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
gpiod_add_lookup_table(struct gpiod_lookup_table * table)118 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
119 static inline
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)120 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
121 static inline
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)122 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
gpiod_add_hogs(struct gpiod_hog * hogs)123 static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
gpiod_remove_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 */
128