linux-stable/drivers/gpio/gpiolib-legacy.c
Laurent Pinchart 923b93e451 gpiolib: Split GPIO flags parsing and GPIO configuration
When requesting a GPIO through the legacy or the gpiod_* API the
gpiochip request operation is first called and then the GPIO flags are
parsed and the GPIO is configured. This prevents the gpiochip from
rejecting the request if the flags are not supported by the device.

To fix this split the parse-and-configure operation in two and parse
flags before requesting the GPIO.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-16 22:46:46 +02:00

112 lines
2.4 KiB
C

#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio.h>
#include "gpiolib.h"
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);
/* Compatibility: assume unavailable "valid" GPIOs will appear later */
if (!desc && gpio_is_valid(gpio))
return -EPROBE_DEFER;
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);
err = gpiod_request(desc, label);
if (err)
return err;
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)
{
struct gpio_desc *desc = gpio_to_desc(gpio);
/* Compatibility: assume unavailable "valid" GPIOs will appear later */
if (!desc && gpio_is_valid(gpio))
return -EPROBE_DEFER;
return gpiod_request(desc, 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);