Re: [PATCH V2 1/2] nvmem: core: refactor .cell_post_process() CB arguments

From: Michael Walle
Date: Mon Nov 28 2022 - 02:35:30 EST


Am 2022-11-28 07:59, schrieb Rafał Miłecki:
From: Rafał Miłecki <rafal@xxxxxxxxxx>

Pass whole NVMEM cell struct and length pointer as arguments to callback
functions.

This allows:

1. Cells content to be modified based on more info
Some cells (identified by their names) contain specific data that
needs further processing. This can be e.g. MAC address stored in an
ASCII format. NVMEM consumers expect MAC to be read in a binary form.
More complex cells may be additionally described in DT. This change
allows also accessing relevant DT nodes and reading extra info.

2. Adjusting data length
If cell processing results in reformatting it, it's required to
adjust length. This again applies e.g. to the MAC format change from
ASCII to the byte-based.

Later on we may consider more cleanups & features like:
1. Dropping "const char *id" and just using NVMEM cell name
2. Adding extra argument for cells providing multiple values

Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
---
This solution conflicts with 1 part of Michael's work:
[PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@xxxxxxxx/

Instead of:
1. Adding NVMEM cell-level post_process callback
2. Adding callback (.fixup_cell_info()) for setting callbacks
3. Dropping NVMEM device-level post_process callback
I decided to refactor existing callback.

Michael's work on adding #nvmem-cell-cells should be possible to easily
rebase on top of those changes.

As yours should be easily added on top of my series. I've showed that
providing a global post process hook is bad because that way you need
to have *all* cells of your device read-only.

-michael