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LibrePilot/flight/pios/common/pios_bma180.c

565 lines
14 KiB
C

/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_BMA180 BMA180 Functions
* @brief Deals with the hardware interface to the BMA180 3-axis accelerometer
* @{
*
* @file pios_bma180.h
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
* @brief PiOS BMA180 digital accelerometer driver.
* - Driver for the BMA180 digital accelerometer on the SPI bus.
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* This program 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.
*
* This program 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, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pios.h"
#include <pios_bma180.h>
#ifdef PIOS_INCLUDE_BMA180
#include "fifo_buffer.h"
enum pios_bma180_dev_magic {
PIOS_BMA180_DEV_MAGIC = 0xcbb93755,
};
#define PIOS_BMA180_MAX_DOWNSAMPLE 10
struct bma180_dev {
uint32_t spi_id;
uint32_t slave_num;
int16_t buffer[PIOS_BMA180_MAX_DOWNSAMPLE * sizeof(struct pios_bma180_data)];
t_fifo_buffer fifo;
const struct pios_bma180_cfg *cfg;
enum bma180_bandwidth bandwidth;
enum bma180_range range;
enum pios_bma180_dev_magic magic;
};
// ! Global structure for this device device
static struct bma180_dev *dev;
// ! Private functions
static struct bma180_dev *PIOS_BMA180_alloc(void);
static int32_t PIOS_BMA180_Validate(struct bma180_dev *dev);
static int32_t PIOS_BMA180_GetReg(uint8_t reg);
static int32_t PIOS_BMA180_SetReg(uint8_t reg, uint8_t data);
static int32_t PIOS_BMA180_SelectBW(enum bma180_bandwidth bw);
static int32_t PIOS_BMA180_SetRange(enum bma180_range range);
static int32_t PIOS_BMA180_Config();
static int32_t PIOS_BMA180_EnableIrq();
#define GRAV 9.81f
/**
* @brief Allocate a new device
*/
static struct bma180_dev *PIOS_BMA180_alloc(void)
{
struct bma180_dev *bma180_dev;
bma180_dev = (struct bma180_dev *)pios_malloc(sizeof(*bma180_dev));
if (!bma180_dev) {
return NULL;
}
fifoBuf_init(&bma180_dev->fifo, (uint8_t *)bma180_dev->buffer, sizeof(bma180_dev->buffer));
bma180_dev->magic = PIOS_BMA180_DEV_MAGIC;
return bma180_dev;
}
/**
* @brief Validate the handle to the spi device
* @returns 0 for valid device or -1 otherwise
*/
static int32_t PIOS_BMA180_Validate(struct bma180_dev *vdev)
{
if (vdev == NULL) {
return -1;
}
if (vdev->magic != PIOS_BMA180_DEV_MAGIC) {
return -2;
}
if (vdev->spi_id == 0) {
return -3;
}
return 0;
}
/**
* @brief Initialize with good default settings
* @returns 0 for success, -1 for failure
*/
int32_t PIOS_BMA180_Init(uint32_t spi_id, uint32_t slave_num, const struct pios_bma180_cfg *cfg)
{
dev = PIOS_BMA180_alloc();
if (dev == NULL) {
return -1;
}
dev->spi_id = spi_id;
dev->slave_num = slave_num;
dev->cfg = cfg;
if (PIOS_BMA180_Config() < 0) {
return -1;
}
PIOS_DELAY_WaituS(50);
PIOS_EXTI_Init(dev->cfg->exti_cfg);
while (PIOS_BMA180_EnableIrq() != 0) {
;
}
return 0;
}
/**
* @brief Claim the SPI bus for the accel communications and select this chip
* @return 0 if successful, -1 if unable to claim bus
*/
int32_t PIOS_BMA180_ClaimBus()
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
if (PIOS_SPI_ClaimBus(dev->spi_id) != 0) {
return -1;
}
PIOS_SPI_RC_PinSet(dev->spi_id, dev->slave_num, 0);
return 0;
}
/**
* @brief Claim the SPI bus for the accel communications and select this chip. Call from an ISR.
