Romulus avsbus-control and vrm-control

Romulus avsbus-control and vrm-control

[Alexander Soldatov]

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  Hi Lei YU,


  There is some question about avsbus-control and vrm-control on the Romulus. There are no public documentation for the IR35221 chips, which are used in the Romulus. Could anyone explain what  avsbus-control and vrm-control i2c command sequences do or give register description for the IR35221, please?


  Regards,

  Alexander Soldatov.

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Re: Romulus avsbus-control and vrm-control

[Lei YU]

Hi Alexander,

The related controls to IR35221 are referenced from meta-witherspoon
and Romulus schematic.
If you need details, possibly contact Nick (ngruend@us.ibm.com) who is
the chief engineer of Romulus.

Thanks!

On Fri, May 17, 2019 at 3:48 PM Alexander Soldatov <a.soldatov@yadro.com> wrote:
>
>   Hi Lei YU,
>
>
>   There is some question about avsbus-control and vrm-control on the Romulus. There are no public documentation for the IR35221 chips, which are used in the Romulus. Could anyone explain what  avsbus-control and vrm-control i2c command sequences do or give register description for the IR35221, please?
>
>
>   Regards,
>
>   Alexander Soldatov.

Re: Romulus avsbus-control and vrm-control

[Joel Stanley]

On Fri, 17 May 2019 at 07:48, Alexander Soldatov <a.soldatov@yadro.com> wrote:
>
>   Hi Lei YU,
>
>
>   There is some question about avsbus-control and vrm-control on the Romulus. There are no public documentation for the IR35221 chips, which are used in the Romulus. Could anyone explain what  avsbus-control and vrm-control i2c command sequences do or give register description for the IR35221, please?

There's an upstream driver for this part that may help:

drivers/hwmon/pmbus/ir35221.c

There was a plan to replace (some?) of the scripts you reference with
the kernel driver. However these parts are powered by the same net as
the CPU, so when the host is powered off the hwmon driver cannot be
used. It would be good to come up with a kernel based solution here.

Cheers,

Joel