PCI: imx6: Collect clock enables in imx6_pcie_clk_enable()

Encapsulate the i.MX PCIe clock enable operations into one standalone
function, imx6_pcie_clk_enable().  No functional change intended.

[bhelgaas: split pure code moves into separate patches]
Link: https://lore.kernel.org/r/1657783869-19194-7-git-send-email-hongxing.zhu@nxp.comSigned-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>

drivers/pci/controller/dwc/pci-imx6.c

@@ -600,6 +600,58 @@ static void imx6_pcie_disable_ref_clk(struct imx6_pcie *imx6_pcie)
 	}
 }
 
+static int imx6_pcie_clk_enable(struct imx6_pcie *imx6_pcie)
+{
+	struct dw_pcie *pci = imx6_pcie->pci;
+	struct device *dev = pci->dev;
+	int ret;
+
+	ret = clk_prepare_enable(imx6_pcie->pcie_phy);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie_phy clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(imx6_pcie->pcie_bus);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie_bus clock\n");
+		goto err_pcie_bus;
+	}
+
+	ret = clk_prepare_enable(imx6_pcie->pcie);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie clock\n");
+		goto err_pcie;
+	}
+
+	ret = imx6_pcie_enable_ref_clk(imx6_pcie);
+	if (ret) {
+		dev_err(dev, "unable to enable pcie ref clock\n");
+		goto err_ref_clk;
+	}
+
+	switch (imx6_pcie->drvdata->variant) {
+	case IMX8MM:
+		if (phy_power_on(imx6_pcie->phy))
+			dev_err(dev, "unable to power on PHY\n");
+		break;
+	default:
+		break;
+	}
+	/* allow the clocks to stabilize */
+	usleep_range(200, 500);
+	return 0;
+
+err_ref_clk:
+	clk_disable_unprepare(imx6_pcie->pcie);
+err_pcie:
+	clk_disable_unprepare(imx6_pcie->pcie_bus);
+err_pcie_bus:
+	clk_disable_unprepare(imx6_pcie->pcie_phy);
+
+	return ret;
+}
+
 static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
 {
 	clk_disable_unprepare(imx6_pcie->pcie);
@@ -671,40 +723,11 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 		}
 	}
 
-	ret = clk_prepare_enable(imx6_pcie->pcie_phy);
-	if (ret) {
-		dev_err(dev, "unable to enable pcie_phy clock\n");
-		goto err_pcie_phy;
-	}
-
-	ret = clk_prepare_enable(imx6_pcie->pcie_bus);
-	if (ret) {
-		dev_err(dev, "unable to enable pcie_bus clock\n");
-		goto err_pcie_bus;
-	}
-
-	ret = clk_prepare_enable(imx6_pcie->pcie);
-	if (ret) {
-		dev_err(dev, "unable to enable pcie clock\n");
-		goto err_pcie;
-	}
-
-	ret = imx6_pcie_enable_ref_clk(imx6_pcie);
+	ret = imx6_pcie_clk_enable(imx6_pcie);
 	if (ret) {
-		dev_err(dev, "unable to enable pcie ref clock\n");
-		goto err_ref_clk;
-	}
-
-	switch (imx6_pcie->drvdata->variant) {
-	case IMX8MM:
-		if (phy_power_on(imx6_pcie->phy))
-			dev_err(dev, "unable to power on PHY\n");
-		break;
-	default:
-		break;
+		dev_err(dev, "unable to enable pcie clocks: %d\n", ret);
+		goto err_clks;
 	}
-	/* allow the clocks to stabilize */
-	usleep_range(200, 500);
 
 	switch (imx6_pcie->drvdata->variant) {
 	case IMX8MQ:
@@ -763,13 +786,7 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
 
 	return;
 
-err_ref_clk:
-	clk_disable_unprepare(imx6_pcie->pcie);
-err_pcie:
-	clk_disable_unprepare(imx6_pcie->pcie_bus);
-err_pcie_bus:
-	clk_disable_unprepare(imx6_pcie->pcie_phy);
-err_pcie_phy:
+err_clks:
 	if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
 		ret = regulator_disable(imx6_pcie->vpcie);
 		if (ret)