Re: [PATCH lora-next 1/4] dt-bindings: lora: sx130x: add basic documentation
flat view
From: Andreas Färber <afaerber@suse.de>
Date: 2019-01-12 03:37:13
Also in:
linux-devicetree, lkml
Hi Ben, Am 08.01.19 um 09:41 schrieb Ben Whitten:
Add basic documentation in YAML format for the sx130x series concentrators from Semtech. Required is; the location on the SPI bus, the reset gpio and the node for downstream IQ radios, typically sx125x. Signed-off-by: Ben Whitten <redacted> --- .../bindings/lora/semtech,sx130x.yaml | 87 +++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 Documentation/devicetree/bindings/lora/semtech,sx130x.yaml
Patch 3/4 moves this to net/lora/, which I think is more appropriate.
quoted hunk ↗ jump to hunk
diff --git a/Documentation/devicetree/bindings/lora/semtech,sx130x.yaml b/Documentation/devicetree/bindings/lora/semtech,sx130x.yaml new file mode 100644 index 000000000000..ad263bc4e60d --- /dev/null +++ b/Documentation/devicetree/bindings/lora/semtech,sx130x.yaml@@ -0,0 +1,87 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/lora/semtech,sx130x.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Semtech LoRa concentrator + +maintainers: + - Andreas Färber <afaerber@suse.de> + - Ben Whitten <ben.whitten@gmail.com> + +description: | + Semtech LoRa concentrator sx130x digital baseband chip is capable of
SX130x or SX1301/SX1308, to distinguish from driver name sx130x and to avoid ambiguities of which x is a wildcard.
quoted hunk ↗ jump to hunk
+ demodulating LoRa signals on 8 channels simultaneously. + + It is typically paired with two sx125x IQ radios controlled over an
Ditto, SX125x
quoted hunk ↗ jump to hunk
+ SPI directly from the concentrator. + + The concentrator itself it controlled over SPI. + +properties: + compatible: + items: + - enum: + - semtech,sx1301 + - semtech,sx1308
We should only list both if we expect differences between the two models. Otherwise SX1308 can reuse the SX1301 compatible. If we want to mark it up just in case then rearranging the above to be a sequence of "semtech,sx1308", "semtech,sx1301" would be an alternative.
quoted hunk ↗ jump to hunk
+ + reg: + maxItems: 1 + description: The chip select on the SPI bus.
Is this mandatory now or not with maxItems?
quoted hunk ↗ jump to hunk
+ + reset-gpios: + maxItems: 1 + description: A connection of the reset gpio line.
This needs to be optional, which I think the maxItems syntax says unlike the commit message? On an mPCIe card you won't have such a GPIO, for instance. We do a Soft Reset, so it's not functionally mandatory.
quoted hunk ↗ jump to hunk
+ + spi-max-frequency: + maximum: 10000000 + default: 8000000 + description: The frequency of the SPI communication to the concentrator, + in Hz. Maximum SPI frequency is 10MHz although 8MHz is typically used + on a number of cards.
Do we really need to describe this here? It should be covered in the common SPI bindings, and only applies to SPI bus, not USB picoGW.
quoted hunk ↗ jump to hunk
+ + radio-spi: + description: The concentrator has two radios connected which are contained + within the following node.
"can have"
quoted hunk ↗ jump to hunk
+ + properties: + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + + required: + - '#address-cells' + - '#size-cells'
I'm pretty sure that Rob would like to have a compatible here, even if unneeded in our Linux driver? BTW if someone has better naming suggestions than "radio-spi"... I just wanted to avoid having it in the main node directly, in case we need other sub-nodes, too.
quoted hunk ↗ jump to hunk
+ +required: + - compatible + - reg + - reset-gpios
Must be optional.
+ - radio-spi
Should be optional. (Driver needs it today, but that's another problem.)
quoted hunk ↗ jump to hunk
+ +examples: + - | + concentrator0: lora@0 { + compatible = "semtech,sx1301"; + reg = <0>; + reset-gpios = <&pioB 27 GPIO_ACTIVE_HIGH>; + spi-max-frequency = <8000000>; + + radio-spi { + #address-cells = <1>; + #size-cells = <0>; + + radio0: lora@0 { + compatible = "semtech,sx1257"; + reg = <0>; + }; + + radio1: lora@1 { + compatible = "semtech,sx1257"; + reg = <1>; + }; + }; + };
Thanks for looking into this, Andreas -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg)