[PATCH] ARM: at91: at91sam9x5: sets NPCS0 (PA14) back to GPIO
boris.brezillon at free-electrons.com
Thu Jul 24 07:26:45 PDT 2014
First of all, please try to use git format-patch when submitting a
patch to any kernel mailing list.
On Thu, 24 Jul 2014 15:38:24 +0200
Jiří Prchal <jiri.prchal at aksignal.cz> wrote:
> After ROMBOOT tries boot from flash on SPI0 NPCS0, this NPCS0 (PA14) remains set to PERIPH_A.
> Because of that, this pin is unusable to something else.
> This patch sets it back to GPIO.
The policy is to leave pins in an unknown state till some peripheral
What are you trying to use this pin for ?
If you just want to use it as a chip select for an spi device, take a
look at .
Here the gpio is requested by the spi core when defining the cs-gpios
property. The gpio controller then request the listed pins to the pin
controller (pinctrl driver).
You can explicitly define a new pinctrl state (by defining a new
pinctrl_spi0_cs0 subnode in your dts file) and reference it in the
spi0 node, though this is not mandatory.
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
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