|  | // SPDX-License-Identifier: GPL-2.0 | 
|  | /* | 
|  | * PCIe host controller driver for Texas Instruments Keystone SoCs | 
|  | * | 
|  | * Copyright (C) 2013-2014 Texas Instruments., Ltd. | 
|  | *		http://www.ti.com | 
|  | * | 
|  | * Author: Murali Karicheri <m-karicheri2@ti.com> | 
|  | * Implementation based on pci-exynos.c and pcie-designware.c | 
|  | */ | 
|  |  | 
|  | #include <linux/irqchip/chained_irq.h> | 
|  | #include <linux/clk.h> | 
|  | #include <linux/delay.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/irqdomain.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/msi.h> | 
|  | #include <linux/of_irq.h> | 
|  | #include <linux/of.h> | 
|  | #include <linux/of_pci.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/phy/phy.h> | 
|  | #include <linux/resource.h> | 
|  | #include <linux/signal.h> | 
|  |  | 
|  | #include "pcie-designware.h" | 
|  | #include "pci-keystone.h" | 
|  |  | 
|  | #define DRIVER_NAME	"keystone-pcie" | 
|  |  | 
|  | /* DEV_STAT_CTRL */ | 
|  | #define PCIE_CAP_BASE		0x70 | 
|  |  | 
|  | /* PCIE controller device IDs */ | 
|  | #define PCIE_RC_K2HK		0xb008 | 
|  | #define PCIE_RC_K2E		0xb009 | 
|  | #define PCIE_RC_K2L		0xb00a | 
|  |  | 
|  | #define to_keystone_pcie(x)	dev_get_drvdata((x)->dev) | 
|  |  | 
|  | static void quirk_limit_mrrs(struct pci_dev *dev) | 
|  | { | 
|  | struct pci_bus *bus = dev->bus; | 
|  | struct pci_dev *bridge = bus->self; | 
|  | static const struct pci_device_id rc_pci_devids[] = { | 
|  | { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK), | 
|  | .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, | 
|  | { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E), | 
|  | .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, | 
|  | { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L), | 
|  | .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, }, | 
|  | { 0, }, | 
|  | }; | 
|  |  | 
|  | if (pci_is_root_bus(bus)) | 
|  | return; | 
|  |  | 
|  | /* look for the host bridge */ | 
|  | while (!pci_is_root_bus(bus)) { | 
|  | bridge = bus->self; | 
|  | bus = bus->parent; | 
|  | } | 
|  |  | 
|  | if (bridge) { | 
|  | /* | 
|  | * Keystone PCI controller has a h/w limitation of | 
|  | * 256 bytes maximum read request size.  It can't handle | 
|  | * anything higher than this.  So force this limit on | 
|  | * all downstream devices. | 
|  | */ | 
|  | if (pci_match_id(rc_pci_devids, bridge)) { | 
|  | if (pcie_get_readrq(dev) > 256) { | 
|  | dev_info(&dev->dev, "limiting MRRS to 256\n"); | 
|  | pcie_set_readrq(dev, 256); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs); | 
|  |  | 
|  | static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie) | 
|  | { | 
|  | struct dw_pcie *pci = ks_pcie->pci; | 
|  | struct pcie_port *pp = &pci->pp; | 
|  | struct device *dev = pci->dev; | 
|  | unsigned int retries; | 
|  |  | 
|  | dw_pcie_setup_rc(pp); | 
|  |  | 
|  | if (dw_pcie_link_up(pci)) { | 
|  | dev_info(dev, "Link already up\n"); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* check if the link is up or not */ | 
|  | for (retries = 0; retries < 5; retries++) { | 
|  | ks_dw_pcie_initiate_link_train(ks_pcie); | 
|  | if (!dw_pcie_wait_for_link(pci)) | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | dev_err(dev, "phy link never came up\n"); | 
|  | return -ETIMEDOUT; | 
|  | } | 
|  |  | 
|  | static void ks_pcie_msi_irq_handler(struct irq_desc *desc) | 
|  | { | 
|  | unsigned int irq = irq_desc_get_irq(desc); | 
|  | struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc); | 
|  | u32 offset = irq - ks_pcie->msi_host_irqs[0]; | 
|  | struct dw_pcie *pci = ks_pcie->pci; | 
