Re: [PATCH v4 2/4] usb: dwc3: Add software-managed properties for flattened model

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

On Fri, Sep 26, 2025, Frank Li via B4 Relay wrote:
> From: Frank Li <Frank.Li@nxp.com>
> 
> Add software-managed properties for the flattened model, which does not
> need to use device tree properties to pass down information to the
> common DWC3 core.
> 
> Add 'properties' in dwc3_probe_data and set default values for existing
> users (dwc3-qcom, dwc3-generic-plat).
> 
> No functional changes.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
> change in v4
> - new patch
> ---
>  drivers/usb/dwc3/core.c              | 12 ++++++++++--
>  drivers/usb/dwc3/dwc3-generic-plat.c |  1 +
>  drivers/usb/dwc3/dwc3-qcom.c         |  1 +
>  drivers/usb/dwc3/glue.h              | 14 ++++++++++++++
>  4 files changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 805cd22f42e0961252b0371da9b16cc804e49342..35f9c566358886c106d360dea84f2e6f1ac19688 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1668,7 +1668,8 @@ static void dwc3_core_exit_mode(struct dwc3 *dwc)
>  	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE, true);
>  }
>  
> -static void dwc3_get_software_properties(struct dwc3 *dwc)
> +static void dwc3_get_software_properties(struct dwc3 *dwc,
> +					 const struct dwc3_properties *properties)
>  {
>  	struct device *tmpdev;
>  	u16 gsbuscfg0_reqinfo;
> @@ -1676,6 +1677,12 @@ static void dwc3_get_software_properties(struct dwc3 *dwc)
>  
>  	dwc->gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED;
>  
> +	if (properties->gsbuscfg0_reqinfo !=
> +	    DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED) {
> +		dwc->gsbuscfg0_reqinfo = properties->gsbuscfg0_reqinfo;
> +		return;

Self-note: perhaps in the future we can fill out and consolidate all the
dwc3 property fields under dwc->properties, and we can directly copy the
entire struct to dwc->properties.

> +	}
> +
>  	/*
>  	 * Iterate over all parent nodes for finding swnode properties
>  	 * and non-DT (non-ABI) properties.
> @@ -2208,7 +2215,7 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
>  
>  	dwc3_get_properties(dwc);
>  
> -	dwc3_get_software_properties(dwc);
> +	dwc3_get_software_properties(dwc, &data->properties);
>  
>  	dwc->usb_psy = dwc3_get_usb_power_supply(dwc);
>  	if (IS_ERR(dwc->usb_psy))
> @@ -2358,6 +2365,7 @@ static int dwc3_probe(struct platform_device *pdev)
>  
>  	probe_data.dwc = dwc;
>  	probe_data.res = res;
> +	probe_data.properties = DWC3_DEFAULT_PROPERTIES;
>  
>  	return dwc3_core_probe(&probe_data);
>  }
> diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
> index d96b20570002dc619ea813f4d6a8013636a0f346..af95a527dcc27a7a14d38dcc887f74a888ed91e6 100644
> --- a/drivers/usb/dwc3/dwc3-generic-plat.c
> +++ b/drivers/usb/dwc3/dwc3-generic-plat.c
> @@ -75,6 +75,7 @@ static int dwc3_generic_probe(struct platform_device *pdev)
>  	probe_data.dwc = &dwc3g->dwc;
>  	probe_data.res = res;
>  	probe_data.ignore_clocks_and_resets = true;
> +	probe_data.properties = DWC3_DEFAULT_PROPERTIES;
>  	ret = dwc3_core_probe(&probe_data);
>  	if (ret)
>  		return dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index ded2ca86670c0bd7ceadd3cba3fa5ecf9e7e02b5..9ac75547820d978b4a32e570e5f59a2807be68a2 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -704,6 +704,7 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	probe_data.dwc = &qcom->dwc;
>  	probe_data.res = &res;
>  	probe_data.ignore_clocks_and_resets = true;
> +	probe_data.properties = DWC3_DEFAULT_PROPERTIES;
>  	ret = dwc3_core_probe(&probe_data);
>  	if (ret)  {
>  		ret = dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
> diff --git a/drivers/usb/dwc3/glue.h b/drivers/usb/dwc3/glue.h
> index 2efd00e763be4fc51911f32d43054059e61fb43a..300260e11adecb0e5b581bfe2b61c2c6928e874f 100644
> --- a/drivers/usb/dwc3/glue.h
> +++ b/drivers/usb/dwc3/glue.h
> @@ -9,17 +9,31 @@
>  #include <linux/types.h>
>  #include "core.h"
>  
> +/**
> + * dwc3_properties: DWC3 core properties
> + * @gsbuscfg0_reqinfo: Value to be programmed in the GSBUSCFG0.REQINFO field
> + */
> +struct dwc3_properties {
> +	u32 gsbuscfg0_reqinfo;
> +};
> +
> +#define DWC3_DEFAULT_PROPERTIES ((struct dwc3_properties){		\
> +	.gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED,	\
> +	})
> +
>  /**
>   * dwc3_probe_data: Initialization parameters passed to dwc3_core_probe()
>   * @dwc: Reference to dwc3 context structure
>   * @res: resource for the DWC3 core mmio region
>   * @ignore_clocks_and_resets: clocks and resets defined for the device should
>   *		be ignored by the DWC3 core, as they are managed by the glue
> + * @properties: dwc3 software manage propertyies

Minor nit: propertyies -> properties

>   */
>  struct dwc3_probe_data {
>  	struct dwc3 *dwc;
>  	struct resource *res;
>  	bool ignore_clocks_and_resets;
> +	struct dwc3_properties properties;
>  };
>  
>  int dwc3_core_probe(const struct dwc3_probe_data *data);
> 
> -- 
> 2.34.1
> 
> 

Beside the minor nit,

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh