[PATCH v3 04/15] PCI: aardvark: Add PHY support

[Miquel Raynal]

The IP needs its PHY to be properly configured to work. While the PHY
is usually already configured by the bootloader, we will need this
feature when adding S2RAM support. Take care of registering and
configuring the PHY from the driver itself.

Suggested-by: Grzegorz Jaszczyk <jaz@xxxxxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
 drivers/pci/controller/pci-aardvark.c | 62 +++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index b1b8897d2d28..27ec79defa57 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -17,6 +17,7 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
+#include <linux/phy/phy.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
 
@@ -203,6 +204,7 @@ struct advk_pcie {
 	u16 msi_msg;
 	int root_bus_nr;
 	struct pci_bridge_emul bridge;
+	struct phy *phy;
 };
 
 static inline void advk_writel(struct advk_pcie *pcie, u32 val, u64 reg)
@@ -998,6 +1000,62 @@ static int advk_pcie_setup_clk(struct advk_pcie *pcie)
 	return ret;
 }
 
+static void __maybe_unused advk_pcie_disable_phy(struct advk_pcie *pcie)
+{
+	phy_power_off(pcie->phy);
+	phy_exit(pcie->phy);
+}
+
+static int advk_pcie_enable_phy(struct advk_pcie *pcie)
+{
+	int ret;
+
+	if (!pcie->phy)
+		return 0;
+
+	ret = phy_init(pcie->phy);
+	if (ret)
+		return ret;
+
+	ret = phy_set_mode(pcie->phy, PHY_MODE_PCIE);
+	if (ret) {
+		phy_exit(pcie->phy);
+		return ret;
+	}
+
+	ret = phy_power_on(pcie->phy);
+	if (ret) {
+		phy_exit(pcie->phy);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int advk_pcie_setup_phy(struct advk_pcie *pcie)
+{
+	struct device *dev = &pcie->pdev->dev;
+	struct device_node *node = dev->of_node;
+	int ret = 0;
+
+	pcie->phy = devm_of_phy_get(dev, node, NULL);
+	if (IS_ERR(pcie->phy) && (PTR_ERR(pcie->phy) == -EPROBE_DEFER))
+		return PTR_ERR(pcie->phy);
+
+	/* Old bindings miss the PHY handle */
+	if (IS_ERR(pcie->phy)) {
+		dev_warn(dev, "PHY unavailable (%ld)\n", PTR_ERR(pcie->phy));
+		pcie->phy = NULL;
+		return 0;
+	}
+
+	ret = advk_pcie_enable_phy(pcie);
+	if (ret)
+		dev_err(dev, "Failed to initialize PHY (%d)\n", ret);
+
+	return ret;
+}
+
 static int advk_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1037,6 +1095,10 @@ static int advk_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = advk_pcie_setup_phy(pcie);
+	if (ret)
+		return ret;
+
 	advk_pcie_setup_hw(pcie);
 
 	advk_sw_pci_bridge_init(pcie);
-- 
2.19.1