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 #include <linux/list.h>
   7
   8 enum gpio_lookup_flags {
   9         GPIO_ACTIVE_HIGH = (0 << 0),
  10         GPIO_ACTIVE_LOW = (1 << 0),
  11         GPIO_OPEN_DRAIN = (1 << 1),
  12         GPIO_OPEN_SOURCE = (1 << 2),
  13         GPIO_PERSISTENT = (0 << 3),
  14         GPIO_TRANSITORY = (1 << 3),
  15 };
  16
  17 /**
  18  * struct gpiod_lookup - lookup table
  19  * @chip_label: name of the chip the GPIO belongs to
  20  * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO
  21  * @con_id: name of the GPIO from the device's point of view
  22  * @idx: index of the GPIO in case several GPIOs share the same name
  23  * @flags: mask of GPIO_* values
  24  *
  25  * gpiod_lookup is a lookup table for associating GPIOs to specific devices and
  26  * functions using platform data.
  27  */
  28 struct gpiod_lookup {
  29         const char *chip_label;
  30         u16 chip_hwnum;
  31         const char *con_id;
  32         unsigned int idx;
  33         enum gpio_lookup_flags flags;
  34 };
  35
  36 struct gpiod_lookup_table {
  37         struct list_head list;
  38         const char *dev_id;
  39         struct gpiod_lookup table[];
  40 };
  41
  42 /*
  43  * Simple definition of a single GPIO under a con_id
  44  */
  45 #define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \
  46         GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags)
  47
  48 /*
  49  * Use this macro if you need to have several GPIOs under the same con_id.
  50  * Each GPIO needs to use a different index and can be accessed using
  51  * gpiod_get_index()
  52  */
  53 #define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags)  \
  54 {                                                                         \
  55         .chip_label = _chip_label,                                        \
  56         .chip_hwnum = _chip_hwnum,                                        \
  57         .con_id = _con_id,                                                \
  58         .idx = _idx,                                                      \
  59         .flags = _flags,                                                  \
  60 }
  61
  62 #ifdef CONFIG_GPIOLIB
  63 void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
  64 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
  65 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
  66 #else
  67 static inline
  68 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
  69 static inline
  70 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
  71 static inline
  72 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
  73 #endif
  74
  75 #endif /* __LINUX_GPIO_MACHINE_H */