/*
    TSL2561 for ChibiOS/RT - Copyright (C) 2016 Stephane D'Alu
*/

/**
 * @file    tsl2561.h
 * @brief   TSL2561 Light sensor interface module header.
 *
 * @{
 */

#ifndef _SENSOR_TSL2561_H_
#define _SENSOR_TSL2561_H_

#include <math.h>
#include "i2c_helpers.h"
#include "sensor.h"


/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

#define TSL2561_CONTINUOUS_ACQUISITION_SUPPORTED   TRUE

#define TSL2561_OVERLOADED        (-1)


/* I2C address */
#define TSL2561_I2CADDR_LOW          (0x29)
#define TSL2561_I2CADDR_FLOAT        (0x39)
#define TSL2561_I2CADDR_HIGH         (0x49)

/**
 * @brief Time necessary for the sensor to boot
 */
#define TSL2561_BOOTUP_TIME		0

/**
 * @brief Time necessary for the sensor to start
 */
#define TSL2561_STARTUP_TIME		0



/*===========================================================================*/
/* Driver pre-compile time settings.                                         */
/*===========================================================================*/

#ifndef TSL2561_WITH_CS
#define TSL2561_WITH_CS		  0
#endif

#ifndef TSL2561_WITH_T_FN_CL
#define TSL2561_WITH_T_FN_CL	  1
#endif


/*===========================================================================*/
/* Derived constants and error checks.                                       */
/*===========================================================================*/


#define TSL2561_I2CADDR_DEFAULT        TSL2561_I2CADDR_FLOAT


/*===========================================================================*/
/* Driver data structures and types.                                         */
/*===========================================================================*/

/**
 * @brief   TSL2561 configuration structure.
 */
typedef struct {
    I2CHelper i2c; /* keep it first */
} TSL2561_config;


typedef enum {
    TSL2561_INTEGRATIONTIME_SHORT      = 0x00,    // 13.7ms
    TSL2561_INTEGRATIONTIME_MEDIUM     = 0x01,    // 101ms
    TSL2561_INTEGRATIONTIME_LONG       = 0x02,    // 402ms
} TSL2561_integration_time_t;

typedef enum {
    TSL2561_GAIN_1X                    = 0x00,    // No gain
    TSL2561_GAIN_16X                   = 0x10,    // 16x gain
} TSL2561_gain_t;

/**
 * @brief   TSL2561 configuration structure.
 */
typedef struct {
    TSL2561_config  *config;
    sensor_state_t   state;
    unsigned int     delay;    
    uint16_t         cfg;
    TSL2561_gain_t   gain;
    TSL2561_integration_time_t integration_time;
    struct PACKED {
	uint8_t revno  : 4;
	uint8_t partno : 4; }  id;
} TSL2561_drv;

/*===========================================================================*/
/* Driver macros.                                                            */
/*===========================================================================*/


/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

/**
 * @brief Initialize the sensor driver
 */
void
TSL2561_init(TSL2561_drv *drv,
	TSL2561_config *config);

/**
 * @brief Start the sensor
 */
msg_t
TSL2561_start(TSL2561_drv *drv);

/**
 * @brief   Stop the sensor
 *
 * @details If the sensor support it, it will be put in low energy mode.
 */
msg_t
TSL2561_stop(TSL2561_drv *drv);

/**
 * @brief   Check that the sensor is really present
 */
msg_t
TSL2561_check(TSL2561_drv *drv);

/**
 * @brief Time in milli-seconds necessary for acquiring a naw measure
 *
 * @returns
 *   unsigned int   time in millis-seconds
 */
unsigned int
TSL2561_getAcquisitionTime(TSL2561_drv *drv);

/**
 * @brief Trigger a mesure acquisition
 */
static inline msg_t
TSL2561_startMeasure(TSL2561_drv *drv) {
    (void)drv;
    return MSG_OK;
};

/**
 * @brief Read the newly acquiered measure
 *
 * @note  According the the sensor design the measure read
 *        can be any value acquired after the acquisition time
 *        and the call to readMeasure.
 */
msg_t
TSL2561_readMeasure(TSL2561_drv *drv,
	unsigned int illuminance);

msg_t
TSL2561_setGain(TSL2561_drv *drv,
	TSL2561_gain_t gain);

msg_t
TSL2561_setIntegrationTime(TSL2561_drv *drv,
	TSL2561_integration_time_t time);

/**
 * @brief   Read temperature and humidity
 *
 * @details According to the sensor specification/configuration
 *          (see #TSL2561_CONTINUOUS_ACQUISITION_SUPPORTED), 
 *          if the sensor is doing continuous measurement
 *          it's value will be requested and returned immediately.
 *          Otherwise a measure is started, the necessary amount of
 *          time for acquiring the value is spend sleeping (not spinning),
 *          and finally the measure is read.
 *
 * @note    In continuous measurement mode, if you just started
 *          the sensor, you will need to wait getAcquisitionTime()
 *          in addition to the usual getStartupTime()

 * @note    If using several sensors, it is better to start all the
 *          measure together, wait for the sensor having the longuest
 *          aquisition time, and finally read all the values
 */
msg_t
TSL2561_readIlluminance(TSL2561_drv *drv,
	unsigned int *illuminance);

/**
 * @brief   Return the illuminance value in Lux
 *
 * @details Use readIlluminance() for returning the humidity value.
 *
 * @note    Prefere readIlluminance()if you need better error handling.
 *
 * @return Illuminance in Lux
 * @retval  unsigned int illuminace value 
 * @retval  -1           on failure
 */
static inline unsigned int
TSL2561_getIlluminance(TSL2561_drv *drv) {
    unsigned int illuminance = -1;
    TSL2561_readIlluminance(drv, &illuminance);
    return illuminance;
}


#endif