gpio.h
/* SPDX-License-Identifier: GPL-2.0-only 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/const.h>
#include <linux/ioctl.h>
#include <linux/types.h>
/*
* The maximum size of name and label arrays.
*
* Must be a multiple of 8 to ensure 32/64-bit alignment of structs.
*/
#define GPIO_MAX_NAME_SIZE 32
/**
* 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 (i.e. label[0] == '\0')
* @lines: number of GPIO lines on this chip
*/
struct gpiochip_info {
char name[GPIO_MAX_NAME_SIZE];
char label[GPIO_MAX_NAME_SIZE];
__u32 lines;
};
/*
* Maximum number of requested lines.
*
* Must be no greater than 64, as bitmaps are restricted here to 64-bits
* for simplicity, and a multiple of 2 to ensure 32/64-bit alignment of
* structs.
*/
#define GPIO_V2_LINES_MAX 64
/*
* The maximum number of configuration attributes associated with a line
* request.
*/
#define GPIO_V2_LINE_NUM_ATTRS_MAX 10
/**
* enum gpio_v2_line_flag - &struct gpio_v2_line_attribute.flags values
* @GPIO_V2_LINE_FLAG_USED: line is not available for request
* @GPIO_V2_LINE_FLAG_ACTIVE_LOW: line active state is physical low
* @GPIO_V2_LINE_FLAG_INPUT: line is an input
* @GPIO_V2_LINE_FLAG_OUTPUT: line is an output
* @GPIO_V2_LINE_FLAG_EDGE_RISING: line detects rising (inactive to active)
* edges
* @GPIO_V2_LINE_FLAG_EDGE_FALLING: line detects falling (active to
* inactive) edges
* @GPIO_V2_LINE_FLAG_OPEN_DRAIN: line is an open drain output
* @GPIO_V2_LINE_FLAG_OPEN_SOURCE: line is an open source output
* @GPIO_V2_LINE_FLAG_BIAS_PULL_UP: line has pull-up bias enabled
* @GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN: line has pull-down bias enabled
* @GPIO_V2_LINE_FLAG_BIAS_DISABLED: line has bias disabled
* @GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME: line events contain REALTIME timestamps
*/
enum gpio_v2_line_flag {
GPIO_V2_LINE_FLAG_USED = _BITULL(0),
GPIO_V2_LINE_FLAG_ACTIVE_LOW = _BITULL(1),
GPIO_V2_LINE_FLAG_INPUT = _BITULL(2),
GPIO_V2_LINE_FLAG_OUTPUT = _BITULL(3),
GPIO_V2_LINE_FLAG_EDGE_RISING = _BITULL(4),
GPIO_V2_LINE_FLAG_EDGE_FALLING = _BITULL(5),
GPIO_V2_LINE_FLAG_OPEN_DRAIN = _BITULL(6),
GPIO_V2_LINE_FLAG_OPEN_SOURCE = _BITULL(7),
GPIO_V2_LINE_FLAG_BIAS_PULL_UP = _BITULL(8),
GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN = _BITULL(9),
GPIO_V2_LINE_FLAG_BIAS_DISABLED = _BITULL(10),
GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME = _BITULL(11),
};
/**
* struct gpio_v2_line_values - Values of GPIO lines
* @bits: a bitmap containing the value of the lines, set to 1 for active
* and 0 for inactive.
* @mask: a bitmap identifying the lines to get or set, with each bit
* number corresponding to the index into &struct
* gpio_v2_line_request.offsets.
*/
struct gpio_v2_line_values {
__aligned_u64 bits;
__aligned_u64 mask;
};
/**
* enum gpio_v2_line_attr_id - &struct gpio_v2_line_attribute.id values
* identifying which field of the attribute union is in use.
* @GPIO_V2_LINE_ATTR_ID_FLAGS: flags field is in use
* @GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES: values field is in use
* @GPIO_V2_LINE_ATTR_ID_DEBOUNCE: debounce_period_us field is in use
*/
enum gpio_v2_line_attr_id {
GPIO_V2_LINE_ATTR_ID_FLAGS = 1,
GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES = 2,
GPIO_V2_LINE_ATTR_ID_DEBOUNCE = 3,
};
/**
* struct gpio_v2_line_attribute - a configurable attribute of a line
* @id: attribute identifier with value from &enum gpio_v2_line_attr_id
* @padding: reserved for future use and must be zero filled
* @flags: if id is %GPIO_V2_LINE_ATTR_ID_FLAGS, the flags for the GPIO
* line, with values from &enum gpio_v2_line_flag, such as
* %GPIO_V2_LINE_FLAG_ACTIVE_LOW, %GPIO_V2_LINE_FLAG_OUTPUT etc, added
* together. This overrides the default flags contained in the &struct
* gpio_v2_line_config for the associated line.
