Re: [v1,v1,5/7] drm/vs: Register DRM device

[suijingfeng]

Hi,


On 2023/8/1 18:10, Keith Zhao wrote:
> Implement drm device registration interface
>
> Signed-off-by: Keith Zhao <keith.zhao@xxxxxxxxxxxxxxxx>
> ---
>   drivers/gpu/drm/Kconfig                  |   2 +
>   drivers/gpu/drm/Makefile                 |   1 +
>   drivers/gpu/drm/verisilicon/Kconfig      |  25 ++
>   drivers/gpu/drm/verisilicon/Makefile     |  13 +
>   drivers/gpu/drm/verisilicon/vs_drv.c     | 273 +++++++++++++++++++++
>   drivers/gpu/drm/verisilicon/vs_drv.h     |  54 ++++
>   drivers/gpu/drm/verisilicon/vs_gem.c     | 298 +++++++++++++++++++++++
>   drivers/gpu/drm/verisilicon/vs_gem.h     |  50 ++++
>   drivers/gpu/drm/verisilicon/vs_modeset.c |  92 +++++++
>   drivers/gpu/drm/verisilicon/vs_modeset.h |  13 +
>   include/uapi/drm/vs_drm.h                |  50 ++++
>   11 files changed, 871 insertions(+)
>   create mode 100644 drivers/gpu/drm/verisilicon/Kconfig
>   create mode 100644 drivers/gpu/drm/verisilicon/Makefile
>   create mode 100644 drivers/gpu/drm/verisilicon/vs_drv.c
>   create mode 100644 drivers/gpu/drm/verisilicon/vs_drv.h
>   create mode 100644 drivers/gpu/drm/verisilicon/vs_gem.c
>   create mode 100644 drivers/gpu/drm/verisilicon/vs_gem.h
>   create mode 100644 drivers/gpu/drm/verisilicon/vs_modeset.c
>   create mode 100644 drivers/gpu/drm/verisilicon/vs_modeset.h
>   create mode 100644 include/uapi/drm/vs_drm.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index afb3b2f5f..9ede80ef9 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -363,6 +363,8 @@ source "drivers/gpu/drm/solomon/Kconfig"
>   
>   source "drivers/gpu/drm/sprd/Kconfig"
>   
> +source "drivers/gpu/drm/verisilicon/Kconfig"
> +
>   config DRM_HYPERV
>   	tristate "DRM Support for Hyper-V synthetic video device"
>   	depends on DRM && PCI && MMU && HYPERV
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 7a09a89b4..6db3bc397 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -194,3 +194,4 @@ obj-y			+= gud/
>   obj-$(CONFIG_DRM_HYPERV) += hyperv/
>   obj-y			+= solomon/
>   obj-$(CONFIG_DRM_SPRD) += sprd/
> +obj-$(CONFIG_DRM_VERISILICON) += verisilicon/
> diff --git a/drivers/gpu/drm/verisilicon/Kconfig b/drivers/gpu/drm/verisilicon/Kconfig
> new file mode 100644
> index 000000000..fcc39dded
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/Kconfig
> @@ -0,0 +1,25 @@
> +# SPDX-License-Identifier: GPL-2.0
> +config DRM_VERISILICON
> +	tristate "DRM Support for VeriSilicon"
> +	depends on DRM
> +	select DRM_KMS_HELPER
> +	select DRM_GEM_DMA_HELPER
> +	select CMA
> +	select DMA_CMA
> +	help
> +	  Choose this option if you have a VeriSilicon soc chipset.
> +	  This driver provides VeriSilicon kernel mode
> +	  setting and buffer management. It does not
> +	  provide 2D or 3D acceleration.
> +
> +if DRM_VERISILICON
> +
> +config STARFIVE_HDMI
> +	bool "Starfive specific extensions HDMI"
> +	help
> +	   This selects support for StarFive SoC specific extensions
> +	   for the Innosilicon HDMI driver. If you want to enable
> +	   HDMI on JH7110 based SoC, you should select this option.
> +
> +	   To compile this driver as a module, choose M here.
> +endif

