text: /****************************************************************************
   * apps/examples/chrono/chrono_main.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <sys/ioctl.h>
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <time.h>
  #include <sys/time.h>
  
  #include <nuttx/input/buttons.h>
  
  #include <nuttx/lcd/slcd_ioctl.h>
  #include <nuttx/lcd/slcd_codec.h>
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  #define BUTTON_SIGNO 13
  #define BUTTON_STACKSIZE 2048
  #define BUTTON_PRIORITY 100
  #define BUTTON_DEVPATH "/dev/buttons"
  
  #define SLCD_DEVNAME "/dev/slcd0"
  #define SLCD_BUFSIZE 8
  
  /****************************************************************************
   * Private Types
   ****************************************************************************/
  
  /* What is the current chronometer status? */
  
  enum chronostate_e
  {
    CHRONO_RESETED = 0,
    CHRONO_RUNNING,
    CHRONO_STOPPED,
  };
  
  /* All state information for this test is kept within the following structure
   * in order create a namespace and to minimize the possibility of name
   * collisions.
   *
   * NOTE: stream must be the first element of struct slcd_chrono_s to support
   * casting between these two types.
   */
  
  struct slcd_chrono_s
  {
    struct lib_outstream_s   stream;      /* Stream to use for all output */
    struct slcd_attributes_s attr;        /* Size of the SLCD (rows x columns) */
    int                      fd;          /* File descriptor or the open SLCD device */
    bool                     initialized; /* TRUE:  Initialized */
    struct timespec          ts_start;    /* Store the initial time */
    struct timespec          ts_end;      /* Store the final time */
    int                      state;
  
    /* The I/O buffer */
  
    uint8_t buffer[SLCD_BUFSIZE];
  };
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  static struct slcd_chrono_s g_slcd;
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: chrono_daemon
   ****************************************************************************/
  
  static int chrono_daemon(int argc, char *argv[])
  {
    FAR struct slcd_chrono_s *priv = &g_slcd;
    struct btn_notify_s btnevents;
    btn_buttonset_t supported;
  
    int ret;
    int fd;
    int i;
  
    UNUSED(i);
  
    printf("chrono_daemon: Running\n");
  
    /* Open the BUTTON driver */
  
    printf("chrono_daemon: Opening %s\n", BUTTON_DEVPATH);
    fd = open(BUTTON_DEVPATH, O_RDONLY | O_NONBLOCK);
    if (fd < 0)
      {
        int errcode = errno;
        printf("chrono_daemon: ERROR: Failed to open %s: %d\n",
               BUTTON_DEVPATH, errcode);
        goto errout;
      }
  
    /* Get the set of BUTTONs supported */
  
    ret = ioctl(fd, BTNIOC_SUPPORTED,
                (unsigned long)((uintptr_t)&supported));
    if (ret < 0)
      {
        int errcode = errno;
        printf("chrono_daemon: ERROR: ioctl(BTNIOC_SUPPORTED) failed: %d\n",
               errcode);
        goto errout_with_fd;
      }
  
    printf("chrono_daemon: Supported BUTTONs 0x%02x\n",
           (unsigned int)supported);
  
    /* Define the notifications events */
  
    btnevents.bn_press   = supported;
    btnevents.bn_release = supported;
  
    btnevents.bn_event.sigev_notify = SIGEV_SIGNAL;
    btnevents.bn_event.sigev_signo  = BUTTON_SIGNO;
  
    /* Register to receive a signal when buttons are pressed/released */
  
    ret = ioctl(fd, BTNIOC_REGISTER,
                (unsigned long)((uintptr_t)&btnevents));
    if (ret < 0)
      {
        int errcode = errno;
        printf("chrono_daemon: ERROR: ioctl(BTNIOC_REGISTER) failed: %d\n",
               errcode);
        goto errout_with_fd;
      }
  
    /* Ignore the default signal action */
  
    signal(BUTTON_SIGNO, SIG_IGN);
  
