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gpio: clamp values on gpio[d]_direction_output()

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I saw weird values != [0,1] being passed down to drivers
in their .set_direction_output() callbacks. Go over the
gpiolib and make sure to hammer it to [0,1] before hitting
the driver to avoid undesired side effects.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Linus Walleij 2016-11-13 23:02:44 +01:00
parent 24b35ed9a8
commit ad17731d7b
1 changed files with 8 additions and 5 deletions
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13
drivers/gpio/gpiolib.c
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@ -2150,6 +2150,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input);
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
struct gpio_chip *gc = desc->gdev->chip;
int val = !!value;
int ret;
/* GPIOs used for IRQs shall not be set as output */
@ -2169,7 +2170,7 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
goto set_output_value;
}
/* Emulate open drain by not actively driving the line high */
if (value)
if (val)
return gpiod_direction_input(desc);
}
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
@ -2180,7 +2181,7 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
goto set_output_value;
}
/* Emulate open source by not actively driving the line low */
if (!value)
if (!val)
return gpiod_direction_input(desc);
} else {
/* Make sure to disable open drain/source hardware, if any */
@ -2198,10 +2199,10 @@ set_output_value:
return -EIO;
}
ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_value(desc_to_gpio(desc), 0, value);
trace_gpio_value(desc_to_gpio(desc), 0, val);
trace_gpio_direction(desc_to_gpio(desc), 0, ret);
return ret;
}
@ -2241,6 +2242,8 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
VALIDATE_DESC(desc);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
else
value = !!value;
return _gpiod_direction_output_raw(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
@ -3094,7 +3097,7 @@ static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
/* Process flags */
if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
status = gpiod_direction_output(desc,
dflags & GPIOD_FLAGS_BIT_DIR_VAL);
!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
else
status = gpiod_direction_input(desc);