oxnas: pcie: model shared resource as external pcie-phy driver

Refactor pcie-oxnas to have shared resources in syscon and new pcie-phy
driver. Hopefully this revives PCIe...

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

2 files changed, 164 insertions, 67 deletions

diff --git a/target/linux/oxnas/files/drivers/pci/host/pcie-oxnas.c b/target/linux/oxnas/files/drivers/pci/host/pcie-oxnas.c
index 76e42d13ef..68898c3beb 100644
--- a/target/linux/oxnas/files/drivers/pci/host/pcie-oxnas.c
+++ b/target/linux/oxnas/files/drivers/pci/host/pcie-oxnas.c
@@ -25,6 +25,8 @@
 #include <linux/gpio.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
+#include <linux/phy.h>
+#include <linux/phy/phy.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
 #include <linux/io.h>
@@ -75,23 +77,6 @@ enum {
 	PCIE_OBTRANS = BIT(12),
 };
 
-enum {
-	HCSL_BIAS_ON = BIT(0),
-	HCSL_PCIE_EN = BIT(1),
-	HCSL_PCIEA_EN = BIT(2),
-	HCSL_PCIEB_EN = BIT(3),
-};
-
-enum {
-	/* pcie phy reg offset */
-	PHY_ADDR = 0,
-	PHY_DATA = 4,
-	/* phy data reg bits */
-	READ_EN = BIT(16),
-	WRITE_EN = BIT(17),
-	CAP_DATA = BIT(18),
-};
-
 /* core config registers */
 enum {
 	PCI_CONFIG_VERSION_DEVICEID = 0,
@@ -127,9 +112,6 @@ enum {
 	PCIE_SLAVE_BE_SHIFT	= 22,
 };
 
-#define ADDR_VAL(val)	((val) & 0xFFFF)
-#define DATA_VAL(val)	((val) & 0xFFFF)
-
 #define PCIE_SLAVE_BE(val)	((val) << PCIE_SLAVE_BE_SHIFT)
 #define PCIE_SLAVE_BE_MASK	PCIE_SLAVE_BE(0xF)
 
@@ -146,7 +128,7 @@ struct oxnas_pcie {
 	struct regmap *sys_ctrl;
 	unsigned int outbound_offset;
 	unsigned int pcie_ctrl_offset;
-
+	struct phy *phy;
 	int haslink;
 	struct platform_device *pdev;
 	struct resource io;
@@ -406,52 +388,11 @@ static void oxnas_pcie_enable(struct device *dev, struct oxnas_pcie *pcie)
 	pci_common_init_dev(dev, &hw);
 }
 
-void oxnas_pcie_init_shared_hw(struct platform_device *pdev,
-			       void __iomem *phybase,
-			       struct regmap *sys_ctrl)
-{
-	struct reset_control *rstc;
-	int ret;
-
-	/* generate clocks from HCSL buffers, shared parts */
-	regmap_write(sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, HCSL_BIAS_ON|HCSL_PCIE_EN);
-
-	/* Ensure PCIe PHY is properly reset */
-	rstc = reset_control_get(&pdev->dev, "phy");
-	if (IS_ERR(rstc)) {
-		ret = PTR_ERR(rstc);
-	} else {
-		ret = reset_control_reset(rstc);
-		reset_control_put(rstc);
-	}
-
-	if (ret) {
-		dev_err(&pdev->dev, "phy reset failed %d\n", ret);
-		return;
-	}
-
-	/* Enable PCIe Pre-Emphasis: What these value means? */
-	writel(ADDR_VAL(0x0014), phybase + PHY_ADDR);
-	writel(DATA_VAL(0xce10) | CAP_DATA, phybase + PHY_DATA);
-	writel(DATA_VAL(0xce10) | WRITE_EN, phybase + PHY_DATA);
-
-	writel(ADDR_VAL(0x2004), phybase + PHY_ADDR);
-	writel(DATA_VAL(0x82c7) | CAP_DATA, phybase + PHY_DATA);
-	writel(DATA_VAL(0x82c7) | WRITE_EN, phybase + PHY_DATA);
-}
-
-static int oxnas_pcie_shared_init(struct platform_device *pdev, struct regmap *sys_ctrl)
+static int oxnas_pcie_shared_init(struct platform_device *pdev, struct oxnas_pcie *pcie)
 {
 	if (++pcie_shared.refcount == 1) {
-		/* we are the first */
-		struct device_node *np = pdev->dev.of_node;
-		void __iomem *phy = of_iomap(np, 2);
-		if (!phy) {
-			--pcie_shared.refcount;
-			return -ENOMEM;
-		}
-		oxnas_pcie_init_shared_hw(pdev, phy, sys_ctrl);
-		iounmap(phy);
+		phy_init(pcie->phy);
+		phy_power_on(pcie->phy);
 		return 0;
 	} else {
 		return 0;
@@ -478,7 +419,6 @@ oxnas_pcie_map_registers(struct platform_device *pdev,
 	u32 outbound_ctrl_offset;
 	u32 pcie_ctrl_offset;
 
