include/linux/gpio/machine.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_GPIO_MACHINE_H
   3 #define __LINUX_GPIO_MACHINE_H
   4
   5 #include <linux/types.h>
   6
   7 enum gpio_lookup_flags {
   8         GPIO_ACTIVE_HIGH                = (0 << 0),
   9         GPIO_ACTIVE_LOW                 = (1 << 0),
  10         GPIO_OPEN_DRAIN                 = (1 << 1),
  11         GPIO_OPEN_SOURCE                = (1 << 2),
  12         GPIO_PERSISTENT                 = (0 << 3),
  13         GPIO_TRANSITORY                 = (1 << 3),
  14         GPIO_PULL_UP                    = (1 << 4),
  15         GPIO_PULL_DOWN                  = (1 << 5),
  16         GPIO_PULL_DISABLE               = (1 << 6),
  17
  18         GPIO_LOOKUP_FLAGS_DEFAULT       = GPIO_ACTIVE_HIGH | GPIO_PERSISTENT,
  19 };
  20
  21 /**
  22  * struct gpiod_lookup - lookup table
  23  * @key: either the name of the chip the GPIO belongs to, or the GPIO line name
  24  *       Note that GPIO line names are not guaranteed to be globally unique,
  25  *       so this will use the first match found!
  26  * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO, or
  27  *              U16_MAX to indicate that @key is a GPIO line name
  28  * @con_id: name of the GPIO from the device's point of view
  29  * @idx: index of the GPIO in case several GPIOs share the same name
  30  * @flags: bitmask of gpio_lookup_flags GPIO_* values
  31  *
  32  * gpiod_lookup is a lookup table for associating GPIOs to specific devices and
  33  * functions using platform data.
  34  */
  35 struct gpiod_lookup {
  36         const char *key;
  37         u16 chip_hwnum;
  38         const char *con_id;
  39         unsigned int idx;
  40         unsigned long flags;
  41 };
  42
  43 struct gpiod_lookup_table {
  44         struct list_head list;
  45         const char *dev_id;
  46         struct gpiod_lookup table[];
  47 };
  48
  49 /**
  50  * struct gpiod_hog - GPIO line hog table
  51  * @chip_label: name of the chip the GPIO belongs to
  52  * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO
  53  * @line_name: consumer name for the hogged line
  54  * @lflags: bitmask of gpio_lookup_flags GPIO_* values
  55  * @dflags: GPIO flags used to specify the direction and value
  56  */
  57 struct gpiod_hog {
  58         struct list_head list;
  59         const char *chip_label;
  60         u16 chip_hwnum;
  61         const char *line_name;
  62         unsigned long lflags;
  63         int dflags;
  64 };
  65
  66 /*
  67  * Helper for lookup tables with just one single lookup for a device.
  68  */
  69 #define GPIO_LOOKUP_SINGLE(_name, _dev_id, _key, _chip_hwnum, _con_id, _flags) \
  70 static struct gpiod_lookup_table _name = {                              \
  71         .dev_id = _dev_id,                                              \
  72         .table = {                                                      \
  73                 GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags),        \
  74                 {},                                                     \
  75         },                                                              \
  76 }
  77
  78 /*
  79  * Simple definition of a single GPIO under a con_id
  80  */
  81 #define GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags) \
  82         GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, 0, _flags)
  83
  84 /*
  85  * Use this macro if you need to have several GPIOs under the same con_id.
  86  * Each GPIO needs to use a different index and can be accessed using
  87  * gpiod_get_index()
  88  */
  89 #define GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, _idx, _flags)         \
  90 (struct gpiod_lookup) {                                                   \
  91         .key = _key,                                                      \
  92         .chip_hwnum = _chip_hwnum,                                        \
  93         .con_id = _con_id,                                                \
  94         .idx = _idx,                                                      \
  95         .flags = _flags,                                                  \
  96 }
  97
  98 /*
  99  * Simple definition of a single GPIO hog in an array.
 100  */
 101 #define GPIO_HOG(_chip_label, _chip_hwnum, _line_name, _lflags, _dflags)  \
 102 (struct gpiod_hog) {                                                      \
 103         .chip_label = _chip_label,                                        \
 104         .chip_hwnum = _chip_hwnum,                                        \
 105         .line_name = _line_name,                                          \
 106         .lflags = _lflags,                                                \
 107         .dflags = _dflags,                                                \
 108 }
 109
 110 #ifdef CONFIG_GPIOLIB
 111 void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
 112 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
 113 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
 114 void gpiod_add_hogs(struct gpiod_hog *hogs);
 115 void gpiod_remove_hogs(struct gpiod_hog *hogs);
 116 #else /* ! CONFIG_GPIOLIB */
 117 static inline
 118 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
 119 static inline
 120 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
 121 static inline
 122 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
 123 static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
 124 static inline void gpiod_remove_hogs(struct gpiod_hog *hogs) {}
 125 #endif /* CONFIG_GPIOLIB */
 126
 127 #endif /* __LINUX_GPIO_MACHINE_H */