mt_keys.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <sys/stat.h>
   5 #include <fcntl.h>
   6 #include <linux/input.h>
   7 #include <linux/input-event-codes.h>
   8
   9 #include "mt_keys.h"
  10 #include "signal_exit.h"
  11 #include "json_helpers.h"
  12
  13 void keys_json_print(int fd, char key)
  14 {
  15         static const char *type = "keys";
  16
  17         JSON_START();
  18         JSON_STR(type);
  19         JSON_NEXT();
  20         JSON_CHAR(key);
  21         JSON_END();
  22 }
  23
  24 static void keys_cb(EV_P_ ev_io *w_, int revents)
  25 {
  26     ev_io_keys *w = (ev_io_keys *)w_;
  27     int fd = w->fd;
  28     struct input_event ev;
  29     char key;
  30     ssize_t n = read(w->w.fd, &ev, sizeof(ev));
  31     if (n != sizeof(ev)) {
  32         perror("read");
  33         return;
  34     }
  35     if (ev.type == 1 && ev.value == 1) {
  36         switch (ev.code) {
  37             case BTN_TRIGGER_HAPPY1:
  38                 key = 'A';
  39                 break;
  40             case BTN_TRIGGER_HAPPY2:
  41                 key = 'B';
  42                 break;
  43             case BTN_TRIGGER_HAPPY3:
  44                 key = 'C';
  45                 break;
  46             case BTN_TRIGGER_HAPPY4:
  47                 key = 'D';
  48                 break;
  49             case BTN_TRIGGER_HAPPY5:
  50                 key = 'E';
  51                 break;
  52             case BTN_TRIGGER_HAPPY6:
  53                 key = 'F';
  54                 break;
  55             case BTN_TRIGGER_HAPPY7:
  56                 key = 'G';
  57                 break;
  58             case BTN_TRIGGER_HAPPY8:
  59                 key = 'H';
  60                 break;
  61             case BTN_TRIGGER_HAPPY9:
  62                 key = 'I';
  63                 break;
  64             case BTN_TRIGGER_HAPPY10:
  65                 key = 'J';
  66                 break;
  67             case BTN_TRIGGER_HAPPY11:
  68                 key = 'K';
  69                 break;
  70             case BTN_TRIGGER_HAPPY12:
  71                 key = 'L';
  72                 break;
  73             case BTN_TRIGGER_HAPPY13:
  74                 key = 'M';
  75                 break;
  76             case BTN_TRIGGER_HAPPY14:
  77                 key = 'N';
  78                 break;
  79             case BTN_TRIGGER_HAPPY15:
  80                 key = 'O';
  81                 break;
  82             case BTN_TRIGGER_HAPPY16:
  83                 key = 'P';
  84                 break;
  85             case BTN_TRIGGER_HAPPY17:
  86                 key = 'Q';
  87                 break;
  88             case BTN_TRIGGER_HAPPY18:
  89                 key = 'R';
  90                 break;
  91             case BTN_TRIGGER_HAPPY19:
  92                 key = 'S';
  93                 break;
  94             case BTN_TRIGGER_HAPPY20:
  95                 key = 'T';
  96                 break;
  97             default:
  98                 fprintf(stderr, "unsupported event code: %d\n", ev.code);
  99                 key = '?';
 100                 //return;
 101         }
 102
 103         keys_json_print(fd, key);
 104     }
 105 }
 106
 107 int mt_keys_init(mt_keys_t *self, struct ev_loop *loop, int fd)
 108 {
 109     char *dev = getenv("INPUT");
 110
 111     if (!dev)
 112         dev = "/dev/input/by-path/platform-gpio-keys-event";
 113
 114     int ev = open(dev, O_RDONLY);
 115     if (ev == -1) {
 116         perror(dev);
 117         return -1;
 118     }
 119
 120     self->fd = ev;
 121     ev_io_keys *w = &(self->w);
 122     w->fd = fd;
 123     ev_io_init(&(w->w), keys_cb, ev, EV_READ);
 124     ev_io_start(loop, (ev_io *)w);
 125
 126     return 0;
 127 }
 128
 129 void mt_keys_deinit(mt_keys_t *self)
 130 {
 131     if (close(self->fd) == 0) {
 132         fprintf(stderr, "closed %d\n", self->fd);
 133     } else {
 134         perror("close");
 135     }
 136 }
 137
 138 #ifndef NO_MAIN
 139 int main(int argc, char **argv)
 140 {
 141     struct ev_loop *loop = EV_DEFAULT;
 142     mt_keys_t keys;
 143
 144     set_signal_exit(loop);
 145
 146     if (mt_keys_init(&keys, loop, STDOUT_FILENO) != 0) {
 147         return -1;
 148     }
 149
 150     ev_run(loop, 0);
 151
 152     mt_keys_deinit(&keys);
 153     ev_loop_destroy(loop);
 154
 155     return 0;
 156 }
 157 #endif