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 	GPIO_PULL_UP			= (1 << 4),
16 	GPIO_PULL_DOWN			= (1 << 5),
17 	GPIO_PULL_DISABLE		= (1 << 6),
18 
19 	GPIO_LOOKUP_FLAGS_DEFAULT	= GPIO_ACTIVE_HIGH | GPIO_PERSISTENT,
20 };
21 
22 /**
23  * struct gpiod_lookup - lookup table
24  * @key: either the name of the chip the GPIO belongs to, or the GPIO line name
25  *       Note that GPIO line names are not guaranteed to be globally unique,
26  *       so this will use the first match found!
27  * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO, or
28  *              U16_MAX to indicate that @key is a GPIO line name
29  * @con_id: name of the GPIO from the device's point of view
30  * @idx: index of the GPIO in case several GPIOs share the same name
31  * @flags: bitmask of gpio_lookup_flags GPIO_* values
32  *
33  * gpiod_lookup is a lookup table for associating GPIOs to specific devices and
34  * functions using platform data.
35  */
36 struct gpiod_lookup {
37 	const char *key;
38 	u16 chip_hwnum;
39 	const char *con_id;
40 	unsigned int idx;
41 	unsigned long flags;
42 };
43 
44 struct gpiod_lookup_table {
45 	struct list_head list;
46 	const char *dev_id;
47 	struct gpiod_lookup table[];
48 };
49 
50 /**
51  * struct gpiod_hog - GPIO line hog table
52  * @chip_label: name of the chip the GPIO belongs to
53  * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO
54  * @line_name: consumer name for the hogged line
55  * @lflags: bitmask of gpio_lookup_flags GPIO_* values
56  * @dflags: GPIO flags used to specify the direction and value
57  */
58 struct gpiod_hog {
59 	struct list_head list;
60 	const char *chip_label;
61 	u16 chip_hwnum;
62 	const char *line_name;
63 	unsigned long lflags;
64 	int dflags;
65 };
66 
67 /*
68  * Helper for lookup tables with just one single lookup for a device.
69  */
70 #define GPIO_LOOKUP_SINGLE(_name, _dev_id, _key, _chip_hwnum, _con_id, _flags) \
71 static struct gpiod_lookup_table _name = {				\
72 	.dev_id = _dev_id,						\
73 	.table = {							\
74 		GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags),	\
75 		{},							\
76 	},								\
77 }
78 
79 /*
80  * Simple definition of a single GPIO under a con_id
81  */
82 #define GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags) \
83 	GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, 0, _flags)
84 
85 /*
86  * Use this macro if you need to have several GPIOs under the same con_id.
87  * Each GPIO needs to use a different index and can be accessed using
88  * gpiod_get_index()
89  */
90 #define GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, _idx, _flags)         \
91 (struct gpiod_lookup) {                                                   \
92 	.key = _key,                                                      \
93 	.chip_hwnum = _chip_hwnum,                                        \
94 	.con_id = _con_id,                                                \
95 	.idx = _idx,                                                      \
96 	.flags = _flags,                                                  \
97 }
98 
99 /*
100  * Simple definition of a single GPIO hog in an array.
101  */
102 #define GPIO_HOG(_chip_label, _chip_hwnum, _line_name, _lflags, _dflags)  \
103 (struct gpiod_hog) {                                                      \
104 	.chip_label = _chip_label,                                        \
105 	.chip_hwnum = _chip_hwnum,                                        \
106 	.line_name = _line_name,                                          \
107 	.lflags = _lflags,                                                \
108 	.dflags = _dflags,                                                \
109 }
110 
111 #ifdef CONFIG_GPIOLIB
112 void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
113 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
114 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
115 void gpiod_add_hogs(struct gpiod_hog *hogs);
116 void gpiod_remove_hogs(struct gpiod_hog *hogs);
117 #else /* ! CONFIG_GPIOLIB */
118 static inline
gpiod_add_lookup_table(struct gpiod_lookup_table * table)119 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
120 static inline
gpiod_add_lookup_tables(struct gpiod_lookup_table ** tables,size_t n)121 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
122 static inline
gpiod_remove_lookup_table(struct gpiod_lookup_table * table)123 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
gpiod_add_hogs(struct gpiod_hog * hogs)124 static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
gpiod_remove_hogs(struct gpiod_hog * hogs)125 static inline void gpiod_remove_hogs(struct gpiod_hog *hogs) {}
126 #endif /* CONFIG_GPIOLIB */
127 
128 #endif /* __LINUX_GPIO_MACHINE_H */
129