Re: [PATCH 0/4] hwmon: Add WITRN USB tester driver

Guenter Roeck
2026-03-27T00:05:15Z

On 3/26/26 12:19, Rong Zhang wrote:
> WITRN produces a series of devices to monitor power characteristics of
> USB connections and display those on a on-device display. Most of them
> contain an additional port which exposes the measurements via USB HID.
>
> These devices report sensor values in IEEE-754 float (binary32) format.
> The driver must perform floating-point number to integer conversions to
> provide hwmon channels. Meanwhile, they also report accumulative float
> values, and simple division or multiplication turns them into useful
> hwmon channels.
>
> Patch 1 adds label support for 64-bit energy attributes, as the driver
> needs it.
>
> Patch 2 adds a helper module for floating-point to integer conversions,
> so that the conversion, multification and division methods can be used
> in this driver as well as other drivers (I am also working on another
> USB tester driver that needs it).
>
> Patch 3 adds a barebone HID driver for WITRN K2.
>
> Patch 4 adds hwmon channels and attributes to the driver.
>
> Signed-off-by: Rong Zhang <i@rong.moe>
> ---
> Rong Zhang (4):
> hwmon: Add label support for 64-bit energy attributes
> hwmon: New helper module for floating-point to integer conversions

Nack. This is not a hwmon problem and should reside in a driver or in lib/
(if it is needed by multiple drivers).

> hwmon: Add barebone HID driver for WITRN

Nack. This is the wrong place for such a driver. It should reside somewhere
in drivers/usb, or maybe in drivers/misc/.

> hwmon: (witrn) Add monitoring support

This should be implemented as auxiliary driver.

Sashiko has a lot of feedback that you might want to address before
resubmitting.

https://sashiko.dev/#/patchset/20260327-b4-hwmon-witrn-v1-0-8d2f1896c045%40rong.moe

Thanks,
Guenter

>
> Documentation/hwmon/index.rst | 1 +
> Documentation/hwmon/witrn.rst | 53 ++++
> MAINTAINERS | 7 +
> drivers/hwmon/Kconfig | 14 +
> drivers/hwmon/Makefile | 2 +
> drivers/hwmon/hwmon-fp.c | 262 ++++++++++++++++
> drivers/hwmon/hwmon-fp.h | 212 +++++++++++++
> drivers/hwmon/hwmon.c | 1 +
> drivers/hwmon/witrn.c | 691 ++++++++++++++++++++++++++++++++++++++++++
> 9 files changed, 1243 insertions(+)
> ---
> base-commit: 0138af2472dfdef0d56fc4697416eaa0ff2589bd
> change-id: 20260327-b4-hwmon-witrn-a629b9040250
>
> Thanks,
> Rong
>