[RFC PATCH 0/6] nvmem: add block device NVMEM provider

[Bart Van Assche]

On 7/19/23 15:01, Daniel Golle wrote:
> On embedded devices using an eMMC it is common that one or more (hw/sw)
> partitions on the eMMC are used to store MAC addresses and Wi-Fi
> calibration EEPROM data.
> 
> Implement an NVMEM provider backed by block devices as typically the
> NVMEM framework is used to have kernel drivers read and use binary data
> from EEPROMs, efuses, flash memory (MTD), ...
> 
> In order to be able to reference hardware partitions on an eMMC, add code
> to bind each hardware partition to a specific firmware subnode.
> 
> This series is meant to open the discussion on how exactly the device tree
> schema for block devices and partitions may look like, and even if using
> the block layer to back the NVMEM device is at all the way to go -- to me
> it seemed to be a good solution because it will be reuable e.g. for NVMe.

Is my understanding correct that these devices boot from eMMC and not over
Wi-Fi? If so, why does this calibration data have to be stored on a raw
block device? Why can't this information be loaded from a file on a
filesystem?

Thanks,

Bart.