Re: [PATCH 01/23] dt-bindings: introduce silabs,wfx.yaml

From: Rob Herring
Date: Tue Oct 13 2020 - 12:49:40 EST


On Mon, Oct 12, 2020 at 12:46:26PM +0200, Jerome Pouiller wrote:
> From: Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx>
>
> Signed-off-by: Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx>
> ---
> .../bindings/net/wireless/silabs,wfx.yaml | 125 ++++++++++++++++++
> 1 file changed, 125 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/net/wireless/silabs,wfx.yaml
>
> diff --git a/Documentation/devicetree/bindings/net/wireless/silabs,wfx.yaml b/Documentation/devicetree/bindings/net/wireless/silabs,wfx.yaml
> new file mode 100644
> index 000000000000..43b5630c0407
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/wireless/silabs,wfx.yaml
> @@ -0,0 +1,125 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (c) 2020, Silicon Laboratories, Inc.
> +%YAML 1.2
> +---
> +
> +$id: http://devicetree.org/schemas/net/wireless/silabs,wfx.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Silicon Labs WFxxx devicetree bindings
> +
> +maintainers:
> + - Jérôme Pouiller <jerome.pouiller@xxxxxxxxxx>
> +
> +description:
> + The WFxxx chip series can be connected via SPI or via SDIO.

What does this chip do? WiFi or some other wireless?

> +
> + For SDIO':'
> +
> + The driver is able to detect a WFxxx chip on SDIO bus by matching its Vendor
> + ID and Product ID. However, driver will only provide limited features in
> + this case. Thus declaring WFxxx chip in device tree is recommended (and may
> + become mandatory in the future).
> +
> + In addition, it is recommended to declare a mmc-pwrseq on SDIO host above
> + WFx. Without it, you may encounter issues with warm boot. The mmc-pwrseq
> + should be compatible with mmc-pwrseq-simple. Please consult
> + Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt for more
> + information.
> +
> + For SPI':'
> +
> + In add of the properties below, please consult
> + Documentation/devicetree/bindings/spi/spi-controller.yaml for optional SPI
> + related properties.
> +
> + Note that in add of the properties below, the WFx driver also supports
> + `mac-address` and `local-mac-address` as described in
> + Documentation/devicetree/bindings/net/ethernet.txt

Note what ethernet.txt contains... This should have a $ref to
ethernet-controller.yaml to express the above.

You can add 'mac-address: true' if you want to be explicit about what
properties are used.

> +
> +properties:
> + compatible:
> + const: silabs,wf200

blank line between each DT property.

> + reg:
> + description:
> + When used on SDIO bus, <reg> must be set to 1. When used on SPI bus, it is
> + the chip select address of the device as defined in the SPI devices
> + bindings.
> + maxItems: 1
> + spi-max-frequency:
> + description: (SPI only) Maximum SPI clocking speed of device in Hz.

No need to redefine a common property.

> + maxItems: 1

Not an array. Just need:

spi-max-frequency: true

> + interrupts:
> + description: The interrupt line. Triggers IRQ_TYPE_LEVEL_HIGH and
> + IRQ_TYPE_EDGE_RISING are both supported by the chip and the driver. When
> + SPI is used, this property is required. When SDIO is used, the "in-band"
> + interrupt provided by the SDIO bus is used unless an interrupt is defined
> + in the Device Tree.
> + maxItems: 1
> + reset-gpios:
> + description: (SPI only) Phandle of gpio that will be used to reset chip
> + during probe. Without this property, you may encounter issues with warm
> + boot. (For legacy purpose, the gpio in inverted when compatible ==
> + "silabs,wfx-spi")
> +
> + For SDIO, the reset gpio should declared using a mmc-pwrseq.
> + maxItems: 1
> + wakeup-gpios:
> + description: Phandle of gpio that will be used to wake-up chip. Without this
> + property, driver will disable most of power saving features.
> + maxItems: 1
> + config-file:
> + description: Use an alternative file as PDS. Default is `wf200.pds`. Only
> + necessary for development/debug purpose.

'firmware-name' is typically what we'd use here. Though if just for
debug/dev, perhaps do a debugfs interface for this instead. As DT should
come from the firmware/bootloader, requiring changing the DT for
dev/debug is not the easiest workflow compared to doing something from
userspace.

> + maxItems: 1

Looks like a string, not an array.

> +
> +required:
> + - compatible
> + - reg

Will need additionalProperties or unevaluatedProperties depending on
whether you list out properties from ethernet-controller.yaml or not.

Rob