diff options
| author | Todd T. Fries <todd@cvs.openbsd.org> | 2008-12-26 18:17:26 +0000 |
|---|---|---|
| committer | Todd T. Fries <todd@cvs.openbsd.org> | 2008-12-26 18:17:26 +0000 |
| commit | bf3b6f2384dfb5783abe569c9796e049014076e7 (patch) | |
| tree | 2d545ca2527563f032e8a60856ec5027af70244f /sys/dev/onewire/owtemp.c | |
| parent | a05cf1cf173171bb9fe2f11155e0074f3afdd327 (diff) | |
implement support for another temperature sensor, DS18B20
from David Fries david(at)fries(dot)net
ok grange@
Diffstat (limited to 'sys/dev/onewire/owtemp.c')
| -rw-r--r-- | sys/dev/onewire/owtemp.c | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/sys/dev/onewire/owtemp.c b/sys/dev/onewire/owtemp.c index 204ed1e93f8..0016c9393db 100644 --- a/sys/dev/onewire/owtemp.c +++ b/sys/dev/onewire/owtemp.c @@ -1,4 +1,4 @@ -/* $OpenBSD: owtemp.c,v 1.10 2008/10/25 00:27:09 deraadt Exp $ */ +/* $OpenBSD: owtemp.c,v 1.11 2008/12/26 18:17:25 todd Exp $ */ /* * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org> @@ -41,6 +41,7 @@ #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 @@ -77,7 +78,8 @@ struct cfdriver owtemp_cd = { }; static const struct onewire_matchfam owtemp_fams[] = { - { ONEWIRE_FAMILY_DS1920 } + { ONEWIRE_FAMILY_DS1920 }, + { ONEWIRE_FAMILY_DS18B20 } }; int @@ -172,17 +174,26 @@ owtemp_update(void *arg) if (onewire_crc(data, 8) == data[DS1920_SP_CRC]) { temp = data[DS1920_SP_TEMP_MSB] << 8 | data[DS1920_SP_TEMP_LSB]; - 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; + if (ONEWIRE_ROM_FAMILY(sc->sc_rom) == ONEWIRE_FAMILY_DS18B20) { + /* + * DS18B20 decoding + * default 12 bit 0.0625 C resolution + */ + val = temp * (1000000 / 16); } else { - val = temp * 500000; + /* 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; } |