d_mmu_set_page_table(v3d);
 	v3d_irq_enable(v3d);

 	return 0;
 }
 #endif

 static const struct dev_pm_ops v3d_v3d_pm_ops = {
 	SET_RUNTIME_PM_OPS(v3d_runtime_suspend, v3d_runtime_resume, NULL)
 };

 static int v3d_get_param_ioctl(struct drm_device *dev, void *data,
 			       struct drm_file *file_priv)
 {
 	struct v3d_dev *v3d = to_v3d_dev(dev);
 	struct drm_v3d_get_param *args = data;
 	int ret;
 	static const u32 reg_map[] = {
 		[DRM_V3D_PARAM_V3D_UIFCFG] = V3D_HUB_UIFCFG,
 		[DRM_V3D_PARAM_V3D_HUB_IDENT1] = V3D_HUB_IDENT1,
 		[DRM_V3D_PARAM_V3D_HUB_IDENT2] = V3D_HUB_IDENT2,
 		[DRM_V3D_PARAM_V3D_HUB_IDENT3] = V3D_HUB_IDENT3,
 		[DRM_V3D_PARAM_V3D_CORE0_IDENT0] = V3D_CTL_IDENT0,
 		[DRM_V3D_PARAM_V3D_CORE0_IDENT1] = V3D_CTL_IDENT1,
 		[DRM_V3D_PARAM_V3D_CORE0_IDENT2] = V3D_CTL_IDENT2,
 	};

 	if (args->pad != 0)
 		return -EINVAL;

 	/* Note that DRM_V3D_PARAM_V3D_CORE0_IDENT0 is 0, so we need
 	 * to explicitly allow it in the "the register in our
 	 * parameter map" check.
 	 */
 	if (args->param < ARRAY_SIZE(reg_map) &&
 	    (reg_map[args->param] ||
 	     args->param == DRM_V3D_PARAM_V3D_CORE0_IDENT0)) {
 		u32 offset = reg_map[args->param];

 		if (args->value != 0)
 			return -EINVAL;

 		ret = pm_runtime_get_sync(v3d->dev);
 		if (args->param >= DRM_V3D_PARAM_V3D_CORE0_IDENT0 &&
 		    args->param <= DRM_V3D_PARAM_V3D_CORE0_IDENT2) {
 			args->value = V3D_CORE_READ(0, offset);
 		} else {
 			args->value = V3D_READ(offset);
 		}
 		pm_runtime_mark_last_busy(v3d->dev);
 		pm_runtime_put_autosuspend(v3d->dev);
 		return 0;
 	}

 	/* Any params that aren't just register reads would go here. */

 	DRM_DEBUG("Unknown parameter %d\n", args->param);
 	return -EINVAL;
 }

 static int
 v3d_open(struct drm_device *dev, struct drm_file *file)
 {
 	struct v3d_dev *v3d = to_v3d_dev(dev);
 	struct v3d_file_priv *v3d_priv;
 	struct drm_sched_rq *rq;
 	int i;

 	v3d_priv = kzalloc(sizeof(*v3d_priv), GFP_KERNEL);
 	if (!v3d_priv)
 		return -ENOMEM;

 	v3d_priv->v3d = v3d;

 	for (i = 0; i < V3D_MAX_QUEUES; i++) {
 		rq = &v3d->queue[i].sched.sched_rq[DRM_SCHED_PRIORITY_NORMAL];
 		drm_sched_entity_init(&v3d_priv->sched_entity[i], &rq, 1, NULL);
 	}

 	file->driver_priv = v3d_priv;

 	return 0;
 }

 static void
 v3d_postclose(struct drm_device *dev, struct drm_file *file)
 {
 	struct v3d_file_priv *v3d_priv = file->driver_priv;
 	enum v3d_queue q;

 	for (q = 0; q < V3D_MAX_QUEUES; q++) {
 		drm_sched_entity_destroy(&v3d_priv->sched_entity[q]);
 	}

 	kfree(v3d_priv);
 }

 static const struct file_operations v3d_drm_fops = {
 	.owner = THIS_MODULE,
 	.open = drm_open,
 	.release = drm_release,
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = v3d_mmap,
 	.poll = drm_poll,
 	.read = drm_read,
 	.compat_ioctl = drm_compat_ioctl,
 	.llseek = noop_llseek,
 };

