[v4,3/5] staging: Introduce NVIDIA Tegra video decoder driver

Message ID 1a3798f337c0097e67d70226ae3ba665fd9156c2.1508448293.git.digetx@gmail.com
State New
Headers show
Series
  • NVIDIA Tegra20 video decoder driver
Related show

Commit Message

Dmitry Osipenko Oct. 19, 2017, 9:34 p.m.
NVIDIA Tegra20/30/114/124/132 SoC's have video decoder engine that
supports standard set of video formats like H.264 / MPEG-4 / WMV / VC1.
Currently implemented decoding of CAVLC H.264 on Tegra20 only.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/staging/Kconfig            |    2 +
 drivers/staging/Makefile           |    1 +
 drivers/staging/tegra-vde/Kconfig  |    7 +
 drivers/staging/tegra-vde/Makefile |    1 +
 drivers/staging/tegra-vde/TODO     |    5 +
 drivers/staging/tegra-vde/uapi.h   |  101 +++
 drivers/staging/tegra-vde/vde.c    | 1209 ++++++++++++++++++++++++++++++++++++
 7 files changed, 1326 insertions(+)
 create mode 100644 drivers/staging/tegra-vde/Kconfig
 create mode 100644 drivers/staging/tegra-vde/Makefile
 create mode 100644 drivers/staging/tegra-vde/TODO
 create mode 100644 drivers/staging/tegra-vde/uapi.h
 create mode 100644 drivers/staging/tegra-vde/vde.c

Comments

Vladimir Zapolskiy Nov. 11, 2017, 2:06 p.m. | #1
Hi Dmitry,

I'll add just a couple of minor comments, in general the code looks
very good.

On 10/20/2017 12:34 AM, Dmitry Osipenko wrote:
> NVIDIA Tegra20/30/114/124/132 SoC's have video decoder engine that
> supports standard set of video formats like H.264 / MPEG-4 / WMV / VC1.
> Currently implemented decoding of CAVLC H.264 on Tegra20 only.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

[snip]

> +++ b/drivers/staging/tegra-vde/uapi.h
> @@ -0,0 +1,101 @@
> +/*
> + * Copyright (C) 2016-2017 Dmitry Osipenko <digetx@gmail.com>
> + * All Rights Reserved.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.

From the specified MODULE_LICENSE("GPL") I'd rather expect to see a reference
to GPLv2+ license in the header, and here the text resembles MIT license only.

I understand that it is a UAPI header file and it may happen that different
rules are applied to this kind of sources, hopefully Greg can give the right
directions.

In general you may avoid the headache with the custom UAPI, if you reuse
V4L2 interfaces, if I remember correctly drivers/media/platform/coda does it.
Also from my point of view the custom UAPI is the only reason why the driver
is pushed to the staging folder.

[snip]

> +struct tegra_vde {
> +	void __iomem *sxe;
> +	void __iomem *bsev;
> +	void __iomem *mbe;
> +	void __iomem *ppe;
> +	void __iomem *mce;
> +	void __iomem *tfe;
> +	void __iomem *ppb;
> +	void __iomem *vdma;
> +	void __iomem *frameid;

Please find a comment in tegra_vde_probe() function regarding
devm_ioremap_resource() calls.

> +	struct mutex lock;
> +	struct miscdevice miscdev;
> +	struct reset_control *rst;
> +	struct gen_pool *iram_pool;
> +	struct completion decode_completion;
> +	struct clk *clk;
> +	dma_addr_t iram_lists_addr;
> +	u32 *iram;
> +};

[snip]

> +static int tegra_vde_wait_bsev(struct tegra_vde *vde, bool wait_dma)
> +{
> +	struct device *dev = vde->miscdev.parent;
> +	u32 value;
> +	int err;
> +
> +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
> +					 !(value & BIT(2)), 1, 100);
> +	if (err) {
> +		dev_err(dev, "BSEV unknown bit timeout\n");
> +		return err;
> +	}
> +
> +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
> +					 (value & BSE_ICMDQUE_EMPTY), 1, 100);
> +	if (err) {
> +		dev_err(dev, "BSEV ICMDQUE flush timeout\n");
> +		return err;
> +	}
> +
> +	if (!wait_dma)
> +		return 0;
> +
> +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
> +					 !(value & BSE_DMA_BUSY), 1, 100);
> +	if (err) {
> +		dev_err(dev, "BSEV DMA timeout\n");
> +		return err;
> +	}
> +
> +	return 0;

	if (err)
		dev_err(dev, "BSEV DMA timeout\n");

	return err;

is two lines shorter.

> +}
> +

[snip]

> +static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
> +					struct video_frame *frame,
> +					struct tegra_vde_h264_frame *source,
> +					enum dma_data_direction dma_dir,
> +					bool baseline_profile,
> +					size_t csize)
> +{
> +	int err;
> +
> +	err = tegra_vde_attach_dmabuf(dev, source->y_fd,
> +				      source->y_offset, csize * 4,
> +				      &frame->y_dmabuf_attachment,
> +				      &frame->y_addr,
> +				      &frame->y_sgt,
> +				      NULL, dma_dir);
> +	if (err)
> +		return err;
> +
> +	err = tegra_vde_attach_dmabuf(dev, source->cb_fd,
> +				      source->cb_offset, csize,
> +				      &frame->cb_dmabuf_attachment,
> +				      &frame->cb_addr,
> +				      &frame->cb_sgt,
> +				      NULL, dma_dir);
> +	if (err)
> +		goto err_release_y;
> +
> +	err = tegra_vde_attach_dmabuf(dev, source->cr_fd,
> +				      source->cr_offset, csize,
> +				      &frame->cr_dmabuf_attachment,
> +				      &frame->cr_addr,
> +				      &frame->cr_sgt,
> +				      NULL, dma_dir);
> +	if (err)
> +		goto err_release_cb;
> +
> +	if (baseline_profile) {
> +		frame->aux_addr = 0xF4DEAD00;
> +	} else {

I would rather suggest to do

	if (baseline_profile) {
		frame->aux_addr = 0xF4DEAD00;
		return 0;
	}

and remove indentation from the code block below.

> +		err = tegra_vde_attach_dmabuf(dev, source->aux_fd,
> +					      source->aux_offset, csize,
> +					      &frame->aux_dmabuf_attachment,
> +					      &frame->aux_addr,
> +					      &frame->aux_sgt,
> +					      NULL, dma_dir);
> +		if (err)
> +			goto err_release_cr;
> +	}
> +
> +	return 0;

	if (!err)
		return 0;

and then remove a check above.

> +
> +err_release_cr:
> +	tegra_vde_detach_and_put_dmabuf(frame->cr_dmabuf_attachment,
> +					frame->cr_sgt, dma_dir);
> +err_release_cb:
> +	tegra_vde_detach_and_put_dmabuf(frame->cb_dmabuf_attachment,
> +					frame->cb_sgt, dma_dir);
> +err_release_y:
> +	tegra_vde_detach_and_put_dmabuf(frame->y_dmabuf_attachment,
> +					frame->y_sgt, dma_dir);
> +
> +	return err;
> +}

[snip]

> +static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> +				       unsigned long vaddr)
> +{
> +	struct device *dev = vde->miscdev.parent;
> +	struct tegra_vde_h264_decoder_ctx ctx;
> +	struct tegra_vde_h264_frame __user *frames_user;
> +	struct tegra_vde_h264_frame *frames;
> +	struct video_frame *dpb_frames;
> +	struct dma_buf_attachment *bitstream_data_dmabuf_attachment;
> +	struct sg_table *bitstream_sgt;
> +	enum dma_data_direction dma_dir;
> +	dma_addr_t bitstream_data_addr;
> +	dma_addr_t bsev_ptr;
> +	size_t bitstream_data_size;
> +	unsigned int macroblocks_nb;
> +	unsigned int read_bytes;
> +	unsigned int i = 0;
> +	bool timeout;
> +	int ret;
> +
> +	if (copy_from_user(&ctx, (void __user *)vaddr, sizeof(ctx)))
> +		return -EFAULT;
> +
> +	ret = tegra_vde_validate_h264_ctx(dev, &ctx);
> +	if (ret)
> +		return -EINVAL;

Or "return ret".

> +
> +	ret = tegra_vde_attach_dmabuf(dev, ctx.bitstream_data_fd,
> +				      ctx.bitstream_data_offset, 0,
> +				      &bitstream_data_dmabuf_attachment,
> +				      &bitstream_data_addr,
> +				      &bitstream_sgt,
> +				      &bitstream_data_size,
> +				      DMA_TO_DEVICE);
> +	if (ret)
> +		return ret;
> +
> +	dpb_frames = kcalloc(ctx.dpb_frames_nb, sizeof(*dpb_frames),
> +			     GFP_KERNEL);
> +	if (!dpb_frames) {
> +		ret = -ENOMEM;
> +		goto err_release_bitstream_dmabuf;
> +	}
> +
> +	macroblocks_nb = ctx.pic_width_in_mbs * ctx.pic_height_in_mbs;
> +	frames_user = u64_to_user_ptr(ctx.dpb_frames_ptr);
> +
> +	frames = kmalloc_array(ctx.dpb_frames_nb, sizeof(*frames), GFP_KERNEL);
> +	if (!frames) {
> +		ret = -ENOMEM;
> +		goto err_release_dpb_frames;
> +	}
> +
> +	if (copy_from_user(frames, frames_user,
> +			   ctx.dpb_frames_nb * sizeof(*frames))) {
> +		ret = -EFAULT;
> +		goto free_frames;

It could be

	ret = -EFAULT;
	kfree(frames);
	goto err_release_dpb_frames;

> +	}
> +
> +	for (i = 0; i < ctx.dpb_frames_nb; i++) {
> +		ret = tegra_vde_validate_frame(dev, &frames[i]);
> +		if (ret)
> +			goto free_frames;

It could be

	if (ret)
		break;

or
	if (ret) {
		kfree(frames);
		goto err_release_dpb_frames;
	}

> +
> +		dpb_frames[i].flags = frames[i].flags;
> +		dpb_frames[i].frame_num = frames[i].frame_num;
> +
> +		dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
> +
> +		ret = tegra_vde_attach_dmabufs_to_frame(dev, &dpb_frames[i],
> +							&frames[i], dma_dir,
> +							ctx.baseline_profile,
> +							macroblocks_nb * 64);
> +		if (ret)
> +			goto free_frames;

It could be

	if (ret)
		break;

or

	if (ret) {
		kfree(frames);
		goto err_release_dpb_frames;
	}

I don't strictly ask for the changes, but in my opinion less indentation
is better.

