[v2,2/2] PCI: uniphier: Add UniPhier PCIe endpoint controller support

diff --git a/MAINTAINERS b/MAINTAINERS
index 9ae5237..4a2b634 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13116,7 +13116,7 @@  M:	Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
 L:	linux-pci@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/pci/uniphier-pcie*.txt
-F:	drivers/pci/controller/dwc/pcie-uniphier.c
+F:	drivers/pci/controller/dwc/pcie-uniphier*.c
 
 PCIE DRIVER FOR ST SPEAR13XX
 M:	Pratyush Anand <pratyush.anand@gmail.com>
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 169cde5..4dd5ba9 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -282,15 +282,24 @@  config PCIE_TEGRA194_EP
 	  selected. This uses the DesignWare core.
 
 config PCIE_UNIPHIER
-	bool "Socionext UniPhier PCIe controllers"
+	bool "Socionext UniPhier PCIe host controllers"
 	depends on ARCH_UNIPHIER || COMPILE_TEST
 	depends on OF && HAS_IOMEM
 	depends on PCI_MSI_IRQ_DOMAIN
 	select PCIE_DW_HOST
 	help
-	  Say Y here if you want PCIe controller support on UniPhier SoCs.
+	  Say Y here if you want PCIe host controller support on UniPhier SoCs.
 	  This driver supports LD20 and PXs3 SoCs.
 
+config PCIE_UNIPHIER_EP
+	bool "Socionext UniPhier PCIe endpoint controllers"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	select PCIE_DW_EP
+	help
+	  Say Y here if you want PCIe endpoint controller support on
+	  UniPhier SoCs. This driver supports Pro5 SoC.
+
 config PCIE_AL
 	bool "Amazon Annapurna Labs PCIe controller"
 	depends on OF && (ARM64 || COMPILE_TEST)
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index 8a637cf..a751553 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -19,6 +19,7 @@  obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
 obj-$(CONFIG_PCI_MESON) += pci-meson.o
 obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
 obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
+obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.
diff --git a/drivers/pci/controller/dwc/pcie-uniphier-ep.c b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
new file mode 100644
index 0000000..edffee2
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-uniphier-ep.c
@@ -0,0 +1,405 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe endpoint controller driver for UniPhier SoCs
+ * Copyright 2018 Socionext Inc.
+ * Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+/* Link Glue registers */
+#define PCL_RSTCTRL0			0x0010
+#define PCL_RSTCTRL_AXI_REG		BIT(3)
+#define PCL_RSTCTRL_AXI_SLAVE		BIT(2)
+#define PCL_RSTCTRL_AXI_MASTER		BIT(1)
+#define PCL_RSTCTRL_PIPE3		BIT(0)
+
+#define PCL_RSTCTRL1			0x0020
+#define PCL_RSTCTRL_PERST		BIT(0)
+
+#define PCL_RSTCTRL2			0x0024
+#define PCL_RSTCTRL_PHY_RESET		BIT(0)
+
+#define PCL_MODE			0x8000
+#define PCL_MODE_REGEN			BIT(8)
+#define PCL_MODE_REGVAL			BIT(0)
+
+#define PCL_APP_CLK_CTRL		0x8004
+#define PCL_APP_CLK_REQ			BIT(0)
+
+#define PCL_APP_READY_CTRL		0x8008
+#define PCL_APP_LTSSM_ENABLE		BIT(0)
+
+#define PCL_APP_MSI0			0x8040
+#define PCL_APP_VEN_MSI_TC_MASK		GENMASK(10, 8)
+#define PCL_APP_VEN_MSI_VECTOR_MASK	GENMASK(4, 0)
+
+#define PCL_APP_MSI1			0x8044
+#define PCL_APP_MSI_REQ			BIT(0)
+
+#define PCL_APP_INTX			0x8074
+#define PCL_APP_INTX_SYS_INT		BIT(0)
+
+/* assertion time of intx in usec */
+#define PCL_INTX_WIDTH_USEC		30
+
+struct uniphier_pcie_ep_priv {
+	void __iomem *base;
+	struct dw_pcie pci;
+	struct clk *clk, *clk_gio;
+	struct reset_control *rst, *rst_gio;
+	struct phy *phy;
+	const struct uniphier_pcie_ep_soc_data *data;
+};
+
+struct uniphier_pcie_ep_soc_data {
+	bool is_legacy;
+	const struct pci_epc_features features;
+};
+
+#define to_uniphier_pcie(x)	dev_get_drvdata((x)->dev)
+
+static void uniphier_pcie_ltssm_enable(struct uniphier_pcie_ep_priv *priv,
