| 1 | #include <unistd.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <stdio.h> |
| 4 | #include <string.h> |
| 5 | #include <fcntl.h> |
| 6 | #include <errno.h> |
| 7 | #include <err.h> |
| 8 | |
| 9 | static const int bmap[] = { |
| 10 | -1, |
| 11 | -1, -1, 2, -1, 3, -1, 4, 14, -1, 15, 17, 18, 27, -1, 22, 23, -1, 24, 10, -1, |
| 12 | 9, 25, 11, 8, -1, 7, -1, -1, 5, -1, 6, 12, 13, -1, 19, 16, 21, 20, -1, 21, |
| 13 | }; |
| 14 | static const int imap[] = { |
| 15 | -1, -1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, |
| 16 | 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, 27, |
| 17 | }; |
| 18 | static const int *umap = bmap; |
| 19 | static int mapn = sizeof(bmap) / sizeof(*bmap); |
| 20 | static int preserve = 0; |
| 21 | |
| 22 | static int mappin(int num) |
| 23 | { |
| 24 | if((num < 0) || (num >= mapn)) |
| 25 | return(-1); |
| 26 | return(umap[num]); |
| 27 | } |
| 28 | |
| 29 | static void export(int p) |
| 30 | { |
| 31 | char path[256]; |
| 32 | FILE *fp; |
| 33 | int rp; |
| 34 | |
| 35 | if((rp = mappin(p)) < 0) |
| 36 | errx(1, "%i: no such port", p); |
| 37 | sprintf(path, "/sys/class/gpio/gpio%i", rp); |
| 38 | if(!access(path, R_OK | X_OK)) |
| 39 | return; |
| 40 | if(preserve) |
| 41 | errx(2, "gpio%i: not exported", rp); |
| 42 | sprintf(path, "/sys/class/gpio/export"); |
| 43 | if((fp = fopen(path, "w")) == NULL) |
| 44 | err(1, "%s", path); |
| 45 | fprintf(fp, "%i\n", rp); fflush(fp); |
| 46 | if(ferror(fp)) |
| 47 | errx(1, "gpio%i: could not export", rp); |
| 48 | fclose(fp); |
| 49 | sprintf(path, "/sys/class/gpio/gpio%i", rp); |
| 50 | if(access(path, R_OK | X_OK)) |
| 51 | errx(1, "gpio%i: still not available after export", rp); |
| 52 | } |
| 53 | |
| 54 | static void checkdir(int rp, char *dir) |
| 55 | { |
| 56 | char path[256], line[256]; |
| 57 | FILE *fp; |
| 58 | int rv; |
| 59 | size_t ln; |
| 60 | |
| 61 | sprintf(path, "/sys/class/gpio/gpio%i/direction", rp); |
| 62 | if((fp = fopen(path, "r")) == NULL) |
| 63 | err(1, "%s", path); |
| 64 | rv = !!fgets(line, sizeof(line), fp); |
| 65 | fclose(fp); |
| 66 | if(!rv || ((ln = strlen(line)) < 1) || (line[ln - 1] != '\n')) |
| 67 | errx(1, "gpio%i: could not read direction", rp); |
| 68 | line[ln - 1] = 0; |
| 69 | if(strcmp(line, dir)) { |
| 70 | if(preserve) |
| 71 | errx(2, "gpio%i: direction not set to %s", rp, dir); |
| 72 | if((fp = fopen(path, "w")) == NULL) |
| 73 | err(1, "%s", path); |
| 74 | fprintf(fp, "%s\n", dir); fflush(fp); |
| 75 | if(ferror(fp)) |
| 76 | errx(1, "gpio%i: could not set to direction to %s", rp, dir); |
| 77 | fclose(fp); |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | static void setport(int p, int v) |
| 82 | { |
| 83 | char path[256]; |
| 84 | FILE *fp; |
| 85 | int rp; |
| 86 | |
| 87 | if((rp = mappin(p)) < 0) |
| 88 | errx(1, "%i: no such port", p); |
| 89 | checkdir(rp, "out"); |
