On 21 August 2018 at 18:09, Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> On Tue, Aug 21, 2018 at 8:56 AM Loic Poulain <loic.poulain@xxxxxxxxxx> wrote:
>>
>> The Dragonboard-410c is able to act either as USB Host or Device.
>> The role can be determined at runtime via the USB_HS_ID pin which is
>> derived from the micro-usb port VBUS pin.
>>
>> In Host role, SoC USB D+/D- are routed to the onboard USB 2.0 HUB.
>> In Device role, SoC USB D+/D- are routed to the USB 2.0 micro B port.
>> Routing is selected via USB_SW_SEL_PM gpio.
>>
>> In device role USB HUB can be held in reset.
>>
>> Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
>> ---
>
>> @@ -512,7 +513,7 @@
>>
>> usb_id: usb-id {
>> compatible = "linux,extcon-usb-gpio";
>> - vbus-gpio = <&msmgpio 121 GPIO_ACTIVE_HIGH>;
>> + id-gpio = <&msmgpio 121 GPIO_ACTIVE_HIGH>;
>
> The GPIO has magically changed from being connected to Vbus to ID? The
> extcon binding is crap anyways...
Although the pin is derived from VBUS, it is really used as an ID pin (USB_HS_ID
on DB410C schematics [1]), so that DB410C switches to device role when a cable
is inserted to the micro B port.
> Ideally, it would be nice if this was moved to the usb connector binding.
Good suggestion, If you agree, I'll address that in a different patchset.
Regards,
Loic
[1] https://www.96boards.org/documentation/consumer/dragonboard/dragonboard410c/hardware-docs/
