[RFC PATCH 25/30] PCI: j721e: Add TI J721E PCIe driver

[Kishon Vijay Abraham I]

Add support for PCIe controller in J721E SoC. The controller uses the
Cadence PCIe core programmed by pcie-cadence*.c. The PCIe controller
will work in both host mode and device mode.
Some of the features of the controller are:
  *) Supports both RC mode and EP mode
  *) Supports Legacy, MSI and MSI-X support
  *) Supports upto GEN4 speed mode
  *) Supports SR-IOV
  *) Ability to route all transactions via SMMU

The J721E PCIe wrapper has VMAP block which should be configured
for routing all transactions via SMMU. Add j721e_pcie_quirk() which
gets invoked whenever a new PCIe device is registered and configures
the VMAP block.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
 drivers/pci/controller/Kconfig     |   9 +
 drivers/pci/controller/Makefile    |   1 +
 drivers/pci/controller/pci-j721e.c | 431 +++++++++++++++++++++++++++++
 3 files changed, 441 insertions(+)
 create mode 100644 drivers/pci/controller/pci-j721e.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index 011c57cae4b0..f706aa940f18 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -50,6 +50,15 @@ config PCIE_CADENCE_EP
 
 endmenu
 
+config PCI_J721E
+	bool "J721E PCIe host controller using Cadence PCIe core"
+	depends on PCIE_CADENCE
+	help
+	  Say Y here if you want to support the J721E PCIe controller in host
+	  mode or device mode. This PCIe controller uses the Cadence PCIe core.
+	  This driver also handles legacy interrupts when operating in host
+	  mode.
+
 config PCIE_XILINX_NWL
 	bool "NWL PCIe Core"
 	depends on ARCH_ZYNQMP || COMPILE_TEST
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index d56a507495c5..9fdefff5283c 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_PCIE_CADENCE) += pcie-cadence.o
 obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host.o
 obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep.o
+obj-$(CONFIG_PCI_J721E) += pci-j721e.o
 obj-$(CONFIG_PCI_FTPCI100) += pci-ftpci100.o
 obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o
 obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
diff --git a/drivers/pci/controller/pci-j721e.c b/drivers/pci/controller/pci-j721e.c
new file mode 100644
index 000000000000..712cc6a2dd41
--- /dev/null
+++ b/drivers/pci/controller/pci-j721e.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * pci-j721e - PCIe controller driver for TI's J721E SoCs
+ *
+ * Copyright (C) 2018-2019 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
+ */
+
+#include <dt-bindings/pci/pci.h>
+#include <linux/io.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include "../pci.h"
+#include "pcie-cadence.h"
+
+#define J721E_PCIE_USER_CMD_STATUS	0x4
+#define LINK_TRAINING_ENABLE		BIT(0)
+
+#define J721E_PCIE_USER_LINKSTATUS	0x14
+#define LINK_STATUS			GENMASK(1, 0)
+enum link_status {
+	NO_RECIEVERS_DETECTED,
+	LINK_TRAINING_IN_PROGRESS,
+	LINK_UP_DL_IN_PROGRESS,
+	LINK_UP_DL_COMPLETED,
+};
+
+#define J721E_TRANS_CTRL(a)		((a) * 0xc)
+#define J721E_TRANS_REQ_ID(a)		(((a) * 0xc) + 0x4)
+#define J721E_TRANS_VIRT_ID(a)		(((a) * 0xc) + 0x8)
+
+#define J721E_REQID_MASK		0xffff
+#define J721E_REQID_SHIFT		16
+
+#define J721E_EN			BIT(0)
+#define J721E_ATYPE_SHIFT		16
+
+#define J721E_MODE_RC			BIT(7)
+#define LANE_COUNT_MASK			BIT(8)
+#define LANE_COUNT(n)			((n) << 8)
+
+#define GENERATION_SEL_MASK		GENMASK(1, 0)
+
+#define MAX_LANES			2
+
+enum j721e_atype {
+	PHYS_ADDR,
+	INT_ADDR,
+	VIRT_ADDR,
+	TRANS_ADDR,
+};
+
+#define to_j721e_pcie(x) container_of((x), struct j721e_pcie, plat_data)
+
+struct j721e_pcie {
+	struct device		*dev;
+	struct device_node	*node;
+	u32			mode;
+	u32			num_lanes;
+	struct cdns_pcie_plat_data plat_data;
+	void __iomem		*intd_cfg_base;
+	void __iomem		*user_cfg_base;
+	void __iomem		*vmap_lp_base;
+	u8			vmap_lp_index;
+	bool			enable_smmu;
+};
+
+static inline u32 j721e_pcie_vmap_readl(struct j721e_pcie *pcie, u32 offset)
+{
+	return readl(pcie->vmap_lp_base + offset);
