1 /* SPDX-License-Identifier: GPL-2.0-only 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/const.h>
15 #include <linux/ioctl.h>
16 #include <linux/types.h>
19 * The maximum size of name and label arrays.
21 * Must be a multiple of 8 to ensure 32/64-bit alignment of structs.
23 #define GPIO_MAX_NAME_SIZE 32
26 * struct gpiochip_info - Information about a certain GPIO chip
27 * @name: the Linux kernel name of this GPIO chip
28 * @label: a functional name for this GPIO chip, such as a product
29 * number, may be empty (i.e. label[0] == '\0')
30 * @lines: number of GPIO lines on this chip
32 struct gpiochip_info {
33 char name[GPIO_MAX_NAME_SIZE];
34 char label[GPIO_MAX_NAME_SIZE];
39 * Maximum number of requested lines.
41 * Must be no greater than 64, as bitmaps are restricted here to 64-bits
42 * for simplicity, and a multiple of 2 to ensure 32/64-bit alignment of
45 #define GPIO_V2_LINES_MAX 64
48 * The maximum number of configuration attributes associated with a line
51 #define GPIO_V2_LINE_NUM_ATTRS_MAX 10
54 * enum gpio_v2_line_flag - &struct gpio_v2_line_attribute.flags values
55 * @GPIO_V2_LINE_FLAG_USED: line is not available for request
56 * @GPIO_V2_LINE_FLAG_ACTIVE_LOW: line active state is physical low
57 * @GPIO_V2_LINE_FLAG_INPUT: line is an input
58 * @GPIO_V2_LINE_FLAG_OUTPUT: line is an output
59 * @GPIO_V2_LINE_FLAG_EDGE_RISING: line detects rising (inactive to active)
61 * @GPIO_V2_LINE_FLAG_EDGE_FALLING: line detects falling (active to
63 * @GPIO_V2_LINE_FLAG_OPEN_DRAIN: line is an open drain output
64 * @GPIO_V2_LINE_FLAG_OPEN_SOURCE: line is an open source output
65 * @GPIO_V2_LINE_FLAG_BIAS_PULL_UP: line has pull-up bias enabled
66 * @GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN: line has pull-down bias enabled
67 * @GPIO_V2_LINE_FLAG_BIAS_DISABLED: line has bias disabled
68 * @GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME: line events contain REALTIME timestamps
70 enum gpio_v2_line_flag {
71 GPIO_V2_LINE_FLAG_USED = _BITULL(0),
72 GPIO_V2_LINE_FLAG_ACTIVE_LOW = _BITULL(1),
73 GPIO_V2_LINE_FLAG_INPUT = _BITULL(2),
74 GPIO_V2_LINE_FLAG_OUTPUT = _BITULL(3),
75 GPIO_V2_LINE_FLAG_EDGE_RISING = _BITULL(4),
76 GPIO_V2_LINE_FLAG_EDGE_FALLING = _BITULL(5),
77 GPIO_V2_LINE_FLAG_OPEN_DRAIN = _BITULL(6),
78 GPIO_V2_LINE_FLAG_OPEN_SOURCE = _BITULL(7),
79 GPIO_V2_LINE_FLAG_BIAS_PULL_UP = _BITULL(8),
80 GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN = _BITULL(9),
81 GPIO_V2_LINE_FLAG_BIAS_DISABLED = _BITULL(10),
82 GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME = _BITULL(11),
86 * struct gpio_v2_line_values - Values of GPIO lines
87 * @bits: a bitmap containing the value of the lines, set to 1 for active
89 * @mask: a bitmap identifying the lines to get or set, with each bit
90 * number corresponding to the index into &struct
91 * gpio_v2_line_request.offsets.
93 struct gpio_v2_line_values {
99 * enum gpio_v2_line_attr_id - &struct gpio_v2_line_attribute.id values
100 * identifying which field of the attribute union is in use.
