[RESEND v3 4/4] mtd: rawnand: arasan: Leverage additional GPIO CS

[Miquel Raynal]

On Wed, 2021-05-26 at 09:32:42 UTC, Miquel Raynal wrote:
> Make use of the cs-gpios DT property as well as the core helper to parse
> it so that the Arasan controller driver can now assert many more chips
> than natively.
> 
> The Arasan controller has an internal limitation: RB0 is tied to CS0 and
> RB1 is tied to CS1. Hence, it is possible to use external GPIOs as long
> as one or the other native CS is not used (or configured to be driven as
> a GPIO) and that all additional CS are physically wired on its
> corresponding RB line. Eg. CS0 is used as a native CS, CS1 is not used
> as native CS and may be used as a GPIO CS, CS2 is an additional GPIO
> CS. Then the target asserted by CS0 should also be wired to RB0, while
> the targets asserted by CS1 and CS2 should be wired to RB1.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next.

Miquel