Why not use


> diff --git a/drivers/gpu/drm/verisilicon/Makefile b/drivers/gpu/drm/verisilicon/Makefile
> new file mode 100644
> index 000000000..26cc7e21b
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/Makefile
> @@ -0,0 +1,13 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +vs_drm-objs := vs_dc_hw.o \
> +		vs_dc.o \
> +		vs_crtc.o \
> +		vs_drv.o \
> +		vs_modeset.o \
> +		vs_gem.o \
> +		vs_plane.o
> +
> +vs_drm-$(CONFIG_STARFIVE_HDMI) += starfive_hdmi.o
> +obj-$(CONFIG_DRM_VERISILICON) += vs_drm.o
> +
> diff --git a/drivers/gpu/drm/verisilicon/vs_drv.c b/drivers/gpu/drm/verisilicon/vs_drv.c
> new file mode 100644
> index 000000000..69591e640
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_drv.c
> @@ -0,0 +1,273 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/component.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/iommu.h>
> +#include <linux/of_graph.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/version.h>
> +
> +#include <drm/drm_aperture.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_debugfs.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_fbdev_generic.h>
> +#include <drm/drm_file.h>
> +#include <drm/drm_fourcc.h>
> +#include <drm/drm_ioctl.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_prime.h>
> +#include <drm/drm_probe_helper.h>
> +#include <drm/drm_vblank.h>
> +
> +#include "vs_drv.h"
> +#include "vs_modeset.h"
> +#include "vs_gem.h"
> +
> +#define DRV_NAME	"starfive"
> +#define DRV_DESC	"Starfive DRM driver"
> +#define DRV_DATE	"202305161"

The date is not correct here, generally it should have 8 numbers,

while you have 9 digits, why you are so special ?


> +#define DRV_MAJOR	1
> +#define DRV_MINOR	0
> +
> +static struct platform_driver vs_drm_platform_driver;
> +
> +static const struct file_operations fops = {
> +	.owner			= THIS_MODULE,
> +	.open			= drm_open,
> +	.release		= drm_release,
> +	.unlocked_ioctl	= drm_ioctl,
> +	.compat_ioctl	= drm_compat_ioctl,
> +	.poll			= drm_poll,
> +	.read			= drm_read,
> +	.mmap			= drm_gem_mmap,
> +};
> +
> +static struct drm_driver vs_drm_driver = {
> +	.driver_features	= DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
> +	.lastclose		= drm_fb_helper_lastclose,
> +	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> +	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,


You are not using drm-tip branch, in normal case, new patch for drm 
should be compile against the drm-tip branch.

the drm_gem_prime_handle_to_fd() and drm_gem_prime_fd_to_handle() function is not be exported anymore.

see 71a7974ac7019 ('drm/prime: Unexport helpers for fd/handle conversion')

So, you patch will be pass the compile test, I guess.


> +	.gem_prime_import_sg_table = vs_gem_prime_import_sg_table,


By implement gem_prime_import_sg_table, while in curiosity,

which drivers you are import the shared buffer from ?

Is this vs_gem_prime_import_sg_table() function really has been used and 
tested ?


As far as I could understand, most embedded SoC using KMS-RO framework.

By using the KMS-RO framework, typically the GPU driver will import 
buffer from the Display controller.

So, why you need implement this function interface?


> +	.gem_prime_mmap		= drm_gem_prime_mmap,


This hook is(or going to be) obsolete,  see 0adec22702d4 ('drm: Remove 
struct drm_driver.gem_prime_mmap')


