diff options
Diffstat (limited to 'kernel/include/asm-generic/gpio.h')
-rw-r--r-- | kernel/include/asm-generic/gpio.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/kernel/include/asm-generic/gpio.h b/kernel/include/asm-generic/gpio.h new file mode 100644 index 000000000..9bb0d1172 --- /dev/null +++ b/kernel/include/asm-generic/gpio.h @@ -0,0 +1,172 @@ +#ifndef _ASM_GENERIC_GPIO_H +#define _ASM_GENERIC_GPIO_H + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/of.h> + +#ifdef CONFIG_GPIOLIB + +#include <linux/compiler.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/consumer.h> + +/* Platforms may implement their GPIO interface with library code, + * at a small performance cost for non-inlined operations and some + * extra memory (for code and for per-GPIO table entries). + * + * While the GPIO programming interface defines valid GPIO numbers + * to be in the range 0..MAX_INT, this library restricts them to the + * smaller range 0..ARCH_NR_GPIOS-1. + * + * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of + * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is + * actually an estimate of a board-specific value. + */ + +#ifndef ARCH_NR_GPIOS +#define ARCH_NR_GPIOS 512 +#endif + +/* + * "valid" GPIO numbers are nonnegative and may be passed to + * setup routines like gpio_request(). only some valid numbers + * can successfully be requested and used. + * + * Invalid GPIO numbers are useful for indicating no-such-GPIO in + * platform data and other tables. + */ + +static inline bool gpio_is_valid(int number) +{ + return number >= 0 && number < ARCH_NR_GPIOS; +} + +struct device; +struct gpio; +struct seq_file; +struct module; +struct device_node; +struct gpio_desc; + +/* caller holds gpio_lock *OR* gpio is marked as requested */ +static inline struct gpio_chip *gpio_to_chip(unsigned gpio) +{ + return gpiod_to_chip(gpio_to_desc(gpio)); +} + +/* Always use the library code for GPIO management calls, + * or when sleeping may be involved. + */ +extern int gpio_request(unsigned gpio, const char *label); +extern void gpio_free(unsigned gpio); + +static inline int gpio_direction_input(unsigned gpio) +{ + return gpiod_direction_input(gpio_to_desc(gpio)); +} +static inline int gpio_direction_output(unsigned gpio, int value) +{ + return gpiod_direction_output_raw(gpio_to_desc(gpio), value); +} + +static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + return gpiod_set_debounce(gpio_to_desc(gpio), debounce); +} + +static inline int gpio_get_value_cansleep(unsigned gpio) +{ + return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); +} +static inline void gpio_set_value_cansleep(unsigned gpio, int value) +{ + return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); +} + + +/* A platform's <asm/gpio.h> code may want to inline the I/O calls when + * the GPIO is constant and refers to some always-present controller, + * giving direct access to chip registers and tight bitbanging loops. + */ +static inline int __gpio_get_value(unsigned gpio) +{ + return gpiod_get_raw_value(gpio_to_desc(gpio)); +} +static inline void __gpio_set_value(unsigned gpio, int value) +{ + return gpiod_set_raw_value(gpio_to_desc(gpio), value); +} + +static inline int __gpio_cansleep(unsigned gpio) +{ + return gpiod_cansleep(gpio_to_desc(gpio)); +} + +static inline int __gpio_to_irq(unsigned gpio) +{ + return gpiod_to_irq(gpio_to_desc(gpio)); +} + +extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); +extern int gpio_request_array(const struct gpio *array, size_t num); +extern void gpio_free_array(const struct gpio *array, size_t num); + +/* + * A sysfs interface can be exported by individual drivers if they want, + * but more typically is configured entirely from userspace. + */ +static inline int gpio_export(unsigned gpio, bool direction_may_change) +{ + return gpiod_export(gpio_to_desc(gpio), direction_may_change); +} + +static inline int gpio_export_link(struct device *dev, const char *name, + unsigned gpio) +{ + return gpiod_export_link(dev, name, gpio_to_desc(gpio)); +} + +static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) +{ + return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); +} + +static inline void gpio_unexport(unsigned gpio) +{ + gpiod_unexport(gpio_to_desc(gpio)); +} + +#else /* !CONFIG_GPIOLIB */ + +static inline bool gpio_is_valid(int number) +{ + /* only non-negative numbers are valid */ + return number >= 0; +} + +/* platforms that don't directly support access to GPIOs through I2C, SPI, + * or other blocking infrastructure can use these wrappers. + */ + +static inline int gpio_cansleep(unsigned gpio) +{ + return 0; +} + +static inline int gpio_get_value_cansleep(unsigned gpio) +{ + might_sleep(); + return __gpio_get_value(gpio); +} + +static inline void gpio_set_value_cansleep(unsigned gpio, int value) +{ + might_sleep(); + __gpio_set_value(gpio, value); +} + +#endif /* !CONFIG_GPIOLIB */ + +#endif /* _ASM_GENERIC_GPIO_H */ |