text: /****************************************************************************
   * drivers/power/powerled.c
   * Upper-half, character driver for high power LED driver.
   *
   *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
   *   Author: Mateusz Szafoni <raiden00@railab.me>
   *
   * 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/types.h>
  #include <stdint.h>
  #include <unistd.h>
  #include <semaphore.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <nuttx/arch.h>
  #include <nuttx/semaphore.h>
  #include <nuttx/fs/fs.h>
  #include <nuttx/power/powerled.h>
  
  #include <nuttx/irq.h>
  
  /****************************************************************************
   * Private Function Prototypes
   ****************************************************************************/
  
  static int     powerled_open(FAR struct file *filep);
  static int     powerled_close(FAR struct file *filep);
  static int     powerled_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  static const struct file_operations powerled_fops =
  {
    powerled_open,                /* open */
    powerled_close,               /* close */
    NULL,                         /* read */
    NULL,                         /* write */
    NULL,                         /* seek */
    powerled_ioctl                /* ioctl */
  #ifndef CONFIG_DISABLE_POLL
    , NULL                        /* poll */
  #endif
  #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
    , NULL                        /* unlink */
  #endif
  };
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: powerled_open
   *
   * Description:
   *   This function is called whenever the POWERLED device is opened.
   *
   ****************************************************************************/
  
  static int powerled_open(FAR struct file *filep)
  {
    FAR struct inode      *inode = filep->f_inode;
    FAR struct powerled_dev_s *dev   = inode->i_private;
    uint8_t                tmp;
    int                    ret   = OK;
  
    /* If the port is the middle of closing, wait until the close is finished */
  
    if (sem_wait(&dev->closesem) != OK)
      {
        ret = -errno;
      }
    else
      {
        /* Increment the count of references to the device.  If this the first
         * time that the driver has been opened for this device, then initialize
         * the device.
         */
  
        tmp = dev->ocount + 1;
        if (tmp == 0)
          {
            /* More than 255 opens; uint8_t overflows to zero */
  
            ret = -EMFILE;
          }
        else
          {
            /* Check if this is the first time that the driver has been opened. */
  
            if (tmp == 1)
              {
                /* Yes.. perform one time hardware initialization. */
  
                irqstate_t flags = enter_critical_section();
                ret = dev->ops->setup(dev);
                if (ret == OK)
                  {
                    /* Save the new open count on success */
  
                    dev->ocount = tmp;
                  }
  
                leave_critical_section(flags);
              }
          }
  
        sem_post(&dev->closesem);
      }
  
    return OK;
  }
  
  /****************************************************************************
   * Name: powerled_close
   *
   * Description:
   *   This routine is called when the POWERLED device is closed.
   *   It waits for the last remaining data to be sent.
   *
   ****************************************************************************/
  
  static int powerled_close(FAR struct file *filep)
  {
    FAR struct inode     *inode = filep->f_inode;
    FAR struct powerled_dev_s *dev   = inode->i_private;
    irqstate_t            flags;
    int                   ret = OK;
  
    if (sem_wait(&dev->closesem) != OK)
      {
        ret = -errno;
      }
    else
      {
        /* Decrement the references to the driver.  If the reference count will
         * decrement to 0, then uninitialize the driver.
         */
  
        if (dev->ocount > 1)
          {
            dev->ocount--;
            sem_post(&dev->closesem);
          }
        else
          {
            /* There are no more references to the port */
  
            dev->ocount = 0;
  
            /* Free the IRQ and disable the POWERLED device */
  
            flags = enter_critical_section();       /* Disable interrupts */
            dev->ops->shutdown(dev);               /* Disable the POWERLED */
            leave_critical_section(flags);
  
            sem_post(&dev->closesem);
          }
      }
  
    return ret;
  }
  
  /****************************************************************************
   * Name: powerled_ioctl
  ****************************************************************************/
  
  static int powerled_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
  {
    FAR struct inode *inode    = filep->f_inode;
    FAR struct powerled_dev_s *dev = inode->i_private;
    FAR struct powerled_s *powerled    = (FAR struct powerled_s *)dev->priv;
    int ret;
  
    switch (cmd)
      {
        case PWRIOC_START:
          {
  
            /* Allow powerled start only when limits set and structure is locked */
  
            if (powerled->limits.lock == false ||
                powerled->limits.current <= 0)
              {
                pwrerr("ERROR: powerled limits must be set"
                       " and locked before start\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* Check powerled mode */
  
            if (powerled->opmode != POWERLED_OPMODE_CONTINUOUS &&
                powerled->opmode != POWERLED_OPMODE_FLASH)
              {
                pwrerr("ERROR: unsupported powerled mode!");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* Finally, call start from lower-half driver */
  
