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1.. SPDX-License-Identifier: GPL-2.0-or-later2 3Kernel driver ChipCap24======================5 6Supported chips:7 8 * Amphenol CC2D23, CC2D23S, CC2D25, CC2D25S, CC2D33, CC2D33S, CC2D35, CC2D35S9 10 Prefix: 'chipcap2'11 12 Addresses scanned: -13 14 Datasheet: https://www.amphenol-sensors.com/en/telaire/humidity/527-humidity-sensors/3095-chipcap-215 16Author:17 18 - Javier Carrasco <javier.carrasco.cruz@gmail.com>19 20Description21-----------22 23This driver implements support for the Amphenol ChipCap 2, a humidity and24temperature chip family. Temperature is measured in milli degrees celsius,25relative humidity is expressed as a per cent mille. The measurement ranges26are the following:27 28 - Relative humidity: 0 to 100000 pcm (14-bit resolution)29 - Temperature: -40000 to +125000 m°C (14-bit resolution)30 31The device communicates with the I2C protocol and uses the I2C address 0x2832by default.33 34Depending on the hardware configuration, up to two humidity alarms to control35minimum and maximum values are provided. Their thresholds and hystersis can be36configured via sysfs.37 38Thresholds and hysteris must be provided as a per cent mille. These values39might be truncated to match the 14-bit device resolution (6.1 pcm/LSB)40 41Known Issues42------------43 44The driver does not support I2C address and command window length modification.45 46sysfs-Interface47---------------48 49The following list includes the sysfs attributes that the driver always provides,50their permissions and a short description:51 52=============================== ======= ========================================53Name Perm Description54=============================== ======= ========================================55temp1_input: RO temperature input56humidity1_input: RO humidity input57=============================== ======= ========================================58 59The following list includes the sysfs attributes that the driver may provide60depending on the hardware configuration:61 62=============================== ======= ========================================63Name Perm Description64=============================== ======= ========================================65humidity1_min: RW humidity low limit. Measurements under66 this limit trigger a humidity low alarm67humidity1_max: RW humidity high limit. Measurements above68 this limit trigger a humidity high alarm69humidity1_min_hyst: RW humidity low hystersis70humidity1_max_hyst: RW humidity high hystersis71humidity1_min_alarm: RO humidity low alarm indicator72humidity1_max_alarm: RO humidity high alarm indicator73=============================== ======= ========================================74