 /* DRM_AUTH is required on SUBMIT_CL for now, while we don't have GMP
  * protection between clients.  Note that render nodes would be be
  * able to submit CLs that could access BOs from clients authenticated
  * with the master node.
  */
 static const struct drm_ioctl_desc v3d_drm_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(V3D_SUBMIT_CL, v3d_submit_cl_ioctl, DRM_RENDER_ALLOW | DRM_AUTH),
 	DRM_IOCTL_DEF_DRV(V3D_WAIT_BO, v3d_wait_bo_ioctl, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(V3D_CREATE_BO, v3d_create_bo_ioctl, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(V3D_MMAP_BO, v3d_mmap_bo_ioctl, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(V3D_GET_PARAM, v3d_get_param_ioctl, DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(V3D_GET_BO_OFFSET, v3d_get_bo_offset_ioctl, DRM_RENDER_ALLOW),
 };

 static const struct vm_operations_struct v3d_vm_ops = {
 	.fault = v3d_gem_fault,
 	.open = drm_gem_vm_open,
 	.close = drm_gem_vm_close,
 };

 static struct drm_driver v3d_drm_driver = {
 	.driver_features = (DRIVER_GEM |
 			    DRIVER_RENDER |
 			    DRIVER_PRIME |
 			    DRIVER_SYNCOBJ),

 	.open = v3d_open,
 	.postclose = v3d_postclose,

 #if defined(CONFIG_DEBUG_FS)
 	.debugfs_init = v3d_debugfs_init,
 #endif

 	.gem_free_object_unlocked = v3d_free_object,
 	.gem_vm_ops = &v3d_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_export = drm_gem_prime_export,
 	.gem_prime_res_obj = v3d_prime_res_obj,
 	.gem_prime_get_sg_table	= v3d_prime_get_sg_table,
 	.gem_prime_import_sg_table = v3d_prime_import_sg_table,
 	.gem_prime_mmap = v3d_prime_mmap,

 	.ioctls = v3d_drm_ioctls,
 	.num_ioctls = ARRAY_SIZE(v3d_drm_ioctls),
 	.fops = &v3d_drm_fops,

 	.name = DRIVER_NAME,
 	.desc = DRIVER_DESC,
 	.date = DRIVER_DATE,
 	.major = DRIVER_MAJOR,
 	.minor = DRIVER_MINOR,
 	.patchlevel = DRIVER_PATCHLEVEL,
 };

 static const struct of_device_id v3d_of_match[] = {
 	{ .compatible = "brcm,7268-v3d" },
 	{ .compatible = "brcm,7278-v3d" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, v3d_of_match);

 static int
 map_regs(struct v3d_dev *v3d, void __iomem **regs, const char *name)
 {
 	struct resource *res =
 		platform_get_resource_byname(v3d->pdev, IORESOURCE_MEM, name);

 	*regs = devm_ioremap_resource(v3d->dev, res);
 	return PTR_ERR_OR_ZERO(*regs);
 }

 static int v3d_platform_drm_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct drm_device *drm;
 	struct v3d_dev *v3d;
 	int ret;
 	u32 ident1;

 	dev->coherent_dma_mask = DMA_BIT_MASK(36);

 	v3d = kzalloc(sizeof(*v3d), GFP_KERNEL);
 	if (!v3d)
 		return -ENOMEM;
 	v3d->dev = dev;
 	v3d->pdev = pdev;
 	drm = &v3d->drm;

 	ret = map_regs(v3d, &v3d->bridge_regs, "bridge");
 	if (ret)
 		goto dev_free;

 	ret = map_regs(v3d, &v3d->hub_regs, "hub");
 	if (ret)
 		goto dev_free;

 	ret = map_regs(v3d, &v3d->core_regs[0], "core0");
 	if (ret)
 		goto dev_free;

 	ident1 = V3D_READ(V3D_HUB_IDENT1);
 	v3d->ver = (V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_TVER) * 10 +
 		    V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_REV));
 	v3d->cores = V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_NCORES);
 	WARN_ON(v3d->cores > 1); /* multicore not yet implemented */

 	if (v3d->ver < 41) {
 		ret = map_regs(v3d, &v3d->gca_regs, "gca");
 		if (ret)
 			goto dev_free;
 	}

 	v3d->mmu_scratch = dma_alloc_wc(dev, 4096, &v3d->mmu_scratch_paddr,
 					GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
 	if (!v3d->mmu_scratch) {
 		dev_err(dev, "Failed to allocate MMU scratch page\n");
 		ret = -ENOMEM;
 		goto dev_free;
 	}

 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_set_autosuspend_delay(dev, 50);
 	pm_runtime_enable(dev);

 	ret = drm_dev_init(&v3d->drm, &v3d_drm_driver, dev);
 	if (ret)
 		goto dma_free;

 	platform_set_drvdata(pdev, drm);
 	drm->dev_private = v3d;

 	ret = v3d_gem_init(drm);
 	if (ret)
 		goto dev_destroy;

 	v3d_irq_init(v3d);

