gpio.h 4.4 KB

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