Re: [PATCH v2 2/3] usb: dwc3: dwc3-generic-plat: add layerscape dwc3 support

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

On Tue, Sep 23, 2025, Frank Li wrote:
> Add layerscape dwc3 support by using flatten dwc3 core library. Layerscape
> dwc3 need set software managed property snps,gsbuscfg0-reqinfo as 0x2222
> when dma-coherence set.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/usb/dwc3/dwc3-generic-plat.c | 30 +++++++++++++++++++++++++++++-
>  1 file changed, 29 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
> index d96b20570002dc619ea813f4d6a8013636a0f346..d886b6e557b12edda71203e4f640a9a0a53b4f35 100644
> --- a/drivers/usb/dwc3/dwc3-generic-plat.c
> +++ b/drivers/usb/dwc3/dwc3-generic-plat.c
> @@ -8,10 +8,15 @@
>   */
>  
>  #include <linux/clk.h>
> +#include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  #include <linux/reset.h>
>  #include "glue.h"
>  
> +struct dwc3_generic_drvdata {
> +	u32	gsbuscfg0;

Are we going to overwrite the entire register or just the REQINFO
fields? The "snps,gsbuscfg0-reqinfo" property only updates the reqinfo
of GSBUSCFG0. Perhaps rename this?

> +};
> +
>  struct dwc3_generic {
>  	struct device		*dev;
>  	struct dwc3		dwc;
> @@ -29,6 +34,7 @@ static void dwc3_generic_reset_control_assert(void *data)
>  
>  static int dwc3_generic_probe(struct platform_device *pdev)
>  {
> +	const struct dwc3_generic_drvdata *drvdata;
>  	struct dwc3_probe_data probe_data = {};
>  	struct device *dev = &pdev->dev;
>  	struct dwc3_generic *dwc3g;
> @@ -41,6 +47,8 @@ static int dwc3_generic_probe(struct platform_device *pdev)
>  
>  	dwc3g->dev = dev;
>  
> +	drvdata = of_device_get_match_data(dev);
> +
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	if (!res) {
>  		dev_err(&pdev->dev, "missing memory resource\n");
> @@ -70,6 +78,17 @@ static int dwc3_generic_probe(struct platform_device *pdev)
>  	if (ret < 0)
>  		return dev_err_probe(dev, ret, "failed to get clocks\n");
>  
> +	if (of_dma_is_coherent(pdev->dev.of_node)) {
> +		struct property_entry props[2] = {};
> +
> +		props[0] = PROPERTY_ENTRY_U16("snps,gsbuscfg0-reqinfo", drvdata->gsbuscfg0);
> +
> +		ret = device_create_managed_software_node(dev, props, NULL);
> +		if (ret)
> +			return dev_err_probe(dev, ret,
> +					     "fail create software managed property node\n");
> +	}
> +
>  	dwc3g->num_clocks = ret;
>  	dwc3g->dwc.dev = dev;
>  	probe_data.dwc = &dwc3g->dwc;
> @@ -145,8 +164,17 @@ static const struct dev_pm_ops dwc3_generic_dev_pm_ops = {
>  		       dwc3_generic_runtime_idle)
>  };
>  
> +static const struct dwc3_generic_drvdata spacemit_k1_dwc3 = {
> +	.gsbuscfg0 = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED,

Why do we need to do this?

> +};
> +
> +static const struct dwc3_generic_drvdata fsl_ls1028_dwc3 = {
> +	.gsbuscfg0 = 0x2222,
> +};
> +
>  static const struct of_device_id dwc3_generic_of_match[] = {
> -	{ .compatible = "spacemit,k1-dwc3", },
> +	{ .compatible = "spacemit,k1-dwc3", &spacemit_k1_dwc3},
> +	{ .compatible = "fsl,ls1028a-dwc3", &fsl_ls1028_dwc3},
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, dwc3_generic_of_match);
> 
> -- 
> 2.34.1
> 

Thanks,
Thinh