Commit a6bffb69 authored by Harald Geyer's avatar Harald Geyer Committed by Jonathan Cameron

iio: dht11: Improve detection of sensor type

The old code was based on a DHT11 datasheet which specifies a measurement
range of 20%-90% RH. Turns out the sensor actually reports values outside
this range, so we should support it as far as possible.
Reported-by: default avatarEdward Attfield <edward@attfield.ca>
Signed-off-by: default avatarHarald Geyer <harald@ccbib.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 7fe2241c
...@@ -159,7 +159,7 @@ static int dht11_decode(struct dht11 *dht11, int offset) ...@@ -159,7 +159,7 @@ static int dht11_decode(struct dht11 *dht11, int offset)
} }
dht11->timestamp = ktime_get_boot_ns(); dht11->timestamp = ktime_get_boot_ns();
if (hum_int < 20) { /* DHT22 */ if (hum_int < 4) { /* DHT22: 100000 = (3*256+232)*100 */
dht11->temperature = (((temp_int & 0x7f) << 8) + temp_dec) * dht11->temperature = (((temp_int & 0x7f) << 8) + temp_dec) *
((temp_int & 0x80) ? -100 : 100); ((temp_int & 0x80) ? -100 : 100);
dht11->humidity = ((hum_int << 8) + hum_dec) * 100; dht11->humidity = ((hum_int << 8) + hum_dec) * 100;
......
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