Re: [PATCH 07/10] media: rcar-fcp: Handle resets

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Thu, Sep 17, 2026 at 09:04:46PM +0900, Paul Elder wrote:
> On some versions of the FCP, such as the one on the X5H, reset control
> is required to operate the FCP. Add support for handling resets
> optionally, to continue supporting versions that do not require it.
> 
> Signed-off-by: Paul Elder <paul.elder+renesas@ideasonboard.com>
> ---
>  drivers/media/platform/renesas/rcar-fcp.c | 34 +++++++++++++++++++++++++++++--
>  1 file changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar-fcp.c b/drivers/media/platform/renesas/rcar-fcp.c
> index d99b3ff976e80f275af19e5dc02c6e1de98c38a3..15bcbbda3b853f71780aae876f6440b33addf193 100644
> --- a/drivers/media/platform/renesas/rcar-fcp.c
> +++ b/drivers/media/platform/renesas/rcar-fcp.c
> @@ -18,6 +18,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/property.h>
> +#include <linux/reset.h>
>  #include <linux/slab.h>
>  
>  #include <media/rcar-fcp.h>
> @@ -63,6 +64,8 @@
>  #define RCAR_FCP_REG_BA_REF_Y2			0x0118
>  #define RCAR_FCP_REG_BA_REF_C			0x011c
>  
> +struct reset_control;
> +

Not needed, you include linux/reset.h.

>  enum rcar_fcp_type {
>  	RCAR_FCPF,
>  	RCAR_FCPV,
> @@ -73,6 +76,7 @@ struct rcar_fcp_device {
>  	struct device *dev;
>  	void __iomem *base;
>  	enum rcar_fcp_type type;
> +	struct reset_control *rstc;
>  };
>  
>  static LIST_HEAD(fcp_devices);
> @@ -262,12 +266,19 @@ static int rcar_fcp_probe(struct platform_device *pdev)
>  	fcp->dev = &pdev->dev;
>  	fcp->type = (enum rcar_fcp_type)device_get_match_data(&pdev->dev);
>  
> +	platform_set_drvdata(pdev, fcp);
> +
>  	fcp->base = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(fcp->base))
>  		return PTR_ERR(fcp->base);
>  
>  	dma_set_max_seg_size(fcp->dev, UINT_MAX);
>  
> +	fcp->rstc = devm_reset_control_get_optional(&pdev->dev, NULL);
> +	if (IS_ERR(fcp->rstc))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(fcp->rstc),
> +				     "failed to get reset control\n");
> +
>  	pm_runtime_enable(&pdev->dev);
>  	ret = pm_runtime_resume_and_get(&pdev->dev);
>  	if (ret < 0)
> @@ -283,8 +294,6 @@ static int rcar_fcp_probe(struct platform_device *pdev)
>  	list_add_tail(&fcp->list, &fcp_devices);
>  	mutex_unlock(&fcp_lock);
>  
> -	platform_set_drvdata(pdev, fcp);
> -
>  	return 0;
>  
>  error_pm_put:
> @@ -305,11 +314,32 @@ static void rcar_fcp_remove(struct platform_device *pdev)
>  	pm_runtime_disable(&pdev->dev);
>  }
>  
> +static int fcp_pm_runtime_suspend(struct device *dev)
> +{
> +	struct rcar_fcp_device *fcp = dev_get_drvdata(dev);
> +
> +	reset_control_assert(fcp->rstc);

No need for error checking ?

> +	return 0;
> +}
> +
> +static int fcp_pm_runtime_resume(struct device *dev)
> +{
> +	struct rcar_fcp_device *fcp = dev_get_drvdata(dev);
> +
> +	reset_control_deassert(fcp->rstc);

Same here.

Otherwise this looks good, but please move it before patch 06/10 as I
would like to upstream this without 06/10.

> +	return 0;
> +}
> +
> +static const struct dev_pm_ops fcp_pm_ops = {
> +	RUNTIME_PM_OPS(fcp_pm_runtime_suspend, fcp_pm_runtime_resume, NULL)
> +};
> +
>  static struct platform_driver rcar_fcp_platform_driver = {
>  	.probe		= rcar_fcp_probe,
>  	.remove		= rcar_fcp_remove,
>  	.driver		= {
>  		.name	= "rcar-fcp",
> +		.pm = pm_ptr(&fcp_pm_ops),
>  		.of_match_table = rcar_fcp_of_match,
>  		.suppress_bind_attrs = true,
>  	},
> 

-- 
Regards,

Laurent Pinchart