/*
 * Copyright (c) 2004
 *      Daniel O'Connor <darius@dons.net.au>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stdio.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>
#include <avr/pgmspace.h>
#include <string.h>
#include <ctype.h>

#include "1wire.h"

#define UART_BAUD_SELECT(baudRate,xtalCpu) ((xtalCpu)/((baudRate)*16l)-1)
#define XTAL_CPU         4000000      /* 4Mhz */
#define UART_BAUD_RATE      19200

void		uart_putsP(const char *addr);
void		uart_puts(const char *addr);
int		uart_putc(char c);
int		uart_getc(void);
int		beginswith_P(const char *s1, const char *s2);
    
#if 0
uint8_t PROGMEM ledvals[] = {0x01, 0x03, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xc0, 0x80};
static uint8_t dir = 0;
static volatile uint8_t leds = 0;
static uint8_t ledpos = 0;

INTERRUPT(SIG_OVERFLOW0) {
    if (!leds)
	return;

    /* Going up */
    if (dir == 0) {
	if (ledpos == 9) {
	    dir = 1;
	    TCNT0 = 0;
	    goto doleds;
	}

	ledpos++;
    } else {
	if (ledpos == 0) {
	    dir = 0;
	    TCNT0 = 0;
	    goto doleds;
	}

	ledpos--;
    }

  doleds:
    TCNT0 = 0;

    PORTA = pgm_read_byte(&ledvals[ledpos]);
}
#endif

void
usleep(uint16_t usec) {
    /* 4Mhz = 250ns per clock cycle */
    usec /= 2;
    if (usec < 1)
	return;
    
    while (usec--) 
	asm volatile (
	    ""
	    ::);
}

int
main(void) {
    uint8_t	ROM[8];
    char	cmdbuf[40];
    int		i;
    
    cli();
#if 0
    outp(0xff, DDRA);

    /* Timer Clock divisor - CK/1024 */
    outp(BV(CS00) | BV(CS02), TCCR0);
#endif
    outp(0xfe, DDRC);
    outp(0x00, PORTC);
    
    /* Init UART */
    outp(UART_BAUD_SELECT(UART_BAUD_RATE,XTAL_CPU), UBRR);

    /* Enable receiver and transmitter. Turn on transmit interrupts */
    outp(BV(RXEN) | BV(TXEN), UCR);

    uart_putsP(PSTR("\n\r\n\r===============\n\r"
		    "Inited!\n\r\n\r"));

    while (1) {
	uart_putsP(PSTR("> "));
	i = 0;
	while (1) {
	    cmdbuf[i] = tolower(uart_getc());
	    if (cmdbuf[i] == '\n' || cmdbuf[i] == '\r')
		break;
	    
	    /* Backspace */
	    if (cmdbuf[i] == 010) {
		if (i > 0) {
		    uart_putsP(PSTR("\010\040\010"));
		    i--;
		}
		continue;
	    }

	    /* Anything unprintable just ignore it */
	    if (!isprint(cmdbuf[i]))
		continue;
	    
	    uart_putc(cmdbuf[i]);
	    i++;
	    if (i == sizeof(cmdbuf)) {
		uart_putsP(PSTR("\n\rLine too long\n\r"));
		i = 0;
		continue;
	    }
	}
	cmdbuf[i + 1] = '\0';
	uart_putsP(PSTR("\n\r"));
	if (i == 0)
	    continue;

	if (cmdbuf[0] == '?') {
	    uart_putsP(PSTR("rs               Reset and check for presence\n\r"
			    "sr               Search the bus for ROMs\n\r"
			    "re               Read a bit\n\r"
			    "rb               Read a byte\n\r"
			    "wr bit           Write a bit\n\r"
			    "wb byte          Write a byte (hex)\n\r"
			    "wc cmd [ROMID]   Write command\n\r"
			    "te ROMID         Read the temperature from a DS1820\n\r"));
	    continue;
	}
	
	if (i < 2)
	    goto badcmd;
	
	if (cmdbuf[0] == 'r' && cmdbuf[1] == 's') {
	    uart_putsP(PSTR("Resetting... "));
	    
	    if (OWTouchReset() == 1)
		uart_putsP(PSTR("No presense\n\r"));
	    else
		uart_putsP(PSTR("Presense\n\r"));
	} else if (cmdbuf[0] == 'r' && cmdbuf[1] == 'e') {
	    if (OWReadBit())
		uart_putsP(PSTR("Read a 1\n\r"));
	    else
		uart_putsP(PSTR("Read a 0\n\r"));
	} else if (cmdbuf[0] == 'r' && cmdbuf[1] == 'b') {
	    sprintf_P(cmdbuf, PSTR("Read a 0x%02x\n\r"), OWReadByte());
	    uart_puts(cmdbuf);
	} else if (cmdbuf[0] == 'w' && cmdbuf[1] == 'r') {
	    int arg;
	    
	    if (sscanf_P(cmdbuf + 3, PSTR("%d"), &arg) != 1) {
		uart_putsP(PSTR("Unable to parse wr command\n\r"));
		continue;
	    }
	    
	    OWWriteBit(arg);
	    sprintf_P(cmdbuf, PSTR("Wrote a %d\n\r"), arg);
	    uart_puts(cmdbuf);
	} else if (cmdbuf[0] == 'w' && cmdbuf[1] == 'b') {
	    int arg;
	    
	    if (sscanf_P(cmdbuf + 3, PSTR("%2x"), &arg) != 1) {
		uart_putsP(PSTR("Unable to parse wb command\n\r"));
		continue;
	    }
	    
