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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> | |
29 | ||
30 | #ifdef CONFIG_DTT_LM75 | |
31 | #if !defined(CFG_EEPROM_PAGE_WRITE_ENABLE) || \ | |
32 | (CFG_EEPROM_PAGE_WRITE_BITS < 1) | |
33 | # 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" | |
34 | #endif | |
35 | ||
36 | #include <i2c.h> | |
37 | #include <dtt.h> | |
38 | ||
39 | ||
40 | /* | |
41 | * Device code | |
42 | */ | |
43 | #define DTT_I2C_DEV_CODE 0x48 /* ON Semi's LM75 device */ | |
44 | ||
45 | int dtt_read(int sensor, int reg) | |
46 | { | |
47 | int dlen; | |
48 | uchar data[2]; | |
49 | ||
4d91d1df SR |
50 | #ifdef CONFIG_DTT_AD7414 |
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); | |
61 | #endif | |
62 | ||
c609719b WD |
63 | /* |
64 | * Validate 'reg' param | |
65 | */ | |
66 | if((reg < 0) || (reg > 3)) | |
67 | return -1; | |
68 | ||
69 | /* | |
70 | * Calculate sensor address and register. | |
71 | */ | |
72 | sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate address of lm75 */ | |
73 | ||
74 | /* | |
75 | * Prepare to handle 2 byte result. | |
76 | */ | |
77 | if ((reg == DTT_READ_TEMP) || | |
78 | (reg == DTT_TEMP_HYST) || | |
79 | (reg == DTT_TEMP_SET)) | |
80 | dlen = 2; | |
81 | else | |
82 | dlen = 1; | |
83 | ||
84 | /* | |
85 | * Now try to read the register. | |
86 | */ | |
87 | if (i2c_read(sensor, reg, 1, data, dlen) != 0) | |
88 | return -1; | |
89 | ||
90 | /* | |
91 | * Handle 2 byte result. | |
92 | */ | |
93 | if (dlen == 2) | |
94 | return ((int)((short)data[1] + (((short)data[0]) << 8))); | |
95 | ||
96 | ||
97 | return (int)data[0]; | |
98 | } /* dtt_read() */ | |
99 | ||
100 | ||
101 | int dtt_write(int sensor, int reg, int val) | |
102 | { | |
103 | int dlen; | |
104 | uchar data[2]; | |
105 | ||
106 | /* | |
107 | * Validate 'reg' param | |
108 | */ | |
109 | if ((reg < 0) || (reg > 3)) | |
110 | return 1; | |
111 | ||
112 | /* | |
113 | * Calculate sensor address and register. | |
114 | */ | |
115 | sensor = DTT_I2C_DEV_CODE + (sensor & 0x07); /* calculate address of lm75 */ | |
116 | ||
117 | /* | |
118 | * Handle 2 byte values. | |
119 | */ | |
120 | if ((reg == DTT_READ_TEMP) || | |
121 | (reg == DTT_TEMP_HYST) || | |
122 | (reg == DTT_TEMP_SET)) { | |
123 | dlen = 2; | |
124 | data[0] = (char)((val >> 8) & 0xff); /* MSB first */ | |
125 | data[1] = (char)(val & 0xff); | |
126 | } else { | |
127 | dlen = 1; | |
128 | data[0] = (char)(val & 0xff); | |
129 | } | |
130 | ||
131 | /* | |
132 | * Write value to register. | |
133 | */ | |
134 | if (i2c_write(sensor, reg, 1, data, dlen) != 0) | |
135 | return 1; | |
136 | ||
137 | return 0; | |
138 | } /* dtt_write() */ | |
139 | ||
140 | ||
141 | static int _dtt_init(int sensor) | |
142 | { | |
143 | int val; | |
144 | ||
145 | /* | |
146 | * Setup TSET ( trip point ) register | |
147 | */ | |
148 | val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80; /* trip */ | |
149 | if (dtt_write(sensor, DTT_TEMP_SET, val) != 0) | |
150 | return 1; | |
151 | ||
152 | /* | |
153 | * Setup THYST ( untrip point ) register - Hysteresis | |
154 | */ | |
155 | val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80; | |
156 | if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0) | |
157 | return 1; | |
158 | ||
159 | /* | |
160 | * Setup configuraton register | |
161 | */ | |
887e2ec9 SR |
162 | #ifdef CONFIG_DTT_AD7414 |
163 | /* config = alert active low and disabled */ | |
164 | val = 0x60; | |
165 | #else | |
c609719b WD |
166 | /* config = 6 sample integration, int mode, active low, and enable */ |
167 | val = 0x18; | |
887e2ec9 | 168 | #endif |
c609719b WD |
169 | if (dtt_write(sensor, DTT_CONFIG, val) != 0) |
170 | return 1; | |
171 | ||
172 | return 0; | |
173 | } /* _dtt_init() */ | |
174 | ||
175 | ||
176 | int dtt_init (void) | |
177 | { | |
178 | int i; | |
179 | unsigned char sensors[] = CONFIG_DTT_SENSORS; | |
180 | const char *const header = "DTT: "; | |
181 | ||
182 | for (i = 0; i < sizeof(sensors); i++) { | |
183 | if (_dtt_init(sensors[i]) != 0) | |
184 | printf("%s%d FAILED INIT\n", header, i+1); | |
185 | else | |
186 | printf("%s%d is %i C\n", header, i+1, | |
187 | dtt_get_temp(sensors[i])); | |
188 | } | |
189 | ||
190 | return (0); | |
191 | } /* dtt_init() */ | |
192 | ||
193 | int dtt_get_temp(int sensor) | |
194 | { | |
d01b847c LJ |
195 | int const ret = dtt_read(sensor, DTT_READ_TEMP); |
196 | ||
197 | if (ret < 0) { | |
198 | printf("DTT temperature read failed.\n"); | |
199 | return 0; | |
200 | } | |
201 | return (int)((int16_t) ret / 256); | |
c609719b WD |
202 | } /* dtt_get_temp() */ |
203 | ||
204 | #endif /* CONFIG_DTT_LM75 */ |