PCI: tegra: Handle failure cases in tegra_pcie_power_on()

Unroll the PCIe power on sequence if any one of the steps fails in
tegra_pcie_power_on().
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>

drivers/pci/controller/pci-tegra.c

@@ -1052,7 +1052,7 @@ static int tegra_pcie_power_on(struct tegra_pcie *pcie)
 		err = clk_prepare_enable(pcie->pex_clk);
 		if (err) {
 			dev_err(dev, "failed to enable PEX clock: %d\n", err);
-			return err;
+			goto regulator_disable;
 		}
 		reset_control_deassert(pcie->pex_rst);
 	} else {
@@ -1061,7 +1061,7 @@ static int tegra_pcie_power_on(struct tegra_pcie *pcie)
 							pcie->pex_rst);
 		if (err) {
 			dev_err(dev, "powerup sequence failed: %d\n", err);
-			return err;
+			goto regulator_disable;
 		}
 	}
 
@@ -1070,24 +1070,40 @@ static int tegra_pcie_power_on(struct tegra_pcie *pcie)
 	err = clk_prepare_enable(pcie->afi_clk);
 	if (err < 0) {
 		dev_err(dev, "failed to enable AFI clock: %d\n", err);
-		return err;
+		goto powergate;
 	}
 
 	if (soc->has_cml_clk) {
 		err = clk_prepare_enable(pcie->cml_clk);
 		if (err < 0) {
 			dev_err(dev, "failed to enable CML clock: %d\n", err);
-			return err;
+			goto disable_afi_clk;
 		}
 	}
 
 	err = clk_prepare_enable(pcie->pll_e);
 	if (err < 0) {
 		dev_err(dev, "failed to enable PLLE clock: %d\n", err);
-		return err;
+		goto disable_cml_clk;
 	}
 
 	return 0;
+
+disable_cml_clk:
+	if (soc->has_cml_clk)
+		clk_disable_unprepare(pcie->cml_clk);
+disable_afi_clk:
+	clk_disable_unprepare(pcie->afi_clk);
+powergate:
+	reset_control_assert(pcie->afi_rst);
+	reset_control_assert(pcie->pex_rst);
+	clk_disable_unprepare(pcie->pex_clk);
+	if (!dev->pm_domain)
+		tegra_powergate_power_off(TEGRA_POWERGATE_PCIE);
+regulator_disable:
+	regulator_bulk_disable(pcie->num_supplies, pcie->supplies);
+
+	return err;
 }
 
 static int tegra_pcie_clocks_get(struct tegra_pcie *pcie)