> +	}
> +
> +free_frames:
> +	kfree(frames);
> +
> +	if (ret)
> +		goto err_release_dpb_frames;

If you select an option with 'kfree' in all three cases above, then
it is possible to remove 'kfree' here, remove the check and remove
a goto label.

It's up to you to decide, which version is better.

[snip]

> +
> +static int tegra_vde_runtime_resume(struct device *dev)
> +{
> +	struct tegra_vde *vde = dev_get_drvdata(dev);
> +	int err;
> +
> +	err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_VDEC,
> +						vde->clk, vde->rst);
> +	if (err) {
> +		dev_err(dev, "Failed to power up HW : %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;

	if (err)
		dev_err(dev, "Failed to power up HW : %d\n", err);

	return err;

saves 2 lines of code.

> +}
> +
> +static int tegra_vde_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct resource *regs;
> +	struct tegra_vde *vde;
> +	int irq, err;
> +
> +	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
> +	if (!vde)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, vde);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sxe");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->sxe = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->sxe))
> +		return PTR_ERR(vde->sxe);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "bsev");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->bsev = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->bsev))
> +		return PTR_ERR(vde->bsev);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mbe");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->mbe = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->mbe))
> +		return PTR_ERR(vde->mbe);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ppe");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->ppe = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->ppe))
> +		return PTR_ERR(vde->ppe);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mce");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->mce = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->mce))
> +		return PTR_ERR(vde->mce);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "tfe");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->tfe = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->tfe))
> +		return PTR_ERR(vde->tfe);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ppb");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->ppb = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->ppb))
> +		return PTR_ERR(vde->ppb);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vdma");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->vdma = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->vdma))
> +		return PTR_ERR(vde->vdma);
> +
> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "frameid");
> +	if (!regs)
> +		return -ENODEV;
> +
> +	vde->frameid = devm_ioremap_resource(dev, regs);
> +	if (IS_ERR(vde->frameid))
> +		return PTR_ERR(vde->frameid);

This is just my personal opinion on which I do not insist, however I'd like
to share it, a single memory region described in DTB (and the same single
region mapped once) and subregion offsets in the driver may be more preferable.

If I remember correctly that was found in the previous versions of the driver,
the new scheme might be preferred only if the offsets are different in different
Tegra VDE IPs, but even in the latter case it might be better to handle the
difference inside the driver.

> +
> +	vde->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(vde->clk)) {
> +		err = PTR_ERR(vde->clk);
> +		dev_err(dev, "Could not get VDE clk %d\n", err);
> +		return err;
> +	}
> +
> +	vde->rst = devm_reset_control_get(dev, NULL);
> +	if (IS_ERR(vde->rst)) {
> +		err = PTR_ERR(vde->rst);
> +		dev_err(dev, "Could not get VDE reset %d\n", err);
> +		return err;
> +	}
> +
> +	irq = platform_get_irq_byname(pdev, "sync-token");
> +	if (irq < 0)
> +		return irq;
> +
> +	err = devm_request_irq(dev, irq, tegra_vde_isr, 0,
> +			       dev_name(dev), vde);
> +	if (err) {
> +		dev_err(dev, "Could not request IRQ %d\n", err);
> +		return err;
> +	}
> +
> +	vde->iram_pool = of_gen_pool_get(dev->of_node, "iram", 0);
> +	if (!vde->iram_pool) {
> +		dev_err(dev, "Could not get IRAM pool\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	vde->iram = gen_pool_dma_alloc(vde->iram_pool, 0x3FC00,

The size of the pool should not be hardcoded, it is expected to be
obtained from the device tree:

	gen_pool_size(vde->iram_pool)

> +				       &vde->iram_lists_addr);
> +	if (!vde->iram) {
> +		dev_err(dev, "Could not reserve IRAM\n");
> +		return -ENOMEM;
> +	}
> +
> +	mutex_init(&vde->lock);
> +	init_completion(&vde->decode_completion);
> +
> +	vde->miscdev.minor = MISC_DYNAMIC_MINOR;
> +	vde->miscdev.name = "tegra_vde";
> +	vde->miscdev.fops = &tegra_vde_fops;
> +	vde->miscdev.parent = dev;
> +
> +	err = misc_register(&vde->miscdev);
> +	if (err) {
> +		dev_err(dev, "Failed to register misc device: %d\n", err);
> +		goto err_gen_free;
> +	}
> +
> +	pm_runtime_enable(dev);
> +	pm_runtime_use_autosuspend(dev);
> +	pm_runtime_set_autosuspend_delay(dev, 300);
> +
> +	if (!pm_runtime_enabled(dev)) {
> +		err = tegra_vde_runtime_resume(dev);
> +		if (err)
> +			goto err_misc_unreg;
> +	}
> +
> +	return 0;
> +
> +err_misc_unreg:
> +	misc_deregister(&vde->miscdev);
> +
> +err_gen_free:
> +	gen_pool_free(vde->iram_pool,
> +		      (unsigned long)vde->iram, 0x3FC00);

See a comment above.

> +
> +	return err;
> +}
> +
> +static int tegra_vde_remove(struct platform_device *pdev)
> +{
> +	struct tegra_vde *vde = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	int err;
> +
> +	if (!pm_runtime_enabled(dev)) {
> +		err = tegra_vde_runtime_suspend(dev);
> +		if (err)
> +			return err;
> +	}
> +
> +	pm_runtime_dont_use_autosuspend(dev);
> +	pm_runtime_disable(dev);
> +
> +	misc_deregister(&vde->miscdev);
> +
> +	gen_pool_free(vde->iram_pool,
> +		      (unsigned long)vde->iram, 0x3FC00);

See a comment above.

> +
> +	return 0;
> +}
> +

[snip]

> +
> +MODULE_DESCRIPTION("NVIDIA Tegra20 Video Decoder driver");
> +MODULE_AUTHOR("Dmitry Osipenko");

Please add your email here, then if you are not a maintainer (and by
the way please consider to add your name to the MAINTAINERS file),
you'll get a higher chance to receive updates in the future.

> +MODULE_LICENSE("GPL");
> 

--
With best wishes,
Vladimir
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Dmitry Osipenko Nov. 12, 2017, 4:17 p.m. | #2
On 11.11.2017 17:06, Vladimir Zapolskiy wrote:
> Hi Dmitry,
> 
> I'll add just a couple of minor comments, in general the code looks
> very good.
> 

Thank you very much for the review!

> On 10/20/2017 12:34 AM, Dmitry Osipenko wrote:
>> NVIDIA Tegra20/30/114/124/132 SoC's have video decoder engine that
>> supports standard set of video formats like H.264 / MPEG-4 / WMV / VC1.
>> Currently implemented decoding of CAVLC H.264 on Tegra20 only.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> 
> [snip]
> 
>> +++ b/drivers/staging/tegra-vde/uapi.h
>> @@ -0,0 +1,101 @@
>> +/*
>> + * Copyright (C) 2016-2017 Dmitry Osipenko <digetx@gmail.com>
>> + * All Rights Reserved.
>> + *
>> + * Permission is hereby granted, free of charge, to any person obtaining a
>> + * copy of this software and associated documentation files (the "Software"),
>> + * to deal in the Software without restriction, including without limitation
>> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
>> + * and/or sell copies of the Software, and to permit persons to whom the
>> + * Software is furnished to do so, subject to the following conditions:
>> + *
>> + * The above copyright notice and this permission notice (including the next
>> + * paragraph) shall be included in all copies or substantial portions of the
>> + * Software.
>> + *
>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
>> + * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
>> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
>> + * OTHER DEALINGS IN THE SOFTWARE.
> 
> From the specified MODULE_LICENSE("GPL") I'd rather expect to see a reference
> to GPLv2+ license in the header, and here the text resembles MIT license only.
> 
> I understand that it is a UAPI header file and it may happen that different
> rules are applied to this kind of sources, hopefully Greg can give the right
> directions.

Indeed, probably I copied the license text from some other UAPI header without
putting much thought. Will change it to GPL, thanks.

> 
> In general you may avoid the headache with the custom UAPI, if you reuse
> V4L2 interfaces, if I remember correctly drivers/media/platform/coda does it.
> Also from my point of view the custom UAPI is the only reason why the driver
> is pushed to the staging folder.

Thanks for the pointer. I see that coda driver does some raw bitstream parsing
in the driver, which is a bit icky, but probably is a good enough variant. I'll
take a closer look at implementing V4L interface at some point later, meanwhile
custom UAPI + VDPAU userspace serves us pretty well.

> 
> [snip]
> 
>> +struct tegra_vde {
>> +	void __iomem *sxe;
>> +	void __iomem *bsev;
>> +	void __iomem *mbe;
>> +	void __iomem *ppe;
>> +	void __iomem *mce;
>> +	void __iomem *tfe;
>> +	void __iomem *ppb;
>> +	void __iomem *vdma;
>> +	void __iomem *frameid;
> 
> Please find a comment in tegra_vde_probe() function regarding
> devm_ioremap_resource() calls.
> 
>> +	struct mutex lock;
>> +	struct miscdevice miscdev;
>> +	struct reset_control *rst;
>> +	struct gen_pool *iram_pool;
>> +	struct completion decode_completion;
>> +	struct clk *clk;
>> +	dma_addr_t iram_lists_addr;
>> +	u32 *iram;
>> +};
> 
> [snip]
> 
>> +static int tegra_vde_wait_bsev(struct tegra_vde *vde, bool wait_dma)
>> +{
>> +	struct device *dev = vde->miscdev.parent;
>> +	u32 value;
>> +	int err;
>> +
>> +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
>> +					 !(value & BIT(2)), 1, 100);
>> +	if (err) {
>> +		dev_err(dev, "BSEV unknown bit timeout\n");
>> +		return err;
>> +	}
>> +
>> +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
>> +					 (value & BSE_ICMDQUE_EMPTY), 1, 100);
>> +	if (err) {
>> +		dev_err(dev, "BSEV ICMDQUE flush timeout\n");
>> +		return err;
>> +	}
>> +
>> +	if (!wait_dma)
>> +		return 0;
>> +
>> +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
>> +					 !(value & BSE_DMA_BUSY), 1, 100);
>> +	if (err) {
>> +		dev_err(dev, "BSEV DMA timeout\n");
>> +		return err;
>> +	}
>> +
>> +	return 0;
> 
> 	if (err)
> 		dev_err(dev, "BSEV DMA timeout\n");
> 
> 	return err;
> 
> is two lines shorter.
> 

Thanks for the suggestion. I think that consistency in the code is a bit more
preferable, so I'd prefer to stick with the original variant here.

