LibrePilot/flight/PiOS/Common/pios_l3gd20.c

/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup PIOS_L3GD20 L3GD20 Functions
 * @brief Deals with the hardware interface to the 3-axis gyro
 * @{
 *
 * @file       pios_l3gd20.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
 * @brief      L3GD20 3-axis gyro chip
 * @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
 */

/* Project Includes */
#include "pios.h"

#if defined(PIOS_INCLUDE_L3GD20)

#include "fifo_buffer.h"

/* Global Variables */
enum pios_l3gd20_dev_magic {
	PIOS_L3GD20_DEV_MAGIC = 0x9d39bced,
};

#define PIOS_L3GD20_MAX_DOWNSAMPLE 2
struct l3gd20_dev {
	uint32_t spi_id;
	uint32_t slave_num;
	xQueueHandle queue;
	const struct pios_l3gd20_cfg * cfg;
	enum pios_l3gd20_filter bandwidth;
	enum pios_l3gd20_range range;
	enum pios_l3gd20_dev_magic magic;
};

//! Global structure for this device device
static struct l3gd20_dev * dev;

//! Private functions
static struct l3gd20_dev * PIOS_L3GD20_alloc(void);
static int32_t PIOS_L3GD20_Validate(struct l3gd20_dev * dev);
static void PIOS_L3GD20_Config(struct pios_l3gd20_cfg const * cfg);
static int32_t PIOS_L3GD20_SetReg(uint8_t address, uint8_t buffer);
static int32_t PIOS_L3GD20_GetReg(uint8_t address);
static int32_t PIOS_L3GD20_ClaimBus();
static int32_t PIOS_L3GD20_ClaimBusIsr();
static int32_t PIOS_L3GD20_ReleaseBus();

volatile bool l3gd20_configured = false;

/* Local Variables */
#define DEG_TO_RAD (M_PI / 180.0)

/**
 * @brief Allocate a new device
 */
static struct l3gd20_dev * PIOS_L3GD20_alloc(void)
{
	struct l3gd20_dev * l3gd20_dev;

	l3gd20_dev = (struct l3gd20_dev *)pvPortMalloc(sizeof(*l3gd20_dev));
	if (!l3gd20_dev) return (NULL);

	l3gd20_dev->magic = PIOS_L3GD20_DEV_MAGIC;

	l3gd20_dev->queue = xQueueCreate(PIOS_L3GD20_MAX_DOWNSAMPLE, sizeof(struct pios_l3gd20_data));
	if(l3gd20_dev->queue == NULL) {
		vPortFree(l3gd20_dev);
		return NULL;
	}

	return(l3gd20_dev);
}

/**
 * @brief Validate the handle to the spi device
 * @returns 0 for valid device or -1 otherwise
 */
static int32_t PIOS_L3GD20_Validate(struct l3gd20_dev * dev)
{
	if (dev == NULL) 
		return -1;
	if (dev->magic != PIOS_L3GD20_DEV_MAGIC)
		return -2;
	if (dev->spi_id == 0)
		return -3;
	return 0;
}

/**
 * @brief Initialize the MPU6050 3-axis gyro sensor.
 * @return none
 */
#include <pios_board_info.h>
int32_t PIOS_L3GD20_Init(uint32_t spi_id, uint32_t slave_num, const struct pios_l3gd20_cfg * cfg)
{
	dev = PIOS_L3GD20_alloc();
	if(dev == NULL)
		return -1;

	dev->spi_id = spi_id;
	dev->slave_num = slave_num;
	dev->cfg = cfg;

	/* Configure the MPU6050 Sensor */
	PIOS_L3GD20_Config(cfg);

	/* Set up EXTI */
	PIOS_EXTI_Init(cfg->exti_cfg);
	
