Re: [PATCH v2 1/6] dt-bindings: hwmon: add binding for adi,adt7470
Luiz Angelo Daros de Luca <[email protected]> Mon, 20 Jul 2026 23:12:49 -0300
| Newsgroups | org.kernel.vger.linux-pwm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-hwmon,org.kernel.vger.linux-kernel |
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| Message-ID | <CAJq09z6qQnKXgBnQKCey4u47hsJTjpYXPDvDZj76sXHZuj2emQ@mail.gmail.com> |
> From the datasheet: "The ADT74701 controller is a multichannel > temperature sensor and PWM fan controller and fan speed monitor". > > It is a fan controller which happens to use pwm signals to control > fan speeds. It is not a PWM controller, and its pwm outputs are not > intended to be used for anything but controlling fan speeds. > > Technically it is _possible_ to use the pwm outputs to control > something else. But that does not mean that chip is a pwm controller. > It is still a fan controller. I don't mind modeling outputs as > non-fan-control pwm channels if that is what they are used for, > but that must be clearly distinguished in both the driver code > and the bindings. Hi Guenter, You are absolutely right. The datasheet explicitly defines the ADT7470 as a "PWM fan controller and fan speed monitor," and its internal features (like tachometer inputs and thermal acoustic enhancement) are heavily tailored for fan control. I agree that calling it a generic PWM controller is technically inaccurate. I will revert the change and describe it as a PWM Fan Controller, provided everyone is on board with that. Initially, I modeled the driver purely as a cooling device. However, following Sashiko-dev's suggestion in a previous review, I converted it to expose PWM channels so it could be used with the generic pwm-fan driver (which indeed makes the code cleaner). My primary experience is with DSA switches, so hwmon is a new area for me. Whatever you and the DT maintainers agree on, I will gladly adjust for v3. Best regards, Luiz