101 * @GPIO_V2_LINE_ATTR_ID_FLAGS: flags field is in use
102 * @GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES: values field is in use
103 * @GPIO_V2_LINE_ATTR_ID_DEBOUNCE: debounce_period_us field is in use
105 enum gpio_v2_line_attr_id {
106 GPIO_V2_LINE_ATTR_ID_FLAGS = 1,
107 GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES = 2,
108 GPIO_V2_LINE_ATTR_ID_DEBOUNCE = 3,
112 * struct gpio_v2_line_attribute - a configurable attribute of a line
113 * @id: attribute identifier with value from &enum gpio_v2_line_attr_id
114 * @padding: reserved for future use and must be zero filled
115 * @flags: if id is %GPIO_V2_LINE_ATTR_ID_FLAGS, the flags for the GPIO
116 * line, with values from &enum gpio_v2_line_flag, such as
117 * %GPIO_V2_LINE_FLAG_ACTIVE_LOW, %GPIO_V2_LINE_FLAG_OUTPUT etc, added
118 * together. This overrides the default flags contained in the &struct
119 * gpio_v2_line_config for the associated line.
120 * @values: if id is %GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES, a bitmap
121 * containing the values to which the lines will be set, with each bit
122 * number corresponding to the index into &struct
123 * gpio_v2_line_request.offsets.
124 * @debounce_period_us: if id is %GPIO_V2_LINE_ATTR_ID_DEBOUNCE, the
125 * desired debounce period, in microseconds
127 struct gpio_v2_line_attribute {
132 __aligned_u64 values;
133 __u32 debounce_period_us;
138 * struct gpio_v2_line_config_attribute - a configuration attribute
139 * associated with one or more of the requested lines.
140 * @attr: the configurable attribute
141 * @mask: a bitmap identifying the lines to which the attribute applies,
142 * with each bit number corresponding to the index into &struct
143 * gpio_v2_line_request.offsets.
145 struct gpio_v2_line_config_attribute {
146 struct gpio_v2_line_attribute attr;
151 * struct gpio_v2_line_config - Configuration for GPIO lines
152 * @flags: flags for the GPIO lines, with values from &enum
153 * gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
154 * %GPIO_V2_LINE_FLAG_OUTPUT etc, added together. This is the default for
155 * all requested lines but may be overridden for particular lines using
157 * @num_attrs: the number of attributes in @attrs
158 * @padding: reserved for future use and must be zero filled
159 * @attrs: the configuration attributes associated with the requested
160 * lines. Any attribute should only be associated with a particular line
161 * once. If an attribute is associated with a line multiple times then the
162 * first occurrence (i.e. lowest index) has precedence.
164 struct gpio_v2_line_config {
167 /* Pad to fill implicit padding and reserve space for future use. */
169 struct gpio_v2_line_config_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
173 * struct gpio_v2_line_request - Information about a request for GPIO lines
174 * @offsets: an array of desired lines, specified by offset index for the
175 * associated GPIO chip
176 * @consumer: a desired consumer label for the selected GPIO lines such as
177 * "my-bitbanged-relay"
178 * @config: requested configuration for the lines.
179 * @num_lines: number of lines requested in this request, i.e. the number
180 * of valid fields in the %GPIO_V2_LINES_MAX sized arrays, set to 1 to
181 * request a single line
182 * @event_buffer_size: a suggested minimum number of line events that the
183 * kernel should buffer. This is only relevant if edge detection is
184 * enabled in the configuration. Note that this is only a suggested value
185 * and the kernel may allocate a larger buffer or cap the size of the
186 * buffer. If this field is zero then the buffer size defaults to a minimum
187 * of @num_lines * 16.
188 * @padding: reserved for future use and must be zero filled
189 * @fd: if successful this field will contain a valid anonymous file handle
190 * after a %GPIO_GET_LINE_IOCTL operation, zero or negative value means
193 struct gpio_v2_line_request {
194 __u32 offsets[GPIO_V2_LINES_MAX];
195 char consumer[GPIO_MAX_NAME_SIZE];
196 struct gpio_v2_line_config config;
198 __u32 event_buffer_size;
199 /* Pad to fill implicit padding and reserve space for future use. */
205 * struct gpio_v2_line_info - Information about a certain GPIO line
206 * @name: the name of this GPIO line, such as the output pin of the line on
207 * the chip, a rail or a pin header name on a board, as specified by the
208 * GPIO chip, may be empty (i.e. name[0] == '\0')
209 * @consumer: a functional name for the consumer of this GPIO line as set
210 * by whatever is using it, will be empty if there is no current user but
211 * may also be empty if the consumer doesn't set this up
212 * @offset: the local offset on this GPIO chip, fill this in when
213 * requesting the line information from the kernel
214 * @num_attrs: the number of attributes in @attrs
215 * @flags: flags for this GPIO line, with values from &enum
216 * gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
217 * %GPIO_V2_LINE_FLAG_OUTPUT etc, added together.