    /* Now loop forever, waiting BUTTONs events */
  
    for (; ; )
      {
        struct siginfo value;
        sigset_t set;
  
        /* Wait for a signal */
  
        sigemptyset(&set);
        sigaddset(&set, BUTTON_SIGNO);
        ret = sigwaitinfo(&set, &value);
        if (ret < 0)
          {
            int errcode = errno;
            printf("chrono_daemon: ERROR: sigwaitinfo() failed: %d\n",
                   errcode);
            goto errout_with_fd;
          }
  
        if (priv->state == CHRONO_STOPPED)
          {
            clock_gettime(CLOCK_MONOTONIC, &priv->ts_start);
            priv->state = CHRONO_RUNNING;
          }
        else
          {
            priv->state = CHRONO_STOPPED;
          }
  
        /* Make sure that everything is displayed */
  
        fflush(stdout);
  
        usleep(1000);
      }
  
  errout_with_fd:
    close(fd);
  
  errout:
  
    printf("chrono_daemon: Terminating\n");
    return EXIT_FAILURE;
  }
  
  /****************************************************************************
   * Name: slcd_flush
   ****************************************************************************/
  
  static int slcd_flush(FAR struct lib_outstream_s *stream)
  {
    FAR struct slcd_chrono_s *priv = (FAR struct slcd_chrono_s *)stream;
    FAR const uint8_t *buffer;
    ssize_t nwritten;
    ssize_t remaining;
  
    /* Loop until all bytes were written (handling both partial and interrupted
     * writes).
     */
  
    remaining = stream->nput;
    buffer    = priv->buffer;
  
    while (remaining > 0)
      {
        nwritten = write(priv->fd, buffer, remaining);
        if (nwritten < 0)
          {
            int errcode = errno;
            printf("write failed: %d\n", errcode);
  
            if (errcode != EINTR)
              {
                exit(EXIT_FAILURE);
              }
          }
        else
          {
            remaining -= nwritten;
            buffer    += nwritten;
          }
      }
  
    /* Reset the stream */
  
    stream->nput = 0;
    return OK;
  }
  
  /****************************************************************************
   * Name: slcd_putc
   ****************************************************************************/
  
  static void slcd_putc(FAR struct lib_outstream_s *stream, int ch)
  {
    FAR struct slcd_chrono_s *priv = (FAR struct slcd_chrono_s *)stream;
  
    /* Write the character to the buffer */
  
    priv->buffer[stream->nput] = ch;
    stream->nput++;
    priv->buffer[stream->nput] = '\0';
  
    /* If the buffer is full, flush it */
  
    if (stream->nput >= CONFIG_EXAMPLES_SLCD_BUFSIZE)
      {
        slcd_flush(stream);
      }
  }
  
  /****************************************************************************
   * Name: slcd_puts
   ****************************************************************************/
  
  static void slcd_puts(FAR struct lib_outstream_s *outstream,
                        FAR const char *str)
  {
    for (; *str; str++)
      {
        slcd_put((int)*str, outstream);
      }
  }
  
  /****************************************************************************
   * chrono_main
   ****************************************************************************/
  
  int main(int argc, FAR char *argv[])
  {
    FAR struct slcd_chrono_s *priv = &g_slcd;
    FAR char str[8] = "00:00.0";
    int fd;
    int ret;
    long sec;
    long min;
  
    /* Create a thread to wait for the button events */
  
    ret = task_create("chrono_daemon", BUTTON_PRIORITY,
                      BUTTON_STACKSIZE, chrono_daemon, NULL);
    if (ret < 0)
      {
        int errcode = errno;
        printf("buttons_main: ERROR: Failed to start chrono_daemon: %d\n",
               errcode);
        return EXIT_FAILURE;
      }
  
    /* Open the SLCD device */
  
    printf("Opening %s for read/write access\n", SLCD_DEVNAME);
  
    fd = open(SLCD_DEVNAME, O_RDWR);
    if (fd < 0)
      {
        printf("Failed to open %s: %d\n", SLCD_DEVNAME, errno);
        goto errout;
      }
  