+				       bool enable)
+{
+	u32 val;
+
+	val = readl(priv->base + PCL_APP_READY_CTRL);
+	if (enable)
+		val |= PCL_APP_LTSSM_ENABLE;
+	else
+		val &= ~PCL_APP_LTSSM_ENABLE;
+	writel(val, priv->base + PCL_APP_READY_CTRL);
+}
+
+static void uniphier_pcie_phy_reset(struct uniphier_pcie_ep_priv *priv,
+				    bool assert)
+{
+	u32 val;
+
+	val = readl(priv->base + PCL_RSTCTRL2);
+	if (assert)
+		val |= PCL_RSTCTRL_PHY_RESET;
+	else
+		val &= ~PCL_RSTCTRL_PHY_RESET;
+	writel(val, priv->base + PCL_RSTCTRL2);
+}
+
+static void uniphier_pcie_init_ep(struct uniphier_pcie_ep_priv *priv)
+{
+	u32 val;
+
+	/* set EP mode */
+	val = readl(priv->base + PCL_MODE);
+	val |= PCL_MODE_REGEN | PCL_MODE_REGVAL;
+	writel(val, priv->base + PCL_MODE);
+
+	/* clock request */
+	val = readl(priv->base + PCL_APP_CLK_CTRL);
+	val &= ~PCL_APP_CLK_REQ;
+	writel(val, priv->base + PCL_APP_CLK_CTRL);
+
+	/* deassert PIPE3 and AXI reset */
+	val = readl(priv->base + PCL_RSTCTRL0);
+	val |= PCL_RSTCTRL_AXI_REG | PCL_RSTCTRL_AXI_SLAVE
+		| PCL_RSTCTRL_AXI_MASTER | PCL_RSTCTRL_PIPE3;
+	writel(val, priv->base + PCL_RSTCTRL0);
+
+	uniphier_pcie_ltssm_enable(priv, false);
+
+	msleep(100);
+}
+
+static int uniphier_pcie_start_link(struct dw_pcie *pci)
+{
+	struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+
+	uniphier_pcie_ltssm_enable(priv, true);
+
+	return 0;
+}
+
+static void uniphier_pcie_stop_link(struct dw_pcie *pci)
+{
+	struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+
+	uniphier_pcie_ltssm_enable(priv, false);
+}
+
+static void uniphier_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	enum pci_barno bar;
+
+	for (bar = BAR_0; bar <= BAR_5; bar++)
+		dw_pcie_ep_reset_bar(pci, bar);
+}
+
+static int uniphier_pcie_ep_raise_legacy_irq(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+	u32 val;
+
+	/* assert INTx */
+	val = readl(priv->base + PCL_APP_INTX);
+	val |= PCL_APP_INTX_SYS_INT;
+	writel(val, priv->base + PCL_APP_INTX);
+
+	udelay(PCL_INTX_WIDTH_USEC);
+
+	/* deassert INTx */
+	val = readl(priv->base + PCL_APP_INTX);
+	val &= ~PCL_APP_INTX_SYS_INT;
+	writel(val, priv->base + PCL_APP_INTX);
+
+	return 0;
+}
+
+static int uniphier_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep,
+					  u8 func_no, u16 interrupt_num)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+	u32 val;
+
+	val = FIELD_PREP(PCL_APP_VEN_MSI_TC_MASK, func_no)
+		| FIELD_PREP(PCL_APP_VEN_MSI_VECTOR_MASK, interrupt_num - 1);
+	writel(val, priv->base + PCL_APP_MSI0);
+
+	val = readl(priv->base + PCL_APP_MSI1);
+	val |= PCL_APP_MSI_REQ;
+	writel(val, priv->base + PCL_APP_MSI1);
+
+	return 0;
+}
+
+static int uniphier_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
+				      enum pci_epc_irq_type type,
+				      u16 interrupt_num)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	switch (type) {
+	case PCI_EPC_IRQ_LEGACY:
+		return uniphier_pcie_ep_raise_legacy_irq(ep);
+	case PCI_EPC_IRQ_MSI:
+		return uniphier_pcie_ep_raise_msi_irq(ep, func_no,
+						      interrupt_num);
+	default:
+		dev_err(pci->dev, "UNKNOWN IRQ type (%d)\n", type);
+	}
+
+	return 0;
+}
+
+static const struct pci_epc_features*
+uniphier_pcie_get_features(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	struct uniphier_pcie_ep_priv *priv = to_uniphier_pcie(pci);
+
+	return &priv->data->features;
+}
+
+static const struct dw_pcie_ep_ops uniphier_pcie_ep_ops = {
+	.ep_init = uniphier_pcie_ep_init,
+	.raise_irq = uniphier_pcie_ep_raise_irq,
+	.get_features = uniphier_pcie_get_features,
+};
+
+static int uniphier_add_pcie_ep(struct uniphier_pcie_ep_priv *priv,
+				struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &priv->pci;
+	struct dw_pcie_ep *ep = &pci->ep;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	int ret;
+
