/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup PIOS_HMC5883 HMC5883 Functions
 * @brief Deals with the hardware interface to the magnetometers
 * @{
 * @file       pios_hmc5883.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
 * @brief      HMC5883 Magnetic Sensor Functions from AHRS
 * @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_HMC5883)

/* Global Variables */

/* Local Types */

/* Local Variables */
volatile bool pios_hmc5883_data_ready;

static int32_t PIOS_HMC5883_Config(const struct pios_hmc5883_cfg * cfg);
static int32_t PIOS_HMC5883_Read(uint8_t address, uint8_t * buffer, uint8_t len);
static int32_t PIOS_HMC5883_Write(uint8_t address, uint8_t buffer);

static const struct pios_hmc5883_cfg * dev_cfg;

/**
 * @brief Initialize the HMC5883 magnetometer sensor.
 * @return none
 */
void PIOS_HMC5883_Init(const struct pios_hmc5883_cfg * cfg)
{
	dev_cfg = cfg; // store config before enabling interrupt

	PIOS_EXTI_Init(cfg->exti_cfg);
	
	int32_t val = PIOS_HMC5883_Config(cfg);
	
	PIOS_Assert(val == 0);
	
	pios_hmc5883_data_ready = false;
}

/**
 * @brief Initialize the HMC5883 magnetometer sensor
 * \return none
 * \param[in] PIOS_HMC5883_ConfigTypeDef struct to be used to configure sensor.
 *
 * CTRL_REGA: Control Register A
 * Read Write
 * Default value: 0x10
 * 7:5  0   These bits must be cleared for correct operation.
 * 4:2 DO2-DO0: Data Output Rate Bits
 *             DO2 |  DO1 |  DO0 |   Minimum Data Output Rate (Hz)
 *            ------------------------------------------------------
 *              0  |  0   |  0   |            0.75
 *              0  |  0   |  1   |            1.5
 *              0  |  1   |  0   |            3
 *              0  |  1   |  1   |            7.5
 *              1  |  0   |  0   |           15 (default)
 *              1  |  0   |  1   |           30
 *              1  |  1   |  0   |           75
 *              1  |  1   |  1   |           Not Used
 * 1:0 MS1-MS0: Measurement Configuration Bits
 *             MS1 | MS0 |   MODE
 *            ------------------------------
 *              0  |  0   |  Normal
 *              0  |  1   |  Positive Bias
 *              1  |  0   |  Negative Bias
 *              1  |  1   |  Not Used
 *
 * CTRL_REGB: Control RegisterB
 * Read Write
 * Default value: 0x20
 * 7:5 GN2-GN0: Gain Configuration Bits.
 *             GN2 |  GN1 |  GN0 |   Mag Input   | Gain       | Output Range
 *                 |      |      |  Range[Ga]    | [LSB/mGa]  |
 *            ------------------------------------------------------
 *              0  |  0   |  0   |  ±0.88Ga      |   1370     | 0xF800–0x07FF (-2048:2047)
 *              0  |  0   |  1   |  ±1.3Ga (def) |   1090     | 0xF800–0x07FF (-2048:2047)
 *              0  |  1   |  0   |  ±1.9Ga       |   820      | 0xF800–0x07FF (-2048:2047)
 *              0  |  1   |  1   |  ±2.5Ga       |   660      | 0xF800–0x07FF (-2048:2047)
 *              1  |  0   |  0   |  ±4.0Ga       |   440      | 0xF800–0x07FF (-2048:2047)
 *              1  |  0   |  1   |  ±4.7Ga       |   390      | 0xF800–0x07FF (-2048:2047)
 *              1  |  1   |  0   |  ±5.6Ga       |   330      | 0xF800–0x07FF (-2048:2047)
 *              1  |  1   |  1   |  ±8.1Ga       |   230      | 0xF800–0x07FF (-2048:2047)
 *                               |Not recommended|
 *
 * 4:0 CRB4-CRB: 0 This bit must be cleared for correct operation.
 *
 * _MODE_REG: Mode Register
 * Read Write
 * Default value: 0x02
 * 7:2  0   These bits must be cleared for correct operation.
 * 1:0 MD1-MD0: Mode Select Bits
 *             MS1 | MS0 |   MODE
 *            ------------------------------
 *              0  |  0   |  Continuous-Conversion Mode.
 *              0  |  1   |  Single-Conversion Mode
 *              1  |  0   |  Negative Bias
 *              1  |  1   |  Sleep Mode
 */
static uint8_t CTRLB = 0x00;
static int32_t PIOS_HMC5883_Config(const struct pios_hmc5883_cfg * cfg)
{
	uint8_t CTRLA = 0x00;
	uint8_t MODE = 0x00;
	CTRLB = 0;
	
