This introduces specific glue layer for UniPhier platform to support
PCIe host controller that is based on the Designware PCIe Core, and
this driver supports Root Complex (host) mode.

Signed-off-by: Kunihiko Hayashi <hayashi.kunih...@socionext.com>
---
 drivers/pci/controller/dwc/Kconfig         |   9 +
 drivers/pci/controller/dwc/Makefile        |   1 +
 drivers/pci/controller/dwc/pcie-uniphier.c | 464 +++++++++++++++++++++++++++++
 3 files changed, 474 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-uniphier.c

diff --git a/drivers/pci/controller/dwc/Kconfig 
b/drivers/pci/controller/dwc/Kconfig
index 91b0194..d8fdb02 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -193,4 +193,13 @@ config PCIE_HISI_STB
        help
           Say Y here if you want PCIe controller support on HiSilicon STB SoCs
 
+config PCIE_UNIPHIER
+       bool "Socionext UniPhier PCIe controllers"
+       depends on OF && (ARCH_UNIPHIER || COMPILE_TEST)
+       depends on PCI_MSI_IRQ_DOMAIN
+       select PCIE_DW_HOST
+       help
+         Say Y here if you want PCIe controller support on UniPhier SoCs.
+         This driver supports LD20 and PXs3 SoCs.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile 
b/drivers/pci/controller/dwc/Makefile
index 5d2ce72..cbde733 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
 obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
 obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
 obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
+obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.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.c 
b/drivers/pci/controller/dwc/pcie-uniphier.c
new file mode 100644
index 0000000..13ce02e
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// PCI-express host controller driver for UniPhier SoCs
+// Copyright 2018 Socionext Inc.
+// Author: Kunihiko Hayashi <hayashi.kunih...@socionext.com>
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include "pcie-designware.h"
+
+#define PCL_PINCTRL0                   0x002c
+#define PCL_PERST_PLDN_REGEN           BIT(12)
+#define PCL_PERST_NOE_REGEN            BIT(11)
+#define PCL_PERST_OUT_REGEN            BIT(8)
+#define PCL_PERST_PLDN_REGVAL          BIT(4)
+#define PCL_PERST_NOE_REGVAL           BIT(3)
+#define PCL_PERST_OUT_REGVAL           BIT(0)
+
+#define PCL_PIPEMON                    0x0044
+#define PCL_PCLK_ALIVE                 BIT(15)
+
+#define PCL_APP_READY_CTRL             0x8008
+#define PCL_APP_LTSSM_ENABLE           BIT(0)
+
+#define PCL_APP_PM0                    0x8078
+#define PCL_SYS_AUX_PWR_DET            BIT(8)
+
+#define PCL_RCV_INT                    0x8108
+#define PCL_CFG_BW_MGT_ENABLE          BIT(20)
+#define PCL_CFG_LINK_AUTO_BW_ENABLE    BIT(19)
+#define PCL_CFG_AER_RC_ERR_MSI_ENABLE  BIT(18)
+#define PCL_CFG_PME_MSI_ENABLE         BIT(17)
+#define PCL_CFG_BW_MGT_STATUS          BIT(4)
+#define PCL_CFG_LINK_AUTO_BW_STATUS    BIT(3)
+#define PCL_CFG_AER_RC_ERR_MSI_STATUS  BIT(2)
+#define PCL_CFG_PME_MSI_STATUS         BIT(1)
+#define PCL_RCV_INT_ALL_ENABLE                 \
+       (PCL_CFG_BW_MGT_ENABLE | PCL_CFG_LINK_AUTO_BW_ENABLE \
+        | PCL_CFG_AER_RC_ERR_MSI_ENABLE | PCL_CFG_PME_MSI_ENABLE)
+
+#define PCL_RCV_INTX                   0x810c
+#define PCL_RADM_INTD_ENABLE           BIT(19)
+#define PCL_RADM_INTC_ENABLE           BIT(18)
+#define PCL_RADM_INTB_ENABLE           BIT(17)
+#define PCL_RADM_INTA_ENABLE           BIT(16)
+#define PCL_RADM_INTD_STATUS           BIT(3)
+#define PCL_RADM_INTC_STATUS           BIT(2)
+#define PCL_RADM_INTB_STATUS           BIT(1)
+#define PCL_RADM_INTA_STATUS           BIT(0)
+#define PCL_RCV_INTX_ALL_ENABLE                        \
