Re: [PATCH 0/3] dt-bindings: connector: usb: provide bindings for altmodes

From: Konrad Dybcio
Date: Wed Nov 15 2023 - 11:21:27 EST




On 11/13/23 23:13, Dmitry Baryshkov wrote:
On Mon, 13 Nov 2023 at 18:07, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:

Hi Dmitry,

On 11/13/23 15:33, Dmitry Baryshkov wrote:
In some cases we need a way to specify USB-C AltModes that can be
supportd on the particular USB-C connector. For example, x86 INT33FE
driver does this by populating fwnode properties internally. For the
Qualcomm Robotics RB5 platform (and several similar devices which use
Qualcomm PMIC TCPM) we have to put this information to the DT.

Provide the DT bindings for this kind of information and while we are at
it, change svid property to be 16-bit unsigned integer instead of a
simple u32.

Thank you for your patches. I'm fine with this, one remark though:

Since at least the existing arch/arm64/boot/dts/qcom/qrb5165-rb5.dts
is already using this I'm not sure of changing the svid property to
an u16 is really a good idea from devicetree compatibility pov ?

Usually we try to keep DT compatible, that's true. And I also do not
fully like the u16 notation. However I'm not sure whether using full
u32 for explicitly u16 value is correct. I'll wait for the guidance
from DT binding and USB maintainers.

I'll mention the qrb5165-rb5 explicitly in the cover letter.
I'd say it's fine since it was incorrect from the start (+ bindings
shouldn't describe linux's flaws)

Konrad