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

drivers/gpio/gpiolib.c

+16 −13
Original line number Diff line number Diff line
@@ -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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