1 files changed, 642 insertions, 0 deletions

diff --git a/lib/chibios/os/ex/devices/ST/l3gd20.c b/lib/chibios/os/ex/devices/ST/l3gd20.c
new file mode 100644
index 000000000..82f5d544d
--- /dev/null
+++ b/lib/chibios/os/ex/devices/ST/l3gd20.c
@@ -0,0 +1,642 @@
+/*
+    ChibiOS - Copyright (C) 2016..2019 Rocco Marco Guglielmi
+
+    This file is part of ChibiOS.
+
+    ChibiOS 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 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    l3gd20.c
+ * @brief   L3GD20 MEMS interface module code.
+ *
+ * @addtogroup L3GD20
+ * @ingroup EX_ST
+ * @{
+ */
+
+#include "hal.h"
+#include "l3gd20.h"
+
+/*===========================================================================*/
+/* Driver local definitions.                                                 */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables.                                                */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local variables and types.                                         */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions.                                                   */
+/*===========================================================================*/
+
+#if (L3GD20_USE_SPI) || defined(__DOXYGEN__)
+/**
+ * @brief   Reads a generic register value using SPI.
+ * @pre     The SPI interface must be initialized and the driver started.
+ *
+ * @param[in] spip      pointer to the SPI interface
+ * @param[in] reg       starting register address
+ * @param[in] n         number of consecutive registers to read
+ * @param[in] b         pointer to an output buffer.
+ */
+static void l3gd20SPIReadRegister(SPIDriver *spip, uint8_t reg,  size_t n,
+                                     uint8_t* b) {
+  uint8_t cmd;
+  (n == 1) ? (cmd = reg | L3GD20_RW) : (cmd = reg | L3GD20_RW | L3GD20_MS);
+  spiSelect(spip);
+  spiSend(spip, 1, &cmd);
+  spiReceive(spip, n, b);
+  spiUnselect(spip);
+}
+
+/**
+ * @brief   Writes a value into a generic register using SPI.
+ * @pre     The SPI interface must be initialized and the driver started.
+ *
+ * @param[in] spip      pointer to the SPI interface
+ * @param[in] reg       starting register address
+ * @param[in] n         number of adjacent registers to write
+ * @param[in] b         pointer to a buffer of values.
+ */
+static void l3gd20SPIWriteRegister(SPIDriver *spip, uint8_t reg, size_t n,
+                                   uint8_t* b) {
+  uint8_t cmd;
+  (n == 1) ? (cmd = reg) : (cmd = reg | L3GD20_MS);
+  spiSelect(spip);
+  spiSend(spip, 1, &cmd);
+  spiSend(spip, n, b);
+  spiUnselect(spip);
+}
+#endif /* L3GD20_USE_SPI */
+
+/**
+ * @brief   Return the number of axes of the BaseGyroscope.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ *
+ * @return              the number of axes.
+ */
+static size_t gyro_get_axes_number(void *ip) {
+  (void)ip;
+  
+  return L3GD20_GYRO_NUMBER_OF_AXES;
+}
+
+/**
+ * @brief   Retrieves raw data from the BaseGyroscope.
+ * @note    This data is retrieved from MEMS register without any algebraical
+ *          manipulation.
+ * @note    The axes array must be at least the same size of the
+ *          BaseGyroscope axes number.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ * @param[out] axes     a buffer which would be filled with raw data.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ */
+static msg_t gyro_read_raw(void *ip, int32_t axes[L3GD20_GYRO_NUMBER_OF_AXES]) {
+  L3GD20Driver* devp;
+  int16_t tmp;
+  uint8_t i, buff [2 * L3GD20_GYRO_NUMBER_OF_AXES];
+  msg_t msg = MSG_OK;
+  
+  osalDbgCheck((ip != NULL) && (axes != NULL));
+
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+  
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_read_raw(), invalid state");
+#if L3GD20_USE_SPI
+  osalDbgAssert((devp->config->spip->state == SPI_READY),
+                "gyro_read_raw(), channel not ready");
+                
+#if     L3GD20_SHARED_SPI
+  spiAcquireBus(devp->config->spip);
+  spiStart(devp->config->spip,
+           devp->config->spicfg);
+#endif /* L3GD20_SHARED_SPI */
+
+  l3gd20SPIReadRegister(devp->config->spip, L3GD20_AD_OUT_X_L,
+                        L3GD20_GYRO_NUMBER_OF_AXES * 2, buff);
+
+#if     L3GD20_SHARED_SPI
+  spiReleaseBus(devp->config->spip);
+#endif /* L3GD20_SHARED_SPI */
+#endif /* L3GD20_USE_SPI */
+
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+      tmp = buff[2 * i] + (buff[2 * i + 1] << 8);
+      axes[i] = (int32_t)tmp;
+    }
+  return msg;
+}
+
+/**
+ * @brief   Retrieves cooked data from the BaseGyroscope.
