text: /****************************************************************************
   * drivers/power/smps.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.
   *
   ****************************************************************************/
  
  /* Upper-half, character driver for SMPS (switched-mode power supply) */
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <sys/types.h>
  #include <stdint.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <assert.h>
  #include <errno.h>
  #include <debug.h>
  
  #include <nuttx/arch.h>
  #include <nuttx/fs/fs.h>
  #include <nuttx/power/smps.h>
  
  #include <nuttx/irq.h>
  
  /****************************************************************************
   * Private Function Prototypes
   ****************************************************************************/
  
  static int     smps_open(FAR struct file *filep);
  static int     smps_close(FAR struct file *filep);
  static ssize_t smps_read(FAR struct file *filep, FAR char *buffer,
                           size_t buflen);
  static ssize_t smps_write(FAR struct file *filep, FAR const char *buffer,
                            size_t buflen);
  static int     smps_ioctl(FAR struct file *filep, int cmd,
                            unsigned long arg);
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  static const struct file_operations smps_fops =
  {
    smps_open,                    /* open */
    smps_close,                   /* close */
    smps_read,                    /* read */
    smps_write,                   /* write */
    NULL,                         /* seek */
    smps_ioctl,                   /* ioctl */
    NULL                          /* poll */
  #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
    , NULL                        /* unlink */
  #endif
  };
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: smps_open
   *
   * Description:
   *   This function is called whenever the SMPS device is opened.
   *
   ****************************************************************************/
  
  static int smps_open(FAR struct file *filep)
  {
    FAR struct inode      *inode = filep->f_inode;
    FAR struct smps_dev_s *dev   = inode->i_private;
    uint8_t                tmp;
    int                    ret;
  
    /* If the port is the middle of closing, wait until the close is finished */
  
    ret = nxsem_wait(&dev->closesem);
    if (ret >= 0)
      {
        /* 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);
              }
          }
  
        nxsem_post(&dev->closesem);
      }
  
    return OK;
  }
  
  /****************************************************************************
   * Name: smps_close
   *
   * Description:
   *   This routine is called when the SMPS device is closed.
   *   It waits for the last remaining data to be sent.
   *
   ****************************************************************************/
  
  static int smps_close(FAR struct file *filep)
  {
    FAR struct inode     *inode  = filep->f_inode;
    FAR struct smps_dev_s *dev   = inode->i_private;
    irqstate_t            flags;
    int                   ret;
  
    ret = nxsem_wait(&dev->closesem);
    if (ret >= 0)
      {
        /* Decrement the references to the driver.  If the reference count will
         * decrement to 0, then uninitialize the driver.
         */
  
        if (dev->ocount > 1)
          {
            dev->ocount--;
            nxsem_post(&dev->closesem);
          }
        else
          {
            /* There are no more references to the port */
  
            dev->ocount = 0;
  
            /* Free the IRQ and disable the SMPS device */
  
            flags = enter_critical_section();      /* Disable interrupts */
            dev->ops->shutdown(dev);               /* Disable the SMPS */
            leave_critical_section(flags);
  
            nxsem_post(&dev->closesem);
          }
      }
  
    return ret;
  }
  
  /****************************************************************************
   * Name: smps_read
   ****************************************************************************/
  
  static ssize_t smps_read(FAR struct file *filep, FAR char *buffer,
                           size_t buflen)
  {
    return 1;
  }
  
  /****************************************************************************
   * Name: smps_write
   ****************************************************************************/
  
  static ssize_t smps_write(FAR struct file *filep, FAR const char *buffer,
                            size_t buflen)
  {
    return 1;
  }
  
