PCI: tegra: Rearrange Tegra PCIe driver functions

Tegra PCIe has register specifications for:

 - AXI to FPCI(AFI) bridge
 - Multiple PCIe root ports
 - PCIe PHY
 - PCIe pad control

Rearrange Tegra PCIe driver functions so that each function programs
the required module only.

- tegra_pcie_enable_controller(): Program AFI module and enable PCIe
  controller
- tegra_pcie_phy_power_on(): Bring up PCIe PHY
- tegra_pcie_apply_pad_settings(): Program PCIe REFCLK pad settings
- tegra_pcie_enable_ports(): Program each root port and bring up PCIe
  link

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>

1 files changed, 30 insertions, 40 deletions

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 85c5e6a1e529..5d93bb32ad44 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -852,7 +852,6 @@ static int tegra_pcie_port_phy_power_off(struct tegra_pcie_port *port)
 static int tegra_pcie_phy_power_on(struct tegra_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
-	const struct tegra_pcie_soc *soc = pcie->soc;
 	struct tegra_pcie_port *port;
 	int err;
 
@@ -878,12 +877,6 @@ static int tegra_pcie_phy_power_on(struct tegra_pcie *pcie)
 		}
 	}
 
-	/* Configure the reference clock driver */
-	pads_writel(pcie, soc->pads_refclk_cfg0, PADS_REFCLK_CFG0);
-
-	if (soc->num_ports > 2)
-		pads_writel(pcie, soc->pads_refclk_cfg1, PADS_REFCLK_CFG1);
-
 	return 0;
 }
 
@@ -918,13 +911,11 @@ static int tegra_pcie_phy_power_off(struct tegra_pcie *pcie)
 	return 0;
 }
 
-static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
+static void tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 {
-	struct device *dev = pcie->dev;
 	const struct tegra_pcie_soc *soc = pcie->soc;
 	struct tegra_pcie_port *port;
 	unsigned long value;
-	int err;
 
 	/* enable PLL power down */
 	if (pcie->phy) {
@@ -958,14 +949,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 		afi_writel(pcie, value, AFI_FUSE);
 	}
 
-	if (soc->program_uphy) {
-		err = tegra_pcie_phy_power_on(pcie);
-		if (err < 0) {
-			dev_err(dev, "failed to power on PHY(s): %d\n", err);
-			return err;
-		}
-	}
-
 	/* take the PCIe interface module out of reset */
 	reset_control_deassert(pcie->pcie_xrst);
 
@@ -989,22 +972,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie)
 
 	/* disable all exceptions */
 	afi_writel(pcie, 0, AFI_FPCI_ERROR_MASKS);
-
-	return 0;
-}
-
-static void tegra_pcie_disable_controller(struct tegra_pcie *pcie)
-{
-	int err;
-
-	reset_control_assert(pcie->pcie_xrst);
-
-	if (pcie->soc->program_uphy) {
-		err = tegra_pcie_phy_power_off(pcie);
-		if (err < 0)
-			dev_err(pcie->dev, "failed to power off PHY(s): %d\n",
-				err);
-	}
 }
 
 static void tegra_pcie_power_off(struct tegra_pcie *pcie)
@@ -1106,6 +1073,17 @@ regulator_disable:
 	return err;
 }
 
+static void tegra_pcie_apply_pad_settings(struct tegra_pcie *pcie)
+{
+	const struct tegra_pcie_soc *soc = pcie->soc;
+
+	/* Configure the reference clock driver */
+	pads_writel(pcie, soc->pads_refclk_cfg0, PADS_REFCLK_CFG0);
+
+	if (soc->num_ports > 2)
+		pads_writel(pcie, soc->pads_refclk_cfg1, PADS_REFCLK_CFG1);
+}
+
 static int tegra_pcie_clocks_get(struct tegra_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
@@ -2501,16 +2479,23 @@ static int __maybe_unused tegra_pcie_pm_suspend(struct device *dev)
 {
 	struct tegra_pcie *pcie = dev_get_drvdata(dev);
 	struct tegra_pcie_port *port;
+	int err;
 
 	list_for_each_entry(port, &pcie->ports, list)
 		tegra_pcie_pme_turnoff(port);
 
 	tegra_pcie_disable_ports(pcie);
 
+	if (pcie->soc->program_uphy) {
+		err = tegra_pcie_phy_power_off(pcie);
+		if (err < 0)
+			dev_err(dev, "failed to power off PHY(s): %d\n", err);
+	}
+
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_disable_msi(pcie);
 
-	tegra_pcie_disable_controller(pcie);
+	reset_control_assert(pcie->pcie_xrst);
 	tegra_pcie_power_off(pcie);
 
 	return 0;
@@ -2526,16 +2511,21 @@ static int __maybe_unused tegra_pcie_pm_resume(struct device *dev)
 		dev_err(dev, "tegra pcie power on fail: %d\n", err);
 		return err;
 	}
-	err = tegra_pcie_enable_controller(pcie);
-	if (err) {
-		dev_err(dev, "tegra pcie controller enable fail: %d\n", err);
-		goto poweroff;
-	}
+	tegra_pcie_enable_controller(pcie);
 	tegra_pcie_setup_translations(pcie);
 
 	if (IS_ENABLED(CONFIG_PCI_MSI))
 		tegra_pcie_enable_msi(pcie);
 
+	if (pcie->soc->program_uphy) {
+		err = tegra_pcie_phy_power_on(pcie);
+		if (err < 0) {
+			dev_err(dev, "failed to power on PHY(s): %d\n", err);
+			goto poweroff;
+		}
+	}
+
+	tegra_pcie_apply_pad_settings(pcie);
 	tegra_pcie_enable_ports(pcie);
 
 	return 0;