[RFC PATCH 0/5] Add NVMEM driver for i.MX93 OTP access through ELE

[Arnd Bergmann]

On Wed, Apr 16, 2025, at 16:26, Frieder Schrempf wrote:

> Therefore I implemented a simple driver that uses the ELE S400 API only, as the
> FSB access (1) doesn't provide any benefits except for that it doesn't depend
> on the ELE firmware being available. This is used by us downstream.
>
> For the upstream solution I would like to have some feedback on how to move
> on:
>
> 1. switch imx-ocotp-ele.c to use ELE API exclusively
>    -> this will create a hard dependency on the ELE firmware/driver 
> being available

Could this cause problems for real-time Linux users? Usually going
through a firmware driver adds more latency than doing the thing
from Linux directly, and the firmware is usually not preemptable.

In particular, programming a one-time fuse is likely a slow
operation in hardware, so it may still be necessary to support
both methods if there are users that need to update the fuses
on real-time systems.

     Arnd