+}
+
+static inline void j721e_pcie_vmap_writel(struct j721e_pcie *pcie, u32 offset,
+					  u32 value)
+{
+	writel(value, pcie->vmap_lp_base + offset);
+}
+
+static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
+{
+	return readl(pcie->intd_cfg_base + offset);
+}
+
+static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
+					  u32 value)
+{
+	writel(value, pcie->intd_cfg_base + offset);
+}
+
+static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
+{
+	return readl(pcie->user_cfg_base + offset);
+}
+
+static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
+					  u32 value)
+{
+	writel(value, pcie->user_cfg_base + offset);
+}
+
+static void j721e_pcie_quirk(struct pci_dev *pci_dev)
+{
+	struct pci_bus *root_bus;
+	struct pci_dev *bridge;
+	struct j721e_pcie *pcie;
+	struct pci_bus *bus;
+	struct device *dev;
+	int index;
+	u32 val;
+
+	static const struct pci_device_id rc_pci_devids[] = {
+		{ PCI_DEVICE(0x104c, 0xb00d),
+		.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
+		{ 0, },
+	};
+
+	dev = pci_get_host_bridge_device(pci_dev);
+	pcie = dev_get_drvdata(dev->parent->parent);
+	bus = pci_dev->bus;
+	index = pcie->vmap_lp_index;
+
+	if (!pcie->enable_smmu)
+		return;
+
+	if (index >= 32)
+		return;
+
+	if (pci_is_root_bus(bus))
+		return;
+
+	root_bus = bus;
+	while (!pci_is_root_bus(root_bus)) {
+		bridge = root_bus->self;
+		root_bus = root_bus->parent;
+	}
+
+	if (pci_match_id(rc_pci_devids, bridge)) {
+		val = J721E_REQID_MASK << J721E_REQID_SHIFT |
+			(bus->number << 8 | pci_dev->devfn);
+		j721e_pcie_vmap_writel(pcie, J721E_TRANS_REQ_ID(index), val);
+		val = VIRT_ADDR << J721E_ATYPE_SHIFT;
+		j721e_pcie_vmap_writel(pcie, J721E_TRANS_VIRT_ID(index), val);
+		j721e_pcie_vmap_writel(pcie, J721E_TRANS_CTRL(index), J721E_EN);
+	}
+
+	pcie->vmap_lp_index++;
+}
+DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, j721e_pcie_quirk);
+
+static int j721e_pcie_start_link(struct cdns_pcie_plat_data *data, bool start)
+{
+	struct j721e_pcie *pcie = to_j721e_pcie(data);
+	u32 reg;
+
+	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
+	if (start)
+		reg |= LINK_TRAINING_ENABLE;
+	else
+		reg &= ~LINK_TRAINING_ENABLE;
+	j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
+
+	return 0;
+}
+
+static bool j721e_pcie_is_link_up(struct cdns_pcie_plat_data *data)
+{
+	struct j721e_pcie *pcie = to_j721e_pcie(data);
+	u32 reg;
+
+	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
+	reg &= LINK_STATUS;
+	if (reg == LINK_UP_DL_COMPLETED)
+		return true;
+
+	return false;
+}
+
+static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon)
+{
+	struct device *dev = pcie->dev;
+	u32 mask = J721E_MODE_RC;
+	u32 mode = pcie->mode;
+	u32 val = 0;
+	int ret = 0;
+
+	if (mode == PCI_MODE_RC)
+		val = J721E_MODE_RC;
+
+	ret = regmap_update_bits(syscon, 0, mask, val);
+	if (ret)
+		dev_err(dev, "failed to set pcie mode\n");
+
+	return ret;
+}
+
+static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
+				     struct regmap *syscon)
+{
+	struct device *dev = pcie->dev;
+	struct device_node *np = dev->of_node;
+	int link_speed;
+	u32 val = 0;
+	int ret;
+
+	link_speed = of_pci_get_max_link_speed(np);
+	if (link_speed < 2)
+		link_speed = 2;
+
+	val = link_speed - 1;
+	ret = regmap_update_bits(syscon, 0, GENERATION_SEL_MASK, val);
+	if (ret)
+		dev_err(dev, "failed to set link speed\n");
+
+	return ret;
+}
+
+static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
+				     struct regmap *syscon)
+{
+	struct device *dev = pcie->dev;
+	u32 lanes = pcie->num_lanes;
+	u32 val = 0;
+	int ret;
+
+	val = LANE_COUNT(lanes - 1);
+	ret = regmap_update_bits(syscon, 0, LANE_COUNT_MASK, val);
+	if (ret)
+		dev_err(dev, "failed to set link count\n");
+
+	return ret;
+}
+
+static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
+{
+	struct device *dev = pcie->dev;
+	struct device_node *node = dev->of_node;
+	struct regmap *syscon;
+	int ret;
+
+	syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
