phy: tegra: xusb: Tegra210 host mode VBUS control

To support XUSB host controller ELPG, this commit moves VBUS control
.phy_power_on()/.phy_power_off() to .phy_init()/.phy_exit().
When XUSB host controller enters ELPG, host driver invokes
.phy_power_off(), VBUS should remain ON so that USB devices will not
disconnect. VBUS can be turned OFF when host driver invokes
.phy_exit() which indicates disabling a USB port.
Signed-off-by: NJC Kuo <jckuo@nvidia.com>
Acked-By: NVinod Koul <vkoul@kernel.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/phy/tegra/xusb-tegra210.c

@@ -1799,8 +1799,25 @@ static int tegra210_usb2_phy_init(struct phy *phy)
 {
 	struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
 	struct tegra_xusb_padctl *padctl = lane->pad->padctl;
+	unsigned int index = lane->index;
+	struct tegra_xusb_usb2_port *port;
+	int err;
 	u32 value;
 
+	port = tegra_xusb_find_usb2_port(padctl, index);
+	if (!port) {
+		dev_err(&phy->dev, "no port found for USB2 lane %u\n", index);
+		return -ENODEV;
+	}
+
+	if (port->supply && port->mode == USB_DR_MODE_HOST) {
+		err = regulator_enable(port->supply);
+		if (err)
+			return err;
+	}
+
+	mutex_lock(&padctl->lock);
+
 	value = padctl_readl(padctl, XUSB_PADCTL_USB2_PAD_MUX);
 	value &= ~(XUSB_PADCTL_USB2_PAD_MUX_USB2_BIAS_PAD_MASK <<
 		   XUSB_PADCTL_USB2_PAD_MUX_USB2_BIAS_PAD_SHIFT);
@@ -1808,11 +1825,30 @@ static int tegra210_usb2_phy_init(struct phy *phy)
 		 XUSB_PADCTL_USB2_PAD_MUX_USB2_BIAS_PAD_SHIFT;
 	padctl_writel(padctl, value, XUSB_PADCTL_USB2_PAD_MUX);
 
+	mutex_unlock(&padctl->lock);
+
 	return 0;
 }
 
 static int tegra210_usb2_phy_exit(struct phy *phy)
 {
+	struct tegra_xusb_lane *lane = phy_get_drvdata(phy);
+	struct tegra_xusb_padctl *padctl = lane->pad->padctl;
+	struct tegra_xusb_usb2_port *port;
+	int err;
+
+	port = tegra_xusb_find_usb2_port(padctl, lane->index);
+	if (!port) {
+		dev_err(&phy->dev, "no port found for USB2 lane %u\n", lane->index);
+		return -ENODEV;
+	}
+
+	if (port->supply && port->mode == USB_DR_MODE_HOST) {
+		err = regulator_disable(port->supply);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
@@ -1933,6 +1969,8 @@ static int tegra210_usb2_phy_power_on(struct phy *phy)
 
 	priv = to_tegra210_xusb_padctl(padctl);
 
+	mutex_lock(&padctl->lock);
+
 	if (port->usb3_port_fake != -1) {
 		value = padctl_readl(padctl, XUSB_PADCTL_SS_PORT_MAP);
 		value &= ~XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP_MASK(
@@ -2026,14 +2064,6 @@ static int tegra210_usb2_phy_power_on(struct phy *phy)
 	padctl_writel(padctl, value,
 		      XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
 
-	if (port->supply && port->mode == USB_DR_MODE_HOST) {
-		err = regulator_enable(port->supply);
-		if (err)
-			return err;
-	}
-
-	mutex_lock(&padctl->lock);
-
 	if (pad->enable > 0) {
 		pad->enable++;
 		mutex_unlock(&padctl->lock);
@@ -2042,7 +2072,7 @@ static int tegra210_usb2_phy_power_on(struct phy *phy)
 
 	err = clk_prepare_enable(pad->clk);
 	if (err)
-		goto disable_regulator;
+		goto out;
 
 	value = padctl_readl(padctl, XUSB_PADCTL_USB2_BIAS_PAD_CTL1);
 	value &= ~((XUSB_PADCTL_USB2_BIAS_PAD_CTL1_TRK_START_TIMER_MASK <<
@@ -2074,8 +2104,7 @@ static int tegra210_usb2_phy_power_on(struct phy *phy)
 
 	return 0;
 
-disable_regulator:
-	regulator_disable(port->supply);
+out:
 	mutex_unlock(&padctl->lock);
 	return err;
 }
@@ -2134,7 +2163,6 @@ static int tegra210_usb2_phy_power_off(struct phy *phy)
 	padctl_writel(padctl, value, XUSB_PADCTL_USB2_BIAS_PAD_CTL0);
 
 out:
-	regulator_disable(port->supply);
 	mutex_unlock(&padctl->lock);
 	return 0;
 }