/****************************************************************************
 * drivers/sensors/lis331dl.c
 *
 *   Copyright (C) 2011 Uros Platise. All rights reserved.
 *
 *   Authors: Uros Platise <uros.platise@isotel.eu>
 *
 * 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 <assert.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>

#include <nuttx/kmalloc.h>
#include <nuttx/sensors/lis331dl.h>

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/
/* LIS331DL Internal Registers **********************************************/

#define ST_LIS331DL_WHOAMI          0x0F    /* who am I register */
#define ST_LIS331DL_WHOAMI_VALUE    0x3B    /* Valid result is 0x3B */

#define ST_LIS331DL_CTRL_REG1       0x20
#define ST_LIS331DL_CR1_DR          0x80    /* Data-rate selection 0: 100 Hz, 1: 400 Hz */
#define ST_LIS331DL_CR1_PD          0x40    /* Active Mode (1) / Power-down (0) */
#define ST_LIS331DL_CR1_FS          0x20    /* Full Scale (1) +-9g or Normal Scale (0) +-2g */
#define ST_LIS331DL_CR1_ST          0x18    /* Self test enable */
#define ST_LIS331DL_CR1_ZEN         0x04    /* Z-Axis Enable */
#define ST_LIS331DL_CR1_YEN         0x02    /* Y-Axis Enable */
#define ST_LIS331DL_CR1_XEN         0x01    /* X-Axis Enable */

#define ST_LIS331DL_CTRL_REG2       0x21
#define ST_LIS331DL_CTRL_REG3       0x22

#define ST_LIS331DL_HP_FILTER_RESET 0x23

#define ST_LIS331DL_STATUS_REG      0x27    /* Status Register */
#define ST_LIS331DL_SR_ZYXOR        0x80    /* OR'ed X,Y and Z data over-run  */
#define ST_LIS331DL_SR_ZOR          0x40    /* individual data over-run ... */
#define ST_LIS331DL_SR_YOR          0x20
#define ST_LIS331DL_SR_XOR          0x10
#define ST_LIS331DL_SR_ZYXDA        0x08    /* OR'ed X,Y and Z data available */
#define ST_LIS331DL_SR_ZDA          0x04    /* individual data available ... */
#define ST_LIS331DL_SR_YDA          0x02
#define ST_LIS331DL_SR_XDA          0x01

#define ST_LIS331DL_OUT_X           0x29
#define ST_LIS331DL_OUT_Y           0x2B
#define ST_LIS331DL_OUT_Z           0x2D

/****************************************************************************
 * Private Data Types
 ****************************************************************************/

struct lis331dl_dev_s
{
  struct i2c_dev_s        *i2c;
  uint8_t                  address;
  struct lis331dl_vector_s a;
  uint8_t                  cr1;
  uint8_t                  cr2;
  uint8_t                  cr3;
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * LIS331DL Access with range check
 *
 * Input Parameters:
 *   dev     LIS331 DL Private Structure
 *   subaddr LIS331 Sub Address
 *   buf     Pointer to buffer, either for read or write access
 *   length  When >0 it denotes read access, when <0 it denotes write access
 *           of -length
 *
 * Returned Value:
 *   Returns OK on success or errno is set.
 *
 ****************************************************************************/

static int lis331dl_access(FAR struct lis331dl_dev_s *dev, uint8_t subaddr,
                           FAR uint8_t *buf, int length)
{
  uint16_t flags = 0;
  int retval;

  if (length > 0)
    {
      flags = I2C_M_READ;
    }
  else
    {
      flags = I2C_M_NORESTART;
      length = -length;
    }

  /* Check valid address ranges and set auto address increment flag */

  if (subaddr == 0x0f)
    {
      if (length > 1)
        {
          length = 1;
        }
    }
  else if (subaddr >= 0x20 && subaddr < 0x24)
    {
      if (length > (0x24 - subaddr))
        {
          length = 0x24 - subaddr;
        }
    }
  else if (subaddr >= 0x27 && subaddr < 0x2e)
    {
      if (length > (0x2e - subaddr))
        {
          length = 0x2e - subaddr;
        }
    }
  else if (subaddr >= 0x30 && subaddr < 0x40)
    {
      if (length > (0x40 - subaddr))
        {
          length = 0x40 - subaddr;
        }
    }
  else
    {
      errno = EFAULT;
      return ERROR;
    }

  if (length > 1)
    {
      subaddr |= 0x80;
    }

    /* Create message and send */

    struct i2c_msg_s msgv[2] =
    {
      {
        .addr   = dev->address,
        .flags  = 0,
        .buffer = &subaddr,
        .length = 1
      },
      {
        .addr   = dev->address,
        .flags  = flags,
        .buffer = buf,
        .length = length
      }
    };

  if ((retval = I2C_TRANSFER(dev->i2c, msgv, 2)) == OK)
    {
      return length;
    }

  return retval;
}

static int lis331dl_readregs(FAR struct lis331dl_dev_s *dev)
{
  if (lis331dl_access(dev, ST_LIS331DL_CTRL_REG1, &dev->cr1, 3) != 3)
    {
      return ERROR;
    }

  return OK;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

FAR struct lis331dl_dev_s *lis331dl_init(FAR struct i2c_dev_s *i2c,
                                         uint16_t address)
{
  FAR struct lis331dl_dev_s * dev;
  uint8_t retval;

