(EXT) Re: [PATCH] spi-imx: remove num-cs support, set num_chipselect to 4

Fabio Estevam festevam at gmail.com
Fri Sep 4 09:57:13 EDT 2020

On Fri, Sep 4, 2020 at 10:02 AM Matthias Schiffer
<matthias.schiffer at ew.tq-group.com> wrote:

> This would make num_chipselect default to 1 again (set by
> __spi_alloc_controller()), breaking every i.MX board that uses more
> than 1 native CS.

Which boards are that? Are you referring to non-DT i.MX boards?

If so, I have sent a patch removing all non-DT i.MX boards.

> I'm aware that using cs-gpios instead of native CS is probably a good
> idea in any case, as the native CS of this SPI controller is kinda
> flaky (and at a glance it looks like all in-tree DTs do this; not sure
> about board files that don't use DTs?), but I'm not convinced that
> breaking native CS support completely is desirable either.

Initial i.MX chips with this SPI IP had issues in using chip-select in
native mode and GPIO chip-select has been used since them.

Do we have i.MX dts that make use of native chip select?

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