Re: [PATCH v4 0/4] block: preparations for NVMEM provider

[Jens Axboe <axboe@kernel.dk>]

On 6/27/24 2:49 PM, 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.
> 
> Typically the NVMEM framework is used to have kernel drivers read and
> use binary data from EEPROMs, efuses, flash memory (MTD), ...
> 
> Using references to NVMEM bits in Device Tree allows the kernel to
> access and apply e.g. the Ethernet MAC address, which can be a requirement
> for userland to come up (e.g. for nfsroot).
> 
> The goal of this series is to prepare the block subsystem to allow for
> the implementation of an NVMEM provider similar to other types of
> non-volatile storage, so the same approach already used for EEPROMs, MTD
> (raw flashes) and UBI-managed NAND can also be used for devices storing
> those bits on an eMMC.
> 
> Define a device tree schema for block devices and partitions on them,
> which (similar to how it now works also for UBI volumes) can be matched
> by one or more properties.
> 
> Also add a simple notification API for other subsystems to be notified
> about additions and removals of block devices, which is going to be used
> by the block-backed NVMEM provider.
> 
> Overall, this enables uniform handling across practially all flash
> storage types used for this purpose (MTD, UBI, and soon also MMC or and
> in future maybe also other block devices).

2-4 look fine to me now, but I don't know anything about the device
bindings so someone qualified should review that before it gets queued
up.
 
-- 
Jens Axboe