	// An initial read is needed to get it running
	struct pios_l3gd20_data data;
	PIOS_L3GD20_ReadGyros(&data);

	return 0;
}

/**
 * @brief Initialize the L3GD20 3-axis gyro sensor
 * \return none
 * \param[in] PIOS_L3GD20_ConfigTypeDef struct to be used to configure sensor.
*
*/
static void PIOS_L3GD20_Config(struct pios_l3gd20_cfg const * cfg)
{
	// This register enables the channels and sets the bandwidth
	while(PIOS_L3GD20_SetReg(PIOS_L3GD20_CTRL_REG1, PIOS_L3GD20_CTRL1_FASTEST |
							 PIOS_L3GD20_CTRL1_PD | PIOS_L3GD20_CTRL1_ZEN |
							 PIOS_L3GD20_CTRL1_YEN | PIOS_L3GD20_CTRL1_XEN) != 0);
					   
	// Disable the high pass filters
	while(PIOS_L3GD20_SetReg(PIOS_L3GD20_CTRL_REG2, 0) != 0);
	// Set int2 to go high on data ready
	while(PIOS_L3GD20_SetReg(PIOS_L3GD20_CTRL_REG3, 0x08) != 0);
	// Select SPI interface, 500 deg/s, endianness?
	while(PIOS_L3GD20_SetRange(cfg->range) != 0);
	// Enable FIFO, disable HPF
	while(PIOS_L3GD20_SetReg(PIOS_L3GD20_CTRL_REG5, 0x40) != 0);
	// Fifo stream mode
	while(PIOS_L3GD20_SetReg(PIOS_L3GD20_FIFO_CTRL_REG, 0x40) != 0);
}

/**
 * @brief Sets the maximum range of the L3GD20
 * @returns 0 for success, -1 for invalid device, -2 if unable to set register
 */
int32_t PIOS_L3GD20_SetRange(enum pios_l3gd20_range range)
{
	if(PIOS_L3GD20_Validate(dev) != 0)
		return -1;

	dev->range = range;
	if(PIOS_L3GD20_SetReg(PIOS_L3GD20_CTRL_REG4, dev->range) != 0)
		return -2;
	
	return 0;
}

/**
 * @brief Claim the SPI bus for the accel communications and select this chip
 * @return 0 if successful, -1 for invalid device, -2 if unable to claim bus
 */
static int32_t PIOS_L3GD20_ClaimBus()
{
	if(PIOS_L3GD20_Validate(dev) != 0)
		return -1;

	if(PIOS_SPI_ClaimBus(dev->spi_id) != 0)
		return -2;

	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
 * @return 0 if successful, -1 for invalid device, -2 if unable to claim bus
 */
static int32_t PIOS_L3GD20_ClaimBusIsr()
{
	if(PIOS_L3GD20_Validate(dev) != 0)
		return -1;

	if(PIOS_SPI_ClaimBusISR(dev->spi_id) != 0)
		return -2;

	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, -1 for invalid device
 */
int32_t PIOS_L3GD20_ReleaseBus()
{
	if(PIOS_L3GD20_Validate(dev) != 0)
		return -1;

	PIOS_SPI_RC_PinSet(dev->spi_id,dev->slave_num,1);

	return PIOS_SPI_ReleaseBus(dev->spi_id);
}

/**
 * @brief Read a register from L3GD20
 * @returns The register value or -1 if failure to get bus
 * @param reg[in] Register address to be read
 */
static int32_t PIOS_L3GD20_GetReg(uint8_t reg)
{
	uint8_t data;

	if(PIOS_L3GD20_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_L3GD20_ReleaseBus();
	return data;
}

/**
 * @brief Writes one byte to the L3GD20
 * \param[in] reg Register address
 * \param[in] data Byte to write
 * \return 0 if operation was successful
 * \return -1 if unable to claim SPI bus
 * \return -2 if unable to claim i2c device
 */
static int32_t PIOS_L3GD20_SetReg(uint8_t reg, uint8_t data)
{
	if(PIOS_L3GD20_ClaimBus() != 0)
		return -1;
	
	PIOS_SPI_TransferByte(dev->spi_id, 0x7f & reg);
	PIOS_SPI_TransferByte(dev->spi_id, data);
	
