Messages in this thread | | | Date | Mon, 30 Nov 2015 12:05:49 -0800 | Subject | Re: [PATCH v2] gpiolib: return 0 or 1 in gpiod_get_value*() functions | From | Bjorn Andersson <> |
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On Mon, Nov 30, 2015 at 9:30 AM, Jose Diaz de Grenu de Pedro <Jose.DiazdeGrenudePedro@digi.com> 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. > > This patch does a double inversion when the GPIO is active high > to make sure either 0 or 1 is returned by these functions. > > Signed-off-by: Jose Diaz de Grenu de Pedro <Jose.DiazdeGrenudePedro@digi.com> > Signed-off-by: Hector Palacios <hector.palacios@digi.com> > --- > change in v2: > - add missing semicolon > --- > drivers/gpio/gpiolib.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index 50c4922fe53a..bd96f0457ba8 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -1981,9 +1981,9 @@ int gpiod_get_value(const struct gpio_desc *desc) > > value = _gpiod_get_raw_value(desc); > if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) > - value = !value; > - > - return value; > + return !value; > + else > + return !!value; > } > EXPORT_SYMBOL_GPL(gpiod_get_value);
On linux-next (at least) _gpiod_get_raw_value() returns the following value:
value = value < 0 ? value : !!value;
So this should already be negative errno, 0 or 1.
Regards, Bjorn
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