[PATCH v2] phy: phy-imx8mq-usb: add vbus regulator support

[Tim Harvey]

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 <thar...@gateworks.com>
Reviewed-by: Adam Ford <aford...@gmail.com>
---
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 | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/phy-imx8mq-usb.c b/drivers/phy/phy-imx8mq-usb.c
index 69f01de55538..53099436b04b 100644
--- a/drivers/phy/phy-imx8mq-usb.c
+++ b/drivers/phy/phy-imx8mq-usb.c
@@ -14,6 +14,7 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <clk.h>
+#include <power/regulator.h>
 
 #define PHY_CTRL0                      0x0
 #define PHY_CTRL0_REF_SSP_EN           BIT(2)
@@ -81,6 +82,7 @@ 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[] = {
@@ -172,10 +174,10 @@ 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");
@@ -183,6 +185,14 @@ 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(imx_phy->vbus_supply, true);
+               if (ret) {
+                       pr_err("Failed to enable VBUS regulator: %d\n", ret);
+                       return ret;
+               }
+       }
+
        /* Disable rx term override */
        value = readl(imx_phy->base + PHY_CTRL6);
        value &= ~PHY_CTRL6_RXTERM_OVERRIDE_SEL;
@@ -195,6 +205,7 @@ 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);
+       __maybe_unused int ret;
        u32 value;
 
        /* Override rx term to be 0 */
@@ -206,6 +217,14 @@ 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(imx_phy->vbus_supply, false);
+               if (ret) {
+                       pr_err("Failed to disable VBUS regulator: %d\n", ret);
+                       return ret;
+               }
+       }
+
        return 0;
 }
 
@@ -224,6 +243,7 @@ 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 +252,6 @@ 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);
@@ -242,6 +261,15 @@ int imx8mq_usb_phy_probe(struct udevice *dev)
        }
 #endif
 
+       if (CONFIG_IS_ENABLED(DM_REGULATOR)) {
+               ret = device_get_supply_regulator(dev, "vbus-supply",
+                                                 &priv->vbus_supply);
+               if (ret && ret != -ENOENT) {
+                       pr_err("Failed to get VBUS regulator: %d\n", ret);
+                       return ret;
+               }
+       }
+
        return 0;
 }
 
-- 
2.25.1