Re: [PATCH 3/6] dt-bindings: bus: Add documentation for the Technologic Systems NBUS

From: Rob Herring
Date: Mon Dec 19 2016 - 17:12:54 EST


On Wed, Dec 14, 2016 at 06:12:33PM -0500, Sebastien Bourdelin wrote:
> Add binding documentation for the Technologic Systems NBUS that is used
> to interface with peripherals in the FPGA of the TS-4600 SoM.
>
> Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@xxxxxxxxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/bus/ts-nbus.txt | 50 +++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/bus/ts-nbus.txt
>
> diff --git a/Documentation/devicetree/bindings/bus/ts-nbus.txt b/Documentation/devicetree/bindings/bus/ts-nbus.txt
> new file mode 100644
> index 0000000..2f777ee
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/ts-nbus.txt
> @@ -0,0 +1,50 @@
> +Technologic Systems NBUS
> +
> +The NBUS is a bus used to interface with peripherals in the Technologic
> +Systems FPGA on the TS-4600 SoM.
> +
> +Required properties :
> + - compatible : "technologic,ts-nbus", "simple-bus"
> + - #address-cells : must be 1
> + - #size-cells : must be 0
> + - pws : The PWM pin connected to the clock line on the FPGA

Using PWM binding?

> + - data-gpios : The GPIO pin connected to the data line on the FPGA
> + - csn-gpios : The GPIO pin connected to the csn line on the FPGA
> + - txrx-gpios : The GPIO pin connected to the txrx line on the FPGA
> + - strobe-gpios : The GPIO pin connected to the stobe line on the FPGA
> + - ale-gpios : The GPIO pin connected to the ale line on the FPGA
> + - rdy-gpios : The GPIO pin connected to the rdy line on the FPGA

These all need vendor prefix.

This is not any sort of standard bus?

> +
> +Child nodes:
> +
> +The NBUS node can contain zero or more child nodes representing peripherals
> +on the bus.
> +
> +Example:
> +
> + nbus {
> + compatible = "technologic,ts-nbus", "simple-bus";

I don't think simple-bus is really valid here. Don't you need the nbus
driver before the devices are usable?

> + pinctrl-0 = <&nbus_pins>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + pwms = <&pwm 2 83>;
> + data-gpios = <&gpio0 0 GPIO_ACTIVE_HIGH
> + &gpio0 1 GPIO_ACTIVE_HIGH
> + &gpio0 2 GPIO_ACTIVE_HIGH
> + &gpio0 3 GPIO_ACTIVE_HIGH
> + &gpio0 4 GPIO_ACTIVE_HIGH
> + &gpio0 5 GPIO_ACTIVE_HIGH
> + &gpio0 6 GPIO_ACTIVE_HIGH
> + &gpio0 7 GPIO_ACTIVE_HIGH>;
> + csn-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
> + txrx-gpios = <&gpio0 24 GPIO_ACTIVE_HIGH>;
> + strobe-gpios = <&gpio0 25 GPIO_ACTIVE_HIGH>;
> + ale-gpios = <&gpio0 26 GPIO_ACTIVE_HIGH>;
> + rdy-gpios = <&gpio0 21 GPIO_ACTIVE_HIGH>;
> +
> + wdt@2a {

watchdog@...

> + compatible = "...";
> +
> + /* ... */
> + };
> + };
> --
> 2.10.2
>
> --
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