+	if (IS_ERR(syscon)) {
+		dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
+		return PTR_ERR(syscon);
+	}
+
+	ret = j721e_pcie_set_mode(pcie, syscon);
+	if (ret < 0) {
+		dev_err(dev, "Failed to set pci mode\n");
+		return ret;
+	}
+
+	ret = j721e_pcie_set_link_speed(pcie, syscon);
+	if (ret < 0) {
+		dev_err(dev, "Failed to set link speed\n");
+		return ret;
+	}
+
+	ret = j721e_pcie_set_lane_count(pcie, syscon);
+	if (ret < 0) {
+		dev_err(dev, "Failed to set num-lanes\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_j721e_pcie_match[] = {
+	{
+		.compatible = "ti,j721e-pcie",
+	},
+	{},
+};
+
+static int j721e_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct cdns_pcie_plat_data *plat_data;
+	struct platform_device *platform_dev;
+	struct device_node *child_node;
+	struct j721e_pcie *pcie;
+	struct resource *res;
+	void __iomem *base;
+	u32 num_lanes;
+	u32 mode;
+	int ret;
+
+	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->dev = dev;
+	pcie->node = node;
+	plat_data = &pcie->plat_data;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "intd_cfg");
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	pcie->intd_cfg_base = base;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "user_cfg");
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	pcie->user_cfg_base = base;
+
+	plat_data->start_link = j721e_pcie_start_link;
+	plat_data->is_link_up = j721e_pcie_is_link_up;
+
+	ret = of_property_read_u32(node, "pci-mode", &mode);
+	if (ret < 0) {
+		dev_err(dev, "Failed to get pci-mode binding\n");
+		return ret;
+	}
+	pcie->mode = mode;
+
+	ret = of_property_read_u32(node, "num-lanes", &num_lanes);
+	if (ret || num_lanes > MAX_LANES)
+		num_lanes = 1;
+	pcie->num_lanes = num_lanes;
+
+	dev_set_drvdata(dev, pcie);
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "pm_runtime_get_sync failed\n");
+		goto err_get_sync;
+	}
+
+	ret = j721e_pcie_ctrl_init(pcie);
+	if (ret < 0) {
+		dev_err(dev, "pm_runtime_get_sync failed\n");
+		goto err_get_sync;
+	}
+
+	switch (mode) {
+	case PCI_MODE_RC:
+		if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) {
+			ret = -ENODEV;
+			goto err_get_sync;
+		}
+
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						   "vmap");
+		base = devm_ioremap_resource(dev, res);
+		if (IS_ERR(base))
+			goto err_get_sync;
+		pcie->vmap_lp_base = base;
+
+		child_node = of_get_child_by_name(node, "pcie");
+		if (!child_node) {
+			dev_WARN(dev, "pcie-rc node is absent\n");
+			goto err_get_sync;
+		}
+
+		if (of_property_read_bool(child_node, "iommu-map"))
+			pcie->enable_smmu = true;
+
+		platform_dev = of_platform_device_create_pdata(child_node, NULL,
+							       plat_data, dev);
+		if (!platform_dev) {
+			ret = -ENODEV;
+			dev_err(dev, "Failed to create Cadence RC device\n");
+			goto err_get_sync;
+		}
+
+		break;
+	case PCI_MODE_EP:
+		if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) {
+			ret = -ENODEV;
+			goto err_get_sync;
+		}
+
+		child_node = of_get_child_by_name(node, "pcie-ep");
+		if (!child_node) {
+			dev_WARN(dev, "pcie-ep node is absent\n");
+			goto err_get_sync;
+		}
+
+		platform_dev = of_platform_device_create_pdata(child_node, NULL,
+							       plat_data, dev);
+		if (!platform_dev) {
+			ret = -ENODEV;
+			dev_err(dev, "Failed to create Cadence EP device\n");
+			goto err_get_sync;
+		}
+
+		break;
+	default:
+		dev_err(dev, "INVALID device type %d\n", mode);
+	}
+
+	return 0;
+
+err_get_sync:
+	pm_runtime_put(dev);
+	pm_runtime_disable(dev);
+
+	return ret;
+}
+
+static int j721e_pcie_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_put(dev);
+	pm_runtime_disable(dev);
+	of_platform_depopulate(dev);
+
+	return 0;
+}
+
+static struct platform_driver j721e_pcie_driver = {
+	.probe  = j721e_pcie_probe,
+	.remove = j721e_pcie_remove,
+	.driver = {
+		.name	= "j721e-pcie",
+		.of_match_table = of_j721e_pcie_match,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(j721e_pcie_driver);
-- 
2.17.1