/******************************************************************************
Copyright 2008, Freie Universitaet Berlin (FUB). All rights reserved.

These sources were developed at the Freie Universitaet Berlin, Computer Systems
and Telematics group (http://cst.mi.fu-berlin.de).
-------------------------------------------------------------------------------
This file is part of FeuerWare.

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.

FeuerWare 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, see http://www.gnu.org/licenses/ .
--------------------------------------------------------------------------------
For further information and questions please use the web site
	http://scatterweb.mi.fu-berlin.de
and the mailinglist (subscription via web site)
	scatterweb@lists.spline.inf.fu-berlin.de
*******************************************************************************/

/**
 * @ingroup		dev_cc110x
 * @{
 */

/**
 * @file
 * @internal
 * @brief		TI Chipcon CC110x Radio driver
 *
 * @author      Freie Universität Berlin, Computer Systems & Telematics, FeuerWhere project
 * @author		Thomas Hillebrandt <hillebra@inf.fu-berlin.de>
 * @author		Heiko Will <hwill@inf.fu-berlin.de>
 * @version     $Revision: 2283 $
 *
 * @note		$Id: cc1100.c 2283 2010-06-15 14:02:27Z hillebra $
 */

#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "irq.h"
#include "arch_cc1100.h"
#include "cc1100.h"
#include "cc1100_phy.h"
#include "cc1100_spi.h"
#include "cc1100-internal.h"
#include "cc1100-defaultSettings.h"

#include "hwtimer.h"
#include "core/include/bitarithm.h"

// TODO: cc1100 port timer
#ifdef FEUERWARE_CPU_LPC2387
//#include "cpu/lpc2387/lpc2387-timer2.h"
#endif

#if defined(FEUERWARE_CPU_MSP430)
#include <msp430x16x.h>
#elif defined(FEUERWARE_CPU_LPC2387)
#include "lpc2387.h"
#endif

#define PACKET_LENGTH				(0x3E)		///< Packet length = 62 Bytes.
#define CC1100_SYNC_WORD_TX_TIME   (90000)		// loop count (max. timeout ~ 15 ms) to wait for
												// sync word to be transmitted (GDO2 from low to high)

/**
 * @name	Virtual Radio Device methods (see vdevice_radio_methods)
 * @{
 */
static int rd_set_mode(int mode);
/** @} */

static void switch_to_wor(void);

/*---------------------------------------------------------------------------*/
//					Power control data structures
/*---------------------------------------------------------------------------*/

static uint8_t pa_table_index = PATABLE;	///< Current PATABLE Index
static uint8_t pa_table[] = {				///< PATABLE with available output powers
				   0x00,					///< -52 dBm
				   0x03,					///< -30 dBm
				   0x0D,					///< -20 dBm
				   0x1C,					///< -15 dBm
				   0x34,					///< -10 dBm
				   0x57,					///< - 5 dBm
				   0x3F,					///< - 1 dBm
				   0x8E,					///<   0 dBm
				   0x85,					///< + 5 dBm
				   0xCC,					///< + 7 dBm
				   0xC6, 					///< + 9 dBm
				   0xC3  					///< +10 dBm
}; // If PATABLE is changed in size, adjust MAX_OUTPUT_POWER definition in CC1100 interface!

static int8_t pa_table_dBm[] = {			///< Values of the PATABLE in dBm
				   -52,
				   -30,
				   -20,
				   -15,
				   -10,
				    -5,
				    -1,
				     0,
				     5,
				     7,
				     9,
				    10
};

/*---------------------------------------------------------------------------*/
//					Main radio data structures
/*---------------------------------------------------------------------------*/

volatile cc1100_flags rflags;		///< Radio control flags
static uint8_t radio_address;		///< Radio address
static uint8_t radio_channel;		///< Radio channel number

const radio_t radio_cc1100 = {		///< Radio driver API
	"CC1100",
	CC1100_BROADCAST_ADDRESS,
	MAX_OUTPUT_POWER,
	cc1100_get_avg_transmission_duration,
	cc1100_get_address,
	cc1100_set_address,
	cc1100_set_output_power,
	cc1100_set_packet_monitor,
	cc1100_set_packet_handler,
	cc1100_send_csmaca,
	cc1100_print_statistic,
	cc1100_print_config
};