  /****************************************************************************
   * Name: smps_ioctl
   ****************************************************************************/
  
  static int smps_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
  {
    FAR struct inode *inode    = filep->f_inode;
    FAR struct smps_dev_s *dev = inode->i_private;
    FAR struct smps_s *smps    = (FAR struct smps_s *)dev->priv;
    int ret;
  
    switch (cmd)
      {
        case PWRIOC_START:
          {
            /* Allow SMPS start only when some limits available
             * and structure is locked.
             * REVISIT: not sure if it is needed here
             */
  
            if ((smps->limits.lock == false) ||
                (smps->limits.v_in <= 0 && smps->limits.v_out <= 0 &&
                 smps->limits.i_in <= 0 && smps->limits.i_out <= 0 &&
                 smps->limits.p_in <= 0 && smps->limits.p_out <= 0))
              {
                pwrerr("ERROR: SMPS limits data must be set"
                       " and locked before SMPS start\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* Check SMPS mode */
  
            if (smps->opmode == SMPS_OPMODE_INIT)
              {
                pwrerr("ERROR: SMPS operation mode not specified\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* When constan current mode, then output current must be
             * provided
             */
  
            if (smps->opmode == SMPS_OPMODE_CC && smps->param.i_out <= 0)
              {
                pwrerr("ERROR: CC selected but i_out not specified!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* When constan voltage mode, then output voltage must be
             * provided
             */
  
            if (smps->opmode == SMPS_OPMODE_CV && smps->param.v_out <= 0)
              {
                pwrerr("ERROR: CV selected but v_out not specified!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* When constan power mode, then output power must be provided */
  
            if (smps->opmode == SMPS_OPMODE_CP && smps->param.p_out <= 0)
              {
                pwrerr("ERROR: CP selected but p_out not specified!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* REVISIT: something else ?? */
  
            /* 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 smps_limits_s *limits =
              (FAR struct smps_limits_s *)((uintptr_t)arg);
  
            if (smps->limits.lock == true)
              {
                pwrerr("ERROR: SMPS limits locked!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* NOTE: this call must set the smps_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 smps_state_s *state =
              (FAR struct smps_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:
          {
            FAR uint8_t *fault = ((FAR 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 smps_params_s *params =
              (FAR struct smps_params_s *)((uintptr_t)arg);
  
            if (smps->param.lock == true)
              {
                pwrerr("ERROR: SMPS params locked!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            if ((smps->limits.lock == false) ||
                (smps->limits.v_in <= 0 && smps->limits.v_out <= 0 &&
                 smps->limits.i_in <= 0 && smps->limits.i_out <= 0 &&
                 smps->limits.p_in <= 0 && smps->limits.p_out <= 0))
              {
                pwrerr("ERROR: limits must be set prior to params!\n");
  
                ret = -EPERM;
                goto errout;
              }
  
            /* Check output voltage configuration */
  
            if (smps->limits.v_out > 0 && params->v_out > smps->limits.v_out)
              {
                pwrerr("ERROR: params->v_out > limits.v_out: %.2f > %.2f\n",
                       params->v_out, smps->limits.v_out);
  
                ret = -EPERM;
                goto errout;
              }
  
            /* Check output current configuration */
  
            if (smps->limits.i_out > 0 && params->i_out > smps->limits.i_out)
              {
                pwrerr("ERROR: params->i_out > limits.i_out: %.2f > %.2f\n",
                       params->i_out, smps->limits.i_out);
  
                ret = -EPERM;
                goto errout;
              }
  
            /* Check output power configuration */
  
            if (smps->limits.p_out > 0 && params->p_out > smps->limits.p_out)
              {
                pwrerr("ERROR: params->p_out > limits.p_out: %.2f > %.2f\n",
                       params->p_out, smps->limits.p_out);
  
                ret = -EPERM;
                goto errout;
              }
  
            /* TODO: limits */
  
            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: smps_register
   ****************************************************************************/
  
  int smps_register(FAR const char *path, FAR struct smps_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 SMPS device structure */
  
    dev->ocount = 0;
  
    /* Initialize semaphores */
  
    nxsem_init(&dev->closesem, 0, 1);
  
    /* Connect SMPS driver with lower level interface */
  
    dev->lower = lower;
  
    /* Register the SMPS character driver */
  
    ret = register_driver(path, &smps_fops, 0666, dev);
    if (ret < 0)
      {
        nxsem_destroy(&dev->closesem);
      }
  
    return ret;
  }
  