diff mbox series

[v13,2/5] media: renesas: vsp1: Add support to deassert/assert reset line

Message ID 20220825132144.2619239-3-biju.das.jz@bp.renesas.com
State Superseded
Headers show
Series Add support for RZ/G2L VSPD | expand

Commit Message

Biju Das Aug. 25, 2022, 1:21 p.m. UTC 
As the resets DT property is mandatory, and is present in all .dtsi
in mainline, add support to perform deassert/assert using reference
counted reset handle.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v12->v13:
 * Removed unused iopoll.h header file.
 * Added Rb tag from Geert.
v11->v12:
 * Replaced read_poll_timeout_atomic-> udelay(1) as testing on RZ/G1N
   shows this delay is sufficient to avoid lock-up.
 * Removed Rb tags.
v10->v11:
 * To avoid lock-up on R-Car Gen2, added poll for reset status after deassert.
v9->v10:
 * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
v8->v9:
 * No change
v7->v8:
 * No Change
v6->v7:
 * No change
v5->v6:
 * Rebased to media_staging and updated commit header
 * Added Rb tag from Laurent
 * Added forward declaration for struct reset_control
 * Updated vsp1_device_get() with changes suggested by Laurent
 * Updated error message for reset_control_get form ctrl->control.
v4->v5:
 * Added Rb tag from Geert
v3->v4:
 * Restored error check for pm_runtime_resume_and_get and calls
   assert() in case of failure.
v2->v3:
 * Added Rb tag from Philipp
 * If reset_control_deassert() failed, return ret directly. 
v1->v2:
 * Used reference counted reset handle to perform deassert/assert
RFC->v1:
 * Added reset support as separate patch
 * Moved rstc just after the bus_master field in struct vsp1_device
RFC:
 * https://patchwork.kernel.org/project/linux-renesas-soc/patch/20220112174612.10773-21-biju.das.jz@bp.renesas.com/
---
 drivers/media/platform/renesas/vsp1/vsp1.h    |  2 ++
 .../media/platform/renesas/vsp1/vsp1_drv.c    | 28 +++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

Comments

Laurent Pinchart Aug. 27, 2022, 12:45 a.m. UTC | #1 
Hi Biju,

Thank you for the patch.

On Thu, Aug 25, 2022 at 02:21:41PM +0100, Biju Das wrote:
> As the resets DT property is mandatory, and is present in all .dtsi
> in mainline, add support to perform deassert/assert using reference
> counted reset handle.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v12->v13:
>  * Removed unused iopoll.h header file.
>  * Added Rb tag from Geert.
> v11->v12:
>  * Replaced read_poll_timeout_atomic-> udelay(1) as testing on RZ/G1N
>    shows this delay is sufficient to avoid lock-up.
>  * Removed Rb tags.
> v10->v11:
>  * To avoid lock-up on R-Car Gen2, added poll for reset status after deassert.
> v9->v10:
>  * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
> v8->v9:
>  * No change
> v7->v8:
>  * No Change
> v6->v7:
>  * No change
> v5->v6:
>  * Rebased to media_staging and updated commit header
>  * Added Rb tag from Laurent
>  * Added forward declaration for struct reset_control
>  * Updated vsp1_device_get() with changes suggested by Laurent
>  * Updated error message for reset_control_get form ctrl->control.
> v4->v5:
>  * Added Rb tag from Geert
> v3->v4:
>  * Restored error check for pm_runtime_resume_and_get and calls
>    assert() in case of failure.
> v2->v3:
>  * Added Rb tag from Philipp
>  * If reset_control_deassert() failed, return ret directly. 
> v1->v2:
>  * Used reference counted reset handle to perform deassert/assert
> RFC->v1:
>  * Added reset support as separate patch
>  * Moved rstc just after the bus_master field in struct vsp1_device
> RFC:
>  * https://patchwork.kernel.org/project/linux-renesas-soc/patch/20220112174612.10773-21-biju.das.jz@bp.renesas.com/
> ---
>  drivers/media/platform/renesas/vsp1/vsp1.h    |  2 ++
>  .../media/platform/renesas/vsp1/vsp1_drv.c    | 28 +++++++++++++++++--
>  2 files changed, 28 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/vsp1/vsp1.h b/drivers/media/platform/renesas/vsp1/vsp1.h
> index 37cf33c7e6ca..baf898d577ec 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1.h
> +++ b/drivers/media/platform/renesas/vsp1/vsp1.h
> @@ -22,6 +22,7 @@
>  struct clk;
>  struct device;
>  struct rcar_fcp_device;
> +struct reset_control;
>  
>  struct vsp1_drm;
>  struct vsp1_entity;
> @@ -79,6 +80,7 @@ struct vsp1_device {
>  	void __iomem *mmio;
>  	struct rcar_fcp_device *fcp;
>  	struct device *bus_master;
> +	struct reset_control *rstc;
>  
>  	struct vsp1_brx *brs;
>  	struct vsp1_brx *bru;
> diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drv.c b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> index 1f73c48eb738..975e6851735e 100644
> --- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> @@ -16,6 +16,7 @@
>  #include <linux/of_device.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/reset.h>
>  #include <linux/videodev2.h>
>  
>  #include <media/rcar-fcp.h>
> @@ -622,6 +623,7 @@ static int __maybe_unused vsp1_pm_runtime_suspend(struct device *dev)
>  	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
>  
>  	rcar_fcp_disable(vsp1->fcp);
> +	reset_control_assert(vsp1->rstc);
>  
>  	return 0;
>  }
> @@ -631,13 +633,30 @@ static int __maybe_unused vsp1_pm_runtime_resume(struct device *dev)
>  	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
>  	int ret;
>  
> +	ret = reset_control_deassert(vsp1->rstc);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * On R-Car Gen2, vsp1 register access after deassert can cause
> +	 * lock-up. It is a special case and needs some delay to avoid
> +	 * this lock-up.