/*---------------------------------------------------------------------------*/
//					 Data structures for mode control
/*---------------------------------------------------------------------------*/

volatile uint8_t radio_mode;						///< Radio mode
volatile uint8_t radio_state = RADIO_UNKNOWN;		///< Radio state

volatile cc1100_mode_callback_t cc1100_go_idle;		///< Function for going IDLE
volatile cc1100_mode_callback_t cc1100_go_receive;	///< Function for going RX
volatile cc1100_mode_callback_t cc1100_go_after_tx;	///< Function to call after TX (burst send)
volatile cc1100_mode_callback_t cc1100_setup_mode;	///< Function to set up selected mode (RX or WOR)

volatile int wor_hwtimer_id = -1;

/*---------------------------------------------------------------------------*/
// 						Low-level hardware access
/*---------------------------------------------------------------------------*/

void cc1100_disable_interrupts(void)
{
	cc1100_gdo2_disable();
	cc1100_gdo0_disable();
}

void cc1100_gdo0_irq(void)
{
	// Air was not free -> Clear CCA flag
	rflags.CAA = false;
	// Disable carrier sense detection (GDO0 interrupt)
	cc1100_gdo0_disable();
}

void cc1100_gdo2_irq(void)
{
	cc1100_phy_rx_handler();
}

/*---------------------------------------------------------------------------*/
// 		High level CC1100 SPI functions for transferring packet out
//		of RX FIFO (don't call when in WOR mode)
/*---------------------------------------------------------------------------*/

static bool spi_receive_packet_variable(uint8_t *rxBuffer, uint8_t length)
{
	// Needed here for statistics
	extern cc1100_statistic_t cc1100_statistic;

	uint8_t status[2];
	uint8_t packetLength = 0;

	// Any bytes available in RX FIFO?
	if ((cc1100_spi_read_status(CC1100_RXBYTES) & BYTES_IN_RXFIFO))
	{
		// Read length byte (first byte in RX FIFO)
        packetLength = cc1100_spi_read_reg(CC1100_RXFIFO);
		// Read data from RX FIFO and store in rxBuffer
        if (packetLength <= length)
		{
			// Put length byte at first position in RX Buffer
			rxBuffer[0] = packetLength;

			// Read the rest of the packet
			cc1100_spi_readburst_reg(CC1100_RXFIFO, (char*)rxBuffer+1, packetLength);

            // Read the 2 appended status bytes (status[0] = RSSI, status[1] = LQI)
			cc1100_spi_readburst_reg(CC1100_RXFIFO, (char*)status, 2);

			// Store RSSI value of packet
			rflags.RSSI = status[I_RSSI];

			// MSB of LQI is the CRC_OK bit
			rflags.CRC = (status[I_LQI] & CRC_OK) >> 7;
			if (!rflags.CRC) cc1100_statistic.packets_in_crc_fail++;

			// Bit 0-6 of LQI indicates the link quality (LQI)
			rflags.LQI = status[I_LQI] & LQI_EST;

			return rflags.CRC;
        }
		else
		{
			// RX FIFO get automatically flushed if return value is false
            return false;
        }
	}
	else
	{
		// RX FIFO get automatically flushed if return value is false
		return false;
	}
}

bool cc1100_spi_receive_packet(uint8_t *rxBuffer, uint8_t length)
{
	uint8_t pkt_len_cfg = cc1100_spi_read_reg(CC1100_PKTCTRL0) & PKT_LENGTH_CONFIG;
	if (pkt_len_cfg == VARIABLE_PKTLEN)
	{
		return spi_receive_packet_variable(rxBuffer, length);
	}
	// Fixed packet length not supported.
	// RX FIFO get automatically flushed if return value is false
	return false;
}

