Re: [PATCH v3 lora-next 4/4] dt-bindings: lora: sx130x: add clock bindings

[Ben Whitten]

Missed linux-lpwan

On Thu, 24 Jan 2019 at 14:53, Ben Whitten <ben.whitten@xxxxxxxxx> wrote:
>
> From: Ben Whitten <ben.whitten@xxxxxxxxx>
>
> The SX130x family consumes two clocks, a 32 MHz clock provided by a
> connected IQ transceiver, and a 133 MHz high speed clock.
> It also provides a 32 MHz clock out to the radio in the TX path.
>
> In the example we connect the concentrator to a fixed clock providing
> the 133 MHz high speed clock, and we connect to a connected transceiver
> 32 MHz clock.
>
> A radio in the TX path is also connected to the 32 MHz clock out from the
> concentrator.
>
> The connected radios are both fed from a fixed 32 MHz clock, with only
> one being the clock source back to the SX130x concentrator.
>
> Signed-off-by: Ben Whitten <ben.whitten@xxxxxxxxx>
> ---
> v2 -> v3:
> * Name input clocks specifically
> * Add output clock for radio in TX path
> v1 -> v2:
> * Fixed incorrect usage of clock cells
> * Fixed wording in commit and descriptions
> ---
>  .../bindings/net/lora/semtech,sx130x.yaml     | 52 ++++++++++++++++++-
>  1 file changed, 51 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml b/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml
> index 24fad1218735..5d32668d6ca9 100644
> --- a/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml
> +++ b/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml
> @@ -15,7 +15,9 @@ description: |
>    demodulating LoRa signals on 8 channels simultaneously.
>
>    It is typically paired with two SX125x IQ radios controlled over an
> -  SPI directly from the concentrator.
> +  SPI directly from the concentrator. One of the radios will provide
> +  a 32 MHz clock back into the concentrator.
> +  The concentrator also outputs a 32 MHz clock to the radio(s) in the TX chain.
>
>    The concentrator itself is controlled over SPI.
>
> @@ -37,6 +39,30 @@ properties:
>      maxItems: 1
>      description: A connection of the reset gpio line.
>
> +  clocks:
> +    maxItems: 2
> +    items:
> +      - description: 32 MHz clock provider (CLK32M)
> +      - description: 133 MHz high speed clock provider (CLKHS)
> +    description: The chip requires two clock inputs; A 32MHz clock at CMOS
> +      level which is provided from a connected radio.
> +      And a 133MHz high speed clock at CMOS level provided by an oscillator.
> +
> +  clock-names:
> +    items:
> +      - const: clk32m
> +      - const: clkhs
> +    description: Input clock (CLK32M) name from provider, Input clock (CLKHS)
> +      name from provider.
> +
> +  clock-output-names:
> +    items:
> +      - const: sp_clk_out
> +    description: Output clock (SP_CLK_OUT) typically connected to the TX radio.
> +
> +  '#clock-cells':
> +    const: 0
> +
>    radio-spi:
>      type: object
>      description: The concentrator can have two radios connected which are
> @@ -73,6 +99,20 @@ examples:
>
>      #include <dt-bindings/gpio/gpio.h>
>
> +    tcxo: dummy32m {
> +      compatible = "fixed-clock";
> +      clock-frequency = <32000000>;
> +      clock-output-names = "tcxo";
> +      #clock-cells = <0>;
> +    };
> +
> +    clkhs: dummy133m {
> +      compatible = "fixed-clock";
> +      clock-frequency = <133000000>;
> +      clock-output-names = "clkhs";
> +      #clock-cells = <0>;
> +    };
> +
>      spi {
>        #address-cells = <1>;
>        #size-cells = <0>;
> @@ -82,6 +122,10 @@ examples:
>          reg = <0>;
>          reset-gpios = <&pioB 27 GPIO_ACTIVE_HIGH>;
>          spi-max-frequency = <8000000>;
> +        clocks = <&radio1>, <&clkhs>;
> +        clock-names = "clk32m", "clkhs";
> +        clock-output-names = "sp_clk_out";
> +        #clock-cells = <0>;
>
>          radio-spi {
>            #address-cells = <1>;
> @@ -90,11 +134,17 @@ examples:
>            radio0: radio@0 {
>              compatible = "semtech,sx1257";
>              reg = <0>;
> +            clocks = <&tcxo>, <&concentrator0>;
> +            clock-names = "fxosc", "fclk_in";
>            };
>
>            radio1: radio@1 {
>              compatible = "semtech,sx1257";
>              reg = <1>;
> +            clocks = <&tcxo>;
> +            clock-names = "fxosc";
> +            clock-output-names = "fclk_out";
> +            #clock-cells = <0>;
>            };
>          };
>        };
> --
> 2.17.1
>