218 * @attrs: the configuration attributes associated with the line
219 * @padding: reserved for future use
221 struct gpio_v2_line_info {
222 char name[GPIO_MAX_NAME_SIZE];
223 char consumer[GPIO_MAX_NAME_SIZE];
227 struct gpio_v2_line_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
228 /* Space reserved for future use. */
233 * enum gpio_v2_line_changed_type - &struct gpio_v2_line_changed.event_type
235 * @GPIO_V2_LINE_CHANGED_REQUESTED: line has been requested
236 * @GPIO_V2_LINE_CHANGED_RELEASED: line has been released
237 * @GPIO_V2_LINE_CHANGED_CONFIG: line has been reconfigured
239 enum gpio_v2_line_changed_type {
240 GPIO_V2_LINE_CHANGED_REQUESTED = 1,
241 GPIO_V2_LINE_CHANGED_RELEASED = 2,
242 GPIO_V2_LINE_CHANGED_CONFIG = 3,
246 * struct gpio_v2_line_info_changed - Information about a change in status
248 * @info: updated line information
249 * @timestamp_ns: estimate of time of status change occurrence, in nanoseconds
250 * @event_type: the type of change with a value from &enum
251 * gpio_v2_line_changed_type
252 * @padding: reserved for future use
254 struct gpio_v2_line_info_changed {
255 struct gpio_v2_line_info info;
256 __aligned_u64 timestamp_ns;
258 /* Pad struct to 64-bit boundary and reserve space for future use. */
263 * enum gpio_v2_line_event_id - &struct gpio_v2_line_event.id values
264 * @GPIO_V2_LINE_EVENT_RISING_EDGE: event triggered by a rising edge
265 * @GPIO_V2_LINE_EVENT_FALLING_EDGE: event triggered by a falling edge
267 enum gpio_v2_line_event_id {
268 GPIO_V2_LINE_EVENT_RISING_EDGE = 1,
269 GPIO_V2_LINE_EVENT_FALLING_EDGE = 2,
273 * struct gpio_v2_line_event - The actual event being pushed to userspace
274 * @timestamp_ns: best estimate of time of event occurrence, in nanoseconds.
275 * @id: event identifier with value from &enum gpio_v2_line_event_id
276 * @offset: the offset of the line that triggered the event
277 * @seqno: the sequence number for this event in the sequence of events for
278 * all the lines in this line request
279 * @line_seqno: the sequence number for this event in the sequence of
280 * events on this particular line
281 * @padding: reserved for future use
283 * By default the @timestamp_ns is read from %CLOCK_MONOTONIC and is
284 * intended to allow the accurate measurement of the time between events.
285 * It does not provide the wall-clock time.
287 * If the %GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME flag is set then the
288 * @timestamp_ns is read from %CLOCK_REALTIME.
290 struct gpio_v2_line_event {
291 __aligned_u64 timestamp_ns;
296 /* Space reserved for future use. */
303 * This version of the ABI is deprecated.
304 * Use the latest version of the ABI, defined above, instead.