  ASSERT(i2c);
  ASSERT(address);

  dev = kmalloc(sizeof(struct lis331dl_dev_s));
  if (dev == NULL)
    {
      errno = ENOMEM;
      return NULL;
    }

  memset(dev, 0, sizeof(struct lis331dl_dev_s));
  dev->i2c     = i2c;
  dev->address = address;

  /* Probe device */

  if (lis331dl_access(dev, ST_LIS331DL_WHOAMI, &retval, 1) > 0)
    {
      /* Check chip identification, in the future several more compatible parts
       * may be added here.
       */

      if (retval == ST_LIS331DL_WHOAMI_VALUE)
        {
          /* Copy LIS331DL registers to our private structure and power-up device */

          if (lis331dl_readregs(dev)==OK && lis331dl_powerup(dev) == OK)
            {
              /* Normal exit point */

              errno = 0;
              return dev;
            }

          retval = errno;
        }

      /* Otherwise, we mark an invalid device found at given address */

      retval = ENODEV;
    }
  else
    {
      /* No response at given address is marked as */

      retval = EFAULT;
    }

  /* Error exit */

  kfree(dev);
  errno = retval;
  return NULL;
}

int lis331dl_deinit(FAR struct lis331dl_dev_s * dev)
{
  ASSERT(dev);

  lis331dl_powerdown(dev);
  kfree(dev);

  return OK;
}

int lis331dl_powerup(FAR struct lis331dl_dev_s * dev)
{
  dev->cr1 = ST_LIS331DL_CR1_PD |
    ST_LIS331DL_CR1_ZEN | ST_LIS331DL_CR1_YEN | ST_LIS331DL_CR1_XEN;
  dev->cr2 = 0;
  dev->cr3 = 0;

  if (lis331dl_access(dev, ST_LIS331DL_CTRL_REG1, &dev->cr1, -3) == 3)
    {
      return OK;
    }

  return ERROR;
}

int lis331dl_powerdown(FAR struct lis331dl_dev_s * dev)
{
  dev->cr1 = ST_LIS331DL_CR1_ZEN | ST_LIS331DL_CR1_YEN | ST_LIS331DL_CR1_XEN;
  dev->cr2 = 0;
  dev->cr3 = 0;

  if (lis331dl_access(dev, ST_LIS331DL_CTRL_REG1, &dev->cr1, -3) == 3)
   {
     return OK;
   }

  return ERROR;
}

int lis331dl_setconversion(FAR struct lis331dl_dev_s * dev, bool full, bool fast)
{
  dev->cr1 = ST_LIS331DL_CR1_PD |
    (full ? ST_LIS331DL_CR1_FS : 0) | (fast ? ST_LIS331DL_CR1_DR : 0) |
    ST_LIS331DL_CR1_ZEN | ST_LIS331DL_CR1_YEN | ST_LIS331DL_CR1_XEN;

  if (lis331dl_access(dev, ST_LIS331DL_CTRL_REG1, &dev->cr1, -1) == 1)
    {
      return OK;
    }

  return ERROR;
}

int lis331dl_getprecision(FAR struct lis331dl_dev_s * dev)
{
  if (dev->cr1 & ST_LIS331DL_CR1_FS)
    {
      return 9200/127;   /* typ. 9.2g full scale */
    }

  return 2300/127;       /* typ. 2.3g full scale */
}

int lis331dl_getsamplerate(FAR struct lis331dl_dev_s * dev)
{
  if (dev->cr1 & ST_LIS331DL_CR1_DR)
    {
      return 400;
    }

  return 100;
}

FAR const struct lis331dl_vector_s *
lis331dl_getreadings(FAR struct lis331dl_dev_s * dev)
{
  uint8_t retval[7];

  ASSERT(dev);

  if (lis331dl_access(dev, ST_LIS331DL_STATUS_REG, retval, 7) == 7)
    {
      /* If result is not yet ready, return NULL */

      if (!(retval[0] & ST_LIS331DL_SR_ZYXDA))
        {
          errno = EAGAIN;
          return NULL;
        }

      dev->a.x = retval[2];
      dev->a.y = retval[4];
      dev->a.z = retval[6];
      return &dev->a;
    }

  return NULL;
}