[people/ms/u-boot.git] / dtt / ds1621.c

/*
 * (C) Copyright 2001
 * Erik Theisen,  Wave 7 Optics, etheisen@mindspring.com.
 *
 * 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
 */

/*
 * Dallas Semiconductor's DS1621 Digital Thermometer and Thermostat.
 */

#include <common.h>

#ifdef CONFIG_DTT_DS1621
#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_DS1621"
#endif
#include <i2c.h>
#include <dtt.h>

/*
 * Device code
 */
#define DTT_I2C_DEV_CODE 0x48			/* Dallas Semi's DS1621 */

int dtt_read(int sensor, int reg)
{
    int dlen;
    uchar data[2];

    /*
     * Calculate sensor address and command.
     *
     */
    sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* Calculate addr of ds1621*/

    /*
     * Prepare to handle 2 byte result.
     */
    if ((reg == DTT_READ_TEMP) ||
	(reg == DTT_TEMP_HIGH) || (reg == DTT_TEMP_LOW))
	dlen = 2;
    else
	dlen = 1;

    /*
     * Now try to read the register.
     */
    if (i2c_read(sensor, reg, 1, data, dlen) != 0)
	return 1;

    /*
     * Handle 2 byte result.
     */
    if (dlen == 2)
	return ((int)((short)data[1] + (((short)data[0]) << 8)));

    return (int)data[0];
} /* dtt_read() */


int dtt_write(int sensor, int reg, int val)
{
    int dlen;
    uchar data[2];

    /*
     * Calculate sensor address and register.
     *
     */
    sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);

    /*
     * Handle various data sizes.
     */
    if ((reg == DTT_READ_TEMP) ||
	(reg == DTT_TEMP_HIGH) || (reg == DTT_TEMP_LOW)) {
	dlen = 2;
	data[0] = (char)((val >> 8) & 0xff);	/* MSB first */
	data[1] = (char)(val & 0xff);
    }
    else if ((reg == DTT_WRITE_START_CONV) || (reg == DTT_WRITE_STOP_CONV)) {
	dlen = 0;
	data[0] = (char)0;
	data[1] = (char)0;
    }
    else {
	dlen = 1;
	data[0] = (char)(val & 0xff);
    }

    /*
     * Write value to device.
     */
    if (i2c_write(sensor, reg, 1, data, dlen) != 0)
	return 1;

    return 0;
} /* dtt_write() */


static int _dtt_init(int sensor)
{
    int val;

    /*
     * Setup High Temp.
     */
    val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80;
    if (dtt_write(sensor, DTT_TEMP_HIGH, val) != 0)
	return 1;
    udelay(50000);				/* Max 50ms */

    /*
     * Setup Low Temp - hysteresis.
     */
    val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
    if (dtt_write(sensor, DTT_TEMP_LOW, val) != 0)
	return 1;
    udelay(50000);				/* Max 50ms */

    /*
     * Setup configuraton register
     *
     * Clear THF & TLF, Reserved = 1, Polarity = Active Low, One Shot = YES
     *
     * We run in polled mode, since there isn't any way to know if this
     * lousy device is ready to provide temperature readings on power up.
     */
    val = 0x9;
    if (dtt_write(sensor, DTT_CONFIG, val) != 0)
	return 1;
    udelay(50000);				/* Max 50ms */

    return 0;
} /* _dtt_init() */


int dtt_init (void)
{
    int i;
    unsigned char sensors[] = CONFIG_DTT_SENSORS;

    for (i = 0; i < sizeof(sensors); i++) {
	if (_dtt_init(sensors[i]) != 0)
	    printf("DTT%d:  FAILED\n", i+1);
	else
	    printf("DTT%d:  %i C\n", i+1, dtt_get_temp(sensors[i]));
    }

    return (0);
} /* dtt_init() */


int dtt_get_temp(int sensor)
{
    int i;

    /*
     * Start a conversion, may take up to 1 second.
     */
    dtt_write(sensor, DTT_WRITE_START_CONV, 0);
    for (i = 0; i <= 10; i++) {
	udelay(100000);
	if (dtt_read(sensor, DTT_CONFIG) & 0x80)
	    break;
    }