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

 	return 0;

 gem_destroy:
 	v3d_gem_destroy(drm);
 dev_destroy:
 	drm_dev_put(drm);
 dma_free:
 	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
 dev_free:
 	kfree(v3d);
 	return ret;
 }

 static int v3d_platform_drm_remove(struct platform_device *pdev)
 {
 	struct drm_device *drm = platform_get_drvdata(pdev);
 	struct v3d_dev *v3d = to_v3d_dev(drm);

 	drm_dev_unregister(drm);

 	v3d_gem_destroy(drm);

 	drm_dev_put(drm);

 	dma_free_wc(v3d->dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);

 	return 0;
 }

 static struct platform_driver v3d_platform_driver = {
 	.probe		= v3d_platform_drm_probe,
 	.remove		= v3d_platform_drm_remove,
 	.driver		= {
 		.name	= "v3d",
 		.of_match_table = v3d_of_match,
 	},
 };

 static int __init v3d_drm_register(void)
 {
 	return platform_driver_register(&v3d_platform_driver);
 }

 static void __exit v3d_drm_unregister(void)
 {
 	platform_driver_unregister(&v3d_platform_driver);
 }

 module_init(v3d_drm_register);
 module_exit(v3d_drm_unregister);

 MODULE_ALIAS("platform:v3d-drm");
 MODULE_DESCRIPTION("Broadcom V3D DRM Driver");
 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0+
	/* Copyright (C) 2014-2018 Broadcom */

	/**
	* DOC: Broadcom V3D Graphics Driver
	*
	* This driver supports the Broadcom V3D 3.3 and 4.1 OpenGL ES GPUs.
	* For V3D 2.x support, see the VC4 driver.
	*
	* Currently only single-core rendering using the binner and renderer
	* is supported. The TFU (texture formatting unit) and V3D 4.x's CSD
	* (compute shader dispatch) are not yet supported.
	*/

	#include <linux/clk.h>
	#include <linux/device.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of_platform.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <drm/drm_fb_cma_helper.h>
	#include <drm/drm_fb_helper.h>

	#include "uapi/drm/v3d_drm.h"
	#include "v3d_drv.h"
	#include "v3d_regs.h"

	#define DRIVER_NAME "v3d"
	#define DRIVER_DESC "Broadcom V3D graphics"
	#define DRIVER_DATE "20180419"
	#define DRIVER_MAJOR 1
	#define DRIVER_MINOR 0
	#define DRIVER_PATCHLEVEL 0

	#ifdef CONFIG_PM
	static int v3d_runtime_suspend(struct device *dev)
	{
	struct drm_device *drm = dev_get_drvdata(dev);
	struct v3d_dev *v3d = to_v3d_dev(drm);

	v3d_irq_disable(v3d);

	clk_disable_unprepare(v3d->clk);

	return 0;
	}

	static int v3d_runtime_resume(struct device *dev)
	{
	struct drm_device *drm = dev_get_drvdata(dev);
	struct v3d_dev *v3d = to_v3d_dev(drm);
	int ret;

	ret = clk_prepare_enable(v3d->clk);
	if (ret != 0)
	return ret;

	/* XXX: VPM base */

	v3d_mmu_set_page_table(v3d);
	v3d_irq_enable(v3d);

	return 0;
	}
	#endif

	static const struct dev_pm_ops v3d_v3d_pm_ops = {
	SET_RUNTIME_PM_OPS(v3d_runtime_suspend, v3d_runtime_resume, NULL)
	};

	static int v3d_get_param_ioctl(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct v3d_dev *v3d = to_v3d_dev(dev);
	struct drm_v3d_get_param *args = data;
	int ret;
	static const u32 reg_map[] = {
	[DRM_V3D_PARAM_V3D_UIFCFG] = V3D_HUB_UIFCFG,
	[DRM_V3D_PARAM_V3D_HUB_IDENT1] = V3D_HUB_IDENT1,
	[DRM_V3D_PARAM_V3D_HUB_IDENT2] = V3D_HUB_IDENT2,
	[DRM_V3D_PARAM_V3D_HUB_IDENT3] = V3D_HUB_IDENT3,
	[DRM_V3D_PARAM_V3D_CORE0_IDENT0] = V3D_CTL_IDENT0,
	[DRM_V3D_PARAM_V3D_CORE0_IDENT1] = V3D_CTL_IDENT1,
	[DRM_V3D_PARAM_V3D_CORE0_IDENT2] = V3D_CTL_IDENT2,
	};

	if (args->pad != 0)
	return -EINVAL;

