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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6d591c46 LW |
2 | /* |
3 | * lsgpio - example on how to list the GPIO lines on a system | |
4 | * | |
5 | * Copyright (C) 2015 Linus Walleij | |
6 | * | |
6d591c46 LW |
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 | ||
521a2ad6 LW |
26 | struct gpio_flag { |
27 | char *name; | |
3c333c47 | 28 | unsigned long long mask; |
521a2ad6 LW |
29 | }; |
30 | ||
31 | struct gpio_flag flagnames[] = { | |
32 | { | |
3c333c47 KG |
33 | .name = "used", |
34 | .mask = GPIO_V2_LINE_FLAG_USED, | |
35 | }, | |
36 | { | |
37 | .name = "input", | |
38 | .mask = GPIO_V2_LINE_FLAG_INPUT, | |
521a2ad6 LW |
39 | }, |
40 | { | |
41 | .name = "output", | |
3c333c47 | 42 | .mask = GPIO_V2_LINE_FLAG_OUTPUT, |
521a2ad6 LW |
43 | }, |
44 | { | |
45 | .name = "active-low", | |
3c333c47 | 46 | .mask = GPIO_V2_LINE_FLAG_ACTIVE_LOW, |
521a2ad6 LW |
47 | }, |
48 | { | |
49 | .name = "open-drain", | |
3c333c47 | 50 | .mask = GPIO_V2_LINE_FLAG_OPEN_DRAIN, |
521a2ad6 LW |
51 | }, |
52 | { | |
53 | .name = "open-source", | |
3c333c47 | 54 | .mask = GPIO_V2_LINE_FLAG_OPEN_SOURCE, |
521a2ad6 | 55 | }, |
3831c051 KG |
56 | { |
57 | .name = "pull-up", | |
3c333c47 | 58 | .mask = GPIO_V2_LINE_FLAG_BIAS_PULL_UP, |
3831c051 KG |
59 | }, |
60 | { | |
61 | .name = "pull-down", | |
3c333c47 | 62 | .mask = GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN, |
3831c051 KG |
63 | }, |
64 | { | |
65 | .name = "bias-disabled", | |
3c333c47 | 66 | .mask = GPIO_V2_LINE_FLAG_BIAS_DISABLED, |
3831c051 | 67 | }, |
521a2ad6 LW |
68 | }; |
69 | ||
3c333c47 | 70 | static void print_attributes(struct gpio_v2_line_info *info) |
521a2ad6 LW |
71 | { |
72 | int i; | |
3c333c47 | 73 | const char *field_format = "%s"; |
521a2ad6 LW |
74 | |
75 | for (i = 0; i < ARRAY_SIZE(flagnames); i++) { | |
3c333c47 KG |
76 | if (info->flags & flagnames[i].mask) { |
77 | fprintf(stdout, field_format, flagnames[i].name); | |
78 | field_format = ", %s"; | |
521a2ad6 LW |
79 | } |
80 | } | |
3c333c47 KG |
81 | |
82 | if ((info->flags & GPIO_V2_LINE_FLAG_EDGE_RISING) && | |
83 | (info->flags & GPIO_V2_LINE_FLAG_EDGE_FALLING)) | |
84 | fprintf(stdout, field_format, "both-edges"); | |
85 | else if (info->flags & GPIO_V2_LINE_FLAG_EDGE_RISING) | |
86 | fprintf(stdout, field_format, "rising-edge"); | |
87 | else if (info->flags & GPIO_V2_LINE_FLAG_EDGE_FALLING) | |
88 | fprintf(stdout, field_format, "falling-edge"); | |
89 | ||
90 | for (i = 0; i < info->num_attrs; i++) { | |
91 | if (info->attrs[i].id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) | |
92 | fprintf(stdout, ", debounce_period=%dusec", | |
93 | info->attrs[0].debounce_period_us); | |
94 | } | |
521a2ad6 LW |
95 | } |
96 | ||
6d591c46 LW |
97 | int list_device(const char *device_name) |
98 | { | |
99 | struct gpiochip_info cinfo; | |
100 | char *chrdev_name; | |
101 | int fd; | |
102 | int ret; | |
521a2ad6 | 103 | int i; |
6d591c46 LW |
104 | |
105 | ret = asprintf(&chrdev_name, "/dev/%s", device_name); | |
106 | if (ret < 0) | |
107 | return -ENOMEM; | |
108 | ||
109 | fd = open(chrdev_name, 0); | |
110 | if (fd == -1) { | |
111 | ret = -errno; | |
112 | fprintf(stderr, "Failed to open %s\n", chrdev_name); | |
ef3c61a0 | 113 | goto exit_free_name; |
6d591c46 LW |
114 | } |
