mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-26 06:04:14 +08:00
7560fa60fc
Add a <linux/gpio.h> defining fail/warn stubs for GPIO calls on platforms that don't support the GPIO programming interface. That includes the arch-specific implementation glue otherwise. This facilitates a new model for GPIO usage: drivers that can use GPIOs if they're available, but don't require them. One example of such a driver is NAND driver for various FreeScale chips. On platforms update with GPIO support, they can be used instead of a worst-case delay to verify that the BUSY signal is off. (Also includes a couple minor unrelated doc updates.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
96 lines
1.8 KiB
C
96 lines
1.8 KiB
C
#ifndef __LINUX_GPIO_H
|
|
#define __LINUX_GPIO_H
|
|
|
|
/* see Documentation/gpio.txt */
|
|
|
|
#ifdef CONFIG_GENERIC_GPIO
|
|
#include <asm/gpio.h>
|
|
|
|
#else
|
|
|
|
/*
|
|
* Some platforms don't support the GPIO programming interface.
|
|
*
|
|
* In case some driver uses it anyway (it should normally have
|
|
* depended on GENERIC_GPIO), these routines help the compiler
|
|
* optimize out much GPIO-related code ... or trigger a runtime
|
|
* warning when something is wrongly called.
|
|
*/
|
|
|
|
static inline int gpio_is_valid(int number)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int gpio_request(unsigned gpio, const char *label)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline void gpio_free(unsigned gpio)
|
|
{
|
|
/* 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_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_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;
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif /* __LINUX_GPIO_H */
|