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
|
/*
* (C) Copyright 2007-2008
* Larry Johnson, lrj@acm.org
*
* based on dtt/lm75.c which is ...
*
* (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
*/
/*
* National Semiconductor LM73 Temperature Sensor
*/
#include <common.h>
#include <i2c.h>
#include <dtt.h>
/*
* Device code
*/
#define DTT_I2C_DEV_CODE 0x48 /* National Semi's LM73 device */
#define DTT_READ_TEMP 0x0
#define DTT_CONFIG 0x1
#define DTT_TEMP_HIGH 0x2
#define DTT_TEMP_LOW 0x3
#define DTT_CONTROL 0x4
#define DTT_ID 0x7
int dtt_read(int const sensor, int const reg)
{
int dlen;
uint8_t data[2];
/*
* Validate 'reg' param and get register size.
*/
switch (reg) {
case DTT_CONFIG:
case DTT_CONTROL:
dlen = 1;
break;
case DTT_READ_TEMP:
case DTT_TEMP_HIGH:
case DTT_TEMP_LOW:
case DTT_ID:
dlen = 2;
break;
default:
return -1;
}
/*
* Try to read the register at the calculated sensor address.
*/
if (0 !=
i2c_read(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, dlen))
return -1;
/*
* Handle 2 byte result.
*/
if (2 == dlen)
return (int)((unsigned)data[0] << 8 | (unsigned)data[1]);
return (int)data[0];
} /* dtt_read() */
int dtt_write(int const sensor, int const reg, int const val)
{
int dlen;
uint8_t data[2];
/*
* Validate 'reg' param and handle register size
*/
switch (reg) {
case DTT_CONFIG:
case DTT_CONTROL:
dlen = 1;
data[0] = (uint8_t) val;
break;
case DTT_TEMP_HIGH:
case DTT_TEMP_LOW:
dlen = 2;
data[0] = (uint8_t) (val >> 8); /* MSB first */
data[1] = (uint8_t) val;
break;
default:
return -1;
}
/*
* Write value to register at the calculated sensor address.
*/
return 0 != i2c_write(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data,
dlen);
} /* dtt_write() */
static int _dtt_init(int const sensor)
{
int val;
/*
* Validate the Identification register
*/
if (0x0190 != dtt_read(sensor, DTT_ID))
return -1;
/*
* Setup THIGH (upper-limit) and TLOW (lower-limit) registers
*/
val = CFG_DTT_MAX_TEMP << 7;
if (dtt_write(sensor, DTT_TEMP_HIGH, val))
return -1;
val = CFG_DTT_MIN_TEMP << 7;
if (dtt_write(sensor, DTT_TEMP_LOW, val))
return -1;
/*
* Setup configuraton register
*/
/* config = alert active low, disabled, and reset */
val = 0x64;
if (dtt_write(sensor, DTT_CONFIG, val))
return -1;
/*
* Setup control/status register
*/
/* control = temp resolution 0.25C */
val = 0x00;
if (dtt_write(sensor, DTT_CONTROL, val))
return -1;
dtt_read(sensor, DTT_CONTROL); /* clear temperature flags */
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 (0 != _dtt_init(sensors[i]))
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 const 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 + 0x0040) >> 7;
} /* dtt_get_temp() */
|
