Hi Srinivas, michael@xxxxxxxx wrote on Tue, 6 Dec 2022 21:07:19 +0100: > This is now the third attempt to fetch the MAC addresses from the VPD > for the Kontron sl28 boards. Previous discussions can be found here: > https://lore.kernel.org/lkml/20211228142549.1275412-1-michael@xxxxxxxx/ > > > NVMEM cells are typically added by board code or by the devicetree. But > as the cells get more complex, there is (valid) push back from the > devicetree maintainers to not put that handling in the devicetree. > > Therefore, introduce NVMEM layouts. They operate on the NVMEM device and > can add cells during runtime. That way it is possible to add more complex > cells than it is possible right now with the offset/length/bits > description in the device tree. For example, you can have post processing > for individual cells (think of endian swapping, or ethernet offset > handling). > > The imx-ocotp driver is the only user of the global post processing hook, > convert it to nvmem layouts and drop the global post pocessing hook. > > For now, the layouts are selected by the device tree. But the idea is > that also board files or other drivers could set a layout. Although no > code for that exists yet. > > Thanks to Miquel, the device tree bindings are already approved and merged. > > NVMEM layouts as modules? > While possible in principle, it doesn't make any sense because the NVMEM > core can't be compiled as a module. The layouts needs to be available at > probe time. (That is also the reason why they get registered with > subsys_initcall().) So if the NVMEM core would be a module, the layouts > could be modules, too. I believe this series still applies even though -rc1 (and -rc2) are out now, may we know if you consider merging it anytime soon or if there are still discrepancies in the implementation you would like to discuss? Otherwise I would really like to see this laying in -next a few weeks before being sent out to Linus, just in case. Thanks, Miquèl