>> +}
>> +
> 
> [snip]
> 
>> +static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
>> +					struct video_frame *frame,
>> +					struct tegra_vde_h264_frame *source,
>> +					enum dma_data_direction dma_dir,
>> +					bool baseline_profile,
>> +					size_t csize)
>> +{
>> +	int err;
>> +
>> +	err = tegra_vde_attach_dmabuf(dev, source->y_fd,
>> +				      source->y_offset, csize * 4,
>> +				      &frame->y_dmabuf_attachment,
>> +				      &frame->y_addr,
>> +				      &frame->y_sgt,
>> +				      NULL, dma_dir);
>> +	if (err)
>> +		return err;
>> +
>> +	err = tegra_vde_attach_dmabuf(dev, source->cb_fd,
>> +				      source->cb_offset, csize,
>> +				      &frame->cb_dmabuf_attachment,
>> +				      &frame->cb_addr,
>> +				      &frame->cb_sgt,
>> +				      NULL, dma_dir);
>> +	if (err)
>> +		goto err_release_y;
>> +
>> +	err = tegra_vde_attach_dmabuf(dev, source->cr_fd,
>> +				      source->cr_offset, csize,
>> +				      &frame->cr_dmabuf_attachment,
>> +				      &frame->cr_addr,
>> +				      &frame->cr_sgt,
>> +				      NULL, dma_dir);
>> +	if (err)
>> +		goto err_release_cb;
>> +
>> +	if (baseline_profile) {
>> +		frame->aux_addr = 0xF4DEAD00;
>> +	} else {
> 
> I would rather suggest to do
> 
> 	if (baseline_profile) {
> 		frame->aux_addr = 0xF4DEAD00;
> 		return 0;
> 	}
> 
> and remove indentation from the code block below.
> 

Good suggestion, thanks.

>> +		err = tegra_vde_attach_dmabuf(dev, source->aux_fd,
>> +					      source->aux_offset, csize,
>> +					      &frame->aux_dmabuf_attachment,
>> +					      &frame->aux_addr,
>> +					      &frame->aux_sgt,
>> +					      NULL, dma_dir);
>> +		if (err)
>> +			goto err_release_cr;
>> +	}
>> +
>> +	return 0;
> 
> 	if (!err)
> 		return 0;
> 
> and then remove a check above.
> 

I'd prefer to keep 'goto' for the consistency.

>> +
>> +err_release_cr:
>> +	tegra_vde_detach_and_put_dmabuf(frame->cr_dmabuf_attachment,
>> +					frame->cr_sgt, dma_dir);
>> +err_release_cb:
>> +	tegra_vde_detach_and_put_dmabuf(frame->cb_dmabuf_attachment,
>> +					frame->cb_sgt, dma_dir);
>> +err_release_y:
>> +	tegra_vde_detach_and_put_dmabuf(frame->y_dmabuf_attachment,
>> +					frame->y_sgt, dma_dir);
>> +
>> +	return err;
>> +}
> 
> [snip]
> 
>> +static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>> +				       unsigned long vaddr)
>> +{
>> +	struct device *dev = vde->miscdev.parent;
>> +	struct tegra_vde_h264_decoder_ctx ctx;
>> +	struct tegra_vde_h264_frame __user *frames_user;
>> +	struct tegra_vde_h264_frame *frames;
>> +	struct video_frame *dpb_frames;
>> +	struct dma_buf_attachment *bitstream_data_dmabuf_attachment;
>> +	struct sg_table *bitstream_sgt;
>> +	enum dma_data_direction dma_dir;
>> +	dma_addr_t bitstream_data_addr;
>> +	dma_addr_t bsev_ptr;
>> +	size_t bitstream_data_size;
>> +	unsigned int macroblocks_nb;
>> +	unsigned int read_bytes;
>> +	unsigned int i = 0;
>> +	bool timeout;
>> +	int ret;
>> +
>> +	if (copy_from_user(&ctx, (void __user *)vaddr, sizeof(ctx)))
>> +		return -EFAULT;
>> +
>> +	ret = tegra_vde_validate_h264_ctx(dev, &ctx);
>> +	if (ret)
>> +		return -EINVAL;
> 
> Or "return ret".
> 

Good catch.

>> +
>> +	ret = tegra_vde_attach_dmabuf(dev, ctx.bitstream_data_fd,
>> +				      ctx.bitstream_data_offset, 0,
>> +				      &bitstream_data_dmabuf_attachment,
>> +				      &bitstream_data_addr,
>> +				      &bitstream_sgt,
>> +				      &bitstream_data_size,
>> +				      DMA_TO_DEVICE);
>> +	if (ret)
>> +		return ret;
>> +
>> +	dpb_frames = kcalloc(ctx.dpb_frames_nb, sizeof(*dpb_frames),
>> +			     GFP_KERNEL);
>> +	if (!dpb_frames) {
>> +		ret = -ENOMEM;
>> +		goto err_release_bitstream_dmabuf;
>> +	}
>> +
>> +	macroblocks_nb = ctx.pic_width_in_mbs * ctx.pic_height_in_mbs;
>> +	frames_user = u64_to_user_ptr(ctx.dpb_frames_ptr);
>> +
>> +	frames = kmalloc_array(ctx.dpb_frames_nb, sizeof(*frames), GFP_KERNEL);
>> +	if (!frames) {
>> +		ret = -ENOMEM;
>> +		goto err_release_dpb_frames;
>> +	}
>> +
>> +	if (copy_from_user(frames, frames_user,
>> +			   ctx.dpb_frames_nb * sizeof(*frames))) {
>> +		ret = -EFAULT;
>> +		goto free_frames;
> 
> It could be
> 
> 	ret = -EFAULT;
> 	kfree(frames);
> 	goto err_release_dpb_frames;
> 

That indeed should be a bit cleaner, thanks. I'll also add/use a new 'goto
err_free_dpb_frames'.

>> +	}
>> +
>> +	for (i = 0; i < ctx.dpb_frames_nb; i++) {
>> +		ret = tegra_vde_validate_frame(dev, &frames[i]);
>> +		if (ret)
>> +			goto free_frames;
> 
> It could be
> 
> 	if (ret)
> 		break;
> 
> or
> 	if (ret) {
> 		kfree(frames);
> 		goto err_release_dpb_frames;
> 	}
> 
>> +
>> +		dpb_frames[i].flags = frames[i].flags;
>> +		dpb_frames[i].frame_num = frames[i].frame_num;
>> +
>> +		dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
>> +
>> +		ret = tegra_vde_attach_dmabufs_to_frame(dev, &dpb_frames[i],
>> +							&frames[i], dma_dir,
>> +							ctx.baseline_profile,
>> +							macroblocks_nb * 64);
>> +		if (ret)
>> +			goto free_frames;
> 
> It could be
> 
> 	if (ret)
> 		break;
> 
> or
> 
> 	if (ret) {
> 		kfree(frames);
> 		goto err_release_dpb_frames;
> 	}
> 
> I don't strictly ask for the changes, but in my opinion less indentation
> is better.
> 
>> +	}
>> +
>> +free_frames:
>> +	kfree(frames);
>> +
>> +	if (ret)
>> +		goto err_release_dpb_frames;
> 
> If you select an option with 'kfree' in all three cases above, then
> it is possible to remove 'kfree' here, remove the check and remove
> a goto label.
> 
> It's up to you to decide, which version is better.
> 

The 'break' looks like a good variant, thanks. But we need to keep kfree(frames)
after the loop anyway because 'frames' is a temporary allocation and it isn't
free'd later.

> [snip]
> 
>> +
>> +static int tegra_vde_runtime_resume(struct device *dev)
>> +{
>> +	struct tegra_vde *vde = dev_get_drvdata(dev);
>> +	int err;
>> +
>> +	err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_VDEC,
>> +						vde->clk, vde->rst);
>> +	if (err) {
>> +		dev_err(dev, "Failed to power up HW : %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	return 0;
> 
> 	if (err)
> 		dev_err(dev, "Failed to power up HW : %d\n", err);
> 
> 	return err;
> 
> saves 2 lines of code.
> 

Yeah, but I'd prefer to keep up consistency.

>> +}
>> +
>> +static int tegra_vde_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct resource *regs;
>> +	struct tegra_vde *vde;
>> +	int irq, err;
>> +
>> +	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
>> +	if (!vde)
>> +		return -ENOMEM;
>> +
>> +	platform_set_drvdata(pdev, vde);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sxe");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->sxe = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->sxe))
>> +		return PTR_ERR(vde->sxe);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "bsev");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->bsev = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->bsev))
>> +		return PTR_ERR(vde->bsev);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mbe");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->mbe = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->mbe))
>> +		return PTR_ERR(vde->mbe);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ppe");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->ppe = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->ppe))
>> +		return PTR_ERR(vde->ppe);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mce");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->mce = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->mce))
>> +		return PTR_ERR(vde->mce);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "tfe");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->tfe = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->tfe))
>> +		return PTR_ERR(vde->tfe);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ppb");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->ppb = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->ppb))
>> +		return PTR_ERR(vde->ppb);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vdma");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->vdma = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->vdma))
>> +		return PTR_ERR(vde->vdma);
>> +
>> +	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "frameid");
>> +	if (!regs)
>> +		return -ENODEV;
>> +
>> +	vde->frameid = devm_ioremap_resource(dev, regs);
>> +	if (IS_ERR(vde->frameid))
>> +		return PTR_ERR(vde->frameid);
> 
> This is just my personal opinion on which I do not insist, however I'd like
> to share it, a single memory region described in DTB (and the same single
> region mapped once) and subregion offsets in the driver may be more preferable.
> 
> If I remember correctly that was found in the previous versions of the driver,
> the new scheme might be preferred only if the offsets are different in different
> Tegra VDE IPs, but even in the latter case it might be better to handle the
> difference inside the driver.
> 

I've very briefly mentioned that change in the cover-letter, the problem is that
BSEA (bitstream audio) and UCQ (unified commands queue) registers are placed in
between the VDE registers. In the reference manual, the VDE BSEA and UCQ are
drawn as a distinct blocks on the Block Diagram, I presume that VDE driver
shouldn't cover BSEA and UCQ. But if it will turn out that it should, I think it
wouldn't be a problem to make a unified MFD driver that covers all IP blocks.

