aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/include/uapi/linux/gpio.h
blob: 0206383c0383fa3884c9ab581a321723527d6ce1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * <linux/gpio.h> - userspace ABI for the GPIO character devices
 *
 * Copyright (C) 2016 Linus Walleij
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */
#ifndef _UAPI_GPIO_H_
#define _UAPI_GPIO_H_

#include <linux/ioctl.h>
#include <linux/types.h>

/**
 * struct gpiochip_info - Information about a certain GPIO chip
 * @name: the Linux kernel name of this GPIO chip
 * @label: a functional name for this GPIO chip, such as a product
 * number, may be empty
 * @lines: number of GPIO lines on this chip
 */
struct gpiochip_info {
	char name[32];
	char label[32];
	__u32 lines;
};

/* Informational flags */
#define GPIOLINE_FLAG_KERNEL		(1UL << 0) /* Line used by the kernel */
#define GPIOLINE_FLAG_IS_OUT		(1UL << 1)
#define GPIOLINE_FLAG_ACTIVE_LOW	(1UL << 2)
#define GPIOLINE_FLAG_OPEN_DRAIN	(1UL << 3)
#define GPIOLINE_FLAG_OPEN_SOURCE	(1UL << 4)
#define GPIOLINE_FLAG_BIAS_PULL_UP	(1UL << 5)
#define GPIOLINE_FLAG_BIAS_PULL_DOWN	(1UL << 6)
#define GPIOLINE_FLAG_BIAS_DISABLE	(1UL << 7)

/**
 * struct gpioline_info - Information about a certain GPIO line
 * @line_offset: the local offset on this GPIO device, fill this in when
 * requesting the line information from the kernel
 * @flags: various flags for this line
 * @name: the name of this GPIO line, such as the output pin of the line on the
 * chip, a rail or a pin header name on a board, as specified by the gpio
 * chip, may be empty
 * @consumer: a functional name for the consumer of this GPIO line as set by
 * whatever is using it, will be empty if there is no current user but may
 * also be empty if the consumer doesn't set this up
 */
struct gpioline_info {
	__u32 line_offset;
	__u32 flags;
	char name[32];
	char consumer[32];
};

/* Maximum number of requested handles */
#define GPIOHANDLES_MAX 64

/* Possible line status change events */
enum {
	GPIOLINE_CHANGED_REQUESTED = 1,
	GPIOLINE_CHANGED_RELEASED,
	GPIOLINE_CHANGED_CONFIG,
};

/**
 * struct gpioline_info_changed - Information about a change in status
 * of a GPIO line
 * @info: updated line information
 * @timestamp: estimate of time of status change occurrence, in nanoseconds
 * and GPIOLINE_CHANGED_CONFIG
 * @event_type: one of GPIOLINE_CHANGED_REQUESTED, GPIOLINE_CHANGED_RELEASED
 *
 * Note: struct gpioline_info embedded here has 32-bit alignment on its own,
 * but it works fine with 64-bit alignment too. With its 72 byte size, we can
 * guarantee there are no implicit holes between it and subsequent members.
 * The 20-byte padding at the end makes sure we don't add any implicit padding
 * at the end of the structure on 64-bit architectures.
 */
struct gpioline_info_changed {
	struct gpioline_info info;
	__u64 timestamp;
	__u32 event_type;
	__u32 padding[5]; /* for future use */
};

/* Linerequest flags */
#define GPIOHANDLE_REQUEST_INPUT	(1UL << 0)
#define GPIOHANDLE_REQUEST_OUTPUT	(1UL << 1)
#define GPIOHANDLE_REQUEST_ACTIVE_LOW	(1UL << 2)
#define GPIOHANDLE_REQUEST_OPEN_DRAIN	(1UL << 3)
#define GPIOHANDLE_REQUEST_OPEN_SOURCE	(1UL << 4)
#define GPIOHANDLE_REQUEST_BIAS_PULL_UP	(1UL << 5)
#define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN	(1UL << 6)
#define GPIOHANDLE_REQUEST_BIAS_DISABLE	(1UL << 7)

