1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_GENERIC_GPIO_H
  3#define _ASM_GENERIC_GPIO_H
  4
  5#include <linux/types.h>
  6#include <linux/errno.h>
  7
  8#ifdef CONFIG_GPIOLIB
  9
 10#include <linux/compiler.h>
 11#include <linux/gpio/driver.h>
 12#include <linux/gpio/consumer.h>
 13
 14/* Platforms may implement their GPIO interface with library code,
 15 * at a small performance cost for non-inlined operations and some
 16 * extra memory (for code and for per-GPIO table entries).
 17 *
 18 * While the GPIO programming interface defines valid GPIO numbers
 19 * to be in the range 0..MAX_INT, this library restricts them to the
 20 * smaller range 0..ARCH_NR_GPIOS-1.
 21 *
 22 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
 23 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
 24 * actually an estimate of a board-specific value.
 25 */
 26
 27#ifndef ARCH_NR_GPIOS
 28#if defined(CONFIG_ARCH_NR_GPIO) && CONFIG_ARCH_NR_GPIO > 0
 29#define ARCH_NR_GPIOS CONFIG_ARCH_NR_GPIO
 30#else
 31#define ARCH_NR_GPIOS		512
 32#endif
 33#endif
 34
 35/*
 36 * "valid" GPIO numbers are nonnegative and may be passed to
 37 * setup routines like gpio_request().  only some valid numbers
 38 * can successfully be requested and used.
 39 *
 40 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
 41 * platform data and other tables.
 42 */
 43
 44static inline bool gpio_is_valid(int number)
 45{
 46	return number >= 0 && number < ARCH_NR_GPIOS;
 47}
 48
 49struct device;
 50struct gpio;
 51struct seq_file;
 52struct module;
 53struct device_node;
 54struct gpio_desc;
 55
 56/* caller holds gpio_lock *OR* gpio is marked as requested */
 57static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
 58{
 59	return gpiod_to_chip(gpio_to_desc(gpio));
 60}
 61
 62/* Always use the library code for GPIO management calls,
 63 * or when sleeping may be involved.
 64 */
 65extern int gpio_request(unsigned gpio, const char *label);
 66extern void gpio_free(unsigned gpio);
 67
 68static inline int gpio_direction_input(unsigned gpio)
 69{
 70	return gpiod_direction_input(gpio_to_desc(gpio));
 71}
 72static inline int gpio_direction_output(unsigned gpio, int value)
 73{
 74	return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
 75}
 76
 77static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
 78{
 79	return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
 80}
 81
 82static inline int gpio_get_value_cansleep(unsigned gpio)
 83{
 84	return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
 85}
 86static inline void gpio_set_value_cansleep(unsigned gpio, int value)
 87{
 88	return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
 89}
 90
 91
 92/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
 93 * the GPIO is constant and refers to some always-present controller,
 94 * giving direct access to chip registers and tight bitbanging loops.
 95 */
 96static inline int __gpio_get_value(unsigned gpio)
 97{
 98	return gpiod_get_raw_value(gpio_to_desc(gpio));
 99}
100static inline void __gpio_set_value(unsigned gpio, int value)
101{
102	return gpiod_set_raw_value(gpio_to_desc(gpio), value);
103}
104
105static inline int __gpio_cansleep(unsigned gpio)
106{
107	return gpiod_cansleep(gpio_to_desc(gpio));
108}
109
110static inline int __gpio_to_irq(unsigned gpio)
111{
112	return gpiod_to_irq(gpio_to_desc(gpio));
113}
114
115extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
116extern int gpio_request_array(const struct gpio *array, size_t num);
117extern void gpio_free_array(const struct gpio *array, size_t num);
118
119/*
120 * A sysfs interface can be exported by individual drivers if they want,
121 * but more typically is configured entirely from userspace.
122 */
123static inline int gpio_export(unsigned gpio, bool direction_may_change)
124{
125	return gpiod_export(gpio_to_desc(gpio), direction_may_change);
126}
127
128static inline int gpio_export_link(struct device *dev, const char *name,
129				   unsigned gpio)
130{
131	return gpiod_export_link(dev, name, gpio_to_desc(gpio));
132}
133
134static inline void gpio_unexport(unsigned gpio)
135{
136	gpiod_unexport(gpio_to_desc(gpio));
137}
138
139#else	/* !CONFIG_GPIOLIB */
140
141#include <linux/kernel.h>
142
143static inline bool gpio_is_valid(int number)
144{
145	/* only non-negative numbers are valid */
146	return number >= 0;
147}
148
149/* platforms that don't directly support access to GPIOs through I2C, SPI,
150 * or other blocking infrastructure can use these wrappers.
151 */
152
153static inline int gpio_cansleep(unsigned gpio)
154{
155	return 0;
156}
157
158static inline int gpio_get_value_cansleep(unsigned gpio)
159{
160	might_sleep();
161	return __gpio_get_value(gpio);
162}
163
164static inline void gpio_set_value_cansleep(unsigned gpio, int value)
165{
166	might_sleep();
167	__gpio_set_value(gpio, value);
168}
169
170#endif /* !CONFIG_GPIOLIB */
171
172#endif /* _ASM_GENERIC_GPIO_H */