[PATCH v6 1/2] phy: phy-imx8mq-usb: add vbus regulator support

[Marek Vasut]

On 7/13/23 19:11, 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>
> ---
> 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
> ---
>   drivers/phy/phy-imx8mq-usb.c | 37 +++++++++++++++++++++++++++++++++---
>   1 file changed, 34 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/phy/phy-imx8mq-usb.c b/drivers/phy/phy-imx8mq-usb.c
> index 69f01de55538..0ab7965df2ff 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 +186,24 @@ 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:
> +	clk_disable(&imx_phy->phy_clk);

This would fail if CLK is not enabled , or cause clock imbalance.

(you would avoid this issue if you were to swap the two patches, or add
+if CONFIG_IS_ENABLED(CLK)
   clk_disable(...);

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