[people/ms/u-boot.git] / drivers / hwmon / lm75.c

/*
 * (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 LM75 Temperature Sensor
 */

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

/*
 * Device code
 */
#if defined(CONFIG_SYS_I2C_DTT_ADDR)
#define DTT_I2C_DEV_CODE CONFIG_SYS_I2C_DTT_ADDR
#else
#define DTT_I2C_DEV_CODE 0x48			/* ON Semi's LM75 device */
#endif
#define DTT_READ_TEMP		0x0
#define DTT_CONFIG		0x1
#define DTT_TEMP_HYST		0x2
#define DTT_TEMP_SET		0x3

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

#ifdef CONFIG_DTT_AD7414
	/*
	 * On AD7414 the first value upon bootup is not read correctly.
	 * This is most likely because of the 800ms update time of the
	 * temp register in normal update mode. To get current values
	 * each time we issue the "dtt" command including upon powerup
	 * we switch into one-short mode.
	 *
	 * Issue one-shot mode command
	 */
	dtt_write(sensor, DTT_CONFIG, 0x64);
#endif

	/* Validate 'reg' param */
	if((reg < 0) || (reg > 3))
		return -1;

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

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

	/* Validate 'reg' param */
	if ((reg < 0) || (reg > 3))
		return 1;

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

	/* Handle 2 byte values. */
	if ((reg == DTT_READ_TEMP) ||
		(reg == DTT_TEMP_HYST) ||
		(reg == DTT_TEMP_SET)) {
			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 register. */
	if (i2c_write(sensor, reg, 1, data, dlen) != 0)
		return 1;

	return 0;
} /* dtt_write() */


static int _dtt_init(int sensor)
{
	int val;

	/* Setup TSET ( trip point ) register */
	val = ((CONFIG_SYS_DTT_MAX_TEMP * 2) << 7) & 0xff80; /* trip */
	if (dtt_write(sensor, DTT_TEMP_SET, val) != 0)
		return 1;

	/* Setup THYST ( untrip point ) register - 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;

	/* Setup configuraton register */
#ifdef CONFIG_DTT_AD7414
	/* config = alert active low and disabled */
	val = 0x60;
#else
	/* config = 6 sample integration, int mode, active low, and enable */
	val = 0x18;
#endif
	if (dtt_write(sensor, DTT_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:   ";
	int old_bus;

	/* switch to correct I2C bus */
	old_bus = I2C_GET_BUS();
	I2C_SET_BUS(CONFIG_SYS_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]));
	}
	/* switch back to original I2C bus */
	I2C_SET_BUS(old_bus);

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

int dtt_get_temp(int sensor)
{
	int const ret = dtt_read(sensor, DTT_READ_TEMP);

