1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 /* 3 * <linux/gpio.h> - userspace ABI for the GPIO character devices 4 * 5 * Copyright (C) 2016 Linus Walleij 6 * 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. 10 */ 11 #ifndef _UAPI_GPIO_H_ 12 #define _UAPI_GPIO_H_ 13 14 #include <linux/ioctl.h> 15 #include <linux/types.h> 16 17 /** 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 NULL 22 * @lines: number of GPIO lines on this chip 23 */ 24 struct gpiochip_info { 25 char name[32]; 26 char label[32]; 27 __u32 lines; 28 }; 29 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 37 /** 38 * struct gpioline_info - Information about a certain GPIO line 39 * @line_offset: the local offset on this GPIO device, fill this in when 40 * requesting the line information from the kernel 41 * @flags: various flags for this line 42 * @name: the name of this GPIO line, such as the output pin of the line on the 43 * chip, a rail or a pin header name on a board, as specified by the gpio 44 * chip, may be NULL 45 * @consumer: a functional name for the consumer of this GPIO line as set by 46 * whatever is using it, will be NULL if there is no current user but may 47 * also be NULL if the consumer doesn't set this up 48 */ 49 struct gpioline_info { 50 __u32 line_offset; 51 __u32 flags; 52 char name[32]; 53 char consumer[32]; 54 }; 55 56 /* Maximum number of requested handles */ 57 #define GPIOHANDLES_MAX 64 58 59 /* Linerequest flags */ 60 #define GPIOHANDLE_REQUEST_INPUT (1UL << 0) 61 #define GPIOHANDLE_REQUEST_OUTPUT (1UL << 1) 62 #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2) 63 #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3) 64 #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4) 65 66 /** 67 * struct gpiohandle_request - Information about a GPIO handle request 68 * @lineoffsets: an array desired lines, specified by offset index for the 69 * associated GPIO device 70 * @flags: desired flags for the desired GPIO lines, such as 71 * GPIOHANDLE_REQUEST_OUTPUT, GPIOHANDLE_REQUEST_ACTIVE_LOW etc, OR:ed 72 * together. Note that even if multiple lines are requested, the same flags 73 * must be applicable to all of them, if you want lines with individual 74 * flags set, request them one by one. It is possible to select 75 * a batch of input or output lines, but they must all have the same 76 * characteristics, i.e. all inputs or all outputs, all active low etc 77 * @default_values: if the GPIOHANDLE_REQUEST_OUTPUT is set for a requested 78 * line, this specifies the default output value, should be 0 (low) or 79 * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high) 80 * @consumer_label: a desired consumer label for the selected GPIO line(s) 81 * such as "my-bitbanged-relay" 82 * @lines: number of lines requested in this request, i.e. the number of 83 * valid fields in the above arrays, set to 1 to request a single line 84 * @fd: if successful this field will contain a valid anonymous file handle 85 * after a GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value 86 * means error 87 */ 88 struct gpiohandle_request { 89 __u32 lineoffsets[GPIOHANDLES_MAX]; 90 __u32 flags; 91 __u8 default_values[GPIOHANDLES_MAX]; 92 char consumer_label[32]; 93 __u32 lines; 94 int fd; 95 }; 96 97 /** 98 * struct gpiohandle_data - Information of values on a GPIO handle 99 * @values: when getting the state of lines this contains the current 100 * state of a line, when setting the state of lines these should contain 101 * the desired target state 102 */ 103 struct gpiohandle_data { 104 __u8 values[GPIOHANDLES_MAX]; 105 }; 106 107 #define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data) 108 #define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data) 109 110 /* Eventrequest flags */ 111 #define GPIOEVENT_REQUEST_RISING_EDGE (1UL << 0) 112 #define GPIOEVENT_REQUEST_FALLING_EDGE (1UL << 1) 113 #define GPIOEVENT_REQUEST_BOTH_EDGES ((1UL << 0) | (1UL << 1)) 114 115 /** 116 * struct gpioevent_request - Information about a GPIO event request 117 * @lineoffset: the desired line to subscribe to events from, specified by 118 * offset index for the associated GPIO device 119 * @handleflags: desired handle flags for the desired GPIO line, such as 120 * GPIOHANDLE_REQUEST_ACTIVE_LOW or GPIOHANDLE_REQUEST_OPEN_DRAIN 121 * @eventflags: desired flags for the desired GPIO event line, such as 122 * GPIOEVENT_REQUEST_RISING_EDGE or GPIOEVENT_REQUEST_FALLING_EDGE 123 * @consumer_label: a desired consumer label for the selected GPIO line(s) 124 * such as "my-listener" 125 * @fd: if successful this field will contain a valid anonymous file handle 126 * after a GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value 127 * means error 128 */ 129 struct gpioevent_request { 130 __u32 lineoffset; 131 __u32 handleflags; 132 __u32 eventflags; 133 char consumer_label[32]; 134 int fd; 135 }; 136 137 /** 138 * GPIO event types 139 */ 140 #define GPIOEVENT_EVENT_RISING_EDGE 0x01 141 #define GPIOEVENT_EVENT_FALLING_EDGE 0x02 142 143 /** 144 * struct gpioevent_data - The actual event being pushed to userspace 145 * @timestamp: best estimate of time of event occurrence, in nanoseconds 146 * @id: event identifier 147 */ 148 struct gpioevent_data { 149 __u64 timestamp; 150 __u32 id; 151 }; 152 153 #define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info) 154 #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info) 155 #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request) 156 #define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request) 157 158 #endif /* _UAPI_GPIO_H_ */ 159