Re: [PATCH] phy: renesas: rcar-gen3-usb2: Add suspend/resume support

[Neil Armstrong <neil.armstrong@linaro.org>]

On 11/6/25 15:41, Claudiu wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> The Renesas RZ/G3S supports a power saving mode where power to most of the
> SoC components is turned off. The USB PHY is among these components.
> Because of this the settings applied in driver probe need to be executed
> also on resume path. On suspend path only reset signal need to be asserted.
> Add suspend/resume support.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> ---
> 
> This patch is built on top of patches 1/7, 2/7 at [1]
> 
> [1] https://lore.kernel.org/all/20251023135810.1688415-2-claudiu.beznea.uj@bp.renesas.com
> 
>   drivers/phy/renesas/phy-rcar-gen3-usb2.c | 66 +++++++++++++++++-------
>   1 file changed, 47 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> index a38ead7c8055..3c063e4dea41 100644
> --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> @@ -132,6 +132,7 @@ struct rcar_gen3_chan {
>   	struct device *dev;	/* platform_device's device */
>   	const struct rcar_gen3_phy_drv_data *phy_data;
>   	struct extcon_dev *extcon;
> +	struct reset_control *rstc;
>   	struct rcar_gen3_phy rphys[NUM_OF_PHYS];
>   	struct regulator *vbus;
>   	struct work_struct work;
> @@ -778,35 +779,24 @@ static void rcar_gen3_reset_assert(void *data)
>   static int rcar_gen3_phy_usb2_init_bus(struct rcar_gen3_chan *channel)
>   {
>   	struct device *dev = channel->dev;
> -	struct reset_control *rstc;
>   	int ret;
>   	u32 val;
>   
> -	rstc = devm_reset_control_array_get_shared(dev);
> -	if (IS_ERR(rstc))
> -		return PTR_ERR(rstc);
> +	if (!channel->phy_data->init_bus)
> +		return 0;
>   
>   	ret = pm_runtime_resume_and_get(dev);
>   	if (ret)
>   		return ret;
>   
> -	ret = reset_control_deassert(rstc);
> -	if (ret)
> -		goto rpm_put;
> -
> -	ret = devm_add_action_or_reset(dev, rcar_gen3_reset_assert, rstc);
> -	if (ret)
> -		goto rpm_put;
> -
>   	val = readl(channel->base + USB2_AHB_BUS_CTR);
>   	val &= ~USB2_AHB_BUS_CTR_MBL_MASK;
>   	val |= USB2_AHB_BUS_CTR_MBL_INCR4;
>   	writel(val, channel->base + USB2_AHB_BUS_CTR);
>   
> -rpm_put:
>   	pm_runtime_put(dev);
>   
> -	return ret;
> +	return 0;
>   }
>   
>   static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
> @@ -846,6 +836,18 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
>   		}
>   	}
>   
> +	channel->rstc = devm_reset_control_array_get_optional_shared(dev);
> +	if (IS_ERR(channel->rstc))
> +		return PTR_ERR(channel->rstc);
> +
> +	ret = reset_control_deassert(channel->rstc);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_add_action_or_reset(dev, rcar_gen3_reset_assert, channel->rstc);
> +	if (ret)
> +		return ret;
> +
>   	/*
>   	 * devm_phy_create() will call pm_runtime_enable(&phy->dev);
>   	 * And then, phy-core will manage runtime pm for this device.
> @@ -861,11 +863,9 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
>   	platform_set_drvdata(pdev, channel);
>   	channel->dev = dev;
>   
> -	if (channel->phy_data->init_bus) {
> -		ret = rcar_gen3_phy_usb2_init_bus(channel);
> -		if (ret)
> -			goto error;
> -	}

I don't see why you changed the logic of calling rcar_gen3_phy_usb2_init_bus(),
moving the reset setup and handling should be enough, no ?

Neil

> +	ret = rcar_gen3_phy_usb2_init_bus(channel);
> +	if (ret)
> +		goto error;
>   
>   	spin_lock_init(&channel->lock);
>   	for (i = 0; i < NUM_OF_PHYS; i++) {
> @@ -936,10 +936,38 @@ static void rcar_gen3_phy_usb2_remove(struct platform_device *pdev)
>   	pm_runtime_disable(&pdev->dev);
>   };
>   
> +static int rcar_gen3_phy_usb2_suspend(struct device *dev)
> +{
> +	struct rcar_gen3_chan *channel = dev_get_drvdata(dev);
> +
> +	return reset_control_assert(channel->rstc);
> +}
> +
> +static int rcar_gen3_phy_usb2_resume(struct device *dev)
> +{
> +	struct rcar_gen3_chan *channel = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = reset_control_deassert(channel->rstc);
> +	if (ret)
> +		return ret;
> +
> +	ret = rcar_gen3_phy_usb2_init_bus(channel);
> +	if (ret)
> +		reset_control_assert(channel->rstc);
> +
> +	return ret;
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(rcar_gen3_phy_usb2_pm_ops,
> +				rcar_gen3_phy_usb2_suspend,
> +				rcar_gen3_phy_usb2_resume);
> +
>   static struct platform_driver rcar_gen3_phy_usb2_driver = {
>   	.driver = {
>   		.name		= "phy_rcar_gen3_usb2",
>   		.of_match_table	= rcar_gen3_phy_usb2_match_table,
> +		.pm		= pm_ptr(&rcar_gen3_phy_usb2_pm_ops),
>   	},
>   	.probe	= rcar_gen3_phy_usb2_probe,
>   	.remove = rcar_gen3_phy_usb2_remove,


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