1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_GENERIC_GPIO_H
  3#define _ASM_GENERIC_GPIO_H
  4
  5#include <linux/kernel.h>
  6#include <linux/types.h>
  7#include <linux/errno.h>
  8#include <linux/of.h>
  9
 10#ifdef CONFIG_GPIOLIB
 11
 12#include <linux/compiler.h>
 13#include <linux/gpio/driver.h>
 14#include <linux/gpio/consumer.h>
 15
 16/* Platforms may implement their GPIO interface with library code,
 17 * at a small performance cost for non-inlined operations and some
 18 * extra memory (for code and for per-GPIO table entries).
 19 *
 20 * While the GPIO programming interface defines valid GPIO numbers
 21 * to be in the range 0..MAX_INT, this library restricts them to the
 22 * smaller range 0..ARCH_NR_GPIOS-1.
 23 *
 24 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
 25 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
 26 * actually an estimate of a board-specific value.
 27 */
 28
 29#ifndef ARCH_NR_GPIOS
 30#if defined(CONFIG_ARCH_NR_GPIO) && CONFIG_ARCH_NR_GPIO > 0
 31#define ARCH_NR_GPIOS CONFIG_ARCH_NR_GPIO
 32#else
 33#define ARCH_NR_GPIOS		512
 34#endif
 35#endif
 36
 37/*
 38 * "valid" GPIO numbers are nonnegative and may be passed to
 39 * setup routines like gpio_request().  only some valid numbers
 40 * can successfully be requested and used.
 41 *
 42 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
 43 * platform data and other tables.
 44 */
 45
 46static inline bool gpio_is_valid(int number)
 47{
 48	return number >= 0 && number < ARCH_NR_GPIOS;
 49}
 50
 51struct device;
 52struct gpio;
 53struct seq_file;
 54struct module;
 55struct device_node;
 56struct gpio_desc;
 57
 58/* caller holds gpio_lock *OR* gpio is marked as requested */
 59static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
 60{
 61	return gpiod_to_chip(gpio_to_desc(gpio));
 62}
 63
 64/* Always use the library code for GPIO management calls,
 65 * or when sleeping may be involved.
 66 */
 67extern int gpio_request(unsigned gpio, const char *label);
 68extern void gpio_free(unsigned gpio);
 69
 70static inline int gpio_direction_input(unsigned gpio)
 71{
 72	return gpiod_direction_input(gpio_to_desc(gpio));
 73}
 74static inline int gpio_direction_output(unsigned gpio, int value)
 75{
 76	return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
 77}
 78
 79static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
 80{
 81	return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
 82}
 83
 84static inline int gpio_get_value_cansleep(unsigned gpio)
 85{
 86	return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
 87}
 88static inline void gpio_set_value_cansleep(unsigned gpio, int value)
 89{
 90	return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
 91}
 92
 93
 94/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
 95 * the GPIO is constant and refers to some always-present controller,
 96 * giving direct access to chip registers and tight bitbanging loops.
 97 */
 98static inline int __gpio_get_value(unsigned gpio)
 99{
100	return gpiod_get_raw_value(gpio_to_desc(gpio));
101}
102static inline void __gpio_set_value(unsigned gpio, int value)
103{
104	return gpiod_set_raw_value(gpio_to_desc(gpio), value);
105}
106
107static inline int __gpio_cansleep(unsigned gpio)
108{
109	return gpiod_cansleep(gpio_to_desc(gpio));
110}
111
112static inline int __gpio_to_irq(unsigned gpio)
113{
114	return gpiod_to_irq(gpio_to_desc(gpio));
115}
116
117extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
118extern int gpio_request_array(const struct gpio *array, size_t num);
119extern void gpio_free_array(const struct gpio *array, size_t num);
120
121/*
122 * A sysfs interface can be exported by individual drivers if they want,
123 * but more typically is configured entirely from userspace.
124 */
125static inline int gpio_export(unsigned gpio, bool direction_may_change)
126{
127	return gpiod_export(gpio_to_desc(gpio), direction_may_change);
128}
129
130static inline int gpio_export_link(struct device *dev, const char *name,
131				   unsigned gpio)
132{
133	return gpiod_export_link(dev, name, gpio_to_desc(gpio));
134}
135
136static inline void gpio_unexport(unsigned gpio)
137{
138	gpiod_unexport(gpio_to_desc(gpio));
139}
140
141#else	/* !CONFIG_GPIOLIB */
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 */