+ * @note    This data is manipulated according to the formula
+ *          cooked = (raw * sensitivity) - bias.
+ * @note    Final data is expressed as DPS.
+ * @note    The axes array must be at least the same size of the
+ *          BaseGyroscope axes number.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ * @param[out] axes     a buffer which would be filled with cooked data.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ */
+static msg_t gyro_read_cooked(void *ip, float axes[]) {
+  L3GD20Driver* devp;
+  uint32_t i;
+  int32_t raw[L3GD20_GYRO_NUMBER_OF_AXES];
+  msg_t msg;
+
+  osalDbgCheck((ip != NULL) && (axes != NULL));
+
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+  
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_read_cooked(), invalid state");
+
+  msg = gyro_read_raw(ip, raw);
+  for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++){
+    axes[i] = (raw[i] * devp->gyrosensitivity[i]) - devp->gyrobias[i];
+  }
+  return msg;
+}
+
+/**
+ * @brief   Samples bias values for the BaseGyroscope.
+ * @note    The L3GD20 shall not be moved during the whole procedure.
+ * @note    After this function internal bias is automatically updated.
+ * @note    The behavior of this function depends on @p L3GD20_BIAS_ACQ_TIMES
+ *          and @p L3GD20_BIAS_SETTLING_US.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ */
+static msg_t gyro_sample_bias(void *ip) {
+  L3GD20Driver* devp;
+  uint32_t i, j;
+  int32_t raw[L3GD20_GYRO_NUMBER_OF_AXES];
+  int32_t buff[L3GD20_GYRO_NUMBER_OF_AXES] = {0, 0, 0};
+  msg_t msg;
+        
+  osalDbgCheck(ip != NULL);
+
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+  
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_sample_bias(), invalid state");
+#if L3GD20_USE_SPI
+  osalDbgAssert((devp->config->spip->state == SPI_READY),
+                "gyro_sample_bias(), channel not ready");
+#endif
+
+  for(i = 0; i < L3GD20_BIAS_ACQ_TIMES; i++){
+    msg = gyro_read_raw(ip, raw);
+                if(msg != MSG_OK)
+                        return msg;
+    for(j = 0; j < L3GD20_GYRO_NUMBER_OF_AXES; j++){
+      buff[j] += raw[j];
+    }
+    osalThreadSleepMicroseconds(L3GD20_BIAS_SETTLING_US);
+  }
+
+  for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++){
+    devp->gyrobias[i] = (buff[i] / L3GD20_BIAS_ACQ_TIMES);
+    devp->gyrobias[i] *= devp->gyrosensitivity[i];
+  }
+  return msg;
+}
+
+/**
+ * @brief   Set bias values for the BaseGyroscope.
+ * @note    Bias must be expressed as DPS.
+ * @note    The bias buffer must be at least the same size of the BaseGyroscope
+ *          axes number.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ * @param[in] bp        a buffer which contains biases.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ */
+static msg_t gyro_set_bias(void *ip, float *bp) {
+  L3GD20Driver* devp;
+  uint32_t i;
+  msg_t msg = MSG_OK;
+  
+  osalDbgCheck((ip != NULL) && (bp != NULL));
+  
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+  
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_set_bias(), invalid state");
+  
+  for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+    devp->gyrobias[i] = bp[i];
+  }
+  return msg;
+}
+
+/**
+ * @brief   Reset bias values for the BaseGyroscope.
+ * @note    Default biases value are obtained from device datasheet when
+ *          available otherwise they are considered zero.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ */
+static msg_t gyro_reset_bias(void *ip) {
+  L3GD20Driver* devp;
+  uint32_t i;
+  msg_t msg = MSG_OK;
+
+  osalDbgCheck(ip != NULL);
+  
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+  
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_reset_bias(), invalid state");
+
+  for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++)
+    devp->gyrobias[i] = L3GD20_GYRO_BIAS;
+  return msg;
+}
+
+/**
+ * @brief   Set sensitivity values for the BaseGyroscope.
