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