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/*
* (C) Copyright 2006
* Heiko Schocher, DENX Software Enginnering <hs@denx.de>
*
* based on dtt/lm75.c which is ...
*
* (C) Copyright 2001
* Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 2 of
* the License, or (at your option) any later version.
*
* 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
*/
/*
* On Semiconductor's LM81 Temperature Sensor
*/
#include <common.h>
#if !defined(CFG_EEPROM_PAGE_WRITE_ENABLE) || \
(CFG_EEPROM_PAGE_WRITE_BITS < 1)
# error "CFG_EEPROM_PAGE_WRITE_ENABLE must be defined and CFG_EEPROM_PAGE_WRITE_BITS must be greater than 1 to use CONFIG_DTT_LM81"
#endif
#include <i2c.h>
#include <dtt.h>
/*
* Device code
*/
#define DTT_I2C_DEV_CODE 0x2c /* ON Semi's LM81 device */
#define DTT_READ_TEMP 0x27
#define DTT_CONFIG_TEMP 0x4b
#define DTT_TEMP_MAX 0x39
#define DTT_TEMP_HYST 0x3a
#define DTT_CONFIG 0x40
int dtt_read(int sensor, int reg)
{
int dlen = 1;
uchar data[2];
/*
* Calculate sensor address and register.
*/
sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */
/*
* Now try to read the register.
*/
if (i2c_read(sensor, reg, 1, data, dlen) != 0)
return -1;
return (int)data[0];
} /* dtt_read() */
int dtt_write(int sensor, int reg, int val)
{
uchar data;
/*
* Calculate sensor address and register.
*/
sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */
data = (char)(val & 0xff);
/*
* Write value to register.
*/
if (i2c_write(sensor, reg, 1, &data, 1) != 0)
return 1;
return 0;
} /* dtt_write() */
#define DTT_MANU 0x3e
#define DTT_REV 0x3f
#define DTT_CONFIG 0x40
#define DTT_ADR 0x48
static int _dtt_init(int sensor)
{
int man;
int adr;
int rev;
if (dtt_write (sensor, DTT_CONFIG, 0x01) < 0)
return 1;
/* The LM81 needs 400ms to get the correct values ... */
udelay (400000);
man = dtt_read (sensor, DTT_MANU);
if (man != 0x01)
return 1;
adr = dtt_read (sensor, DTT_ADR);
if (adr < 0)
return 1;
rev = dtt_read (sensor, DTT_REV);
if (adr < 0)
return 1;
printf ("DTT: Found LM81@%x Rev: %d\n", adr, rev);
return 0;
} /* _dtt_init() */
int dtt_init (void)
{
int i;
unsigned char sensors[] = CONFIG_DTT_SENSORS;
const char *const header = "DTT: ";
for (i = 0; i < sizeof(sensors); i++) {
if (_dtt_init(sensors[i]) != 0)
printf("%s%d FAILED INIT\n", header, i+1);
else
printf("%s%d is %i C\n", header, i+1,
dtt_get_temp(sensors[i]));
}
return (0);
} /* dtt_init() */
#define TEMP_FROM_REG(temp) \
((temp)<256?((((temp)&0x1fe) >> 1) * 10) + ((temp) & 1) * 5: \
((((temp)&0x1fe) >> 1) -255) * 10 - ((temp) & 1) * 5) \
int dtt_get_temp(int sensor)
{
int val = dtt_read (sensor, DTT_READ_TEMP);
int tmpcnf = dtt_read (sensor, DTT_CONFIG_TEMP);
return (TEMP_FROM_REG((val << 1) + ((tmpcnf & 0x80) >> 7))) / 10;
} /* dtt_get_temp() */
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