Commit 8e53b0f1 authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Linus Walleij

gpio: remove const modifier from gpiod_get_direction()

Although gpiod_get_direction() can be considered side-effect free for
consumers, its internals involve setting or clearing bits in the
affected GPIO descriptor, for which we need to force-cast the const
descriptor variable to non-const. This could lead to incorrect behavior
if the compiler decides to optimize here, so remove this const
attribute. The intent is to make gpiod_get_direction() private anyway,
so it does not really matter.
Reported-by: default avatarUwe Kleine-König <>
Signed-off-by: default avatarAlexandre Courbot <>
Acked-by: default avatarUwe Kleine-König <>
Signed-off-by: Linus Walleij's avatarLinus Walleij <>
parent 14e85c0e
......@@ -41,7 +41,7 @@ static DEFINE_MUTEX(sysfs_lock);
static ssize_t gpio_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
const struct gpio_desc *desc = dev_get_drvdata(dev);
struct gpio_desc *desc = dev_get_drvdata(dev);
ssize_t status;
......@@ -148,7 +148,7 @@ static int gpiochip_find_base(int ngpio)
* This function may sleep if gpiod_cansleep() is true.
int gpiod_get_direction(const struct gpio_desc *desc)
int gpiod_get_direction(struct gpio_desc *desc)
struct gpio_chip *chip;
unsigned offset;
......@@ -164,13 +164,11 @@ int gpiod_get_direction(const struct gpio_desc *desc)
if (status > 0) {
/* GPIOF_DIR_IN, or other positive */
status = 1;
/* FLAG_IS_OUT is just a cache of the result of get_direction(),
* so it does not affect constness per se */
clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
clear_bit(FLAG_IS_OUT, &desc->flags);
if (status == 0) {
set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
set_bit(FLAG_IS_OUT, &desc->flags);
return status;
......@@ -66,7 +66,7 @@ __devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
unsigned int index, enum gpiod_flags flags);
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
int gpiod_get_direction(const struct gpio_desc *desc);
int gpiod_get_direction(struct gpio_desc *desc);
int gpiod_direction_input(struct gpio_desc *desc);
int gpiod_direction_output(struct gpio_desc *desc, int value);
int gpiod_direction_output_raw(struct gpio_desc *desc, int value);
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