Re: [PATCH] ARM: at91: at91sam9x5: sets NPCS0 (PA14) back to GPIO

[JiÅÃ Prchal]

Dne 25.7.2014 v 10:54 Alexandre Belloni napsal(a):
> On 25/07/2014 at 10:37:31 +0200, JiÅÃ Prchal wrote :
> > Dne 25.7.2014 v 10:30 Alexandre Belloni napsal(a):
> > > Hi,
> > >
> > > On 25/07/2014 at 08:14:40 +0200, JiÅÃ Prchal wrote :
> > > > I'm using custom board. My spi node:
> > > > 			spi0: spi@f0000000 {
> > >
> > > You should override the pinctrl here as you are using gpios for the cs.
> > > 				pinctrl-0 = <&pinctrl_spi0_custom>;
> > >
> > > > 				status = "okay";
> > > > 				cs-gpios = <&pioA 23 0
> > > > 					    &pioA 22 0
> > > > 					    &pioC 29 0
> > > > 					    &pioA 14 0>;
> > >
> > > 		pinctrl@fffff400 {
> > > 				spi0 {
> > > 					 pinctrl_spi0_custom: spi0-custom {
> > > 							 atmel,pins =
> > > 									 <AT91_PIOA 23 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>,
> > > 									 <AT91_PIOA 22 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>,
> > > 									 <AT91_PIOC 29 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>,
> > > 									 <AT91_PIOA 14 AT91_PERIPH_GPIO AT91_PINCTRL_NONE>;
> > > 					 };
> > > 				};
> > > 		};
> > Of course, it's the way, but in all other drivers, for example LEDS,
> > it's not needed. And in other way, if I will not use PA14 at all,
> > the pin will goes down every spi transfer.
>
> You must not assumed that the pins are muxed to their default state
> which is gpio and you should set the pinctrl accordingly for each
> device.
>
> If you don't use PA14 at all, then you don't really care about its
> state...
Yes and no, what about on board is populated some chip on PA14, but for some reason at this time I don't need it and not 
defined in DT?
>
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