* @param woken[in,out] If non-NULL, will be set to true if woken was false and a higher priority
* task has is now eligible to run, else unchanged
* @return 0 if successful, -1 if unable to claim bus
*/
int32_t PIOS_BMA180_ClaimBusISR(bool *woken)
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
if (PIOS_SPI_ClaimBusISR(dev->spi_id, woken) != 0) {
return -1;
}
PIOS_SPI_RC_PinSet(dev->spi_id, dev->slave_num, 0);
return 0;
}
/**
* @brief Release the SPI bus for the accel communications and end the transaction
* @return 0 if successful
*/
int32_t PIOS_BMA180_ReleaseBus()
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
PIOS_SPI_RC_PinSet(dev->spi_id, dev->slave_num, 1);
return PIOS_SPI_ReleaseBus(dev->spi_id);
}
/**
* @brief Release the SPI bus for the accel communications and end the transaction. Call from an ISR
* @param woken[in,out] If non-NULL, will be set to true if woken was false and a higher priority
* task has is now eligible to run, else unchanged
* @return 0 if successful
*/
int32_t PIOS_BMA180_ReleaseBusISR(bool *woken)
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
PIOS_SPI_RC_PinSet(dev->spi_id, dev->slave_num, 1);
return PIOS_SPI_ReleaseBusISR(dev->spi_id, woken);
}
/**
* @brief Read a register from BMA180
* @returns The register value or -1 if failure to get bus
* @param reg[in] Register address to be read
*/
int32_t PIOS_BMA180_GetReg(uint8_t reg)
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
uint8_t data;
if (PIOS_BMA180_ClaimBus() != 0) {
return -1;
}
PIOS_SPI_TransferByte(dev->spi_id, (0x80 | reg)); // request byte
data = PIOS_SPI_TransferByte(dev->spi_id, 0); // receive response
PIOS_BMA180_ReleaseBus();
return data;
}
/**
* @brief Write a BMA180 register. EEPROM must be unlocked before calling this function.
* @return none
* @param reg[in] address of register to be written
* @param data[in] data that is to be written to register
*/
int32_t PIOS_BMA180_SetReg(uint8_t reg, uint8_t data)
{
if (PIOS_BMA180_ClaimBus() != 0) {
return -1;
}
PIOS_SPI_TransferByte(dev->spi_id, 0x7f & reg);
PIOS_SPI_TransferByte(dev->spi_id, data);
PIOS_BMA180_ReleaseBus();
return 0;
}
static int32_t PIOS_BMA180_EnableEeprom()
{
// Enable EEPROM writing
int32_t byte = PIOS_BMA180_GetReg(BMA_CTRREG0);
if (byte < 0) {
return -1;
}
byte |= 0x10; // Set bit 4
if (PIOS_BMA180_SetReg(BMA_CTRREG0, (uint8_t)byte) < 0) { // Have to set ee_w to
return -1;
}
return 0;
}
static int32_t PIOS_BMA180_DisableEeprom()
{
// Enable EEPROM writing
int32_t byte = PIOS_BMA180_GetReg(BMA_CTRREG0);
if (byte < 0) {
return -1;
}
byte |= 0x10; // Set bit 4
if (PIOS_BMA180_SetReg(BMA_CTRREG0, (uint8_t)byte) < 0) { // Have to set ee_w to
return -1;
}
return 0;
}
/**
* @brief Set the default register settings
* @return 0 if successful, -1 if not
*/
static int32_t PIOS_BMA180_Config()
{
/*
0x35 = 0x81 //smp-skip = 1 for less interrupts
0x33 = 0x81 //shadow-dis = 1, update MSB and LSB synchronously
0x27 = 0x01 //dis-i2c
0x21 = 0x02 //new_data_int = 1
*/
PIOS_DELAY_WaituS(20);
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
while (PIOS_BMA180_EnableEeprom() != 0) {
;
}
while (PIOS_BMA180_SetReg(BMA_RESET, BMA_RESET_CODE) != 0) {
;
}
while (PIOS_BMA180_SetReg(BMA_OFFSET_LSB1, 0x81) != 0) {
;
}
while (PIOS_BMA180_SetReg(BMA_GAIN_Y, 0x81) != 0) {
;
}
while (PIOS_BMA180_SetReg(BMA_CTRREG3, 0xFF) != 0) {
;
}
while (PIOS_BMA180_SelectBW(dev->cfg->bandwidth) != 0) {
;
}
while (PIOS_BMA180_SetRange(dev->cfg->range) != 0) {
;
}
while (PIOS_BMA180_DisableEeprom() != 0) {
;
}
return 0;
}
/**
* @brief Select the bandwidth the digital filter pass allows.
