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wdenkc6097192002-11-03 00:24:07 +00001/*
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>
wdenkc6097192002-11-03 00:24:07 +000029#include <i2c.h>
30#include <dtt.h>
31
wdenkc6097192002-11-03 00:24:07 +000032/*
33 * Device code
34 */
Victor Gallardo9ebbb542008-09-09 15:13:29 -070035#if defined(CFG_I2C_DTT_ADDR)
36#define DTT_I2C_DEV_CODE CFG_I2C_DTT_ADDR
37#else
wdenkc6097192002-11-03 00:24:07 +000038#define DTT_I2C_DEV_CODE 0x48 /* ON Semi's LM75 device */
Victor Gallardo9ebbb542008-09-09 15:13:29 -070039#endif
Michal Simek6ecbb452008-07-11 11:50:53 +020040#define DTT_READ_TEMP 0x0
41#define DTT_CONFIG 0x1
42#define DTT_TEMP_HYST 0x2
43#define DTT_TEMP_SET 0x3
wdenkc6097192002-11-03 00:24:07 +000044
45int dtt_read(int sensor, int reg)
46{
Heiko Schocher12f16782008-10-15 09:37:04 +020047 int dlen;
48 uchar data[2];
wdenkc6097192002-11-03 00:24:07 +000049
Stefan Roese4d91d1d2008-05-16 11:06:06 +020050#ifdef CONFIG_DTT_AD7414
Heiko Schocher12f16782008-10-15 09:37:04 +020051 /*
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);
Stefan Roese4d91d1d2008-05-16 11:06:06 +020061#endif
62
Heiko Schocher12f16782008-10-15 09:37:04 +020063 /* Validate 'reg' param */
64 if((reg < 0) || (reg > 3))
65 return -1;
wdenkc6097192002-11-03 00:24:07 +000066
Heiko Schocher12f16782008-10-15 09:37:04 +020067 /* Calculate sensor address and register. */
68 sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
wdenkc6097192002-11-03 00:24:07 +000069
Heiko Schocher12f16782008-10-15 09:37:04 +020070 /* Prepare to handle 2 byte result. */
71 if ((reg == DTT_READ_TEMP) ||
72 (reg == DTT_TEMP_HYST) ||
73 (reg == DTT_TEMP_SET))
74 dlen = 2;
75 else
76 dlen = 1;
wdenkc6097192002-11-03 00:24:07 +000077
Heiko Schocher12f16782008-10-15 09:37:04 +020078 /* Now try to read the register. */
79 if (i2c_read(sensor, reg, 1, data, dlen) != 0)
80 return -1;
wdenkc6097192002-11-03 00:24:07 +000081
Heiko Schocher12f16782008-10-15 09:37:04 +020082 /* Handle 2 byte result. */
83 if (dlen == 2)
84 return ((int)((short)data[1] + (((short)data[0]) << 8)));
wdenkc6097192002-11-03 00:24:07 +000085
Heiko Schocher12f16782008-10-15 09:37:04 +020086 return (int)data[0];
wdenkc6097192002-11-03 00:24:07 +000087} /* dtt_read() */
88
89
90int dtt_write(int sensor, int reg, int val)
91{
Heiko Schocher12f16782008-10-15 09:37:04 +020092 int dlen;
93 uchar data[2];
wdenkc6097192002-11-03 00:24:07 +000094
Heiko Schocher12f16782008-10-15 09:37:04 +020095 /* Validate 'reg' param */
96 if ((reg < 0) || (reg > 3))
97 return 1;
wdenkc6097192002-11-03 00:24:07 +000098
Heiko Schocher12f16782008-10-15 09:37:04 +020099 /* Calculate sensor address and register. */
100 sensor = DTT_I2C_DEV_CODE + (sensor & 0x07);
wdenkc6097192002-11-03 00:24:07 +0000101
Heiko Schocher12f16782008-10-15 09:37:04 +0200102 /* Handle 2 byte values. */
103 if ((reg == DTT_READ_TEMP) ||
104 (reg == DTT_TEMP_HYST) ||
105 (reg == DTT_TEMP_SET)) {
106 dlen = 2;
107 data[0] = (char)((val >> 8) & 0xff); /* MSB first */
108 data[1] = (char)(val & 0xff);
109 } else {
110 dlen = 1;
111 data[0] = (char)(val & 0xff);
112 }
wdenkc6097192002-11-03 00:24:07 +0000113
Heiko Schocher12f16782008-10-15 09:37:04 +0200114 /* Write value to register. */