	PIOS_L3GD20_ReleaseBus();
	
	return 0;
}

/**
 * @brief Read current X, Z, Y values (in that order)
 * \param[out] int16_t array of size 3 to store X, Z, and Y magnetometer readings
 * \returns The number of samples remaining in the fifo
 */
uint32_t l3gd20_irq = 0;
int32_t PIOS_L3GD20_ReadGyros(struct pios_l3gd20_data * data)
{
	uint8_t buf[7] = {PIOS_L3GD20_GYRO_X_OUT_LSB | 0x80 | 0x40, 0, 0, 0, 0, 0, 0};
	uint8_t rec[7];
	
	if(PIOS_L3GD20_ClaimBus() != 0)
		return -1;

	if(PIOS_SPI_TransferBlock(dev->spi_id, &buf[0], &rec[0], sizeof(buf), NULL) < 0) {
		PIOS_L3GD20_ReleaseBus();
		data->gyro_x = 0;
		data->gyro_y = 0;
		data->gyro_z = 0;
		data->temperature = 0;
		return -2;
	}
		
	PIOS_L3GD20_ReleaseBus();
	
	memcpy((uint8_t *) &(data->gyro_x), &rec[1], 6);
	data->temperature = PIOS_L3GD20_GetReg(PIOS_L3GD20_OUT_TEMP);
	
	return 0;
}

/**
 * @brief Read the identification bytes from the MPU6050 sensor
 * \return ID read from MPU6050 or -1 if failure
*/
int32_t PIOS_L3GD20_ReadID()
{
	int32_t l3gd20_id = PIOS_L3GD20_GetReg(PIOS_L3GD20_WHOAMI);
	if(l3gd20_id < 0)
		return -1;
	return l3gd20_id;
}

/**
 * \brief Reads the queue handle
 * \return Handle to the queue or null if invalid device
 */
xQueueHandle PIOS_L3GD20_GetQueue()
{
	if(PIOS_L3GD20_Validate(dev) != 0)
		return (xQueueHandle) NULL;

	return dev->queue;
}

float PIOS_L3GD20_GetScale() 
{
	if(PIOS_L3GD20_Validate(dev) != 0)
		return -1;

	switch (dev->range) {
		case PIOS_L3GD20_SCALE_250_DEG:
			return 0.00875f;
		case PIOS_L3GD20_SCALE_500_DEG:
			return 0.01750f;
		case PIOS_L3GD20_SCALE_2000_DEG:
			return 0.070f;
	}
	return 0;
}

/**
 * @brief Run self-test operation.
 * \return 0 if test succeeded
 * \return non-zero value if test succeeded
 */
uint8_t PIOS_L3GD20_Test(void)
{
	int32_t l3gd20_id = PIOS_L3GD20_ReadID();
	if(l3gd20_id < 0)
		return -1;

	uint8_t id = l3gd20_id;
	if(id == 0xD4)
		return 0;

	return -2;
}

/**
* @brief IRQ Handler.  Read all the data from onboard buffer
*/
bool PIOS_L3GD20_IRQHandler(void)
{
	l3gd20_irq++;

	struct pios_l3gd20_data data;
	uint8_t buf[7] = {PIOS_L3GD20_GYRO_X_OUT_LSB | 0x80 | 0x40, 0, 0, 0, 0, 0, 0};
	uint8_t rec[7];

	/* This code duplicates ReadGyros above but uses ClaimBusIsr */
	if(PIOS_L3GD20_ClaimBusIsr() != 0)
		return false;
	
	if(PIOS_SPI_TransferBlock(dev->spi_id, &buf[0], &rec[0], sizeof(buf), NULL) < 0) {
		PIOS_L3GD20_ReleaseBus();
		return false;
	}
	
	PIOS_L3GD20_ReleaseBus();
	
	memcpy((uint8_t *) &(data.gyro_x), &rec[1], 6);
	data.temperature = PIOS_L3GD20_GetReg(PIOS_L3GD20_OUT_TEMP);
	
	portBASE_TYPE xHigherPriorityTaskWoken;
	xQueueSendToBackFromISR(dev->queue, (void *) &data, &xHigherPriorityTaskWoken);
	
	return xHigherPriorityTaskWoken == pdTRUE;
}

#endif /* L3GD20 */

/**
 * @}
 * @}
 */