311 lines
9.6 KiB
C
311 lines
9.6 KiB
C
#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>
|
|
#include <linux/pinctrl/pinctrl.h>
|
|
|
|
#ifdef CONFIG_GPIOLIB
|
|
|
|
#include <linux/compiler.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 256
|
|
#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_chip - abstract a GPIO controller
|
|
* @label: for diagnostics
|
|
* @dev: optional device providing the GPIOs
|
|
* @owner: helps prevent removal of modules exporting active GPIOs
|
|
* @request: optional hook for chip-specific activation, such as
|
|
* enabling module power and clock; may sleep
|
|
* @free: optional hook for chip-specific deactivation, such as
|
|
* disabling module power and clock; may sleep
|
|
* @get_direction: returns direction for signal "offset", 0=out, 1=in,
|
|
* (same as GPIOF_DIR_XXX), or negative error
|
|
* @direction_input: configures signal "offset" as input, or returns error
|
|
* @get: returns value for signal "offset"; for output signals this
|
|
* returns either the value actually sensed, or zero
|
|
* @direction_output: configures signal "offset" as output, or returns error
|
|
* @set_debounce: optional hook for setting debounce time for specified gpio in
|
|
* interrupt triggered gpio chips
|
|
* @set: assigns output value for signal "offset"
|
|
* @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
|
|
* implementation may not sleep
|
|
* @dbg_show: optional routine to show contents in debugfs; default code
|
|
* will be used when this is omitted, but custom code can show extra
|
|
* state (such as pullup/pulldown configuration).
|
|
* @base: identifies the first GPIO number handled by this chip; or, if
|
|
* negative during registration, requests dynamic ID allocation.
|
|
* @ngpio: the number of GPIOs handled by this controller; the last GPIO
|
|
* handled is (base + ngpio - 1).
|
|
* @can_sleep: flag must be set iff get()/set() methods sleep, as they
|
|
* must while accessing GPIO expander chips over I2C or SPI
|
|
* @names: if set, must be an array of strings to use as alternative
|
|
* names for the GPIOs in this chip. Any entry in the array
|
|
* may be NULL if there is no alias for the GPIO, however the
|
|
* array must be @ngpio entries long. A name can include a single printk
|
|
* format specifier for an unsigned int. It is substituted by the actual
|
|
* number of the gpio.
|
|
*
|
|
* A gpio_chip can help platforms abstract various sources of GPIOs so
|
|
* they can all be accessed through a common programing interface.
|
|
* Example sources would be SOC controllers, FPGAs, multifunction
|
|
* chips, dedicated GPIO expanders, and so on.
|
|
*
|
|
* Each chip controls a number of signals, identified in method calls
|
|
* by "offset" values in the range 0..(@ngpio - 1). When those signals
|
|
* are referenced through calls like gpio_get_value(gpio), the offset
|
|
* is calculated by subtracting @base from the gpio number.
|
|
*/
|
|
struct gpio_chip {
|
|
const char *label;
|
|
struct device *dev;
|
|
struct module *owner;
|
|
|
|
int (*request)(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
void (*free)(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
int (*get_direction)(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
int (*direction_input)(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
int (*get)(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
int (*direction_output)(struct gpio_chip *chip,
|
|
unsigned offset, int value);
|
|
int (*set_debounce)(struct gpio_chip *chip,
|
|
unsigned offset, unsigned debounce);
|
|
|
|
void (*set)(struct gpio_chip *chip,
|
|
unsigned offset, int value);
|
|
|
|
int (*to_irq)(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
|
|
void (*dbg_show)(struct seq_file *s,
|
|
struct gpio_chip *chip);
|
|
int base;
|
|
u16 ngpio;
|
|
const char *const *names;
|
|
unsigned can_sleep:1;
|
|
unsigned exported:1;
|
|
|
|
#if defined(CONFIG_OF_GPIO)
|
|
/*
|
|
* If CONFIG_OF is enabled, then all GPIO controllers described in the
|
|
* device tree automatically may have an OF translation
|
|
*/
|
|
struct device_node *of_node;
|
|
int of_gpio_n_cells;
|
|
int (*of_xlate)(struct gpio_chip *gc,
|
|
const struct of_phandle_args *gpiospec, u32 *flags);
|
|
#endif
|
|
#ifdef CONFIG_PINCTRL
|
|
/*
|
|
* If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
|
|
* describe the actual pin range which they serve in an SoC. This
|
|
* information would be used by pinctrl subsystem to configure
|
|
* corresponding pins for gpio usage.