* @values: if id is %GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES, a bitmap
* containing the values to which the lines will be set, with each bit
* number corresponding to the index into &struct
* gpio_v2_line_request.offsets.
* @debounce_period_us: if id is %GPIO_V2_LINE_ATTR_ID_DEBOUNCE, the
* desired debounce period, in microseconds
*/
struct gpio_v2_line_attribute {
__u32 id;
__u32 padding;
union {
__aligned_u64 flags;
__aligned_u64 values;
__u32 debounce_period_us;
};
};
/**
* struct gpio_v2_line_config_attribute - a configuration attribute
* associated with one or more of the requested lines.
* @attr: the configurable attribute
* @mask: a bitmap identifying the lines to which the attribute applies,
* with each bit number corresponding to the index into &struct
* gpio_v2_line_request.offsets.
*/
struct gpio_v2_line_config_attribute {
struct gpio_v2_line_attribute attr;
__aligned_u64 mask;
};
/**
* struct gpio_v2_line_config - Configuration for GPIO lines
* @flags: flags for the GPIO lines, with values from &enum
* gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
* %GPIO_V2_LINE_FLAG_OUTPUT etc, added together. This is the default for
* all requested lines but may be overridden for particular lines using
* @attrs.
* @num_attrs: the number of attributes in @attrs
* @padding: reserved for future use and must be zero filled
* @attrs: the configuration attributes associated with the requested
* lines. Any attribute should only be associated with a particular line
* once. If an attribute is associated with a line multiple times then the
* first occurrence (i.e. lowest index) has precedence.
*/
struct gpio_v2_line_config {
__aligned_u64 flags;
__u32 num_attrs;
/* Pad to fill implicit padding and reserve space for future use. */
__u32 padding[5];
struct gpio_v2_line_config_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
};
/**
* struct gpio_v2_line_request - Information about a request for GPIO lines
* @offsets: an array of desired lines, specified by offset index for the
* associated GPIO chip
* @consumer: a desired consumer label for the selected GPIO lines such as
* "my-bitbanged-relay"
* @config: requested configuration for the lines.
* @num_lines: number of lines requested in this request, i.e. the number
* of valid fields in the %GPIO_V2_LINES_MAX sized arrays, set to 1 to
* request a single line
* @event_buffer_size: a suggested minimum number of line events that the
* kernel should buffer. This is only relevant if edge detection is
* enabled in the configuration. Note that this is only a suggested value
* and the kernel may allocate a larger buffer or cap the size of the
* buffer. If this field is zero then the buffer size defaults to a minimum
* of @num_lines * 16.
* @padding: reserved for future use and must be zero filled
* @fd: if successful this field will contain a valid anonymous file handle
* after a %GPIO_GET_LINE_IOCTL operation, zero or negative value means
* error
*/
struct gpio_v2_line_request {
__u32 offsets[GPIO_V2_LINES_MAX];
char consumer[GPIO_MAX_NAME_SIZE];
struct gpio_v2_line_config config;
__u32 num_lines;
__u32 event_buffer_size;
/* Pad to fill implicit padding and reserve space for future use. */
__u32 padding[5];
__s32 fd;
};
/**
* struct gpio_v2_line_info - Information about a certain GPIO 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 (i.e. name[0] == '\0')
* @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
* @offset: the local offset on this GPIO chip, fill this in when
* requesting the line information from the kernel
* @num_attrs: the number of attributes in @attrs
* @flags: flags for this GPIO line, with values from &enum
* gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
* %GPIO_V2_LINE_FLAG_OUTPUT etc, added together.
* @attrs: the configuration attributes associated with the line
* @padding: reserved for future use
*/
struct gpio_v2_line_info {
char name[GPIO_MAX_NAME_SIZE];
char consumer[GPIO_MAX_NAME_SIZE];
__u32 offset;
__u32 num_attrs;
__aligned_u64 flags;
struct gpio_v2_line_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX];
/* Space reserved for future use. */
__u32 padding[4];
};
/**
* enum gpio_v2_line_changed_type - &struct gpio_v2_line_changed.event_type
* values
* @GPIO_V2_LINE_CHANGED_REQUESTED: line has been requested
* @GPIO_V2_LINE_CHANGED_RELEASED: line has been released
* @GPIO_V2_LINE_CHANGED_CONFIG: line has been reconfigured
*/
enum gpio_v2_line_changed_type {
GPIO_V2_LINE_CHANGED_REQUESTED = 1,
GPIO_V2_LINE_CHANGED_RELEASED = 2,
GPIO_V2_LINE_CHANGED_CONFIG = 3,
};
/**
* struct gpio_v2_line_info_changed - Information about a change in status
* of a GPIO line
* @info: updated line information
* @timestamp_ns: estimate of time of status change occurrence, in nanoseconds
* @event_type: the type of change with a value from &enum
* gpio_v2_line_changed_type
* @padding: reserved for future use
*/
struct gpio_v2_line_info_changed {
struct gpio_v2_line_info info;
__aligned_u64 timestamp_ns;
__u32 event_type;
/* Pad struct to 64-bit boundary and reserve space for future use. */
__u32 padding[5];
};
/**
* enum gpio_v2_line_event_id - &struct gpio_v2_line_event.id values
* @GPIO_V2_LINE_EVENT_RISING_EDGE: event triggered by a rising edge
* @GPIO_V2_LINE_EVENT_FALLING_EDGE: event triggered by a falling edge
*/
enum gpio_v2_line_event_id {
GPIO_V2_LINE_EVENT_RISING_EDGE = 1,
GPIO_V2_LINE_EVENT_FALLING_EDGE = 2,
};
/**
* struct gpio_v2_line_event - The actual event being pushed to userspace
* @timestamp_ns: best estimate of time of event occurrence, in nanoseconds.