+ * @note    Sensitivity must be expressed as DPS/LSB.
+ * @note    The sensitivity buffer must be at least the same size of the
+ *          BaseGyroscope axes number.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ * @param[in] sp        a buffer which contains sensitivities.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ */
+static msg_t gyro_set_sensivity(void *ip, float *sp) {
+  L3GD20Driver* devp;
+  uint32_t i;
+  msg_t msg = MSG_OK;
+  
+  osalDbgCheck((ip != NULL) && (sp !=NULL));
+
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_set_sensivity(), invalid state");
+  
+  for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+    devp->gyrosensitivity[i] = sp[i];
+  }
+  return msg;
+}
+
+/**
+ * @brief   Reset sensitivity values for the BaseGyroscope.
+ * @note    Default sensitivities value are obtained from device datasheet.
+ *
+ * @param[in] ip        pointer to @p BaseGyroscope interface.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ * @retval MSG_RESET    otherwise.
+ */
+static msg_t gyro_reset_sensivity(void *ip) {
+  L3GD20Driver* devp;
+  uint32_t i;
+  msg_t msg = MSG_OK;
+  
+  osalDbgCheck(ip != NULL);
+
+  /* Getting parent instance pointer.*/
+  devp = objGetInstance(L3GD20Driver*, (BaseGyroscope*)ip);
+
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_reset_sensivity(), invalid state");
+
+  if(devp->config->gyrofullscale == L3GD20_FS_250DPS)
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++)
+      devp->gyrosensitivity[i] = L3GD20_GYRO_SENS_250DPS;
+  else if(devp->config->gyrofullscale == L3GD20_FS_500DPS)
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++)
+        devp->gyrosensitivity[i] = L3GD20_GYRO_SENS_500DPS;
+  else if(devp->config->gyrofullscale == L3GD20_FS_2000DPS)
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++)
+        devp->gyrosensitivity[i] = L3GD20_GYRO_SENS_2000DPS;
+  else {
+    osalDbgAssert(FALSE, "gyro_reset_sensivity(), full scale issue");
+    return MSG_RESET;
+  }
+  return msg;
+}
+
+/**
+ * @brief   Changes the L3GD20Driver gyroscope fullscale value.
+ * @note    This function also rescale sensitivities and biases based on
+ *          previous and next fullscale value.
+ * @note    A recalibration is highly suggested after calling this function.
+ *
+ * @param[in] devp      pointer to @p BaseGyroscope interface.
+ * @param[in] fs        new fullscale value.
+ *
+ * @return              The operation status.
+ * @retval MSG_OK       if the function succeeded.
+ * @retval MSG_RESET    otherwise.
+ */
+static msg_t gyro_set_full_scale(L3GD20Driver *devp, l3gd20_fs_t fs) {
+  float newfs, scale;
+  uint8_t i, cr;
+  msg_t msg = MSG_OK;
+
+  osalDbgCheck(devp != NULL);
+
+  osalDbgAssert((devp->state == L3GD20_READY),
+                "gyro_set_full_scale(), invalid state");
+#if L3GD20_USE_SPI
+  osalDbgAssert((devp->config->spip->state == SPI_READY),
+                "gyro_set_full_scale(), channel not ready");
+#endif
+
+  if(fs == L3GD20_FS_250DPS) {
+    newfs = L3GD20_250DPS;
+  }
+  else if(fs == L3GD20_FS_500DPS) {
+    newfs = L3GD20_500DPS;
+  }
+  else if(fs == L3GD20_FS_2000DPS) {
+    newfs = L3GD20_2000DPS;
+  }
+  else {
+    return MSG_RESET;
+  }
+
+  if(newfs != devp->gyrofullscale) {
+    scale = newfs / devp->gyrofullscale;
+    devp->gyrofullscale = newfs;
+
+#if L3GD20_USE_SPI
+#if     L3GD20_SHARED_SPI
+                spiAcquireBus(devp->config->spip);
+                spiStart(devp->config->spip,