> +	.dumb_create		= vs_gem_dumb_create,
> +	.fops			= &fops,
> +	.name			= DRV_NAME,
> +	.desc			= DRV_DESC,
> +	.date			= DRV_DATE,
> +	.major			= DRV_MAJOR,
> +	.minor			= DRV_MINOR,
> +};
> +
> +void vs_drm_update_pitch_alignment(struct drm_device *drm_dev,
> +				   unsigned int alignment)
> +{
> +	struct vs_drm_private *priv = to_vs_dev(drm_dev);
> +
> +	if (alignment > priv->pitch_alignment)
> +		priv->pitch_alignment = alignment;
> +}
> +
> +static int vs_drm_bind(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct vs_drm_private *priv;
> +	int ret;
> +	static u64 dma_mask = DMA_BIT_MASK(40);
> +	struct drm_device *drm_dev;
> +
> +	/* Remove existing drivers that may own the framebuffer memory. */
> +	ret = drm_aperture_remove_framebuffers(&vs_drm_driver);
> +	if (ret) {
> +		dev_err(dev,
> +			    "Failed to remove existing framebuffers - %d.\n",
> +			    ret);
> +		return ret;
> +	}
> +
> +	priv = devm_drm_dev_alloc(dev, &vs_drm_driver, struct vs_drm_private, base);
> +		if (IS_ERR(priv))
> +			return PTR_ERR(priv);
> +
> +	priv->pitch_alignment = 64;
> +	priv->dma_dev = priv->base.dev;
> +	priv->dma_dev->coherent_dma_mask = dma_mask;
> +	drm_dev = &priv->base;
> +	platform_set_drvdata(pdev, drm_dev);
> +
> +	vs_mode_config_init(drm_dev);
> +
> +	/* Now try and bind all our sub-components */
> +	ret = component_bind_all(dev, drm_dev);
> +	if (ret)
> +		goto err_mode;
> +
> +	ret = drm_vblank_init(drm_dev, drm_dev->mode_config.num_crtc);
> +	if (ret)
> +		goto err_bind;
> +
> +	drm_mode_config_reset(drm_dev);
> +
> +	drm_kms_helper_poll_init(drm_dev);
> +
> +	ret = drm_dev_register(drm_dev, 0);
> +	if (ret)
> +		goto err_helper;
> +
> +	drm_fbdev_generic_setup(drm_dev, 32);
> +
> +	return 0;
> +
> +err_helper:
> +	drm_kms_helper_poll_fini(drm_dev);
> +err_bind:
> +	component_unbind_all(drm_dev->dev, drm_dev);
> +err_mode:
> +	drm_mode_config_cleanup(drm_dev);
> +
> +	return ret;
> +}
> +
> +static void vs_drm_unbind(struct device *dev)
> +{
> +	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +
> +	drm_dev_unregister(drm_dev);
> +
> +	drm_kms_helper_poll_fini(drm_dev);
> +
> +	component_unbind_all(drm_dev->dev, drm_dev);
> +}
> +
> +static const struct component_master_ops vs_drm_ops = {
> +	.bind = vs_drm_bind,
> +	.unbind = vs_drm_unbind,
> +};
> +
> +static struct platform_driver *drm_sub_drivers[] = {
> +
> +
> +	/* connector + encoder*/
> +#ifdef CONFIG_STARFIVE_HDMI
> +	&starfive_hdmi_driver,
> +#endif
> +
> +};
> +
> +#define NUM_DRM_DRIVERS \
> +	(sizeof(drm_sub_drivers) / sizeof(struct platform_driver *))

I think, the macro is bad name,

you have only one drm drivers, all of the rest are sub platform drivers

which need to bind to the only one drm master.

> +static int compare_dev(struct device *dev, void *data)
> +{
> +	return dev == (struct device *)data;
> +}
> +

There already has a 'component_compare_dev()' defined in component.c 
(see include/linux/component.h)

why you need want implement one yourself.


