mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-08-16 07:28:57 +00:00
245 lines
7.2 KiB
C
245 lines
7.2 KiB
C
|
/*
|
||
|
* Copyright (c) 2009, University of Colombo School of Computing
|
||
|
* 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.
|
||
|
* 3. Neither the name of the Institute nor the names of its contributors
|
||
|
* may be used to endorse or promote products derived from this software
|
||
|
* without specific prior written permission.
|
||
|
*
|
||
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 THE INSTITUTE 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.
|
||
|
*
|
||
|
* This file is part of the Contiki operating system.
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* Device driver for the Dallas Semiconductor DS2401 chip. Heavily
|
||
|
* based on the application note 126 "1-Wire Communications Through
|
||
|
* Software".
|
||
|
*
|
||
|
* http://www.maxim-ic.com/appnotes.cfm/appnote_number/126
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* For now we stuff in Crossbow Technology, Inc's unique OUI.
|
||
|
* 00:1A:4C Crossbow Technology, Inc
|
||
|
*
|
||
|
* The EUI-64 is a concatenation of the 24-bit OUI value assigned by
|
||
|
* the IEEE Registration Authority and a 40-bit extension identifier
|
||
|
* assigned by the organization with that OUI assignment.
|
||
|
*/
|
||
|
|
||
|
#include <avr/io.h>
|
||
|
#include <string.h>
|
||
|
#include "contiki.h"
|
||
|
|
||
|
#include "ds2401.h"
|
||
|
|
||
|
unsigned char ds2401_id[8];
|
||
|
|
||
|
/* 1-wire is at PortA.4 */
|
||
|
#define SERIAL_ID_PIN_READ PINA
|
||
|
#define SERIAL_ID_PIN_MASK _BV(4)
|
||
|
#define SERIAL_ID_PxOUT PORTA
|
||
|
#define SERIAL_ID_PxDIR DDRA
|
||
|
|
||
|
#define SET_PIN_INPUT() (SERIAL_ID_PxDIR &= ~SERIAL_ID_PIN_MASK)
|
||
|
#define SET_PIN_OUTPUT() (SERIAL_ID_PxDIR |= SERIAL_ID_PIN_MASK)
|
||
|
|
||
|
#define OUTP_0() (SERIAL_ID_PxOUT &= ~SERIAL_ID_PIN_MASK)
|
||
|
#define OUTP_1() (SERIAL_ID_PxOUT |= SERIAL_ID_PIN_MASK)
|
||
|
|
||
|
#define PIN_INIT() do{ \
|
||
|
SET_PIN_INPUT(); \
|
||
|
OUTP_0(); \
|
||
|
} while(0)
|
||
|
|
||
|
|
||
|
/* Drive the one wire interface low */
|
||
|
#define OW_DRIVE() do { \
|
||
|
SET_PIN_OUTPUT(); \
|
||
|
OUTP_0(); \
|
||
|
} while (0)
|
||
|
|
||
|
/* Release the one wire by turning on the internal pull-up. */
|
||
|
#define OW_RELEASE() do { \
|
||
|
SET_PIN_INPUT(); \
|
||
|
OUTP_1(); \
|
||
|
} while (0)
|
||
|
|
||
|
/* Read one bit. */
|
||
|
#define INP() (SERIAL_ID_PIN_READ & SERIAL_ID_PIN_MASK)
|
||
|
|
||
|
/*
|
||
|
* Delay times in us.
|
||
|
*/
|
||
|
#define tA 6 /* min-5, recommended-6, max-15 */
|
||
|
#define tB 64 /* min-59, recommended-64, max-N/A */
|
||
|
#define tC 60 /* min-60, recommended-60, max-120 */
|
||
|
#define tD 10 /* min-5.3, recommended-10, max-N/A */
|
||
|
#define tE 9 /* min-0.3, recommended-9, max-9.3 */
|
||
|
#define tF 55 /* min-50, recommended-55, max-N/A */
|
||
|
#define tG 0 /* min-0, recommended-0, max-0 */
|
||
|
#define tH 480 /* min-480, recommended-480, max-640 */
|
||
|
#define tI 70 /* min-60.3, recommended-70, max-75.3 */
|
||
|
#define tJ 410 /* min-410, recommended-410, max-N/A */
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/*
|
||
|
* The delay caused by calling the delay_loop is given by the following
|
||
|
* formula.
|
||
|
* delay(us) = (4n + 1)/XTAL
|
||
|
* where n is the number of iterations and XTAL is the clock frequency(in MHz).
