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1Kernel driver sht152===================3 4Authors:5 6 * Wouter Horre7 * Jonathan Cameron8 * Vivien Didelot <vivien.didelot@savoirfairelinux.com>9 * Jerome Oufella <jerome.oufella@savoirfairelinux.com>10 11Supported chips:12 13 * Sensirion SHT1014 15 Prefix: 'sht10'16 17 * Sensirion SHT1118 19 Prefix: 'sht11'20 21 * Sensirion SHT1522 23 Prefix: 'sht15'24 25 * Sensirion SHT7126 27 Prefix: 'sht71'28 29 * Sensirion SHT7530 31 Prefix: 'sht75'32 33Datasheet: Publicly available at the Sensirion website34 35 http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf36 37Description38-----------39 40The SHT10, SHT11, SHT15, SHT71, and SHT75 are humidity and temperature41sensors.42 43The devices communicate using two GPIO lines.44 45Supported resolutions for the measurements are 14 bits for temperature and 1246bits for humidity, or 12 bits for temperature and 8 bits for humidity.47 48The humidity calibration coefficients are programmed into an OTP memory on the49chip. These coefficients are used to internally calibrate the signals from the50sensors. Disabling the reload of those coefficients allows saving 10ms for each51measurement and decrease power consumption, while losing on precision.52 53Some options may be set via sysfs attributes.54 55Notes:56 * The regulator supply name is set to "vcc".57 * If a CRC validation fails, a soft reset command is sent, which resets58 status register to its hardware default value, but the driver will try to59 restore the previous device configuration.60 61Platform data62-------------63 64* checksum:65 set it to true to enable CRC validation of the readings (default to false).66* no_otp_reload:67 flag to indicate not to reload from OTP (default to false).68* low_resolution:69 flag to indicate the temp/humidity resolution to use (default to false).70 71Sysfs interface72---------------73 74================== ==========================================================75temp1_input temperature input76humidity1_input humidity input77heater_enable write 1 in this attribute to enable the on-chip heater,78 0 to disable it. Be careful not to enable the heater79 for too long.80temp1_fault if 1, this means that the voltage is low (below 2.47V) and81 measurement may be invalid.82humidity1_fault same as temp1_fault.83================== ==========================================================84