/*---------------------------------------------------------------------------*/
// 							CC1100 mode functionality
/*---------------------------------------------------------------------------*/

void cc1100_set_idle(void) {
	if (radio_state == RADIO_WOR) {
		// Wake up the chip from WOR/sleep
		cc1100_spi_select();
		hwtimer_wait(RTIMER_TICKS(122));
		cc1100_spi_unselect();
		radio_state = RADIO_IDLE;
		// XOSC startup + FS calibration (300 + 809 us  ~ 1.38 ms)
		hwtimer_wait(FS_CAL_TIME);
		return;
	}
	cc1100_spi_strobe(CC1100_SIDLE);
	radio_state = RADIO_IDLE;
}

static void wakeup_from_rx(void)
{
	if (radio_state != RADIO_RX) return;
	cc1100_spi_strobe(CC1100_SIDLE);
	radio_state = RADIO_IDLE;
}

static void switch_to_rx(void)
{
	radio_state = RADIO_RX;
	cc1100_spi_strobe(CC1100_SRX);
}

static void setup_rx_mode(void)
{
	// Stay in RX mode until end of packet
	cc1100_spi_write_reg(CC1100_MCSM2, 0x07);
	switch_to_rx();
}

/**
 * Note: It is possible that this code is executed in an ISR!
 */
static void wakeup_from_wor(void)
{
	if (radio_state != RADIO_WOR) {
		return;
	}
	// Wake up the chip from WOR/sleep
	cc1100_spi_select();
	hwtimer_wait(RTIMER_TICKS(122));
	cc1100_spi_unselect();
	radio_state = RADIO_IDLE;
	// XOSC startup + FS calibration (300 + 809 us  ~ 1.38 ms)
	hwtimer_wait(FS_CAL_TIME);
}

/**
 * Note: This code is executed in the hwtimer ISR!
 */
void switch_to_wor2(void)
{
	if (cc1100_get_gdo2()) return;				// If incoming packet, then don't go to WOR now
	cc1100_spi_strobe(CC1100_SIDLE);			// Put CC1100 to IDLE
	radio_state = RADIO_IDLE;					// Radio state now IDLE
	cc1100_spi_write_reg(CC1100_MCSM2,
			cc1100_wor_config.rx_time_reg);		// Configure RX_TIME (for use in WOR)
	cc1100_spi_write_reg(CC1100_MCSM0, 0x18);	// Turn on FS-Autocal
	if (rflags.WOR_RST) {
		cc1100_spi_strobe(CC1100_SWORRST);		// Resets the real time clock
		rflags.WOR_RST = false;
	}
	cc1100_spi_strobe(CC1100_SWOR);				// Put radio back to sleep/WOR (must be in IDLE when this is done)
	radio_state = RADIO_WOR;					// Radio state now WOR
}

/**
 * Note: This code is executed in the hwtimer ISR!
 */
static void hwtimer_switch_to_wor2_wrapper(void* ptr)
{
	wor_hwtimer_id = -1;							// kernel timer handler function called, clear timer id
	if (rflags.TX) return;						// Stability: don't allow WOR timers at this point
	rflags.WOR_RST = true;
	switch_to_wor2();
}

/**
 * Note: This code is executed in the hwtimer ISR!
 */
static void switch_to_wor(void)
{
	// Any incoming packet?
	if (cc1100_get_gdo2())
	{
		// Then don't go to WOR now
		return;
	}

	// Step 1: Set chip for random interval (1..RX_INTERVAL) to power down mode
	if (!rflags.MAN_WOR)
	{
		rflags.MAN_WOR = true;
		radio_state = RADIO_WOR;
		// Go to power down mode
		cc1100_spi_strobe(CC1100_SIDLE);
		cc1100_spi_strobe(CC1100_SPWD);

		// Set timer to do second step of manual WOR
		int r = (rand() / (double)(RAND_MAX + 1.0)) * (cc1100_wor_config.rx_interval * 100.0) + 20;
		wor_hwtimer_id = hwtimer_set(r, cc1100_hwtimer_go_receive_wrapper, NULL);
		if (wor_hwtimer_id == -1)
		{
			rflags.KT_RES_ERR = true;
			// No hwtimer available, go immediately to WOR mode.
			// Else never receiving packets again...
			rflags.MAN_WOR = false;
			switch_to_wor2();
		}
	}
	// Step 2: Go to RX and then to WOR mode again
	else
	{
		rflags.MAN_WOR = false;
		wakeup_from_wor();
		cc1100_spi_strobe(CC1100_SRX);
		hwtimer_wait(IDLE_TO_RX_TIME);
		radio_state = RADIO_RX;
		// Register timer to go to WOR after RX timeout
		wor_hwtimer_id = hwtimer_set((cc1100_wor_config.rx_time_ms * 100 + 150),
				hwtimer_switch_to_wor2_wrapper, NULL); // add 1,5 ms secure time
		if (wor_hwtimer_id == -1)
		{
			rflags.KT_RES_ERR = true;
		}
	}
}

static void setup_wor_mode(void)
{
	// Wake up from WOR (if in WOR, else no effect)
	cc1100_go_idle();

