text: /*
   * (C) Copyright 2003
   * Murray Jensen, CSIRO-MIT, Murray.Jensen@csiro.au
   *
   * 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
   */
  
  /*
   * Analog Devices's ADM1021
   * "Low Cost Microprocessor System Temperature Monitor"
   */
  
  #include <common.h>
  
  #include <i2c.h>
  #include <dtt.h>
  
  #define DTT_READ_LOC_VALUE	0x00
  #define DTT_READ_REM_VALUE	0x01
  #define DTT_READ_STATUS		0x02
  #define DTT_READ_CONFIG		0x03
  #define DTT_READ_CONVRATE	0x04
  #define DTT_READ_LOC_HIGHLIM	0x05
  #define DTT_READ_LOC_LOWLIM	0x06
  #define DTT_READ_REM_HIGHLIM	0x07
  #define DTT_READ_REM_LOWLIM	0x08
  #define DTT_READ_DEVID		0xfe
  
  #define DTT_WRITE_CONFIG	0x09
  #define DTT_WRITE_CONVRATE	0x0a
  #define DTT_WRITE_LOC_HIGHLIM	0x0b
  #define DTT_WRITE_LOC_LOWLIM	0x0c
  #define DTT_WRITE_REM_HIGHLIM	0x0d
  #define DTT_WRITE_REM_LOWLIM	0x0e
  #define DTT_WRITE_ONESHOT	0x0f
  
  #define DTT_STATUS_BUSY		0x80	/* 1=ADC Converting */
  #define DTT_STATUS_LHIGH	0x40	/* 1=Local High Temp Limit Tripped */
  #define DTT_STATUS_LLOW		0x20	/* 1=Local Low Temp Limit Tripped */
  #define DTT_STATUS_RHIGH	0x10	/* 1=Remote High Temp Limit Tripped */
  #define DTT_STATUS_RLOW		0x08	/* 1=Remote Low Temp Limit Tripped */
  #define DTT_STATUS_OPEN		0x04	/* 1=Remote Sensor Open-Circuit */
  
  #define DTT_CONFIG_ALERT_MASKED	0x80	/* 0=ALERT Enabled, 1=ALERT Masked */
  #define DTT_CONFIG_STANDBY	0x40	/* 0=Run, 1=Standby */
  
  #define DTT_ADM1021_DEVID	0x41
  
  typedef
  	struct {
  		uint i2c_addr:7;	/* 7bit i2c chip address */
  		uint conv_rate:3;	/* conversion rate */
  		uint enable_alert:1;	/* enable alert output pin */
  		uint enable_local:1;	/* enable internal temp sensor */
  		uint max_local:8;	/* internal temp maximum */
  		uint min_local:8;	/* internal temp minimum */
  		uint enable_remote:1;	/* enable remote temp sensor */
  		uint max_remote:8;	/* remote temp maximum */
  		uint min_remote:8;	/* remote temp minimum */
  	}
  dtt_cfg_t;
  
  dtt_cfg_t dttcfg[] = CFG_DTT_ADM1021;
  
  int
  dtt_read (int sensor, int reg)
  {
  	dtt_cfg_t *dcp = &dttcfg[sensor >> 1];
  	uchar data;
  
  	if (i2c_read(dcp->i2c_addr, reg, 1, &data, 1) != 0)
  		return -1;
  
  	return (int)data;
  } /* dtt_read() */
  
  int
  dtt_write (int sensor, int reg, int val)
  {
  	dtt_cfg_t *dcp = &dttcfg[sensor >> 1];
  	uchar data;
  
  	data = (uchar)(val & 0xff);
  
  	if (i2c_write(dcp->i2c_addr, reg, 1, &data, 1) != 0)
  		return 1;
  
  	return 0;
  } /* dtt_write() */
  
  static int
  _dtt_init (int sensor)
  {
  	dtt_cfg_t *dcp = &dttcfg[sensor >> 1];
  	int reg, val;
  
  	if (((sensor & 1) == 0 ? dcp->enable_local : dcp->enable_remote) == 0)
  		return 1;	/* sensor is disabled (or rather ignored) */
  
  	/*
  	 * Setup High Limit register
  	 */
  	if ((sensor & 1) == 0) {
  		reg = DTT_WRITE_LOC_HIGHLIM;
  		val = dcp->max_local;
  	}
  	else {
  		reg = DTT_WRITE_REM_HIGHLIM;
  		val = dcp->max_remote;
  	}
  	if (dtt_write (sensor, reg, val) != 0)
  		return 1;
  
  	/*
  	 * Setup Low Limit register
  	 */
  	if ((sensor & 1) == 0) {
  		reg = DTT_WRITE_LOC_LOWLIM;
  		val = dcp->min_local;
  	}
  	else {
  		reg = DTT_WRITE_REM_LOWLIM;
  		val = dcp->min_remote;
  	}
  	if (dtt_write (sensor, reg, val) != 0)
  		return 1;
  
  	/* shouldn't hurt if the rest gets done twice */
  
  	/*
  	 * Setup Conversion Rate register
  	 */
  	if (dtt_write (sensor, DTT_WRITE_CONVRATE, dcp->conv_rate) != 0)
  		return 1;
  
  	/*
  	 * Setup configuraton register
  	 */
  	val = 0;				/* running */
  	if (dcp->enable_alert == 0)
  		val |= DTT_CONFIG_ALERT_MASKED;	/* mask ALERT pin */
  	if (dtt_write (sensor, DTT_WRITE_CONFIG, val) != 0)
  		return 1;
  
  	return 0;
  } /* _dtt_init() */
  
  int
  dtt_init (void)
  {
  	int i;
  	unsigned char sensors[] = CONFIG_DTT_SENSORS;
  	const char *const header = "DTT:   ";
  
  	/* switch to correct I2C bus */
  	I2C_SET_BUS(CFG_DTT_BUS_NUM);
  
  	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() */
  
  int
  dtt_get_temp (int sensor)
  {
  	signed char val;
  
  	if ((sensor & 1) == 0)
  		val = dtt_read(sensor, DTT_READ_LOC_VALUE);
  	else
  		val = dtt_read(sensor, DTT_READ_REM_VALUE);
  
  	return (int) val;
  } /* dtt_get_temp() */
  