Sometimes there's a real OTG chip behind the USB ID signal mapped to a GPIO pin: in my case it's Maxim Integrated MAX3355E which integrates Vbus charge pump and comparators and passes thru the ID signal from an OTG connector. This chip also has the SHDN# pin which should be driven high for the normal operation and low to save power; it is connected to a GPIO pin as well on, hence we'll have to teach the driver to parse the new optional device tree property, "enable-gpio"... Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> --- The patch is against the 'extcon-next' branch of the 'extcon.git' repo. Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt | 3 +++ drivers/extcon/extcon-usb-gpio.c | 5 +++++ 2 files changed, 8 insertions(+) Index: extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt =================================================================== --- extcon.orig/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt +++ extcon/Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt @@ -7,6 +7,9 @@ Required properties: - compatible: Should be "linux,extcon-usb-gpio" - id-gpio: gpio for USB ID pin. See gpio binding. +Optional properties: +- enable-gpio: gpio for the enable pin. See gpio binding. + Example: Examples of extcon-usb-gpio node in dra7-evm.dts as listed below: extcon_usb1 { compatible = "linux,extcon-usb-gpio"; Index: extcon/drivers/extcon/extcon-usb-gpio.c =================================================================== --- extcon.orig/drivers/extcon/extcon-usb-gpio.c +++ extcon/drivers/extcon/extcon-usb-gpio.c @@ -33,6 +33,7 @@ struct usb_extcon_info { struct device *dev; struct extcon_dev *edev; + struct gpio_desc *enable_gpiod; struct gpio_desc *id_gpiod; int id_irq; @@ -99,6 +100,8 @@ static int usb_extcon_probe(struct platf return -ENOMEM; info->dev = dev; + info->enable_gpiod = devm_gpiod_get_optional(&pdev->dev, "enable", + GPIOD_OUT_HIGH); info->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN); if (IS_ERR(info->id_gpiod)) { dev_err(dev, "failed to get ID GPIO\n"); @@ -155,6 +158,8 @@ static int usb_extcon_remove(struct plat cancel_delayed_work_sync(&info->wq_detcable); + gpiod_set_value_cansleep(info->enable_gpiod, 0); + return 0; } -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html