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 <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index f0fc3a0..b7452c5 100644 (file)
--- 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);