>> +
>> +	vde->clk = devm_clk_get(dev, NULL);
>> +	if (IS_ERR(vde->clk)) {
>> +		err = PTR_ERR(vde->clk);
>> +		dev_err(dev, "Could not get VDE clk %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	vde->rst = devm_reset_control_get(dev, NULL);
>> +	if (IS_ERR(vde->rst)) {
>> +		err = PTR_ERR(vde->rst);
>> +		dev_err(dev, "Could not get VDE reset %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	irq = platform_get_irq_byname(pdev, "sync-token");
>> +	if (irq < 0)
>> +		return irq;
>> +
>> +	err = devm_request_irq(dev, irq, tegra_vde_isr, 0,
>> +			       dev_name(dev), vde);
>> +	if (err) {
>> +		dev_err(dev, "Could not request IRQ %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	vde->iram_pool = of_gen_pool_get(dev->of_node, "iram", 0);
>> +	if (!vde->iram_pool) {
>> +		dev_err(dev, "Could not get IRAM pool\n");
>> +		return -EPROBE_DEFER;
>> +	}
>> +
>> +	vde->iram = gen_pool_dma_alloc(vde->iram_pool, 0x3FC00,
> 
> The size of the pool should not be hardcoded, it is expected to be
> obtained from the device tree:
> 
> 	gen_pool_size(vde->iram_pool)
> 

Indeed, thanks.

>> +				       &vde->iram_lists_addr);
>> +	if (!vde->iram) {
>> +		dev_err(dev, "Could not reserve IRAM\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	mutex_init(&vde->lock);
>> +	init_completion(&vde->decode_completion);
>> +
>> +	vde->miscdev.minor = MISC_DYNAMIC_MINOR;
>> +	vde->miscdev.name = "tegra_vde";
>> +	vde->miscdev.fops = &tegra_vde_fops;
>> +	vde->miscdev.parent = dev;
>> +
>> +	err = misc_register(&vde->miscdev);
>> +	if (err) {
>> +		dev_err(dev, "Failed to register misc device: %d\n", err);
>> +		goto err_gen_free;
>> +	}
>> +
>> +	pm_runtime_enable(dev);
>> +	pm_runtime_use_autosuspend(dev);
>> +	pm_runtime_set_autosuspend_delay(dev, 300);
>> +
>> +	if (!pm_runtime_enabled(dev)) {
>> +		err = tegra_vde_runtime_resume(dev);
>> +		if (err)
>> +			goto err_misc_unreg;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_misc_unreg:
>> +	misc_deregister(&vde->miscdev);
>> +
>> +err_gen_free:
>> +	gen_pool_free(vde->iram_pool,
>> +		      (unsigned long)vde->iram, 0x3FC00);
> 
> See a comment above.
> 
>> +
>> +	return err;
>> +}
>> +
>> +static int tegra_vde_remove(struct platform_device *pdev)
>> +{
>> +	struct tegra_vde *vde = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	int err;
>> +
>> +	if (!pm_runtime_enabled(dev)) {
>> +		err = tegra_vde_runtime_suspend(dev);
>> +		if (err)
>> +			return err;
>> +	}
>> +
>> +	pm_runtime_dont_use_autosuspend(dev);
>> +	pm_runtime_disable(dev);
>> +
>> +	misc_deregister(&vde->miscdev);
>> +
>> +	gen_pool_free(vde->iram_pool,
>> +		      (unsigned long)vde->iram, 0x3FC00);
> 
> See a comment above.
> 
>> +
>> +	return 0;
>> +}
>> +
> 
> [snip]
> 
>> +
>> +MODULE_DESCRIPTION("NVIDIA Tegra20 Video Decoder driver");
>> +MODULE_AUTHOR("Dmitry Osipenko");
> 
> Please add your email here, then if you are not a maintainer (and by
> the way please consider to add your name to the MAINTAINERS file),
> you'll get a higher chance to receive updates in the future.
> 

Thank you for the suggestion, I'll add the email.

>> +MODULE_LICENSE("GPL");
>>

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Dan Carpenter Nov. 13, 2017, 8:16 a.m. | #3
On Sat, Nov 11, 2017 at 04:06:52PM +0200, Vladimir Zapolskiy wrote:
> > +	if (!wait_dma)
> > +		return 0;
> > +
> > +	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
> > +					 !(value & BSE_DMA_BUSY), 1, 100);
> > +	if (err) {
> > +		dev_err(dev, "BSEV DMA timeout\n");
> > +		return err;
> > +	}
> > +
> > +	return 0;
> 
> 	if (err)
> 		dev_err(dev, "BSEV DMA timeout\n");
> 
> 	return err;
> 
> is two lines shorter.
> 

This is fine, but just watch out because getting clever with a last if
statement is a common anti-pattern.  For example, you often see it where
people do success handling instead of failure handling.  And it leads
to static checker bugs, and makes the code slightly more subtle.

> > +		err = tegra_vde_attach_dmabuf(dev, source->aux_fd,
> > +					      source->aux_offset, csize,
> > +					      &frame->aux_dmabuf_attachment,
> > +					      &frame->aux_addr,
> > +					      &frame->aux_sgt,
> > +					      NULL, dma_dir);
> > +		if (err)
> > +			goto err_release_cr;
> > +	}
> > +
> > +	return 0;
> 
> 	if (!err)
> 		return 0;
> 
> and then remove a check above.
> 

Argh!!!!  Success handling.  Always do failure handling, never success
handling.

The rest of your comments I agree with, though.

regards,
dan carpenter


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Patch

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 554683912cff..10c982811093 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -118,4 +118,6 @@  source "drivers/staging/vboxvideo/Kconfig"
 
 source "drivers/staging/pi433/Kconfig"
 
