1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
3 * <linux/gpio.h> - userspace ABI for the GPIO character devices
5 * Copyright (C) 2016 Linus Walleij
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
14 #include <linux/ioctl.h>
15 #include <linux/types.h>
18 * struct gpiochip_info - Information about a certain GPIO chip
19 * @name: the Linux kernel name of this GPIO chip
20 * @label: a functional name for this GPIO chip, such as a product
21 * number, may be empty
22 * @lines: number of GPIO lines on this chip
24 struct gpiochip_info {
30 /* Informational flags */
31 #define GPIOLINE_FLAG_KERNEL (1UL << 0) /* Line used by the kernel */
32 #define GPIOLINE_FLAG_IS_OUT (1UL << 1)
33 #define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2)
34 #define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3)
35 #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4)
36 #define GPIOLINE_FLAG_BIAS_PULL_UP (1UL << 5)
37 #define GPIOLINE_FLAG_BIAS_PULL_DOWN (1UL << 6)
38 #define GPIOLINE_FLAG_BIAS_DISABLE (1UL << 7)
41 * struct gpioline_info - Information about a certain GPIO line
42 * @line_offset: the local offset on this GPIO device, fill this in when
43 * requesting the line information from the kernel
44 * @flags: various flags for this line
45 * @name: the name of this GPIO line, such as the output pin of the line on the
46 * chip, a rail or a pin header name on a board, as specified by the gpio
48 * @consumer: a functional name for the consumer of this GPIO line as set by
49 * whatever is using it, will be empty if there is no current user but may
50 * also be empty if the consumer doesn't set this up
52 struct gpioline_info {
59 /* Maximum number of requested handles */
60 #define GPIOHANDLES_MAX 64
62 /* Possible line status change events */
64 GPIOLINE_CHANGED_REQUESTED = 1,
65 GPIOLINE_CHANGED_RELEASED,
66 GPIOLINE_CHANGED_CONFIG,
70 * struct gpioline_info_changed - Information about a change in status
72 * @info: updated line information
73 * @timestamp: estimate of time of status change occurrence, in nanoseconds
74 * @event_type: one of GPIOLINE_CHANGED_REQUESTED, GPIOLINE_CHANGED_RELEASED
75 * and GPIOLINE_CHANGED_CONFIG
77 * Note: struct gpioline_info embedded here has 32-bit alignment on its own,
78 * but it works fine with 64-bit alignment too. With its 72 byte size, we can
79 * guarantee there are no implicit holes between it and subsequent members.
80 * The 20-byte padding at the end makes sure we don't add any implicit padding
81 * at the end of the structure on 64-bit architectures.
83 struct gpioline_info_changed {
84 struct gpioline_info info;
87 __u32 padding[5]; /* for future use */
90 /* Linerequest flags */
91 #define GPIOHANDLE_REQUEST_INPUT (1UL << 0)
92 #define GPIOHANDLE_REQUEST_OUTPUT (1UL << 1)
93 #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2)
94 #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3)
95 #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4)
96 #define GPIOHANDLE_REQUEST_BIAS_PULL_UP (1UL << 5)
97 #define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6)
98 #define GPIOHANDLE_REQUEST_BIAS_DISABLE (1UL << 7)
101 * struct gpiohandle_request - Information about a GPIO handle request
102 * @lineoffsets: an array of desired lines, specified by offset index for the
103 * associated GPIO device
104 * @flags: desired flags for the desired GPIO lines, such as
105 * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed
106 * together. Note that even if multiple lines are requested, the same flags
107 * must be applicable to all of them, if you want lines with individual
108 * flags set, request them one by one. It is possible to select
109 * a batch of input or output lines, but they must all have the same
110 * characteristics, i.e. all inputs or all outputs, all active low etc
111 * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set for a requested
112 * line, this specifies the default output value, should be 0 (low) or
113 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
114 * @consumer_label: a desired consumer label for the selected GPIO line(s)
115 * such as "my-bitbanged-relay"
116 * @lines: number of lines requested in this request, i.e. the number of
117 * valid fields in the above arrays, set to 1 to request a single line
118 * @fd: if successful this field will contain a valid anonymous file handle
119 * after a GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value
122 struct gpiohandle_request {
123 __u32 lineoffsets[GPIOHANDLES_MAX];
125 __u8 default_values[GPIOHANDLES_MAX];
126 char consumer_label[32];
132 * struct gpiohandle_config - Configuration for a GPIO handle request
133 * @flags: updated flags for the requested GPIO lines, such as
134 * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed
136 * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set in flags,
137 * this specifies the default output value, should be 0 (low) or
138 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
139 * @padding: reserved for future use and should be zero filled
141 struct gpiohandle_config {
143 __u8 default_values[GPIOHANDLES_MAX];
144 __u32 padding[4]; /* padding for future use */
147 #define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0a, struct gpiohandle_config)
150 * struct gpiohandle_data - Information of values on a GPIO handle
151 * @values: when getting the state of lines this contains the current
152 * state of a line, when setting the state of lines these should contain
153 * the desired target state
155 struct gpiohandle_data {
156 __u8 values[GPIOHANDLES_MAX];
159 #define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
160 #define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)
162 /* Eventrequest flags */
163 #define GPIOEVENT_REQUEST_RISING_EDGE (1UL << 0)
164 #define GPIOEVENT_REQUEST_FALLING_EDGE (1UL << 1)
165 #define GPIOEVENT_REQUEST_BOTH_EDGES ((1UL << 0) | (1UL << 1))
168 * struct gpioevent_request - Information about a GPIO event request
169 * @lineoffset: the desired line to subscribe to events from, specified by
170 * offset index for the associated GPIO device
171 * @handleflags: desired handle flags for the desired GPIO line, such as
172 * GPIOHANDLE_REQUEST_ACTIVE_LOW or GPIOHANDLE_REQUEST_OPEN_DRAIN
173 * @eventflags: desired flags for the desired GPIO event line, such as
174 * GPIOEVENT_REQUEST_RISING_EDGE or GPIOEVENT_REQUEST_FALLING_EDGE
175 * @consumer_label: a desired consumer label for the selected GPIO line(s)
176 * such as "my-listener"
177 * @fd: if successful this field will contain a valid anonymous file handle
178 * after a GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value
181 struct gpioevent_request {
185 char consumer_label[32];
192 #define GPIOEVENT_EVENT_RISING_EDGE 0x01
193 #define GPIOEVENT_EVENT_FALLING_EDGE 0x02
196 * struct gpioevent_data - The actual event being pushed to userspace
197 * @timestamp: best estimate of time of event occurrence, in nanoseconds
198 * @id: event identifier
200 struct gpioevent_data {
205 #define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info)
206 #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info)
207 #define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0b, struct gpioline_info)
208 #define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0c, __u32)
209 #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request)
210 #define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request)
212 #endif /* _UAPI_GPIO_H_ */