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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_ */
158