+source "drivers/staging/tegra-vde/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 8951c37d8d80..c5ef39767f22 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -49,3 +49,4 @@  obj-$(CONFIG_BCM2835_VCHIQ)	+= vc04_services/
 obj-$(CONFIG_CRYPTO_DEV_CCREE)	+= ccree/
 obj-$(CONFIG_DRM_VBOXVIDEO)	+= vboxvideo/
 obj-$(CONFIG_PI433)		+= pi433/
+obj-$(CONFIG_TEGRA_VDE)		+= tegra-vde/
diff --git a/drivers/staging/tegra-vde/Kconfig b/drivers/staging/tegra-vde/Kconfig
new file mode 100644
index 000000000000..ec3ddddebdaa
--- /dev/null
+++ b/drivers/staging/tegra-vde/Kconfig
@@ -0,0 +1,7 @@ 
+config TEGRA_VDE
+	tristate "NVIDIA Tegra Video Decoder Engine driver"
+	depends on ARCH_TEGRA || COMPILE_TEST
+	select SRAM
+	help
+	    Say Y here to enable support for the NVIDIA Tegra video decoder
+	    driver.
diff --git a/drivers/staging/tegra-vde/Makefile b/drivers/staging/tegra-vde/Makefile
new file mode 100644
index 000000000000..e7c0df1174bf
--- /dev/null
+++ b/drivers/staging/tegra-vde/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_TEGRA_VDE)	+= vde.o
diff --git a/drivers/staging/tegra-vde/TODO b/drivers/staging/tegra-vde/TODO
new file mode 100644
index 000000000000..e98bbc7b3c19
--- /dev/null
+++ b/drivers/staging/tegra-vde/TODO
@@ -0,0 +1,5 @@ 
+TODO:
+	- Figure out how generic V4L2 API could be utilized by this driver,
+	  implement it.
+
+Contact: Dmitry Osipenko <digetx@gmail.com>
diff --git a/drivers/staging/tegra-vde/uapi.h b/drivers/staging/tegra-vde/uapi.h
new file mode 100644
index 000000000000..8502032b5ee2
--- /dev/null
+++ b/drivers/staging/tegra-vde/uapi.h
@@ -0,0 +1,101 @@ 
+/*
+ * Copyright (C) 2016-2017 Dmitry Osipenko <digetx@gmail.com>
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _UAPI_TEGRA_VDE_H_
+#define _UAPI_TEGRA_VDE_H_
+
+#include <linux/types.h>
+#include <asm/ioctl.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#define FLAG_B_FRAME		(1 << 0)
+#define FLAG_REFERENCE		(1 << 1)
+
+struct tegra_vde_h264_frame {
+	__s32 y_fd;
+	__s32 cb_fd;
+	__s32 cr_fd;
+	__s32 aux_fd;
+	__u32 y_offset;
+	__u32 cb_offset;
+	__u32 cr_offset;
+	__u32 aux_offset;
+	__u32 frame_num;
+	__u32 flags;
+
+	__u32 reserved;
+} __attribute__((packed));
+
+struct tegra_vde_h264_decoder_ctx {
+	__s32 bitstream_data_fd;
+	__u32 bitstream_data_offset;
+
+	__u64 dpb_frames_ptr;
+	__u8  dpb_frames_nb;
+	__u8  dpb_ref_frames_with_earlier_poc_nb;
+
+	// SPS
+	__u8  baseline_profile;
+	__u8  level_idc;
+	__u8  log2_max_pic_order_cnt_lsb;
+	__u8  log2_max_frame_num;
+	__u8  pic_order_cnt_type;
+	__u8  direct_8x8_inference_flag;
+	__u8  pic_width_in_mbs;
+	__u8  pic_height_in_mbs;
+
+	// PPS
+	__u8  pic_init_qp;
+	__u8  deblocking_filter_control_present_flag;
+	__u8  constrained_intra_pred_flag;
+	__u8  chroma_qp_index_offset;
+	__u8  pic_order_present_flag;
+
+	// Slice header
+	__u8  num_ref_idx_l0_active_minus1;
+	__u8  num_ref_idx_l1_active_minus1;
+
+	__u32 reserved;
+} __attribute__((packed));
+
+#define VDE_IOCTL_BASE			('v' + 0x20)
+
+#define VDE_IO(nr)			_IO(VDE_IOCTL_BASE, nr)
+#define VDE_IOR(nr, type)		_IOR(VDE_IOCTL_BASE, nr, type)
+#define VDE_IOW(nr, type)		_IOW(VDE_IOCTL_BASE, nr, type)
+#define VDE_IOWR(nr, type)		_IOWR(VDE_IOCTL_BASE, nr, type)
+
+#define TEGRA_VDE_DECODE_H264		0x00
+
+#define TEGRA_VDE_IOCTL_DECODE_H264	\
+	VDE_IOW(TEGRA_VDE_DECODE_H264, struct tegra_vde_h264_decoder_ctx)
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif // _UAPI_TEGRA_VDE_H_
diff --git a/drivers/staging/tegra-vde/vde.c b/drivers/staging/tegra-vde/vde.c
new file mode 100644
index 000000000000..9dbe1d08757e
--- /dev/null
+++ b/drivers/staging/tegra-vde/vde.c
@@ -0,0 +1,1209 @@ 
+/*
+ * NVIDIA Tegra20 Video decoder driver
+ *
+ * Copyright (C) 2016-2017 Dmitry Osipenko <digetx@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-buf.h>
+#include <linux/genalloc.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <soc/tegra/pmc.h>
+
+#include "uapi.h"
+
+#define ICMDQUE_WR		0x00
+#define CMDQUE_CONTROL		0x08
+#define INTR_STATUS		0x18
+#define BSE_INT_ENB		0x40
+#define BSE_CONFIG		0x44
+
+#define BSE_ICMDQUE_EMPTY	BIT(3)
+#define BSE_DMA_BUSY		BIT(23)
+
+#define VDE_WR(__data, __addr)				\
+do {							\
+	dev_dbg(vde->miscdev.parent,			\
+		"%s: %d: 0x%08X => " #__addr ")\n",	\
+		__func__, __LINE__, (u32)(__data));	\
+	writel_relaxed(__data, __addr);			\
+} while (0)
+
+struct video_frame {
+	struct dma_buf_attachment *y_dmabuf_attachment;
+	struct dma_buf_attachment *cb_dmabuf_attachment;
+	struct dma_buf_attachment *cr_dmabuf_attachment;
+	struct dma_buf_attachment *aux_dmabuf_attachment;
+	struct sg_table *y_sgt;
+	struct sg_table *cb_sgt;
+	struct sg_table *cr_sgt;
+	struct sg_table *aux_sgt;
+	dma_addr_t y_addr;
+	dma_addr_t cb_addr;
+	dma_addr_t cr_addr;
+	dma_addr_t aux_addr;
+	u32 frame_num;
+	u32 flags;
+};
+
+struct tegra_vde {
+	void __iomem *sxe;
+	void __iomem *bsev;
+	void __iomem *mbe;
+	void __iomem *ppe;
+	void __iomem *mce;
+	void __iomem *tfe;
+	void __iomem *ppb;
+	void __iomem *vdma;
+	void __iomem *frameid;
+	struct mutex lock;
+	struct miscdevice miscdev;
+	struct reset_control *rst;
+	struct gen_pool *iram_pool;
+	struct completion decode_completion;
+	struct clk *clk;
+	dma_addr_t iram_lists_addr;
+	u32 *iram;
+};
+
+static void tegra_vde_set_bits(struct tegra_vde *vde,
+			       u32 mask, void __iomem *regs)
+{
+	u32 value = readl_relaxed(regs);
+
+	VDE_WR(value | mask, regs);
+}
+
+static int tegra_vde_wait_mbe(struct tegra_vde *vde)
+{
+	u32 tmp;
+
+	return readl_relaxed_poll_timeout(vde->mbe + 0x8C, tmp,
+					  (tmp >= 0x10), 1, 100);
+}
+
+static int tegra_vde_setup_mbe_frame_idx(struct tegra_vde *vde,
+					 unsigned int refs_nb,
+					 bool setup_refs)
+{
+	u32 frame_idx_enb_mask = 0;
+	u32 value;
+	unsigned int frame_idx;
+	unsigned int idx;
+	int err;
+
+	VDE_WR(0xD0000000 | (0 << 23), vde->mbe + 0x80);
+	VDE_WR(0xD0200000 | (0 << 23), vde->mbe + 0x80);
+
+	err = tegra_vde_wait_mbe(vde);
+	if (err)
+		return err;
+
+	if (!setup_refs)
+		return 0;
+
+	for (idx = 0, frame_idx = 1; idx < refs_nb; idx++, frame_idx++) {
+		VDE_WR(0xD0000000 | (frame_idx << 23), vde->mbe + 0x80);
+		VDE_WR(0xD0200000 | (frame_idx << 23), vde->mbe + 0x80);
+
+		frame_idx_enb_mask |= frame_idx << (6 * (idx % 4));
+
+		if (idx % 4 == 3 || idx == refs_nb - 1) {
+			value = 0xC0000000;
+			value |= (idx >> 2) << 24;
+			value |= frame_idx_enb_mask;
+
+			VDE_WR(value, vde->mbe + 0x80);
+
+			err = tegra_vde_wait_mbe(vde);
+			if (err)
+				return err;
+
+			frame_idx_enb_mask = 0;
+		}
+	}
+
+	return 0;
+}
+
+static void tegra_vde_mbe_set_0xa_reg(struct tegra_vde *vde, int reg, u32 val)
+{
+	VDE_WR(0xA0000000 | (reg << 24) | (val & 0xFFFF), vde->mbe + 0x80);
+	VDE_WR(0xA0000000 | ((reg + 1) << 24) | (val >> 16), vde->mbe + 0x80);
+}
+
+static int tegra_vde_wait_bsev(struct tegra_vde *vde, bool wait_dma)
+{
+	struct device *dev = vde->miscdev.parent;
+	u32 value;
+	int err;
+
+	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
+					 !(value & BIT(2)), 1, 100);
+	if (err) {
+		dev_err(dev, "BSEV unknown bit timeout\n");
+		return err;
+	}
+
+	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
+					 (value & BSE_ICMDQUE_EMPTY), 1, 100);
+	if (err) {
+		dev_err(dev, "BSEV ICMDQUE flush timeout\n");
+		return err;
+	}
+
+	if (!wait_dma)
+		return 0;
+
+	err = readl_relaxed_poll_timeout(vde->bsev + INTR_STATUS, value,
+					 !(value & BSE_DMA_BUSY), 1, 100);
+	if (err) {
+		dev_err(dev, "BSEV DMA timeout\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int tegra_vde_push_to_bsev_icmdqueue(struct tegra_vde *vde,
+					    u32 value, bool wait_dma)
+{
+	VDE_WR(value, vde->bsev + ICMDQUE_WR);
+
+	return tegra_vde_wait_bsev(vde, wait_dma);
+}
+
+static void tegra_vde_setup_frameid(struct tegra_vde *vde,
+				    struct video_frame *frame,
+				    unsigned int frameid,
+				    u32 mbs_width, u32 mbs_height)
+{
+	u32 y_addr  = frame ? frame->y_addr  : 0xFCDEAD00;
+	u32 cb_addr = frame ? frame->cb_addr : 0xFCDEAD00;
+	u32 cr_addr = frame ? frame->cr_addr : 0xFCDEAD00;
+	u32 value1 = frame ? ((mbs_width << 16) | mbs_height) : 0;
+	u32 value2 = frame ? ((((mbs_width + 1) >> 1) << 6) | 1) : 0;
+
+	VDE_WR(y_addr  >> 8, vde->frameid + 0x000 + frameid * 4);
+	VDE_WR(cb_addr >> 8, vde->frameid + 0x100 + frameid * 4);
+	VDE_WR(cr_addr >> 8, vde->frameid + 0x180 + frameid * 4);
+	VDE_WR(value1,       vde->frameid + 0x080 + frameid * 4);
+	VDE_WR(value2,       vde->frameid + 0x280 + frameid * 4);
+}
+