> +static struct component_match *vs_drm_match_add(struct device *dev)
> +{
> +	struct component_match *match = NULL;
> +	int i;
> +
> +	for (i = 0; i < NUM_DRM_DRIVERS; ++i) {
> +		struct platform_driver *drv = drm_sub_drivers[i];
> +		struct device *p = NULL, *d;
> +
> +		while ((d = platform_find_device_by_driver(p, &drv->driver))) {
> +			put_device(p);
> +
> +			component_match_add(dev, &match, compare_dev, d);
> +			p = d;
> +		}
> +		put_device(p);
> +	}
> +
> +	return match ?: ERR_PTR(-ENODEV);
> +}
> +
> +static int vs_drm_platform_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct component_match *match;
> +
> +	match = vs_drm_match_add(dev);
> +	if (IS_ERR(match))
> +		return PTR_ERR(match);
> +
> +	return component_master_add_with_match(dev, &vs_drm_ops, match);
> +}
> +
> +static int vs_drm_platform_remove(struct platform_device *pdev)
> +{
> +	component_master_del(&pdev->dev, &vs_drm_ops);
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int vs_drm_suspend(struct device *dev)
> +{
> +	return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
> +}
> +
> +static int vs_drm_resume(struct device *dev)
> +{
> +	drm_mode_config_helper_resume(dev_get_drvdata(dev));
> +
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(vs_drm_pm_ops, vs_drm_suspend, vs_drm_resume);
> +
> +static const struct of_device_id vs_drm_dt_ids[] = {
> +	{ .compatible = "starfive,display-subsystem", },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, vs_drm_dt_ids);
> +
> +static struct platform_driver vs_drm_platform_driver = {
> +	.probe = vs_drm_platform_probe,
> +	.remove = vs_drm_platform_remove,
> +
> +	.driver = {
> +		.name = DRV_NAME,
> +		.of_match_table = vs_drm_dt_ids,
> +		.pm = &vs_drm_pm_ops,
> +	},
> +};
> +
> +static int __init vs_drm_init(void)
> +{
> +	int ret;
> +
> +	ret = platform_register_drivers(drm_sub_drivers, NUM_DRM_DRIVERS);
> +	if (ret)
> +		return ret;
> +
> +	ret = platform_driver_register(&vs_drm_platform_driver);
> +	if (ret)
> +		platform_unregister_drivers(drm_sub_drivers, NUM_DRM_DRIVERS);
> +
> +	return ret;
> +}
> +
> +static void __exit vs_drm_fini(void)
> +{
> +	platform_driver_unregister(&vs_drm_platform_driver);
> +	platform_unregister_drivers(drm_sub_drivers, NUM_DRM_DRIVERS);
> +}
> +
> +module_init(vs_drm_init);
> +module_exit(vs_drm_fini);
> +
> +MODULE_DESCRIPTION("VeriSilicon DRM Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/verisilicon/vs_drv.h b/drivers/gpu/drm/verisilicon/vs_drv.h
> new file mode 100644
> index 000000000..6ddc99dcf
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_drv.h
> @@ -0,0 +1,54 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#ifndef __VS_DRV_H__
> +#define __VS_DRV_H__
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/version.h>
> +#include <drm/drm_drv.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_managed.h>
> +
> +/*
> + *
> + * @dma_dev: device for DMA API.
> + *	- use the first attached device if support iommu
> +	else use drm device (only contiguous buffer support)
> + * @domain: iommu domain for DRM.
> + *	- all DC IOMMU share same domain to reduce mapping
> + * @pitch_alignment: buffer pitch alignment required by sub-devices.
> + *
> + */
> +struct vs_drm_private {
> +	struct drm_device base;
> +	struct device *dma_dev;
> +	struct iommu_domain *domain;
> +	unsigned int pitch_alignment;
> +};
> +
> +static inline struct vs_drm_private *
> +to_vs_dev(const struct drm_device *dev)
> +{
> +	return container_of(dev, struct vs_drm_private, base);
> +}
> +
> +void vs_drm_update_pitch_alignment(struct drm_device *drm_dev,