You can reflow this to 80 columns:

	 * On R-Car Gen2, vsp1 register access after deassert can cause lock-up.
	 * It is a special case and needs some delay to avoid this lock-up.

> +	 */
> +	udelay(1);

Is it worth conditioning this on the VSP version to only add the delay
on Gen2 ?

With these two small issues addressed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +
>  	if (vsp1->info) {
>  		ret = vsp1_device_init(vsp1);
>  		if (ret < 0)
> -			return ret;
> +			goto done;
>  	}
>  
> -	return rcar_fcp_enable(vsp1->fcp);
> +	ret = rcar_fcp_enable(vsp1->fcp);
> +
> +done:
> +	if (ret < 0)
> +		reset_control_assert(vsp1->rstc);
> +
> +	return ret;
>  }
>  
>  static const struct dev_pm_ops vsp1_pm_ops = {
> @@ -825,6 +844,11 @@ static int vsp1_probe(struct platform_device *pdev)
>  	if (irq < 0)
>  		return irq;
>  
> +	vsp1->rstc = devm_reset_control_get_shared(&pdev->dev, NULL);
> +	if (IS_ERR(vsp1->rstc))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(vsp1->rstc),
> +				     "failed to get reset control\n");
> +
>  	/* FCP (optional). */
>  	fcp_node = of_parse_phandle(pdev->dev.of_node, "renesas,fcp", 0);
>  	if (fcp_node) {
Biju Das Aug. 27, 2022, 4:07 p.m. UTC | #2 
Hi Laurent,

Thanks for the feedback.