	/* Note that DRM_V3D_PARAM_V3D_CORE0_IDENT0 is 0, so we need
	* to explicitly allow it in the "the register in our
	* parameter map" check.
	*/
	if (args->param < ARRAY_SIZE(reg_map) &&
	(reg_map[args->param] \|\|
	args->param == DRM_V3D_PARAM_V3D_CORE0_IDENT0)) {
	u32 offset = reg_map[args->param];

	if (args->value != 0)
	return -EINVAL;

	ret = pm_runtime_get_sync(v3d->dev);
	if (args->param >= DRM_V3D_PARAM_V3D_CORE0_IDENT0 &&
	args->param <= DRM_V3D_PARAM_V3D_CORE0_IDENT2) {
	args->value = V3D_CORE_READ(0, offset);
	} else {
	args->value = V3D_READ(offset);
	}
	pm_runtime_mark_last_busy(v3d->dev);
	pm_runtime_put_autosuspend(v3d->dev);
	return 0;
	}

	/* Any params that aren't just register reads would go here. */

	DRM_DEBUG("Unknown parameter %d\n", args->param);
	return -EINVAL;
	}

	static int
	v3d_open(struct drm_device dev, struct drm_file file)
	{
	struct v3d_dev *v3d = to_v3d_dev(dev);
	struct v3d_file_priv *v3d_priv;
	struct drm_sched_rq *rq;
	int i;

	v3d_priv = kzalloc(sizeof(*v3d_priv), GFP_KERNEL);
	if (!v3d_priv)
	return -ENOMEM;

	v3d_priv->v3d = v3d;

	for (i = 0; i < V3D_MAX_QUEUES; i++) {
	rq = &v3d->queue[i].sched.sched_rq[DRM_SCHED_PRIORITY_NORMAL];
	drm_sched_entity_init(&v3d_priv->sched_entity[i], &rq, 1, NULL);
	}

	file->driver_priv = v3d_priv;

	return 0;
	}

	static void
	v3d_postclose(struct drm_device dev, struct drm_file file)
	{
	struct v3d_file_priv *v3d_priv = file->driver_priv;
	enum v3d_queue q;

	for (q = 0; q < V3D_MAX_QUEUES; q++) {
	drm_sched_entity_destroy(&v3d_priv->sched_entity[q]);
	}

	kfree(v3d_priv);
	}

	static const struct file_operations v3d_drm_fops = {
	.owner = THIS_MODULE,
	.open = drm_open,
	.release = drm_release,
	.unlocked_ioctl = drm_ioctl,
	.mmap = v3d_mmap,
	.poll = drm_poll,
	.read = drm_read,
	.compat_ioctl = drm_compat_ioctl,
	.llseek = noop_llseek,
	};

	/* DRM_AUTH is required on SUBMIT_CL for now, while we don't have GMP
	* protection between clients. Note that render nodes would be be
	* able to submit CLs that could access BOs from clients authenticated
	* with the master node.
	*/
	static const struct drm_ioctl_desc v3d_drm_ioctls[] = {
	DRM_IOCTL_DEF_DRV(V3D_SUBMIT_CL, v3d_submit_cl_ioctl, DRM_RENDER_ALLOW \| DRM_AUTH),
	DRM_IOCTL_DEF_DRV(V3D_WAIT_BO, v3d_wait_bo_ioctl, DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF_DRV(V3D_CREATE_BO, v3d_create_bo_ioctl, DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF_DRV(V3D_MMAP_BO, v3d_mmap_bo_ioctl, DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF_DRV(V3D_GET_PARAM, v3d_get_param_ioctl, DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF_DRV(V3D_GET_BO_OFFSET, v3d_get_bo_offset_ioctl, DRM_RENDER_ALLOW),
	};

	static const struct vm_operations_struct v3d_vm_ops = {
	.fault = v3d_gem_fault,
	.open = drm_gem_vm_open,
	.close = drm_gem_vm_close,
	};

	static struct drm_driver v3d_drm_driver = {
	.driver_features = (DRIVER_GEM \|
	DRIVER_RENDER \|
	DRIVER_PRIME \|
	DRIVER_SYNCOBJ),

	.open = v3d_open,
	.postclose = v3d_postclose,

	#if defined(CONFIG_DEBUG_FS)
	.debugfs_init = v3d_debugfs_init,
	#endif

	.gem_free_object_unlocked = v3d_free_object,
	.gem_vm_ops = &v3d_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_export = drm_gem_prime_export,
	.gem_prime_res_obj = v3d_prime_res_obj,
	.gem_prime_get_sg_table = v3d_prime_get_sg_table,
	.gem_prime_import_sg_table = v3d_prime_import_sg_table,
	.gem_prime_mmap = v3d_prime_mmap,

