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Subject[PATCH v2 lora-next 4/4] dt-bindings: lora: sx130x: add clock bindings
Date
From: Ben Whitten <ben.whitten@gmail.com>

The SX130x family consumes two clocks, a 32 MHz clock provided by a
connected IQ transceiver, and a 133 MHz high speed clock.

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.

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@gmail.com>
---
v1 -> v2:
* Fixed incorrect usage of clock cells
* Fixed wording in commit and descriptions
---
.../bindings/net/lora/semtech,sx130x.yaml | 39 ++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml b/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml
index 41919fb67ec4..6f9db3c84385 100644
--- a/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml
+++ b/Documentation/devicetree/bindings/net/lora/semtech,sx130x.yaml
@@ -15,7 +15,8 @@ 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 itself is controlled over SPI.

@@ -35,6 +36,20 @@ 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:
+ maxItems: 2
+ description: Input clock (CLK32M) name from provider, Input clock (CLKHS)
+ name from provider.
+
radio-spi:
type: object
description: The concentrator can have two radios connected which are
@@ -68,6 +83,20 @@ 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>;
@@ -77,6 +106,8 @@ examples:
reg = <0>;
reset-gpios = <&pioB 27 GPIO_ACTIVE_HIGH>;
spi-max-frequency = <8000000>;
+ clocks = <&radio1>, <&clkhs>;
+ clock-names = "clk32m", "clkhs";

radio-spi {
#address-cells = <1>;
@@ -85,11 +116,17 @@ examples:
radio0: lora@0 {
compatible = "semtech,sx1257";
reg = <0>;
+ clocks = <&tcxo>;
+ clock-names = "tcxo";
};

radio1: lora@1 {
compatible = "semtech,sx1257";
reg = <1>;
+ clocks = <&tcxo>;
+ clock-names = "tcxo";
+ clock-output-names = "clk32m";
+ #clock-cells = <0>;
};
};
};
--
2.17.1
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