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
 */

#include "pios.h"
#include <pios_l3gd20.h>
#ifdef 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_GetRegISR(uint8_t address, bool *woken);
static int32_t PIOS_L3GD20_ClaimBus();
static int32_t PIOS_L3GD20_ClaimBusISR(bool *woken);
static int32_t PIOS_L3GD20_ReleaseBus();
static int32_t PIOS_L3GD20_ReleaseBusISR(bool *woken);

volatile bool l3gd20_configured = false;

/* Local Variables */

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

    l3gd20_dev = (struct l3gd20_dev *)pios_malloc(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 *vdev)
{
    if (vdev == NULL) {
        return -1;
    }
    if (vdev->magic != PIOS_L3GD20_DEV_MAGIC) {
        return -2;
    }
    if (vdev->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
 * @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 for invalid device, -2 if unable to claim bus
 */
static int32_t PIOS_L3GD20_ClaimBusISR(bool *woken)
{
    if (PIOS_L3GD20_Validate(dev) != 0) {
        return -1;
    }
    if (PIOS_SPI_ClaimBusISR(dev->spi_id, woken) != 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 Release the SPI bus for the accel communications and end the transaction
 * @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 for invalid device
 */
int32_t PIOS_L3GD20_ReleaseBusISR(bool *woken)
{
    if (PIOS_L3GD20_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 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 Read a register from L3GD20 in an ISR context
 * @param reg[in] Register address to be read
 * @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 The register value or -1 if failure to get bus
 */
static int32_t PIOS_L3GD20_GetRegISR(uint8_t reg, bool *woken)
{
    uint8_t data;

    if (PIOS_L3GD20_ClaimBusISR(woken) != 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_ReleaseBusISR(woken);
    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 EXTI IRQ Handler.  Read all the data from onboard buffer
 * @return a boolean to the EXTI IRQ Handler wrapper indicating if a
 *         higher priority task is now eligible to run
 */
bool PIOS_L3GD20_IRQHandler(void)
{
    bool woken     = false;
    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];

    l3gd20_irq++;

    /* This code duplicates ReadGyros above but uses ClaimBusIsr */
    if (PIOS_L3GD20_ClaimBusISR(&woken) != 0) {
        return woken;
    }

    if (PIOS_SPI_TransferBlock(dev->spi_id, &buf[0], &rec[0], sizeof(buf), NULL) < 0) {
        PIOS_L3GD20_ReleaseBusISR(&woken);
        return woken;
    }

    PIOS_L3GD20_ReleaseBusISR(&woken);

    memcpy((uint8_t *)&(data.gyro_x), &rec[1], 6);
    data.temperature = PIOS_L3GD20_GetRegISR(PIOS_L3GD20_OUT_TEMP, &woken);

    signed portBASE_TYPE higherPriorityTaskWoken;
    xQueueSendToBackFromISR(dev->queue, (void *)&data, &higherPriorityTaskWoken);

    return woken || higherPriorityTaskWoken == pdTRUE;
}

#endif /* PIOS_INCLUDE_L3GD20 */

/**
 * @}
 * @}
 */