+                                                 devp->config->spicfg);
+#endif /* L3GD20_SHARED_SPI */
+
+    /* Updating register.*/
+    l3gd20SPIReadRegister(devp->config->spip,
+                          L3GD20_AD_CTRL_REG4, 1, &cr);
+
+#if     L3GD20_SHARED_SPI
+                spiReleaseBus(devp->config->spip);
+#endif /* L3GD20_SHARED_SPI */
+#endif /* L3GD20_USE_SPI */
+    cr &= ~(L3GD20_CTRL_REG4_FS_MASK);
+    cr |= fs;
+
+#if L3GD20_USE_SPI
+#if     L3GD20_SHARED_SPI
+                spiAcquireBus(devp->config->spip);
+                spiStart(devp->config->spip,
+                                                 devp->config->spicfg);
+#endif /* L3GD20_SHARED_SPI */
+
+    l3gd20SPIWriteRegister(devp->config->spip,
+                           L3GD20_AD_CTRL_REG4, 1, &cr);
+#if     L3GD20_SHARED_SPI
+                spiReleaseBus(devp->config->spip);
+#endif /* L3GD20_SHARED_SPI */
+#endif /* L3GD20_USE_SPI */
+
+    /* Scaling sensitivity and bias. Re-calibration is suggested anyway. */
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+      devp->gyrosensitivity[i] *= scale;
+      devp->gyrobias[i] *= scale;
+    }
+  }
+  return msg;
+}
+
+static const struct L3GD20VMT vmt_device = {
+  (size_t)0,
+  gyro_set_full_scale
+};
+
+static const struct BaseGyroscopeVMT vmt_gyroscope = {
+  sizeof(struct L3GD20VMT*),
+  gyro_get_axes_number, gyro_read_raw, gyro_read_cooked,
+  gyro_sample_bias, gyro_set_bias, gyro_reset_bias,
+  gyro_set_sensivity, gyro_reset_sensivity
+};
+
+/*===========================================================================*/
+/* Driver exported functions.                                                */
+/*===========================================================================*/
+
+/**
+ * @brief   Initializes an instance.
+ *
+ * @param[out] devp     pointer to the @p L3GD20Driver object
+ *
+ * @init
+ */
+void l3gd20ObjectInit(L3GD20Driver *devp) {
+  devp->vmt = &vmt_device;
+  devp->gyro_if.vmt = &vmt_gyroscope;
+  
+  devp->config = NULL;
+
+  devp->state  = L3GD20_STOP;
+}
+
+/**
+ * @brief   Configures and activates L3GD20 Complex Driver peripheral.
+ *
+ * @param[in] devp      pointer to the @p L3GD20Driver object
+ * @param[in] config    pointer to the @p L3GD20Config object
+ *
+ * @api
+ */
+void l3gd20Start(L3GD20Driver *devp, const L3GD20Config *config) {
+  uint32_t i;
+  uint8_t cr[5] = {0, 0, 0, 0, 0};
+  osalDbgCheck((devp != NULL) && (config != NULL));
+
+  osalDbgAssert((devp->state == L3GD20_STOP) || (devp->state == L3GD20_READY),
+              "l3gd20Start(), invalid state");
+
+  devp->config = config;
+             
+  /* Control register 1 configuration block.*/
+  {
+    cr[0] = L3GD20_CTRL_REG1_XEN | L3GD20_CTRL_REG1_YEN | 
+          L3GD20_CTRL_REG1_ZEN | L3GD20_CTRL_REG1_PD |
+          devp->config->gyrooutputdatarate;
+#if L3GD20_USE_ADVANCED || defined(__DOXYGEN__)
+    cr[0] |= devp->config->gyrobandwidth;
+#endif
+  }
+  
+  /* Control register 2 configuration block.*/
+  {
+#if L3GD20_USE_ADVANCED || defined(__DOXYGEN__)
+  if(devp->config->gyrohpmode != L3GD20_HPM_BYPASSED)
+    cr[1] = devp->config->gyrohpmode | devp->config->gyrohpconfiguration;
+#endif
+  }
+  
+  /* Control register 4 configuration block.*/
+  {
+    cr[3] = devp->config->gyrofullscale;
+#if L3GD20_USE_ADVANCED || defined(__DOXYGEN__)
+    cr[3] |= devp->config->gyroblockdataupdate |
+             devp->config->gyroendianness;
+#endif
+  }
+  
+  /* Control register 5 configuration block.*/
+  {    
+#if L3GD20_USE_ADVANCED || defined(__DOXYGEN__)
