Hi,
Dne 24.7.2014 v 16:26 Boris BREZILLON napsal(a):
Hello Jiří,
First of all, please try to use git format-patch when submitting a
patch to any kernel mailing list.
Sorry for that.
On Thu, 24 Jul 2014 15:38:24 +0200
Jiří Prchal <jiri.prc...@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
need them.
What are you trying to use this pin for ?
For chip select, but #3. And when SPI communicate with cs0 (PA22), it goes down too (PA14), so 2 devices on bus were
selected.
If you just want to use it as a chip select for an spi device, take a
look at [1].
At [1] it's OK until as cs0 is for example PA22 and cs1 is PA14.
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).
GPIO is not set in driver as GPIO, at least I didn't find it.
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.
Best Regards,
Boris
[1]http://lxr.free-electrons.com/source/arch/arm/boot/dts/at91sam9x5ek.dtsi#L85
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