307 /* Informational flags */
308 #define GPIOLINE_FLAG_KERNEL (1UL << 0) /* Line used by the kernel */
309 #define GPIOLINE_FLAG_IS_OUT (1UL << 1)
310 #define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2)
311 #define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3)
312 #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4)
313 #define GPIOLINE_FLAG_BIAS_PULL_UP (1UL << 5)
314 #define GPIOLINE_FLAG_BIAS_PULL_DOWN (1UL << 6)
315 #define GPIOLINE_FLAG_BIAS_DISABLE (1UL << 7)
318 * struct gpioline_info - Information about a certain GPIO line
319 * @line_offset: the local offset on this GPIO device, fill this in when
320 * requesting the line information from the kernel
321 * @flags: various flags for this line
322 * @name: the name of this GPIO line, such as the output pin of the line on the
323 * chip, a rail or a pin header name on a board, as specified by the gpio
324 * chip, may be empty (i.e. name[0] == '\0')
325 * @consumer: a functional name for the consumer of this GPIO line as set by
326 * whatever is using it, will be empty if there is no current user but may
327 * also be empty if the consumer doesn't set this up
329 * Note: This struct is part of ABI v1 and is deprecated.
330 * Use &struct gpio_v2_line_info instead.
332 struct gpioline_info {
335 char name[GPIO_MAX_NAME_SIZE];
336 char consumer[GPIO_MAX_NAME_SIZE];
339 /* Maximum number of requested handles */
340 #define GPIOHANDLES_MAX 64
342 /* Possible line status change events */
344 GPIOLINE_CHANGED_REQUESTED = 1,
345 GPIOLINE_CHANGED_RELEASED,
346 GPIOLINE_CHANGED_CONFIG,
350 * struct gpioline_info_changed - Information about a change in status
352 * @info: updated line information
353 * @timestamp: estimate of time of status change occurrence, in nanoseconds
354 * @event_type: one of %GPIOLINE_CHANGED_REQUESTED,
355 * %GPIOLINE_CHANGED_RELEASED and %GPIOLINE_CHANGED_CONFIG
356 * @padding: reserved for future use
358 * The &struct gpioline_info embedded here has 32-bit alignment on its own,
359 * but it works fine with 64-bit alignment too. With its 72 byte size, we can
360 * guarantee there are no implicit holes between it and subsequent members.
361 * The 20-byte padding at the end makes sure we don't add any implicit padding
362 * at the end of the structure on 64-bit architectures.
364 * Note: This struct is part of ABI v1 and is deprecated.
365 * Use &struct gpio_v2_line_info_changed instead.
367 struct gpioline_info_changed {
368 struct gpioline_info info;
371 __u32 padding[5]; /* for future use */
374 /* Linerequest flags */
375 #define GPIOHANDLE_REQUEST_INPUT (1UL << 0)
376 #define GPIOHANDLE_REQUEST_OUTPUT (1UL << 1)
377 #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2)
378 #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3)
379 #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4)
380 #define GPIOHANDLE_REQUEST_BIAS_PULL_UP (1UL << 5)
381 #define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6)
382 #define GPIOHANDLE_REQUEST_BIAS_DISABLE (1UL << 7)
385 * struct gpiohandle_request - Information about a GPIO handle request
386 * @lineoffsets: an array of desired lines, specified by offset index for the
387 * associated GPIO device
388 * @flags: desired flags for the desired GPIO lines, such as
389 * %GPIOHANDLE_REQUEST_OUTPUT, %GPIOHANDLE_REQUEST_ACTIVE_LOW etc, added
390 * together. Note that even if multiple lines are requested, the same flags
391 * must be applicable to all of them, if you want lines with individual
392 * flags set, request them one by one. It is possible to select
393 * a batch of input or output lines, but they must all have the same
394 * characteristics, i.e. all inputs or all outputs, all active low etc
395 * @default_values: if the %GPIOHANDLE_REQUEST_OUTPUT is set for a requested
396 * line, this specifies the default output value, should be 0 (low) or
397 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
398 * @consumer_label: a desired consumer label for the selected GPIO line(s)
399 * such as "my-bitbanged-relay"
400 * @lines: number of lines requested in this request, i.e. the number of
401 * valid fields in the above arrays, set to 1 to request a single line
402 * @fd: if successful this field will contain a valid anonymous file handle
403 * after a %GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value
406 * Note: This struct is part of ABI v1 and is deprecated.
407 * Use &struct gpio_v2_line_request instead.