+  if((devp->config->gyrohpmode != L3GD20_HPM_BYPASSED)) {
+    cr[4] = L3GD20_CTRL_REG5_HPEN;
+    if(devp->config->gyrolp2mode != L3GD20_LP2M_BYPASSED) {
+      cr[4] |= L3GD20_CTRL_REG5_INT1_SEL1 |
+               L3GD20_CTRL_REG5_OUT_SEL1;
+    }
+    else {
+      cr[4] |= L3GD20_CTRL_REG5_INT1_SEL0 |
+               L3GD20_CTRL_REG5_OUT_SEL0; 
+    }
+  }
+#endif
+  }
+
+#if L3GD20_USE_SPI
+#if     L3GD20_SHARED_SPI
+  spiAcquireBus(devp->config->spip);
+#endif /* L3GD20_SHARED_SPI */
+  spiStart(devp->config->spip,
+           devp->config->spicfg);
+           
+  l3gd20SPIWriteRegister(devp->config->spip, L3GD20_AD_CTRL_REG1, 
+                         5, cr);
+#if     L3GD20_SHARED_SPI
+  spiReleaseBus(devp->config->spip);
+#endif /* L3GD20_SHARED_SPI */
+#endif /* L3GD20_USE_SPI */
+  
+  /* Storing sensitivity information according to full scale.*/
+  if(devp->config->gyrofullscale == L3GD20_FS_250DPS) {
+    devp->gyrofullscale = L3GD20_250DPS;
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+      if (devp->config->gyrosensitivity == NULL)
+        devp->gyrosensitivity[i] = L3GD20_GYRO_SENS_250DPS;
+      else
+        devp->gyrosensitivity[i] = devp->config->gyrosensitivity[i];
+    }
+  }
+  else if(devp->config->gyrofullscale == L3GD20_FS_500DPS) {
+    devp->gyrofullscale = L3GD20_500DPS;
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+      if (devp->config->gyrosensitivity == NULL)
+        devp->gyrosensitivity[i] = L3GD20_GYRO_SENS_500DPS;
+      else
+        devp->gyrosensitivity[i] = devp->config->gyrosensitivity[i];
+    }
+  }
+  else if(devp->config->gyrofullscale == L3GD20_FS_2000DPS) {
+    devp->gyrofullscale = L3GD20_2000DPS;
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+      if (devp->config->gyrosensitivity == NULL)
+        devp->gyrosensitivity[i] = L3GD20_GYRO_SENS_2000DPS;
+      else
+        devp->gyrosensitivity[i] = devp->config->gyrosensitivity[i];
+    }
+  }
+  else
+    osalDbgAssert(FALSE, "l3gd20Start(), full scale issue");
+
+  /* Storing bias information.*/
+  if(devp->config->gyrobias != NULL) {
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++) {
+      devp->gyrobias[i] = devp->config->gyrobias[i];
+    }
+  }
+  else {
+    for(i = 0; i < L3GD20_GYRO_NUMBER_OF_AXES; i++)
+      devp->gyrobias[i] = L3GD20_GYRO_BIAS;
+  }
+  
+  /* This is the Gyroscope transient recovery time.*/
+  osalThreadSleepMilliseconds(10);
+
+  devp->state = L3GD20_READY;
+} 
+
+/**
+ * @brief   Deactivates the L3GD20 Complex Driver peripheral.
+ *
+ * @param[in] devp       pointer to the @p L3GD20Driver object
+ *
+ * @api
+ */
+void l3gd20Stop(L3GD20Driver *devp) {
+  uint8_t cr1;
+  osalDbgCheck(devp != NULL);
+
+  osalDbgAssert((devp->state == L3GD20_STOP) || (devp->state == L3GD20_READY),
+                "l3gd20Stop(), invalid state");
+
+  if (devp->state == L3GD20_READY) {
+    /* Disabling all axes and enabling power down mode.*/
+    cr1 = 0;
+    
+#if L3GD20_USE_SPI
+#if     L3GD20_SHARED_SPI
+    spiAcquireBus(devp->config->spip);
+    spiStart(devp->config->spip,
+             devp->config->spicfg);
+#endif /* L3GD20_SHARED_SPI */
+
+    l3gd20SPIWriteRegister(devp->config->spip, L3GD20_AD_CTRL_REG1, 
+                           1, &cr1);
+    spiStop(devp->config->spip);
+    
+#if     L3GD20_SHARED_SPI
+    spiReleaseBus(devp->config->spip);
+#endif /* L3GD20_SHARED_SPI */ 
+#endif /* L3GD20_USE_SPI */
+  }                      
+  devp->state = L3GD20_STOP;
+}
+/** @} */