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
>
