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Message-Id: <1EB953D9-8221-47A0-9025-0C39DD09B631@jcrosoft.com>
Date: Fri, 1 Aug 2014 01:05:24 +0800
From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>
To: Alexandre Belloni <alexandre.belloni@...e-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@...osoft.com>,
Boris BREZILLON <boris.brezillon@...e-electrons.com>,
devicetree@...r.kernel.org,
Jiří Prchal <jiri.prchal@...ignal.cz>,
Nicolas FERRE <nicolas.ferre@...el.com>,
linux-kernel@...r.kernel.org, Mark Brown <broonie@...nel.org>,
voice.shen@...el.com, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] ARM: at91: spi: request all csgpio in spi probe
On Aug 1, 2014, at 12:48 AM, Alexandre Belloni <alexandre.belloni@...e-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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