-	/* 2 is reserved for shared phy */
 	ret = of_address_to_resource(np, 0, &regs);
 	if (ret)
 		return -EINVAL;
@@ -493,6 +433,12 @@ oxnas_pcie_map_registers(struct platform_device *pdev,
 	if (!pcie->inbound)
 		return -ENOMEM;
 
+	pcie->phy = devm_of_phy_get(&pdev->dev, np, NULL);
+	if (IS_ERR(pcie->phy)) {
+		if (PTR_ERR(pcie->phy) == -EPROBE_DEFER)
+			return PTR_ERR(pcie->phy);
+		pcie->phy = NULL;
+	}
 
 	if (of_property_read_u32(np, "plxtech,pcie-outbound-offset",
 				 &outbound_ctrl_offset))
@@ -589,6 +535,7 @@ static void oxnas_pcie_init_hw(struct platform_device *pdev,
 		mdelay(100);
 	}
 
+	/* ToDo: use phy power-on port... */
 	regmap_update_bits(pcie->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET,
 	                   BIT(pcie->hcsl_en), BIT(pcie->hcsl_en));
 
@@ -664,7 +611,7 @@ static int oxnas_pcie_probe(struct platform_device *pdev)
 		goto err_free_gpio;
 	}
 
-	ret = oxnas_pcie_shared_init(pdev, pcie->sys_ctrl);
+	ret = oxnas_pcie_shared_init(pdev, pcie);
 	if (ret)
 		goto err_free_gpio;
 
