[PATCH 3/3] phy: sun4i-usb: Support VBUS detection via power supply

[Samuel Holland <samuel@sholland.org>]

The device tree binding provides for getting VBUS state from a device
referenced by phandle, as an optional alternative to using a GPIO. In
U-Boot, where there is no power supply class, this VBUS detection will
be implemented using a regulator device and its get_enable method.
Let's hook this up to the PHY driver.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 drivers/phy/allwinner/Kconfig         | 1 +
 drivers/phy/allwinner/phy-sun4i-usb.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/phy/allwinner/Kconfig b/drivers/phy/allwinner/Kconfig
index dba3bae61c4..aa9d0e7e6a5 100644
--- a/drivers/phy/allwinner/Kconfig
+++ b/drivers/phy/allwinner/Kconfig
@@ -4,6 +4,7 @@
 config PHY_SUN4I_USB
 	bool "Allwinner Sun4I USB PHY driver"
 	depends on ARCH_SUNXI
+	select DM_REGULATOR
 	select PHY
 	help
 	  Enable this to support the transceiver that is part of Allwinner
diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
index 827ecd70f27..ab2a5d17fcf 100644
--- a/drivers/phy/allwinner/phy-sun4i-usb.c
+++ b/drivers/phy/allwinner/phy-sun4i-usb.c
@@ -26,6 +26,7 @@
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <power/regulator.h>
 
 #define REG_ISCR			0x00
 #define REG_PHYCTL_A10			0x04
@@ -137,6 +138,7 @@ struct sun4i_usb_phy_data {
 	void __iomem *base;
 	const struct sun4i_usb_phy_cfg *cfg;
 	struct sun4i_usb_phy_plat *usb_phy;
+	struct udevice *vbus_power_supply;
 };
 
 static int initial_usb_scan_delay = CONFIG_INITIAL_USB_SCAN_DELAY;
@@ -404,6 +406,8 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy)
 			mdelay(100);
 			err = gpio_get_value(usb_phy->gpio_vbus_det);
 		}
+	} else if (data->vbus_power_supply) {
+		err = regulator_get_enable(data->vbus_power_supply);
 	}
 
 	return err;
@@ -447,6 +451,9 @@ static int sun4i_usb_phy_probe(struct udevice *dev)
 	if (IS_ERR(data->base))
 		return PTR_ERR(data->base);
 
+	device_get_supply_regulator(dev, "usb0_vbus_power-supply",
+				    &data->vbus_power_supply);
+
 	data->usb_phy = plat;
 	for (i = 0; i < data->cfg->num_phys; i++) {
 		struct sun4i_usb_phy_plat *phy = &plat[i];
-- 
2.31.1