> Subject: Re: [PATCH v13 2/5] media: renesas: vsp1: Add support to
> deassert/assert reset line
> 
> Hi Biju,
> 
> Thank you for the patch.
> 
> On Thu, Aug 25, 2022 at 02:21:41PM +0100, Biju Das wrote:
> > As the resets DT property is mandatory, and is present in all .dtsi in
> > mainline, add support to perform deassert/assert using reference
> > counted reset handle.
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > ---
> > v12->v13:
> >  * Removed unused iopoll.h header file.
> >  * Added Rb tag from Geert.
> > v11->v12:
> >  * Replaced read_poll_timeout_atomic-> udelay(1) as testing on RZ/G1N
> >    shows this delay is sufficient to avoid lock-up.
> >  * Removed Rb tags.
> > v10->v11:
> >  * To avoid lock-up on R-Car Gen2, added poll for reset status after
> deassert.
> > v9->v10:
> >  * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
> > v8->v9:
> >  * No change
> > v7->v8:
> >  * No Change
> > v6->v7:
> >  * No change
> > v5->v6:
> >  * Rebased to media_staging and updated commit header
> >  * Added Rb tag from Laurent
> >  * Added forward declaration for struct reset_control
> >  * Updated vsp1_device_get() with changes suggested by Laurent
> >  * Updated error message for reset_control_get form ctrl->control.
> > v4->v5:
> >  * Added Rb tag from Geert
> > v3->v4:
> >  * Restored error check for pm_runtime_resume_and_get and calls
> >    assert() in case of failure.
> > v2->v3:
> >  * Added Rb tag from Philipp
> >  * If reset_control_deassert() failed, return ret directly.
> > v1->v2:
> >  * Used reference counted reset handle to perform deassert/assert
> > RFC->v1:
> >  * Added reset support as separate patch
> >  * Moved rstc just after the bus_master field in struct vsp1_device
> > RFC:
> >  *
> > ---
> >  drivers/media/platform/renesas/vsp1/vsp1.h    |  2 ++
> >  .../media/platform/renesas/vsp1/vsp1_drv.c    | 28 +++++++++++++++++-
> -
> >  2 files changed, 28 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/platform/renesas/vsp1/vsp1.h
> > b/drivers/media/platform/renesas/vsp1/vsp1.h
> > index 37cf33c7e6ca..baf898d577ec 100644
> > --- a/drivers/media/platform/renesas/vsp1/vsp1.h
> > +++ b/drivers/media/platform/renesas/vsp1/vsp1.h
> > @@ -22,6 +22,7 @@
> >  struct clk;
> >  struct device;
> >  struct rcar_fcp_device;
> > +struct reset_control;
> >
> >  struct vsp1_drm;
> >  struct vsp1_entity;
> > @@ -79,6 +80,7 @@ struct vsp1_device {
> >  	void __iomem *mmio;
> >  	struct rcar_fcp_device *fcp;
> >  	struct device *bus_master;
> > +	struct reset_control *rstc;
> >
> >  	struct vsp1_brx *brs;
> >  	struct vsp1_brx *bru;
> > diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > index 1f73c48eb738..975e6851735e 100644
> > --- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > +++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > @@ -16,6 +16,7 @@
> >  #include <linux/of_device.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/pm_runtime.h>
> > +#include <linux/reset.h>
> >  #include <linux/videodev2.h>
> >
> >  #include <media/rcar-fcp.h>
> > @@ -622,6 +623,7 @@ static int __maybe_unused
> vsp1_pm_runtime_suspend(struct device *dev)
> >  	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
> >
> >  	rcar_fcp_disable(vsp1->fcp);
> > +	reset_control_assert(vsp1->rstc);
> >
> >  	return 0;
> >  }
> > @@ -631,13 +633,30 @@ static int __maybe_unused
> vsp1_pm_runtime_resume(struct device *dev)
> >  	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
> >  	int ret;
> >
> > +	ret = reset_control_deassert(vsp1->rstc);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	/*
> > +	 * On R-Car Gen2, vsp1 register access after deassert can cause
> > +	 * lock-up. It is a special case and needs some delay to avoid
> > +	 * this lock-up.
> 
> You can reflow this to 80 columns:
> 
> 	 * On R-Car Gen2, vsp1 register access after deassert can cause
> lock-up.
> 	 * It is a special case and needs some delay to avoid this lock-
> up.
> 
> > +	 */

OK, but after adding conditional check for Gen2, it will look like [1]

> > +	udelay(1);
> 
> Is it worth conditioning this on the VSP version to only add the delay
> on Gen2 ?

Will fix this in next version like [1], if it is Ok to everyone.

