[people/ms/u-boot.git] / drivers / hwmon / ds1775.c

/*
 * 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 DS1775 Digital Thermometer and Thermostat
 */

#include <common.h>

#include <i2c.h>
#include <dtt.h>

#define DTT_I2C_DEV_CODE	CONFIG_SYS_I2C_DTT_ADDR /* Dallas Semi's DS1775 device code */
#define DTT_READ_TEMP		0x0
#define DTT_CONFIG		0x1
#define DTT_TEMP_HYST		0x2
#define DTT_TEMP_OS		0x3

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 ds1775 */

	/*
	 * Prepare to handle 2 byte result
	 */
	if ((reg == DTT_READ_TEMP) ||
	    (reg == DTT_TEMP_OS) || (reg == DTT_TEMP_HYST))
		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];
}


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_OS) || (reg == DTT_TEMP_HYST)) {
		dlen = 2;
		data[0] = (char)((val >> 8) & 0xff); /* MSB first */
		data[1] = (char)(val & 0xff);
	} 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;
}


static int _dtt_init(int sensor)
{
	int val;

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

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

	/*
	 * Setup configuraton register
	 *
	 * Fault Tolerance limits 4, Thermometer resolution bits is 9,
	 * Polarity = Active Low,continuous conversion mode, Thermostat
	 * mode is interrupt mode
	 */
	val = 0xa;
	if (dtt_write(sensor, DTT_CONFIG, val) != 0)
		return 1;
	udelay(50000);			/* Max 50ms */

	return 0;
}


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);
}


int dtt_get_temp(int sensor)
{
	return (dtt_read(sensor, DTT_READ_TEMP) / 256);
}
Commit	Line	Data
d4024bb7 JO	1	/*
	2	* This program is free software; you can redistribute it and/or
	3	* modify it under the terms of the GNU General Public License as
	4	* published by the Free Software Foundation; either version 2 of
	5	* the License, or (at your option) any later version.
	6	*
	7	* This program is distributed in the hope that it will be useful,
	8	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	9	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	10	* GNU General Public License for more details.
	11	*
	12	* You should have received a copy of the GNU General Public License
	13	* along with this program; if not, write to the Free Software
	14	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	15	* MA 02111-1307 USA
	16	*/
	17
	18	/*
	19	* Dallas Semiconductor's DS1775 Digital Thermometer and Thermostat
	20	*/
	21
	22	#include <common.h>
	23
d4024bb7 JO	24	#include <i2c.h>
	25	#include <dtt.h>
	26
6d0f6bcf	27	#define DTT_I2C_DEV_CODE CONFIG_SYS_I2C_DTT_ADDR /* Dallas Semi's DS1775 device code */
6ecbb45b MS	28	#define DTT_READ_TEMP 0x0
	29	#define DTT_CONFIG 0x1
	30	#define DTT_TEMP_HYST 0x2
	31	#define DTT_TEMP_OS 0x3
d4024bb7 JO	32
	33	int dtt_read(int sensor, int reg)
	34	{
	35	int dlen;
	36	uchar data[2];
	37
	38	/*
	39	* Calculate sensor address and command
	40	*/
	41	sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* Calculate addr of ds1775 */
	42
	43	/*
	44	* Prepare to handle 2 byte result
	45	*/
	46	if ((reg == DTT_READ_TEMP) \|\|
	47	(reg == DTT_TEMP_OS) \|\| (reg == DTT_TEMP_HYST))
	48	dlen = 2;
	49	else
	50	dlen = 1;
	51
	52	/*
	53	* Now try to read the register
	54	*/
	55	if (i2c_read(sensor, reg, 1, data, dlen) != 0)
	56	return 1;
	57
	58	/*
	59	* Handle 2 byte result
	60	*/
	61	if (dlen == 2)
	62	return ((int)((short)data[1] + (((short)data[0]) << 8)));
	63
	64	return (int) data[0];
	65	}
	66
	67
	68	int dtt_write(int sensor, int reg, int val)
	69	{
	70	int dlen;
	71	uchar data[2];
	72
	73	/*
	74	* Calculate sensor address and register
	75	*/
	76	sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
	77
	78	/*
	79	* Handle various data sizes
	80	*/
	81	if ((reg == DTT_READ_TEMP) \|\|
	82	(reg == DTT_TEMP_OS) \|\| (reg == DTT_TEMP_HYST)) {
	83	dlen = 2;
	84	data[0] = (char)((val >> 8) & 0xff); /* MSB first */
	85	data[1] = (char)(val & 0xff);
	86	} else {
	87	dlen = 1;
	88	data[0] = (char)(val & 0xff);
	89	}
	90
	91	/*
	92	* Write value to device
	93	*/
	94	if (i2c_write(sensor, reg, 1, data, dlen) != 0)
	95	return 1;
96
97	return 0;
98	}
99
100
101	static int _dtt_init(int sensor)
102	{
103	int val;
104
105	/*
106	* Setup High Temp
107	*/
6d0f6bcf	108	val = ((CONFIG_SYS_DTT_MAX_TEMP * 2) << 7) & 0xff80;
d4024bb7 JO	109	if (dtt_write(sensor, DTT_TEMP_OS, val) != 0)
	110	return 1;
	111	udelay(50000); /* Max 50ms */
	112
	113	/*
	114	* Setup Low Temp - hysteresis
	115	*/
6d0f6bcf	116	val = (((CONFIG_SYS_DTT_MAX_TEMP - CONFIG_SYS_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
d4024bb7 JO	117	if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0)
	118	return 1;
	119	udelay(50000); /* Max 50ms */
	120
	121	/*
	122	* Setup configuraton register
	123	*
	124	* Fault Tolerance limits 4, Thermometer resolution bits is 9,
	125	* Polarity = Active Low,continuous conversion mode, Thermostat
	126	* mode is interrupt mode
	127	*/
	128	val = 0xa;
	129	if (dtt_write(sensor, DTT_CONFIG, val) != 0)
	130	return 1;
	131	udelay(50000); /* Max 50ms */
	132
	133	return 0;
	134	}
	135
	136
	137	int dtt_init (void)
	138	{
	139	int i;
	140	unsigned char sensors[] = CONFIG_DTT_SENSORS;
	141
	142	for (i = 0; i < sizeof(sensors); i++) {
	143	if (_dtt_init(sensors[i]) != 0)
	144	printf("DTT%d: FAILED\n", i+1);
	145	else
	146	printf("DTT%d: %i C\n", i+1, dtt_get_temp(sensors[i]));
	147	}
	148
	149	return (0);
	150	}
	151
	152
	153	int dtt_get_temp(int sensor)
	154	{
	155	return (dtt_read(sensor, DTT_READ_TEMP) / 256);
	156	}