> +				   unsigned int alignment);
> +
> +
> +static inline bool is_iommu_enabled(struct drm_device *dev)
> +{
> +	struct vs_drm_private *priv = to_vs_dev(dev);
> +
> +	return priv->domain ? true : false;
> +}
> +
> +#ifdef CONFIG_STARFIVE_HDMI
> +extern struct platform_driver starfive_hdmi_driver;
> +#endif
> +
> +#endif /* __VS_DRV_H__ */
> diff --git a/drivers/gpu/drm/verisilicon/vs_gem.c b/drivers/gpu/drm/verisilicon/vs_gem.c
> new file mode 100644
> index 000000000..a7d5a5c7b
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_gem.c
> @@ -0,0 +1,298 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#include <linux/dma-buf.h>
> +#include <linux/of_reserved_mem.h>
> +#include <drm/drm_gem_dma_helper.h>
> +
> +#include "vs_drv.h"
> +#include "vs_gem.h"
> +
> +MODULE_IMPORT_NS(DMA_BUF);
> +
> +static const struct drm_gem_object_funcs vs_gem_default_funcs;
> +
> +static int vs_gem_alloc_buf(struct vs_gem_object *vs_obj)
> +{
> +	struct drm_device *dev = vs_obj->base.base.dev;
> +	unsigned int nr_pages;
> +	struct sg_table sgt;
> +	int ret = -ENOMEM;
> +
> +	if (vs_obj->base.dma_addr) {
> +		drm_dbg_kms(dev, "already allocated.\n");
> +		return 0;
> +	}
> +
> +	vs_obj->base.dma_addr = DMA_ATTR_WRITE_COMBINE | DMA_ATTR_FORCE_CONTIGUOUS
> +			   | DMA_ATTR_NO_KERNEL_MAPPING;
> +
> +	nr_pages = vs_obj->base.base.size >> PAGE_SHIFT;
> +
> +	vs_obj->pages = kvmalloc_array(nr_pages, sizeof(struct page *),
> +				       GFP_KERNEL | __GFP_ZERO);
> +	if (!vs_obj->pages)
> +		return -ENOMEM;
> +
> +	vs_obj->cookie = dma_alloc_attrs(dev->dev, vs_obj->base.base.size,
> +					 &vs_obj->base.dma_addr, GFP_KERNEL,
> +					 vs_obj->dma_attrs);
> +
> +	if (!vs_obj->cookie) {
> +		dev_err(dev->dev, "failed to allocate buffer.\n");
> +		goto err_free;
> +	}
> +
> +	vs_obj->iova = vs_obj->base.dma_addr;
> +
> +	ret = dma_get_sgtable_attrs(dev->dev, &sgt,
> +				    vs_obj->cookie, vs_obj->base.dma_addr,
> +				    vs_obj->base.base.size, vs_obj->dma_attrs);
> +	if (ret < 0) {
> +		dev_err(dev->dev, "failed to get sgtable.\n");
> +		goto err_mem_free;
> +	}
> +
> +	if (drm_prime_sg_to_page_array(&sgt, vs_obj->pages, nr_pages)) {
> +		dev_err(dev->dev, "invalid sgtable.\n");
> +		ret = -EINVAL;
> +		goto err_sgt_free;
> +	}
> +
> +	sg_free_table(&sgt);
> +
> +	return 0;
> +
> +err_sgt_free:
> +	sg_free_table(&sgt);
> +err_mem_free:
> +		dma_free_attrs(dev->dev, vs_obj->base.base.size, vs_obj->cookie,
> +			       vs_obj->base.dma_addr, vs_obj->dma_attrs);
> +err_free:
> +	kvfree(vs_obj->pages);
> +
> +	return ret;
> +}
> +
> +static void vs_gem_free_buf(struct vs_gem_object *vs_obj)
> +{
> +	struct drm_device *dev = vs_obj->base.base.dev;
> +
> +	if (!vs_obj->base.dma_addr) {
> +		drm_dbg_kms(dev, "dma_addr is invalid.\n");
> +		return;
> +	}
> +
> +	dma_free_attrs(dev->dev, vs_obj->base.base.size, vs_obj->cookie,
> +		       (dma_addr_t)vs_obj->base.dma_addr,
> +		       vs_obj->dma_attrs);
> +
> +	kvfree(vs_obj->pages);
> +}
> +
> +static void vs_gem_free_object(struct drm_gem_object *obj)
> +{
> +	struct vs_gem_object *vs_obj = to_vs_gem_object(obj);
> +
> +	if (obj->import_attach)
> +		drm_prime_gem_destroy(obj, vs_obj->base.sgt);
> +	else
> +		vs_gem_free_buf(vs_obj);
> +
> +	drm_gem_object_release(obj);
> +
> +	kfree(vs_obj);
> +}
> +
> +static struct vs_gem_object *vs_gem_alloc_object(struct drm_device *dev,
> +						 size_t size)
> +{
> +	struct vs_gem_object *vs_obj;
> +	struct drm_gem_object *obj;
> +	int ret;
> +
> +	vs_obj = kzalloc(sizeof(*vs_obj), GFP_KERNEL);
> +	if (!vs_obj)
> +		return ERR_PTR(-ENOMEM);
> +
