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Commit ad17731d authored by Linus Walleij's avatar Linus Walleij
Browse files

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



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: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 24b35ed9

drivers/gpio/gpiolib.c

+8 −5
Original line number Diff line number Diff line
@@ -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 @@ static int _gpiod_direction_output_raw(struct gpio_desc *desc, int 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);