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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/* $OpenBSD: owtemp.c,v 1.11 2008/12/26 18:17:25 todd Exp $ */
/*
* Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* 1-Wire temperature family type device driver.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sensors.h>
#include <dev/onewire/onewiredevs.h>
#include <dev/onewire/onewirereg.h>
#include <dev/onewire/onewirevar.h>
/* Commands */
#define DS1920_CMD_CONVERT 0x44
#define DS1920_CMD_READ_SCRATCHPAD 0xbe
/* Scratchpad layout */
#define DS1920_SP_TEMP_LSB 0
#define DS1920_SP_TEMP_MSB 1
#define DS1920_SP_TH 2
#define DS1920_SP_TL 3
#define DS18B20_SP_CONFIG 4
#define DS1920_SP_COUNT_REMAIN 6
#define DS1920_SP_COUNT_PERC 7
#define DS1920_SP_CRC 8
struct owtemp_softc {
struct device sc_dev;
void * sc_onewire;
u_int64_t sc_rom;
struct ksensor sc_sensor;
struct ksensordev sc_sensordev;
struct sensor_task *sc_sensortask;
struct rwlock sc_lock;
};
int owtemp_match(struct device *, void *, void *);
void owtemp_attach(struct device *, struct device *, void *);
int owtemp_detach(struct device *, int);
int owtemp_activate(struct device *, enum devact);
void owtemp_update(void *);
struct cfattach owtemp_ca = {
sizeof(struct owtemp_softc),
owtemp_match,
owtemp_attach,
owtemp_detach,
owtemp_activate
};
struct cfdriver owtemp_cd = {
NULL, "owtemp", DV_DULL
};
static const struct onewire_matchfam owtemp_fams[] = {
{ ONEWIRE_FAMILY_DS1920 },
{ ONEWIRE_FAMILY_DS18B20 }
};
int
owtemp_match(struct device *parent, void *match, void *aux)
{
return (onewire_matchbyfam(aux, owtemp_fams,
sizeof(owtemp_fams) /sizeof(owtemp_fams[0])));
}
void
owtemp_attach(struct device *parent, struct device *self, void *aux)
{
struct owtemp_softc *sc = (struct owtemp_softc *)self;
struct onewire_attach_args *oa = aux;
sc->sc_onewire = oa->oa_onewire;
sc->sc_rom = oa->oa_rom;
/* Initialize sensor */
strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
sizeof(sc->sc_sensordev.xname));
sc->sc_sensor.type = SENSOR_TEMP;
snprintf(sc->sc_sensor.desc, sizeof(sc->sc_sensor.desc), "sn %012llx",
ONEWIRE_ROM_SN(oa->oa_rom));
sc->sc_sensortask = sensor_task_register(sc, owtemp_update, 5);
if (sc->sc_sensortask == NULL) {
printf(": unable to register update task\n");
return;
}
sensor_attach(&sc->sc_sensordev, &sc->sc_sensor);
sensordev_install(&sc->sc_sensordev);
rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);
printf("\n");
}
int
owtemp_detach(struct device *self, int flags)
{
struct owtemp_softc *sc = (struct owtemp_softc *)self;
rw_enter_write(&sc->sc_lock);
sensordev_deinstall(&sc->sc_sensordev);
if (sc->sc_sensortask != NULL)
sensor_task_unregister(sc->sc_sensortask);
rw_exit_write(&sc->sc_lock);
return (0);
}
int
owtemp_activate(struct device *self, enum devact act)
{
return (0);
}
void
owtemp_update(void *arg)
{
struct owtemp_softc *sc = arg;
u_int8_t data[9];
int16_t temp;
int count_perc, count_remain, val;
rw_enter_write(&sc->sc_lock);
onewire_lock(sc->sc_onewire, 0);
if (onewire_reset(sc->sc_onewire) != 0)
goto done;
onewire_matchrom(sc->sc_onewire, sc->sc_rom);
/*
* Start temperature conversion. The conversion takes up to 750ms.
* After sending the command, the data line must be held high for
* at least 750ms to provide power during the conversion process.
* As such, no other activity may take place on the 1-Wire bus for
* at least this period.
*/
onewire_write_byte(sc->sc_onewire, DS1920_CMD_CONVERT);
tsleep(sc, PRIBIO, "owtemp", hz);
if (onewire_reset(sc->sc_onewire) != 0)
goto done;
onewire_matchrom(sc->sc_onewire, sc->sc_rom);
/*
* The result of the temperature measurement is placed in the
* first two bytes of the scratchpad.
*/
onewire_write_byte(sc->sc_onewire, DS1920_CMD_READ_SCRATCHPAD);
onewire_read_block(sc->sc_onewire, data, 9);
if (onewire_crc(data, 8) == data[DS1920_SP_CRC]) {
temp = data[DS1920_SP_TEMP_MSB] << 8 |
data[DS1920_SP_TEMP_LSB];
if (ONEWIRE_ROM_FAMILY(sc->sc_rom) == ONEWIRE_FAMILY_DS18B20) {
/*
* DS18B20 decoding
* default 12 bit 0.0625 C resolution
*/
val = temp * (1000000 / 16);
} else {
/* DS1920 decoding */
count_perc = data[DS1920_SP_COUNT_PERC];
count_remain = data[DS1920_SP_COUNT_REMAIN];
if (count_perc != 0) {
/* High resolution algorithm */
temp &= ~0x0001;
val = temp * 500000 - 250000 +
((count_perc - count_remain) * 1000000) /
count_perc;
} else {
val = temp * 500000;
}
}
sc->sc_sensor.value = 273150000 + val;
}
done:
onewire_unlock(sc->sc_onewire);
rw_exit_write(&sc->sc_lock);
}
|
