Hello, These patches add a hwmon pmbus driver for the integrated fan control module in the Delta AHE-50DC Open19 power shelf. I don't know of a datasheet or any proper documentation for it. It's a PMBus device, but supports a fairly limited set of commands. The ones it does support have deen deduced from a combination of an existing GPL driver in a code release from LinkedIn [0] and some manual experimentation with i2c-tools commands. In addition to some standard PMBus sensors (three temperature readings, four fan speeds, and a vin voltage), it also has a manufacturer-specific fourth temperature reading available, which is supported via a virtual second page (the device itself is not paged, but the driver remaps PMBUS_READ_TEMPERATURE_1 in page 1 to the manufacturer-specific TEMPERATURE_4). Thanks, Zev Weiss Changes since v3 [3]: - fixed header inclusion order - removed spurious select/depends Kconfig lines - added comment explaining PMBUS_NO_CAPABILITY - added command-filtering to read_word_data callback to avoid producing bogus sensor limits - updated commit message Changes since v2 [2]: - converted to pmbus driver Changes since v1 [1]: - fixed invalid name warning from __hwmon_device_register() [0] https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-kernel/fancontrol-mod/files/fancontrol.c [1] https://lore.kernel.org/linux-hwmon/20211206224419.15736-1-zev@xxxxxxxxxxxxxxxxx/ [2] https://lore.kernel.org/linux-hwmon/20211206230153.16891-1-zev@xxxxxxxxxxxxxxxxx/ [3] https://lore.kernel.org/linux-hwmon/20211207071521.543-1-zev@xxxxxxxxxxxxxxxxx/ Zev Weiss (2): hwmon: (pmbus) Add Delta AHE-50DC fan control module driver dt-bindings: add Delta AHE-50DC fan control module .../devicetree/bindings/trivial-devices.yaml | 2 + MAINTAINERS | 6 + drivers/hwmon/pmbus/Kconfig | 10 ++ drivers/hwmon/pmbus/Makefile | 1 + drivers/hwmon/pmbus/delta-ahe50dc-fan.c | 114 ++++++++++++++++++ 5 files changed, 133 insertions(+) create mode 100644 drivers/hwmon/pmbus/delta-ahe50dc-fan.c -- 2.34.1