include/asm-generic/gpio.h

   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
  44 static inline bool gpio_is_valid(int number)
  45 {
  46         return number >= 0 && number < ARCH_NR_GPIOS;
  47 }
  48
  49 struct device;
  50 struct gpio;
  51 struct seq_file;
  52 struct module;
  53 struct device_node;
  54 struct gpio_desc;
  55
  56 /* caller holds gpio_lock *OR* gpio is marked as requested */
  57 static 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  */
  65 extern int gpio_request(unsigned gpio, const char *label);
  66 extern void gpio_free(unsigned gpio);
  67
  68 static inline int gpio_direction_input(unsigned gpio)
  69 {
  70         return gpiod_direction_input(gpio_to_desc(gpio));
  71 }
  72 static inline int gpio_direction_output(unsigned gpio, int value)
  73 {
  74         return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
  75 }
  76
  77 static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
  78 {
  79         return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
  80 }
  81
  82 static inline int gpio_get_value_cansleep(unsigned gpio)
  83 {
  84         return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
  85 }
  86 static 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  */
  96 static inline int __gpio_get_value(unsigned gpio)
  97 {
  98         return gpiod_get_raw_value(gpio_to_desc(gpio));
  99 }
 100 static inline void __gpio_set_value(unsigned gpio, int value)
 101 {
 102         return gpiod_set_raw_value(gpio_to_desc(gpio), value);
 103 }
 104
 105 static inline int __gpio_cansleep(unsigned gpio)
 106 {
 107         return gpiod_cansleep(gpio_to_desc(gpio));
 108 }
 109
 110 static inline int __gpio_to_irq(unsigned gpio)
 111 {
 112         return gpiod_to_irq(gpio_to_desc(gpio));
 113 }
 114
 115 extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 116 extern int gpio_request_array(const struct gpio *array, size_t num);
 117 extern 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  */
 123 static inline int gpio_export(unsigned gpio, bool direction_may_change)
 124 {
 125         return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 126 }
 127
 128 static 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
 134 static 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
 143 static 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
 153 static inline int gpio_cansleep(unsigned gpio)
 154 {
 155         return 0;
 156 }
 157
 158 static inline int gpio_get_value_cansleep(unsigned gpio)
 159 {
 160         might_sleep();
 161         return __gpio_get_value(gpio);
 162 }
 163
 164 static 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 */