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/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
69 enum gpio_v2_line_flag {
70 GPIO_V2_LINE_FLAG_USED = _BITULL(0),
71 GPIO_V2_LINE_FLAG_ACTIVE_LOW = _BITULL(1),
72 GPIO_V2_LINE_FLAG_INPUT = _BITULL(2),
73 GPIO_V2_LINE_FLAG_OUTPUT = _BITULL(3),
74 GPIO_V2_LINE_FLAG_EDGE_RISING = _BITULL(4),
75 GPIO_V2_LINE_FLAG_EDGE_FALLING = _BITULL(5),
76 GPIO_V2_LINE_FLAG_OPEN_DRAIN = _BITULL(6),
77 GPIO_V2_LINE_FLAG_OPEN_SOURCE = _BITULL(7),
78 GPIO_V2_LINE_FLAG_BIAS_PULL_UP = _BITULL(8),
79 GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN = _BITULL(9),
80 GPIO_V2_LINE_FLAG_BIAS_DISABLED = _BITULL(10),
84 * struct gpio_v2_line_values - Values of GPIO lines
85 * @bits: a bitmap containing the value of the lines, set to 1 for active
87 * @mask: a bitmap identifying the lines to get or set, with each bit
88 * number corresponding to the index into &struct
89 * gpio_v2_line_request.offsets.
91 struct gpio_v2_line_values {
97 * enum gpio_v2_line_attr_id - &struct gpio_v2_line_attribute.id values
98 * identifying which field of the attribute union is in use.
99 * @GPIO_V2_LINE_ATTR_ID_FLAGS: flags field is in use
100 * @GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES: values field is in use
101 * @GPIO_V2_LINE_ATTR_ID_DEBOUNCE: debounce_period_us field is in use
103 enum gpio_v2_line_attr_id {
104 GPIO_V2_LINE_ATTR_ID_FLAGS = 1,
105 GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES = 2,
106 GPIO_V2_LINE_ATTR_ID_DEBOUNCE = 3,
110 * struct gpio_v2_line_attribute - a configurable attribute of a line
111 * @id: attribute identifier with value from &enum gpio_v2_line_attr_id
112 * @padding: reserved for future use and must be zero filled
113 * @flags: if id is %GPIO_V2_LINE_ATTR_ID_FLAGS, the flags for the GPIO
114 * line, with values from &enum gpio_v2_line_flag, such as
115 * %GPIO_V2_LINE_FLAG_ACTIVE_LOW, %GPIO_V2_LINE_FLAG_OUTPUT etc, added
116 * together. This overrides the default flags contained in the &struct
117 * gpio_v2_line_config for the associated line.
118 * @values: if id is %GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES, a bitmap
119 * containing the values to which the lines will be set, with each bit
120 * number corresponding to the index into &struct
121 * gpio_v2_line_request.offsets.
122 * @debounce_period_us: if id is %GPIO_V2_LINE_ATTR_ID_DEBOUNCE, the
123 * desired debounce period, in microseconds
125 struct gpio_v2_line_attribute {
130 __aligned_u64 values;
131 __u32 debounce_period_us;
136 * struct gpio_v2_line_config_attribute - a configuration attribute
137 * associated with one or more of the requested lines.
138 * @attr: the configurable attribute
139 * @mask: a bitmap identifying the lines to which the attribute applies,
140 * with each bit number corresponding to the index into &struct
141 * gpio_v2_line_request.offsets.
143 struct gpio_v2_line_config_attribute {
144 struct gpio_v2_line_attribute attr;
149 * struct gpio_v2_line_config - Configuration for GPIO lines
150 * @flags: flags for the GPIO lines, with values from &enum
151 * gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
152 * %GPIO_V2_LINE_FLAG_OUTPUT etc, added together. This is the default for
153 * all requested lines but may be overridden for particular lines using
155 * @num_attrs: the number of attributes in @attrs
156 * @padding: reserved for future use and must be zero filled
157 * @attrs: the configuration attributes associated with the requested
158 * lines. Any attribute should only be associated with a particular line
159 * once. If an attribute is associated with a line multiple times then the
160 * first occurrence (i.e. lowest index) has precedence.
162 struct gpio_v2_line_config {
165 /* Pad to fill implicit padding and reserve space for future use. */
167 struct gpio_v2_line_config_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
171 * struct gpio_v2_line_request - Information about a request for GPIO lines
172 * @offsets: an array of desired lines, specified by offset index for the
173 * associated GPIO chip
174 * @consumer: a desired consumer label for the selected GPIO lines such as
175 * "my-bitbanged-relay"
176 * @config: requested configuration for the lines.
