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authorVivien Didelot <vivien.didelot@savoirfairelinux.com>2011-04-12 15:34:38 -0400
committerGuenter Roeck <guenter.roeck@ericsson.com>2011-05-19 08:19:35 -0700
commitcc15c7ebb424e45ba2c5ceecbe52d025219ee970 (patch)
treeb5f752332d07352bc3d38381c554a3d71beeb588 /Documentation/hwmon/sht15
parent181148ae68799f5b17f09b418b276f56e9179e99 (diff)
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 <vivien.didelot@savoirfairelinux.com> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Diffstat (limited to 'Documentation/hwmon/sht15')
-rw-r--r--Documentation/hwmon/sht1529
1 files changed, 27 insertions, 2 deletions
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 <vivien.didelot@savoirfairelinux.com>
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.