/**
 * struct gpiohandle_request - Information about a GPIO handle request
 * @lineoffsets: an array of desired lines, specified by offset index for the
 * associated GPIO device
 * @flags: desired flags for the desired GPIO lines, such as
 * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed
 * together. Note that even if multiple lines are requested, the same flags
 * must be applicable to all of them, if you want lines with individual
 * flags set, request them one by one. It is possible to select
 * a batch of input or output lines, but they must all have the same
 * characteristics, i.e. all inputs or all outputs, all active low etc
 * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set for a requested
 * line, this specifies the default output value, should be 0 (low) or
 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
 * @consumer_label: a desired consumer label for the selected GPIO line(s)
 * such as "my-bitbanged-relay"
 * @lines: number of lines requested in this request, i.e. the number of
 * valid fields in the above arrays, set to 1 to request a single line
 * @fd: if successful this field will contain a valid anonymous file handle
 * after a GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value
 * means error
 */
struct gpiohandle_request {
	__u32 lineoffsets[GPIOHANDLES_MAX];
	__u32 flags;
	__u8 default_values[GPIOHANDLES_MAX];
	char consumer_label[32];
	__u32 lines;
	int fd;
};

/**
 * struct gpiohandle_config - Configuration for a GPIO handle request
 * @flags: updated flags for the requested GPIO lines, such as
 * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed
 * together
 * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set in flags,
 * this specifies the default output value, should be 0 (low) or
 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
 * @padding: reserved for future use and should be zero filled
 */
struct gpiohandle_config {
	__u32 flags;
	__u8 default_values[GPIOHANDLES_MAX];
	__u32 padding[4]; /* padding for future use */
};

#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0a, struct gpiohandle_config)

/**
 * struct gpiohandle_data - Information of values on a GPIO handle
 * @values: when getting the state of lines this contains the current
 * state of a line, when setting the state of lines these should contain
 * the desired target state
 */
struct gpiohandle_data {
	__u8 values[GPIOHANDLES_MAX];
};

#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)

/* Eventrequest flags */
#define GPIOEVENT_REQUEST_RISING_EDGE	(1UL << 0)
#define GPIOEVENT_REQUEST_FALLING_EDGE	(1UL << 1)
#define GPIOEVENT_REQUEST_BOTH_EDGES	((1UL << 0) | (1UL << 1))

/**
 * struct gpioevent_request - Information about a GPIO event request
 * @lineoffset: the desired line to subscribe to events from, specified by
 * offset index for the associated GPIO device
 * @handleflags: desired handle flags for the desired GPIO line, such as
 * GPIOHANDLE_REQUEST_ACTIVE_LOW or GPIOHANDLE_REQUEST_OPEN_DRAIN
 * @eventflags: desired flags for the desired GPIO event line, such as
 * GPIOEVENT_REQUEST_RISING_EDGE or GPIOEVENT_REQUEST_FALLING_EDGE
 * @consumer_label: a desired consumer label for the selected GPIO line(s)
 * such as "my-listener"
 * @fd: if successful this field will contain a valid anonymous file handle
 * after a GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value
 * means error
 */
struct gpioevent_request {
	__u32 lineoffset;
	__u32 handleflags;
	__u32 eventflags;
	char consumer_label[32];
	int fd;
};

/**
 * GPIO event types
 */
#define GPIOEVENT_EVENT_RISING_EDGE 0x01
#define GPIOEVENT_EVENT_FALLING_EDGE 0x02

/**
 * struct gpioevent_data - The actual event being pushed to userspace
 * @timestamp: best estimate of time of event occurrence, in nanoseconds
 * @id: event identifier
 */
struct gpioevent_data {
	__u64 timestamp;
	__u32 id;
};

#define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info)
#define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info)
#define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0b, struct gpioline_info)
#define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0c, __u32)
#define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request)
#define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request)

#endif /* _UAPI_GPIO_H_ */