From cc15c7ebb424e45ba2c5ceecbe52d025219ee970 Mon Sep 17 00:00:00 2001 From: Vivien Didelot Date: Tue, 12 Apr 2011 15:34:38 -0400 Subject: hwmon: (sht15) add support for the status register * Add support for: - Heater. - End of battery notice. - Ability not to reload from OTP. - Low resolution (12bit temp, 8bit humidity). * Add an utility function to read individual bytes from the device. Signed-off-by: Vivien Didelot Acked-by: Jonathan Cameron Signed-off-by: Guenter Roeck --- Documentation/hwmon/sht15 | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'Documentation/hwmon') diff --git a/Documentation/hwmon/sht15 b/Documentation/hwmon/sht15 index 2919c516fdbc..d1939b25eb16 100644 --- a/Documentation/hwmon/sht15 +++ b/Documentation/hwmon/sht15 @@ -4,6 +4,7 @@ Kernel driver sht15 Authors: * Wouter Horre * Jonathan Cameron + * Vivien Didelot Supported chips: * Sensirion SHT10 @@ -30,13 +31,37 @@ Description The SHT10, SHT11, SHT15, SHT71, and SHT75 are humidity and temperature sensors. -The devices communicate using two GPIO lines and use the default -resolution settings of 14 bits for temperature and 12 bits for humidity. +The devices communicate using two GPIO lines. + +Supported resolutions for the measurements are 14 bits for temperature and 12 +bits for humidity, or 12 bits for temperature and 8 bits for humidity. + +The humidity calibration coefficients are programmed into an OTP memory on the +chip. These coefficients are used to internally calibrate the signals from the +sensors. Disabling the reload of those coefficients allows saving 10ms for each +measurement and decrease power consumption, while loosing on precision. + +Some options may be set directly in the sht15_platform_data structure +or via sysfs attributes. Note: The regulator supply name is set to "vcc". +Platform data +------------- + +* no_otp_reload: + flag to indicate not to reload from OTP (default to false). +* low_resolution: + flag to indicate the temp/humidity resolution to use (default to false). + Sysfs interface --------------- * temp1_input: temperature input * humidity1_input: humidity input +* heater_enable: write 1 in this attribute to enable the on-chip heater, + 0 to disable it. Be careful not to enable the heater + for too long. +* temp1_fault: if 1, this means that the voltage is low (below 2.47V) and + measurement may be invalid. +* humidity1_fault: same as temp1_fault. -- cgit v1.2.3-59-g8ed1b