tinySA/os/various/devices_lib/accel/lis302dl.c

/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/RT is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file    lis302dl.c
 * @brief   LIS302DL MEMS interface module through SPI code.
 *
 * @addtogroup lis302dl
 * @{
 */

#include "ch.h"
#include "hal.h"
#include "lis302dl.h"

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables.                                                   */
/*===========================================================================*/

static uint8_t txbuf[2];
static uint8_t rxbuf[2];

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   Reads a register value.
 * @pre     The SPI interface must be initialized and the driver started.
 *
 * @param[in] spip      pointer to the SPI initerface
 * @param[in] reg       register number
 * @return              The register value.
 */
uint8_t lis302dlReadRegister(SPIDriver *spip, uint8_t reg) {

  spiSelect(spip);
  txbuf[0] = 0x80 | reg;
  txbuf[1] = 0xff;
  spiExchange(spip, 2, txbuf, rxbuf);
  spiUnselect(spip);
  return rxbuf[1];
}

/**
 * @brief   Writes a value into a register.
 * @pre     The SPI interface must be initialized and the driver started.
 *
 * @param[in] spip      pointer to the SPI initerface
 * @param[in] reg       register number
 * @param[in] value     the value to be written
 */
void lis302dlWriteRegister(SPIDriver *spip, uint8_t reg, uint8_t value) {

  switch (reg) {
  default:
    /* Reserved register must not be written, according to the datasheet
       this could permanently damage the device.*/
    chDbgAssert(FALSE, "lis302dlWriteRegister(), #1", "reserved register");
  case LIS302DL_WHO_AM_I:
  case LIS302DL_HP_FILTER_RESET:
  case LIS302DL_STATUS_REG:
  case LIS302DL_OUTX:
  case LIS302DL_OUTY:
  case LIS302DL_OUTZ:
  case LIS302DL_FF_WU_SRC1:
  case LIS302DL_FF_WU_SRC2:
  case LIS302DL_CLICK_SRC:
    /* Read only registers cannot be written, the command is ignored.*/
    return;
  case LIS302DL_CTRL_REG1:
  case LIS302DL_CTRL_REG2:
  case LIS302DL_CTRL_REG3:
  case LIS302DL_FF_WU_CFG1:
  case LIS302DL_FF_WU_THS1:
  case LIS302DL_FF_WU_DURATION1:
  case LIS302DL_FF_WU_CFG2:
  case LIS302DL_FF_WU_THS2:
  case LIS302DL_FF_WU_DURATION2:
  case LIS302DL_CLICK_CFG:
  case LIS302DL_CLICK_THSY_X:
  case LIS302DL_CLICK_THSZ:
  case LIS302DL_CLICK_TIMELIMIT:
  case LIS302DL_CLICK_LATENCY:
  case LIS302DL_CLICK_WINDOW:
    spiSelect(spip);
    txbuf[0] = reg;
    txbuf[1] = value;
    spiSend(spip, 2, txbuf);
    spiUnselect(spip);
  }
}

/** @} */