+       (PCL_RADM_INTD_ENABLE | PCL_RADM_INTC_ENABLE \
+        | PCL_RADM_INTB_ENABLE | PCL_RADM_INTA_ENABLE)
+
+#define PCL_STATUS_LINK                        0x8140
+#define PCL_RDLH_LINK_UP               BIT(1)
+#define PCL_XMLH_LINK_UP               BIT(0)
+
+struct uniphier_pcie_priv {
+       void __iomem *base;
+       struct dw_pcie pci;
+       struct clk *clk;
+       struct reset_control *rst;
+       struct phy *phy;
+       struct irq_domain *irq_domain;
+};
+
+#define to_uniphier_pcie(x)    dev_get_drvdata((x)->dev)
+
+static void uniphier_pcie_ltssm_enable(struct uniphier_pcie_priv *priv)
+{
+       u32 val;
+
+       val = readl(priv->base + PCL_APP_READY_CTRL);
+       val |= PCL_APP_LTSSM_ENABLE;
+       writel(val, priv->base + PCL_APP_READY_CTRL);
+}
+
+static void uniphier_pcie_ltssm_disable(struct uniphier_pcie_priv *priv)
+{
+       u32 val;
+
+       val = readl(priv->base + PCL_APP_READY_CTRL);
+       val &= ~PCL_APP_LTSSM_ENABLE;
+       writel(val, priv->base + PCL_APP_READY_CTRL);
+}
+
+static void uniphier_pcie_init_rc(struct uniphier_pcie_priv *priv)
+{
+       u32 val;
+
+       /* use auxiliary power detection */
+       val = readl(priv->base + PCL_APP_PM0);
+       val |= PCL_SYS_AUX_PWR_DET;
+       writel(val, priv->base + PCL_APP_PM0);
+
+       /* assert PERST# */
+       val = readl(priv->base + PCL_PINCTRL0);
+       val &= ~(PCL_PERST_NOE_REGVAL | PCL_PERST_OUT_REGVAL
+                | PCL_PERST_PLDN_REGVAL);
+       val |= PCL_PERST_NOE_REGEN | PCL_PERST_OUT_REGEN
+               | PCL_PERST_PLDN_REGEN;
+       writel(val, priv->base + PCL_PINCTRL0);
+
+       uniphier_pcie_ltssm_disable(priv);
+
+       usleep_range(100000, 200000);
+
+       /* deassert PERST# */
+       val = readl(priv->base + PCL_PINCTRL0);
+       val |= PCL_PERST_OUT_REGVAL | PCL_PERST_OUT_REGEN;
+       writel(val, priv->base + PCL_PINCTRL0);
+}
+
+static int uniphier_pcie_wait_rc(struct uniphier_pcie_priv *priv)
+{
+       u32 status;
+       int ret;
+
+       /* wait PIPE clock */
+       ret = readl_poll_timeout(priv->base + PCL_PIPEMON, status,
+                                status & PCL_PCLK_ALIVE, 100000, 1000000);
+       if (ret) {
+               dev_err(priv->pci.dev,
+                       "Failed to initialize controller in RC mode\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int uniphier_pcie_link_up(struct dw_pcie *pci)
+{
+       struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+       u32 val, mask;
+
+       val = readl(priv->base + PCL_STATUS_LINK);
+       mask = PCL_RDLH_LINK_UP | PCL_XMLH_LINK_UP;
+
+       return (val & mask) == mask;
+}
+
+static int uniphier_pcie_establish_link(struct dw_pcie *pci)
+{
+       struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+       int ret;
+
+       if (dw_pcie_link_up(pci))
+               return 0;
+
+       uniphier_pcie_ltssm_enable(priv);
+
+       ret = dw_pcie_wait_for_link(pci);
+       if (ret == -ETIMEDOUT) {
+               dev_warn(pci->dev, "Link not up\n");
+               ret = 0;
+       }
+
+       return ret;
+}
+
+static void uniphier_pcie_stop_link(struct dw_pcie *pci)
+{
+       struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+
+       uniphier_pcie_ltssm_disable(priv);
+}
+
+static int uniphier_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+                                 irq_hw_number_t hwirq)
+{
+       irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+       irq_set_chip_data(irq, domain->host_data);
+
+       return 0;
+}
+
+static const struct irq_domain_ops uniphier_intx_domain_ops = {
+       .map = uniphier_pcie_intx_map,
+};
+
+static int uniphier_pcie_init_irq_domain(struct pcie_port *pp)
+{