	.ioctls = v3d_drm_ioctls,
	.num_ioctls = ARRAY_SIZE(v3d_drm_ioctls),
	.fops = &v3d_drm_fops,

	.name = DRIVER_NAME,
	.desc = DRIVER_DESC,
	.date = DRIVER_DATE,
	.major = DRIVER_MAJOR,
	.minor = DRIVER_MINOR,
	.patchlevel = DRIVER_PATCHLEVEL,
	};

	static const struct of_device_id v3d_of_match[] = {
	{ .compatible = "brcm,7268-v3d" },
	{ .compatible = "brcm,7278-v3d" },
	{},
	};
	MODULE_DEVICE_TABLE(of, v3d_of_match);

	static int
	map_regs(struct v3d_dev v3d, void __iomem regs, const char name)
	{
	struct resource *res =
	platform_get_resource_byname(v3d->pdev, IORESOURCE_MEM, name);

	*regs = devm_ioremap_resource(v3d->dev, res);
	return PTR_ERR_OR_ZERO(*regs);
	}

	static int v3d_platform_drm_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct drm_device *drm;
	struct v3d_dev *v3d;
	int ret;
	u32 ident1;

	dev->coherent_dma_mask = DMA_BIT_MASK(36);

	v3d = kzalloc(sizeof(*v3d), GFP_KERNEL);
	if (!v3d)
	return -ENOMEM;
	v3d->dev = dev;
	v3d->pdev = pdev;
	drm = &v3d->drm;

	ret = map_regs(v3d, &v3d->bridge_regs, "bridge");
	if (ret)
	goto dev_free;

	ret = map_regs(v3d, &v3d->hub_regs, "hub");
	if (ret)
	goto dev_free;

	ret = map_regs(v3d, &v3d->core_regs[0], "core0");
	if (ret)
	goto dev_free;

	ident1 = V3D_READ(V3D_HUB_IDENT1);
	v3d->ver = (V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_TVER) * 10 +
	V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_REV));
	v3d->cores = V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_NCORES);
	WARN_ON(v3d->cores > 1); /* multicore not yet implemented */

	if (v3d->ver < 41) {
	ret = map_regs(v3d, &v3d->gca_regs, "gca");
	if (ret)
	goto dev_free;
	}

	v3d->mmu_scratch = dma_alloc_wc(dev, 4096, &v3d->mmu_scratch_paddr,
	GFP_KERNEL \| __GFP_NOWARN \| __GFP_ZERO);
	if (!v3d->mmu_scratch) {
	dev_err(dev, "Failed to allocate MMU scratch page\n");
	ret = -ENOMEM;
	goto dev_free;
	}

	pm_runtime_use_autosuspend(dev);
	pm_runtime_set_autosuspend_delay(dev, 50);
	pm_runtime_enable(dev);

	ret = drm_dev_init(&v3d->drm, &v3d_drm_driver, dev);
	if (ret)
	goto dma_free;

	platform_set_drvdata(pdev, drm);
	drm->dev_private = v3d;

	ret = v3d_gem_init(drm);
	if (ret)
	goto dev_destroy;

	v3d_irq_init(v3d);

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

	return 0;

	gem_destroy:
	v3d_gem_destroy(drm);
	dev_destroy:
	drm_dev_put(drm);
	dma_free:
	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
	dev_free:
	kfree(v3d);
	return ret;
	}

	static int v3d_platform_drm_remove(struct platform_device *pdev)
	{
	struct drm_device *drm = platform_get_drvdata(pdev);
	struct v3d_dev *v3d = to_v3d_dev(drm);

	drm_dev_unregister(drm);

	v3d_gem_destroy(drm);

	drm_dev_put(drm);

	dma_free_wc(v3d->dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);

	return 0;
	}

	static struct platform_driver v3d_platform_driver = {
	.probe = v3d_platform_drm_probe,
	.remove = v3d_platform_drm_remove,
	.driver = {
	.name = "v3d",
	.of_match_table = v3d_of_match,
	},
	};

	static int __init v3d_drm_register(void)
	{
	return platform_driver_register(&v3d_platform_driver);
	}

	static void __exit v3d_drm_unregister(void)
	{
	platform_driver_unregister(&v3d_platform_driver);
	}

	module_init(v3d_drm_register);
	module_exit(v3d_drm_unregister);

	MODULE_ALIAS("platform:v3d-drm");
	MODULE_DESCRIPTION("Broadcom V3D DRM Driver");
	MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
	MODULE_LICENSE("GPL v2");