Re: [PATCH v2 2/4] usb: dwc3: xilinx: Introduce dwc3_xlnx_config for per-platform data

[Thinh Nguyen]

On Tue, Mar 31, 2026, Radhey Shyam Pandey wrote:
> Replace the direct pltfm_init function pointer in struct dwc3_xlnx with
> a const pointer to a new struct dwc3_xlnx_config. This groups
> per-platform configuration in one place and allows future patches to add
> platform-specific fields (e.g. tx_deemph) without growing dwc3_xlnx.
> 
> While at it, switch from of_match_node() to device_get_match_data() to
> simplify the match data lookup.
> 
> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxx>
> ---
> Changes for v2:
> - New patch, split from "Add Versal2 MMI USB 3.2 controller support".
> - Use device_get_match_data() instead of of_match_node().
> ---
>  drivers/usb/dwc3/dwc3-xilinx.c | 28 ++++++++++++++++++++--------
>  1 file changed, 20 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
> index f41b0da5e89d..bb59b56726e7 100644
> --- a/drivers/usb/dwc3/dwc3-xilinx.c
> +++ b/drivers/usb/dwc3/dwc3-xilinx.c
> @@ -12,6 +12,7 @@
>  #include <linux/clk.h>
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
> +#include <linux/property.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/of_platform.h>
> @@ -41,12 +42,18 @@
>  #define XLNX_USB_FPD_POWER_PRSNT		0x80
>  #define FPD_POWER_PRSNT_OPTION			BIT(0)
>  
> +struct dwc3_xlnx;
> +
> +struct dwc3_xlnx_config {
> +	int				(*pltfm_init)(struct dwc3_xlnx *data);
> +};
> +
>  struct dwc3_xlnx {
>  	int				num_clocks;
>  	struct clk_bulk_data		*clks;
>  	struct device			*dev;
>  	void __iomem			*regs;
> -	int				(*pltfm_init)(struct dwc3_xlnx *data);
> +	const struct dwc3_xlnx_config	*dwc3_config;
>  	struct phy			*usb3_phy;
>  };
>  
> @@ -241,14 +248,22 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
>  	return ret;
>  }
>  
> +static const struct dwc3_xlnx_config zynqmp_config = {
> +	.pltfm_init = dwc3_xlnx_init_zynqmp,
> +};
> +
> +static const struct dwc3_xlnx_config versal_config = {
> +	.pltfm_init = dwc3_xlnx_init_versal,
> +};
> +
>  static const struct of_device_id dwc3_xlnx_of_match[] = {
>  	{
>  		.compatible = "xlnx,zynqmp-dwc3",
> -		.data = &dwc3_xlnx_init_zynqmp,
> +		.data = &zynqmp_config,
>  	},
>  	{
>  		.compatible = "xlnx,versal-dwc3",
> -		.data = &dwc3_xlnx_init_versal,
> +		.data = &versal_config,
>  	},
>  	{ /* Sentinel */ }
>  };
> @@ -284,7 +299,6 @@ static int dwc3_xlnx_probe(struct platform_device *pdev)
>  	struct dwc3_xlnx		*priv_data;
>  	struct device			*dev = &pdev->dev;
>  	struct device_node		*np = dev->of_node;
> -	const struct of_device_id	*match;
>  	void __iomem			*regs;
>  	int				ret;
>  
> @@ -296,9 +310,7 @@ static int dwc3_xlnx_probe(struct platform_device *pdev)
>  	if (IS_ERR(regs))
>  		return dev_err_probe(dev, PTR_ERR(regs), "failed to map registers\n");
>  
> -	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
> -
> -	priv_data->pltfm_init = match->data;
> +	priv_data->dwc3_config = device_get_match_data(dev);
>  	priv_data->regs = regs;
>  	priv_data->dev = dev;
>  
> @@ -314,7 +326,7 @@ static int dwc3_xlnx_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	ret = priv_data->pltfm_init(priv_data);
> +	ret = priv_data->dwc3_config->pltfm_init(priv_data);

Though this won't hit now, but we should check if dwc3_config exists
before accessing it.

BR,
Thinh

>  	if (ret)
>  		goto err_clk_put;
>  
> -- 
> 2.43.0
>