Re: [PATCH v6] usb: dwc3: core: add support for realtek SoCs custom's global register start address

[Thinh Nguyen]

On Fri, May 05, 2023, Stanley Chang wrote:
> The Realtek RTD SoCs were designed with the global register address
> offset at 0x8100. The default address offset is constant at
> DWC3_GLOBALS_REGS_START (0xc100). Therefore, add a check if the
> compatible name of the parent is realtek,rtd-dwc3, then global
> register start address will remap to 0x8100.
> 
> Signed-off-by: Stanley Chang <stanley_chang@xxxxxxxxxxx>
> ---
>  v5 to v6 change:
> Change the compatible name to avoid using the wildcard.
> 
>  v4 to v5 change:
> Use the compatible name of the parent to match this special offset.
> 
>  v3 to v4 change:
> Use the compatible name to specify the global register address offset.
> If the compatible name is "snps,dwc3-rtk-soc", then the offset use 0x8100.
> Otherwise, the offset is default value 0xc100.
> 
>  v2 to v3 change:
> 1.  Fix the dtschema validation error.
> 
>  v1 to v2 change:
> 1. Change the name of the property "snps,global-regs-starting-offset".
> 2. Adjust the format of comment.
> 3. Add initial value of the global_regs_starting_offset
> 4. Remove the log of dev_info.
> ---
>  drivers/usb/dwc3/core.c | 11 +++++++++++
>  drivers/usb/dwc3/core.h |  2 ++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 0beaab932e7d..278cd1c33841 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,rtd-dwc3")) {

Is your platform already released or is it still under development? Just
curious since the compatible string isn't fixed. Is it going to be
changed in the future?

> +			dwc_res.start -= DWC3_GLOBALS_REGS_START;
> +			dwc_res.start += DWC3_RTK_RTD_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..1968638f29ed 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 DWC3_RTK_RTD_GLOBALS_REGS_START	0x8100
> +
>  /* Global Registers */
>  #define DWC3_GSBUSCFG0		0xc100
>  #define DWC3_GSBUSCFG1		0xc104
> -- 
> 2.34.1
> 

Thanks,
Thinh