+static void tegra_setup_frameidx(struct tegra_vde *vde,
+				 struct video_frame *frames,
+				 unsigned int frames_nb,
+				 u32 mbs_width, u32 mbs_height)
+{
+	unsigned int idx;
+
+	for (idx = 0; idx < frames_nb; idx++)
+		tegra_vde_setup_frameid(vde, &frames[idx], idx,
+					mbs_width, mbs_height);
+	for (; idx < 17; idx++)
+		tegra_vde_setup_frameid(vde, NULL, idx, 0, 0);
+}
+
+static void tegra_vde_setup_iram_entry(u32 *iram_tables,
+				       unsigned int table,
+				       unsigned int row,
+				       u32 value1, u32 value2)
+{
+	pr_debug("IRAM table %u: row %u: 0x%08X 0x%08X\n",
+		 table, row, value1, value2);
+
+	iram_tables[0x20 * table + row * 2] = value1;
+	iram_tables[0x20 * table + row * 2 + 1] = value2;
+}
+
+static void tegra_vde_setup_iram_tables(u32 *iram_tables,
+					struct video_frame *dpb_frames,
+					unsigned int ref_frames_nb,
+					unsigned int with_earlier_poc_nb)
+{
+	struct video_frame *frame;
+	u32 value, aux_addr;
+	int with_later_poc_nb;
+	unsigned int i, k;
+
+	pr_debug("DPB: Frame 0: frame_num = %d\n", dpb_frames[0].frame_num);
+
+	pr_debug("REF L0:\n");
+
+	for (i = 0; i < 16; i++) {
+		if (i < ref_frames_nb) {
+			frame = &dpb_frames[i + 1];
+
+			aux_addr = frame->aux_addr;
+
+			value  = (i + 1) << 26;
+			value |= !(frame->flags & FLAG_B_FRAME) << 25;
+			value |= 1 << 24;
+			value |= frame->frame_num;
+
+			pr_debug("\tFrame %d: frame_num = %d B_frame = %d\n",
+				 i + 1, frame->frame_num,
+				 (frame->flags & FLAG_B_FRAME));
+		} else {
+			aux_addr = 0xFADEAD00;
+			value = 0;
+		}
+
+		tegra_vde_setup_iram_entry(iram_tables, 0, i, value, aux_addr);
+		tegra_vde_setup_iram_entry(iram_tables, 1, i, value, aux_addr);
+		tegra_vde_setup_iram_entry(iram_tables, 2, i, value, aux_addr);
+		tegra_vde_setup_iram_entry(iram_tables, 3, i, value, aux_addr);
+	}
+
+	if (!(dpb_frames[0].flags & FLAG_B_FRAME))
+		return;
+
+	if (with_earlier_poc_nb >= ref_frames_nb)
+		return;
+
+	with_later_poc_nb = ref_frames_nb - with_earlier_poc_nb;
+
+	pr_debug("REF L1: with_later_poc_nb %d with_earlier_poc_nb %d\n",
+		 with_later_poc_nb, with_earlier_poc_nb);
+
+	for (i = 0, k = with_earlier_poc_nb; i < with_later_poc_nb; i++, k++) {
+		frame = &dpb_frames[k + 1];
+
+		aux_addr = frame->aux_addr;
+
+		value  = (k + 1) << 26;
+		value |= !(frame->flags & FLAG_B_FRAME) << 25;
+		value |= 1 << 24;
+		value |= frame->frame_num;
+
+		pr_debug("\tFrame %d: frame_num = %d\n",
+			 k + 1, frame->frame_num);
+
+		tegra_vde_setup_iram_entry(iram_tables, 2, i, value, aux_addr);
+	}
+
+	for (k = 0; i < ref_frames_nb; i++, k++) {
+		frame = &dpb_frames[k + 1];
+
+		aux_addr = frame->aux_addr;
+
+		value  = (k + 1) << 26;
+		value |= !(frame->flags & FLAG_B_FRAME) << 25;
+		value |= 1 << 24;
+		value |= frame->frame_num;
+
+		pr_debug("\tFrame %d: frame_num = %d\n",
+			 k + 1, frame->frame_num);
+
+		tegra_vde_setup_iram_entry(iram_tables, 2, i, value, aux_addr);
+	}
+}
+
+static int tegra_vde_setup_hw_context(struct tegra_vde *vde,
+				      struct tegra_vde_h264_decoder_ctx *ctx,
+				      struct video_frame *dpb_frames,
+				      dma_addr_t bitstream_data_addr,
+				      size_t bitstream_data_size,
+				      unsigned int macroblocks_nb)
+{
+	struct device *dev = vde->miscdev.parent;
+	u32 value;
+	int err;
+
+	tegra_vde_set_bits(vde, 0x000A, vde->sxe + 0xF0);
+	tegra_vde_set_bits(vde, 0x000B, vde->bsev + CMDQUE_CONTROL);
+	tegra_vde_set_bits(vde, 0x8002, vde->mbe + 0x50);
+	tegra_vde_set_bits(vde, 0x000A, vde->mbe + 0xA0);
+	tegra_vde_set_bits(vde, 0x000A, vde->ppe + 0x14);
+	tegra_vde_set_bits(vde, 0x000A, vde->ppe + 0x28);
+	tegra_vde_set_bits(vde, 0x0A00, vde->mce + 0x08);
+	tegra_vde_set_bits(vde, 0x000A, vde->tfe + 0x00);
+	tegra_vde_set_bits(vde, 0x0005, vde->vdma + 0x04);
+
+	VDE_WR(0x00000000, vde->vdma + 0x1C);
+	VDE_WR(0x00000000, vde->vdma + 0x00);
+	VDE_WR(0x00000007, vde->vdma + 0x04);
+	VDE_WR(0x00000007, vde->frameid + 0x200);
+	VDE_WR(0x00000005, vde->tfe + 0x04);
+	VDE_WR(0x00000000, vde->mbe + 0x84);
+	VDE_WR(0x00000010, vde->sxe + 0x08);
+	VDE_WR(0x00000150, vde->sxe + 0x54);
+	VDE_WR(0x0000054C, vde->sxe + 0x58);
+	VDE_WR(0x00000E34, vde->sxe + 0x5C);
+	VDE_WR(0x063C063C, vde->mce + 0x10);
+	VDE_WR(0x0003FC00, vde->bsev + INTR_STATUS);
+	VDE_WR(0x0000150D, vde->bsev + BSE_CONFIG);
+	VDE_WR(0x00000100, vde->bsev + BSE_INT_ENB);
+	VDE_WR(0x00000000, vde->bsev + 0x98);
+	VDE_WR(0x00000060, vde->bsev + 0x9C);
+
+	memset(vde->iram + 128, 0, macroblocks_nb / 2);
+
+	tegra_setup_frameidx(vde, dpb_frames, ctx->dpb_frames_nb,
+			     ctx->pic_width_in_mbs, ctx->pic_height_in_mbs);
+
+	tegra_vde_setup_iram_tables(vde->iram, dpb_frames,
+				    ctx->dpb_frames_nb - 1,
+				    ctx->dpb_ref_frames_with_earlier_poc_nb);
+	wmb();
+
+	VDE_WR(0x00000000, vde->bsev + 0x8C);
+	VDE_WR(bitstream_data_addr + bitstream_data_size,
+	       vde->bsev + 0x54);
+
+	value = ctx->pic_width_in_mbs << 11 | ctx->pic_height_in_mbs << 3;
+
+	VDE_WR(value, vde->bsev + 0x88);
+
+	err = tegra_vde_wait_bsev(vde, false);
+	if (err)
+		return err;
+
+	err = tegra_vde_push_to_bsev_icmdqueue(vde, 0x800003FC, false);
+	if (err)
+		return err;
+
+	value = 0x01500000;
+	value |= ((vde->iram_lists_addr + 512) >> 2) & 0xFFFF;
+
+	err = tegra_vde_push_to_bsev_icmdqueue(vde, value, true);
+	if (err)
+		return err;
+
+	err = tegra_vde_push_to_bsev_icmdqueue(vde, 0x840F054C, false);
+	if (err)
+		return err;
+
+	err = tegra_vde_push_to_bsev_icmdqueue(vde, 0x80000080, false);
+	if (err)
+		return err;
+
+	value = 0x0E340000 | ((vde->iram_lists_addr >> 2) & 0xFFFF);
+
+	err = tegra_vde_push_to_bsev_icmdqueue(vde, value, true);
+	if (err)
+		return err;
+
+	value = 0x00800005;
+	value |= ctx->pic_width_in_mbs << 11;
+	value |= ctx->pic_height_in_mbs << 3;
+
+	VDE_WR(value, vde->sxe + 0x10);
+
+	value = !ctx->baseline_profile << 17;
+	value |= ctx->level_idc << 13;
+	value |= ctx->log2_max_pic_order_cnt_lsb << 7;
+	value |= ctx->pic_order_cnt_type << 5;
+	value |= ctx->log2_max_frame_num;
+
+	VDE_WR(value, vde->sxe + 0x40);
+
+	value = ctx->pic_init_qp << 25;
+	value |= !!(ctx->deblocking_filter_control_present_flag) << 2;
+	value |= !!ctx->pic_order_present_flag;
+
+	VDE_WR(value, vde->sxe + 0x44);
+
+	value = ctx->chroma_qp_index_offset;
+	value |= ctx->num_ref_idx_l0_active_minus1 << 5;
+	value |= ctx->num_ref_idx_l1_active_minus1 << 10;
+	value |= !!ctx->constrained_intra_pred_flag << 15;
+
+	VDE_WR(value, vde->sxe + 0x48);
+
+	value = 0x0C000000;
+	value |= !!(dpb_frames[0].flags & FLAG_B_FRAME) << 24;
+
+	VDE_WR(value, vde->sxe + 0x4C);
+
+	value = 0x03800000;
+	value |= min_t(size_t, bitstream_data_size, SZ_1M);
+
+	VDE_WR(value, vde->sxe + 0x68);
+
+	VDE_WR(bitstream_data_addr, vde->sxe + 0x6C);
+
+	value = 0x10000005;
+	value |= ctx->pic_width_in_mbs << 11;
+	value |= ctx->pic_height_in_mbs << 3;
+
+	VDE_WR(value, vde->mbe + 0x80);
+
+	value = 0x26800000;
+	value |= ctx->level_idc << 4;
+	value |= !ctx->baseline_profile << 1;
+	value |= !!ctx->direct_8x8_inference_flag;
+
+	VDE_WR(value, vde->mbe + 0x80);
+
+	VDE_WR(0xF4000001, vde->mbe + 0x80);
+	VDE_WR(0x20000000, vde->mbe + 0x80);
+	VDE_WR(0xF4000101, vde->mbe + 0x80);
+
+	value = 0x20000000;
+	value |= ctx->chroma_qp_index_offset << 8;
+
+	VDE_WR(value, vde->mbe + 0x80);
+
+	err = tegra_vde_setup_mbe_frame_idx(vde,
+					    ctx->dpb_frames_nb - 1,
+					    ctx->pic_order_cnt_type == 0);
+	if (err) {
+		dev_err(dev, "MBE frames setup failed\n");
+		return err;
+	}
+
+	tegra_vde_mbe_set_0xa_reg(vde, 0, 0x000009FC);
+	tegra_vde_mbe_set_0xa_reg(vde, 2, 0xF1DEAD00);
+	tegra_vde_mbe_set_0xa_reg(vde, 4, 0xF2DEAD00);
+	tegra_vde_mbe_set_0xa_reg(vde, 6, 0xF3DEAD00);
+	tegra_vde_mbe_set_0xa_reg(vde, 8, dpb_frames[0].aux_addr);
+
+	value = 0xFC000000;
+	value |= !!(dpb_frames[0].flags & FLAG_B_FRAME) << 2;
+
+	if (!ctx->baseline_profile)
+		value |= !!(dpb_frames[0].flags & FLAG_REFERENCE) << 1;
+
+	VDE_WR(value, vde->mbe + 0x80);
+
+	err = tegra_vde_wait_mbe(vde);
+	if (err) {
+		dev_err(dev, "MBE programming failed\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static void tegra_vde_decode_frame(struct tegra_vde *vde,
+				   unsigned int macroblocks_nb)
+{
+	reinit_completion(&vde->decode_completion);
+
+	VDE_WR(0x00000001, vde->bsev + 0x8C);
+	VDE_WR(0x20000000 | (macroblocks_nb - 1), vde->sxe + 0x00);
+}
+
+static void tegra_vde_detach_and_put_dmabuf(struct dma_buf_attachment *a,
+					    struct sg_table *sgt,
+					    enum dma_data_direction dma_dir)
+{