115 | ||
116 | /* Inspect this GPIO chip */ | |
117 | ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo); | |
118 | if (ret == -1) { | |
119 | ret = -errno; | |
521a2ad6 LW |
120 | perror("Failed to issue CHIPINFO IOCTL\n"); |
121 | goto exit_close_error; | |
6d591c46 | 122 | } |
df4878e9 LW |
123 | fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n", |
124 | cinfo.name, cinfo.label, cinfo.lines); | |
6d591c46 | 125 | |
521a2ad6 LW |
126 | /* Loop over the lines and print info */ |
127 | for (i = 0; i < cinfo.lines; i++) { | |
3c333c47 | 128 | struct gpio_v2_line_info linfo; |
521a2ad6 LW |
129 | |
130 | memset(&linfo, 0, sizeof(linfo)); | |
3c333c47 | 131 | linfo.offset = i; |
521a2ad6 | 132 | |
3c333c47 | 133 | ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &linfo); |
521a2ad6 LW |
134 | if (ret == -1) { |
135 | ret = -errno; | |
136 | perror("Failed to issue LINEINFO IOCTL\n"); | |
137 | goto exit_close_error; | |
138 | } | |
3c333c47 | 139 | fprintf(stdout, "\tline %2d:", linfo.offset); |
521a2ad6 | 140 | if (linfo.name[0]) |
bb91d345 | 141 | fprintf(stdout, " \"%s\"", linfo.name); |
521a2ad6 LW |
142 | else |
143 | fprintf(stdout, " unnamed"); | |
214338e3 LW |
144 | if (linfo.consumer[0]) |
145 | fprintf(stdout, " \"%s\"", linfo.consumer); | |
521a2ad6 | 146 | else |
214338e3 | 147 | fprintf(stdout, " unused"); |
521a2ad6 LW |
148 | if (linfo.flags) { |
149 | fprintf(stdout, " ["); | |
3c333c47 | 150 | print_attributes(&linfo); |
521a2ad6 LW |
151 | fprintf(stdout, "]"); |
152 | } | |
153 | fprintf(stdout, "\n"); | |
154 | ||
6d591c46 LW |
155 | } |
156 | ||
521a2ad6 LW |
157 | exit_close_error: |
158 | if (close(fd) == -1) | |
159 | perror("Failed to close GPIO character device file"); | |
ef3c61a0 | 160 | exit_free_name: |
6d591c46 | 161 | free(chrdev_name); |
6d591c46 | 162 | return ret; |
6d591c46 LW |
163 | } |
164 | ||
165 | void print_usage(void) | |
166 | { | |
167 | fprintf(stderr, "Usage: lsgpio [options]...\n" | |
168 | "List GPIO chips, lines and states\n" | |
169 | " -n <name> List GPIOs on a named device\n" | |
170 | " -? This helptext\n" | |
171 | ); | |
172 | } | |
173 | ||
174 | int main(int argc, char **argv) | |
175 | { | |
691998fa | 176 | const char *device_name = NULL; |
6d591c46 LW |
177 | int ret; |
178 | int c; | |
179 | ||
180 | while ((c = getopt(argc, argv, "n:")) != -1) { | |
181 | switch (c) { | |
182 | case 'n': | |
183 | device_name = optarg; | |
184 | break; | |
185 | case '?': | |
186 | print_usage(); | |
187 | return -1; | |
188 | } | |
189 | } | |
190 | ||
191 | if (device_name) | |
192 | ret = list_device(device_name); | |
193 | else { | |
194 | const struct dirent *ent; | |
195 | DIR *dp; | |
196 | ||
197 | /* List all GPIO devices one at a time */ | |
198 | dp = opendir("/dev"); | |
199 | if (!dp) { | |
200 | ret = -errno; | |
201 | goto error_out; | |
202 | } | |
203 | ||
204 | ret = -ENOENT; | |
205 | while (ent = readdir(dp), ent) { | |
206 | if (check_prefix(ent->d_name, "gpiochip")) { | |
207 | ret = list_device(ent->d_name); | |
208 | if (ret) | |
209 | break; | |
210 | } | |
211 | } | |
212 | ||
213 | ret = 0; | |
214 | if (closedir(dp) == -1) { | |
215 | perror("scanning devices: Failed to close directory"); | |
216 | ret = -errno; | |
217 | } | |
218 | } | |
219 | error_out: | |
220 | return ret; | |
221 | } |