+	ep->ops = &uniphier_pcie_ep_ops;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi2");
+	pci->dbi_base2 = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pci->dbi_base2))
+		return PTR_ERR(pci->dbi_base2);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
+	if (!res)
+		return -EINVAL;
+
+	ep->phys_base = res->start;
+	ep->addr_size = resource_size(res);
+
+	ret = dw_pcie_ep_init(ep);
+	if (ret) {
+		dev_err(dev, "Failed to initialize endpoint (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int uniphier_pcie_ep_enable(struct uniphier_pcie_ep_priv *priv)
+{
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(priv->clk_gio);
+	if (ret)
+		goto out_clk_disable;
+
+	ret = reset_control_deassert(priv->rst);
+	if (ret)
+		goto out_clk_gio_disable;
+
+	ret = reset_control_deassert(priv->rst_gio);
+	if (ret)
+		goto out_rst_assert;
+
+	uniphier_pcie_init_ep(priv);
+
+	if (priv->data->is_legacy)
+		uniphier_pcie_phy_reset(priv, true);
+
+	ret = phy_init(priv->phy);
+	if (ret)
+		goto out_rst_gio_assert;
+
+	if (priv->data->is_legacy)
+		uniphier_pcie_phy_reset(priv, false);
+
+	return 0;
+
+out_rst_gio_assert:
+	reset_control_assert(priv->rst_gio);
+out_rst_assert:
+	reset_control_assert(priv->rst);
+out_clk_gio_disable:
+	clk_disable_unprepare(priv->clk_gio);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.start_link = uniphier_pcie_start_link,
+	.stop_link = uniphier_pcie_stop_link,
+};
+
+static int uniphier_pcie_ep_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_pcie_ep_priv *priv;
+	struct resource *res;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->data = of_device_get_match_data(dev);
+	if (WARN_ON(!priv->data))
+		return -EINVAL;
+
+	priv->pci.dev = dev;
+	priv->pci.ops = &dw_pcie_ops;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	priv->pci.dbi_base = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(priv->pci.dbi_base))
+		return PTR_ERR(priv->pci.dbi_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "link");
+	priv->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	if (priv->data->is_legacy) {
+		priv->clk_gio = devm_clk_get(dev, "gio");
+		if (IS_ERR(priv->clk))
+			return PTR_ERR(priv->clk);
+
+		priv->rst_gio =
+			devm_reset_control_get_shared(dev, "gio");
+		if (IS_ERR(priv->rst_gio))
+			return PTR_ERR(priv->rst_gio);
+
+		priv->clk = devm_clk_get(dev, "link");
+		if (IS_ERR(priv->clk))
+			return PTR_ERR(priv->clk);
+
+		priv->rst =
+			devm_reset_control_get_shared(dev, "link");
+		if (IS_ERR(priv->rst))
+			return PTR_ERR(priv->rst);
+	} else {
+		priv->clk = devm_clk_get(dev, NULL);
+		if (IS_ERR(priv->clk))
+			return PTR_ERR(priv->clk);
+
+		priv->rst = devm_reset_control_get_shared(dev, NULL);
+		if (IS_ERR(priv->rst))
+			return PTR_ERR(priv->rst);
+	}
+
+	priv->phy = devm_phy_optional_get(dev, "pcie-phy");
+	if (IS_ERR(priv->phy)) {
+		ret = PTR_ERR(priv->phy);
+		dev_err(dev, "Failed to get phy (%d)\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = uniphier_pcie_ep_enable(priv);
+	if (ret)
+		return ret;
+
+	return uniphier_add_pcie_ep(priv, pdev);
+}
+
+static const struct uniphier_pcie_ep_soc_data uniphier_pro5_data = {
+	.is_legacy = true,
+	.features = {
+		.linkup_notifier = false,
+		.msi_capable = true,
+		.msix_capable = false,
+		.align = 1 << 16,
+		.bar_fixed_64bit = BIT(BAR_0) | BIT(BAR_2) | BIT(BAR_4),
+		.reserved_bar =  BIT(BAR_4),
+	},
+};
+
+static const struct of_device_id uniphier_pcie_ep_match[] = {
+	{
+		.compatible = "socionext,uniphier-pro5-pcie-ep",
+		.data = &uniphier_pro5_data,
+	},
+	{ /* sentinel */ },
+};
+
+static struct platform_driver uniphier_pcie_ep_driver = {
+	.probe  = uniphier_pcie_ep_probe,
+	.driver = {
+		.name = "uniphier-pcie-ep",
+		.of_match_table = uniphier_pcie_ep_match,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(uniphier_pcie_ep_driver);