177 * @num_lines: number of lines requested in this request, i.e. the number
178 * of valid fields in the %GPIO_V2_LINES_MAX sized arrays, set to 1 to
179 * request a single line
180 * @event_buffer_size: a suggested minimum number of line events that the
181 * kernel should buffer. This is only relevant if edge detection is
182 * enabled in the configuration. Note that this is only a suggested value
183 * and the kernel may allocate a larger buffer or cap the size of the
184 * buffer. If this field is zero then the buffer size defaults to a minimum
185 * of @num_lines * 16.
186 * @padding: reserved for future use and must be zero filled
187 * @fd: if successful this field will contain a valid anonymous file handle
188 * after a %GPIO_GET_LINE_IOCTL operation, zero or negative value means
191 struct gpio_v2_line_request {
192 __u32 offsets[GPIO_V2_LINES_MAX];
193 char consumer[GPIO_MAX_NAME_SIZE];
194 struct gpio_v2_line_config config;
196 __u32 event_buffer_size;
197 /* Pad to fill implicit padding and reserve space for future use. */
203 * struct gpio_v2_line_info - Information about a certain GPIO line
204 * @name: the name of this GPIO line, such as the output pin of the line on
205 * the chip, a rail or a pin header name on a board, as specified by the
206 * GPIO chip, may be empty (i.e. name[0] == '\0')
207 * @consumer: a functional name for the consumer of this GPIO line as set
208 * by whatever is using it, will be empty if there is no current user but
209 * may also be empty if the consumer doesn't set this up
210 * @offset: the local offset on this GPIO chip, fill this in when
211 * requesting the line information from the kernel
212 * @num_attrs: the number of attributes in @attrs
213 * @flags: flags for the GPIO lines, with values from &enum
214 * gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
215 * %GPIO_V2_LINE_FLAG_OUTPUT etc, added together.
216 * @attrs: the configuration attributes associated with the line
217 * @padding: reserved for future use
219 struct gpio_v2_line_info {
220 char name[GPIO_MAX_NAME_SIZE];
221 char consumer[GPIO_MAX_NAME_SIZE];
225 struct gpio_v2_line_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
226 /* Space reserved for future use. */
231 * enum gpio_v2_line_changed_type - &struct gpio_v2_line_changed.event_type
233 * @GPIO_V2_LINE_CHANGED_REQUESTED: line has been requested
234 * @GPIO_V2_LINE_CHANGED_RELEASED: line has been released
235 * @GPIO_V2_LINE_CHANGED_CONFIG: line has been reconfigured
237 enum gpio_v2_line_changed_type {
238 GPIO_V2_LINE_CHANGED_REQUESTED = 1,
239 GPIO_V2_LINE_CHANGED_RELEASED = 2,
240 GPIO_V2_LINE_CHANGED_CONFIG = 3,
244 * struct gpio_v2_line_info_changed - Information about a change in status
246 * @info: updated line information
247 * @timestamp_ns: estimate of time of status change occurrence, in nanoseconds
248 * @event_type: the type of change with a value from &enum
249 * gpio_v2_line_changed_type
250 * @padding: reserved for future use
252 struct gpio_v2_line_info_changed {
253 struct gpio_v2_line_info info;
254 __aligned_u64 timestamp_ns;
256 /* Pad struct to 64-bit boundary and reserve space for future use. */
261 * enum gpio_v2_line_event_id - &struct gpio_v2_line_event.id values
262 * @GPIO_V2_LINE_EVENT_RISING_EDGE: event triggered by a rising edge
263 * @GPIO_V2_LINE_EVENT_FALLING_EDGE: event triggered by a falling edge
265 enum gpio_v2_line_event_id {
266 GPIO_V2_LINE_EVENT_RISING_EDGE = 1,
267 GPIO_V2_LINE_EVENT_FALLING_EDGE = 2,
271 * struct gpio_v2_line_event - The actual event being pushed to userspace
272 * @timestamp_ns: best estimate of time of event occurrence, in nanoseconds.
273 * The @timestamp_ns is read from %CLOCK_MONOTONIC and is intended to allow
274 * the accurate measurement of the time between events. It does not provide
275 * the wall-clock time.
276 * @id: event identifier with value from &enum gpio_v2_line_event_id
277 * @offset: the offset of the line that triggered the event
278 * @seqno: the sequence number for this event in the sequence of events for
279 * all the lines in this line request
280 * @line_seqno: the sequence number for this event in the sequence of
281 * events on this particular line
282 * @padding: reserved for future use
284 struct gpio_v2_line_event {
285 __aligned_u64 timestamp_ns;
290 /* Space reserved for future use. */
297 * This version of the ABI is deprecated.
