An sht3x sensor include limits register which contains temperature
and humidity limit values. After a reset, pre-defined values are loaded
into that register. During the probe function, the driver reads the
limits register. However, if the reads are made too early, and the bus
is clocked at high frequencies (e.g. 100 kHz or more), the loading could be
not completed and the sensor returns a NACK which causes the probe to fail.
A delay of at least 500 us before the first read solves this issue.
Signed-off-by: Emiliano Ingrassia <ingrassia@epigenesys.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Handling the wraparound requires the data->last_update to be set to an
initial jiffies value. Otherwise on 32-bit systems you will not be able
to request a reading till the 5 minute jiffies rollover happens.
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: David Frey <david.frey@sensirion.com>
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Fixes: 7c84f7f80d ("hwmon: add support for Sensirion SHT3x sensors")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The enables control of the SHT31 sensors heating element that can turned
on to remove excess humidity.
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: David Frey <david.frey@sensirion.com>
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This driver implements support for the Sensirion SHT3x-DIS chip,
a humidity and temperature sensor. Temperature is measured
in degrees celsius, relative humidity is expressed as a percentage.
In the sysfs interface, all values are scaled by 1000,
i.e. the value for 31.5 degrees celsius is 31500.
Signed-off-by: Pascal Sachs <pascal.sachs@sensirion.com>
[groeck: Fixed 'Variable length array is used' gcc warning]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Emiliano Ingrassia