> 
> With these two small issues addressed,

[1]
        if (vsp1->info) {                                                        
 70 +               /*                                                               
 71 +                * On R-Car Gen2 and RZ/G1, vsp1 register access after deassert  
 72 +                * can cause lock-up.                                            
 73 +                * It is a special case and needs some delay to avoid this       
 74 +                * lock-up.                                                      
 75 +                */                                                              
 76 +               if (vsp1->info->gen == 2)                                        
 77 +                       udelay(1);

Cheers,
Biju               

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> > +
> >  	if (vsp1->info) {
> >  		ret = vsp1_device_init(vsp1);
> >  		if (ret < 0)
> > -			return ret;
> > +			goto done;
> >  	}
> >
> > -	return rcar_fcp_enable(vsp1->fcp);
> > +	ret = rcar_fcp_enable(vsp1->fcp);
> > +
> > +done:
> > +	if (ret < 0)
> > +		reset_control_assert(vsp1->rstc);
> > +
> > +	return ret;
> >  }
> >
> >  static const struct dev_pm_ops vsp1_pm_ops = { @@ -825,6 +844,11 @@
> > static int vsp1_probe(struct platform_device *pdev)
> >  	if (irq < 0)
> >  		return irq;
> >
> > +	vsp1->rstc = devm_reset_control_get_shared(&pdev->dev, NULL);
> > +	if (IS_ERR(vsp1->rstc))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(vsp1->rstc),
> > +				     "failed to get reset control\n");
> > +
> >  	/* FCP (optional). */
> >  	fcp_node = of_parse_phandle(pdev->dev.of_node, "renesas,fcp", 0);
> >  	if (fcp_node) {
> 
> --
> Regards,
> 
> Laurent Pinchart
Laurent Pinchart Aug. 27, 2022, 6:26 p.m. UTC | #3 
Hi Biju,

