include/asm-generic/gpio.h

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