1/* 2 * <linux/gpio.h> - userspace ABI for the GPIO character devices 3 * 4 * Copyright (C) 2016 Linus Walleij 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 */ 10#ifndef _UAPI_GPIO_H_ 11#define _UAPI_GPIO_H_ 12 13#include <linux/ioctl.h> 14#include <linux/types.h> 15 16/** 17 * struct gpiochip_info - Information about a certain GPIO chip 18 * @name: the Linux kernel name of this GPIO chip 19 * @label: a functional name for this GPIO chip, such as a product 20 * number, may be NULL 21 * @lines: number of GPIO lines on this chip 22 */ 23struct gpiochip_info { 24 char name[32]; 25 char label[32]; 26 __u32 lines; 27}; 28 29/* Informational flags */ 30#define GPIOLINE_FLAG_KERNEL (1UL << 0) /* Line used by the kernel */ 31#define GPIOLINE_FLAG_IS_OUT (1UL << 1) 32#define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2) 33#define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3) 34#define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4) 35 36/** 37 * struct gpioline_info - Information about a certain GPIO line 38 * @line_offset: the local offset on this GPIO device, fill this in when 39 * requesting the line information from the kernel 40 * @flags: various flags for this line 41 * @name: the name of this GPIO line, such as the output pin of the line on the 42 * chip, a rail or a pin header name on a board, as specified by the gpio 43 * chip, may be NULL 44 * @consumer: a functional name for the consumer of this GPIO line as set by 45 * whatever is using it, will be NULL if there is no current user but may 46 * also be NULL if the consumer doesn't set this up 47 */ 48struct gpioline_info { 49 __u32 line_offset; 50 __u32 flags; 51 char name[32]; 52 char consumer[32]; 53}; 54 55/* Maximum number of requested handles */ 56#define GPIOHANDLES_MAX 64 57 58/* Linerequest flags */ 59#define GPIOHANDLE_REQUEST_INPUT (1UL << 0) 60#define GPIOHANDLE_REQUEST_OUTPUT (1UL << 1) 61#define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2) 62#define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3) 63#define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4) 64 65/** 66 * struct gpiohandle_request - Information about a GPIO handle request 67 * @lineoffsets: an array desired lines, specified by offset index for the 68 * associated GPIO device 69 * @flags: desired flags for the desired GPIO lines, such as 70 * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed 71 * together. Note that even if multiple lines are requested, the same flags 72 * must be applicable to all of them, if you want lines with individual 73 * flags set, request them one by one. It is possible to select 74 * a batch of input or output lines, but they must all have the same 75 * characteristics, i.e. all inputs or all outputs, all active low etc 76 * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set for a requested 77 * line, this specifies the default output value, should be 0 (low) or 78 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high) 79 * @consumer_label: a desired consumer label for the selected GPIO line(s) 80 * such as "my-bitbanged-relay" 81 * @lines: number of lines requested in this request, i.e. the number of 82 * valid fields in the above arrays, set to 1 to request a single line 83 * @fd: if successful this field will contain a valid anonymous file handle 84 * after a GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value 85 * means error 86 */ 87struct gpiohandle_request { 88 __u32 lineoffsets[GPIOHANDLES_MAX]; 89 __u32 flags; 90 __u8 default_values[GPIOHANDLES_MAX]; 91 char consumer_label[32]; 92 __u32 lines; 93 int fd; 94}; 95 96/** 97 * struct gpiohandle_data - Information of values on a GPIO handle 98 * @values: when getting the state of lines this contains the current 99 * state of a line, when setting the state of lines these should contain 100 * the desired target state 101 */ 102struct gpiohandle_data { 103 __u8 values[GPIOHANDLES_MAX]; 104}; 105 106#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data) 107#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data) 108 109/* Eventrequest flags */ 110#define GPIOEVENT_REQUEST_RISING_EDGE (1UL << 0) 111#define GPIOEVENT_REQUEST_FALLING_EDGE (1UL << 1) 112#define GPIOEVENT_REQUEST_BOTH_EDGES ((1UL << 0) | (1UL << 1)) 113 114/** 115 * struct gpioevent_request - Information about a GPIO event request 116 * @lineoffset: the desired line to subscribe to events from, specified by 117 * offset index for the associated GPIO device 118 * @handleflags: desired handle flags for the desired GPIO line, such as 119 * GPIOHANDLE_REQUEST_ACTIVE_LOW or GPIOHANDLE_REQUEST_OPEN_DRAIN 120 * @eventflags: desired flags for the desired GPIO event line, such as 121 * GPIOEVENT_REQUEST_RISING_EDGE or GPIOEVENT_REQUEST_FALLING_EDGE 122 * @consumer_label: a desired consumer label for the selected GPIO line(s) 123 * such as "my-listener" 124 * @fd: if successful this field will contain a valid anonymous file handle 125 * after a GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value 126 * means error 127 */ 128struct gpioevent_request { 129 __u32 lineoffset; 130 __u32 handleflags; 131 __u32 eventflags; 132 char consumer_label[32]; 133 int fd; 134}; 135 136/** 137 * GPIO event types 138 */ 139#define GPIOEVENT_EVENT_RISING_EDGE 0x01 140#define GPIOEVENT_EVENT_FALLING_EDGE 0x02 141 142/** 143 * struct gpioevent_data - The actual event being pushed to userspace 144 * @timestamp: best estimate of time of event occurrence, in nanoseconds 145 * @id: event identifier 146 */ 147struct gpioevent_data { 148 __u64 timestamp; 149 __u32 id; 150}; 151 152#define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info) 153#define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info) 154#define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request) 155#define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request) 156 157#endif /* _UAPI_GPIO_H_ */ 158