phy: tegra: xusb: reset VBUS & ID OVERRIDE

Observed VBUS_OVERRIDE & ID_OVERRIDE might be programmed
with unexpected value prior to XUSB PADCTL driver, this
could also occur in virtualization scenario.

For example, UEFI firmware programs ID_OVERRIDE=GROUNDED to set
a type-c port to host mode and keeps the value to kernel.
If the type-c port is connected a usb host, below errors can be
observed right after usb host mode driver gets probed. The errors
would keep until usb role class driver detects the type-c port
as device mode and notifies usb device mode driver to set both
ID_OVERRIDE and VBUS_OVERRIDE to correct value by XUSB PADCTL
driver.

[  173.765814] usb usb3-port2: Cannot enable. Maybe the USB cable is bad?
[  173.765837] usb usb3-port2: config error

Taking virtualization into account, asserting XUSB PADCTL
reset would break XUSB functions used by other guest OS,
hence only reset VBUS & ID OVERRIDE of the port in
utmi_phy_init.

Fixes: bbf7116 ("phy: tegra: xusb: Add Tegra186 support")
Cc: [email protected]
Change-Id: Ic63058d4d49b4a1f8f9ab313196e20ad131cc591
Signed-off-by: BH Hsieh <[email protected]>
Signed-off-by: Henry Lin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: BH Hsieh

drivers/phy/tegra/xusb-tegra186.c

@@ -928,13 +928,24 @@ static int tegra186_utmi_phy_init(struct phy *phy)
 	unsigned int index = lane->index;
 	struct device *dev = padctl->dev;
 	int err;
+	u32 reg;
 
 	port = tegra_xusb_find_usb2_port(padctl, index);
 	if (!port) {
 		dev_err(dev, "no port found for USB2 lane %u\n", index);
 		return -ENODEV;
 	}
 
+	if (port->mode == USB_DR_MODE_OTG ||
+	    port->mode == USB_DR_MODE_PERIPHERAL) {
+		/* reset VBUS&ID OVERRIDE */
+		reg = padctl_readl(padctl, USB2_VBUS_ID);
+		reg &= ~VBUS_OVERRIDE;
+		reg &= ~ID_OVERRIDE(~0);
+		reg |= ID_OVERRIDE_FLOATING;
+		padctl_writel(padctl, reg, USB2_VBUS_ID);
+	}
+
 	if (port->supply && port->mode == USB_DR_MODE_HOST) {
 		err = regulator_enable(port->supply);
 		if (err) {