298 * Use the latest version of the ABI, defined above, instead.
301 /* Informational flags */
302 #define GPIOLINE_FLAG_KERNEL (1UL << 0) /* Line used by the kernel */
303 #define GPIOLINE_FLAG_IS_OUT (1UL << 1)
304 #define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2)
305 #define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3)
306 #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4)
307 #define GPIOLINE_FLAG_BIAS_PULL_UP (1UL << 5)
308 #define GPIOLINE_FLAG_BIAS_PULL_DOWN (1UL << 6)
309 #define GPIOLINE_FLAG_BIAS_DISABLE (1UL << 7)
312 * struct gpioline_info - Information about a certain GPIO line
313 * @line_offset: the local offset on this GPIO device, fill this in when
314 * requesting the line information from the kernel
315 * @flags: various flags for this line
316 * @name: the name of this GPIO line, such as the output pin of the line on the
317 * chip, a rail or a pin header name on a board, as specified by the gpio
318 * chip, may be empty (i.e. name[0] == '\0')
319 * @consumer: a functional name for the consumer of this GPIO line as set by
320 * whatever is using it, will be empty if there is no current user but may
321 * also be empty if the consumer doesn't set this up
323 * Note: This struct is part of ABI v1 and is deprecated.
324 * Use &struct gpio_v2_line_info instead.
326 struct gpioline_info {
329 char name[GPIO_MAX_NAME_SIZE];
330 char consumer[GPIO_MAX_NAME_SIZE];
333 /* Maximum number of requested handles */
334 #define GPIOHANDLES_MAX 64
336 /* Possible line status change events */
338 GPIOLINE_CHANGED_REQUESTED = 1,
339 GPIOLINE_CHANGED_RELEASED,
340 GPIOLINE_CHANGED_CONFIG,
344 * struct gpioline_info_changed - Information about a change in status
346 * @info: updated line information
347 * @timestamp: estimate of time of status change occurrence, in nanoseconds
348 * @event_type: one of %GPIOLINE_CHANGED_REQUESTED,
349 * %GPIOLINE_CHANGED_RELEASED and %GPIOLINE_CHANGED_CONFIG
350 * @padding: reserved for future use
352 * The &struct gpioline_info embedded here has 32-bit alignment on its own,
353 * but it works fine with 64-bit alignment too. With its 72 byte size, we can
354 * guarantee there are no implicit holes between it and subsequent members.
355 * The 20-byte padding at the end makes sure we don't add any implicit padding
356 * at the end of the structure on 64-bit architectures.
358 * Note: This struct is part of ABI v1 and is deprecated.
359 * Use &struct gpio_v2_line_info_changed instead.
361 struct gpioline_info_changed {
362 struct gpioline_info info;
365 __u32 padding[5]; /* for future use */
368 /* Linerequest flags */
369 #define GPIOHANDLE_REQUEST_INPUT (1UL << 0)
370 #define GPIOHANDLE_REQUEST_OUTPUT (1UL << 1)
371 #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2)
372 #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3)
373 #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4)
374 #define GPIOHANDLE_REQUEST_BIAS_PULL_UP (1UL << 5)
375 #define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6)
376 #define GPIOHANDLE_REQUEST_BIAS_DISABLE (1UL << 7)
379 * struct gpiohandle_request - Information about a GPIO handle request
380 * @lineoffsets: an array of desired lines, specified by offset index for the
381 * associated GPIO device
382 * @flags: desired flags for the desired GPIO lines, such as
383 * %GPIOHANDLE_REQUEST_OUTPUT, %GPIOHANDLE_REQUEST_ACTIVE_LOW etc, added
384 * together. Note that even if multiple lines are requested, the same flags
385 * must be applicable to all of them, if you want lines with individual
386 * flags set, request them one by one. It is possible to select
387 * a batch of input or output lines, but they must all have the same
388 * characteristics, i.e. all inputs or all outputs, all active low etc
389 * @default_values: if the %GPIOHANDLE_REQUEST_OUTPUT is set for a requested
390 * line, this specifies the default output value, should be 0 (low) or
391 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
392 * @consumer_label: a desired consumer label for the selected GPIO line(s)
393 * such as "my-bitbanged-relay"
394 * @lines: number of lines requested in this request, i.e. the number of
395 * valid fields in the above arrays, set to 1 to request a single line
396 * @fd: if successful this field will contain a valid anonymous file handle
397 * after a %GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value
400 * Note: This struct is part of ABI v1 and is deprecated.
