/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See the file COPYING
 *
 * 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.
 *
 * Copyright (C) 2010 Frank van Maarseveen <frankvm@frankvm.com>
 */

#ifndef _HARDWARE_H_
#define _HARDWARE_H_

#include <avr/io.h>
#include "bits.h"

/*
 * attiny85 lfuse:	0x62 -> 0x42	make lfuse
 *  7	CKDIV8:		0    0		init CLKPR[CLKPS] to 0011 (divide clock by 8)
 *  6	CKOUT		1    1
 *  5	SUT1:		1 -> 0		SUT=00: startup/reset asap (6+14CK)
 *  4	SUT0:		0    0
 *  3	CKSEL3		0    0
 *  2	CKSEL2		0    0
 *  1	CKSEL1		1    1
 *  0	CKSEL0		0    0
 *
 * attiny85 hfuse	0xdf -> 0xde	make hfuse
 *  7	RSTDISBL	1    1		note: programming this 0 affects SUT
 *  6	DWEN		1    1
 *  5	SPIEN		0    0
 *  4	WDTON		1    1
 *  3	EESAVE		1    1
 *  2	BODLEVEL2	1    1
 *  1	BODLEVEL1	1    1
 *  0	BODLEVEL0	1 -> 0		BOD at 1.8V
 *
 * attiny85 efuse	0xff -> 0xfe	make efuse
 *  0	SELFPRGGEN	1 -> 0		Enable self-programming
 *
 */

#define MHZ 4		/* CLKPR[CLKPS] will be set to 0001, dividing by 2 */

#define PWM1_MAX 160

/*
 * The signal LED is at pin 5, PB0. it is also used as input sensor for
 * optical reprogramming.
 */
#define LED		(B, 0)
//#define EEPROM_WRITE_LED LED

/*
 * The FET is at pin 6, PB1 (OC1A)
 */
#define FET		(B, 1)

/*
 * Mandatory hardware initialization: CPU clock and anything schematics
 * related which is critical. Interrupts should still be off.
 */
__attribute__((always_inline))
static inline void hw_init(void)
{
	CLKPR = _BV(CLKPCE);
	CLKPR = BIN8(0001);		/* CLKPS = 0001, divide final system clock by 2 */
	PORTB = 0;
	DDRB = 0;
	OUTPUT(FET);			/* switch FET off ASAP */
	DIDR0 = ~_BV(AIN0D);		/* exclude LED */
}

/*
 * ADC configuration and formulas to calculate ADC results from real values (constants)
 */
#define ILED(a) ((uint16_t)((a) * 0.04 * 20 * 1024 / 1.1 + 0.5))
#define ILED_MIN ILED(0.03)			/* 22 */
#define ILED_MAX ILED(1.0)			/* 745, max continuous current */
#define ILED_ADMUX (BIN8(0111) | _BV(REFS1))	/* ADC2(+), ADC3(-), gain=20, 1.1Vref */

#define VBAT(v) ((uint16_t)((v) * 10.0 / (10.0 + 22.0) * 1024 / 1.1 + 0.5))
#define VBAT_MIN VBAT(2.0)			/* 582, 1.0V per cell (avoid BORF upon switch-off) */
#define VBAT_REED_THRESHOLD VBAT(1.0)		/* 291 */
#define VBAT_ADMUX (BIN8(0001) | _BV(REFS1))	/* ADC1, 1.1Vref */

#define TEMP(c) ((uint16_t)((c) * 1.167 + 271))	/* very rough approximation, see manual */
#define TEMP_ADMUX (BIN8(1111) | _BV(REFS1))	/* ADC4, 1.1Vref */

/*
 * Eeprom logging
 */
#define EE_SLOT_BASE	(0x0002 >> 1)
#define EE_PWM1_MAX	(0 + EE_SLOT_BASE)
#define EE_ILED_MIN	(1 + EE_SLOT_BASE)
#define EE_ILED_MAX	(2 + EE_SLOT_BASE)
#define EE_ILED_MINTIME	(3 + EE_SLOT_BASE)
#define EE_ILED_MAXTIME	(4 + EE_SLOT_BASE)
#define EE_ILED_MINERR	(5 + EE_SLOT_BASE)
#define EE_ILED_MAXERR	(6 + EE_SLOT_BASE)
#define EE_ILED_MAXADJ	(7 + EE_SLOT_BASE)
#define EE_VBAT_MAX	(8 + EE_SLOT_BASE)
#define EE_TEMP_MIN	(9 + EE_SLOT_BASE)
#define EE_TEMP_MAX	(10 + EE_SLOT_BASE)
#define EE_ON_MAX	(11 + EE_SLOT_BASE)
//	,,		(12 + EE_SLOT_BASE)
#define EE_SLOT_END	(13 + EE_SLOT_BASE)

/*
 * Dive torch maintained state: on, off, or to implement a reset before calling
 * the bootloader.
 */
#define EEAR_RUNLEVEL	(0 + (EE_SLOT_END << 1))

/*
 * The boot-loader needs to maintain state to avoid executing random code
 * possibly damaging external hardware. Note: do not put anything else in
 * the same EEPROM page to avoid a bug destroying reprogram capability.
 */
#define EEAR_FLASH_STATE E2END

#endif