WSL2-Linux-Kernel/include/linux/gpio.h

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5.0 KiB
C
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#ifndef __LINUX_GPIO_H
#define __LINUX_GPIO_H
#include <linux/errno.h>
/* see Documentation/gpio.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 open drain */
#define GPIOF_OPEN_DRAIN (1 << 2)
/* Gpio pin is open source */
#define GPIOF_OPEN_SOURCE (1 << 3)
#define GPIOF_EXPORT (1 << 4)
#define GPIOF_EXPORT_CHANGEABLE (1 << 5)
#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_GENERIC_GPIO
#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 */
#else /* ! CONFIG_GENERIC_GPIO */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/bug.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 devm_gpio_request(struct device *dev, 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 devm_gpio_request_one(struct device *dev, 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 devm_gpio_free(struct device *dev, 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;
}
2010-05-27 01:42:23 +04:00
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);
}
gpio: sysfs interface This adds a simple sysfs interface for GPIOs. /sys/class/gpio /export ... asks the kernel to export a GPIO to userspace /unexport ... to return a GPIO to the kernel /gpioN ... for each exported GPIO #N /value ... always readable, writes fail for input GPIOs /direction ... r/w as: in, out (default low); write high, low /gpiochipN ... for each gpiochip; #N is its first GPIO /base ... (r/o) same as N /label ... (r/o) descriptive, not necessarily unique /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1) GPIOs claimed by kernel code may be exported by its owner using a new gpio_export() call, which should be most useful for driver debugging. Such exports may optionally be done without a "direction" attribute. Userspace may ask to take over a GPIO by writing to a sysfs control file, helping to cope with incomplete board support or other "one-off" requirements that don't merit full kernel support: echo 23 > /sys/class/gpio/export ... will gpio_request(23, "sysfs") and gpio_export(23); use /sys/class/gpio/gpio-23/direction to (re)configure it, when that GPIO can be used as both input and output. echo 23 > /sys/class/gpio/unexport ... will gpio_free(23), when it was exported as above The extra D-space footprint is a few hundred bytes, except for the sysfs resources associated with each exported GPIO. The additional I-space footprint is about two thirds of the current size of gpiolib (!). Since no /dev node creation is involved, no "udev" support is needed. Related changes: * This adds a device pointer to "struct gpio_chip". When GPIO providers initialize that, sysfs gpio class devices become children of that device instead of being "virtual" devices. * The (few) gpio_chip providers which have such a device node have been updated. * Some gpio_chip drivers also needed to update their module "owner" field ... for which missing kerneldoc was added. * Some gpio_chips don't support input GPIOs. Those GPIOs are now flagged appropriately when the chip is registered. Based on previous patches, and discussion both on and off LKML. A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this merges to mainline. [akpm@linux-foundation.org: a few maintenance build fixes] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 12:46:07 +04:00
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 int gpio_sysfs_set_active_low(unsigned gpio, int value)
{
/* GPIO can never have been requested */
WARN_ON(1);
return -EINVAL;
}
gpio: sysfs interface This adds a simple sysfs interface for GPIOs. /sys/class/gpio /export ... asks the kernel to export a GPIO to userspace /unexport ... to return a GPIO to the kernel /gpioN ... for each exported GPIO #N /value ... always readable, writes fail for input GPIOs /direction ... r/w as: in, out (default low); write high, low /gpiochipN ... for each gpiochip; #N is its first GPIO /base ... (r/o) same as N /label ... (r/o) descriptive, not necessarily unique /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1) GPIOs claimed by kernel code may be exported by its owner using a new gpio_export() call, which should be most useful for driver debugging. Such exports may optionally be done without a "direction" attribute. Userspace may ask to take over a GPIO by writing to a sysfs control file, helping to cope with incomplete board support or other "one-off" requirements that don't merit full kernel support: echo 23 > /sys/class/gpio/export ... will gpio_request(23, "sysfs") and gpio_export(23); use /sys/class/gpio/gpio-23/direction to (re)configure it, when that GPIO can be used as both input and output. echo 23 > /sys/class/gpio/unexport ... will gpio_free(23), when it was exported as above The extra D-space footprint is a few hundred bytes, except for the sysfs resources associated with each exported GPIO. The additional I-space footprint is about two thirds of the current size of gpiolib (!). Since no /dev node creation is involved, no "udev" support is needed. Related changes: * This adds a device pointer to "struct gpio_chip". When GPIO providers initialize that, sysfs gpio class devices become children of that device instead of being "virtual" devices. * The (few) gpio_chip providers which have such a device node have been updated. * Some gpio_chip drivers also needed to update their module "owner" field ... for which missing kerneldoc was added. * Some gpio_chips don't support input GPIOs. Those GPIOs are now flagged appropriately when the chip is registered. Based on previous patches, and discussion both on and off LKML. A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this merges to mainline. [akpm@linux-foundation.org: a few maintenance build fixes] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 12:46:07 +04:00
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 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 void
gpiochip_remove_pin_ranges(struct gpio_chip *chip)
{
WARN_ON(1);
}
#endif /* ! CONFIG_GENERIC_GPIO */
#endif /* __LINUX_GPIO_H */