text: /****************************************************************************
   * examplex/djoystick/djoy_main.c
   *
   *   Copyright (C) 2014-2015 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <sys/ioctl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <nuttx/input/djoystick.h>
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  /* Configuration ************************************************************/
  
  #ifndef CONFIG_DJOYSTICK
  #  error "CONFIG_DJOYSTICK is not defined in the configuration"
  #endif
  
  #ifndef CONFIG_EXAMPLES_DJOYSTICK_DEVNAME
  #  define CONFIG_EXAMPLES_DJOYSTICK_DEVNAME "/dev/djoy0"
  #endif
  
  #ifndef CONFIG_EXAMPLES_DJOYSTICK_SIGNO
  #  define CONFIG_EXAMPLES_DJOYSTICK_SIGNO 13
  #endif
  
  /* Helpers ******************************************************************/
  
  #ifndef MIN
  #  define MIN(a,b) (a < b ? a : b)
  #endif
  #ifndef MAX
  #  define MAX(a,b) (a > b ? a : b)
  #endif
  
  /****************************************************************************
   * Private Function Prototypes
   ****************************************************************************/
  
  static void show_joystick(djoy_buttonset_t oldset, djoy_buttonset_t newset);
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  /* The set of supported joystick discretes */
  
  static djoy_buttonset_t g_djoysupported;
  
  /* Last sampled discrete set */
  
  static djoy_buttonset_t g_djoylast;
  
  /* Joystick discrete names */
  
  static const char *g_djoynames[DJOY_NDISCRETES] =
  {
    "UP", "DOWN", "LEFT", "RIGHT", "SELECT", "FIRE", "JUMP", "RUN"
  };
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  static void show_joystick(djoy_buttonset_t oldset, djoy_buttonset_t newset)
  {
    djoy_buttonset_t chgset = oldset ^ newset;
    int i;
  
    /* Show each discrete state change */
  
    for (i = 0; i <= DJOY_NDISCRETES; i++)
      {
        djoy_buttonset_t mask = (1 << i);
        if ((chgset & mask) != 0)
          {
            FAR const char *state;
  
            /* Get the discrete state */
  
            if ((newset & mask) != 0)
              {
                state = "selected";
              }
            else
              {
                state = "released";
              }
  
            printf("  %-6s: %s\n", g_djoynames[i], state);
          }
      }
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * djoy_main
   ****************************************************************************/
  
  int main(int argc, FAR char *argv[])
  {
    struct djoy_notify_s notify;
    int fd;
    int tmp;
    int ret;
    int errcode = EXIT_FAILURE;
  
    /* Reset some globals that might been been left in a bad state */
  
    g_djoylast = 0;
  
    /* Open the djoystick device */
  
    fd = open(CONFIG_EXAMPLES_DJOYSTICK_DEVNAME, O_RDONLY);
    if (fd < 0)
      {
        fprintf(stderr, "ERROR: Failed to open %s: %d\n",
                CONFIG_EXAMPLES_DJOYSTICK_DEVNAME, errno);
        return EXIT_FAILURE;
      }
  
    /* Get the set of supported discretes */
  
    ret = ioctl(fd, DJOYIOC_SUPPORTED,  (unsigned long)((uintptr_t)&tmp));
    if (ret < 0)
      {
        fprintf(stderr, "ERROR: ioctl(DJOYIOC_SUPPORTED) failed: %d\n", errno);
        goto errout_with_fd;
      }
  
    g_djoysupported = (djoy_buttonset_t)tmp;
    printf("Supported joystick discretes:\n");
    show_joystick(0, g_djoysupported);
  
    /* Register to receive a signal on any change in the joystick discretes. */
  
    notify.dn_press   = g_djoysupported;
    notify.dn_release = g_djoysupported;
  
    notify.dn_event.sigev_notify = SIGEV_SIGNAL;
    notify.dn_event.sigev_signo  = CONFIG_EXAMPLES_DJOYSTICK_SIGNO;
  
    ret = ioctl(fd, DJOYIOC_REGISTER, (unsigned long)((uintptr_t)&notify));
    if (ret < 0)
      {
        fprintf(stderr, "ERROR: ioctl(DJOYIOC_REGISTER) failed: %d\n", errno);
        goto errout_with_fd;
      }
  
    /* Then loop, receiving signals indicating joystick events. */
  
    for (;;)
      {
        struct siginfo value;
        sigset_t set;
        djoy_buttonset_t newset;
        ssize_t nread;
  
        /* Wait for a signal */
  
        sigemptyset(&set);
        sigaddset(&set, CONFIG_EXAMPLES_DJOYSTICK_SIGNO);
        ret = sigwaitinfo(&set, &value);
        if (ret < 0)
          {
            fprintf(stderr, "ERROR: sigwaitinfo() failed: %d\n", errno);
            goto errout_with_fd;
          }
  
        /* Show the set of joystick discretes accompanying the signal */
  
        printf("Signalled set\n");
        newset = (djoy_buttonset_t)value.si_value.sival_int;
        show_joystick(g_djoylast, newset);
        g_djoylast = newset;
  
        /* Read the signal set and compare */
  
        nread = read(fd, &newset, sizeof(djoy_buttonset_t));
        if (nread < 0)
          {
            fprintf(stderr, "ERROR: read() failed: %d\n", errno);
            goto errout_with_fd;
          }
        else if (nread != sizeof(djoy_buttonset_t))
          {
            fprintf(stderr, "ERROR: read() unexpected size: %ld vs %d\n",
                    (long)nread, sizeof(djoy_buttonset_t));
            goto errout_with_fd;
          }
  
        /* Show the set of joystick discretes that we just read */
  
        printf("Read set\n");
        show_joystick(g_djoylast, newset);
        g_djoylast = newset;
      }
  
    errcode = EXIT_SUCCESS;
  
  errout_with_fd:
    close(fd);
    return errcode;
  }
  