[PATCH v4] phy: phy-imx8mq-usb: add vbus regulator support

[Tim Harvey]

On Mon, Jul 10, 2023 at 4:18 PM Marek Vasut <marex at denx.de> wrote:
>
> On 7/11/23 00:49, 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>
> > ---
> > 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 | 39 ++++++++++++++++++++++++++++++++++--
> >   1 file changed, 37 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/phy/phy-imx8mq-usb.c b/drivers/phy/phy-imx8mq-usb.c
> > index 69f01de55538..6cbcb2338cfe 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 +83,9 @@ struct imx8mq_usb_phy {
> >   #endif
> >       void __iomem *base;
> >       enum imx8mpq_phy_type type;
> > +#if CONFIG_IS_ENABLED(DM_REGULATOR)
> > +     struct udevice *vbus_supply;
> > +#endif
> >   };
> >
> >   static const struct udevice_id imx8mq_usb_phy_of_match[] = {
> > @@ -172,10 +177,10 @@ 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);
> > +     __maybe_unused int ret;
> >       u32 value;
> >
> >   #if CONFIG_IS_ENABLED(CLK)
> > -     int ret;
> >       ret = clk_enable(&imx_phy->phy_clk);
> >       if (ret) {
> >               printf("Failed to enable usb phy clock\n");
> > @@ -183,18 +188,31 @@ 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);
> > +     return ret;
> >   }
> >
> >   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);
> > +     __maybe_unused int ret;
> >       u32 value;
> >
> >       /* Override rx term to be 0 */
> > @@ -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);
> > +     __maybe_unused int ret;
> >
> >       priv->type = dev_get_driver_data(dev);
> >       priv->base = dev_read_addr_ptr(dev);
> > @@ -232,7 +259,6 @@ int imx8mq_usb_phy_probe(struct udevice *dev)
> >               return -EINVAL;
> >
> >   #if CONFIG_IS_ENABLED(CLK)
> > -     int ret;
>
> I _think_ if you were to convert this #if CONFIG...() to if
> (CONFIG...()), you would be able to drop the __maybe_unused . Separate
> conversion patch would be better though.

Hi Marek,

Yes, I thought about that as well and felt it should be a separate
followup cleanup patch.

Best regards,

Tim