401 * Use &struct gpio_v2_line_request instead.
403 struct gpiohandle_request {
404 __u32 lineoffsets[GPIOHANDLES_MAX];
406 __u8 default_values[GPIOHANDLES_MAX];
407 char consumer_label[GPIO_MAX_NAME_SIZE];
413 * struct gpiohandle_config - Configuration for a GPIO handle request
414 * @flags: updated flags for the requested GPIO lines, such as
415 * %GPIOHANDLE_REQUEST_OUTPUT, %GPIOHANDLE_REQUEST_ACTIVE_LOW etc, added
417 * @default_values: if the %GPIOHANDLE_REQUEST_OUTPUT is set in flags,
418 * this specifies the default output value, should be 0 (low) or
419 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high)
420 * @padding: reserved for future use and should be zero filled
422 * Note: This struct is part of ABI v1 and is deprecated.
423 * Use &struct gpio_v2_line_config instead.
425 struct gpiohandle_config {
427 __u8 default_values[GPIOHANDLES_MAX];
428 __u32 padding[4]; /* padding for future use */
432 * struct gpiohandle_data - Information of values on a GPIO handle
433 * @values: when getting the state of lines this contains the current
434 * state of a line, when setting the state of lines these should contain
435 * the desired target state
437 * Note: This struct is part of ABI v1 and is deprecated.
438 * Use &struct gpio_v2_line_values instead.
440 struct gpiohandle_data {
441 __u8 values[GPIOHANDLES_MAX];
444 /* Eventrequest flags */
445 #define GPIOEVENT_REQUEST_RISING_EDGE (1UL << 0)
446 #define GPIOEVENT_REQUEST_FALLING_EDGE (1UL << 1)
447 #define GPIOEVENT_REQUEST_BOTH_EDGES ((1UL << 0) | (1UL << 1))
450 * struct gpioevent_request - Information about a GPIO event request
451 * @lineoffset: the desired line to subscribe to events from, specified by
452 * offset index for the associated GPIO device
453 * @handleflags: desired handle flags for the desired GPIO line, such as
454 * %GPIOHANDLE_REQUEST_ACTIVE_LOW or %GPIOHANDLE_REQUEST_OPEN_DRAIN
455 * @eventflags: desired flags for the desired GPIO event line, such as
456 * %GPIOEVENT_REQUEST_RISING_EDGE or %GPIOEVENT_REQUEST_FALLING_EDGE
457 * @consumer_label: a desired consumer label for the selected GPIO line(s)
458 * such as "my-listener"
459 * @fd: if successful this field will contain a valid anonymous file handle
460 * after a %GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value
463 * Note: This struct is part of ABI v1 and is deprecated.
464 * Use &struct gpio_v2_line_request instead.
466 struct gpioevent_request {
470 char consumer_label[GPIO_MAX_NAME_SIZE];
477 #define GPIOEVENT_EVENT_RISING_EDGE 0x01
478 #define GPIOEVENT_EVENT_FALLING_EDGE 0x02
481 * struct gpioevent_data - The actual event being pushed to userspace
482 * @timestamp: best estimate of time of event occurrence, in nanoseconds
483 * @id: event identifier
485 * Note: This struct is part of ABI v1 and is deprecated.
486 * Use &struct gpio_v2_line_event instead.
488 struct gpioevent_data {
496 #define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info)
497 #define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0C, __u32)
502 #define GPIO_V2_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x05, struct gpio_v2_line_info)
503 #define GPIO_V2_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x06, struct gpio_v2_line_info)
504 #define GPIO_V2_GET_LINE_IOCTL _IOWR(0xB4, 0x07, struct gpio_v2_line_request)
505 #define GPIO_V2_LINE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0D, struct gpio_v2_line_config)
506 #define GPIO_V2_LINE_GET_VALUES_IOCTL _IOWR(0xB4, 0x0E, struct gpio_v2_line_values)
507 #define GPIO_V2_LINE_SET_VALUES_IOCTL _IOWR(0xB4, 0x0F, struct gpio_v2_line_values)
512 * These ioctl()s are deprecated. Use the v2 equivalent instead.
514 #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info)
515 #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request)
516 #define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request)
517 #define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
518 #define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)
519 #define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0A, struct gpiohandle_config)
520 #define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0B, struct gpioline_info)
522 #endif /* _UAPI_GPIO_H_ */