	    OWWriteByte(arg);
	    sprintf_P(cmdbuf, PSTR("Wrote a 0x%02x\n\r"), arg);
	    uart_puts(cmdbuf);
	} else if (cmdbuf[0] == 'w' && cmdbuf[1] == 'c') {
	    int		arg;

	    switch (sscanf_P(cmdbuf + 3, PSTR("%x %x:%x:%x:%x:%x:%x:%x:%x:%x"), &arg,
			     &ROM[0], &ROM[1], &ROM[2], &ROM[3], 
			     &ROM[4], &ROM[5], &ROM[6], &ROM[7])) {
		break;
		
	    case 1:
		OWSendCmd(NULL, arg);
		sprintf_P(cmdbuf, PSTR("Sent 0x%02x to all ROMS\n\r"), arg);
		uart_puts(cmdbuf);
		break;
		
	    case 9:
		OWSendCmd(ROM, arg);
		sprintf_P(cmdbuf, PSTR("Sent 0x%02x to ROM %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n\r"),
			  arg, ROM[0], ROM[1], ROM[2], ROM[3], 
			  ROM[4], ROM[5], ROM[6], ROM[7]);
		uart_puts(cmdbuf);
		
		break;
		
	    case 0:
	    default:
		uart_putsP(PSTR("Unable to parse wc command\n\r"));
		break;
	    }
	    
	    OWWriteByte(arg);
	    sprintf_P(cmdbuf, PSTR("Wrote a 0x%02x\n\r"), arg);
	    uart_puts(cmdbuf);
	} else if (cmdbuf[0] == 't' && cmdbuf[1] == 'e') {
	    uint8_t	crc;
	    uint16_t	temp;
	    uint8_t	buf[9];
	    
	    if (sscanf_P(cmdbuf + 3, PSTR("%x:%x:%x:%x:%x:%x:%x:%x:%x"),
			 &ROM[0], &ROM[1], &ROM[2], &ROM[3], 
			 &ROM[4], &ROM[5], &ROM[6], &ROM[7]) != 8) {
		uart_putsP(PSTR("Unable to parse ROM ID\n\r"));
		continue;
	    }
	    
	    if (ROM[0] != OW_FAMILY_TEMP) {
		uart_putsP(PSTR("ROM specified isn't a temperature sensor\n\r"));
		continue;
	    }
	    
	    OWSendCmd(ROM, OW_CONVERTT_CMD);
#if OW_DEBUG
	    uart_putsP(PSTR("Command sent, waiting\n\r"));
#endif
	    i = 0;
	    while (OWReadBit() == 0) {
		i++;
	    }
#if OW_DEBUG
	    sprintf_P(cmdbuf, PSTR("Temp comversion took %d cycles\n\r"), i);
	    uart_puts(cmdbuf);
#endif	
	    OWSendCmd(ROM, OW_RD_SCR_CMD);
	    crc = 0;
	    for (i = 0; i < 9; i++) {
		buf[i] = OWReadByte();
		if (i < 8)
		    OWCRC(buf[i], &crc);
	    }
	    
	    temp = buf[0];
	    temp |= (uint16_t)buf[1] << 8;
	    temp <<= 3;
	    
	    if (crc != buf[8]) {
		sprintf_P(cmdbuf, PSTR("CRC mismatch got %d vs calcd %d\n\r"), buf[8], crc);
		uart_puts(cmdbuf);
		continue;
	    }
	    
	    sprintf_P(cmdbuf, PSTR("temperature %d.%01d\n\r"),
		      temp >> 4, (temp << 12) / 6553);
	    uart_puts(cmdbuf);
	} else if (cmdbuf[0] == 's' && cmdbuf[1] == 'r') {
	    memset(ROM, 0, 8);
	    if (OWTouchReset()) {
		uart_putsP(PSTR("No devices on bus\n\r"));
		break;
	    }
	    if (OWFirst(ROM, 1, 0) == 0) {
		uart_putsP(PSTR("No module found\n\r"));
		break;
	    }
	    do {
		sprintf_P(cmdbuf, PSTR("%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n\r"), 
			  ROM[0],
			  ROM[1],
			  ROM[2],
			  ROM[3],
			  ROM[4],
			  ROM[5],
			  ROM[6],
			  ROM[7]);
		uart_puts(cmdbuf);
	    } while (OWNext(ROM, 1, 0));
#if 0

	} else if (cmdbuf[0] == 'l' && cmdbuf[1] == 'e' && cmdbuf[2] == 'd') {
	    if (leds == 0) {
		leds = 1;
		ledpos = 0;
		outp(0, TCNT0);
		sbi(TIMSK, TOIE0);
		sei();
		uart_putsP(PSTR("Starting\n\r"));
	    } else {
		leds = 0;
		ledpos = 0;
		PORTA = 0x00;
		cbi(TIMSK, TOIE0);
		cli();
		uart_putsP(PSTR("Stopping\n\r"));
	    }
#endif	    
	} else {
	  badcmd:
	    uart_putsP(PSTR("Unknown command, ? for a list\n\r"));
	}

    }
    
    return(0);
}

int
uart_putc(char c) {
    loop_until_bit_is_set(USR, UDRE);
    outp(c, UDR);

    return(0);
}

void
uart_putsP(const char *addr) {
    char c;

    while ((c = PRG_RDB((unsigned short)addr++)))
	uart_putc(c);
}

void
uart_puts(const char *addr) {
    while (*addr)
	uart_putc(*addr++);
}

int
uart_getc(void) {
    while (!(inp(USR) & 0x80))
	;
    
    return (inp(UDR));
}