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linux-next/include/linux/gpio.h
Johan Hovold 166a85e442 gpio: remove gpiod_sysfs_set_active_low
Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.

Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.

It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.

Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.

There are no in-kernel users of this interface.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:53 +02:00

278 lines
5.6 KiB
C

#ifndef __LINUX_GPIO_H
#define __LINUX_GPIO_H
#include <linux/errno.h>
/* see Documentation/gpio/gpio-legacy.txt */
/* make these flag values available regardless of GPIO kconfig options */
#define GPIOF_DIR_OUT (0 << 0)
#define GPIOF_DIR_IN (1 << 0)
#define GPIOF_INIT_LOW (0 << 1)
#define GPIOF_INIT_HIGH (1 << 1)
#define GPIOF_IN (GPIOF_DIR_IN)
#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
/* Gpio pin is active-low */
#define GPIOF_ACTIVE_LOW (1 << 2)
/* Gpio pin is open drain */
#define GPIOF_OPEN_DRAIN (1 << 3)
/* Gpio pin is open source */
#define GPIOF_OPEN_SOURCE (1 << 4)
#define GPIOF_EXPORT (1 << 5)
#define GPIOF_EXPORT_CHANGEABLE (1 << 6)
#define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT)
#define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
/**
* struct gpio - a structure describing a GPIO with configuration
* @gpio: the GPIO number
* @flags: GPIO configuration as specified by GPIOF_*
* @label: a literal description string of this GPIO
*/
struct gpio {
unsigned gpio;
unsigned long flags;
const char *label;
};
#ifdef CONFIG_GPIOLIB
#ifdef CONFIG_ARCH_HAVE_CUSTOM_GPIO_H
#include <asm/gpio.h>
#else
#include <asm-generic/gpio.h>
static inline int gpio_get_value(unsigned int gpio)
{
return __gpio_get_value(gpio);
}
static inline void gpio_set_value(unsigned int gpio, int value)
{
__gpio_set_value(gpio, value);
}
static inline int gpio_cansleep(unsigned int gpio)
{
return __gpio_cansleep(gpio);
}
static inline int gpio_to_irq(unsigned int gpio)
{
return __gpio_to_irq(gpio);
}
static inline int irq_to_gpio(unsigned int irq)
{
return -EINVAL;
}
#endif /* ! CONFIG_ARCH_HAVE_CUSTOM_GPIO_H */
/* CONFIG_GPIOLIB: bindings for managed devices that want to request gpios */
struct device;
int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
int devm_gpio_request_one(struct device *dev, unsigned gpio,
unsigned long flags, const char *label);
void devm_gpio_free(struct device *dev, unsigned int gpio);
#else /* ! CONFIG_GPIOLIB */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bug.h>
#include <linux/pinctrl/pinctrl.h>
struct device;
struct gpio_chip;
static inline bool gpio_is_valid(int number)
{
return false;
}
static inline int gpio_request(unsigned gpio, const char *label)
{
return -ENOSYS;
}
static inline int gpio_request_one(unsigned gpio,
unsigned long flags, const char *label)
{
return -ENOSYS;
}
static inline int gpio_request_array(const struct gpio *array, size_t num)
{
return -ENOSYS;
}
static inline void gpio_free(unsigned gpio)
{
might_sleep();
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline void gpio_free_array(const struct gpio *array, size_t num)
{
might_sleep();
/* GPIO can never have been requested */
WARN_ON(1);
}
static inline int gpio_direction_input(unsigned gpio)
{
return -ENOSYS;
}
static inline int gpio_direction_output(unsigned gpio, int value)
{
return -ENOSYS;
}
static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
{
return -ENOSYS;
}
static inline int gpio_get_value(unsigned gpio)
{
/* GPIO can never have been requested or set as {in,out}put */
WARN_ON(1);
return 0;
}
static inline void gpio_set_value(unsigned gpio, int value)
{
/* GPIO can never have been requested or set as output */
WARN_ON(1);
}
static inline int gpio_cansleep(unsigned gpio)
{
/* GPIO can never have been requested or set as {in,out}put */
WARN_ON(1);
return 0;
}
static inline int gpio_get_value_cansleep(unsigned gpio)
{
/* GPIO can never have been requested or set as {in,out}put */
WARN_ON(1);
return 0;
}
static inline void gpio_set_value_cansleep(unsigned gpio, int value)
{
/* GPIO can never have been requested or set as output */
WARN_ON(1);
}
static inline int gpio_export(unsigned gpio, bool direction_may_change)
{
/* GPIO can never have been requested or set as {in,out}put */
WARN_ON(1);
return -EINVAL;
}
static inline int gpio_export_link(struct device *dev, const char *name,
unsigned gpio)
{
/* GPIO can never have been exported */
WARN_ON(1);
return -EINVAL;
}
static inline void gpio_unexport(unsigned gpio)
{
/* GPIO can never have been exported */
WARN_ON(1);
}
static inline int gpio_to_irq(unsigned gpio)
{
/* GPIO can never have been requested or set as input */
WARN_ON(1);
return -EINVAL;
}
static inline int gpiochip_lock_as_irq(struct gpio_chip *chip,
unsigned int offset)
{
WARN_ON(1);
return -EINVAL;
}
static inline void gpiochip_unlock_as_irq(struct gpio_chip *chip,
unsigned int offset)
{
WARN_ON(1);
}
static inline int irq_to_gpio(unsigned irq)
{
/* irq can never have been returned from gpio_to_irq() */
WARN_ON(1);
return -EINVAL;
}
static inline int
gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
unsigned int npins)
{
WARN_ON(1);
return -EINVAL;
}
static inline int
gpiochip_add_pingroup_range(struct gpio_chip *chip,
struct pinctrl_dev *pctldev,
unsigned int gpio_offset, const char *pin_group)
{
WARN_ON(1);
return -EINVAL;
}
static inline void
gpiochip_remove_pin_ranges(struct gpio_chip *chip)
{
WARN_ON(1);
}
static inline int devm_gpio_request(struct device *dev, unsigned gpio,
const char *label)
{
WARN_ON(1);
return -EINVAL;
}
static inline int devm_gpio_request_one(struct device *dev, unsigned gpio,
unsigned long flags, const char *label)
{
WARN_ON(1);
return -EINVAL;
}
static inline void devm_gpio_free(struct device *dev, unsigned int gpio)
{
WARN_ON(1);
}
#endif /* ! CONFIG_GPIOLIB */
#endif /* __LINUX_GPIO_H */