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

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

On Thu, Sep 25, 2025, Frank Li wrote:
> On Wed, Sep 24, 2025 at 10:13:36PM +0000, Thinh Nguyen wrote:
> > >
> > > +static const struct dwc3_generic_drvdata spacemit_k1_dwc3 = {
> > > +	.gsbuscfg0 = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED,
> >
> > Why do we need to do this?
> 
> because is 0 valildate setting for cfg0_regqinfo.
> 
> Avoid add new flags like REGINFO_VALDATE in drvdata. dwc3 will use default
> value if reginfo is DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED.
> 
> of cousre, if you like add bool b_usebuscfg0 in drvdata, I am also fine.
> 

Let's avoid the parent-child model to pass the properties as if they
were from device-tree. That was a workaround we had before the new
flattened model.

I'm thinking of something like below. Let me know if this works for you.
Note that this isn't tested:

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index ae140c356295..bf7323a1658e 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1666,7 +1666,8 @@ 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;
@@ -1674,16 +1675,20 @@ static void dwc3_get_software_properties(struct dwc3 *dwc)
 
 	dwc->gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED;
 
-	/*
-	 * Iterate over all parent nodes for finding swnode properties
-	 * and non-DT (non-ABI) properties.
-	 */
-	for (tmpdev = dwc->dev; tmpdev; tmpdev = tmpdev->parent) {
-		ret = device_property_read_u16(tmpdev,
-					       "snps,gsbuscfg0-reqinfo",
-					       &gsbuscfg0_reqinfo);
-		if (!ret)
-			dwc->gsbuscfg0_reqinfo = gsbuscfg0_reqinfo;
+	if (properties->gsbuscfg0_reqinfo != DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED) {
+		dwc->gsbuscfg0_reqinfo = properties->gsbuscfg0_reqinfo;
+	} else {
+		/*
+		 * Iterate over all parent nodes for finding swnode properties
+		 * and non-DT (non-ABI) properties.
+		 */
+		for (tmpdev = dwc->dev; tmpdev; tmpdev = tmpdev->parent) {
+			ret = device_property_read_u16(tmpdev,
+						       "snps,gsbuscfg0-reqinfo",
+						       &gsbuscfg0_reqinfo);
+			if (!ret)
+				dwc->gsbuscfg0_reqinfo = gsbuscfg0_reqinfo;
+		}
 	}
 }
 
@@ -2206,7 +2211,7 @@ 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))
@@ -2356,6 +2361,7 @@ static int dwc3_probe(struct platform_device *pdev)
 
 	probe_data.dwc = dwc;
 	probe_data.res = res;
+	probe_data.properties.gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED;
 
 	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 d96b20570002..b9bf27ed8c05 100644
--- a/drivers/usb/dwc3/dwc3-generic-plat.c
+++ b/drivers/usb/dwc3/dwc3-generic-plat.c
@@ -30,6 +30,7 @@ static void dwc3_generic_reset_control_assert(void *data)
 static int dwc3_generic_probe(struct platform_device *pdev)
 {
 	struct dwc3_probe_data probe_data = {};
+	const struct dwc3_properties *properties;
 	struct device *dev = &pdev->dev;
 	struct dwc3_generic *dwc3g;
 	struct resource *res;
@@ -75,6 +76,13 @@ 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;
+
+	properties = of_device_get_match_data(dev);
+	if (properties)
+		probe_data.properties = *properties;
+	else
+		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");
@@ -145,8 +153,13 @@ static const struct dev_pm_ops dwc3_generic_dev_pm_ops = {
 		       dwc3_generic_runtime_idle)
 };
 
+static const struct dwc3_properties fsl_ls1028_dwc3 = {
+	.gsbuscfg0_reqinfo = 0x2222,
+};
+
 static const struct of_device_id dwc3_generic_of_match[] = {
 	{ .compatible = "spacemit,k1-dwc3", },
+	{ .compatible = "fsl,ls1028a-dwc3", &fsl_ls1028_dwc3},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dwc3_generic_of_match);
diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index ded2ca86670c..9ac75547820d 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 2efd00e763be..7083ab193417 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: <description>
  */
 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);

---

BR,
Thinh