    /* Get the attributes of the SCLD device */
  
    ret = ioctl(fd, SLCDIOC_GETATTRIBUTES, (unsigned long)&priv->attr);
    if (ret < 0)
      {
        printf("ioctl(SLCDIOC_GETATTRIBUTES) failed: %d\n", errno);
        goto errout_with_fd;
      }
  
    /* Are we already initialized? */
  
    if (!priv->initialized)
      {
        /* Initialize the output stream */
  
        memset(priv, 0, sizeof(struct slcd_chrono_s));
        priv->stream.put   = slcd_putc;
  #ifdef CONFIG_STDIO_LINEBUFFER
        priv->stream.flush = slcd_flush;
  #endif
  
        /* Get the attributes of the SCLD device */
  
        ret = ioctl(fd, SLCDIOC_GETATTRIBUTES, (unsigned long)&priv->attr);
        if (ret < 0)
          {
            printf("ioctl(SLCDIOC_GETATTRIBUTES) failed: %d\n", errno);
            goto errout_with_fd;
          }
  
        printf("Attributes:\n");
        printf("  rows: %d columns: %d nbars: %d\n",
               priv->attr.nrows, priv->attr.ncolumns, priv->attr.nbars);
        printf("  max contrast: %d max brightness: %d\n",
               priv->attr.maxcontrast, priv->attr.maxbrightness);
  
        /* Home the cursor and clear the display */
  
        printf("Clear screen\n");
        slcd_encode(SLCDCODE_CLEAR, 0, &priv->stream);
        slcd_flush(&priv->stream);
  
        priv->initialized = true;
      }
  
    /* Save the file descriptor in a place where slcd_flush can find it */
  
    priv->fd = fd;
  
    /* Set the cursor to the beginning of the current row by homing the cursor
     * then going down as necessary, and erase to the end of the line.
     */
  
    slcd_encode(SLCDCODE_HOME, 0, &priv->stream);
    slcd_encode(SLCDCODE_ERASEEOL, 0, &priv->stream);
  
    priv->state = CHRONO_RESETED;
  
    for (; ; )
      {
        /* If the device is reset, show 00.. and assume it is initial time */
  
        if (priv->state == CHRONO_RESETED)
          {
            /* Copy the initial value */
  
            strncpy(str, "00:00.0", 7);
  
            /* Print the initial reset value */
  
            slcd_puts(&priv->stream, str);
            slcd_flush(&priv->stream);
  
            /* Move to stopped state to avoid wasting time here */
  
            priv->state = CHRONO_STOPPED;
          }
  
        /* If the device is stopped nothing to do here */
  
        if (priv->state == CHRONO_STOPPED)
          {
          }
  
        /* If the chronometer is running, get the elapsed time and how it */
  
        if (priv->state == CHRONO_RUNNING)
          {
            /* Get the current time */
  
            clock_gettime(CLOCK_MONOTONIC, &priv->ts_end);
  
            /* How many seconds passed from initial time? */
  
            sec = priv->ts_end.tv_sec - priv->ts_start.tv_sec;
  
            /* Get the amount of minutes */
  
            min = sec / 60;
  
            /* Get the remaining seconds */
  
            sec = sec % 60;
  
            sprintf(str, "%02ld:%02ld:%01ld", min, sec,
                    (priv->ts_end.tv_nsec / 100000000));
  
            /* Print it into LCD */
  
            slcd_encode(SLCDCODE_HOME, 0, &priv->stream);
            slcd_puts(&priv->stream, str);
            slcd_flush(&priv->stream);
          }
  
        /* usleep(1000); */
      }
  
    /* Normal exit */
  
    close(fd);
    return 0;
  
  errout_with_fd:
    close(priv->fd);
  errout:
    priv->initialized = false;
    exit(EXIT_FAILURE);
  }
  