Re: [PATCH 03/11] dt-bindings: usb: mtk-xhci: add compatible for mt8195

["Chunfeng Yun (云春峰)" <Chunfeng.Yun@mediatek.com>]

On Fri, 2021-08-06 at 14:43 -0600, Rob Herring wrote:
> On Fri, Jul 30, 2021 at 04:49:54PM +0800, Chunfeng Yun wrote:
> > There are 4 USB controllers on MT8195, the controllers (IP1~IP3,
> > exclude IP0) have a wrong default SOF/ITP interval which is
> > calculated from the frame counter clock 24Mhz by default, but
> > in fact, the frame counter clock is 48Mhz, so we should set
> > the accurate interval according to 48Mhz. Here add a new compatible
> > for MT8195, it's also supported in driver. But the first controller
> > (IP0) has no such issue, we prefer to use generic compatible,
> > e.g. mt8192's compatible.
> 
> That only works until you find some 8195 bug common to all
> instances. 
It's also OK for IP0 to use mt8195's compatible, these setting value is
the same as IP0's default value, use mt8192's may avoid these dummy
setting.

> Can't you read the clock frequency?
No, it may be divided internally, not the same as the clock source.

> 
> > 
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> >  Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > xhci.yaml
> > index 61a0e550b5d6..753e043e5327 100644
> > --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > @@ -31,6 +31,7 @@ properties:
> >            - mediatek,mt8173-xhci
> >            - mediatek,mt8183-xhci
> >            - mediatek,mt8192-xhci
> > +          - mediatek,mt8195-xhci
> >        - const: mediatek,mtk-xhci
> >  
> >    reg:
> > -- 
> > 2.18.0
> > 
> >