Re: [PATCH v3 2/4] extcon: usb-gpio: add support for VBUS detection

From: Ivan T. Ivanov
Date: Thu Apr 16 2015 - 03:14:02 EST


On Thu, 2015-04-16 at 16:00 +0900, Chanwoo Choi wrote:
> Hi Peter,
> On 04/16/2015 10:59 AM, Peter Chen wrote:
> >

> > Ok, from USB point, external id/vbus value can't decide
> > which role the controller will be, the controller driver
> > will decide role according to many things, eg, user configurations,
> > id/vbus value, OTG HNP, etc.
> >
> > So, from USB controller/phy driver, it doesn't care which cable is
> > inserted, it cares about id/vbus value. Eg, it can get id/vbus value
> > and it will be notified when the id/vbus value has changed.
> OK, I change the notifier name and add notifier events as following:
> - extcon_{register|unregister}_usb_notifier(struct extcon_dev *edev, struct notifier_block *nb);
> - list of notifier events
> #define EXTCON_USB_ID_L_VBUS_L0 /* ID low and VBUS low */
> #define EXTCON_USB_ID_L_VBUS_H1 /* ID low and VBUS high */
> #define EXTCON_USB_ID_H_VBUS_L2 /* ID high and VBUS low */
> #define EXTCON_USB_ID_H_VBUS_H3 /* ID high and VBUS high */

I am still confused, why we mix ID and VBUS events into one?
Those are two lines and they are not necessarily handled by
the same extcon_dev.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at