On Sat, Aug 27, 2022 at 04:07:56PM +0000, Biju Das wrote:
> > Subject: Re: [PATCH v13 2/5] media: renesas: vsp1: Add support to deassert/assert reset line
> > On Thu, Aug 25, 2022 at 02:21:41PM +0100, Biju Das wrote:
> > > As the resets DT property is mandatory, and is present in all .dtsi in
> > > mainline, add support to perform deassert/assert using reference
> > > counted reset handle.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > > ---
> > > v12->v13:
> > >  * Removed unused iopoll.h header file.
> > >  * Added Rb tag from Geert.
> > > v11->v12:
> > >  * Replaced read_poll_timeout_atomic-> udelay(1) as testing on RZ/G1N
> > >    shows this delay is sufficient to avoid lock-up.
> > >  * Removed Rb tags.
> > > v10->v11:
> > >  * To avoid lock-up on R-Car Gen2, added poll for reset status after deassert.
> > > v9->v10:
> > >  * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
> > > v8->v9:
> > >  * No change
> > > v7->v8:
> > >  * No Change
> > > v6->v7:
> > >  * No change
> > > v5->v6:
> > >  * Rebased to media_staging and updated commit header
> > >  * Added Rb tag from Laurent
> > >  * Added forward declaration for struct reset_control
> > >  * Updated vsp1_device_get() with changes suggested by Laurent
> > >  * Updated error message for reset_control_get form ctrl->control.
> > > v4->v5:
> > >  * Added Rb tag from Geert
> > > v3->v4:
> > >  * Restored error check for pm_runtime_resume_and_get and calls
> > >    assert() in case of failure.
> > > v2->v3:
> > >  * Added Rb tag from Philipp
> > >  * If reset_control_deassert() failed, return ret directly.
> > > v1->v2:
> > >  * Used reference counted reset handle to perform deassert/assert
> > > RFC->v1:
> > >  * Added reset support as separate patch
> > >  * Moved rstc just after the bus_master field in struct vsp1_device
> > > RFC:
> > >  *
> > > ---
> > >  drivers/media/platform/renesas/vsp1/vsp1.h    |  2 ++
> > >  .../media/platform/renesas/vsp1/vsp1_drv.c    | 28 +++++++++++++++++-
> > -
> > >  2 files changed, 28 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/media/platform/renesas/vsp1/vsp1.h
> > > b/drivers/media/platform/renesas/vsp1/vsp1.h
> > > index 37cf33c7e6ca..baf898d577ec 100644
> > > --- a/drivers/media/platform/renesas/vsp1/vsp1.h
> > > +++ b/drivers/media/platform/renesas/vsp1/vsp1.h
> > > @@ -22,6 +22,7 @@
> > >  struct clk;
> > >  struct device;
> > >  struct rcar_fcp_device;
> > > +struct reset_control;
> > >
> > >  struct vsp1_drm;
> > >  struct vsp1_entity;
> > > @@ -79,6 +80,7 @@ struct vsp1_device {
> > >  	void __iomem *mmio;
> > >  	struct rcar_fcp_device *fcp;
> > >  	struct device *bus_master;
> > > +	struct reset_control *rstc;
> > >
> > >  	struct vsp1_brx *brs;
> > >  	struct vsp1_brx *bru;
> > > diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > > b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > > index 1f73c48eb738..975e6851735e 100644
> > > --- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > > +++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > > @@ -16,6 +16,7 @@
> > >  #include <linux/of_device.h>
> > >  #include <linux/platform_device.h>
> > >  #include <linux/pm_runtime.h>
> > > +#include <linux/reset.h>
> > >  #include <linux/videodev2.h>
> > >
> > >  #include <media/rcar-fcp.h>
> > > @@ -622,6 +623,7 @@ static int __maybe_unused vsp1_pm_runtime_suspend(struct device *dev)
> > >  	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
> > >
> > >  	rcar_fcp_disable(vsp1->fcp);
> > > +	reset_control_assert(vsp1->rstc);
> > >
> > >  	return 0;
> > >  }
> > > @@ -631,13 +633,30 @@ static int __maybe_unused vsp1_pm_runtime_resume(struct device *dev)
> > >  	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
> > >  	int ret;
> > >
> > > +	ret = reset_control_deassert(vsp1->rstc);
> > > +	if (ret < 0)
> > > +		return ret;
> > > +
> > > +	/*
> > > +	 * On R-Car Gen2, vsp1 register access after deassert can cause
> > > +	 * lock-up. It is a special case and needs some delay to avoid
> > > +	 * this lock-up.
> > 
> > You can reflow this to 80 columns:
> > 
> > 	 * On R-Car Gen2, vsp1 register access after deassert can cause lock-up.
> > 	 * It is a special case and needs some delay to avoid this lock-up.
> > 
> > > +	 */
> 
> OK, but after adding conditional check for Gen2, it will look like [1]
> 
> > > +	udelay(1);
> > 
> > Is it worth conditioning this on the VSP version to only add the delay
> > on Gen2 ?
> 
> Will fix this in next version like [1], if it is Ok to everyone.

Works for me.

> > With these two small issues addressed,
> 
> [1]
>         if (vsp1->info) {                                                        
>  70 +               /*                                                               
>  71 +                * On R-Car Gen2 and RZ/G1, vsp1 register access after deassert  
>  72 +                * can cause lock-up.                                            
>  73 +                * It is a special case and needs some delay to avoid this       
>  74 +                * lock-up.                                                      


As a general rule, flow the text with sentence following each others
without line breaks, all the way to 80 columns. You can break a comment
in paragraphs, and there should then be a blank line between paragraphs.
You can thus write

		 * On R-Car Gen2 and RZ/G1, vsp1 register access after deassert  
		 * can cause lock-up.                                            
		 *
		 * It is a special case and needs some delay to avoid this       
		 * lock-up.                                                      

or

		 * On R-Car Gen2 and RZ/G1, vsp1 register access after deassert
		 * can cause lock-up. It is a special case and needs some delay
		 * to avoid this lock-up.

but not

		 * On R-Car Gen2 and RZ/G1, vsp1 register access after deassert
		 * can cause lock-up.
		 * It is a special case and needs some delay to avoid this
		 * lock-up.