diff --git a/target/linux/oxnas/files/drivers/phy/phy-oxnas-pcie.c b/target/linux/oxnas/files/drivers/phy/phy-oxnas-pcie.c
new file mode 100644
index 0000000000..676a5f9332
--- /dev/null
+++ b/target/linux/oxnas/files/drivers/phy/phy-oxnas-pcie.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Daniel Golle <daniel@makrotopia.org>
+ *
+ */
+
+#include <dt-bindings/phy/phy.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#define ADDR_VAL(val)	((val) & 0xFFFF)
+#define DATA_VAL(val)	((val) & 0xFFFF)
+
+#define SYS_CTRL_HCSL_CTRL_REGOFFSET	0x114
+
+enum {
+	HCSL_BIAS_ON = BIT(0),
+	HCSL_PCIE_EN = BIT(1),
+	HCSL_PCIEA_EN = BIT(2),
+	HCSL_PCIEB_EN = BIT(3),
+};
+
+enum {
+	/* pcie phy reg offset */
+	PHY_ADDR = 0,
+	PHY_DATA = 4,
+	/* phy data reg bits */
+	READ_EN = BIT(16),
+	WRITE_EN = BIT(17),
+	CAP_DATA = BIT(18),
+};
+
+struct oxnas_pcie_phy {
+	struct device *dev;
+	void __iomem *membase;
+	const struct phy_ops *ops;
+	struct regmap *sys_ctrl;
+};
+
+static int oxnas_pcie_phy_init(struct phy *phy)
+{
+	struct oxnas_pcie_phy *pciephy = phy_get_drvdata(phy);
+	struct reset_control *rstc;
+	int ret;
+
+	/* generate clocks from HCSL buffers, shared parts */
+	regmap_write(pciephy->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, HCSL_BIAS_ON|HCSL_PCIE_EN);
+
+	/* Ensure PCIe PHY is properly reset */
+	rstc = reset_control_get(pciephy->dev, "phy");
+	if (IS_ERR(rstc)) {
+		ret = PTR_ERR(rstc);
+	} else {
+		ret = reset_control_reset(rstc);
+		reset_control_put(rstc);
+	}
+
+	if (ret) {
+		dev_err(pciephy->dev, "phy reset failed %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int oxnas_pcie_phy_power_on(struct phy *phy)
+{
+	struct oxnas_pcie_phy *pciephy = phy_get_drvdata(phy);
+
+	/* Enable PCIe Pre-Emphasis: What these value means? */
+	writel(ADDR_VAL(0x0014), pciephy->membase + PHY_ADDR);
+	writel(DATA_VAL(0xce10) | CAP_DATA, pciephy->membase + PHY_DATA);
+	writel(DATA_VAL(0xce10) | WRITE_EN, pciephy->membase + PHY_DATA);
+
+	writel(ADDR_VAL(0x2004), pciephy->membase + PHY_ADDR);
+	writel(DATA_VAL(0x82c7) | CAP_DATA, pciephy->membase + PHY_DATA);
+	writel(DATA_VAL(0x82c7) | WRITE_EN, pciephy->membase + PHY_DATA);
+
+	return 0;
+}
+
+static const struct phy_ops ops = {
+	.init           = oxnas_pcie_phy_init,
+	.power_on       = oxnas_pcie_phy_power_on,
+	.owner          = THIS_MODULE,
+};
+
+static int oxnas_pcie_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = pdev->dev.of_node;
+	struct phy *generic_phy;
+	struct phy_provider *phy_provider;
+	struct oxnas_pcie_phy *pciephy;
+	struct regmap *sys_ctrl;
+	void __iomem *membase;
+
+	membase = of_iomap(np, 0);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
+
+	sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl");
+	if (IS_ERR(sys_ctrl)) {
+		dev_err(dev, "Cannot find OX820 SYSCRTL\n");
+		return PTR_ERR(sys_ctrl);
+	}
+
+	pciephy = devm_kzalloc(dev, sizeof(*pciephy), GFP_KERNEL);
+	if (!pciephy)
+		return -ENOMEM;
+
+	pciephy->sys_ctrl = sys_ctrl;
+	pciephy->membase = membase;
+	pciephy->dev = dev;
+	pciephy->ops = &ops;
+
+	generic_phy = devm_phy_create(dev, dev->of_node, pciephy->ops);
+	if (IS_ERR(generic_phy)) {
+		dev_err(dev, "failed to create PHY\n");
+		return PTR_ERR(generic_phy);
+	}
+
+	phy_set_drvdata(generic_phy, pciephy);
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id oxnas_pcie_phy_id_table[] = {
+	{ .compatible = "oxsemi,ox820-pcie-phy" },
+	{ },
+};
+
+static struct platform_driver oxnas_pcie_phy_driver = {
+	.probe		= oxnas_pcie_phy_probe,
+	.driver		= {
+		.name		= "ox820-pcie-phy",
+		.of_match_table	= oxnas_pcie_phy_id_table,
+	},
+};
+
+builtin_platform_driver(oxnas_pcie_phy_driver);