> +	vs_obj->base.base.size = size;
> +	obj = &vs_obj->base.base;
> +
> +	ret = drm_gem_object_init(dev, obj, size);
> +	if (ret)
> +		goto err_free;
> +
> +	vs_obj->base.base.funcs = &vs_gem_default_funcs;
> +
> +	ret = drm_gem_create_mmap_offset(obj);
> +	if (ret) {
> +		drm_gem_object_release(obj);
> +		goto err_free;
> +	}
> +
> +	return vs_obj;
> +
> +err_free:
> +	kfree(vs_obj);
> +	return ERR_PTR(ret);
> +}
> +
> +static struct vs_gem_object *vs_gem_create_object(struct drm_device *dev,
> +						  size_t size)
> +{
> +	struct vs_gem_object *vs_obj;
> +	int ret;
> +
> +	size = PAGE_ALIGN(size);
> +
> +	vs_obj = vs_gem_alloc_object(dev, size);
> +	if (IS_ERR(vs_obj))
> +		return vs_obj;
> +
> +	ret = vs_gem_alloc_buf(vs_obj);
> +	if (ret) {
> +		drm_gem_object_release(&vs_obj->base.base);
> +		kfree(vs_obj);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return vs_obj;
> +}
> +
> +static struct vs_gem_object *vs_gem_create_with_handle(struct drm_device *dev,
> +						       struct drm_file *file,
> +						       size_t size,
> +						       unsigned int *handle)
> +{
> +	struct vs_gem_object *vs_obj;
> +	struct drm_gem_object *obj;
> +	int ret;
> +
> +	vs_obj = vs_gem_create_object(dev, size);
> +	if (IS_ERR(vs_obj))
> +		return vs_obj;
> +
> +	obj = &vs_obj->base.base;
> +
> +	ret = drm_gem_handle_create(file, obj, handle);
> +
> +	drm_gem_object_put(obj);
> +
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return vs_obj;
> +}
> +
> +static struct sg_table *vs_gem_prime_get_sg_table(struct drm_gem_object *obj)
> +{
> +	struct vs_gem_object *vs_obj = to_vs_gem_object(obj);
> +
> +	return drm_prime_pages_to_sg(obj->dev, vs_obj->pages,
> +					 vs_obj->base.base.size >> PAGE_SHIFT);
> +}
> +
> +static int vs_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
> +{
> +	struct vs_gem_object *vs_obj = to_vs_gem_object(obj);
> +
> +	vs_obj->base.vaddr = vs_obj->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING ?
> +		       page_address(vs_obj->cookie) : vs_obj->cookie;
> +
> +	return drm_gem_dma_vmap(&vs_obj->base, map);
> +}
> +
> +static const struct vm_operations_struct vs_vm_ops = {
> +	.open  = drm_gem_vm_open,
> +	.close = drm_gem_vm_close,
> +};
> +
> +static const struct drm_gem_object_funcs vs_gem_default_funcs = {
> +	.free = vs_gem_free_object,
> +	.get_sg_table = vs_gem_prime_get_sg_table,
> +	.vmap = vs_gem_prime_vmap,
> +	.mmap = drm_gem_dma_object_mmap,
> +	.vm_ops = &vs_vm_ops,
> +};
> +
> +int vs_gem_dumb_create(struct drm_file *file,
> +		       struct drm_device *dev,
> +		       struct drm_mode_create_dumb *args)
> +{
> +	struct vs_drm_private *priv = to_vs_dev(dev);
> +	struct vs_gem_object *vs_obj;
> +	unsigned int pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
> +
> +	if (args->bpp % 10)
> +		args->pitch = ALIGN(pitch, priv->pitch_alignment);
> +	else
> +		/* for costum 10bit format with no bit gaps */
> +		args->pitch = pitch;
> +	args->size = PAGE_ALIGN(args->pitch * args->height);
> +	vs_obj = vs_gem_create_with_handle(dev, file, args->size,
> +					   &args->handle);
> +	return PTR_ERR_OR_ZERO(vs_obj);
> +}
> +
> +struct drm_gem_object *
> +vs_gem_prime_import_sg_table(struct drm_device *dev,
> +			     struct dma_buf_attachment *attach,
> +			     struct sg_table *sgt)
> +{
> +	struct vs_gem_object *vs_obj;
> +	int npages;
> +	int ret;
> +	struct scatterlist *s;
> +	u32 i;
> +	dma_addr_t expected;
> +	size_t size = attach->dmabuf->size;
> +
> +	size = PAGE_ALIGN(size);
> +
> +	vs_obj = vs_gem_alloc_object(dev, size);
> +	if (IS_ERR(vs_obj))
> +		return ERR_CAST(vs_obj);
> +
