USB: dwc3: refactor clock lookups

The probe callback has become unwieldy so break out the clock lookups
into a new helper function to improve readability.
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230404072524.19014-11-johan+linaro@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/core.c

@@ -1704,6 +1704,64 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
 	return edev;
 }
 
+static int dwc3_get_clocks(struct dwc3 *dwc)
+{
+	struct device *dev = dwc->dev;
+
+	if (!dev->of_node)
+		return 0;
+
+	/*
+	 * Clocks are optional, but new DT platforms should support all clocks
+	 * as required by the DT-binding.
+	 * Some devices have different clock names in legacy device trees,
+	 * check for them to retain backwards compatibility.
+	 */
+	dwc->bus_clk = devm_clk_get_optional(dev, "bus_early");
+	if (IS_ERR(dwc->bus_clk)) {
+		return dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
+				"could not get bus clock\n");
+	}
+
+	if (dwc->bus_clk == NULL) {
+		dwc->bus_clk = devm_clk_get_optional(dev, "bus_clk");
+		if (IS_ERR(dwc->bus_clk)) {
+			return dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
+					"could not get bus clock\n");
+		}
+	}
+
+	dwc->ref_clk = devm_clk_get_optional(dev, "ref");
+	if (IS_ERR(dwc->ref_clk)) {
+		return dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
+				"could not get ref clock\n");
+	}
+
+	if (dwc->ref_clk == NULL) {
+		dwc->ref_clk = devm_clk_get_optional(dev, "ref_clk");
+		if (IS_ERR(dwc->ref_clk)) {
+			return dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
+					"could not get ref clock\n");
+		}
+	}
+
+	dwc->susp_clk = devm_clk_get_optional(dev, "suspend");
+	if (IS_ERR(dwc->susp_clk)) {
+		return dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
+				"could not get suspend clock\n");
+	}
+
+	if (dwc->susp_clk == NULL) {
+		dwc->susp_clk = devm_clk_get_optional(dev, "suspend_clk");
+		if (IS_ERR(dwc->susp_clk)) {
+			return dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
+					"could not get suspend clock\n");
+		}
+	}
+
+	return 0;
+}
+
 static int dwc3_probe(struct platform_device *pdev)
 {
 	struct device		*dev = &pdev->dev;
@@ -1754,61 +1812,9 @@ static int dwc3_probe(struct platform_device *pdev)
 		goto err_put_psy;
 	}
 
-	if (dev->of_node) {
-		/*
-		 * Clocks are optional, but new DT platforms should support all
-		 * clocks as required by the DT-binding.
-		 * Some devices have different clock names in legacy device trees,
-		 * check for them to retain backwards compatibility.
-		 */
-		dwc->bus_clk = devm_clk_get_optional(dev, "bus_early");
-		if (IS_ERR(dwc->bus_clk)) {
-			ret = dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
-					    "could not get bus clock\n");
-			goto err_put_psy;
-		}
-
-		if (dwc->bus_clk == NULL) {
-			dwc->bus_clk = devm_clk_get_optional(dev, "bus_clk");
-			if (IS_ERR(dwc->bus_clk)) {
-				ret = dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
-						    "could not get bus clock\n");
-				goto err_put_psy;
-			}
-		}
-
-		dwc->ref_clk = devm_clk_get_optional(dev, "ref");
-		if (IS_ERR(dwc->ref_clk)) {
-			ret = dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
-					    "could not get ref clock\n");
-			goto err_put_psy;
-		}
-
-		if (dwc->ref_clk == NULL) {
-			dwc->ref_clk = devm_clk_get_optional(dev, "ref_clk");
-			if (IS_ERR(dwc->ref_clk)) {
-				ret = dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
-						    "could not get ref clock\n");
-				goto err_put_psy;
-			}
-		}
-
-		dwc->susp_clk = devm_clk_get_optional(dev, "suspend");
-		if (IS_ERR(dwc->susp_clk)) {
-			ret = dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
-					    "could not get suspend clock\n");
-			goto err_put_psy;
-		}
-
-		if (dwc->susp_clk == NULL) {
-			dwc->susp_clk = devm_clk_get_optional(dev, "suspend_clk");
-			if (IS_ERR(dwc->susp_clk)) {
-				ret = dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
-						    "could not get suspend clock\n");
-				goto err_put_psy;
-			}
-		}
-	}
+	ret = dwc3_get_clocks(dwc);
+	if (ret)
+		goto err_put_psy;
 
 	ret = reset_control_deassert(dwc->reset);
 	if (ret)