include/uapi/linux/gpio.h

   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  */
  23 struct 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  */
  48 struct 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  */
  87 struct 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  */
 102 struct 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  */
 128 struct 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  */
 147 struct 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_ */