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

From: Peter Chen
Date: Thu Apr 16 2015 - 04:02:46 EST


On Thu, Apr 16, 2015 at 10:13:44AM +0300, Ivan T. Ivanov wrote:
> Hi,
>
> 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.

Yes, from consumer side, we only need one element per time, eg vbus
or id.

--

Best Regards,
Peter Chen
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