Readme file for the Si7005, Si70xx and Si7034 device drivers for Linux
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The Si7005, Si7006, Si7013, Si7015, Si7020, Si7021 and Si7034 are humidity and 
temperature sensor ICs from Silicon Laboratories.  These sensor ICs have an I2C 
interface and have a slave address of 0x40, 0x41 or 0x70.  The Si70xx device 
driver is for the Si7006, Si7013, Si7020 and Si7021 sensor ICs.  The Si7005 device
driver is for the Si7005 and Si7015 sensor ICs.  The Si7034 device driver is 
for the Si7034 sensor IC.

These device drivers were developed on Linux version 3.0.8.  However,
it should run on any Linux version 2.6.22 and after.  The device driver
is written to fit in with the Linux hardware monitoring architecture
(hwmon).  This architecture is defined and maintained by the lm-sensors
project (lm-sensors.org).  The driver was developed using lm-sensors
version 3.3.2.  However, the driver should work with lm-sensors version
3.0.0 and after.

The device driver source code files "si7005.c", "si70xx.c" and "si7034" should 
be placed in the kernel source code tree in the "drivers/hwmon" directory. 
The device driver documentation files "si7005", "si70xx" and "si7034" should be
placed in the "Documentation/hwmon" directory.  The device drivers
should be added to Makefile and Kconfig in the "drivers/hwmon" directory.

When a device driver is initialized, it registers itself with the I2C
core using the driver name "si7005", "Si70xx" or "Si7034".  You must add code 
to the board initialization file or device tree informing the I2C core that 
there a device on the the I2C bus with slave address 0x40, 0x41 or 0x70, and 
it is handled by the "si7005", "si70xx" or "si7034" device driver.

The device driver creates files in the sysfs file system:

      /sys/bus/i2c/devices/4-0040/temp1_input
      /sys/bus/i2c/devices/4-0040/temp2_input          (Si7013 only)
      /sys/bus/i2c/devices/4-0040/humidity1_input
      /sys/bus/i2c/devices/4-0040/device_id
      
These files can also be accessed through their hwmon path:

      /sys/class/hwmon/hwmon0/device/temp1_input
      /sys/class/hwmon/hwmon0/device/temp2_input       (Si7013 only)
      /sys/class/hwmon/hwmon0/device/humidity1_input
      /sys/class/hwmon/hwmon0/device/device_id

Note: The "4-0040" directory indicates that the sensor IC is located on 
      the fourth I2C bus at slave address 0x40.  This may be different
      on your system.
      
An application can read from these files to get the humidity and temperature
in millidegrees and millipercent (pcm).
      
