[PATCH v3 0/5] hwmon: Add support for Amphenol ChipCap 2

[Javier Carrasco <javier.carrasco.cruz@gmail.com>]

This series adds support and documentation for the Amphenol ChipCap 2
humidity and temperature sensor in its digital version.

This I2C device provides 14-bit humidity and temperature measurements as
well as low (minimum) and high (maximum) humidity alarms. A ready signal
is also available to reduce delays while fetching data.

The proposed driver implements the logic to perform measurements with
and without the ready signal, EEPROM configuration and alarm signaling.

The features this driver does not support (I2C address and command
window length modification) have been documented in the "Known Issues"
section.

The complete supported functionality has been tested with a CC2D33S
sensor (a 'sleep' device) connected to a Raspberry Pi Zero 2 w.
Different device tree node definitions (with and without regulator,
ready and/or alarm signals) have been positively tested.

The non-sleep measurement mechanism has been inferred from the first
measurement, which is carried out automatically and it is common for all
part numbers. Any testing or improvements with a non-sleep device is
more than welcome.

The tests have also covered the properties added to the hwmon core to
account for minimum and maximum humidity alarms.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
Changes in v3:
- ABI: sysfs-class-hwmon: documented humidity min/max alarms.
- General: reorder patches (bindings first to remove checkpatch
  warnings).
- General: remove part number wildcards and use real part numbers.
- chipcap2.c: improve error path in probe function.
- chipcap2.c: fix error handling if regulator could not be registered.
- chipcap2.c: use absolute values for hysteresis (for both ABI
  compatibility and simplicity).
- chipcap2.c: minor code-style fixes and variable renaming.
- Link to v2: https://lore.kernel.org/r/20231020-topic-chipcap2-v2-0-f5c325966fdb@gmail.com

Changes in v2:
- vendor-prefixes: full company name in the vendor description (Krzystof
  Kozlowski)
- chipcap2.c: proper i2c_device_id table, coding style fixes, cleaner
  error path in the probe function (Krzystof Kozlowski)
- dt-bindings: per-item description and lowercase names (Krzystof
  Kozlowski)
- MAINTAINERS: fix manufacturer name (Krzystof Kozlowski)
- Link to v1: https://lore.kernel.org/r/20231020-topic-chipcap2-v1-0-087e21d4b1ed@gmail.com

---
Javier Carrasco (5):
      dt-bindings: vendor-prefixes: add Amphenol
      hwmon: (core) Add support for humidity min/max alarm
      ABI: sysfs-class-hwmon: add descriptions for humidity min/max alarms
      dt-bindings: hwmon: Add Amphenol ChipCap 2
      hwmon: Add support for Amphenol ChipCap 2

 Documentation/ABI/testing/sysfs-class-hwmon        |   18 +
 .../bindings/hwmon/amphenol,chipcap2.yaml          |   74 ++
 .../devicetree/bindings/vendor-prefixes.yaml       |    2 +
 Documentation/hwmon/chipcap2.rst                   |   73 ++
 Documentation/hwmon/index.rst                      |    1 +
 MAINTAINERS                                        |    8 +
 drivers/hwmon/Kconfig                              |   10 +
 drivers/hwmon/Makefile                             |    1 +
 drivers/hwmon/chipcap2.c                           | 1040 ++++++++++++++++++++
 drivers/hwmon/hwmon.c                              |    2 +
 include/linux/hwmon.h                              |    4 +
 11 files changed, 1233 insertions(+)
---
base-commit: 33cc938e65a98f1d29d0a18403dbbee050dcad9a
change-id: 20231020-topic-chipcap2-e2d8985430c2

Best regards,
-- 
Javier Carrasco <javier.carrasco.cruz@gmail.com>