Re: [PATCH] pio: add arch specific gpio_is_valid() function

From: avictor.za@xxxxxxxxx
Date: Tue Sep 07 2010 - 15:13:17 EST


hi,

> NAK still.  You're trying to abuse gpio_is_valid(),
> which I see no need to support.
>
> In terms of GPIO framework architecture, zero is
> the first GPIO in all cases, and is always
> a valid GPIO number, even if it's not
> requestable/swritable/readable on a given board.
>
> Whether it's usable on a given platform depends
> on whether a GPIO controller is registered which
> claims numbers 0..N ... (assuming gpiolib in use).

How should the following be done in a driver then?

if (gpio_is_valid(device->output_pin)) {
if (gpio_request(device->output_pin, "driverX") != 0)
goto error_handling;

/* continue with gpio setup */
}
else {
/* there is no vcc_pin, so don't do any gpio setup */
}

....

if (gpio_is_valid(device->output_pin)) {
/* set value high */
}


Regards,
Andrew Victor
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