* @id: event identifier with value from &enum gpio_v2_line_event_id
* @offset: the offset of the line that triggered the event
* @seqno: the sequence number for this event in the sequence of events for
* all the lines in this line request
* @line_seqno: the sequence number for this event in the sequence of
* events on this particular line
* @padding: reserved for future use
*
* By default the @timestamp_ns is read from %CLOCK_MONOTONIC and is
* intended to allow the accurate measurement of the time between events.
* It does not provide the wall-clock time.
*
* If the %GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME flag is set then the
* @timestamp_ns is read from %CLOCK_REALTIME.
*/
struct gpio_v2_line_event {
__aligned_u64 timestamp_ns;
__u32 id;
__u32 offset;
__u32 seqno;
__u32 line_seqno;
/* Space reserved for future use. */
__u32 padding[6];
};
/*
* ABI v1
*
* This version of the ABI is deprecated.
* Use the latest version of the ABI, defined above, instead.
*/
/* 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 (i.e. name[0] == '\0')
* @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
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_info instead.
*/
struct gpioline_info {
__u32 line_offset;
__u32 flags;
char name[GPIO_MAX_NAME_SIZE];
char consumer[GPIO_MAX_NAME_SIZE];
};
/* 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
* @event_type: one of %GPIOLINE_CHANGED_REQUESTED,
* %GPIOLINE_CHANGED_RELEASED and %GPIOLINE_CHANGED_CONFIG
* @padding: reserved for future use
*
* The &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.
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_info_changed instead.
*/
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, added
* 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
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_request instead.
*/
struct gpiohandle_request {
__u32 lineoffsets[GPIOHANDLES_MAX];
__u32 flags;
__u8 default_values[GPIOHANDLES_MAX];
char consumer_label[GPIO_MAX_NAME_SIZE];
__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, added
* 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
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_config instead.
*/
struct gpiohandle_config {
__u32 flags;
__u8 default_values[GPIOHANDLES_MAX];
__u32 padding[4]; /* padding for future use */
};
/**
* 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
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_values instead.
*/
struct gpiohandle_data {
__u8 values[GPIOHANDLES_MAX];
};
/* 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
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_request instead.
*/
struct gpioevent_request {
__u32 lineoffset;
__u32 handleflags;
__u32 eventflags;
char consumer_label[GPIO_MAX_NAME_SIZE];
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
*
* Note: This struct is part of ABI v1 and is deprecated.
* Use &struct gpio_v2_line_event instead.
*/
struct gpioevent_data {
__u64 timestamp;
__u32 id;
};
/*
* v1 and v2 ioctl()s
*/
#define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info)
#define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0C, __u32)
/*
* v2 ioctl()s
*/
#define GPIO_V2_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x05, struct gpio_v2_line_info)
#define GPIO_V2_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x06, struct gpio_v2_line_info)
#define GPIO_V2_GET_LINE_IOCTL _IOWR(0xB4, 0x07, struct gpio_v2_line_request)
#define GPIO_V2_LINE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0D, struct gpio_v2_line_config)
#define GPIO_V2_LINE_GET_VALUES_IOCTL _IOWR(0xB4, 0x0E, struct gpio_v2_line_values)
#define GPIO_V2_LINE_SET_VALUES_IOCTL _IOWR(0xB4, 0x0F, struct gpio_v2_line_values)
/*
* v1 ioctl()s
*
* These ioctl()s are deprecated. Use the v2 equivalent instead.
*/
#define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info)
#define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request)
#define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request)
#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data)
#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data)
#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0A, struct gpiohandle_config)
#define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0B, struct gpioline_info)
#endif /* _UAPI_GPIO_H_ */