	// Make sure CC1100 is in IDLE state
	cc1100_spi_strobe(CC1100_SIDLE);

	// Enable automatic initial calibration of RCosc.
	// Set T_event1 ~ 1.4 ms, enough for XOSC stabilize and FS calibration before RX.
    // Enable RC oscillator before starting with WOR (or else it will not wake up).
	// Not using AUTO_SYNC function.
	cc1100_spi_write_reg(CC1100_WORCTRL, cc1100_wor_config.wor_ctrl);

	// Set Event0 timeout (RX polling interval)
	cc1100_spi_write_reg(CC1100_WOREVT1, cc1100_wor_config.wor_evt_1);
	cc1100_spi_write_reg(CC1100_WOREVT0, cc1100_wor_config.wor_evt_0);

	// Set RX time in WOR mode
	cc1100_spi_write_reg(CC1100_MCSM2, cc1100_wor_config.rx_time_reg);

	// Enable automatic FS calibration when going from IDLE to RX/TX/FSTXON (in between EVENT0 and EVENT1)
	cc1100_spi_write_reg(CC1100_MCSM0, 0x18);

	// Put the radio to SLEEP by starting Wake-on-Radio.
	cc1100_spi_strobe(CC1100_SWORRST);	// Resets the real time clock
	cc1100_spi_strobe(CC1100_SWOR);		// Starts Wake-on-Radio
	radio_state = RADIO_WOR;
}

static void switch_to_pwd(void)
{
	cc1100_go_idle();
	cc1100_spi_strobe(CC1100_SPWD);
	radio_state = RADIO_PWD;
}

uint8_t cc1100_get_mode(void)
{
	return radio_mode;
}

static bool cc1100_set_mode0(uint8_t mode, uint16_t opt_mode_data)
{
	int result;
	switch (mode)
	{
		case CC1100_MODE_WOR:
			// Calculate WOR settings, store result (new burst count)
			result = cc1100_phy_calc_wor_settings(opt_mode_data);
			// If settings can be applied, set new mode and burst count
			if (result != -1)
			{
				radio_mode = mode;
				cc1100_go_idle = wakeup_from_wor;
				cc1100_go_receive = switch_to_wor;
				cc1100_go_after_tx = switch_to_wor2;
				cc1100_setup_mode = setup_wor_mode;
				cc1100_burst_count = result;
				cc1100_retransmission_count_uc = TRANSMISSION_RETRIES_WOR_UC;
				cc1100_retransmission_count_bc = TRANSMISSION_RETRIES_WOR_BC;
				return true;
			}
			break;
		case CC1100_MODE_CONSTANT_RX:
			radio_mode = mode;
			cc1100_go_idle = wakeup_from_rx;
			cc1100_go_receive = switch_to_rx;
			cc1100_go_after_tx = switch_to_rx;
			cc1100_setup_mode = setup_rx_mode;
			cc1100_burst_count = 1;
			cc1100_retransmission_count_uc = TRANSMISSION_RETRIES_CRX_UC;
			cc1100_retransmission_count_bc = TRANSMISSION_RETRIES_CRX_BC;
			return true;
	}
	return false;
}

bool cc1100_set_mode(uint8_t mode, uint16_t opt_mode_data)
{
	// Wake up from WOR/RX (if in WOR/RX, else no effect)
	cc1100_go_idle();

	// Make sure CC1100 is in IDLE state
	cc1100_spi_strobe(CC1100_SIDLE);

	// Set the new mode
	bool result = cc1100_set_mode0(mode, opt_mode_data);

