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| Started by | Jose Diaz de Grenu de Pedro <Jose.DiazdeGrenudePedro@digi.com> |
|---|---|
| First post | 2015-11-30 18:40 +0100 |
| Last post | 2015-12-10 18:00 +0100 |
| Articles | 3 — 3 participants |
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[PATCH v2] gpiolib: return 0 or 1 in gpiod_get_value*() functions Jose Diaz de Grenu de Pedro <Jose.DiazdeGrenudePedro@digi.com> - 2015-11-30 18:40 +0100
Re: [PATCH v2] gpiolib: return 0 or 1 in gpiod_get_value*() functions Bjorn Andersson <bjorn@kryo.se> - 2015-11-30 21:10 +0100
Re: [PATCH v2] gpiolib: return 0 or 1 in gpiod_get_value*() functions Linus Walleij <linus.walleij@linaro.org> - 2015-12-10 18:00 +0100
| From | Jose Diaz de Grenu de Pedro <Jose.DiazdeGrenudePedro@digi.com> |
|---|---|
| Date | 2015-11-30 18:40 +0100 |
| Subject | [PATCH v2] gpiolib: return 0 or 1 in gpiod_get_value*() functions |
| Message-ID | <qAAAF-6D4-7@gated-at.bofh.it> |
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); @@ -2224,9 +2224,9 @@ int gpiod_get_value_cansleep(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_cansleep); -- 2.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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| From | Bjorn Andersson <bjorn@kryo.se> |
|---|---|
| Date | 2015-11-30 21:10 +0100 |
| Message-ID | <qACVQ-8dD-21@gated-at.bofh.it> |
| In reply to | #1280136 |
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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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| From | Linus Walleij <linus.walleij@linaro.org> |
|---|---|
| Date | 2015-12-10 18:00 +0100 |
| Message-ID | <qEcJr-k8-1@gated-at.bofh.it> |
| In reply to | #1280136 |
On Mon, Nov 30, 2015 at 6:30 PM, 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.
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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