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/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
  46 static inline bool gpio_is_valid(int number)
  47 {
  48         return number >= 0 && number < ARCH_NR_GPIOS;
  49 }
  50
  51 struct device;
  52 struct gpio;
  53 struct seq_file;
  54 struct module;
  55 struct device_node;
  56 struct gpio_desc;
  57
  58 /* caller holds gpio_lock *OR* gpio is marked as requested */
  59 static 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  */
  67 extern int gpio_request(unsigned gpio, const char *label);
  68 extern void gpio_free(unsigned gpio);
  69
  70 static inline int gpio_direction_input(unsigned gpio)
  71 {
  72         return gpiod_direction_input(gpio_to_desc(gpio));
  73 }
  74 static inline int gpio_direction_output(unsigned gpio, int value)
  75 {
  76         return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
  77 }
  78
  79 static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
  80 {
  81         return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
  82 }
  83
  84 static inline int gpio_get_value_cansleep(unsigned gpio)
  85 {
  86         return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
  87 }
  88 static 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  */
  98 static inline int __gpio_get_value(unsigned gpio)
  99 {
 100         return gpiod_get_raw_value(gpio_to_desc(gpio));
 101 }
 102 static inline void __gpio_set_value(unsigned gpio, int value)
 103 {
 104         return gpiod_set_raw_value(gpio_to_desc(gpio), value);
 105 }
 106
 107 static inline int __gpio_cansleep(unsigned gpio)
 108 {
 109         return gpiod_cansleep(gpio_to_desc(gpio));
 110 }
 111
 112 static inline int __gpio_to_irq(unsigned gpio)
 113 {
 114         return gpiod_to_irq(gpio_to_desc(gpio));
 115 }
 116
 117 extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 118 extern int gpio_request_array(const struct gpio *array, size_t num);
 119 extern 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  */
 125 static inline int gpio_export(unsigned gpio, bool direction_may_change)
 126 {
 127         return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 128 }
 129
 130 static 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
 136 static inline void gpio_unexport(unsigned gpio)
 137 {
 138         gpiod_unexport(gpio_to_desc(gpio));
 139 }
 140
 141 #else   /* !CONFIG_GPIOLIB */
 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 */