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#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio.h>
#include "gpiolib.h"
/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
* when setting direction, and otherwise illegal. Until board setup code
* and drivers use explicit requests everywhere (which won't happen when
* those calls have no teeth) we can't avoid autorequesting. This nag
* message should motivate switching to explicit requests... so should
* the weaker cleanup after faults, compared to gpio_request().
*
* NOTE: the autorequest mechanism is going away; at this point it's
* only "legal" in the sense that (old) code using it won't break yet,
* but instead only triggers a WARN() stack dump.
*/
static int gpio_ensure_requested(struct gpio_desc *desc)
{
struct gpio_chip *chip = desc->chip;
unsigned long flags;
bool request = false;
int err = 0;
spin_lock_irqsave(&gpio_lock, flags);
if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
"autorequest GPIO-%d\n", desc_to_gpio(desc))) {
if (!try_module_get(chip->owner)) {
gpiod_err(desc, "%s: module can't be gotten\n",
__func__);
clear_bit(FLAG_REQUESTED, &desc->flags);
/* lose */
err = -EIO;
goto end;
}
desc->label = "[auto]";
/* caller must chip->request() w/o spinlock */
if (chip->request)
request = true;
}
end:
spin_unlock_irqrestore(&gpio_lock, flags);
if (request) {
might_sleep_if(chip->can_sleep);
err = chip->request(chip, gpio_chip_hwgpio(desc));
if (err < 0) {
gpiod_dbg(desc, "%s: chip request fail, %d\n",
__func__, err);
spin_lock_irqsave(&gpio_lock, flags);
desc->label = NULL;
clear_bit(FLAG_REQUESTED, &desc->flags);
spin_unlock_irqrestore(&gpio_lock, flags);
}
}
return err;
}
void gpio_free(unsigned gpio)
{
gpiod_free(gpio_to_desc(gpio));
}
EXPORT_SYMBOL_GPL(gpio_free);
/**
* gpio_request_one - request a single GPIO with initial configuration
* @gpio: the GPIO number
* @flags: GPIO configuration as specified by GPIOF_*
* @label: a literal description string of this GPIO
*/
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
{
struct gpio_desc *desc;
int err;
desc = gpio_to_desc(gpio);
err = gpiod_request(desc, label);
if (err)
return err;
if (flags & GPIOF_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (flags & GPIOF_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
if (flags & GPIOF_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (flags & GPIOF_DIR_IN)
err = gpiod_direction_input(desc);
else
err = gpiod_direction_output_raw(desc,
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
if (err)
goto free_gpio;
if (flags & GPIOF_EXPORT) {
err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE);
if (err)
goto free_gpio;
}
return 0;
free_gpio:
gpiod_free(desc);
return err;
}
EXPORT_SYMBOL_GPL(gpio_request_one);
int gpio_request(unsigned gpio, const char *label)
{
return gpiod_request(gpio_to_desc(gpio), label);
}
EXPORT_SYMBOL_GPL(gpio_request);
/**
* gpio_request_array - request multiple GPIOs in a single call
* @array: array of the 'struct gpio'
* @num: how many GPIOs in the array
*/
int gpio_request_array(const struct gpio *array, size_t num)
{
int i, err;
for (i = 0; i < num; i++, array++) {
err = gpio_request_one(array->gpio, array->flags, array->label);
if (err)
goto err_free;
}
return 0;
err_free:
while (i--)
gpio_free((--array)->gpio);
return err;
}
EXPORT_SYMBOL_GPL(gpio_request_array);
/**
* gpio_free_array - release multiple GPIOs in a single call
* @array: array of the 'struct gpio'
* @num: how many GPIOs in the array
*/
void gpio_free_array(const struct gpio *array, size_t num)
{
while (num--)
gpio_free((array++)->gpio);
}
EXPORT_SYMBOL_GPL(gpio_free_array);
int gpio_direction_input(unsigned gpio)
{
struct gpio_desc *desc = gpio_to_desc(gpio);
int err;
if (!desc)
return -EINVAL;
err = gpio_ensure_requested(desc);
if (err < 0)
return err;
return gpiod_direction_input(desc);
}
EXPORT_SYMBOL_GPL(gpio_direction_input);
int gpio_direction_output(unsigned gpio, int value)
{
struct gpio_desc *desc = gpio_to_desc(gpio);
int err;
if (!desc)
return -EINVAL;
err = gpio_ensure_requested(desc);
if (err < 0)
return err;
return gpiod_direction_output_raw(desc, value);
}
EXPORT_SYMBOL_GPL(gpio_direction_output);
int gpio_set_debounce(unsigned gpio, unsigned debounce)
{
struct gpio_desc *desc = gpio_to_desc(gpio);
int err;
if (!desc)
return -EINVAL;
err = gpio_ensure_requested(desc);
if (err < 0)
return err;
return gpiod_set_debounce(desc, debounce);
}
EXPORT_SYMBOL_GPL(gpio_set_debounce);
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