Re: [PATCH 0/2] spi: Correct CS GPIOs polarity when using GPIO descriptors

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On Thu, May 6, 2021 at 2:35 PM Mark Brown <broonie@xxxxxxxxxx> wrote:
> On Thu, May 06, 2021 at 02:24:17PM +0300, Andy Shevchenko wrote:
> > On Thursday, May 6, 2021, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
>
> > > Curious that ACPI has SPI CS as always active high,
>
> > Here I didn’t get what exactly you are pointing out. GPIOs are active high,
> > due to historical reasons. Otherwise SPI CS depends on the actual hardware
> > and may be (most of the cases?) active low.
>
> SPI chip selects are almost always active low - the signal is often
> written nCS or /CS for that reason.

Exactly, and it's not altered with ACPI. That's the whole point of
keeping it active high for _GPIO_ CS case.

-- 
With Best Regards,
Andy Shevchenko




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