+       struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+       struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+       struct device_node *np = pci->dev->of_node;
+       struct device_node *np_intc = of_get_next_child(np, NULL);
+
+       if (!np_intc) {
+               dev_err(pci->dev, "Failed to get child node\n");
+               return -ENODEV;
+       }
+
+       priv->irq_domain = irq_domain_add_linear(np_intc, PCI_NUM_INTX,
+                                                &uniphier_intx_domain_ops,
+                                                pp);
+       if (!priv->irq_domain) {
+               dev_err(pci->dev, "Failed to get INTx domain\n");
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static void uniphier_pcie_irq_enable(struct uniphier_pcie_priv *priv)
+{
+       writel(PCL_RCV_INT_ALL_ENABLE, priv->base + PCL_RCV_INT);
+       writel(PCL_RCV_INTX_ALL_ENABLE, priv->base + PCL_RCV_INTX);
+}
+
+static void uniphier_pcie_irq_disable(struct uniphier_pcie_priv *priv)
+{
+       writel(0, priv->base + PCL_RCV_INT);
+       writel(0, priv->base + PCL_RCV_INTX);
+}
+
+static irqreturn_t uniphier_pcie_irq_handler(int irq, void *arg)
+{
+       struct uniphier_pcie_priv *priv = arg;
+       struct dw_pcie *pci = &priv->pci;
+       u32 val;
+
+       /* INT for debug */
+       val = readl(priv->base + PCL_RCV_INT);
+
+       if (val & PCL_CFG_BW_MGT_STATUS)
+               dev_dbg(pci->dev, "Link Bandwidth Management Event\n");
+       if (val & PCL_CFG_LINK_AUTO_BW_STATUS)
+               dev_dbg(pci->dev, "Link Autonomous Bandwidth Event\n");
+       if (val & PCL_CFG_AER_RC_ERR_MSI_STATUS)
+               dev_dbg(pci->dev, "Root Error\n");
+       if (val & PCL_CFG_PME_MSI_STATUS)
+               dev_dbg(pci->dev, "PME Interrupt\n");
+
+       writel(val, priv->base + PCL_RCV_INT);
+
+       /* INTx */
+       val = readl(priv->base + PCL_RCV_INTX);
+
+       if (val & PCL_RADM_INTA_STATUS)
+               generic_handle_irq(irq_find_mapping(priv->irq_domain, 0));
+       if (val & PCL_RADM_INTB_STATUS)
+               generic_handle_irq(irq_find_mapping(priv->irq_domain, 1));
+       if (val & PCL_RADM_INTC_STATUS)
+               generic_handle_irq(irq_find_mapping(priv->irq_domain, 2));
+       if (val & PCL_RADM_INTD_STATUS)
+               generic_handle_irq(irq_find_mapping(priv->irq_domain, 3));
+
+       writel(val, priv->base + PCL_RCV_INTX);
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t uniphier_pcie_msi_irq_handler(int irq, void *arg)
+{
+       struct pcie_port *pp = arg;
+
+       return dw_handle_msi_irq(pp);
+}
+
+static int uniphier_pcie_host_init(struct pcie_port *pp)
+{
+       struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+       int ret;
+
+       dw_pcie_setup_rc(pp);
+       ret = uniphier_pcie_establish_link(pci);
+       if (ret)
+               return ret;
+
+       if (IS_ENABLED(CONFIG_PCI_MSI))
+               dw_pcie_msi_init(pp);
+
+       return 0;
+}
+
+static const struct dw_pcie_host_ops uniphier_pcie_host_ops = {
+       .host_init = uniphier_pcie_host_init,
+};
+
+static int uniphier_add_pcie_port(struct uniphier_pcie_priv *priv,
+                                 struct platform_device *pdev)
+{
+       struct dw_pcie *pci = &priv->pci;
+       struct pcie_port *pp = &pci->pp;
+       struct device *dev = &pdev->dev;
+       int ret;
+
+       pp->root_bus_nr = -1;
+       pp->ops = &uniphier_pcie_host_ops;
+
+       pp->irq = platform_get_irq_byname(pdev, "intx");
+       if (pp->irq < 0) {
+               dev_err(dev, "Failed to get intx irq\n");
+               return pp->irq;
+       }
+
+       ret = devm_request_irq(dev, pp->irq, uniphier_pcie_irq_handler,
+                              IRQF_SHARED, "pcie", priv);
