diff options
| -rw-r--r-- | sys/dev/isa/it.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/sys/dev/isa/it.c b/sys/dev/isa/it.c index 6e181fd4c37..00e17c9b911 100644 --- a/sys/dev/isa/it.c +++ b/sys/dev/isa/it.c @@ -1,4 +1,4 @@ -/* $OpenBSD: it.c,v 1.19 2006/04/10 00:57:54 deraadt Exp $ */ +/* $OpenBSD: it.c,v 1.20 2006/06/24 13:42:45 kettenis Exp $ */ /* * Copyright (c) 2003 Julien Bordet <zejames@greyhats.org> @@ -43,6 +43,16 @@ #define DPRINTF(x) #endif +/* + * IT87-compatible chips can typically measure voltages up to 4.096 V. + * To measure higher voltages the input is attenuated with (external) + * resistors. Negative voltages are measured using a reference + * voltage. So we have to convert the sensor values back to real + * voltages by applying the appropriate resistor factor. + */ +#define RFACT_NONE 10000 +#define RFACT(x, y) (RFACT_NONE * ((x) + (y)) / (y)) + int it_match(struct device *, void *, void *); void it_attach(struct device *, struct device *, void *); u_int8_t it_readreg(struct it_softc *, int); @@ -68,6 +78,18 @@ struct cfdriver it_cd = { NULL, "it", DV_DULL }; +const int it_vrfact[] = { + RFACT_NONE, + RFACT_NONE, + RFACT_NONE, + RFACT(68, 100), + RFACT(30, 10), + RFACT(21, 10), + RFACT(83, 20), + RFACT(68, 100), + RFACT_NONE +}; + int it_match(struct device *parent, void *match, void *aux) { @@ -175,31 +197,22 @@ it_setup_volt(struct it_softc *sc, int start, int n) sc->sensors[start + i].type = SENSOR_VOLTS_DC; } - sc->sensors[start + 0].rfact = 10000; snprintf(sc->sensors[start + 0].desc, sizeof(sc->sensors[0].desc), "VCORE_A"); - sc->sensors[start + 1].rfact = 10000; snprintf(sc->sensors[start + 1].desc, sizeof(sc->sensors[1].desc), "VCORE_B"); - sc->sensors[start + 2].rfact = 10000; snprintf(sc->sensors[start + 2].desc, sizeof(sc->sensors[2].desc), "+3.3V"); - sc->sensors[start + 3].rfact = (int)(( 16.8 / 10) * 10000); snprintf(sc->sensors[start + 3].desc, sizeof(sc->sensors[3].desc), "+5V"); - sc->sensors[start + 4].rfact = (int)(( 40 / 10) * 10000); snprintf(sc->sensors[start + 4].desc, sizeof(sc->sensors[4].desc), "+12V"); - sc->sensors[start + 5].rfact = (int)(( 31.0 / 10) * 10000); snprintf(sc->sensors[start + 5].desc, sizeof(sc->sensors[5].desc), "Unused"); - sc->sensors[start + 6].rfact = (int)(( 103.0 / 20) * 10000); snprintf(sc->sensors[start + 6].desc, sizeof(sc->sensors[6].desc), "-12V"); - sc->sensors[start + 7].rfact = (int)(( 16.8 / 10) * 10000); snprintf(sc->sensors[start + 7].desc, sizeof(sc->sensors[7].desc), "+5VSB"); - sc->sensors[start + 8].rfact = 10000; snprintf(sc->sensors[start + 8].desc, sizeof(sc->sensors[8].desc), "VBAT"); } @@ -252,18 +265,15 @@ it_generic_svolt(struct it_softc *sc, struct sensor *sensors) DPRINTF(("sdata[volt%d] 0x%x\n", i, sdata)); /* voltage returned as (mV >> 4) */ sensors[i].value = (sdata << 4); - /* rfact is (factor * 10^4) */ - sensors[i].value *= sensors[i].rfact; /* these two values are negative and formula is different */ - if (i == 5) - sensors[i].value -= - (int) (21.0 / 10 * IT_VREF * 10000); - if (i == 6) - sensors[i].value -= - (int) (83.0 / 20 * IT_VREF * 10000); + if (i == 5 || i == 6) + sensors[i].value = ((sdata << 4) - IT_VREF); + /* rfact is (factor * 10^4) */ + sensors[i].value *= it_vrfact[i]; /* division by 10 gets us back to uVDC */ sensors[i].value /= 10; - + if (i == 5 || i == 6) + sensors[i].value += IT_VREF * 1000; } } |