> +	expected = sg_dma_address(sgt->sgl);
> +	for_each_sg(sgt->sgl, s, sgt->nents, i) {
> +		if (sg_dma_address(s) != expected) {
> +			DRM_ERROR("sg_table is not contiguous");
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +		if (sg_dma_len(s) & (PAGE_SIZE - 1)) {
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +		if (i == 0)
> +			vs_obj->iova = sg_dma_address(s);
> +		expected = sg_dma_address(s) + sg_dma_len(s);
> +	}
> +
> +	vs_obj->base.dma_addr = sg_dma_address(sgt->sgl);
> +
> +	npages = vs_obj->base.base.size >> PAGE_SHIFT;
> +	vs_obj->pages = kvmalloc_array(npages, sizeof(struct page *),
> +				       GFP_KERNEL);
> +	if (!vs_obj->pages) {
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	ret = drm_prime_sg_to_page_array(sgt, vs_obj->pages, npages);
> +	if (ret)
> +		goto err_free_page;
> +
> +	vs_obj->base.sgt = sgt;
> +
> +	return &vs_obj->base.base;
> +
> +err_free_page:
> +	kvfree(vs_obj->pages);
> +err:
> +	vs_gem_free_object(&vs_obj->base.base);
> +
> +	return ERR_PTR(ret);
> +}
> diff --git a/drivers/gpu/drm/verisilicon/vs_gem.h b/drivers/gpu/drm/verisilicon/vs_gem.h
> new file mode 100644
> index 000000000..d9ff6d23b
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_gem.h
> @@ -0,0 +1,50 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#ifndef __VS_GEM_H__
> +#define __VS_GEM_H__
> +
> +#include <linux/dma-buf.h>
> +
> +#include <drm/drm_gem.h>
> +#include <drm/drm_gem_dma_helper.h>
> +#include <drm/drm_prime.h>
> +
> +#include "vs_drv.h"
> +/*
> + *
> + * @base: drm_gem_dma_object.
> + * @cookie: cookie returned by dma_alloc_attrs
> + *	- not kernel virtual address with DMA_ATTR_NO_KERNEL_MAPPING
> + * @dma_attrs: attribute for DMA API
> + * @get_pages: flag for manually applying for non-contiguous memory.
> + * @pages: Array of backing pages.
> + *
> + */
> +struct vs_gem_object {
> +	struct drm_gem_dma_object	base;
> +	void			*cookie;
> +	u32				iova;
> +	unsigned long	dma_attrs;
> +	bool			get_pages;
> +	struct page		**pages;
> +};
> +
> +static inline struct vs_gem_object *
> +to_vs_gem_object(const struct drm_gem_object *bo)
> +{
> +	return container_of(to_drm_gem_dma_obj(bo), struct vs_gem_object, base);
> +}
> +
> +int vs_gem_dumb_create(struct drm_file *file_priv,
> +		       struct drm_device *drm,
> +		       struct drm_mode_create_dumb *args);
> +
> +struct drm_gem_object *
> +vs_gem_prime_import_sg_table(struct drm_device *dev,
> +			     struct dma_buf_attachment *attach,
> +			     struct sg_table *sgt);
> +
> +#endif /* __VS_GEM_H__ */
> diff --git a/drivers/gpu/drm/verisilicon/vs_modeset.c b/drivers/gpu/drm/verisilicon/vs_modeset.c
> new file mode 100644
> index 000000000..cd0bdf530
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_modeset.c
> @@ -0,0 +1,92 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/version.h>
> +
> +#include <drm/drm_damage_helper.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_fourcc.h>
> +#include <drm/drm_framebuffer.h>
> +#include <drm/drm_gem.h>
> +#include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_dma_helper.h>
> +
> +#include "vs_modeset.h"
> +#include "vs_gem.h"
> +
> +#define fourcc_mod_vs_get_type(val) \
> +	(((val) & DRM_FORMAT_MOD_VS_TYPE_MASK) >> 54)
> +
> +struct vs_gem_object *vs_fb_get_gem_obj(struct drm_framebuffer *fb,
> +					unsigned char plane)
> +{
> +	if (plane > DRM_FORMAT_MAX_PLANES)
> +		return NULL;
> +
> +	return to_vs_gem_object(fb->obj[plane]);
> +}
> +
> +static const struct drm_format_info vs_formats[] = {
> +	{.format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .char_per_block = { 20, 40, 0 },
