Messages in this thread | | | Subject | Re: [PATCH] ARM: at91: spi: request all csgpio in spi probe | From | Jean-Christophe PLAGNIOL-VILLARD <> | Date | Fri, 1 Aug 2014 01:05:24 +0800 |
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On Aug 1, 2014, at 12:48 AM, Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:
> > On 01/08/2014 at 00:10:05 +0800, Jean-Christophe PLAGNIOL-VILLARD wrote : >>>>> While this solves the particular issue Jiří 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.
here it’s the same issue if you need to pin as GPIO use the GPIO API not the pinctrl
AT91_PERIPH_GPIO is use the set specific pinmux (bouncing & etc…)
> >> 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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