From: Linus Walleij <linus.walleij@linaro.org>
Date: Sun, 13 Nov 2016 22:02:44 +0000 (+0100)
Subject: gpio: clamp values on gpio[d]_direction_output()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ad17731d7bd1c379f83d4bde844169588441266f;p=linux-beck.git

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 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);