Re: [PATCH v4 1/2] usb: dwc3: core: add support for RTK SoC custom's global register start address

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, May 03, 2023, Stanley Chang[昌育德] wrote:
> Hi Thinh,
> 
> > I think you're overcomplicating things here.
> > 
> > Can we just match using compatible string as mentioned before? I believe I
> > suggested to use that before but I think you had issue we getting it because it's
> > from the parent device?
> > 
> > Did you try this?
> > 
> >         dwc_res.start = DWC3_RTK_ABC_GLOBAL_OFFSET;
> > 
> >         if (dev->of_node) {
> >                 struct device_node *parent =
> > of_get_parent(dev->of_node);
> > 
> >                 if (of_device_is_compatible(parent, "your-compatible"))
> >                         dwc_res.start =
> > DWC3_RTK_ABC_GLOBAL_OFFSET;
> > 
> >                 of_node_put(parent);
> >         }
> 
> This is a good idea. Thanks for your suggestion.
> This patch works fine and it is simply. 
> For the compatible name, I use that "realtek,rtd1xxx-dwc3". 
> rtd1xxx is the name of SoCs, for rtd129x, rtd139x, rtd16xx, ... etc.
> Do you have any concern?

I think it's fine.

> 
> New patch as follows
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 0beaab932e7d..cd4b69541776 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1800,6 +1800,17 @@ static int dwc3_probe(struct platform_device *pdev)
>         dwc_res = *res;
>         dwc_res.start += DWC3_GLOBALS_REGS_START;
> 
> +       if (dev->of_node) {
> +               struct device_node *parent = of_get_parent(dev->of_node);
> +
> +               if (of_device_is_compatible(parent, "realtek,rtd1xxx-dwc3")) {
> +                       dwc_res.start -= DWC3_GLOBALS_REGS_START;
> +                       dwc_res.start += RTK_RTD1XXX_DWC3_GLOBALS_REGS_START;
> +               }
> +
> +               of_node_put(parent);
> +       }
> +
>         regs = devm_ioremap_resource(dev, &dwc_res);
>         if (IS_ERR(regs))
>                 return PTR_ERR(regs);
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index d56457c02996..db48aae211be 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -84,6 +84,8 @@
>  #define DWC3_OTG_REGS_START            0xcc00
>  #define DWC3_OTG_REGS_END              0xccff
> 
> +#define RTK_RTD1XXX_DWC3_GLOBALS_REGS_START    0x8100

Let's keep consistent with the DWC3_ prefix. Something like this:

#define DWC3_RTK_RTD1XXX_GLOBAL_REGS_START 0x8100

> +
>  /* Global Registers */
>  #define DWC3_GSBUSCFG0         0xc100
>  #define DWC3_GSBUSCFG1         0xc104
> 

Thanks,
Thinh