	// If mode change was successful (mode is valid)
	if (result)
	{
		// Setup new mode configuration
		cc1100_setup_mode();
		// Reset statistics
		cc1100_reset_statistic();
		return true;
	}
	else
	{
		// Still in old mode, go to receive mode again
		cc1100_go_receive();
		return false;
	}
}

char* cc1100_mode_to_text(uint8_t mode)
{
	switch (mode)
	{
		case CC1100_MODE_WOR:
			return "Wake-On-Radio";
		case CC1100_MODE_CONSTANT_RX:
			return "Constant RX";
		default:
			return "unknown";
	}
}

char* cc1100_state_to_text(uint8_t state)
{
	switch (state)
	{
		case RADIO_UNKNOWN:
			return "Unknown";
		case RADIO_AIR_FREE_WAITING:
			return "CS";
		case RADIO_WOR:
			return "WOR";
		case RADIO_IDLE:
			return "IDLE";
		case RADIO_SEND_BURST:
			return "TX BURST";
		case RADIO_RX:
			return "RX";
		case RADIO_SEND_ACK:
			return "TX ACK";
		case RADIO_PWD:
			return "PWD";
		default:
			return "unknown";
	}
}

void cc1100_hwtimer_go_receive_wrapper(void *ptr)
{
	// kernel timer handler function called, clear timer id
	wor_hwtimer_id = -1;
	// Stability: don't allow WOR timers at this point
	if (rflags.TX) return;
	if (radio_state == RADIO_PWD) {
		// Go to RX state, listen for packets as long as WOR_TIMEOUT_2
		cc1100_spi_strobe(CC1100_SRX);
		hwtimer_wait(IDLE_TO_RX_TIME);
		radio_state = RADIO_RX;
		// Set hwtimer to put CC1100 back to WOR after WOR_TIMEOUT_2
		wor_hwtimer_id = hwtimer_set(WOR_TIMEOUT_2, cc1100_hwtimer_go_receive_wrapper, NULL);
		if (wor_hwtimer_id == -1)
		{
			rflags.KT_RES_ERR = true;
			// No hwtimer available, go immediately to WOR mode.
			// Else never receiving packets again...
			rflags.MAN_WOR = false;
			switch_to_wor2();
		}
	} else {
		cc1100_go_receive();
	}
}

/*---------------------------------------------------------------------------*/
// 							CC1100 reset functionality
/*---------------------------------------------------------------------------*/

static void reset(void)
{
	cc1100_go_idle();
	cc1100_spi_select();
	cc1100_spi_strobe(CC1100_SRES);
	hwtimer_wait(RTIMER_TICKS(10));
}

static void power_up_reset(void)
{
	cc1100_spi_unselect();
	cc1100_spi_cs();
	cc1100_spi_unselect();
	hwtimer_wait(RESET_WAIT_TIME);
	reset();
	radio_state = RADIO_IDLE;
}

/*---------------------------------------------------------------------------*/
// 							CC1100 low level send function
/*---------------------------------------------------------------------------*/

void cc1100_send_raw(uint8_t *tx_buffer, uint8_t size)
{
	volatile uint32_t abort_count;
	// The number of bytes to be transmitted must be smaller
	// or equal to PACKET_LENGTH (62 bytes). So the receiver
	// can put the whole packet in its RX-FIFO (with appended
	// packet status bytes).
	if (size > PACKET_LENGTH) return;

	// Disables RX interrupt etc.
	cc1100_before_send();

	// But CC1100 in IDLE mode to flush the FIFO
    cc1100_spi_strobe(CC1100_SIDLE);
    // Flush TX FIFO to be sure it is empty
    cc1100_spi_strobe(CC1100_SFTX);
	// Write packet into TX FIFO
    cc1100_spi_writeburst_reg(CC1100_TXFIFO, (char*) tx_buffer, size);
  	// Switch to TX mode
    abort_count = 0;
    unsigned int cpsr = disableIRQ();
    cc1100_spi_strobe(CC1100_STX);
    // Wait for GDO2 to be set -> sync word transmitted
    while (cc1100_get_gdo2() == 0) {
    	abort_count++;
    	if (abort_count > CC1100_SYNC_WORD_TX_TIME) {
    		// Abort waiting. CC1100 maybe in wrong mode
    		// e.g. sending preambles for always
    		puts("[CC1100 TX] fatal error\n");
    		break;
    	}
    }
    restoreIRQ(cpsr);
	// Wait for GDO2 to be cleared -> end of packet
    while (cc1100_get_gdo2() != 0);
    // Experimental - TOF Measurement
    cc1100_after_send();
}

