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

[JiÅÃ Prchal]

I changed manually .config,
now it's there:
[    1.195312] spi spi0.0: gpio_request: 23
[    1.195312] spi spi0.1: gpio_request: 22
[    1.199218] spi spi0.2: gpio_request: 93
[    1.203125] spi spi0.3: gpio_request: 14

But still not working.

Dne 25.7.2014 v 09:53 Boris BREZILLON napsal(a):
> On Fri, 25 Jul 2014 08:14:40 +0200
> JiÅÃ Prchal <jiri.prchal@xxxxxxxxxxx> wrote:
>
> > Dne 24.7.2014 v 17:58 Boris BREZILLON napsal(a):
> > > On Thu, 24 Jul 2014 17:06:43 +0200
> > > JiÅÃ Prchal <jiri.prchal@xxxxxxxxxxx> wrote:
> > >
> > > > Hi,
> > > >
> > > > Dne 24.7.2014 v 16:26 Boris BREZILLON napsal(a):
> > > > > Hello JiÅÃ,
> > > > >
> > > > > 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
> > > > > JiÅÃ Prchal <jiri.prchal@xxxxxxxxxxx> 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.
> > >
> > > Are you using a 9x5ek board or a custom one, in the latter case could
> > > you paste your spi0 node definition ?
> > I'm using custom board. My spi node:
> > 			spi0: spi@f0000000 {
> > 				status = "okay";
> > 				cs-gpios = <&pioA 23 0
> > 					    &pioA 22 0
> > 					    &pioC 29 0
> > 					    &pioA 14 0>;
> >
> > 				fm25@0 {
> > 					compatible = "cypress,fm25";
> > 					spi-max-frequency = <40000000>;
> > 					reg = <0>;
> > 					pagesize = <256>;
> > 					size = <131072>;
> > 					address-width = <24>;
> > 				};
> > 				/* ADC */
> > 				spidev@1 {
> > 					compatible = "spidev";
> > 					reg = <1>;
> > 					spi-max-frequency = <1000000>;
> > 				};
> > 				/* IO expander for busaddr */
> > 				spidev@2 {
> > 					compatible = "spidev";
> > 					reg = <2>;
> > 					label = "busaddr";
> > 					spi-max-frequency = <10000000>;
> > 				};
> > 				/* audio codec */
> > 				codec: codec@3 {
> > 					compatible = "ti,tlv320aic3x";
> > 					spi-max-frequency = <1000000>;
> > 					reg = <3>;
> > 				};
> > 			};
> >
> > This does not work without patch, because of 2 chips selected at one time because of PA14 is periph_a. Probably ROMBOOT
> > changes that.
>
> Yes, boot code stored in ROM probably mux PA14 to periph A function,
> but with your definition PA 14 should be set GPIO mode when the codec
> device is created.
>
> I don't see any obvious error in your definition, could you add a trace
> there [1] to see if the gpio is successfully requested ?
> Could you also paste the content of /sys/kernel/debug/gpio ?
>
> > > > > 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.
> > >
> > > If you want PA14 to control cs1 and PA22 to control cs0 (both
> > > configured as GPIOs), you'll have the following definition:
> > >
> > > cs-gpios = <&pioA 22 0>, <&pioA 14 0>, <0>, <0>;
> > See my node.
> > > > > 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.
> > >
> > > Take a look at [1], which is set as the gpio_request_enable callback,
> > > called by pinctrl core when a gpio is requested.
> > But is this called from spi driver when requesting gpios as cs?
>
> Yes, it's part of the gpio_request process:
> gpio_request calls request method on at91 gpio_chip which in turn
> calls pinctrl_request_gpio which then calls the gpio_request_enable
> method I previously mentioned.
>
>
> Best Regards,
>
> Boris
>
> [1]http://lxr.free-electrons.com/source/drivers/spi/spi-atmel.c#L1031
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