mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-02 08:16:41 +07:00
47 lines
1.4 KiB
Plaintext
47 lines
1.4 KiB
Plaintext
|
Kernel driver htu21
|
||
|
|
===================
|
||
|
|
|
||
|
|
Supported chips:
|
||
|
|
* Measurement Specialties HTU21D
|
||
|
|
Prefix: 'htu21'
|
||
|
|
Addresses scanned: none
|
||
|
|
Datasheet: Publicly available at the Measurement Specialties website
|
||
|
|
http://www.meas-spec.com/downloads/HTU21D.pdf
|
||
|
|
|
||
|
|
|
||
|
|
Author:
|
||
|
|
William Markezana <william.markezana@meas-spec.com>
|
||
|
|
|
||
|
|
Description
|
||
|
|
-----------
|
||
|
|
|
||
|
|
The HTU21D is a humidity and temperature sensor in a DFN package of
|
||
|
|
only 3 x 3 mm footprint and 0.9 mm height.
|
||
|
|
|
||
|
|
The devices communicate with the I2C protocol. All sensors are set to the
|
||
|
|
same I2C address 0x40, so an entry with I2C_BOARD_INFO("htu21", 0x40) can
|
||
|
|
be used in the board setup code.
|
||
|
|
|
||
|
|
This driver does not auto-detect devices. You will have to instantiate the
|
||
|
|
devices explicitly. Please see Documentation/i2c/instantiating-devices
|
||
|
|
for details.
|
||
|
|
|
||
|
|
sysfs-Interface
|
||
|
|
---------------
|
||
|
|
|
||
|
|
temp1_input - temperature input
|
||
|
|
humidity1_input - humidity input
|
||
|
|
|
||
|
|
Notes
|
||
|
|
-----
|
||
|
|
|
||
|
|
The driver uses the default resolution settings of 12 bit for humidity and 14
|
||
|
|
bit for temperature, which results in typical measurement times of 11 ms for
|
||
|
|
humidity and 44 ms for temperature. To keep self heating below 0.1 degree
|
||
|
|
Celsius, the device should not be active for more than 10% of the time. For
|
||
|
|
this reason, the driver performs no more than two measurements per second and
|
||
|
|
reports cached information if polled more frequently.
|
||
|
|
|
||
|
|
Different resolutions, the on-chip heater, using the CRC checksum and reading
|
||
|
|
the serial number are not supported yet.
|