* @return 0 if successful, -1 if not
* @param rate[in] Bandwidth setting to be used
*
* EEPROM must be write-enabled before calling this function.
*/
static int32_t PIOS_BMA180_SelectBW(enum bma180_bandwidth bw)
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
dev->bandwidth = bw;
uint8_t reg;
reg = PIOS_BMA180_GetReg(BMA_BW_ADDR);
reg = (reg & ~BMA_BW_MASK) | ((bw << BMA_BW_SHIFT) & BMA_BW_MASK);
return PIOS_BMA180_SetReg(BMA_BW_ADDR, reg);
}
/**
* @brief Select the full scale acceleration range.
* @return 0 if successful, -1 if not
* @param rate[in] Range setting to be used
*
*/
static int32_t PIOS_BMA180_SetRange(enum bma180_range new_range)
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
uint8_t reg;
dev->range = new_range;
reg = PIOS_BMA180_GetReg(BMA_RANGE_ADDR);
reg = (reg & ~BMA_RANGE_MASK) | ((dev->range << BMA_RANGE_SHIFT) & BMA_RANGE_MASK);
return PIOS_BMA180_SetReg(BMA_RANGE_ADDR, reg);
}
static int32_t PIOS_BMA180_EnableIrq()
{
if (PIOS_BMA180_EnableEeprom() < 0) {
return -1;
}
if (PIOS_BMA180_SetReg(BMA_CTRREG3, BMA_NEW_DAT_INT) < 0) {
return -1;
}
if (PIOS_BMA180_DisableEeprom() < 0) {
return -1;
}
return 0;
}
/**
* @brief Read a single set of values from the x y z channels
* @param[out] data Int16 array of (x,y,z) sensor values
* @returns 0 if successful
* @retval -1 unable to claim bus
* @retval -2 unable to transfer data
*/
int32_t PIOS_BMA180_ReadAccels(struct pios_bma180_data *data)
{
// To save memory use same buffer for in and out but offset by
// a byte
uint8_t buf[7] = { BMA_X_LSB_ADDR | 0x80, 0, 0, 0, 0, 0 };
uint8_t rec[7] = { 0, 0, 0, 0, 0, 0 };
if (PIOS_BMA180_ClaimBus() != 0) {
return -1;
}
if (PIOS_SPI_TransferBlock(dev->spi_id, &buf[0], &rec[0], 7, NULL) != 0) {
return -2;
}
PIOS_BMA180_ReleaseBus();
// | MSB | LSB | 0 | new_data |
data->x = ((rec[2] << 8) | rec[1]);
data->y = ((rec[4] << 8) | rec[3]);
data->z = ((rec[6] << 8) | rec[5]);
data->x /= 4;
data->y /= 4;
data->z /= 4;
return 0; // return number of remaining entries
}
/**
* @brief Returns the scale the BMA180 chip is using
* @return Scale (m / s^2) / LSB
*/
float PIOS_BMA180_GetScale()
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
switch (dev->cfg->range) {
case BMA_RANGE_1G:
return GRAV / 8192.0f;
case BMA_RANGE_1_5G:
return GRAV / 5460.0f;
case BMA_RANGE_2G:
return GRAV / 4096.0f;
case BMA_RANGE_3G:
return GRAV / 2730.0f;
case BMA_RANGE_4G:
return GRAV / 2048.0f;
case BMA_RANGE_8G:
return GRAV / 1024.0f;
case BMA_RANGE_16G:
return GRAV / 512.0f;
}
return 0;
}
/**
* @brief Get data from fifo
* @param [out] buffer pointer to a @ref pios_bma180_data structure to receive data
* @return 0 for success, -1 for failure (no data available)
*/
int32_t PIOS_BMA180_ReadFifo(struct pios_bma180_data *buffer)
{
if (PIOS_BMA180_Validate(dev) != 0) {
return -1;
}
if (fifoBuf_getUsed(&dev->fifo) < sizeof(*buffer)) {
return -1;
}
fifoBuf_getData(&dev->fifo, (uint8_t *)buffer, sizeof(*buffer));
return 0;
}
/**
* @brief Test SPI and chip functionality by reading chip ID register
* @return 0 if success, -1 if failure.
