From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751170AbbD3IEe (ORCPT ); Thu, 30 Apr 2015 04:04:34 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:58015 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750808AbbD3IEM (ORCPT ); Thu, 30 Apr 2015 04:04:12 -0400 Message-ID: <5541E1F0.6080503@ti.com> Date: Thu, 30 Apr 2015 11:04:00 +0300 From: Roger Quadros User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Chanwoo Choi CC: Peter Chen , Robert Baldyga , "Ivan T. Ivanov" , "Balbi, Felipe" , "ABRAHAM, KISHON VIJAY" , , , , , Subject: Re: [PATCH v3 2/4] extcon: usb-gpio: add support for VBUS detection References: <552CEC97.1050205@samsung.com> <552CEE42.1050907@ti.com> <552CFA1E.5070400@samsung.com> <20150415032734.GA29095@shlinux2> <552E1862.6090709@ti.com> <552E2EBF.5090906@samsung.com> <20150416015922.GB22269@shlinux2> <552F5E17.5020902@samsung.com> <1429168424.26621.1.camel@mm-sol.com> <552F6BE3.5080604@samsung.com> <20150416080107.GC1709@shlinux2> <552F724A.1050500@samsung.com> <5541DAA0.7030200@ti.com> <5541DFEA.8060109@samsung.com> In-Reply-To: <5541DFEA.8060109@samsung.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/04/15 10:55, Chanwoo Choi wrote: > On 04/30/2015 04:32 PM, Roger Quadros wrote: >> 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, >> > > Hi Roger, > >> Do we have an agreement on a common solution then? > > Yes. > >> IMO the above mentioned 4 notifier events should meet all our USB needs. > > I'll support usb notifier chain which includes 4 notifier events. Great, then Robert can base his patches on that. Thanks. cheers, -roger