blob: c83a3cdf6367266fbf16ebda77214d18dc960ce4 [file] [log] [blame]
Heiko Schocher6dedf3d2006-12-21 16:14:48 +01001/*
2 * (C) Copyright 2006
3 * Heiko Schocher, DENX Software Enginnering <hs@denx.de>
4 *
5 * based on dtt/lm75.c which is ...
6 *
7 * (C) Copyright 2001
8 * Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net
9 *
10 * See file CREDITS for list of people who contributed to this
11 * project.
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License as
15 * published by the Free Software Foundation; either version 2 of
16 * the License, or (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 * MA 02111-1307 USA
27 */
28
29/*
30 * On Semiconductor's LM81 Temperature Sensor
31 */
32
33#include <common.h>
34
35#ifdef CONFIG_DTT_LM81
36#if !defined(CFG_EEPROM_PAGE_WRITE_ENABLE) || \
37 (CFG_EEPROM_PAGE_WRITE_BITS < 1)
38# 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"
39#endif
40
41#include <i2c.h>
42#include <dtt.h>
43
44/*
45 * Device code
46 */
47#define DTT_I2C_DEV_CODE 0x2c /* ON Semi's LM81 device */
48
49int dtt_read(int sensor, int reg)
50{
51 int dlen = 1;
52 uchar data[2];
53
54 /*
55 * Calculate sensor address and register.
56 */
57 sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */
58
59 /*
60 * Now try to read the register.
61 */
62 if (i2c_read(sensor, reg, 1, data, dlen) != 0)
63 return -1;
64
65 return (int)data[0];
66} /* dtt_read() */
67
68
69int dtt_write(int sensor, int reg, int val)
70{
71 uchar data;
72
73 /*
74 * Calculate sensor address and register.
75 */
76 sensor = DTT_I2C_DEV_CODE + (sensor & 0x03); /* calculate address of lm81 */
77
78 data = (char)(val & 0xff);
79
80 /*
81 * Write value to register.
82 */
Heiko Schochera443d312007-01-14 13:35:31 +010083 if (i2c_write(sensor, reg, 1, &data, 1) != 0)
Heiko Schocher6dedf3d2006-12-21 16:14:48 +010084 return 1;
85
86 return 0;
87} /* dtt_write() */
88
89#define DTT_MANU 0x3e
90#define DTT_REV 0x3f
Heiko Schochera443d312007-01-14 13:35:31 +010091#define DTT_CONFIG 0x40
Heiko Schocher6dedf3d2006-12-21 16:14:48 +010092#define DTT_ADR 0x48
93
94static int _dtt_init(int sensor)
95{
96 int man;
97 int adr;
98 int rev;
99
100 if (dtt_write (sensor, DTT_CONFIG, 0x01) < 0)
101 return 1;
Heiko Schochera443d312007-01-14 13:35:31 +0100102 /* The LM81 needs 400ms to get the correct values ... */
103 udelay (400000);
Heiko Schocher6dedf3d2006-12-21 16:14:48 +0100104 man = dtt_read (sensor, DTT_MANU);
105 if (man != 0x01)
106 return 1;
107 adr = dtt_read (sensor, DTT_ADR);
108 if (adr < 0)
109 return 1;
110 rev = dtt_read (sensor, DTT_REV);
111 if (adr < 0)
112 return 1;
113
114 printf ("DTT: Found LM81@%x Rev: %d\n", adr, rev);
Heiko Schocher6dedf3d2006-12-21 16:14:48 +0100115 return 0;
116} /* _dtt_init() */
117
118
119int dtt_init (void)
120{
121 int i;
122 unsigned char sensors[] = CONFIG_DTT_SENSORS;
123 const char *const header = "DTT: ";
124
125 for (i = 0; i < sizeof(sensors); i++) {
126 if (_dtt_init(sensors[i]) != 0)
127 printf("%s%d FAILED INIT\n", header, i+1);
128 else
129 printf("%s%d is %i C\n", header, i+1,
130 dtt_get_temp(sensors[i]));
131 }
132
133 return (0);
134} /* dtt_init() */
135
136#define TEMP_FROM_REG(temp) \
137 ((temp)<256?((((temp)&0x1fe) >> 1) * 10) + ((temp) & 1) * 5: \
138 ((((temp)&0x1fe) >> 1) -255) * 10 - ((temp) & 1) * 5) \
139
140int dtt_get_temp(int sensor)
141{
142 int val = dtt_read (sensor, DTT_READ_TEMP);
143 int tmpcnf = dtt_read (sensor, DTT_CONFIG_TEMP);
144
145 return (TEMP_FROM_REG((val << 1) + ((tmpcnf & 0x80) >> 7))) / 10;
146} /* dtt_get_temp() */
147
148#endif /* CONFIG_DTT_LM81 */