*
*/
int32_t PIOS_BMA180_Test()
{
// Read chip ID then version ID
uint8_t buf[3] = { 0x80 | BMA_CHIPID_ADDR, 0, 0 };
uint8_t rec[3] = { 0, 0, 0 };
int32_t retval;
if (PIOS_BMA180_ClaimBus() != 0) {
return -1;
}
retval = PIOS_SPI_TransferBlock(dev->spi_id, &buf[0], &rec[0], sizeof(buf), NULL);
PIOS_BMA180_ReleaseBus();
if (retval != 0) {
return -2;
}
struct pios_bma180_data data;
if (PIOS_BMA180_ReadAccels(&data) != 0) {
return -3;
}
if (rec[1] != 0x3) {
return -4;
}
if (rec[2] < 0x12) {
return -5;
}
return 0;
}
/**
* @brief EXTI IRQ Handler. Read data from the BMA180 FIFO and push onto a local fifo.
* @return a boolean to the EXTI IRQ Handler wrapper indicating if a
* higher priority task is now eligible to run
*/
int32_t bma180_irqs = 0;
bool PIOS_BMA180_IRQHandler(void)
{
bool woken = false;
static const uint8_t pios_bma180_req_buf[7] = { BMA_X_LSB_ADDR | 0x80, 0, 0, 0, 0, 0 };
uint8_t pios_bma180_dmabuf[8];
bma180_irqs++;
// If we can't get the bus then just move on for efficiency
if (PIOS_BMA180_ClaimBusISR(&woken) != 0) {
return woken; // Something else is using bus, miss this data
}
PIOS_SPI_TransferBlock(dev->spi_id, pios_bma180_req_buf, (uint8_t *)pios_bma180_dmabuf,
sizeof(pios_bma180_dmabuf), NULL);
// TODO: Make this conversion depend on configuration scale
struct pios_bma180_data data;
// Don't release bus till data has copied
PIOS_BMA180_ReleaseBusISR(&woken);
// Must not return before releasing bus
if (fifoBuf_getFree(&dev->fifo) < sizeof(data)) {
return woken;
}
// Bottom two bits indicate new data and are constant zeros. Don't right
// shift because it drops sign bit
data.x = ((pios_bma180_dmabuf[2] << 8) | pios_bma180_dmabuf[1]);
data.y = ((pios_bma180_dmabuf[4] << 8) | pios_bma180_dmabuf[3]);
data.z = ((pios_bma180_dmabuf[6] << 8) | pios_bma180_dmabuf[5]);
data.x /= 4;
data.y /= 4;
data.z /= 4;
data.temperature = pios_bma180_dmabuf[7];
fifoBuf_putData(&dev->fifo, (uint8_t *)&data, sizeof(data));
return woken;
}
#endif /* PIOS_INCLUDE_BMA180 */
/**
* @}
* @}
*/