/*---------------------------------------------------------------------------*/
// 		Various functions (mode safe - they can be called in any radio mode)
/*---------------------------------------------------------------------------*/
uint8_t
read_register(uint8_t r)
{
	uint8_t result;

	// Save old radio state
	uint8_t old_state = radio_state;

	// Wake up from WOR/RX (if in WOR/RX, else no effect)
	cc1100_go_idle();
	result = cc1100_spi_read_reg(r);
	// Have to put radio back to WOR/RX if old radio state
	// was WOR/RX, otherwise no action is necessary
	if (old_state == RADIO_WOR || old_state == RADIO_RX) {
		cc1100_go_receive();
	}

	return result;
}

static void
write_register(uint8_t r, uint8_t value)
{
	// Save old radio state
	uint8_t old_state = radio_state;

	// Wake up from WOR/RX (if in WOR/RX, else no effect)
	cc1100_go_idle();
	cc1100_spi_write_reg(r, value);

	// Have to put radio back to WOR/RX if old radio state
	// was WOR/RX, otherwise no action is necessary
	if (old_state == RADIO_WOR || old_state == RADIO_RX) {
		cc1100_go_receive();
	}
}

char* cc1100_get_output_power(char* buf)
{
	sprintf(buf, "%+i dBm", pa_table_dBm[pa_table_index]);
	return buf;
}

uint8_t cc1100_get_channel(void)
{
	return radio_channel;
}

bool
cc1100_set_channel(uint8_t channr)
{
	if (channr > MAX_CHANNR) return false;
	write_register(CC1100_CHANNR, channr*10);
	radio_channel = channr;
	return true;
}

bool
cc1100_set_output_power(uint8_t pa_idx)
{
	if (pa_idx >= sizeof(pa_table)) return false;
	write_register(CC1100_PATABLE, pa_table[pa_idx]);
	pa_table_index = pa_idx;
	return true;
}

char* cc1100_get_marc_state(void)
{
	uint8_t state;

	// Save old radio state
	uint8_t old_state = radio_state;

	// Read content of status register
	state = cc1100_spi_read_status(CC1100_MARCSTATE) & MARC_STATE;

	// Make sure in IDLE state.
	// Only goes to IDLE if state was RX/WOR
	cc1100_go_idle();

	// Have to put radio back to WOR/RX if old radio state
	// was WOR/RX, otherwise no action is necessary
	if (old_state == RADIO_WOR || old_state == RADIO_RX) {
		cc1100_go_receive();
	}

	switch (state)
	{
		// Note: it is not possible to read back the SLEEP or XOFF state numbers
		// because setting CSn low will make the chip enter the IDLE mode from the
		// SLEEP (0) or XOFF (2) states.
		case 1: return "IDLE";
		case 3: case 4: case 5: return "MANCAL";
		case 6: case 7: return "FS_WAKEUP";
		case 8: case 12: return "CALIBRATE";
		case 9: case 10: case 11: return "SETTLING";
		case 13: case 14: case 15: return "RX";
		case 16: return "TXRX_SETTLING";
		case 17: return "RXFIFO_OVERFLOW";
		case 18: return "FSTXON";
		case 19: case 20: return "TX";
		case 21: return "RXTX_SETTLING";
		case 22: return "TXFIFO_UNDERFLOW";
		default: return "UNKNOWN";
	}
}

/*
static int8_t
rssi_2_dbm(uint8_t rssi)
{
	if (rssi >= 128) rssi -= 256;
	rssi /= 2;
	rssi -= 78;
	return rssi;
}*/

/*---------------------------------------------------------------------------*/
// 								Radio Driver API
/*---------------------------------------------------------------------------*/
void cc1100_init(void)
{
    // Initialize SPI
	cc1100_spi_init();

    // Set default mode (with default (energy optimized) RX interval)
	cc1100_set_mode0(CC1100_RADIO_MODE, T_RX_INTERVAL);

	// Load driver & reset
	power_up_reset();

    // Write configuration to configuration registers
	extern char cc1100_conf[];
    cc1100_spi_writeburst_reg(0x00, cc1100_conf, CC1100_CONF_SIZE);

	// Write PATABLE (power settings)
	cc1100_spi_write_reg(CC1100_PATABLE, pa_table[pa_table_index]);

