RE: [PATCH 6/6] dt-bindings: spi: Document Renesas SPIBSC bindings

[Chris Brandt <Chris.Brandt@xxxxxxxxxxx>]

Hi Geert,

On Thu, Dec 5, 2019 1, Geert Uytterhoeven wrote:
> Your spibsc driver does:
> 
>     master->mode_bits = SPI_CPOL | SPI_CPHA;
> 
> i.e. SPI_[TR]X_{QUAD,DUAL} are not set, so it should not try those modes.

OK, Thank you!
 
> At least on RSK+RZA1, the FLASHes are wired in quad mode, so you should
> describe the hardware in DT.

OK.

> > > BTW, when using spibsc in direct-mapped mode: if you turn of and on
> > > again the module clock, does the spibsc need reprogramming?
> >
> > Nope. Everything will stay the same (just like all the other peripherals).
> The only thing you 'might' want to do is flush the read cache (especially if
> you disconnected it because you were going to go out and re-write some of the
> flash in SPI mode).
> 
> Good. So that means the MTD driver can be modular.  Unused clocks are turned
> off at boot, and can be turned on when the mtd-rom driver is loaded and
> activated.

I'm going to do some testing now and then send out a V2 to see if we are
getting closer to a consensus.

Chris