Re: [v3 4/4] spi: aspeed: Add ASPEED FMC/SPI memory controller driver

Mark Brown
2020-11-05T16:43:28Z

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On Thu, Nov 05, 2020 at 04:11:32PM +0100, Boris Brezillon wrote:
> Cédric Le Goater <clg@kaod.org> wrote:

> > Thanks for this driver. It's much cleaner than the previous and we should
> > try adding support for the AST2500 SoC also. I guess we can keep the old
> > driver for the AST2400 which has a different register layout.
> >
> > On the patchset, I think we should split this patch in three :
> >
> > - basic support
> > - AHB window calculation depending on the flash size
> > - read training support

> I didn't look closely at the implementation, but if the read training
> tries to read a section of the NOR, I'd recommend exposing that feature
> through spi-mem and letting the SPI-NOR framework trigger the training
> instead of doing that at dirmap creation time (remember that spi-mem is
> also used for SPI NANDs which use the dirmap API too, and this training
> is unlikely to work there).

> The SPI-NOR framework could pass a read op template and a reference
> pattern such that all the spi-mem driver has to do is execute the
> template op and compare the output to the reference buffer.

That seems like a good idea.

> > We should avoid magic values when setting registers. This is confusing
> > and defines are much better.

It does depend a bit on documentation though, it's not a hard
requirement.

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