From 3af350929e752fe72f0457033d448bff9aac695a Mon Sep 17 00:00:00 2001 From: Javier Carrasco Date: Tue, 30 Jan 2024 22:06:48 +0100 Subject: hwmon: Add support for Amphenol ChipCap 2 The Amphenol ChipCap 2 is a capacitive polymer humidity and temperature sensor with an integrated EEPROM and minimum/maximum humidity alarms. All device variants offer an I2C interface and depending on the part number, two different output modes: - CC2D: digital output - CC2A: analog (PDM) output This driver adds support for the digital variant (CC2D part numbers), which includes the following part numbers: - non-sleep measurement mode (CC2D23, CC2D25, CC2D33, CC2D35) - sleep measurement mode (CC2D23S, CC2D25S, CC2D33S, CC2D35S) The Chipcap 2 EEPROM can be accessed to configure a series of parameters like the minimum/maximum humidity alarm threshold and hysteresis. The EEPROM is only accessible in the command window after a power-on reset. The default window lasts 10 ms if no Start_CM command is sent. After the command window is finished (either after the mentioned timeout of after a Start_NOM command is sent), the device enters the normal operation mode and makes a first measurement automatically. Unfortunately, the device does not provide any hardware or software reset and therefore the driver must trigger power cycles to enter the command mode. A dedicated, external regulator is required for that. This driver keeps the device off until a measurement or access to the EEPROM is required, making use of the first automatic measurement to avoid different code paths for sleep and non-sleep devices. The minimum and maximum humidity alarms are configured with two registers per alarm: one stores the alarm threshold and the other one keeps the value that turns off the alarm. The alarm signals are only updated when a measurement is carried out. Signed-off-by: Javier Carrasco Link: https://lore.kernel.org/r/20240130-topic-chipcap2-v6-5-260bea05cf9b@gmail.com Signed-off-by: Guenter Roeck --- Documentation/hwmon/index.rst | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/hwmon/index.rst') diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 9ac087dd3e78..0d12254c0f9e 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -51,6 +51,7 @@ Hardware Monitoring Kernel Drivers bel-pfe bpa-rs600 bt1-pvt + chipcap2 coretemp corsair-cpro corsair-psu -- cgit