1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
/*
* (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>
#ifdef CONFIG_DTT_LM75
#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_LM75"
#endif
#include <i2c.h>
#include <dtt.h>
/*
* Device code
*/
#define DTT_I2C_DEV_CODE 0x48 /* ON Semi's LM75 device */
int dtt_read(int sensor, int reg)
{
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); /* calculate address of lm75 */
/*
* 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); /* calculate address of lm75 */
/*
* 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 = ((CFG_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 = (((CFG_DTT_MAX_TEMP - CFG_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: ";
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)
{
return (dtt_read(sensor, DTT_READ_TEMP) / 256);
} /* dtt_get_temp() */
#endif /* CONFIG_DTT_LM75 */
|
