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

[Dmitry Baryshkov]

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.

>
> Also the whole 16 bit property notation in the dts files seems
> less readable to me. So to me this seems more of something
> which one would use when having a significantly sized array
> of u16-s since then it will result in space-saving in the dtb.
>
> In this case I personally think it is fine to leave this
> as an u32.
>
> With all that said, I'm fine either way.
>
> Here is my ack for routing the drivers/platform/x86/intel/chtwc_int33fe.c
> bits through whatever tree is best to get this upstream:
>
> Acked-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>
> Regards,
>
> Hans
>
>
>
>
> > Dmitry Baryshkov (3):
> >   dt-bindings: connector: usb: add altmodes description
> >   usb: typec: change altmode SVID to u16 entry
> >   arm64: dts: qcom: qrb5165-rb5: use u16 for DP altmode svid
> >
> >  .../bindings/connector/usb-connector.yaml     | 35 +++++++++++++++++++
> >  arch/arm64/boot/dts/qcom/qrb5165-rb5.dts      |  2 +-
> >  drivers/platform/x86/intel/chtwc_int33fe.c    |  2 +-
> >  drivers/usb/typec/class.c                     |  5 +--
> >  4 files changed, 40 insertions(+), 4 deletions(-)
> >
>


-- 
With best wishes
Dmitry