+       if (ret) {
+               dev_err(dev, "Failed to request irq %d\n", pp->irq);
+               return ret;
+       }
+
+       ret = uniphier_pcie_init_irq_domain(pp);
+       if (ret)
+               return ret;
+
+       if (IS_ENABLED(CONFIG_PCI_MSI)) {
+               pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+               if (pp->msi_irq < 0)
+                       return pp->msi_irq;
+
+               ret = devm_request_irq(dev, pp->msi_irq,
+                                      uniphier_pcie_msi_irq_handler,
+                                      IRQF_SHARED, "pcie-msi", pp);
+               if (ret) {
+                       dev_err(dev, "failed to request msi_irq %d\n",
+                               pp->msi_irq);
+                       return ret;
+               }
+       }
+
+       ret = dw_pcie_host_init(pp);
+       if (ret) {
+               dev_err(dev, "Failed to initialize host (%d)\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int uniphier_pcie_host_enable(struct uniphier_pcie_priv *priv)
+{
+       int ret;
+
+       ret = clk_prepare_enable(priv->clk);
+       if (ret)
+               return ret;
+
+       ret = reset_control_deassert(priv->rst);
+       if (ret)
+               goto out_clk_disable;
+
+       uniphier_pcie_init_rc(priv);
+
+       ret = phy_init(priv->phy);
+       if (ret)
+               goto out_rst_assert;
+
+       ret = uniphier_pcie_wait_rc(priv);
+       if (ret)
+               goto out_phy_exit;
+
+       uniphier_pcie_irq_enable(priv);
+
+       return 0;
+
+out_phy_exit:
+       phy_exit(priv->phy);
+out_rst_assert:
+       reset_control_assert(priv->rst);
+out_clk_disable:
+       clk_disable_unprepare(priv->clk);
+
+       return ret;
+}
+
+static void uniphier_pcie_host_disable(struct uniphier_pcie_priv *priv)
+{
+       uniphier_pcie_irq_disable(priv);
+       phy_exit(priv->phy);
+       reset_control_assert(priv->rst);
+       clk_disable_unprepare(priv->clk);
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+       .start_link = uniphier_pcie_establish_link,
+       .stop_link = uniphier_pcie_stop_link,
+       .link_up = uniphier_pcie_link_up,
+};
+
+static int uniphier_pcie_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct uniphier_pcie_priv *priv;
+       struct resource *res;
+       int ret;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       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);
+
+       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))
+               return PTR_ERR(priv->phy);
+
+       platform_set_drvdata(pdev, priv);
+
+       ret = uniphier_pcie_host_enable(priv);
+       if (ret)
+               return ret;
+
+       return uniphier_add_pcie_port(priv, pdev);
+}
+
+static int uniphier_pcie_remove(struct platform_device *pdev)
+{
+       struct uniphier_pcie_priv *priv = platform_get_drvdata(pdev);
+
+       uniphier_pcie_host_disable(priv);
+
+       return 0;
+}
+
+static const struct of_device_id uniphier_pcie_match[] = {
+       { .compatible = "socionext,uniphier-pcie", },
+       { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, uniphier_pcie_match);
+
+static struct platform_driver uniphier_pcie_driver = {
+       .probe  = uniphier_pcie_probe,
+       .remove = uniphier_pcie_remove,
+       .driver = {
+               .name = "uniphier-pcie",
+               .of_match_table = uniphier_pcie_match,
+       },
+};
+builtin_platform_driver(uniphier_pcie_driver);
+
+MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunih...@socionext.com>");
+MODULE_DESCRIPTION("UniPhier PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

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