    return (dtt_read(sensor, DTT_READ_TEMP) / 256);
} /* dtt_get_temp() */


#endif /* CONFIG_DTT_DS1621 */
Commit	Line	Data
c609719b WD	1	/*
	2	* (C) Copyright 2001
	3	* Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
	4	*
	5	* See file CREDITS for list of people who contributed to this
	6	* project.
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License as
	10	* published by the Free Software Foundation; either version 2 of
	11	* the License, or (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	21	* MA 02111-1307 USA
	22	*/
	23
	24	/*
	25	* Dallas Semiconductor's DS1621 Digital Thermometer and Thermostat.
	26	*/
	27
	28	#include <common.h>
	29
	30	#ifdef CONFIG_DTT_DS1621
	31	#if !defined(CFG_EEPROM_PAGE_WRITE_ENABLE) \|\| \
8bde7f77	32	(CFG_EEPROM_PAGE_WRITE_BITS < 1)
c609719b WD	33	# error "CFG_EEPROM_PAGE_WRITE_ENABLE must be defined and CFG_EEPROM_PAGE_WRITE_BITS must be greater than 1 to use CONFIG_DTT_DS1621"
	34	#endif
	35	#include <i2c.h>
	36	#include <dtt.h>
	37
	38	/*
	39	* Device code
	40	*/
	41	#define DTT_I2C_DEV_CODE 0x48 /* Dallas Semi's DS1621 */
	42
	43	int dtt_read(int sensor, int reg)
	44	{
	45	int dlen;
	46	uchar data[2];
	47
	48	/*
	49	* Calculate sensor address and command.
	50	*
	51	*/
	52	sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* Calculate addr of ds1621*/
	53
	54	/*
	55	* Prepare to handle 2 byte result.
	56	*/
	57	if ((reg == DTT_READ_TEMP) \|\|
	58	(reg == DTT_TEMP_HIGH) \|\| (reg == DTT_TEMP_LOW))
	59	dlen = 2;
	60	else
	61	dlen = 1;
	62
	63	/*
	64	* Now try to read the register.
	65	*/
	66	if (i2c_read(sensor, reg, 1, data, dlen) != 0)
	67	return 1;
	68
	69	/*
	70	* Handle 2 byte result.
	71	*/
	72	if (dlen == 2)
	73	return ((int)((short)data[1] + (((short)data[0]) << 8)));
	74
	75	return (int)data[0];
	76	} /* dtt_read() */
	77
	78
	79	int dtt_write(int sensor, int reg, int val)
	80	{
	81	int dlen;
	82	uchar data[2];
	83
	84	/*
	85	* Calculate sensor address and register.
	86	*
	87	*/
8564acf9	88	sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
c609719b WD	89
	90	/*
	91	* Handle various data sizes.
	92	*/
	93	if ((reg == DTT_READ_TEMP) \|\|
	94	(reg == DTT_TEMP_HIGH) \|\| (reg == DTT_TEMP_LOW)) {
	95	dlen = 2;
	96	data[0] = (char)((val >> 8) & 0xff); /* MSB first */
	97	data[1] = (char)(val & 0xff);
	98	}
	99	else if ((reg == DTT_WRITE_START_CONV) \|\| (reg == DTT_WRITE_STOP_CONV)) {
	100	dlen = 0;
	101	data[0] = (char)0;
	102	data[1] = (char)0;
	103	}
	104	else {
	105	dlen = 1;
	106	data[0] = (char)(val & 0xff);
	107	}
	108
	109	/*
	110	* Write value to device.
	111	*/
	112	if (i2c_write(sensor, reg, 1, data, dlen) != 0)
	113	return 1;
	114
	115	return 0;
	116	} /* dtt_write() */
	117
	118
	119	static int _dtt_init(int sensor)
	120	{
	121	int val;
	122
	123	/*
	124	* Setup High Temp.
	125	*/
	126	val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80;
	127	if (dtt_write(sensor, DTT_TEMP_HIGH, val) != 0)
	128	return 1;
	129	udelay(50000); /* Max 50ms */
	130
	131	/*
	132	* Setup Low Temp - hysteresis.
	133	*/
	134	val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
	135	if (dtt_write(sensor, DTT_TEMP_LOW, val) != 0)
	136	return 1;
	137	udelay(50000); /* Max 50ms */
	138
	139	/*
	140	* Setup configuraton register
	141	*
	142	* Clear THF & TLF, Reserved = 1, Polarity = Active Low, One Shot = YES
	143	*
	144	* We run in polled mode, since there isn't any way to know if this
	145	* lousy device is ready to provide temperature readings on power up.
	146	*/
	147	val = 0x9;
	148	if (dtt_write(sensor, DTT_CONFIG, val) != 0)
	149	return 1;
	150	udelay(50000); /* Max 50ms */
	151
	152	return 0;
153	} /* _dtt_init() */
154
155
156	int dtt_init (void)
157	{
158	int i;
159	unsigned char sensors[] = CONFIG_DTT_SENSORS;
160
161	for (i = 0; i < sizeof(sensors); i++) {
162	if (_dtt_init(sensors[i]) != 0)
163	printf("DTT%d: FAILED\n", i+1);
164	else
165	printf("DTT%d: %i C\n", i+1, dtt_get_temp(sensors[i]));
166	}
167
168	return (0);
169	} /* dtt_init() */
170
171
172	int dtt_get_temp(int sensor)
173	{
174	int i;
175
176	/*
177	* Start a conversion, may take up to 1 second.
178	*/
179	dtt_write(sensor, DTT_WRITE_START_CONV, 0);
180	for (i = 0; i <= 10; i++) {
181	udelay(100000);
182	if (dtt_read(sensor, DTT_CONFIG) & 0x80)
183	break;
184	}
185
186	return (dtt_read(sensor, DTT_READ_TEMP) / 256);
187	} /* dtt_get_temp() */
188
189
190	#endif /* CONFIG_DTT_DS1621 */