| 90 | sprintf(path, "/sys/class/gpio/gpio%i/value", rp); |
| 91 | if((fp = fopen(path, "w")) == NULL) |
| 92 | err(1, "%s", path); |
| 93 | fprintf(fp, "%i\n", v); fflush(fp); |
| 94 | if(ferror(fp)) |
| 95 | errx(1, "gpio%i: could not set value", rp); |
| 96 | fclose(fp); |
| 97 | } |
| 98 | |
| 99 | static int getport(int p) |
| 100 | { |
| 101 | char path[256], line[256], *ep; |
| 102 | FILE *fp; |
| 103 | int rv, rp; |
| 104 | size_t ln; |
| 105 | |
| 106 | if((rp = mappin(p)) < 0) |
| 107 | errx(1, "%i: no such port", p); |
| 108 | checkdir(rp, "in"); |
| 109 | sprintf(path, "/sys/class/gpio/gpio%i/value", rp); |
| 110 | if((fp = fopen(path, "r")) == NULL) |
| 111 | err(1, "%s", path); |
| 112 | rv = !!fgets(line, sizeof(line), fp); |
| 113 | fclose(fp); |
| 114 | if(!rv || ((ln = strlen(line)) < 1) || (line[ln - 1] != '\n')) |
| 115 | errx(1, "gpio%i: could not read direction", rp); |
| 116 | line[ln - 1] = 0; |
| 117 | rv = (int)strtol(line, &ep, 10); |
| 118 | if(*ep) |
| 119 | errx(1, "gpio%i: unexpected contents: %s", rp, line); |
| 120 | return(rv); |
| 121 | } |
| 122 | |
| 123 | static void usage(FILE *out) |
| 124 | { |
| 125 | fprintf(out, "usage: gpio [-hip] {PORT=VAL|PORT==VAL|PORT?}...\n"); |
| 126 | } |
| 127 | |
| 128 | int main(int argc, char **argv) |
| 129 | { |
| 130 | int c, i, port, val; |
| 131 | char *e; |
| 132 | |
| 133 | while((c = getopt(argc, argv, "hip")) >= 0) { |
| 134 | switch(c) { |
| 135 | case 'h': |
| 136 | usage(stdout); |
| 137 | return(0); |
| 138 | case 'i': |
| 139 | umap = imap; |
| 140 | mapn = sizeof(imap) / sizeof(*imap); |
| 141 | break; |
| 142 | case 'p': |
| 143 | preserve = 1; |
| 144 | break; |
| 145 | default: |
| 146 | usage(stderr); |
| 147 | return(1); |
| 148 | } |
| 149 | } |
| 150 | if(optind >= argc) { |
| 151 | usage(stderr); |
| 152 | return(1); |
| 153 | } |
| 154 | for(i = optind; i < argc; i++) { |
| 155 | port = strtol(argv[i], &e, 10); |
| 156 | if((e > argv[i]) && (e[0] == '=') && (e[1] == '=')) { |
| 157 | val = strtol(e + 2, &e, 10); |
| 158 | if(*e) |
| 159 | errx(1, "gpio: %s: not of the form PORT==VAL", argv[i]); |
| 160 | export(port); |
| 161 | return(getport(port) != val); |
| 162 | } else if((e > argv[i]) && (e[0] == '=')) { |
| 163 | val = strtol(e + 1, &e, 10); |
| 164 | if(*e) |
| 165 | errx(1, "gpio: %s: not of the form PORT=VAL", argv[i]); |
| 166 | export(port); |
| 167 | setport(port, val); |
| 168 | } else if((e > argv[i]) && (e[0] == '?') && !e[1]) { |
| 169 | export(port); |
| 170 | printf("%i\n", getport(port)); |
| 171 | } else { |
| 172 | errx(1, "gpio: %s: not a valid argument", argv[i]); |
| 173 | } |
| 174 | } |
| 175 | return(0); |
| 176 | } |
| 177 | |
| 178 | /* |
| 179 | * Local Variables: |
| 180 | * compile-command: "gcc -Wall -g -O2 -march=native -c -o gpio.o gpio.c && gcc -o gpio gpio.o" |
| 181 | * End: |
| 182 | */ |