[PATCH] pinctrl: dt: at91: new binding

[Ludovic Desroches]

Hi Jean-Christophe,

On Thu, Feb 26, 2015 at 10:34:54AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> Today if we want to disable a pio bank we may will siliently break pinctrl
> configuration in the DT. This will be detected only at runtime.

Do you have a case where it breaks pinctrl? I can do more tests but with
the latest patch "pinctrl: at91: allow to have disabled gpio bank", I
had no issue.

> 
> So move the pinctrl configuration to the bank instead of the bus.
> This allow to detect pinctrl issue at DT compiling time when disable a bank.
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> Cc: Linus Walleij <linus.walleij at linaro.org>
> Cc: devicetree at vger.kernel.org
> ---
>  .../bindings/pinctrl/atmel,at91-pinctrl.txt        | 66 ++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
> index b7a93e8..78355ee 100644
> --- a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
> +++ b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
> @@ -148,3 +148,69 @@ dbgu: serial at fffff200 {
>  	pinctrl-0 = <&pinctrl_dbgu>;
>  	status = "disabled";
>  };
> +
> +II) New Bindings per PIO Block
> +
> +This allow to detect pinctrl issue at DT compiling time when disable a bank
> +
> +Required properties for iomux controller:
> +- compatible: "atmel,at91rm9200-pio-pinctrl" or "atmel,at91sam9x5-pio-pinctrl"
> +		or "atmel,sama5d3-pio-pinctrl"
> +- atmel,mux-mask: array of mask (periph per bank) to describe if a pin can be
> +  configured in this periph mode. All the periph and bank need to be describe.
> +
> +How to create such array:
> +
> +Each column will represent the possible peripheral of the pinctrl for the bank
> +
> +Take an example on the 9260
> +Peripheral: 2 ( A and B)
> +=>
> +
> +  /*    A         B     */
> +  0xffffffff 0xffc00c3b  /* pioA */
> +
> +For each peripheral/bank we will descibe in a u32 if a pin can be
> +configured in it by putting 1 to the pin bit (1 << pin)
> +
> +Required properties for pin configuration node:
> +- atmel,pins: 3 integers array, represents a group of pins mux and config
> +  setting. The format is atmel,pins = <PIN_NUM PERIPH CONFIG>.
> +  The PERIPH 0 means gpio, PERIPH 1 is periph A, PERIPH 2 is periph B...
> +
> +Bits used for CONFIG:
> +cf atmel,at91-pinctrl
> +
> +pioB: gpio at fffff600 {
> +	compatible = "atmel,at91rm9200-gpio", "atmel,at91rm9200-pio-pinctrl";
> +	reg = <0xfffff600 0x200>;
> +	interrupts = <3 IRQ_TYPE_LEVEL_HIGH 1>;
> +	#gpio-cells = <2>;
> +	gpio-controller;
> +	interrupt-controller;
> +	#interrupt-cells = <2>;
> +	clocks = <&pioB_clk>;
> +
> +			 /*    A         B     */
> +	atmel,mux-mask = <0xffffffff 0x7fff3ccf>;
> +
> +	dbgu {
> +		pinctrl_dbgu: dbgu-0 {
> +			atmel,pins =
> +				<14 0x1 0x0	/* PB14 periph A */
> +				 15 0x1 0x1>;	/* PB15 periph A with pullup */
> +		};
> +	};

So we have to update all device tree files, that's a lot of work...
Moreover it adds complexity if we have a device using pins from
different pio controllers.

> +};
> +
> +dbgu: serial at fffff200 {
> +	compatible = "atmel,at91sam9260-usart";
> +	reg = <0xfffff200 0x200>;
> +	interrupts = <1 4 7>;
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pinctrl_dbgu>;
> +	status = "disabled";
> +};
> +
> +if you have to use multiple bank
> +	pinctrl-0 = <&pinctrl_ip_piaa>, <&pinctrl_ip_piab>;

You mean pio I think.


Ludovic