	CTRLA |= (uint8_t) (cfg->M_ODR | cfg->Meas_Conf);
	CTRLB |= (uint8_t) (cfg->Gain);
	MODE |= (uint8_t) (cfg->Mode);
	
	// CRTL_REGA
	if (PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_A, CTRLA) != 0)
		return -1;
	
	// CRTL_REGB
	if (PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_B, CTRLB) != 0)
		return -1;
	
	// Mode register
	if (PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, MODE) != 0) 
		return -1;
	
	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
 * \return 0 for success or -1 for failure
 */
int32_t PIOS_HMC5883_ReadMag(int16_t out[3])
{
	pios_hmc5883_data_ready = false;
	uint8_t buffer[6];
	int32_t temp;
	int32_t sensitivity;
	
	if (PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_XMSB_REG, buffer, 6) != 0) {
		return -1;
	}
		
	switch (CTRLB & 0xE0) {
		case 0x00:
			sensitivity =  PIOS_HMC5883_Sensitivity_0_88Ga;
			break;
		case 0x20:
			sensitivity = PIOS_HMC5883_Sensitivity_1_3Ga;
			break;
		case 0x40:
			sensitivity = PIOS_HMC5883_Sensitivity_1_9Ga;
			break;
		case 0x60:
			sensitivity = PIOS_HMC5883_Sensitivity_2_5Ga;
			break;
		case 0x80:
			sensitivity = PIOS_HMC5883_Sensitivity_4_0Ga;
			break;
		case 0xA0:
			sensitivity = PIOS_HMC5883_Sensitivity_4_7Ga;
			break;
		case 0xC0:
			sensitivity = PIOS_HMC5883_Sensitivity_5_6Ga;
			break;
		case 0xE0:
			sensitivity = PIOS_HMC5883_Sensitivity_8_1Ga;
			break;
		default:
			PIOS_Assert(0);
	}
	
	for (int i = 0; i < 3; i++) {
		temp = ((int16_t) ((uint16_t) buffer[2 * i] << 8)
				+ buffer[2 * i + 1]) * 1000 / sensitivity;
		out[i] = temp;
	}
	// Data reads out as X,Z,Y
	temp = out[2];
	out[2] = out[1];
	out[1] = temp;
	
	// This should not be necessary but for some reason it is coming out of continuous conversion mode
	PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, PIOS_HMC5883_MODE_CONTINUOUS);
	
	return 0;
}


/**
 * @brief Read the identification bytes from the HMC5883 sensor
 * \param[out] uint8_t array of size 4 to store HMC5883 ID.
 * \return 0 if successful, -1 if not
 */
uint8_t PIOS_HMC5883_ReadID(uint8_t out[4])
{
	uint8_t retval = PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_IDA_REG, out, 3);
	out[3] = '\0';
	return retval;
}

/**
 * @brief Tells whether new magnetometer readings are available
 * \return true if new data is available
 * \return false if new data is not available
 */
bool PIOS_HMC5883_NewDataAvailable(void)
{
	return (pios_hmc5883_data_ready);
}

/**
 * @brief Reads one or more bytes into a buffer
 * \param[in] address HMC5883 register address (depends on size)
 * \param[out] buffer destination buffer
 * \param[in] len number of bytes which should be read
 * \return 0 if operation was successful
 * \return -1 if error during I2C transfer
 * \return -2 if unable to claim i2c device
 */
static int32_t PIOS_HMC5883_Read(uint8_t address, uint8_t * buffer, uint8_t len)
{
	uint8_t addr_buffer[] = {
		address,
	};
	
	const struct pios_i2c_txn txn_list[] = {
		{
			.info = __func__,
			.addr = PIOS_HMC5883_I2C_ADDR,
			.rw = PIOS_I2C_TXN_WRITE,
			.len = sizeof(addr_buffer),
			.buf = addr_buffer,
		}
		,
		{
			.info = __func__,
			.addr = PIOS_HMC5883_I2C_ADDR,
			.rw = PIOS_I2C_TXN_READ,
			.len = len,
			.buf = buffer,
		}
	};
	
	return PIOS_I2C_Transfer(PIOS_I2C_MAIN_ADAPTER, txn_list, NELEMENTS(txn_list));
}

