/* hid_gadget_test */

  #include <pthread.h>
  #include <string.h>
  #include <stdio.h>
  #include <ctype.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>

  #define BUF_LEN 512

  struct options {
      const char    *opt;
      unsigned char val;
};

static struct options kmod[] = {
      {.opt = "--left-ctrl",          .val = 0x01},
      {.opt = "--right-ctrl",         .val = 0x10},
      {.opt = "--left-shift",         .val = 0x02},
      {.opt = "--right-shift",        .val = 0x20},
      {.opt = "--left-alt",           .val = 0x04},
      {.opt = "--right-alt",          .val = 0x40},
      {.opt = "--left-meta",          .val = 0x08},
      {.opt = "--right-meta",         .val = 0x80},
      {.opt = NULL}
};

static struct options kval[] = {
      {.opt = "--return",     .val = 0x28},
      {.opt = "--esc",        .val = 0x29},
      {.opt = "--bckspc",     .val = 0x2a},
      {.opt = "--tab",        .val = 0x2b},
      {.opt = "--spacebar",   .val = 0x2c},
      {.opt = "--caps-lock",  .val = 0x39},
      {.opt = "--f1",         .val = 0x3a},
      {.opt = "--f2",         .val = 0x3b},
      {.opt = "--f3",         .val = 0x3c},
      {.opt = "--f4",         .val = 0x3d},
      {.opt = "--f5",         .val = 0x3e},
      {.opt = "--f6",         .val = 0x3f},
      {.opt = "--f7",         .val = 0x40},
      {.opt = "--f8",         .val = 0x41},
      {.opt = "--f9",         .val = 0x42},
      {.opt = "--f10",        .val = 0x43},
      {.opt = "--f11",        .val = 0x44},
      {.opt = "--f12",        .val = 0x45},
      {.opt = "--insert",     .val = 0x49},
      {.opt = "--home",       .val = 0x4a},
      {.opt = "--pageup",     .val = 0x4b},
      {.opt = "--del",        .val = 0x4c},
      {.opt = "--end",        .val = 0x4d},
      {.opt = "--pagedown",   .val = 0x4e},
      {.opt = "--right",      .val = 0x4f},
      {.opt = "--left",       .val = 0x50},
      {.opt = "--down",       .val = 0x51},
      {.opt = "--kp-enter",   .val = 0x58},
      {.opt = "--up",         .val = 0x52},
      {.opt = "--num-lock",   .val = 0x53},
      {.opt = NULL}
};

int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold)
{
      char *tok = strtok(buf, " ");
      int key = 0;
      int i = 0;

      for (; tok != NULL; tok = strtok(NULL, " ")) {

              if (strcmp(tok, "--quit") == 0)
                      return -1;

              if (strcmp(tok, "--hold") == 0) {
                      *hold = 1;
                      continue;
              }

              if (key < 6) {
                      for (i = 0; kval[i].opt != NULL; i++)
                              if (strcmp(tok, kval[i].opt) == 0) {
                                      report[2 + key++] = kval[i].val;
                                      break;
                              }
                      if (kval[i].opt != NULL)
                              continue;
              }

              if (key < 6)
                      if (islower(tok[0])) {
                              report[2 + key++] = (tok[0] - ('a' - 0x04));
                              continue;
                      }

              for (i = 0; kmod[i].opt != NULL; i++)
                      if (strcmp(tok, kmod[i].opt) == 0) {
                              report[0] = report[0] | kmod[i].val;
                              break;
                      }
              if (kmod[i].opt != NULL)
                      continue;

              if (key < 6)
                      fprintf(stderr, "unknown option: %s\n", tok);
      }
      return 8;
}

static struct options mmod[] = {
      {.opt = "--b1", .val = 0x01},
      {.opt = "--b2", .val = 0x02},
      {.opt = "--b3", .val = 0x04},
      {.opt = NULL}
};

int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold)
{
      char *tok = strtok(buf, " ");
      int mvt = 0;
      int i = 0;
      for (; tok != NULL; tok = strtok(NULL, " ")) {

              if (strcmp(tok, "--quit") == 0)
                      return -1;

              if (strcmp(tok, "--hold") == 0) {
                      *hold = 1;
                      continue;
              }

              for (i = 0; mmod[i].opt != NULL; i++)
                      if (strcmp(tok, mmod[i].opt) == 0) {
                              report[0] = report[0] | mmod[i].val;
                              break;
                      }
              if (mmod[i].opt != NULL)
                      continue;

              if (!(tok[0] == '-' && tok[1] == '-') && mvt < 2) {
                      errno = 0;
                      report[1 + mvt++] = (char)strtol(tok, NULL, 0);
                      if (errno != 0) {
                              fprintf(stderr, "Bad value:'%s'\n", tok);
                              report[1 + mvt--] = 0;
                      }
                      continue;
              }

              fprintf(stderr, "unknown option: %s\n", tok);
      }
      return 3;
}

static struct options jmod[] = {
      {.opt = "--b1",         .val = 0x10},
      {.opt = "--b2",         .val = 0x20},
      {.opt = "--b3",         .val = 0x40},
      {.opt = "--b4",         .val = 0x80},
      {.opt = "--hat1",       .val = 0x00},
      {.opt = "--hat2",       .val = 0x01},
      {.opt = "--hat3",       .val = 0x02},
      {.opt = "--hat4",       .val = 0x03},
      {.opt = "--hatneutral", .val = 0x04},
      {.opt = NULL}
};

int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold)
{
      char *tok = strtok(buf, " ");
      int mvt = 0;
      int i = 0;

