usb: phy: phy-gpio-vbus-usb: Add device tree probing

Make it possible to probe the GPIO VBUS detection driver
from the device tree compatible for GPIO USB B connectors.

Since this driver is using the "gpio-usb-b-connector"
compatible, it is important to discern it from the role
switch connector driver (which does not provide a phy),
so we add some Kconfig text and depend on !USB_CONN_GPIO.

Cc: Rob Herring <robh@kernel.org>
Cc: Prashant Malani <pmalani@chromium.org>
Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221106230506.1646101-1-linus.walleij@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/phy/Kconfig

@@ -93,12 +93,16 @@ config USB_GPIO_VBUS
 	tristate "GPIO based peripheral-only VBUS sensing 'transceiver'"
 	depends on GPIOLIB || COMPILE_TEST
 	depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
+	depends on !USB_CONN_GPIO
 	select USB_PHY
 	help
 	  Provides simple GPIO VBUS sensing for controllers with an
 	  internal transceiver via the usb_phy interface, and
 	  optionally control of a D+ pullup GPIO as well as a VBUS
-	  current limit regulator.
+	  current limit regulator. This driver is for devices that do
+	  NOT support role switch. OTG devices that can do role switch
+	  (master/peripheral) shall use the USB based connection
+	  detection driver USB_CONN_GPIO.
 
 config OMAP_OTG
 	tristate "OMAP USB OTG controller driver"

drivers/usb/phy/phy-gpio-vbus-usb.c

@@ -366,12 +366,24 @@ static const struct dev_pm_ops gpio_vbus_dev_pm_ops = {
 
 MODULE_ALIAS("platform:gpio-vbus");
 
+/*
+ * NOTE: this driver matches against "gpio-usb-b-connector" for
+ * devices that do NOT support role switch.
+ */
+static const struct of_device_id gpio_vbus_of_match[] = {
+	{
+		.compatible = "gpio-usb-b-connector",
+	},
+	{},
+};
+
 static struct platform_driver gpio_vbus_driver = {
 	.driver = {
 		.name  = "gpio-vbus",
 #ifdef CONFIG_PM
 		.pm = &gpio_vbus_dev_pm_ops,
 #endif
+		.of_match_table = gpio_vbus_of_match,
 	},
 	.probe		= gpio_vbus_probe,
 	.remove		= gpio_vbus_remove,