Commit def63433 authored by Alexandre Courbot's avatar Alexandre Courbot Committed by Grant Likely

gpiolib: use const parameters when possible

Constify descriptor parameter of gpiod_* functions for those that
should obviously not modify it. This includes value or direction get,
cansleep, and IRQ number query.
Signed-off-by: default avatarAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent bcabdef1
......@@ -88,13 +88,14 @@ static int gpiod_request(struct gpio_desc *desc, const char *label);
static void gpiod_free(struct gpio_desc *desc);
static int gpiod_direction_input(struct gpio_desc *desc);
static int gpiod_direction_output(struct gpio_desc *desc, int value);
static int gpiod_get_direction(const struct gpio_desc *desc);
static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce);
static int gpiod_get_value_cansleep(struct gpio_desc *desc);
static int gpiod_get_value_cansleep(const struct gpio_desc *desc);
static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value);
static int gpiod_get_value(struct gpio_desc *desc);
static int gpiod_get_value(const struct gpio_desc *desc);
static void gpiod_set_value(struct gpio_desc *desc, int value);
static int gpiod_cansleep(struct gpio_desc *desc);
static int gpiod_to_irq(struct gpio_desc *desc);
static int gpiod_cansleep(const struct gpio_desc *desc);
static int gpiod_to_irq(const struct gpio_desc *desc);
static int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
static int gpiod_export_link(struct device *dev, const char *name,
struct gpio_desc *desc);
......@@ -172,7 +173,7 @@ static int gpio_ensure_requested(struct gpio_desc *desc)
}
/* caller holds gpio_lock *OR* gpio is marked as requested */
static struct gpio_chip *gpiod_to_chip(struct gpio_desc *desc)
static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
return desc ? desc->chip : NULL;
}
......@@ -207,7 +208,7 @@ static int gpiochip_find_base(int ngpio)
}
/* caller ensures gpio is valid and requested, chip->get_direction may sleep */
static int gpiod_get_direction(struct gpio_desc *desc)
static int gpiod_get_direction(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
unsigned offset;
......@@ -223,11 +224,13 @@ static int gpiod_get_direction(struct gpio_desc *desc)
if (status > 0) {
/* GPIOF_DIR_IN, or other positive */
status = 1;
clear_bit(FLAG_IS_OUT, &desc->flags);
/* 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);
}
if (status == 0) {
/* GPIOF_DIR_OUT */
set_bit(FLAG_IS_OUT, &desc->flags);
set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
}
return status;
}
......@@ -263,7 +266,7 @@ static DEFINE_MUTEX(sysfs_lock);
static ssize_t gpio_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_desc *desc = dev_get_drvdata(dev);
const struct gpio_desc *desc = dev_get_drvdata(dev);
ssize_t status;
mutex_lock(&sysfs_lock);
......@@ -1830,7 +1833,7 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce);
* It returns the zero or nonzero value provided by the associated
* gpio_chip.get() method; or zero if no such method is provided.
*/
static int gpiod_get_value(struct gpio_desc *desc)
static int gpiod_get_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
......@@ -1948,7 +1951,7 @@ EXPORT_SYMBOL_GPL(__gpio_set_value);
* This is used directly or indirectly to implement gpio_cansleep(). It
* returns nonzero if access reading or writing the GPIO value can sleep.
*/
static int gpiod_cansleep(struct gpio_desc *desc)
static int gpiod_cansleep(const struct gpio_desc *desc)
{
if (!desc)
return 0;
......@@ -1971,7 +1974,7 @@ EXPORT_SYMBOL_GPL(__gpio_cansleep);
* It returns the number of the IRQ signaled by this (input) GPIO,
* or a negative errno.
*/
static int gpiod_to_irq(struct gpio_desc *desc)
static int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
......@@ -1994,7 +1997,7 @@ EXPORT_SYMBOL_GPL(__gpio_to_irq);
* Common examples include ones connected to I2C or SPI chips.
*/
static int gpiod_get_value_cansleep(struct gpio_desc *desc)
static int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
......
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