1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * lsgpio - example on how to list the GPIO lines on a system |
4 | * |
5 | * Copyright (C) 2015 Linus Walleij |
6 | * |
7 | * Usage: |
8 | * lsgpio <-n device-name> |
9 | */ |
10 | |
11 | #include <unistd.h> |
12 | #include <stdlib.h> |
13 | #include <stdbool.h> |
14 | #include <stdio.h> |
15 | #include <dirent.h> |
16 | #include <errno.h> |
17 | #include <string.h> |
18 | #include <poll.h> |
19 | #include <fcntl.h> |
20 | #include <getopt.h> |
21 | #include <sys/ioctl.h> |
22 | #include <linux/gpio.h> |
23 | |
24 | #include "gpio-utils.h" |
25 | |
26 | struct gpio_flag { |
27 | char *name; |
28 | unsigned long long mask; |
29 | }; |
30 | |
31 | struct gpio_flag flagnames[] = { |
32 | { |
33 | .name = "used" , |
34 | .mask = GPIO_V2_LINE_FLAG_USED, |
35 | }, |
36 | { |
37 | .name = "input" , |
38 | .mask = GPIO_V2_LINE_FLAG_INPUT, |
39 | }, |
40 | { |
41 | .name = "output" , |
42 | .mask = GPIO_V2_LINE_FLAG_OUTPUT, |
43 | }, |
44 | { |
45 | .name = "active-low" , |
46 | .mask = GPIO_V2_LINE_FLAG_ACTIVE_LOW, |
47 | }, |
48 | { |
49 | .name = "open-drain" , |
50 | .mask = GPIO_V2_LINE_FLAG_OPEN_DRAIN, |
51 | }, |
52 | { |
53 | .name = "open-source" , |
54 | .mask = GPIO_V2_LINE_FLAG_OPEN_SOURCE, |
55 | }, |
56 | { |
57 | .name = "pull-up" , |
58 | .mask = GPIO_V2_LINE_FLAG_BIAS_PULL_UP, |
59 | }, |
60 | { |
61 | .name = "pull-down" , |
62 | .mask = GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN, |
63 | }, |
64 | { |
65 | .name = "bias-disabled" , |
66 | .mask = GPIO_V2_LINE_FLAG_BIAS_DISABLED, |
67 | }, |
68 | { |
69 | .name = "clock-realtime" , |
70 | .mask = GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME, |
71 | }, |
72 | }; |
73 | |
74 | static void print_attributes(struct gpio_v2_line_info *info) |
75 | { |
76 | int i; |
77 | const char *field_format = "%s" ; |
78 | |
79 | for (i = 0; i < ARRAY_SIZE(flagnames); i++) { |
80 | if (info->flags & flagnames[i].mask) { |
81 | fprintf(stdout, field_format, flagnames[i].name); |
82 | field_format = ", %s" ; |
83 | } |
84 | } |
85 | |
86 | if ((info->flags & GPIO_V2_LINE_FLAG_EDGE_RISING) && |
87 | (info->flags & GPIO_V2_LINE_FLAG_EDGE_FALLING)) |
88 | fprintf(stdout, field_format, "both-edges" ); |
89 | else if (info->flags & GPIO_V2_LINE_FLAG_EDGE_RISING) |
90 | fprintf(stdout, field_format, "rising-edge" ); |
91 | else if (info->flags & GPIO_V2_LINE_FLAG_EDGE_FALLING) |
92 | fprintf(stdout, field_format, "falling-edge" ); |
93 | |
94 | for (i = 0; i < info->num_attrs; i++) { |
95 | if (info->attrs[i].id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) |
96 | fprintf(stdout, ", debounce_period=%dusec" , |
97 | info->attrs[i].debounce_period_us); |
98 | } |
99 | } |
100 | |
101 | int list_device(const char *device_name) |
102 | { |
103 | struct gpiochip_info cinfo; |
104 | char *chrdev_name; |
105 | int fd; |
106 | int ret; |
107 | int i; |
108 | |
109 | ret = asprintf(&chrdev_name, "/dev/%s" , device_name); |
110 | if (ret < 0) |
111 | return -ENOMEM; |
112 | |
113 | fd = open(chrdev_name, 0); |