(I think the second option is better here)

>  75 +                */                                                              
>  76 +               if (vsp1->info->gen == 2)                                        
>  77 +                       udelay(1);
> 
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > 
> > > +
> > >  	if (vsp1->info) {
> > >  		ret = vsp1_device_init(vsp1);
> > >  		if (ret < 0)
> > > -			return ret;
> > > +			goto done;
> > >  	}
> > >
> > > -	return rcar_fcp_enable(vsp1->fcp);
> > > +	ret = rcar_fcp_enable(vsp1->fcp);
> > > +
> > > +done:
> > > +	if (ret < 0)
> > > +		reset_control_assert(vsp1->rstc);
> > > +
> > > +	return ret;
> > >  }
> > >
> > >  static const struct dev_pm_ops vsp1_pm_ops = { @@ -825,6 +844,11 @@
> > > static int vsp1_probe(struct platform_device *pdev)
> > >  	if (irq < 0)
> > >  		return irq;
> > >
> > > +	vsp1->rstc = devm_reset_control_get_shared(&pdev->dev, NULL);
> > > +	if (IS_ERR(vsp1->rstc))
> > > +		return dev_err_probe(&pdev->dev, PTR_ERR(vsp1->rstc),
> > > +				     "failed to get reset control\n");
> > > +
> > >  	/* FCP (optional). */
> > >  	fcp_node = of_parse_phandle(pdev->dev.of_node, "renesas,fcp", 0);
diff mbox series

Patch

diff --git a/drivers/media/platform/renesas/vsp1/vsp1.h b/drivers/media/platform/renesas/vsp1/vsp1.h
index 37cf33c7e6ca..baf898d577ec 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1.h
+++ b/drivers/media/platform/renesas/vsp1/vsp1.h
@@ -22,6 +22,7 @@ 
 struct clk;
 struct device;
 struct rcar_fcp_device;
+struct reset_control;
 
 struct vsp1_drm;
 struct vsp1_entity;
@@ -79,6 +80,7 @@  struct vsp1_device {
 	void __iomem *mmio;
 	struct rcar_fcp_device *fcp;
 	struct device *bus_master;
+	struct reset_control *rstc;
 
 	struct vsp1_brx *brs;
 	struct vsp1_brx *bru;
diff --git a/drivers/media/platform/renesas/vsp1/vsp1_drv.c b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
index 1f73c48eb738..975e6851735e 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
@@ -16,6 +16,7 @@ 
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/videodev2.h>
 
 #include <media/rcar-fcp.h>
@@ -622,6 +623,7 @@  static int __maybe_unused vsp1_pm_runtime_suspend(struct device *dev)
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 
 	rcar_fcp_disable(vsp1->fcp);
+	reset_control_assert(vsp1->rstc);
 
 	return 0;
 }
@@ -631,13 +633,30 @@  static int __maybe_unused vsp1_pm_runtime_resume(struct device *dev)
 	struct vsp1_device *vsp1 = dev_get_drvdata(dev);
 	int ret;
 
+	ret = reset_control_deassert(vsp1->rstc);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * On R-Car Gen2, vsp1 register access after deassert can cause
+	 * lock-up. It is a special case and needs some delay to avoid
+	 * this lock-up.
+	 */
+	udelay(1);
+
 	if (vsp1->info) {
 		ret = vsp1_device_init(vsp1);
 		if (ret < 0)
-			return ret;
+			goto done;
 	}
 
-	return rcar_fcp_enable(vsp1->fcp);
+	ret = rcar_fcp_enable(vsp1->fcp);
+
+done:
+	if (ret < 0)
+		reset_control_assert(vsp1->rstc);
+
+	return ret;
 }
 
 static const struct dev_pm_ops vsp1_pm_ops = {
@@ -825,6 +844,11 @@  static int vsp1_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return irq;
 
+	vsp1->rstc = devm_reset_control_get_shared(&pdev->dev, NULL);
+	if (IS_ERR(vsp1->rstc))
+		return dev_err_probe(&pdev->dev, PTR_ERR(vsp1->rstc),
+				     "failed to get reset control\n");
+
 	/* FCP (optional). */
 	fcp_node = of_parse_phandle(pdev->dev.of_node, "renesas,fcp", 0);
 	if (fcp_node) {