	if (ret < 0) {
		printf("DTT temperature read failed.\n");
		return 0;
	}
	return (int)((int16_t) ret / 256);
} /* dtt_get_temp() */
Commit	Line	Data
c609719b WD	1	/*
	2	* (C) Copyright 2001
	3	* Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net
	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	* On Semiconductor's LM75 Temperature Sensor
	26	*/
	27
	28	#include <common.h>
c609719b WD	29	#include <i2c.h>
	30	#include <dtt.h>
	31
c609719b WD	32	/*
	33	* Device code
	34	*/
6d0f6bcf JCPV	35	#if defined(CONFIG_SYS_I2C_DTT_ADDR)
6d0f6bcf JCPV	36	#define DTT_I2C_DEV_CODE CONFIG_SYS_I2C_DTT_ADDR
9ebbb54f	37	#else
c609719b	38	#define DTT_I2C_DEV_CODE 0x48 /* ON Semi's LM75 device */
9ebbb54f	39	#endif
6ecbb45b MS	40	#define DTT_READ_TEMP 0x0
	41	#define DTT_CONFIG 0x1
	42	#define DTT_TEMP_HYST 0x2
	43	#define DTT_TEMP_SET 0x3
c609719b WD	44
	45	int dtt_read(int sensor, int reg)
	46	{
12f16781 HS	47	int dlen;
12f16781 HS	48	uchar data[2];
c609719b	49
4d91d1df	50	#ifdef CONFIG_DTT_AD7414
12f16781 HS	51	/*
	52	* On AD7414 the first value upon bootup is not read correctly.
	53	* This is most likely because of the 800ms update time of the
	54	* temp register in normal update mode. To get current values
	55	* each time we issue the "dtt" command including upon powerup
	56	* we switch into one-short mode.
	57	*
	58	* Issue one-shot mode command
	59	*/
	60	dtt_write(sensor, DTT_CONFIG, 0x64);
4d91d1df SR	61	#endif
4d91d1df SR	62
12f16781 HS	63	/* Validate 'reg' param */
	64	if((reg < 0) \|\| (reg > 3))
	65	return -1;
	66
	67	/* Calculate sensor address and register. */
	68	sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
	69
	70	/* Prepare to handle 2 byte result. */
	71	if ((reg == DTT_READ_TEMP) \|\|
	72	(reg == DTT_TEMP_HYST) \|\|
	73	(reg == DTT_TEMP_SET))
	74	dlen = 2;
	75	else
	76	dlen = 1;
	77
	78	/* Now try to read the register. */
	79	if (i2c_read(sensor, reg, 1, data, dlen) != 0)
	80	return -1;
	81
	82	/* Handle 2 byte result. */
	83	if (dlen == 2)
	84	return ((int)((short)data[1] + (((short)data[0]) << 8)));
	85
	86	return (int)data[0];
c609719b WD	87	} /* dtt_read() */
	88
	89
	90	int dtt_write(int sensor, int reg, int val)
	91	{
12f16781 HS	92	int dlen;
	93	uchar data[2];
	94
	95	/* Validate 'reg' param */
	96	if ((reg < 0) \|\| (reg > 3))
	97	return 1;
	98
	99	/* Calculate sensor address and register. */
	100	sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
	101
	102	/* Handle 2 byte values. */
	103	if ((reg == DTT_READ_TEMP) \|\|
	104	(reg == DTT_TEMP_HYST) \|\|
	105	(reg == DTT_TEMP_SET)) {
	106	dlen = 2;
	107	data[0] = (char)((val >> 8) & 0xff); /* MSB first */
	108	data[1] = (char)(val & 0xff);
	109	} else {
	110	dlen = 1;
	111	data[0] = (char)(val & 0xff);
	112	}
	113
	114	/* Write value to register. */
	115	if (i2c_write(sensor, reg, 1, data, dlen) != 0)
	116	return 1;
	117
	118	return 0;
c609719b WD	119	} /* dtt_write() */
	120
	121
	122	static int _dtt_init(int sensor)
	123	{
12f16781 HS	124	int val;
	125
	126	/* Setup TSET ( trip point ) register */
6d0f6bcf	127	val = ((CONFIG_SYS_DTT_MAX_TEMP * 2) << 7) & 0xff80; /* trip */
12f16781 HS	128	if (dtt_write(sensor, DTT_TEMP_SET, val) != 0)
	129	return 1;
	130
	131	/* Setup THYST ( untrip point ) register - Hysteresis */
6d0f6bcf	132	val = (((CONFIG_SYS_DTT_MAX_TEMP - CONFIG_SYS_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
12f16781 HS	133	if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0)
	134	return 1;
	135
	136	/* Setup configuraton register */
887e2ec9	137	#ifdef CONFIG_DTT_AD7414
12f16781 HS	138	/* config = alert active low and disabled */
12f16781 HS	139	val = 0x60;
887e2ec9	140	#else
12f16781 HS	141	/* config = 6 sample integration, int mode, active low, and enable */
12f16781 HS	142	val = 0x18;
887e2ec9	143	#endif
12f16781 HS	144	if (dtt_write(sensor, DTT_CONFIG, val) != 0)
12f16781 HS	145	return 1;
c609719b	146
12f16781	147	return 0;
c609719b WD	148	} /* _dtt_init() */
	149
	150
	151	int dtt_init (void)
	152	{
12f16781 HS	153	int i;
	154	unsigned char sensors[] = CONFIG_DTT_SENSORS;
	155	const char *const header = "DTT: ";
	156	int old_bus;
c609719b	157
8e442df4 HS	158	/* switch to correct I2C bus */
8e442df4 HS	159	old_bus = I2C_GET_BUS();
6d0f6bcf	160	I2C_SET_BUS(CONFIG_SYS_DTT_BUS_NUM);
8e442df4	161
12f16781	162	for (i = 0; i < sizeof(sensors); i++) {
c609719b	163	if (_dtt_init(sensors[i]) != 0)
12f16781	164	printf("%s%d FAILED INIT\n", header, i+1);
c609719b	165	else
12f16781 HS	166	printf("%s%d is %i C\n", header, i+1,
	167	dtt_get_temp(sensors[i]));
	168	}
8e442df4 HS	169	/* switch back to original I2C bus */
8e442df4 HS	170	I2C_SET_BUS(old_bus);
c609719b	171
12f16781	172	return (0);
c609719b WD	173	} /* dtt_init() */
	174
	175	int dtt_get_temp(int sensor)
	176	{
12f16781	177	int const ret = dtt_read(sensor, DTT_READ_TEMP);
d01b847c	178
12f16781 HS	179	if (ret < 0) {
	180	printf("DTT temperature read failed.\n");
	181	return 0;
	182	}
	183	return (int)((int16_t) ret / 256);
c609719b	184	} /* dtt_get_temp() */