+	struct dma_buf *dmabuf = a->dmabuf;
+
+	dma_buf_unmap_attachment(a, sgt, dma_dir);
+	dma_buf_detach(dmabuf, a);
+	dma_buf_put(dmabuf);
+}
+
+static int tegra_vde_attach_dmabuf(struct device *dev,
+				   int fd,
+				   unsigned long offset,
+				   unsigned int min_size,
+				   struct dma_buf_attachment **a,
+				   dma_addr_t *addr,
+				   struct sg_table **s,
+				   size_t *size,
+				   enum dma_data_direction dma_dir)
+{
+	struct dma_buf_attachment *attachment;
+	struct dma_buf *dmabuf;
+	struct sg_table *sgt;
+	int err;
+
+	dmabuf = dma_buf_get(fd);
+	if (IS_ERR(dmabuf)) {
+		dev_err(dev, "Invalid dmabuf FD\n");
+		return PTR_ERR(dmabuf);
+	}
+
+	if ((u64)offset + min_size > dmabuf->size) {
+		dev_err(dev, "Too small dmabuf size %zu @0x%lX, "
+			     "should be at least %d\n",
+			dmabuf->size, offset, min_size);
+		return -EINVAL;
+	}
+
+	attachment = dma_buf_attach(dmabuf, dev);
+	if (IS_ERR(attachment)) {
+		dev_err(dev, "Failed to attach dmabuf\n");
+		err = PTR_ERR(attachment);
+		goto err_put;
+	}
+
+	sgt = dma_buf_map_attachment(attachment, dma_dir);
+	if (IS_ERR(sgt)) {
+		dev_err(dev, "Failed to get dmabufs sg_table\n");
+		err = PTR_ERR(sgt);
+		goto err_detach;
+	}
+
+	if (sgt->nents != 1) {
+		dev_err(dev, "Sparse DMA region is unsupported\n");
+		err = -EINVAL;
+		goto err_unmap;
+	}
+
+	*addr = sg_dma_address(sgt->sgl) + offset;
+	*a = attachment;
+	*s = sgt;
+
+	if (size)
+		*size = dmabuf->size - offset;
+
+	return 0;
+
+err_unmap:
+	dma_buf_unmap_attachment(attachment, sgt, dma_dir);
+err_detach:
+	dma_buf_detach(dmabuf, attachment);
+err_put:
+	dma_buf_put(dmabuf);
+
+	return err;
+}
+
+static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
+					struct video_frame *frame,
+					struct tegra_vde_h264_frame *source,
+					enum dma_data_direction dma_dir,
+					bool baseline_profile,
+					size_t csize)
+{
+	int err;
+
+	err = tegra_vde_attach_dmabuf(dev, source->y_fd,
+				      source->y_offset, csize * 4,
+				      &frame->y_dmabuf_attachment,
+				      &frame->y_addr,
+				      &frame->y_sgt,
+				      NULL, dma_dir);
+	if (err)
+		return err;
+
+	err = tegra_vde_attach_dmabuf(dev, source->cb_fd,
+				      source->cb_offset, csize,
+				      &frame->cb_dmabuf_attachment,
+				      &frame->cb_addr,
+				      &frame->cb_sgt,
+				      NULL, dma_dir);
+	if (err)
+		goto err_release_y;
+
+	err = tegra_vde_attach_dmabuf(dev, source->cr_fd,
+				      source->cr_offset, csize,
+				      &frame->cr_dmabuf_attachment,
+				      &frame->cr_addr,
+				      &frame->cr_sgt,
+				      NULL, dma_dir);
+	if (err)
+		goto err_release_cb;
+
+	if (baseline_profile) {
+		frame->aux_addr = 0xF4DEAD00;
+	} else {
+		err = tegra_vde_attach_dmabuf(dev, source->aux_fd,
+					      source->aux_offset, csize,
+					      &frame->aux_dmabuf_attachment,
+					      &frame->aux_addr,
+					      &frame->aux_sgt,
+					      NULL, dma_dir);
+		if (err)
+			goto err_release_cr;
+	}
+
+	return 0;
+
+err_release_cr:
+	tegra_vde_detach_and_put_dmabuf(frame->cr_dmabuf_attachment,
+					frame->cr_sgt, dma_dir);
+err_release_cb:
+	tegra_vde_detach_and_put_dmabuf(frame->cb_dmabuf_attachment,
+					frame->cb_sgt, dma_dir);
+err_release_y:
+	tegra_vde_detach_and_put_dmabuf(frame->y_dmabuf_attachment,
+					frame->y_sgt, dma_dir);
+
+	return err;
+}
+
+static void tegra_vde_deattach_frame_dmabufs(struct video_frame *frame,
+					     enum dma_data_direction dma_dir,
+					     bool baseline_profile)
+{
+	if (!baseline_profile)
+		tegra_vde_detach_and_put_dmabuf(frame->aux_dmabuf_attachment,
+						frame->aux_sgt, dma_dir);
+
+	tegra_vde_detach_and_put_dmabuf(frame->cr_dmabuf_attachment,
+					frame->cr_sgt, dma_dir);
+
+	tegra_vde_detach_and_put_dmabuf(frame->cb_dmabuf_attachment,
+					frame->cb_sgt, dma_dir);
+
+	tegra_vde_detach_and_put_dmabuf(frame->y_dmabuf_attachment,
+					frame->y_sgt, dma_dir);
+}
+
+static int tegra_vde_validate_frame(struct device *dev,
+				    struct tegra_vde_h264_frame *frame)
+{
+	if (frame->frame_num > 0x7FFFFF) {
+		dev_err(dev, "Bad frame_num %u\n", frame->frame_num);
+		return -EINVAL;
+	}
+
+	if (frame->y_offset & 0xFF) {
+		dev_err(dev, "Bad y_offset 0x%X\n", frame->y_offset);
+		return -EINVAL;
+	}
+
+	if (frame->cb_offset & 0xFF) {
+		dev_err(dev, "Bad cb_offset 0x%X\n", frame->cb_offset);
+		return -EINVAL;
+	}
+
+	if (frame->cr_offset & 0xFF) {
+		dev_err(dev, "Bad cr_offset 0x%X\n", frame->cr_offset);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int tegra_vde_validate_h264_ctx(struct device *dev,
+				       struct tegra_vde_h264_decoder_ctx *ctx)
+{
+	if (ctx->dpb_frames_nb == 0 || ctx->dpb_frames_nb > 17) {
+		dev_err(dev, "Bad DPB size %u\n", ctx->dpb_frames_nb);
+		return -EINVAL;
+	}
+
+	if (ctx->level_idc > 15) {
+		dev_err(dev, "Bad level value %u\n", ctx->level_idc);
+		return -EINVAL;
+	}
+
+	if (ctx->pic_init_qp > 52) {
+		dev_err(dev, "Bad pic_init_qp value %u\n", ctx->pic_init_qp);
+		return -EINVAL;
+	}
+
+	if (ctx->log2_max_pic_order_cnt_lsb > 16) {
+		dev_err(dev, "Bad log2_max_pic_order_cnt_lsb value %u\n",
+			ctx->log2_max_pic_order_cnt_lsb);
+		return -EINVAL;
+	}
+
+	if (ctx->log2_max_frame_num > 16) {
+		dev_err(dev, "Bad log2_max_frame_num value %u\n",
+			ctx->log2_max_frame_num);
+		return -EINVAL;
+	}
+
+	if (ctx->chroma_qp_index_offset > 31) {
+		dev_err(dev, "Bad chroma_qp_index_offset value %u\n",
+			ctx->chroma_qp_index_offset);
+		return -EINVAL;
+	}
+
+	if (ctx->pic_order_cnt_type > 2) {
+		dev_err(dev, "Bad pic_order_cnt_type value %u\n",
+			ctx->pic_order_cnt_type);
+		return -EINVAL;
+	}
+
+	if (ctx->num_ref_idx_l0_active_minus1 > 15) {
+		dev_err(dev, "Bad num_ref_idx_l0_active_minus1 value %u\n",
+			ctx->num_ref_idx_l0_active_minus1);
+		return -EINVAL;
+	}
+
+	if (ctx->num_ref_idx_l1_active_minus1 > 15) {
+		dev_err(dev, "Bad num_ref_idx_l1_active_minus1 value %u\n",
+			ctx->num_ref_idx_l1_active_minus1);
+		return -EINVAL;
+	}
+
+	if (!ctx->pic_width_in_mbs || ctx->pic_width_in_mbs > 127) {
+		dev_err(dev, "Bad pic_width_in_mbs value %u\n",
+			ctx->pic_width_in_mbs);
+		return -EINVAL;
+	}
+
+	if (!ctx->pic_height_in_mbs || ctx->pic_height_in_mbs > 127) {
+		dev_err(dev, "Bad pic_height_in_mbs value %u\n",
+			ctx->pic_height_in_mbs);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
+				       unsigned long vaddr)
+{
+	struct device *dev = vde->miscdev.parent;
+	struct tegra_vde_h264_decoder_ctx ctx;
+	struct tegra_vde_h264_frame __user *frames_user;
+	struct tegra_vde_h264_frame *frames;
+	struct video_frame *dpb_frames;
+	struct dma_buf_attachment *bitstream_data_dmabuf_attachment;
+	struct sg_table *bitstream_sgt;
+	enum dma_data_direction dma_dir;
+	dma_addr_t bitstream_data_addr;
+	dma_addr_t bsev_ptr;
+	size_t bitstream_data_size;
+	unsigned int macroblocks_nb;
+	unsigned int read_bytes;
+	unsigned int i = 0;
+	bool timeout;
+	int ret;
+
+	if (copy_from_user(&ctx, (void __user *)vaddr, sizeof(ctx)))
+		return -EFAULT;
+
+	ret = tegra_vde_validate_h264_ctx(dev, &ctx);
+	if (ret)
+		return -EINVAL;
+
+	ret = tegra_vde_attach_dmabuf(dev, ctx.bitstream_data_fd,
+				      ctx.bitstream_data_offset, 0,
+				      &bitstream_data_dmabuf_attachment,
+				      &bitstream_data_addr,
+				      &bitstream_sgt,
+				      &bitstream_data_size,
+				      DMA_TO_DEVICE);
+	if (ret)
+		return ret;
+
+	dpb_frames = kcalloc(ctx.dpb_frames_nb, sizeof(*dpb_frames),
+			     GFP_KERNEL);
+	if (!dpb_frames) {
+		ret = -ENOMEM;
+		goto err_release_bitstream_dmabuf;
+	}
+
+	macroblocks_nb = ctx.pic_width_in_mbs * ctx.pic_height_in_mbs;
+	frames_user = u64_to_user_ptr(ctx.dpb_frames_ptr);
+
+	frames = kmalloc_array(ctx.dpb_frames_nb, sizeof(*frames), GFP_KERNEL);
+	if (!frames) {
+		ret = -ENOMEM;
+		goto err_release_dpb_frames;
+	}
+
+	if (copy_from_user(frames, frames_user,
+			   ctx.dpb_frames_nb * sizeof(*frames))) {
+		ret = -EFAULT;
+		goto free_frames;
+	}
+
+	for (i = 0; i < ctx.dpb_frames_nb; i++) {
+		ret = tegra_vde_validate_frame(dev, &frames[i]);
+		if (ret)
+			goto free_frames;
+
+		dpb_frames[i].flags = frames[i].flags;
+		dpb_frames[i].frame_num = frames[i].frame_num;
+
+		dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+		ret = tegra_vde_attach_dmabufs_to_frame(dev, &dpb_frames[i],
+							&frames[i], dma_dir,
+							ctx.baseline_profile,
+							macroblocks_nb * 64);
+		if (ret)
+			goto free_frames;
+	}
+
+free_frames:
+	kfree(frames);
+
+	if (ret)
+		goto err_release_dpb_frames;
+
+	ret = mutex_lock_interruptible(&vde->lock);
