Hi Sergei,
On 2015년 12월 11일 08:07, Sergei Shtylyov wrote:
> 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.
s/thru/through ?
> 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"...
This patch description includes the double space between words. Also, I think
you need to write the patch description again for formal style.
This patch adds the specific 'enable-gpio' pin to express the SHDN#pin for MAX3355E.
I think it is not regular and standard case because maybe USB specification
don't include the SHDN#pin information. I think it not appropriate way.
Instead, you better to make the MAX3355 extcon driver to support this case.
Thanks,
Chanwoo
>
> 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 linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
>
--
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
