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