From: Peter Chen <peter.chen@freescale.com>
To: Chanwoo Choi <cw00.choi@samsung.com>
Cc: "Ivan T. Ivanov" <iivanov@mm-sol.com>,
"Balbi, Felipe" <balbi@ti.com>,
"ABRAHAM, KISHON VIJAY" <kishon@ti.com>,
Roger Quadros <rogerq@ti.com>,
Robert Baldyga <r.baldyga@samsung.com>,
<myungjoo.ham@samsung.com>, <linux-usb@vger.kernel.org>,
<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<m.szyprowski@samsung.com>
Subject: Re: [PATCH v3 2/4] extcon: usb-gpio: add support for VBUS detection
Date: Thu, 16 Apr 2015 16:01:08 +0800 [thread overview]
Message-ID: <20150416080107.GC1709@shlinux2> (raw)
In-Reply-To: <552F6BE3.5080604@samsung.com>
On Thu, Apr 16, 2015 at 04:59:31PM +0900, Chanwoo Choi wrote:
> On 04/16/2015 04:13 PM, 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.
>
> IMO, if some usb driver check both id and vbus pin at the same time,
> the usb driver can know the both id and vbus pin state through only one notifier event.
>
> Also,
> If some usb driver want to know the state of id pin except of vbus state,
> when receiving following events, id pin is low.
> #define EXTCON_USB_ID_L_VBUS_L0
> #define EXTCON_USB_ID_L_VBUS_H1
> when receiving following events, id pin is high.
> #define EXTCON_USB_ID_H_VBUS_L2
> #define EXTCON_USB_ID_H_VBUS_H3
> Also, some usb driver would catch the vbus pin state with same method.
>
> But, it is just my opinion. We may use following notifier events for each pin.
> We need to discuss it.
> #define EXTCON_USB_ID_LOW
> #define EXTCON_USB_ID_HIGH
> #define EXTCON_USB_VBUS_LOW
> #define EXTCON_USB_VBUS_HIGH
>
I agree with above definition.
--
Best Regards,
Peter Chen
next prev parent reply other threads:[~2015-04-16 8:03 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-02 13:13 [PATCH v3 0/4] extcon: usb-gpio: fixes and improvements Robert Baldyga
2015-04-02 13:13 ` [PATCH v3 1/4] extcon: usb-gpio: register extcon device before IRQ registration Robert Baldyga
2015-04-03 0:09 ` Chanwoo Choi
2015-04-02 13:13 ` [PATCH v3 2/4] extcon: usb-gpio: add support for VBUS detection Robert Baldyga
2015-04-02 14:02 ` Roger Quadros
2015-04-09 2:12 ` Chanwoo Choi
2015-04-09 7:57 ` Robert Baldyga
2015-04-09 9:07 ` Chanwoo Choi
2015-04-09 9:24 ` Robert Baldyga
2015-04-09 9:59 ` Roger Quadros
2015-04-09 10:18 ` Robert Baldyga
2015-04-10 7:39 ` Chanwoo Choi
2015-04-10 7:17 ` Chanwoo Choi
2015-04-10 7:45 ` Robert Baldyga
2015-04-10 8:10 ` Chanwoo Choi
2015-04-10 8:46 ` Robert Baldyga
2015-04-10 9:18 ` Chanwoo Choi
2015-04-10 9:42 ` Robert Baldyga
2015-04-14 10:01 ` Roger Quadros
2015-04-14 10:02 ` Roger Quadros
2015-04-14 10:31 ` Chanwoo Choi
2015-04-14 10:38 ` Roger Quadros
2015-04-14 11:29 ` Chanwoo Choi
2015-04-15 3:27 ` Peter Chen
2015-04-15 7:50 ` Roger Quadros
2015-04-15 9:26 ` Chanwoo Choi
2015-04-16 1:59 ` Peter Chen
2015-04-16 7:00 ` Chanwoo Choi
2015-04-16 7:13 ` Ivan T. Ivanov
2015-04-16 7:59 ` Chanwoo Choi
2015-04-16 8:01 ` Peter Chen [this message]
2015-04-16 8:26 ` Chanwoo Choi
2015-04-30 7:32 ` Roger Quadros
2015-04-30 7:55 ` Chanwoo Choi
2015-04-30 8:04 ` Roger Quadros
2015-04-16 7:59 ` Peter Chen
2015-04-16 7:16 ` Roger Quadros
2015-04-02 13:13 ` [PATCH v3 3/4] extcon: usb-gpio: make debounce value configurable in devicetree Robert Baldyga
2015-04-02 13:13 ` [PATCH v3 4/4] Documentation: extcon: usb-gpio: update usb-gpio binding description Robert Baldyga
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