            ret = dev->ops->start(dev);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_START failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_STOP:
          {
            ret = dev->ops->stop(dev);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_STOP failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_SET_MODE:
          {
            uint8_t mode = ((uint8_t)arg);
  
            ret = dev->ops->mode_set(dev, mode);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_SET_MODE failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_SET_LIMITS:
          {
            FAR struct powerled_limits_s *limits =
              (FAR struct powerled_limits_s *)((uintptr_t)arg);
  
            if (powerled->limits.lock == true)
              {
                pwrerr("ERROR: PWRRLED limits locked!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* NOTE: this call must set the powerled_limits_s structure */
  
            ret = dev->ops->limits_set(dev, limits);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_SET_LIMITS failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_GET_STATE:
          {
            FAR struct powerled_state_s *state =
              (FAR struct powerled_state_s *)((uintptr_t)arg);
  
            ret = dev->ops->state_get(dev, state);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_GET_STATE failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_SET_FAULT:
          {
            uint8_t fault = ((uint8_t)arg);
  
            ret = dev->ops->fault_set(dev, fault);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_SET_FAULT failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_GET_FAULT:
          {
            uint8_t *fault = ((uint8_t*)arg);
  
            ret = dev->ops->fault_get(dev, fault);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_GET_FAULT failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_CLEAN_FAULT:
          {
            uint8_t fault = ((uint8_t)arg);
  
            ret = dev->ops->fault_clean(dev, fault);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_CLEAN_FAULT failed %d\n", ret);
              }
            break;
          }
  
        case PWRIOC_SET_PARAMS:
          {
            FAR struct powerled_params_s *params =
              (FAR struct powerled_params_s *)((uintptr_t)arg);
  
            if (powerled->param.lock == true)
              {
                pwrerr("ERROR: powerled params locked!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            if (params->brightness < 0.0 || params->brightness > 100.0 ||
                params->frequency < 0.0 || params->duty < 0.0 || params->duty > 100.0)
              {
                pwrerr("ERROR: powerled invalid parameters %f %f %f\n",
                       params->brightness, params->frequency, params->duty);
  
                ret = -EPERM;
                goto errout;
              }
  
            ret = dev->ops->params_set(dev, params);
            if (ret != OK)
              {
                pwrerr("ERROR: PWRIOC_SET_PARAMS failed %d\n", ret);
              }
            break;
          }
  
        default:
          {
            pwrinfo("Forwarding unrecognized cmd: %d arg: %ld\n", cmd, arg);
            ret = dev->ops->ioctl(dev, cmd, arg);
            break;
          }
      }
  
  errout:
    return ret;
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: powerled_register
   ****************************************************************************/
  
  int powerled_register(FAR const char *path, FAR struct powerled_dev_s *dev, FAR void *lower)
  {
    int ret;
  
    DEBUGASSERT(path != NULL && dev != NULL && lower != NULL);
    DEBUGASSERT(dev->ops != NULL);
  
    /* For safety reason, when some necessary low-level logic is not provided,
     * system should fail before low-level hardware initialization, so:
     *   - all ops are checked here, before character driver registration
     *   - all ops must be provided, even if not used
     */
  
    DEBUGASSERT(dev->ops->setup != NULL);
    DEBUGASSERT(dev->ops->shutdown != NULL);
    DEBUGASSERT(dev->ops->stop != NULL);
    DEBUGASSERT(dev->ops->start != NULL);
    DEBUGASSERT(dev->ops->params_set != NULL);
    DEBUGASSERT(dev->ops->mode_set != NULL);
    DEBUGASSERT(dev->ops->limits_set != NULL);
    DEBUGASSERT(dev->ops->fault_set != NULL);
    DEBUGASSERT(dev->ops->state_get != NULL);
    DEBUGASSERT(dev->ops->fault_get != NULL);
    DEBUGASSERT(dev->ops->fault_clean != NULL);
    DEBUGASSERT(dev->ops->ioctl != NULL);
  
    /* Initialize the HRTIM device structure */
  
    dev->ocount = 0;
  
    /* Initialize semaphores */
  
    sem_init(&dev->closesem, 0, 1);
  
    /* Connect POWERLED driver with lower level interface */
  
    dev->lower = lower;
  
    /* Register the POWERLED character driver */
  
    ret = register_driver(path, &powerled_fops, 0444, dev);
    if (ret < 0)
      {
        sem_destroy(&dev->closesem);
      }
  
    return ret;
  }
  