diff options
| author | andreast <andreast@FreeBSD.org> | 2012-08-19 19:31:36 +0000 |
|---|---|---|
| committer | andreast <andreast@FreeBSD.org> | 2012-08-19 19:31:36 +0000 |
| commit | ef016efdbc8371041fd053eb74d109c086602e04 (patch) | |
| tree | 59251fce27e1047c27fed56eb0203fc47acd1247 | |
| parent | 7f10a4b817085256cded571619442708e0eeb512 (diff) | |
| download | FreeBSD-src-ef016efdbc8371041fd053eb74d109c086602e04.zip FreeBSD-src-ef016efdbc8371041fd053eb74d109c086602e04.tar.gz | |
Do the ADC init only at startup and not during every sensor read call.
This reduces the number of interrupts.
| -rw-r--r-- | sys/dev/iicbus/ad7417.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/sys/dev/iicbus/ad7417.c b/sys/dev/iicbus/ad7417.c index acd2d89..ac84ffe 100644 --- a/sys/dev/iicbus/ad7417.c +++ b/sys/dev/iicbus/ad7417.c @@ -104,6 +104,7 @@ struct ad7417_softc { uint32_t sc_addr; struct ad7417_sensor *sc_sensors; int sc_nsensors; + int init_done; }; static device_method_t ad7417_methods[] = { /* Device interface */ @@ -247,6 +248,9 @@ ad7417_init_adc(device_t dev, uint32_t addr) { uint8_t buf; int err; + struct ad7417_softc *sc; + + sc = device_get_softc(dev); adc741x_config = 0; /* Clear Config2 */ @@ -267,6 +271,8 @@ ad7417_init_adc(device_t dev, uint32_t addr) if (err < 0) return (-1); + sc->init_done = 1; + return (0); } @@ -430,10 +436,10 @@ ad7417_attach(device_t dev) if (sc->sc_sensors[i].type == ADC7417_TEMP_SENSOR) { unit = "temp"; - desc = "Sensor temp in C"; + desc = "sensor unit (C)"; } else { unit = "volt"; - desc = "Sensor Volt in V"; + desc = "sensor unit (mV)"; } /* I use i to pass the sensor id. */ SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(oid), OID_AUTO, @@ -584,9 +590,10 @@ ad7417_sensor_read(struct ad7417_sensor *sens) sc = device_get_softc(sens->dev); - /* Init the ADC. */ - if (ad7417_init_adc(sc->sc_dev, sc->sc_addr) < 0) - return (-1); + /* Init the ADC if not already done.*/ + if (!sc->init_done) + if (ad7417_init_adc(sc->sc_dev, sc->sc_addr) < 0) + return (-1); if (sens->type == ADC7417_TEMP_SENSOR) { if (ad7417_get_temp(sc->sc_dev, sc->sc_addr, &temp) < 0) |