409 struct gpiohandle_request {
410 __u32 lineoffsets[GPIOHANDLES_MAX];
412 __u8 default_values[GPIOHANDLES_MAX];
413 char consumer_label[GPIO_MAX_NAME_SIZE];
419 * struct gpiohandle_config - Configuration for a GPIO handle request
420 * @flags: updated flags for the requested GPIO lines, such as
421 * %GPIOHANDLE_REQUEST_OUTPUT, %GPIOHANDLE_REQUEST_ACTIVE_LOW etc, added
423 * @default_values: if the %GPIOHANDLE_REQUEST_OUTPUT is set in flags,
424 * this specifies the default output value, should be 0 (low) or
425 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
426 * @padding: reserved for future use and should be zero filled
428 * Note: This struct is part of ABI v1 and is deprecated.
429 * Use &struct gpio_v2_line_config instead.
431 struct gpiohandle_config {
433 __u8 default_values[GPIOHANDLES_MAX];
434 __u32 padding[4]; /* padding for future use */
438 * struct gpiohandle_data - Information of values on a GPIO handle
439 * @values: when getting the state of lines this contains the current
440 * state of a line, when setting the state of lines these should contain
441 * the desired target state
443 * Note: This struct is part of ABI v1 and is deprecated.
444 * Use &struct gpio_v2_line_values instead.
446 struct gpiohandle_data {
447 __u8 values[GPIOHANDLES_MAX];
450 /* Eventrequest flags */
451 #define GPIOEVENT_REQUEST_RISING_EDGE (1UL << 0)
452 #define GPIOEVENT_REQUEST_FALLING_EDGE (1UL << 1)
453 #define GPIOEVENT_REQUEST_BOTH_EDGES ((1UL << 0) | (1UL << 1))
456 * struct gpioevent_request - Information about a GPIO event request
457 * @lineoffset: the desired line to subscribe to events from, specified by
458 * offset index for the associated GPIO device
459 * @handleflags: desired handle flags for the desired GPIO line, such as
460 * %GPIOHANDLE_REQUEST_ACTIVE_LOW or %GPIOHANDLE_REQUEST_OPEN_DRAIN
461 * @eventflags: desired flags for the desired GPIO event line, such as
462 * %GPIOEVENT_REQUEST_RISING_EDGE or %GPIOEVENT_REQUEST_FALLING_EDGE
463 * @consumer_label: a desired consumer label for the selected GPIO line(s)
464 * such as "my-listener"
465 * @fd: if successful this field will contain a valid anonymous file handle
466 * after a %GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value
469 * Note: This struct is part of ABI v1 and is deprecated.
470 * Use &struct gpio_v2_line_request instead.
472 struct gpioevent_request {
476 char consumer_label[GPIO_MAX_NAME_SIZE];
483 #define GPIOEVENT_EVENT_RISING_EDGE 0x01
484 #define GPIOEVENT_EVENT_FALLING_EDGE 0x02
487 * struct gpioevent_data - The actual event being pushed to userspace
488 * @timestamp: best estimate of time of event occurrence, in nanoseconds
489 * @id: event identifier
491 * Note: This struct is part of ABI v1 and is deprecated.
492 * Use &struct gpio_v2_line_event instead.
494 struct gpioevent_data {
502 #define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info)
503 #define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0C, __u32)
508 #define GPIO_V2_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x05, struct gpio_v2_line_info)
509 #define GPIO_V2_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x06, struct gpio_v2_line_info)
510 #define GPIO_V2_GET_LINE_IOCTL _IOWR(0xB4, 0x07, struct gpio_v2_line_request)
511 #define GPIO_V2_LINE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0D, struct gpio_v2_line_config)
512 #define GPIO_V2_LINE_GET_VALUES_IOCTL _IOWR(0xB4, 0x0E, struct gpio_v2_line_values)
513 #define GPIO_V2_LINE_SET_VALUES_IOCTL _IOWR(0xB4, 0x0F, struct gpio_v2_line_values)
518 * These ioctl()s are deprecated. Use the v2 equivalent instead.
520 #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info)
521 #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request)
522 #define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request)
523 #define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
524 #define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)
525 #define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0A, struct gpiohandle_config)
526 #define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0B, struct gpioline_info)
528 #endif /* _UAPI_GPIO_H_ */