Hi Robert, On 03/20/2015 04:25 PM, Robert Baldyga wrote: > Hi Chanwoo, > > On 03/19/2015 09:50 PM, Chanwoo Choi wrote: >> Hi Roger, >> >> On Thu, Mar 19, 2015 at 11:45 PM, Roger Quadros <rogerq@xxxxxx> wrote: >>> On 19/03/15 14:19, George Cherian wrote: >>>> Hi Robert, >>>> >>>> +Roger >>>> On Thu, Mar 19, 2015 at 5:37 PM, Robert Baldyga <r.baldyga@xxxxxxxxxxx> wrote: >>>>> Hi George, >>>>> >>>>> On 03/19/2015 09:50 AM, George Cherian wrote: >>>>>> Hi Robert, >>>>>> >>>>>> This looks like a extcon driver based on gpio for USB. >>>>>> >>>>>> Roger posted a generic one a while back. >>>>>> https://lkml.org/lkml/2015/2/2/187 >>>>>> >>>>>> Doesn't this serve the purpose rather than adding this driver? >>>>> >>>>> Roger's driver doesn't support VBUS state detection so it cannot handle >>>> I feel Roger's driver could be extended for supporting VBUS. >>>> Also I think Roger's driver is about to get merged. >>>> Probably, Roger or Chanwoo can better tell that >>> >>> It is already queued for 4.1 and is available in linux-next. >>> >>>> >>>>> situation when USB cable is unpluged. In addition some of Odroid boards >>>>> has only VBUS detection (without ID pin), so this driver cannot handle >>>>> them at all. >>> >>> why not? >>> >>> x15-beagleboard also gets VBUS event over GPIO and I was planning to extent it >>> to support VBUS detection. >> >> Sounds good to me to extent extcon-usb-gpio.c. >> I'd like to hold only one extcon driver to support both USB and >> USB-HOST with gpio . >> >> There are one more extcon-gpio driver in mailing list as following: >> - extcon-usb-gpio.c (will be merged to Linux 4.1) >> - extcon-odroid-usbotg.c >> - extcon-otg_gpio.c [1] >> [1] https://lkml.org/lkml/2015/2/19/411 >> >> The each extcon gpio driver support both USB/USB-HOST cable by using >> different way, >> Because some board which detect USB/USB-HOST by gpio have a little >> different pin composition > > These differences are small. In general we have three cases: > > 1. We have both VBUS and ID pin detection - we can detect USB, USB-HOST > and cable disconnection. > > 2. We have only VBUS detection - we can detect USB and cable disconnection. > > 3. We have ID pin only - we can distinguish between USB and USB-HOST but > without ability to detect cable disconnection. > >> >> I think only one extcon driver can support all cases with optional properties. > > So my driver in current form is ready for that. Only thing it would need > to change is to make VBUS detection an option (for now is mandatory > because all of supported Odroid boards have it). Then boards with VBUS > detection only or ID pin detection only will be handled also. I can also > change name of the driver to more generic. I'm going to prepare V2 on my > patches today. Could you implement this feature on extcon-usb-gpio.c to support various pin composition? because extcon-usb-gpio.c was already implemented by Roger. If you implement other extcon driver to detect USB/USB-HOST cable by using gpio, there will be similar two extcon gpio driver for USB cable. And, As Roger comment, he have the plan to extend the extcon-usb-gpio.c. So, If you will implement some feature for extcon driver with gpio, I'd like you to share your plan this thread to remove duplicat work. Thanks, Chanwoo Choi > > Thanks, > Robert Baldyga > >> >> Roger, >> I'd like you to share your plan to extent the extcon-usb-gpio.c for >> removing duplicate work. >> >> [snip] >> >> Thanks, >> Chanwoo Choi >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-usb" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
