svn commit: r355531 - head/sys/dev/gpio
Ian Lepore
ian at FreeBSD.org
Sun Dec 8 20:13:43 UTC 2019
Author: ian
Date: Sun Dec 8 20:13:42 2019
New Revision: 355531
URL: https://svnweb.freebsd.org/changeset/base/355531
Log:
Several small fixes for the gpioths (temp/humidity sensor) driver.
At the end of a read cycle, set the gpio pin to INPUT rather than OUTPUT.
The state of the single-wire "bus" when idle should be high; setting the
pin to input allows the external pullup to pull the line high. Setting it
to output (and leaving it driving low) was leading a good read cycle followed
by one that would fail, and it just continued like that forever, effectively
reading the sensor once every 10 seconds instead of 5.
In the attach function, do an initial read from the device before registering
the sysctls for accessing the last-read values, to prevent reading spurious
values for the first 5 seconds after the driver attaches.
Do a callout_drain() in the detach function to prevent crashes after
unloading the module.
Modified:
head/sys/dev/gpio/gpioths.c
Modified: head/sys/dev/gpio/gpioths.c
==============================================================================
--- head/sys/dev/gpio/gpioths.c Sun Dec 8 16:59:36 2019 (r355530)
+++ head/sys/dev/gpio/gpioths.c Sun Dec 8 20:13:42 2019 (r355531)
@@ -198,9 +198,9 @@ gpioths_dht_readbytes(device_t bus, device_t dev)
}
}
- err = GPIOBUS_PIN_SETFLAGS(bus, dev, 0, GPIO_PIN_OUTPUT);
+ err = GPIOBUS_PIN_SETFLAGS(bus, dev, 0, GPIO_PIN_INPUT);
if (err != 0) {
- device_printf(dev, "err(FINAL_SETFLAGS, OUT) = %d\n", err);
+ device_printf(dev, "err(FINAL_SETFLAGS, IN) = %d\n", err);
goto error;
}
DELAY(1);
@@ -331,8 +331,11 @@ gpioths_attach(device_t dev)
sc->dev = dev;
- callout_init(&sc->callout, 1);
- callout_reset(&sc->callout, GPIOTHS_POLLTIME * hz, gpioths_poll, dev);
+ /*
+ * Do an initial read so we have correct values for reporting before
+ * registering the sysctls that can access those values.
+ */
+ gpioths_dht_readbytes(device_get_parent(dev), dev);
sc->temp_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"temperature", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
@@ -346,12 +349,20 @@ gpioths_attach(device_t dev)
"fails", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
gpioths_fails_sysctl, "I", "fails since last successful read");
+ callout_init(&sc->callout, 1);
+ callout_reset(&sc->callout, GPIOTHS_POLLTIME * hz, gpioths_poll, dev);
+
return (0);
}
static int
gpioths_detach(device_t dev)
{
+ struct gpioths_softc *sc;
+
+ sc = device_get_softc(dev);
+
+ callout_drain(&sc->callout);
return (0);
}
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