From ad17731d7bd1c379f83d4bde844169588441266f Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sun, 13 Nov 2016 23:02:44 +0100 Subject: [PATCH] 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: Linus Walleij --- drivers/gpio/gpiolib.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index f0fc3a0d37c8..b7452c5223be 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -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); -- 2.20.1