      *hold = 1;

      /* set default hat position: neutral */
      report[3] = 0x04;

      for (; tok != NULL; tok = strtok(NULL, " ")) {

              if (strcmp(tok, "--quit") == 0)
                      return -1;

              for (i = 0; jmod[i].opt != NULL; i++)
                      if (strcmp(tok, jmod[i].opt) == 0) {
                              report[3] = (report[3] & 0xF0) | jmod[i].val;
                              break;
                      }
              if (jmod[i].opt != NULL)
                      continue;

              if (!(tok[0] == '-' && tok[1] == '-') && mvt < 3) {
                      errno = 0;
                      report[mvt++] = (char)strtol(tok, NULL, 0);
                      if (errno != 0) {
                              fprintf(stderr, "Bad value:'%s'\n", tok);
                              report[mvt--] = 0;
                      }
                      continue;
              }

              fprintf(stderr, "unknown option: %s\n", tok);
      }
      return 4;
}

void print_options(char c)
{
      int i = 0;

      if (c == 'k') {
              printf("        keyboard options:\n"
                     "                --hold\n");
              for (i = 0; kmod[i].opt != NULL; i++)
                      printf("\t\t%s\n", kmod[i].opt);
              printf("\n      keyboard values:\n"
                     "                [a-z] or\n");
              for (i = 0; kval[i].opt != NULL; i++)
                      printf("\t\t%-8s%s", kval[i].opt, i % 2 ? "\n" : "");
              printf("\n");
      } else if (c == 'm') {
              printf("        mouse options:\n"
                     "                --hold\n");
              for (i = 0; mmod[i].opt != NULL; i++)
                      printf("\t\t%s\n", mmod[i].opt);
              printf("\n      mouse values:\n"
                     "                Two signed numbers\n"
                     "--quit to close\n");
      } else {
              printf("        joystick options:\n");
              for (i = 0; jmod[i].opt != NULL; i++)
                      printf("\t\t%s\n", jmod[i].opt);
              printf("\n      joystick values:\n"
                     "                three signed numbers\n"
                     "--quit to close\n");
      }
}

int main(int argc, const char *argv[])
{
      const char *filename = NULL;
      int fd = 0;
      char buf[BUF_LEN];
      int cmd_len;
      char report[8];
      int to_send = 8;
      int hold = 0;
      fd_set rfds;
      int retval, i;

      if (argc < 3) {
              fprintf(stderr, "Usage: %s devname mouse|keyboard|joystick\n",
                      argv[0]);
              return 1;
      }

      if (argv[2][0] != 'k' && argv[2][0] != 'm' && argv[2][0] != 'j')
        return 2;

      filename = argv[1];

      if ((fd = open(filename, O_RDWR, 0666)) == -1) {
              perror(filename);
              return 3;
      }

      print_options(argv[2][0]);

      while (42) {

              FD_ZERO(&rfds);
              FD_SET(STDIN_FILENO, &rfds);
              FD_SET(fd, &rfds);

              retval = select(fd + 1, &rfds, NULL, NULL, NULL);
              if (retval == -1 && errno == EINTR)
                      continue;
              if (retval < 0) {
                      perror("select()");
                      return 4;
              }

              if (FD_ISSET(fd, &rfds)) {
                      cmd_len = read(fd, buf, BUF_LEN - 1);
                      printf("recv report:");
                      for (i = 0; i < cmd_len; i++)
                              printf(" %02x", buf[i]);
                      printf("\n");
              }

              if (FD_ISSET(STDIN_FILENO, &rfds)) {
                      memset(report, 0x0, sizeof(report));
                      cmd_len = read(STDIN_FILENO, buf, BUF_LEN - 1);

                      if (cmd_len == 0)
                              break;

                      buf[cmd_len - 1] = '\0';
                      hold = 0;

                      memset(report, 0x0, sizeof(report));
                      if (argv[2][0] == 'k')
                              to_send = keyboard_fill_report(report, buf, &hold);
                      else if (argv[2][0] == 'm')
                              to_send = mouse_fill_report(report, buf, &hold);
                      else
                              to_send = joystick_fill_report(report, buf, &hold);

                      if (to_send == -1)
                              break;

                      if (write(fd, report, to_send) != to_send) {
                              perror(filename);
                              return 5;
                      }
                      if (!hold) {
                              memset(report, 0x0, sizeof(report));
                              if (write(fd, report, to_send) != to_send) {
                                      perror(filename);
                                      return 6;
                              }
                      }
              }
      }

      close(fd);
      return 0;
}