On Thu, 19 Jul 2018 01:57:03 +0200
Janusz Krzysztofik [off-list ref] wrote:

Introduce a driver private structure and allocate it on device probe.
Use it for storing nand_chip structure, GPIO descriptors prevoiusly
stored in static variables as well as io_base pointer previously passed
as nand controller data or platform driver data.

That's a good thing. Thanks for doing that.

Subsequent patches
may populate the structure with more members as needed.

While at it, fix missing mtd->dev.parent and drop useless mtd->owner.

I'd prefer to have it done in a separate patch if you don't mind.