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Larry Johnson9e2c3472007-12-27 09:52:17 -05001/*
Larry Johnson7754f332008-02-21 13:58:11 -05002 * (C) Copyright 2007-2008
Larry Johnson9e2c3472007-12-27 09:52:17 -05003 * Larry Johnson, lrj@acm.org
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 * National Semiconductor LM73 Temperature Sensor
31 */
32
33#include <common.h>
Larry Johnson9e2c3472007-12-27 09:52:17 -050034#include <i2c.h>
35#include <dtt.h>
36
37/*
38 * Device code
39 */
40#define DTT_I2C_DEV_CODE 0x48 /* National Semi's LM73 device */
Michal Simek6ecbb452008-07-11 11:50:53 +020041#define DTT_READ_TEMP 0x0
42#define DTT_CONFIG 0x1
43#define DTT_TEMP_HIGH 0x2
44#define DTT_TEMP_LOW 0x3
45#define DTT_CONTROL 0x4
46#define DTT_ID 0x7
Larry Johnson9e2c3472007-12-27 09:52:17 -050047
Larry Johnson7754f332008-02-21 13:58:11 -050048int dtt_read(int const sensor, int const reg)
Larry Johnson9e2c3472007-12-27 09:52:17 -050049{
50 int dlen;
Larry Johnson7754f332008-02-21 13:58:11 -050051 uint8_t data[2];
Larry Johnson9e2c3472007-12-27 09:52:17 -050052
53 /*
54 * Validate 'reg' param and get register size.
55 */
56 switch (reg) {
57 case DTT_CONFIG:
58 case DTT_CONTROL:
59 dlen = 1;
60 break;
61 case DTT_READ_TEMP:
62 case DTT_TEMP_HIGH:
63 case DTT_TEMP_LOW:
64 case DTT_ID:
65 dlen = 2;
66 break;
67 default:
68 return -1;
69 }
70 /*
Larry Johnson7754f332008-02-21 13:58:11 -050071 * Try to read the register at the calculated sensor address.
Larry Johnson9e2c3472007-12-27 09:52:17 -050072 */
Larry Johnson7754f332008-02-21 13:58:11 -050073 if (0 !=
74 i2c_read(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, dlen))
Larry Johnson9e2c3472007-12-27 09:52:17 -050075 return -1;
76 /*
77 * Handle 2 byte result.
78 */
79 if (2 == dlen)
Larry Johnson7754f332008-02-21 13:58:11 -050080 return (int)((unsigned)data[0] << 8 | (unsigned)data[1]);
Larry Johnson9e2c3472007-12-27 09:52:17 -050081
82 return (int)data[0];
83} /* dtt_read() */
84
Larry Johnson7754f332008-02-21 13:58:11 -050085int dtt_write(int const sensor, int const reg, int const val)
Larry Johnson9e2c3472007-12-27 09:52:17 -050086{
87 int dlen;
Larry Johnson7754f332008-02-21 13:58:11 -050088 uint8_t data[2];
Larry Johnson9e2c3472007-12-27 09:52:17 -050089
90 /*
91 * Validate 'reg' param and handle register size
92 */
93 switch (reg) {
94 case DTT_CONFIG:
95 case DTT_CONTROL:
96 dlen = 1;
Larry Johnson7754f332008-02-21 13:58:11 -050097 data[0] = (uint8_t) val;
Larry Johnson9e2c3472007-12-27 09:52:17 -050098 break;
99 case DTT_TEMP_HIGH:
100 case DTT_TEMP_LOW:
101 dlen = 2;
Larry Johnson7754f332008-02-21 13:58:11 -0500102 data[0] = (uint8_t) (val >> 8); /* MSB first */
103 data[1] = (uint8_t) val;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500104 break;
105 default:
106 return -1;
107 }
108 /*
Larry Johnson7754f332008-02-21 13:58:11 -0500109 * Write value to register at the calculated sensor address.
Larry Johnson9e2c3472007-12-27 09:52:17 -0500110 */
Larry Johnson7754f332008-02-21 13:58:11 -0500111 return 0 != i2c_write(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data,
112 dlen);
Larry Johnson9e2c3472007-12-27 09:52:17 -0500113} /* dtt_write() */
114
Larry Johnson7754f332008-02-21 13:58:11 -0500115static int _dtt_init(int const sensor)
Larry Johnson9e2c3472007-12-27 09:52:17 -0500116{
117 int val;
118
119 /*
120 * Validate the Identification register
121 */
122 if (0x0190 != dtt_read(sensor, DTT_ID))
Larry Johnson7754f332008-02-21 13:58:11 -0500123 return -1;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500124 /*
125 * Setup THIGH (upper-limit) and TLOW (lower-limit) registers
126 */
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200127 val = CONFIG_SYS_DTT_MAX_TEMP << 7;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500128 if (dtt_write(sensor, DTT_TEMP_HIGH, val))
Larry Johnson7754f332008-02-21 13:58:11 -0500129 return -1;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500130
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200131 val = CONFIG_SYS_DTT_MIN_TEMP << 7;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500132 if (dtt_write(sensor, DTT_TEMP_LOW, val))
Larry Johnson7754f332008-02-21 13:58:11 -0500133 return -1;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500134 /*
135 * Setup configuraton register
136 */
137 /* config = alert active low, disabled, and reset */
138 val = 0x64;
139 if (dtt_write(sensor, DTT_CONFIG, val))
Larry Johnson7754f332008-02-21 13:58:11 -0500140 return -1;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500141 /*
142 * Setup control/status register
143 */
144 /* control = temp resolution 0.25C */
145 val = 0x00;
146 if (dtt_write(sensor, DTT_CONTROL, val))
Larry Johnson7754f332008-02-21 13:58:11 -0500147 return -1;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500148
149 dtt_read(sensor, DTT_CONTROL); /* clear temperature flags */
150 return 0;
151} /* _dtt_init() */
152
153int dtt_init(void)
154{
155 int i;
156 unsigned char sensors[] = CONFIG_DTT_SENSORS;
157 const char *const header = "DTT: ";
158
159 for (i = 0; i < sizeof(sensors); i++) {
Larry Johnson7754f332008-02-21 13:58:11 -0500160 if (0 != _dtt_init(sensors[i]))
Larry Johnson9e2c3472007-12-27 09:52:17 -0500161 printf("%s%d FAILED INIT\n", header, i + 1);
162 else
163 printf("%s%d is %i C\n", header, i + 1,
164 dtt_get_temp(sensors[i]));
165 }
166 return 0;
167} /* dtt_init() */
168
Larry Johnson7754f332008-02-21 13:58:11 -0500169int dtt_get_temp(int const sensor)
Larry Johnson9e2c3472007-12-27 09:52:17 -0500170{
Larry Johnson7754f332008-02-21 13:58:11 -0500171 int const ret = dtt_read(sensor, DTT_READ_TEMP);
172
173 if (ret < 0) {
174 printf("DTT temperature read failed.\n");
175 return 0;
176 }
177 return (int)((int16_t) ret + 0x0040) >> 7;
Larry Johnson9e2c3472007-12-27 09:52:17 -0500178} /* dtt_get_temp() */