Re: [PATCH v2] gpiolib: return 0 or 1 in gpiod_get_value*() functions

From: Linus Walleij
Date: Thu Dec 10 2015 - 11:54:08 EST


On Mon, Nov 30, 2015 at 6:30 PM, Jose Diaz de Grenu de Pedro
<Jose.DiazdeGrenudePedro@xxxxxxxx> wrote:

> Commit 79a9becda894 moved the awareness of active low state
> into the gpiod_get_value*() functions, but it only inverts the
> GPIO's raw value when it is active low. If the GPIO is active
> high, the gpiod_get_value*() functions return the raw value of
> the register, which can be any positive value.

No, because:

static int _gpiod_get_raw_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
int value;

chip = desc->chip;
offset = gpio_chip_hwgpio(desc);
value = chip->get ? chip->get(chip, offset) : -EIO;
value = value < 0 ? value : !!value;
trace_gpio_value(desc_to_gpio(desc), 1, value);
return value;
}

This returns a negative error code or the value clamped to [0,1]

Yours,
Linus Walleij
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