+	if (ret)
+		goto err_release_dpb_frames;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		goto err_unlock;
+
+	/*
+	 * We rely on the VDE registers reset value, otherwise VDE
+	 * causes bus lockup.
+	 */
+	ret = reset_control_reset(vde->rst);
+	if (ret) {
+		dev_err(dev, "Failed to reset HW: %d\n", ret);
+		goto err_put_runtime_pm;
+	}
+
+	ret = tegra_vde_setup_hw_context(vde, &ctx, dpb_frames,
+					 bitstream_data_addr,
+					 bitstream_data_size,
+					 macroblocks_nb);
+	if (ret)
+		goto err_put_runtime_pm;
+
+	tegra_vde_decode_frame(vde, macroblocks_nb);
+
+	timeout = !wait_for_completion_killable_timeout(&vde->decode_completion,
+							msecs_to_jiffies(1000));
+	if (timeout) {
+		bsev_ptr = readl_relaxed(vde->bsev + 0x10);
+		macroblocks_nb = readl_relaxed(vde->sxe + 0xC8) & 0x1FFF;
+		read_bytes = bsev_ptr ? bsev_ptr - bitstream_data_addr : 0;
+
+		dev_err(dev, "Decoding failed, "
+				"read 0x%X bytes : %u macroblocks parsed\n",
+			read_bytes, macroblocks_nb);
+
+		ret = -EIO;
+	}
+
+	reset_control_assert(vde->rst);
+
+err_put_runtime_pm:
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+err_unlock:
+	mutex_unlock(&vde->lock);
+
+err_release_dpb_frames:
+	while (i--) {
+		dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+		tegra_vde_deattach_frame_dmabufs(&dpb_frames[i], dma_dir,
+						 ctx.baseline_profile);
+	}
+
+	kfree(dpb_frames);
+
+err_release_bitstream_dmabuf:
+	tegra_vde_detach_and_put_dmabuf(bitstream_data_dmabuf_attachment,
+					bitstream_sgt, DMA_TO_DEVICE);
+
+	return ret;
+}
+
+static long tegra_vde_unlocked_ioctl(struct file *filp,
+				     unsigned int cmd, unsigned long arg)
+{
+	struct miscdevice *miscdev = filp->private_data;
+	struct tegra_vde *vde = container_of(miscdev, struct tegra_vde,
+					     miscdev);
+
+	switch (cmd) {
+	case TEGRA_VDE_IOCTL_DECODE_H264:
+		return tegra_vde_ioctl_decode_h264(vde, arg);
+	}
+
+	dev_err(miscdev->parent, "Invalid IOCTL command %u\n", cmd);
+
+	return -ENOTTY;
+}
+
+static const struct file_operations tegra_vde_fops = {
+	.owner		= THIS_MODULE,
+	.unlocked_ioctl	= tegra_vde_unlocked_ioctl,
+};
+
+static irqreturn_t tegra_vde_isr(int irq, void *data)
+{
+	struct tegra_vde *vde = data;
+
+	tegra_vde_set_bits(vde, 0, vde->frameid + 0x208);
+	complete(&vde->decode_completion);
+
+	return IRQ_HANDLED;
+}
+
+static int tegra_vde_runtime_suspend(struct device *dev)
+{
+	struct tegra_vde *vde = dev_get_drvdata(dev);
+	int err;
+
+	err = tegra_powergate_power_off(TEGRA_POWERGATE_VDEC);
+	if (err) {
+		dev_err(dev, "Failed to power down HW: %d\n", err);
+		return err;
+	}
+
+	clk_disable_unprepare(vde->clk);
+
+	return 0;
+}
+
+static int tegra_vde_runtime_resume(struct device *dev)
+{
+	struct tegra_vde *vde = dev_get_drvdata(dev);
+	int err;
+
+	err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_VDEC,
+						vde->clk, vde->rst);
+	if (err) {
+		dev_err(dev, "Failed to power up HW : %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int tegra_vde_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *regs;
+	struct tegra_vde *vde;
+	int irq, err;
+
+	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
+	if (!vde)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, vde);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sxe");
+	if (!regs)
+		return -ENODEV;
+
+	vde->sxe = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->sxe))
+		return PTR_ERR(vde->sxe);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "bsev");
+	if (!regs)
+		return -ENODEV;
+
+	vde->bsev = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->bsev))
+		return PTR_ERR(vde->bsev);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mbe");
+	if (!regs)
+		return -ENODEV;
+
+	vde->mbe = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->mbe))
+		return PTR_ERR(vde->mbe);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ppe");
+	if (!regs)
+		return -ENODEV;
+
+	vde->ppe = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->ppe))
+		return PTR_ERR(vde->ppe);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mce");
+	if (!regs)
+		return -ENODEV;
+
+	vde->mce = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->mce))
+		return PTR_ERR(vde->mce);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "tfe");
+	if (!regs)
+		return -ENODEV;
+
+	vde->tfe = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->tfe))
+		return PTR_ERR(vde->tfe);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ppb");
+	if (!regs)
+		return -ENODEV;
+
+	vde->ppb = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->ppb))
+		return PTR_ERR(vde->ppb);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vdma");
+	if (!regs)
+		return -ENODEV;
+
+	vde->vdma = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->vdma))
+		return PTR_ERR(vde->vdma);
+
+	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "frameid");
+	if (!regs)
+		return -ENODEV;
+
+	vde->frameid = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(vde->frameid))
+		return PTR_ERR(vde->frameid);
+
+	vde->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(vde->clk)) {
+		err = PTR_ERR(vde->clk);
+		dev_err(dev, "Could not get VDE clk %d\n", err);
+		return err;
+	}
+
+	vde->rst = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(vde->rst)) {
+		err = PTR_ERR(vde->rst);
+		dev_err(dev, "Could not get VDE reset %d\n", err);
+		return err;
+	}
+
+	irq = platform_get_irq_byname(pdev, "sync-token");
+	if (irq < 0)
+		return irq;
+
+	err = devm_request_irq(dev, irq, tegra_vde_isr, 0,
+			       dev_name(dev), vde);
+	if (err) {
+		dev_err(dev, "Could not request IRQ %d\n", err);
+		return err;
+	}
+
+	vde->iram_pool = of_gen_pool_get(dev->of_node, "iram", 0);
+	if (!vde->iram_pool) {
+		dev_err(dev, "Could not get IRAM pool\n");
+		return -EPROBE_DEFER;
+	}
+
+	vde->iram = gen_pool_dma_alloc(vde->iram_pool, 0x3FC00,
+				       &vde->iram_lists_addr);
+	if (!vde->iram) {
+		dev_err(dev, "Could not reserve IRAM\n");
+		return -ENOMEM;
+	}
+
+	mutex_init(&vde->lock);
+	init_completion(&vde->decode_completion);
+
+	vde->miscdev.minor = MISC_DYNAMIC_MINOR;
+	vde->miscdev.name = "tegra_vde";
+	vde->miscdev.fops = &tegra_vde_fops;
+	vde->miscdev.parent = dev;
+
+	err = misc_register(&vde->miscdev);
+	if (err) {
+		dev_err(dev, "Failed to register misc device: %d\n", err);
+		goto err_gen_free;
+	}
+
+	pm_runtime_enable(dev);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 300);
+
+	if (!pm_runtime_enabled(dev)) {
+		err = tegra_vde_runtime_resume(dev);
+		if (err)
+			goto err_misc_unreg;
+	}
+
+	return 0;
+
+err_misc_unreg:
+	misc_deregister(&vde->miscdev);
+
+err_gen_free:
+	gen_pool_free(vde->iram_pool,
+		      (unsigned long)vde->iram, 0x3FC00);
+
+	return err;
+}
+
+static int tegra_vde_remove(struct platform_device *pdev)
+{
+	struct tegra_vde *vde = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+	int err;
+
+	if (!pm_runtime_enabled(dev)) {
+		err = tegra_vde_runtime_suspend(dev);
+		if (err)
+			return err;
+	}
+
+	pm_runtime_dont_use_autosuspend(dev);
+	pm_runtime_disable(dev);
+
+	misc_deregister(&vde->miscdev);
+
+	gen_pool_free(vde->iram_pool,
+		      (unsigned long)vde->iram, 0x3FC00);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_vde_pm_suspend(struct device *dev)
+{
+	struct tegra_vde *vde = dev_get_drvdata(dev);
+	int err;
+
+	mutex_lock(&vde->lock);
+
+	err = pm_runtime_force_suspend(dev);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int tegra_vde_pm_resume(struct device *dev)
+{
+	struct tegra_vde *vde = dev_get_drvdata(dev);
+	int err;
+
+	err = pm_runtime_force_resume(dev);
+	if (err < 0)
+		return err;
+
+	mutex_unlock(&vde->lock);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops tegra_vde_pm_ops = {
+	SET_RUNTIME_PM_OPS(tegra_vde_runtime_suspend,
+			   tegra_vde_runtime_resume,
+			   NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(tegra_vde_pm_suspend,
+				tegra_vde_pm_resume)
+};
+
+static const struct of_device_id tegra_vde_of_match[] = {
+	{ .compatible = "nvidia,tegra20-vde", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_vde_of_match);
+
+static struct platform_driver tegra_vde_driver = {
+	.probe		= tegra_vde_probe,
+	.remove		= tegra_vde_remove,
+	.driver		= {
+		.name		= "tegra-vde",
+		.of_match_table = tegra_vde_of_match,
+		.pm		= &tegra_vde_pm_ops,
+	},
+};
+module_platform_driver(tegra_vde_driver);
+
+MODULE_DESCRIPTION("NVIDIA Tegra20 Video Decoder driver");
+MODULE_AUTHOR("Dmitry Osipenko");
+MODULE_LICENSE("GPL");