Messages in this thread | | | Date | Tue, 20 Aug 2013 10:53:35 -0600 | From | Stephen Warren <> | Subject | Re: [PATCH 1/2] extcon: extcon-dra7xx: Add extcon driver for USB ID detection |
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On 08/20/2013 12:55 AM, George Cherian wrote: > Hi Stephen, > > Thanks for your review. > > On 8/20/2013 1:01 AM, Stephen Warren wrote: > >> On 08/16/2013 04:13 AM, George Cherian wrote: >>> Adding extcon driver for USB ID detection to dynamically >>> configure USB Host/Peripheral mode. >>> diff --git >>> a/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt >>> b/Documentation/devicetree/bindings/extcon/extcon-dra7xx.txt >>> +EXTCON FOR DRA7xx >>> + >>> +Required Properties: >> Please at lest explain what a DRA7xxx is, and the purpose of the HW >> module this binding describes. > > DRA7xx is the SoC name and the USB VID detection is implemented via gpio's > Basically it does only ID detection via GPIO and there is no VBUS > detection in h/w.
If there's no SoC-specific HW, then the binding has nothing to do with the SoC; it's entirely generic.
I think instead, you need to define a generic "gpio-usb-vid" binding instead.
Otherwise, ever SoC that doesn't have explicit USB VID detection HW is going to re-invent the exact same binding, with pointless differences, rather than using a single generic binding.
>>> + - compatible : Should be "ti,dra7xx-usb" >> >> If this is a USB VID detector rather than a full USB host controller, >> then "usb" in the binding is a bit over-reaching. Perhaps "-usb-vid" or >> "-usb-vid-detector" would be more accurate. > > This will be renamed to dra7xx-extcon.
So no, that rename doesn't sound correct.
>>> + - gpios : phandle to ID pin and interrupt gpio. >> >> Why does the interrupt line need to be included in a list of GPIOs? > > ID pins are connected to pcf8575, and the pcf8575's interrupt line is > inturn connected to > gpio bank6 pin 11, we use this gpio interrupt to detect the ID pin change.
In that case, the PCF8575 node needs to be a GPIO controller and an IRQ controller, as does the driver for the PCF8575. This binding should have a single entry in the gpios property, and the driver can call gpio_to_irq() on that so it knows which IRQ to request.
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