Re: [PATCH v3 1/3] extcon: extcon-gpio-usbvid: Generic USB VBUS/ID detection via GPIO

[Stephen Warren <swarren@wwwdotorg.org>]

On 08/29/2013 05:48 AM, George Cherian wrote:
> On 8/29/2013 4:07 PM, Chanwoo Choi wrote:
...
>> I tested various development board based on Samsung Exynos series SoC.
>> Although some gpio of Exynos series SoC set high state(non zero, 1) as
>> default value,
>> this gpio state could mean off state, disconnected or un-powered state
>> according to gpio.
>> Of course, above explanation about specific gpio don't include all gpios.
>> This is meaning that there is possibility.
>
> okay then how about adding a flag for inverted logic too.  something
> like this
> 
> if(of_property_read_bool(np,"inverted_gpio))
>     gpio_usbvid->gpio_inv = 1;
>
> And always check on this before deciding?

Don't do this. GPIO specifiers in DT typically include a "flags" cell
that describes certain GPIO properties. One of those properties is
signal inversion. You can use of_get_named_gpio_flags() to retrieve
those flags.