|
|
*/
|
|
struct list_head pin_ranges;
|
|
#endif
|
|
};
|
|
|
|
extern const char *gpiochip_is_requested(struct gpio_chip *chip,
|
|
unsigned offset);
|
|
extern struct gpio_chip *gpio_to_chip(unsigned gpio);
|
|
extern int __must_check gpiochip_reserve(int start, int ngpio);
|
|
|
|
/* add/remove chips */
|
|
extern int gpiochip_add(struct gpio_chip *chip);
|
|
extern int __must_check gpiochip_remove(struct gpio_chip *chip);
|
|
extern struct gpio_chip *gpiochip_find(void *data,
|
|
int (*match)(struct gpio_chip *chip,
|
|
void *data));
|
|
|
|
|
|
/* 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);
|
|
|
|
extern int gpio_direction_input(unsigned gpio);
|
|
extern int gpio_direction_output(unsigned gpio, int value);
|
|
|
|
extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
|
|
|
|
extern int gpio_get_value_cansleep(unsigned gpio);
|
|
extern void gpio_set_value_cansleep(unsigned gpio, int 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.
|
|
*/
|
|
extern int __gpio_get_value(unsigned gpio);
|
|
extern void __gpio_set_value(unsigned gpio, int value);
|
|
|
|
extern int __gpio_cansleep(unsigned gpio);
|
|
|
|
extern int __gpio_to_irq(unsigned 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);
|
|
|
|
/* bindings for managed devices that want to request gpios */
|
|
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);
|
|
|
|
#ifdef CONFIG_GPIO_SYSFS
|
|
|
|
/*
|
|
* A sysfs interface can be exported by individual drivers if they want,
|
|
* but more typically is configured entirely from userspace.
|
|
*/
|
|
extern int gpio_export(unsigned gpio, bool direction_may_change);
|
|
extern int gpio_export_link(struct device *dev, const char *name,
|
|
unsigned gpio);
|
|
extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
|
|
extern void gpio_unexport(unsigned gpio);
|
|
|
|
#endif /* CONFIG_GPIO_SYSFS */
|
|
|
|
#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 */
|
|
|
|
#ifndef CONFIG_GPIO_SYSFS
|
|
|
|
struct device;
|
|
|
|
/* sysfs support is only available with gpiolib, where it's optional */
|
|
|
|
static inline int gpio_export(unsigned gpio, bool direction_may_change)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline int gpio_export_link(struct device *dev, const char *name,
|
|
unsigned gpio)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline int gpio_sysfs_set_active_low(unsigned gpio, int value)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline void gpio_unexport(unsigned gpio)
|
|
{
|
|
}
|
|
#endif /* CONFIG_GPIO_SYSFS */
|
|
|
|
#ifdef CONFIG_PINCTRL
|
|
|
|
/**
|
|
* struct gpio_pin_range - pin range controlled by a gpio chip
|
|
* @head: list for maintaining set of pin ranges, used internally
|
|
* @pctldev: pinctrl device which handles corresponding pins
|
|
* @range: actual range of pins controlled by a gpio controller
|
|
*/
|
|
|
|
struct gpio_pin_range {
|
|
struct list_head node;
|
|
struct pinctrl_dev *pctldev;
|
|
struct pinctrl_gpio_range range;
|
|
};
|
|
|
|
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
|
|
unsigned int gpio_offset, unsigned int pin_offset,
|
|
unsigned int npins);
|
|
void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
|
|
|
|
#else
|
|
|
|
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)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void
|
|
gpiochip_remove_pin_ranges(struct gpio_chip *chip)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_PINCTRL */
|
|
|
|
#endif /* _ASM_GENERIC_GPIO_H */
|