114 | if (fd == -1) { |
115 | ret = -errno; |
116 | fprintf(stderr, "Failed to open %s\n" , chrdev_name); |
117 | goto exit_free_name; |
118 | } |
119 | |
120 | /* Inspect this GPIO chip */ |
121 | ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo); |
122 | if (ret == -1) { |
123 | ret = -errno; |
124 | perror("Failed to issue CHIPINFO IOCTL\n" ); |
125 | goto exit_close_error; |
126 | } |
127 | fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n" , |
128 | cinfo.name, cinfo.label, cinfo.lines); |
129 | |
130 | /* Loop over the lines and print info */ |
131 | for (i = 0; i < cinfo.lines; i++) { |
132 | struct gpio_v2_line_info linfo; |
133 | |
134 | memset(&linfo, 0, sizeof(linfo)); |
135 | linfo.offset = i; |
136 | |
137 | ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &linfo); |
138 | if (ret == -1) { |
139 | ret = -errno; |
140 | perror("Failed to issue LINEINFO IOCTL\n" ); |
141 | goto exit_close_error; |
142 | } |
143 | fprintf(stdout, "\tline %2d:" , linfo.offset); |
144 | if (linfo.name[0]) |
145 | fprintf(stdout, " \"%s\"" , linfo.name); |
146 | else |
147 | fprintf(stdout, " unnamed" ); |
148 | if (linfo.consumer[0]) |
149 | fprintf(stdout, " \"%s\"" , linfo.consumer); |
150 | else |
151 | fprintf(stdout, " unused" ); |
152 | if (linfo.flags) { |
153 | fprintf(stdout, " [" ); |
154 | print_attributes(info: &linfo); |
155 | fprintf(stdout, "]" ); |
156 | } |
157 | fprintf(stdout, "\n" ); |
158 | |
159 | } |
160 | |
161 | exit_close_error: |
162 | if (close(fd) == -1) |
163 | perror("Failed to close GPIO character device file" ); |
164 | exit_free_name: |
165 | free(chrdev_name); |
166 | return ret; |
167 | } |
168 | |
169 | void print_usage(void) |
170 | { |
171 | fprintf(stderr, "Usage: lsgpio [options]...\n" |
172 | "List GPIO chips, lines and states\n" |
173 | " -n <name> List GPIOs on a named device\n" |
174 | " -? This helptext\n" |
175 | ); |
176 | } |
177 | |
178 | int main(int argc, char **argv) |
179 | { |
180 | const char *device_name = NULL; |
181 | int ret; |
182 | int c; |
183 | |
184 | while ((c = getopt(argc, argv, "n:" )) != -1) { |
185 | switch (c) { |
186 | case 'n': |
187 | device_name = optarg; |
188 | break; |
189 | case '?': |
190 | print_usage(); |
191 | return -1; |
192 | } |
193 | } |
194 | |
195 | if (device_name) |
196 | ret = list_device(device_name); |
197 | else { |
198 | const struct dirent *ent; |
199 | DIR *dp; |
200 | |
201 | /* List all GPIO devices one at a time */ |
202 | dp = opendir("/dev" ); |
203 | if (!dp) { |
204 | ret = -errno; |
205 | goto error_out; |
206 | } |
207 | |
208 | ret = -ENOENT; |
209 | while (ent = readdir(dp), ent) { |
210 | if (check_prefix(str: ent->d_name, prefix: "gpiochip" )) { |
211 | ret = list_device(device_name: ent->d_name); |
212 | if (ret) |
213 | break; |
214 | } |
215 | } |
216 | |
217 | ret = 0; |
218 | if (closedir(dp) == -1) { |
219 | perror("scanning devices: Failed to close directory" ); |
220 | ret = -errno; |
221 | } |
222 | } |
223 | error_out: |
224 | return ret; |
225 | } |
226 | |