[PATCH 2/2] phy: fsl-imx8mq-usb: handle resettable hubs

[Jun Li]

Hi,
> -----Original Message-----
> From: Adrien Grassein <adrien.grassein at gmail.com>
> Sent: Friday, January 29, 2021 6:13 AM
> Cc: kishon at ti.com; vkoul at kernel.org; robh+dt at kernel.org; shawnguo at kernel.org;
> s.hauer at pengutronix.de; kernel at pengutronix.de; festevam at gmail.com; dl-linux-imx
> <linux-imx at nxp.com>; rikard.falkeborn at gmail.com; Peter Chen <peter.chen at nxp.com>;
> Jun Li <jun.li at nxp.com>; linux-kernel at vger.kernel.org;
> devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org; Adrien
> Grassein <adrien.grassein at gmail.com>
> Subject: [PATCH 2/2] phy: fsl-imx8mq-usb: handle resettable hubs
> 
> Add an optional GPIO in the dtb description that will be used to reset the connected
> hub (if any).

Put the external usb device reset in host phy driver, this may not
the right way, there was some attempts to handle this case(on board
hub), I am not sure what's the status now.

Li Jun

> 
> Signed-off-by: Adrien Grassein <adrien.grassein at gmail.com>
> ---
>  drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> index a29b4a6f7c24..00abf7814fe9 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> @@ -4,6 +4,7 @@
>  #include <linux/bitfield.h>
>  #include <linux/clk.h>
>  #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/io.h>
>  #include <linux/module.h>
>  #include <linux/of_platform.h>
> @@ -36,6 +37,7 @@ struct imx8mq_usb_phy {
>  	struct clk *clk;
>  	void __iomem *base;
>  	struct regulator *vbus;
> +	struct gpio_desc *reset_gpio;
>  };
> 
>  static int imx8mq_usb_phy_init(struct phy *phy) @@ -111,6 +113,9 @@ static int
> imx8mq_phy_power_on(struct phy *phy)
>  	if (ret)
>  		return ret;
> 
> +	if (imx_phy->reset_gpio)
> +		gpiod_set_value_cansleep(imx_phy->reset_gpio, 0);
> +
>  	return clk_prepare_enable(imx_phy->clk);  }
> 
> @@ -120,6 +125,8 @@ static int imx8mq_phy_power_off(struct phy *phy)
> 
>  	clk_disable_unprepare(imx_phy->clk);
>  	regulator_disable(imx_phy->vbus);
> +	if (imx_phy->reset_gpio)
> +		gpiod_set_value_cansleep(imx_phy->reset_gpio, 1);
> 
>  	return 0;
>  }
> @@ -153,6 +160,7 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct imx8mq_usb_phy *imx_phy;
>  	const struct phy_ops *phy_ops;
> +	int ret;
> 
>  	imx_phy = devm_kzalloc(dev, sizeof(*imx_phy), GFP_KERNEL);
>  	if (!imx_phy)
> @@ -180,6 +188,15 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev)
>  	if (IS_ERR(imx_phy->vbus))
>  		return PTR_ERR(imx_phy->vbus);
> 
> +	imx_phy->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(imx_phy->reset_gpio)) {
> +		ret = PTR_ERR(imx_phy->reset_gpio);
> +		if (ret == -ENXIO || ret == -ENODEV)
> +			imx_phy->reset_gpio = NULL;
> +		else
> +			return PTR_ERR(imx_phy->reset_gpio);
> +	}
> +
>  	phy_set_drvdata(imx_phy->phy, imx_phy);
> 
>  	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> --
> 2.25.1