/***************************************************************************
 *   Copyright (C) 09/2007 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   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; version 2 of the License,               *
 *                                                                         *
 *   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.             *
 ***************************************************************************/
/*
 * Status			LED_GN	LED_RT
 * No Error, Motor off		ON	-
 * No Error, Motor spinup	FAST	-
 * No Error, Motor running	SLOW	-
 * Current Limit		F/S	ON
 * i2c Timeout			ON	ON
 * Undervoltage			OFF	SLOW
 * Overcurrent (Hard Limit)	OFF	FAST
 * SELFTEST failed		FAST	FAST	(not implemented yet)
 * EEPROM invalid		SLOW	SLOW
 */

#include <avr/io.h>
#include <avr/interrupt.h>

#include "main.h"
#include "blmc.h"
#include "eeprom.h"

#define LED_OFF		0x00
#define LED_SLOW	0x01
#define LED_FAST	0x10
#define LED_ON		0x11

extern struct blmc_ blmc;

static uint8_t led[2];

ISR(TIMER1_OVF_vect)
{
	static uint8_t rpm_cnt = 0;
	static uint8_t adc_chan = SENSE_CURRENT;

	/* Come back in 20ms */
	TCNT1 = (0xFFFF - 20000);

	/* commutations during last 20ms */
	uint16_t diff = blmc.rpm_tmp - blmc.rpm_tmp_old;
	blmc.rpm_tmp_old = blmc.rpm_tmp;

	if ((blmc.flags & FLAG_RUN_MASK) == (FLAG_PWM_NORMAL | FLAG_COM_NORMAL)) {
		/* too few commutations while running -> do a spinup */
		if (diff < 0x08) {
			blmc.flags &= ~(FLAG_RUN_MASK);
			blmc.flags |= FLAG_PWM_SPINUP | FLAG_COM_SPINUP;
		}

		/* no i2c cmd in the last 20ms */
		if (!(blmc.flags & FLAG_I2C_ACTIVE)) {
			/* already in i2c timeout, turn off motor */
			if (blmc.flags & FLAG_I2C_TIMEOUT)
				blmc.pwm = 0;

			blmc.flags |= FLAG_I2C_TIMEOUT;

		} else {
			blmc.flags &= ~FLAG_I2C_TIMEOUT;
		}

// TODO: currently disabled
// 		blmc.flags &= ~FLAG_I2C_ACTIVE;
	}

	/* set pwm again (adjust current limit) */
	setpwm(blmc.pwm);

	/* calc rpm every second */
	rpm_cnt++;
	if (rpm_cnt == 50) {
		rpm_cnt = 0;

		blmc.rpm = blmc.rpm_tmp;
		blmc.rpm_tmp = 0;
	}

	/* trigger adc by hand when not running */
	if (!(blmc.flags & FLAG_COM_NORMAL)) {
		trigger_adc(adc_chan);
		if (adc_chan == SENSE_CURRENT)
			adc_chan = SENSE_VOLTAGE;
		else
			adc_chan = SENSE_CURRENT;
	}

	/* led blink timer */
	static uint8_t led_timer = 0;
	led_timer = (led_timer +1) & 0x1F;

	/* green LED */
	if (((led[0] == LED_SLOW) && (led_timer & 0x10)) ||
	     (led[0] == LED_FAST && (led_timer & 0x04)) ||
	     (led[0] == LED_ON)) {
		PORTB |= LED_GN;

	} else {
		PORTB &= ~LED_GN;
	}

	/* red LED */
	if (((led[1] == LED_SLOW) && !(led_timer & 0x10)) ||
	     (led[1] == LED_FAST && !(led_timer & 0x04)) ||
	     (led[1] == LED_ON)) {
		PORTB |= LED_RT;

	} else {
		PORTB &= ~LED_RT;
	}
}

/*
 * For newer devices (mega88) the watchdog timer remains active even after a
 * system reset. So disable it as soon as possible.
 * automagically called on startup
 */
void get_mcusr(void) __attribute__((naked, section(".init3")));
void get_mcusr(void)
{
	MCUSR = 0;
	WDTCSR = (1<<WDCE) | (0<<WDE);
}

int main(void)
{
	DDRB = PHASE_A_EN | PHASE_A_PWM | LED_RT | LED_GN;
	DDRD = PHASE_B_EN | PHASE_B_PWM | PHASE_C_EN | PHASE_C_PWM;

	PORTB = 0x00;
	PORTD = 0x00;

	/* timer0: running with F_CPU, 8bit Phase Correct PWM (16kHz) */
	TCCR0A = (1<<WGM00);
	TCCR0B = (1<<CS00);

	/* timer1: running with F_CPU/8 */
	TCCR1B = (1<<CS11);

	/* timer2: running with F_CPU, 8bit Phase Correct PWM (16kHz) */
	TCCR2A = (1<<WGM20);
	TCCR2B = (1<<CS20);

	/* enable Timer1 OVF Interrupt */
	TIMSK1 = (1<<TOIE1);

	/* Enable Analog Comparator Multiplexer */
	ADCSRB |= (1<<ACME);

	/* I2C Init: keep Address from bootloader, Auto ACKs with Interrupts */
	TWCR = (1<<TWEA) | (1<<TWEN) | (1<<TWIE);

	blmc.flags = 0x00;
	if (read_parameters())
		blmc.flags |= FLAG_INVALID_EEPROM;

	sei();

	while (1) {
		uint8_t ledX[2] = { 0x00, 0x00 };

		/* get motor status: spinup, running or off */
		if (blmc.flags & FLAG_RUN_MASK) {
			if (blmc.flags & (FLAG_COM_SPINUP | FLAG_PWM_SPINUP))
				ledX[0] = LED_FAST;
			else
				ledX[0] = LED_SLOW;
		} else {
			ledX[0] = LED_ON;
		}

		/* soft errors (current limit, i2c timeout) */
		if (blmc.flags & FLAG_SOFTERR_MASK)
			ledX[1] = LED_ON;

		/* hard errors */
		if (blmc.flags & FLAG_HARDERR_MASK) {
			if (blmc.flags & FLAG_CURRENT_LIMIT) {
				ledX[0] = LED_OFF;
				ledX[1] = LED_FAST;

			} else if (blmc.flags & FLAG_UNDERVOLTAGE) {
				ledX[0] = LED_OFF;
				ledX[1] = LED_SLOW;

			} else if (blmc.flags & FLAG_SELFTEST_FAILED) {
				ledX[0] = LED_FAST;
				ledX[1] = LED_FAST;

			} else if (blmc.flags & FLAG_INVALID_EEPROM) {
				ledX[0] = LED_SLOW;
				ledX[1] = LED_SLOW;
			}
		}

		if (!(blmc.flags & (FLAG_SOFTERR_MASK | FLAG_HARDERR_MASK)))
			ledX[1] = LED_OFF;

		led[0] = ledX[0];
		led[1] = ledX[1];

		/* do a spinup from main loop (blocking for > 200ms) */
		if (blmc.flags & FLAG_COM_SPINUP)
			spinup();
	};
	return 0;
}