From: Roger Quadros <rogerq@ti.com>
To: Chanwoo Choi <cw00.choi@samsung.com>,
Peter Chen <peter.chen@freescale.com>,
Robert Baldyga <r.baldyga@samsung.com>
Cc: "Ivan T. Ivanov" <iivanov@mm-sol.com>,
"Balbi, Felipe" <balbi@ti.com>,
"ABRAHAM, KISHON VIJAY" <kishon@ti.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, 30 Apr 2015 10:32:48 +0300 [thread overview]
Message-ID: <5541DAA0.7030200@ti.com> (raw)
In-Reply-To: <552F724A.1050500@samsung.com>
On 16/04/15 11:26, Chanwoo Choi wrote:
> On 04/16/2015 05:01 PM, Peter Chen wrote:
>> 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.
>>
>
> OK. I understand.
>
>
Chanwoo, Robert,
Do we have an agreement on a common solution then?
IMO the above mentioned 4 notifier events should meet all our USB needs.
cheers,
-roger
next prev parent reply other threads:[~2015-04-30 7:33 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
2015-04-16 8:26 ` Chanwoo Choi
2015-04-30 7:32 ` Roger Quadros [this message]
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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