Re: [PATCH v2 4/5] arm64: dts: google: Add initial dts for frankel/blazer/mustang

[Linus Walleij]

On Wed, Aug 19, 2026 at 7:03 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:

> I appreciate your suggestion of having a separate node for calibration
> storage. This feels more awkward to me than just giving up and having
> the bootloader hardcode all known device-tree paths that the UFS node
> might be found at. That being said, if everyone says that this would
> be a great solution, I could try prototyping it. The trick would now
> be that the Linux UFS driver would need to be able to find this
> calibration data, so the Linux UFS driver would either need to be able
> to find it at a specific hardcoded device tree path or the Linux UFS
> driver would need to search the device tree for a specific
> ufs-calibration compatible string.

Can't you just put the calibration data as a custom property inside
the UFS DT node? Just a long byte array or whatever it is.
The driver would certainly know where to find it that way.
I don't know who or how it has to be put there during manufacturing
or inserted by the boot loader into the node from wherever
manufacturing stores it though. (Assuming it's some calibration
added at manufacturing, I don't exactly know what it is...)
If the actual storage place is in something the OS can read
then we could probably use the nvmem to fetch it live?

The calibration business and what it is and where it is stored
evades me a bit...

Yours,
Linus Walleij