Re: [PATCH v2 1/2] dt-bindings: usb: Introduce ITE IT5205 Alt. Mode Passive MUX

AngeloGioacchino Del Regno
2024-01-22T10:27:29Z

Il 19/01/24 17:18, Conor Dooley ha scritto:
> On Fri, Jan 19, 2024 at 01:58:11PM +0100, AngeloGioacchino Del Regno wrote:
>> Introduce a binding for the ITE IT5205 Alternate Mode Passive MUX,
>> used for connecting, disconnecting and switching orientation and
>> control the SBU signals for alternate modes on USB Type-C ports.
>>
>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> ---
>> .../devicetree/bindings/usb/ite,it5205.yaml | 72 +++++++++++++++++++
>> 1 file changed, 72 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/usb/ite,it5205.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/usb/ite,it5205.yaml b/Documentation/devicetree/bindings/usb/ite,it5205.yaml
>> new file mode 100644
>> index 000000000000..36ec4251b5f2
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/ite,it5205.yaml
>> @@ -0,0 +1,72 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/usb/ite,it5205.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: ITE IT5202 Type-C USB Alternate Mode Passive MUX
>> +
>> +maintainers:
>> + - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> + - Tianping Fang <tianping.fang@mediatek.com>
>> +
>> +properties:
>> + compatible:
>> + const: ite,it5205
>> +
>> + reg:
>> + maxItems: 1
>> +
>> + vcc-supply:
>> + description: Power supply for VCC pin (3.3V)
>> +
>> + mode-switch:
>> + description: Flag the port as possible handle of altmode switching
>> + type: boolean
>> +
>> + orientation-switch:
>> + description: Flag the port as possible handler of orientation switching
>> + type: boolean
>> +
>> + ite,ovp-enable:
>> + description: Enable Over Voltage Protection functionality
>> + type: boolean
>
> Bitta devil's advocacy perhaps, but why is this DT property? Is it not
> known whether or not this is supported based on the compatible, and
> whether or not to enable it is a decision for the operating system to
> make?
>
>

AFAIK, not all board designs can use the OVP. On some, this may be unstable - the
use case where this can be safely enabled is when there's nothing in between the
mux and the controller, and between the mux and the port.

Cheers,
Angelo