Re: [PATCH] ARM: at91: spi: request all csgpio in spi probe

From: Alexandre Belloni
Date: Thu Jul 31 2014 - 12:55:00 EST


On 01/08/2014 at 00:10:05 +0800, Jean-Christophe PLAGNIOL-VILLARD wrote :
> >>> While this solves the particular issue JiÅÃ is seeing, this will not
> >>> solve the case where PA14 (CS0) is not used by the spi driver at all. It
> >>> will remained muxed as CS0 and toggle when the spi master needs to
> >>> access CS0 until another driver muxes it to something else. I still
> >>> believe we should explicitly ask pinctrl to mux them as gpios.
>
> This is not the job of the kernel but to the bootloader
> no the pinctrl binding is not here and will never be here the configure a pin as a GPIO or

This is exactly what AT91_PERIPH_GPIO does though. Anyway, not request
the pinmuxing in the driver is not a good idea, then nothing prevents
another driver to request them to do something completely different.

> to a specific state. This the job of the driver or the bootloader
>

I agree that it must not allow to set the state, we are talking about
muxing.


--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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