> +	 .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true},
> +	{.format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .char_per_block = { 20, 20, 20 },
> +	 .block_w = { 4, 4, 4 }, .block_h = { 4, 4, 4 }, .hsub = 1, .vsub = 1, .is_yuv = true},
> +};
> +
> +static const struct drm_format_info *
> +vs_lookup_format_info(const struct drm_format_info formats[],
> +		      int num_formats, u32 format)
> +{
> +	int i;
> +
> +	for (i = 0; i < num_formats; i++) {
> +		if (formats[i].format == format)
> +			return &formats[i];
> +	}
> +
> +	return NULL;
> +}
> +
> +static const struct drm_format_info *
> +vs_get_format_info(const struct drm_mode_fb_cmd2 *cmd)
> +{
> +	if (fourcc_mod_vs_get_type(cmd->modifier[0]) ==
> +		DRM_FORMAT_MOD_VS_TYPE_CUSTOM_10BIT)
> +		return vs_lookup_format_info(vs_formats, ARRAY_SIZE(vs_formats),
> +									 cmd->pixel_format);
> +	else
> +		return NULL;
> +}
> +
> +static const struct drm_mode_config_funcs vs_mode_config_funcs = {
> +	.fb_create			 = drm_gem_fb_create,
> +	.get_format_info	 = vs_get_format_info,
> +	.output_poll_changed = drm_fb_helper_output_poll_changed,
> +	.atomic_check		 = drm_atomic_helper_check,
> +	.atomic_commit		 = drm_atomic_helper_commit,
> +};
> +
> +static struct drm_mode_config_helper_funcs vs_mode_config_helpers = {
> +	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
> +};
> +
> +void vs_mode_config_init(struct drm_device *dev)
> +{
> +	drm_mode_config_init(dev);
> +	dev->mode_config.fb_modifiers_not_supported = false;
> +
> +	if (dev->mode_config.max_width == 0 ||
> +	    dev->mode_config.max_height == 0) {
Not sure if the 'if' is really needed .
> +		dev->mode_config.min_width  = 0;
> +		dev->mode_config.min_height = 0;
> +		dev->mode_config.max_width  = 4096;
> +		dev->mode_config.max_height = 4096;
> +	}
> +	dev->mode_config.funcs = &vs_mode_config_funcs;
> +	dev->mode_config.helper_private = &vs_mode_config_helpers;
> +}
> diff --git a/drivers/gpu/drm/verisilicon/vs_modeset.h b/drivers/gpu/drm/verisilicon/vs_modeset.h
> new file mode 100644
> index 000000000..2e1f04a8a
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_modeset.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#ifndef __VS_FB_H__
> +#define __VS_FB_H__
> +
> +struct vs_gem_object *vs_fb_get_gem_obj(struct drm_framebuffer *fb,
> +					unsigned char plane);
> +
> +void vs_mode_config_init(struct drm_device *dev);
> +#endif /* __VS_FB_H__ */
> diff --git a/include/uapi/drm/vs_drm.h b/include/uapi/drm/vs_drm.h
> new file mode 100644
> index 000000000..96b7fc95d
> --- /dev/null
> +++ b/include/uapi/drm/vs_drm.h
> @@ -0,0 +1,50 @@
> +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> +/*
> + * Copyright (C) 2020 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#ifndef __VS_DRM_H__
> +#define __VS_DRM_H__
> +
> +#include "drm.h"
> +
> +enum drm_vs_degamma_mode {
> +	VS_DEGAMMA_DISABLE = 0,
> +	VS_DEGAMMA_BT709 = 1,
> +	VS_DEGAMMA_BT2020 = 2,
> +};
> +
> +enum drm_vs_sync_dc_mode {
> +	VS_SINGLE_DC = 0,
> +	VS_MULTI_DC_PRIMARY = 1,
> +	VS_MULTI_DC_SECONDARY = 2,
> +};
> +
> +enum drm_vs_mmu_prefetch_mode {
> +	VS_MMU_PREFETCH_DISABLE = 0,
> +	VS_MMU_PREFETCH_ENABLE = 1,
> +};
> +
> +struct drm_vs_watermark {
> +	__u32 watermark;
> +	__u8 qos_low;
> +	__u8 qos_high;
> +};
> +
> +struct drm_vs_color_mgmt {
> +	__u32 colorkey;
> +	__u32 colorkey_high;
> +	__u32 clear_value;
> +	bool  clear_enable;
> +	bool  transparency;
> +};
> +
> +struct drm_vs_roi {
> +	bool enable;
> +	__u16 roi_x;
> +	__u16 roi_y;
> +	__u16 roi_w;
> +	__u16 roi_h;
> +};
> +
> +#endif /* __VS_DRM_H__ */