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 #define ARCH_NR_GPIOS           512
  30 #endif
  31
  32 /*
  33  * "valid" GPIO numbers are nonnegative and may be passed to
  34  * setup routines like gpio_request().  only some valid numbers
  35  * can successfully be requested and used.
  36  *
  37  * Invalid GPIO numbers are useful for indicating no-such-GPIO in
  38  * platform data and other tables.
  39  */
  40
  41 static inline bool gpio_is_valid(int number)
  42 {
  43         return number >= 0 && number < ARCH_NR_GPIOS;
  44 }
  45
  46 struct device;
  47 struct gpio;
  48 struct seq_file;
  49 struct module;
  50 struct device_node;
  51 struct gpio_desc;
  52
  53 /* caller holds gpio_lock *OR* gpio is marked as requested */
  54 static inline struct gpio_chip *gpio_to_chip(unsigned gpio)
  55 {
  56         return gpiod_to_chip(gpio_to_desc(gpio));
  57 }
  58
  59 /* Always use the library code for GPIO management calls,
  60  * or when sleeping may be involved.
  61  */
  62 extern int gpio_request(unsigned gpio, const char *label);
  63 extern void gpio_free(unsigned gpio);
  64
  65 static inline int gpio_direction_input(unsigned gpio)
  66 {
  67         return gpiod_direction_input(gpio_to_desc(gpio));
  68 }
  69 static inline int gpio_direction_output(unsigned gpio, int value)
  70 {
  71         return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
  72 }
  73
  74 static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
  75 {
  76         return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
  77 }
  78
  79 static inline int gpio_get_value_cansleep(unsigned gpio)
  80 {
  81         return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio));
  82 }
  83 static inline void gpio_set_value_cansleep(unsigned gpio, int value)
  84 {
  85         return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value);
  86 }
  87
  88
  89 /* A platform's <asm/gpio.h> code may want to inline the I/O calls when
  90  * the GPIO is constant and refers to some always-present controller,
  91  * giving direct access to chip registers and tight bitbanging loops.
  92  */
  93 static inline int __gpio_get_value(unsigned gpio)
  94 {
  95         return gpiod_get_raw_value(gpio_to_desc(gpio));
  96 }
  97 static inline void __gpio_set_value(unsigned gpio, int value)
  98 {
  99         return gpiod_set_raw_value(gpio_to_desc(gpio), value);
 100 }
 101
 102 static inline int __gpio_cansleep(unsigned gpio)
 103 {
 104         return gpiod_cansleep(gpio_to_desc(gpio));
 105 }
 106
 107 static inline int __gpio_to_irq(unsigned gpio)
 108 {
 109         return gpiod_to_irq(gpio_to_desc(gpio));
 110 }
 111
 112 extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 113 extern int gpio_request_array(const struct gpio *array, size_t num);
 114 extern void gpio_free_array(const struct gpio *array, size_t num);
 115
 116 /*
 117  * A sysfs interface can be exported by individual drivers if they want,
 118  * but more typically is configured entirely from userspace.
 119  */
 120 static inline int gpio_export(unsigned gpio, bool direction_may_change)
 121 {
 122         return gpiod_export(gpio_to_desc(gpio), direction_may_change);
 123 }
 124
 125 static inline int gpio_export_link(struct device *dev, const char *name,
 126                                    unsigned gpio)
 127 {
 128         return gpiod_export_link(dev, name, gpio_to_desc(gpio));
 129 }
 130
 131 static inline void gpio_unexport(unsigned gpio)
 132 {
 133         gpiod_unexport(gpio_to_desc(gpio));
 134 }
 135
 136 #else   /* !CONFIG_GPIOLIB */
 137
 138 static inline bool gpio_is_valid(int number)
 139 {
 140         /* only non-negative numbers are valid */
 141         return number >= 0;
 142 }
 143
 144 /* platforms that don't directly support access to GPIOs through I2C, SPI,
 145  * or other blocking infrastructure can use these wrappers.
 146  */
 147
 148 static inline int gpio_cansleep(unsigned gpio)
 149 {
 150         return 0;
 151 }
 152
 153 static inline int gpio_get_value_cansleep(unsigned gpio)
 154 {
 155         might_sleep();
 156         return __gpio_get_value(gpio);
 157 }
 158
 159 static inline void gpio_set_value_cansleep(unsigned gpio, int value)
 160 {
 161         might_sleep();
 162         __gpio_set_value(gpio, value);
 163 }
 164
 165 #endif /* !CONFIG_GPIOLIB */
 166
 167 #endif /* _ASM_GENERIC_GPIO_H */