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
  7enum 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 */
 35struct 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
 43struct 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 */
 57struct 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) \
 70static 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
111void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
112void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
113void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
114void gpiod_add_hogs(struct gpiod_hog *hogs);
115void gpiod_remove_hogs(struct gpiod_hog *hogs);
116#else /* ! CONFIG_GPIOLIB */
117static inline
118void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
119static inline
120void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
121static inline
122void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
123static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
124static inline void gpiod_remove_hogs(struct gpiod_hog *hogs) {}
125#endif /* CONFIG_GPIOLIB */
126
127#endif /* __LINUX_GPIO_MACHINE_H */