xref: /openbmc/linux/include/linux/gpio/machine.h (revision 08a149c4)
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