	// Initialize Radio Flags
	rflags.RSSI = 0x00;
	rflags.LL_ACK = false;
	rflags.CAA = false;
	rflags.CRC = false;
	rflags.SEQ = false;
	rflags.MAN_WOR = false;
	rflags.KT_RES_ERR = false;
	rflags.TX = false;
	rflags.WOR_RST = false;

	// Initialize physical layer
	cc1100_phy_init();

	// Set radio address of CC1100
	cc1100_set_address(radio_address);

	// Set default channel number
	radio_channel = CC1100_DEFAULT_CHANNR;

	// Switch to desired mode (WOR or RX)
	rd_set_mode(RADIO_MODE_ON);
}

int cc1100_get_avg_transmission_duration(void)
{
	if (radio_mode == CC1100_MODE_WOR) {
		// Transmission duration ~ RX interval
		// Double value because of MAC delay.
		return 2 * cc1100_wor_config.rx_interval;
	} else {
		// Transmission duration ~ 32 ms
		// Double value because of MAC delay.
		return 2 * 32;
	}
}

radio_address_t cc1100_get_address(void)
{
	return radio_address;
}

bool cc1100_set_address(radio_address_t address)
{
	if (address < MIN_UID || address > MAX_UID)
	{
		return false;
	}

	uint8_t id = (uint8_t) address;
	if (radio_state != RADIO_UNKNOWN)
	{
		write_register(CC1100_ADDR, id);
	}

	radio_address = id;
	return true;
}

static int
rd_set_mode(int mode)
{
	int result;

	// Get current radio mode
	if (radio_state == RADIO_UNKNOWN || radio_state == RADIO_PWD)
	{
		result = RADIO_MODE_OFF;
	}
	else
	{
		result = RADIO_MODE_ON;
	}

	switch (mode)
	{
		case RADIO_MODE_ON:
			cc1100_init_interrupts();			// Enable interrupts
			cc1100_setup_mode();				// Set chip to desired mode
			break;
		case RADIO_MODE_OFF:
			cc1100_disable_interrupts();		// Disable interrupts
			switch_to_pwd();					// Set chip to power down mode
			break;
		case RADIO_MODE_GET:
			// do nothing, just return current mode
		default:
			// do nothing
			break;
	}

	// Return previous mode
	return result;
}

/*---------------------------------------------------------------------------*/
// 						Carrier sense interface functions
/*---------------------------------------------------------------------------*/

void cc1100_cs_init(void)
{
	cc1100_go_idle();							// Wake CC1100 up from Wake-On-Radio mode
	if (radio_state == RADIO_RX)				// If radio in RX mode
	{
		cc1100_spi_strobe(CC1100_SIDLE);		// Go back to IDLE for calibration
	}
	cc1100_spi_write_reg(CC1100_MCSM0, 0x08);	// Turn off FS-Autocal
	cc1100_spi_strobe(CC1100_SCAL);				// Calibrate manually (721 us)
	hwtimer_wait(MANUAL_FS_CAL_TIME);			// Wait for calibration to finish before packet burst can start
	radio_state = RADIO_AIR_FREE_WAITING;		// Set status "waiting for air free"
	cc1100_spi_write_reg(CC1100_MCSM2, 0x07);	// Configure RX_TIME = Until end of packet (no timeout)
	cc1100_spi_strobe(CC1100_SRX);				// Switch to RX (88.4 us) (Carrier Sense)
	hwtimer_wait(CS_READY_TIME);					// Wait until CC1100 is in RX + carrier sense ready (GDO0 ready for readout -> data rate dependent!!!)
}

void cc1100_cs_set_enabled(bool enabled)
{
	if (enabled)
	{
		// Enable carrier sense detection (GDO0 interrupt)
		cc1100_gdo0_enable();
	}
	else
	{
		// Disable carrier sense detection (GDO0 interrupt)
		cc1100_gdo0_disable();
	}
}

int cc1100_cs_read(void)
{
	/* GDO0 reflects CS (high: air not free, low: air free) */
	return cc1100_get_gdo0();
}

int cc1100_cs_read_cca(void)
{
	return rflags.CAA;
}

void cc1100_cs_write_cca(const int cca)
{
	rflags.CAA = cca;
}
/*---------------------------------------------------------------------------*/
/** @} */