115 if (i2c_write(sensor, reg, 1, data, dlen) != 0)
116 return 1;
wdenkc6097192002-11-03 00:24:07 +0000117
Heiko Schocher12f16782008-10-15 09:37:04 +0200118 return 0;
wdenkc6097192002-11-03 00:24:07 +0000119} /* dtt_write() */
120
121
122static int _dtt_init(int sensor)
123{
Heiko Schocher12f16782008-10-15 09:37:04 +0200124 int val;
wdenkc6097192002-11-03 00:24:07 +0000125
Heiko Schocher12f16782008-10-15 09:37:04 +0200126 /* Setup TSET ( trip point ) register */
127 val = ((CFG_DTT_MAX_TEMP * 2) << 7) & 0xff80; /* trip */
128 if (dtt_write(sensor, DTT_TEMP_SET, val) != 0)
129 return 1;
wdenkc6097192002-11-03 00:24:07 +0000130
Heiko Schocher12f16782008-10-15 09:37:04 +0200131 /* Setup THYST ( untrip point ) register - Hysteresis */
132 val = (((CFG_DTT_MAX_TEMP - CFG_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
133 if (dtt_write(sensor, DTT_TEMP_HYST, val) != 0)
134 return 1;
wdenkc6097192002-11-03 00:24:07 +0000135
Heiko Schocher12f16782008-10-15 09:37:04 +0200136 /* Setup configuraton register */
Stefan Roese887e2ec2006-09-07 11:51:23 +0200137#ifdef CONFIG_DTT_AD7414
Heiko Schocher12f16782008-10-15 09:37:04 +0200138 /* config = alert active low and disabled */
139 val = 0x60;
Stefan Roese887e2ec2006-09-07 11:51:23 +0200140#else
Heiko Schocher12f16782008-10-15 09:37:04 +0200141 /* config = 6 sample integration, int mode, active low, and enable */
142 val = 0x18;
Stefan Roese887e2ec2006-09-07 11:51:23 +0200143#endif
Heiko Schocher12f16782008-10-15 09:37:04 +0200144 if (dtt_write(sensor, DTT_CONFIG, val) != 0)
145 return 1;
wdenkc6097192002-11-03 00:24:07 +0000146
Heiko Schocher12f16782008-10-15 09:37:04 +0200147 return 0;
wdenkc6097192002-11-03 00:24:07 +0000148} /* _dtt_init() */
149
150
151int dtt_init (void)
152{
Heiko Schocher12f16782008-10-15 09:37:04 +0200153 int i;
154 unsigned char sensors[] = CONFIG_DTT_SENSORS;
155 const char *const header = "DTT: ";
156 int old_bus;
wdenkc6097192002-11-03 00:24:07 +0000157
Heiko Schocher8e442df2008-10-15 09:37:34 +0200158 /* switch to correct I2C bus */
159 old_bus = I2C_GET_BUS();
160 I2C_SET_BUS(CFG_DTT_BUS_NUM);
161
Heiko Schocher12f16782008-10-15 09:37:04 +0200162 for (i = 0; i < sizeof(sensors); i++) {
wdenkc6097192002-11-03 00:24:07 +0000163 if (_dtt_init(sensors[i]) != 0)
Heiko Schocher12f16782008-10-15 09:37:04 +0200164 printf("%s%d FAILED INIT\n", header, i+1);
wdenkc6097192002-11-03 00:24:07 +0000165 else
Heiko Schocher12f16782008-10-15 09:37:04 +0200166 printf("%s%d is %i C\n", header, i+1,
167 dtt_get_temp(sensors[i]));
168 }
Heiko Schocher8e442df2008-10-15 09:37:34 +0200169 /* switch back to original I2C bus */
170 I2C_SET_BUS(old_bus);
wdenkc6097192002-11-03 00:24:07 +0000171
Heiko Schocher12f16782008-10-15 09:37:04 +0200172 return (0);
wdenkc6097192002-11-03 00:24:07 +0000173} /* dtt_init() */
174
175int dtt_get_temp(int sensor)
176{
Heiko Schocher12f16782008-10-15 09:37:04 +0200177 int const ret = dtt_read(sensor, DTT_READ_TEMP);
Larry Johnsond01b8472008-02-21 13:58:16 -0500178
Heiko Schocher12f16782008-10-15 09:37:04 +0200179 if (ret < 0) {
180 printf("DTT temperature read failed.\n");
181 return 0;
182 }
183 return (int)((int16_t) ret / 256);
wdenkc6097192002-11-03 00:24:07 +0000184} /* dtt_get_temp() */