|
||
|
* TODO: Moving the delay_loop to dev/clock.c
|
||
|
*/
|
||
|
static void
|
||
|
delay_loop(uint16_t __count)
|
||
|
{
|
||
|
asm volatile ("1: sbiw %0,1" "\n\t"
|
||
|
"brne 1b"
|
||
|
: "=w" (__count)
|
||
|
: "0" (__count)
|
||
|
);
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/*
|
||
|
* This macro relies on the compiler doing the arithmetic during compile time
|
||
|
* for the needed iterations.!!
|
||
|
* In MICAz, XTAL = 7.3728 MHz
|
||
|
*/
|
||
|
#define udelay(u) delay_loop(((7.3728F * u)-1)/4)
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
static uint8_t
|
||
|
reset(void)
|
||
|
{
|
||
|
uint8_t result;
|
||
|
OW_DRIVE();
|
||
|
udelay(500); /* 480 < tH < 640 */
|
||
|
OW_RELEASE(); /* Releases the bus */
|
||
|
udelay(tI);
|
||
|
result = INP();
|
||
|
udelay(tJ);
|
||
|
return result;
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
static void
|
||
|
write_byte(uint8_t byte)
|
||
|
{
|
||
|
uint8_t i = 7;
|
||
|
do {
|
||
|
if (byte & 0x01) {
|
||
|
OW_DRIVE();
|
||
|
udelay(tA);
|
||
|
OW_RELEASE(); /* Releases the bus */
|
||
|
udelay(tB);
|
||
|
} else {
|
||
|
OW_DRIVE();
|
||
|
udelay(tC);
|
||
|
OW_RELEASE(); /* Releases the bus */
|
||
|
udelay(tD);
|
||
|
}
|
||
|
if (i == 0)
|
||
|
return;
|
||
|
i--;
|
||
|
byte >>= 1;
|
||
|
} while (1);
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
static unsigned
|
||
|
read_byte(void)
|
||
|
{
|
||
|
unsigned result = 0;
|
||
|
int i = 7;
|
||
|
do {
|
||
|
OW_DRIVE();
|
||
|
udelay(tA);
|
||
|
OW_RELEASE(); /* Releases the bus */
|
||
|
udelay(tE);
|
||
|
if (INP())
|
||
|
result |= 0x80; /* LSbit first */
|
||
|
udelay(tF);
|
||
|
if (i == 0)
|
||
|
return result;
|
||
|
i--;
|
||
|
result >>= 1;
|
||
|
} while (1);
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/* Polynomial ^8 + ^5 + ^4 + 1 */
|
||
|
static unsigned
|
||
|
crc8_add(unsigned acc, unsigned byte)
|
||
|
{
|
||
|
int i;
|
||
|
acc ^= byte;
|
||
|
for (i = 0; i < 8; i++)
|
||
|
if (acc & 1)
|
||
|
acc = (acc >> 1) ^ 0x8c;
|
||
|
else
|
||
|
acc >>= 1;
|
||
|
|
||
|
return acc;
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
int
|
||
|
ds2401_init()
|
||
|
{
|
||
|
int i;
|
||
|
uint8_t volatile sreg;
|
||
|
unsigned family, crc, acc;
|
||
|
|
||
|
PIN_INIT();
|
||
|
|
||
|
sreg = SREG; /* Save status register before disabling interrupts. */
|
||
|
cli(); /* Disable interrupts. */
|
||
|
|
||
|
if (reset() == 0) {
|
||
|
write_byte(0x33); /* Read ROM command. */
|
||
|
family = read_byte();
|
||
|
for (i = 7; i >= 2; i--) {
|
||
|
ds2401_id[i] = read_byte();
|
||
|
}
|
||
|
crc = read_byte();
|
||
|
|
||
|
SREG = sreg; /* Enable interrupts. */
|
||
|
|
||
|
if(family != 0x01) {
|
||
|
goto fail;
|
||
|
}
|
||
|
acc = crc8_add(0x0, family);
|
||
|
for (i = 7; i >= 2; i--) {
|
||
|
acc = crc8_add(acc, ds2401_id[i]);
|
||
|
}
|
||
|
if (acc == crc) {
|
||
|
/* 00:1A:4C OUI for Crossbow Technology, Inc. */
|
||
|
ds2401_id[0] = 0x00;
|
||
|
ds2401_id[1] = 0x1A;
|
||
|
ds2401_id[2] = 0x4C;
|
||
|
return 1; /* Success! */
|
||
|
}
|
||
|
} else {
|
||
|
SREG = sreg; /* Enable interrupts. */
|
||
|
}
|
||
|
|
||
|
fail:
|
||
|
memset(ds2401_id, 0x0, sizeof(ds2401_id));
|
||
|
return 0; /* Fail! */
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|