| 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 void setport(int p, int v) |
| 10 | { |
| 11 | char path[256], line[256]; |
| 12 | FILE *fp; |
| 13 | int rv; |
| 14 | |
| 15 | sprintf(path, "/sys/class/gpio/gpio%i/direction", p); |
| 16 | if((fp = fopen(path, "r")) == NULL) |
| 17 | err(1, "%s", path); |
| 18 | rv = !!fgets(line, sizeof(line), fp); |
| 19 | fclose(fp); |
| 20 | if(!rv || strcmp(line, "out\n")) { |
| 21 | if((fp = fopen(path, "w")) == NULL) |
| 22 | err(1, "%s", path); |
| 23 | fprintf(fp, "out\n"); fflush(fp); |
| 24 | if(ferror(fp)) |
| 25 | errx(1, "gpio%i: could not set to output", p); |
| 26 | fclose(fp); |
| 27 | } |
| 28 | sprintf(path, "/sys/class/gpio/gpio%i/value", p); |
| 29 | if((fp = fopen(path, "w")) == NULL) |
| 30 | err(1, "%s", path); |
| 31 | fprintf(fp, "%i\n", v); fflush(fp); |
| 32 | if(ferror(fp)) |
| 33 | errx(1, "gpio%i: could not set value", p); |
| 34 | fclose(fp); |
| 35 | } |
| 36 | |
| 37 | int main(int argc, char **argv) |
| 38 | { |
| 39 | int i, port, val; |
| 40 | char *p, *e; |
| 41 | |
| 42 | for(i = 1; i < argc; i++) { |
| 43 | if((p = strchr(argv[i], '=')) == NULL) { |
| 44 | fprintf(stderr, "gpio: %s: not of the form PORT=VAL\n", argv[i]); |
| 45 | exit(1); |
| 46 | } |
| 47 | port = strtol(argv[i], &e, 10); |
| 48 | if(e != p) { |
| 49 | fprintf(stderr, "gpio: %s: not of the form PORT=VAL\n", argv[i]); |
| 50 | exit(1); |
| 51 | } |
| 52 | val = strtol(p + 1, &e, 10); |
| 53 | if(*e) { |
| 54 | fprintf(stderr, "gpio: %s: not of the form PORT=VAL\n", argv[i]); |
| 55 | exit(1); |
| 56 | } |
| 57 | setport(port, val); |
| 58 | } |
| 59 | return(0); |
| 60 | } |