[PATCH v5] 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.

While we are at it replace '#if CONFIG_IS_ENABLED(CLK)' with
'if (CONFIG_IS_ENABLED(CLK))' as a cleanup.

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>
---
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 | 68 +++++++++++++++++++++++++-----------
 1 file changed, 48 insertions(+), 20 deletions(-)

diff --git a/drivers/phy/phy-imx8mq-usb.c b/drivers/phy/phy-imx8mq-usb.c
index 69f01de55538..532b0235e2bc 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)
@@ -76,11 +78,10 @@ enum imx8mpq_phy_type {
 };
 
 struct imx8mq_usb_phy {
-#if CONFIG_IS_ENABLED(CLK)
 	struct clk phy_clk;
-#endif
 	void __iomem *base;
 	enum imx8mpq_phy_type type;
+	struct udevice *vbus_supply;
 };
 
 static const struct udevice_id imx8mq_usb_phy_of_match[] = {
@@ -172,16 +173,24 @@ 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);
+	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");
-		return ret;
+	if (CONFIG_IS_ENABLED(CLK)) {
+		ret = clk_enable(&imx_phy->phy_clk);
+		if (ret) {
+			printf("Failed to enable usb phy clock\n");
+			return ret;
+		}
+	}
+
+	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;
+		}
 	}
-#endif
 
 	/* Disable rx term override */
 	value = readl(imx_phy->base + PHY_CTRL6);
@@ -189,12 +198,17 @@ static int imx8mq_usb_phy_power_on(struct phy *usb_phy)
 	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);
+	int ret;
 	u32 value;
 
 	/* Override rx term to be 0 */
@@ -202,9 +216,16 @@ static int imx8mq_usb_phy_power_off(struct phy *usb_phy)
 	value |= PHY_CTRL6_RXTERM_OVERRIDE_SEL;
 	writel(value, imx_phy->base + PHY_CTRL6);
 
-#if CONFIG_IS_ENABLED(CLK)
-	clk_disable(&imx_phy->phy_clk);
-#endif
+	if (CONFIG_IS_ENABLED(CLK))
+		clk_disable(&imx_phy->phy_clk);
+
+	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 +245,7 @@ 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);
@@ -231,16 +253,22 @@ int imx8mq_usb_phy_probe(struct udevice *dev)
 	if (!priv->base)
 		return -EINVAL;
 
-#if CONFIG_IS_ENABLED(CLK)
-	int ret;
+	if (CONFIG_IS_ENABLED(CLK)) {
+		ret = clk_get_by_name(dev, "phy", &priv->phy_clk);
+		if (ret) {
+			printf("Failed to get usb phy clock\n");
+			return ret;
+		}
+	}
 
-	/* Assigned clock already set clock */
-	ret = clk_get_by_name(dev, "phy", &priv->phy_clk);
-	if (ret) {
-		printf("Failed to get usb phy clock\n");
-		return ret;
+	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;
+		}
 	}
-#endif
 
 	return 0;
 }
-- 
2.25.1