/**
 * @brief Writes one or more bytes to the HMC5883
 * \param[in] address Register address
 * \param[in] buffer source buffer
 * \return 0 if operation was successful
 * \return -1 if error during I2C transfer
 * \return -2 if unable to claim i2c device
 */
static int32_t PIOS_HMC5883_Write(uint8_t address, uint8_t buffer)
{
	uint8_t data[] = {
		address,
		buffer,
	};
	
	const struct pios_i2c_txn txn_list[] = {
		{
			.info = __func__,
			.addr = PIOS_HMC5883_I2C_ADDR,
			.rw = PIOS_I2C_TXN_WRITE,
			.len = sizeof(data),
			.buf = data,
		}
		,
	};
	;
	return PIOS_I2C_Transfer(PIOS_I2C_MAIN_ADAPTER, txn_list, NELEMENTS(txn_list));
}

/**
 * @brief Run self-test operation.  Do not call this during operational use!!
 * \return 0 if success, -1 if test failed
 */
int32_t PIOS_HMC5883_Test(void)
{
	int32_t failed = 0;
	uint8_t registers[3] = {0,0,0};
	uint8_t status;
	uint8_t ctrl_a_read;
	uint8_t ctrl_b_read;	
	uint8_t mode_read;
	int16_t values[3];
	
	
	
	/* Verify that ID matches (HMC5883 ID is null-terminated ASCII string "H43") */
	char id[4];
	PIOS_HMC5883_ReadID((uint8_t *)id);
	if((id[0] != 'H') || (id[1] != '4') || (id[2] != '3')) // Expect H43
		return -1;
	
	/* Backup existing configuration */
	if (PIOS_HMC5883_Read(PIOS_HMC5883_CONFIG_REG_A,registers,3) != 0)
		return -1;
	
	/* Stop the device and read out last value */
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, PIOS_HMC5883_MODE_IDLE) != 0) 
		return -1;
	if( PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_STATUS_REG, &status,1) != 0)
		return -1;
	if (PIOS_HMC5883_ReadMag(values) != 0)
		return -1;
	
	/*
	 * Put HMC5883 into self test mode
	 * This is done by placing measurement config into positive (0x01) or negative (0x10) bias
	 * and then placing the mode register into single-measurement mode.  This causes the HMC5883
	 * to create an artificial magnetic field of ~1.1 Gauss.
	 *
	 * If gain were PIOS_HMC5883_GAIN_2_5, for example, X and Y will read around +766 LSB
	 * (1.16 Ga * 660 LSB/Ga) and Z would read around +713 LSB (1.08 Ga * 660 LSB/Ga)
	 *
	 * Changing measurement config back to PIOS_HMC5883_MEASCONF_NORMAL will leave self-test mode.
	 */
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_A, PIOS_HMC5883_MEASCONF_BIAS_POS | PIOS_HMC5883_ODR_15) != 0)
		return -1;
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_B, PIOS_HMC5883_GAIN_8_1) != 0) 
		return -1;
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, PIOS_HMC5883_MODE_SINGLE) != 0) 
		return -1;
	
	/* Must wait for value to be updated */
	PIOS_DELAY_WaitmS(200);
	
	if (PIOS_HMC5883_ReadMag(values) != 0)
		return -1;
	
	/*
	 if(abs(values[0] - 766) > 20)
	 failed |= 1;
	 if(abs(values[1] - 766) > 20)
	 failed |= 1;
	 if(abs(values[2] - 713) > 20)
	 failed |= 1;
	*/
	
	PIOS_HMC5883_Read(PIOS_HMC5883_CONFIG_REG_A, &ctrl_a_read,1);
	PIOS_HMC5883_Read(PIOS_HMC5883_CONFIG_REG_B, &ctrl_b_read,1);
	PIOS_HMC5883_Read(PIOS_HMC5883_MODE_REG, &mode_read,1);
	PIOS_HMC5883_Read(PIOS_HMC5883_DATAOUT_STATUS_REG, &status,1);
	
	
	/* Restore backup configuration */
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_A, registers[0]) != 0)
		return -1;
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_CONFIG_REG_B, registers[1]) != 0) 
		return -1;
	PIOS_DELAY_WaitmS(10);
	if (PIOS_HMC5883_Write(PIOS_HMC5883_MODE_REG, registers[2]) != 0) 
		return -1;
	
	return failed;
}

/**
 * @brief IRQ Handler
 */
void PIOS_HMC5883_IRQHandler(void)
{
	pios_hmc5883_data_ready = true;
}

#endif /* PIOS_INCLUDE_HMC5883 */

/**
 * @}
 * @}
 */