[PATCH v7 1/2] phy: phy-imx8mq-usb: add vbus regulator support

[Marcel Ziswiler]

Hi Tim

Thanks!

On Thu, 2023-07-13 at 11:56 -0700, Tim Harvey wrote:
> Add support for enabling and disabling vbus-supply regulator found
> on several imx8mp boards in the usb3_phy0 and usb3_phy1 nodes.
> 
> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> Reviewed-by: Adam Ford <aford173 at gmail.com>
> Reviewed-by: Marek Vasut <marex at denx.de>

Tested-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>

> ---
> v7:
>  - add #ifdef protection around clk_disable error path
> 
> v6:
>  - move changes to clk to separate patch
>  - sort new vars in reverse christmas tree style
> 
> v5:
>  - remove #if CONFIG_IS_ENABLED around struct members
>    (you can not conditionally include if using if (CONFIG_IS_ENABLED(foo)) )
>  - replace clk '#if CONFIG_IS_ENABLED(CLK)' with 'if (CONFIG_IS_ENABLED(CLK))'
> 
> v4:
>  - use regulator_set_enable_if_allowed to handle regulator reference
> counting
>    errors
>  - added Marek's rb tag
> 
> v3:
>  - change pr_err to dev_err
>  - add #if CONFIG_IS_ENABLED around vbus_supply in struct
>  - add fail path to disable clock if regulator enable failed
> 
> v2:
>  - protect ret with __maybe_unused in case CONFIG_CLK and
>    CONFIG_DM_REGULATOR not defined
>  - add error prints on failures
>  - add Adam's rb tag
> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> ---
>  drivers/phy/phy-imx8mq-usb.c | 39 +++++++++++++++++++++++++++++++++---
>  1 file changed, 36 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/phy/phy-imx8mq-usb.c b/drivers/phy/phy-imx8mq-usb.c
> index 69f01de55538..9fa78ef4da3d 100644
> --- a/drivers/phy/phy-imx8mq-usb.c
> +++ b/drivers/phy/phy-imx8mq-usb.c
> @@ -14,6 +14,8 @@
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <clk.h>
> +#include <dm/device_compat.h>
> +#include <power/regulator.h>
>  
>  #define PHY_CTRL0                      0x0
>  #define PHY_CTRL0_REF_SSP_EN           BIT(2)
> @@ -81,6 +83,7 @@ struct imx8mq_usb_phy {
>  #endif
>         void __iomem *base;
>         enum imx8mpq_phy_type type;
> +       struct udevice *vbus_supply;
>  };
>  
>  static const struct udevice_id imx8mq_usb_phy_of_match[] = {
> @@ -173,9 +176,9 @@ static int imx8mq_usb_phy_power_on(struct phy *usb_phy)
>         struct udevice *dev = usb_phy->dev;
>         struct imx8mq_usb_phy *imx_phy = dev_get_priv(dev);
>         u32 value;
> +       int ret;
>  
>  #if CONFIG_IS_ENABLED(CLK)
> -       int ret;
>         ret = clk_enable(&imx_phy->phy_clk);
>         if (ret) {
>                 printf("Failed to enable usb phy clock\n");
> @@ -183,12 +186,26 @@ static int imx8mq_usb_phy_power_on(struct phy *usb_phy)
>         }
>  #endif
>  
> +       if (CONFIG_IS_ENABLED(DM_REGULATOR) && imx_phy->vbus_supply) {
> +               ret = regulator_set_enable_if_allowed(imx_phy->vbus_supply, true);
> +               if (ret && ret != -ENOSYS) {
> +                       dev_err(dev, "Failed to enable VBUS regulator: %d\n", ret);
> +                       goto err;
> +               }
> +       }
> +
>         /* Disable rx term override */
>         value = readl(imx_phy->base + PHY_CTRL6);
>         value &= ~PHY_CTRL6_RXTERM_OVERRIDE_SEL;
>         writel(value, imx_phy->base + PHY_CTRL6);
>  
>         return 0;
> +
> +err:
> +#if CONFIG_IS_ENABLED(CLK)
> +       clk_disable(&imx_phy->phy_clk);
> +#endif
> +       return ret;
>  }
>  
>  static int imx8mq_usb_phy_power_off(struct phy *usb_phy)
> @@ -196,6 +213,7 @@ static int imx8mq_usb_phy_power_off(struct phy *usb_phy)
>         struct udevice *dev = usb_phy->dev;
>         struct imx8mq_usb_phy *imx_phy = dev_get_priv(dev);
>         u32 value;
> +       int ret;
>  
>         /* Override rx term to be 0 */
>         value = readl(imx_phy->base + PHY_CTRL6);
> @@ -206,6 +224,14 @@ static int imx8mq_usb_phy_power_off(struct phy *usb_phy)
>         clk_disable(&imx_phy->phy_clk);
>  #endif
>  
> +       if (CONFIG_IS_ENABLED(DM_REGULATOR) && imx_phy->vbus_supply) {
> +               ret = regulator_set_enable_if_allowed(imx_phy->vbus_supply, false);
> +               if (ret && ret != -ENOSYS) {
> +                       dev_err(dev, "Failed to disable VBUS regulator: %d\n", ret);
> +                       return ret;
> +               }
> +       }
> +
>         return 0;
>  }
>  
> @@ -224,6 +250,7 @@ struct phy_ops imx8mq_usb_phy_ops = {
>  int imx8mq_usb_phy_probe(struct udevice *dev)
>  {
>         struct imx8mq_usb_phy *priv = dev_get_priv(dev);
> +       int ret;
>  
>         priv->type = dev_get_driver_data(dev);
>         priv->base = dev_read_addr_ptr(dev);
> @@ -232,8 +259,6 @@ int imx8mq_usb_phy_probe(struct udevice *dev)
>                 return -EINVAL;
>  
>  #if CONFIG_IS_ENABLED(CLK)
> -       int ret;
> -
>         /* Assigned clock already set clock */
>         ret = clk_get_by_name(dev, "phy", &priv->phy_clk);
>         if (ret) {
> @@ -241,6 +266,14 @@ int imx8mq_usb_phy_probe(struct udevice *dev)
>                 return ret;
>         }
>  #endif
> +       if (CONFIG_IS_ENABLED(DM_REGULATOR)) {
> +               ret = device_get_supply_regulator(dev, "vbus-supply",
> +                                                 &priv->vbus_supply);
> +               if (ret && ret != -ENOENT) {
> +                       dev_err(dev, "Failed to get VBUS regulator: %d\n", ret);
> +                       return ret;
> +               }
> +       }
>  
>         return 0;
>  }