|  | struct device *dev = pci->dev; | 
|  | struct irq_chip *chip = irq_desc_get_chip(desc); | 
|  |  | 
|  | dev_dbg(dev, "%s, irq %d\n", __func__, irq); | 
|  |  | 
|  | /* | 
|  | * The chained irq handler installation would have replaced normal | 
|  | * interrupt driver handler so we need to take care of mask/unmask and | 
|  | * ack operation. | 
|  | */ | 
|  | chained_irq_enter(chip, desc); | 
|  | ks_dw_pcie_handle_msi_irq(ks_pcie, offset); | 
|  | chained_irq_exit(chip, desc); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * ks_pcie_legacy_irq_handler() - Handle legacy interrupt | 
|  | * @irq: IRQ line for legacy interrupts | 
|  | * @desc: Pointer to irq descriptor | 
|  | * | 
|  | * Traverse through pending legacy interrupts and invoke handler for each. Also | 
|  | * takes care of interrupt controller level mask/ack operation. | 
|  | */ | 
|  | static void ks_pcie_legacy_irq_handler(struct irq_desc *desc) | 
|  | { | 
|  | unsigned int irq = irq_desc_get_irq(desc); | 
|  | struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc); | 
|  | struct dw_pcie *pci = ks_pcie->pci; | 
|  | struct device *dev = pci->dev; | 
|  | u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0]; | 
|  | struct irq_chip *chip = irq_desc_get_chip(desc); | 
|  |  | 
|  | dev_dbg(dev, ": Handling legacy irq %d\n", irq); | 
|  |  | 
|  | /* | 
|  | * The chained irq handler installation would have replaced normal | 
|  | * interrupt driver handler so we need to take care of mask/unmask and | 
|  | * ack operation. | 
|  | */ | 
|  | chained_irq_enter(chip, desc); | 
|  | ks_dw_pcie_handle_legacy_irq(ks_pcie, irq_offset); | 
|  | chained_irq_exit(chip, desc); | 
|  | } | 
|  |  | 
|  | static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie, | 
|  | char *controller, int *num_irqs) | 
|  | { | 
|  | int temp, max_host_irqs, legacy = 1, *host_irqs; | 
|  | struct device *dev = ks_pcie->pci->dev; | 
|  | struct device_node *np_pcie = dev->of_node, **np_temp; | 
|  |  | 
|  | if (!strcmp(controller, "msi-interrupt-controller")) | 
|  | legacy = 0; | 
|  |  | 
|  | if (legacy) { | 
|  | np_temp = &ks_pcie->legacy_intc_np; | 
|  | max_host_irqs = PCI_NUM_INTX; | 
|  | host_irqs = &ks_pcie->legacy_host_irqs[0]; | 
|  | } else { | 
|  | np_temp = &ks_pcie->msi_intc_np; | 
|  | max_host_irqs = MAX_MSI_HOST_IRQS; | 
|  | host_irqs =  &ks_pcie->msi_host_irqs[0]; | 
|  | } | 
|  |  | 
|  | /* interrupt controller is in a child node */ | 
|  | *np_temp = of_get_child_by_name(np_pcie, controller); | 
|  | if (!(*np_temp)) { | 
|  | dev_err(dev, "Node for %s is absent\n", controller); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | temp = of_irq_count(*np_temp); | 
|  | if (!temp) { | 
|  | dev_err(dev, "No IRQ entries in %s\n", controller); | 
|  | of_node_put(*np_temp); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | if (temp > max_host_irqs) | 
|  | dev_warn(dev, "Too many %s interrupts defined %u\n", | 
|  | (legacy ? "legacy" : "MSI"), temp); | 
|  |  | 
|  | /* | 
|  | * support upto max_host_irqs. In dt from index 0 to 3 (legacy) or 0 to | 
|  | * 7 (MSI) | 
|  | */ | 
|  | for (temp = 0; temp < max_host_irqs; temp++) { | 
|  | host_irqs[temp] = irq_of_parse_and_map(*np_temp, temp); | 
|  | if (!host_irqs[temp]) | 
|  | break; | 
|  | } | 
|  |  | 
|  | of_node_put(*np_temp); | 
|  |  | 
|  | if (temp) { | 
|  | *num_irqs = temp; | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie) | 
|  | { | 
|  | int i; | 
|  |  | 
|  | /* Legacy IRQ */ | 
|  | for (i = 0; i < ks_pcie->num_legacy_host_irqs; i++) { | 
|  | irq_set_chained_handler_and_data(ks_pcie->legacy_host_irqs[i], | 
|  | ks_pcie_legacy_irq_handler, | 
|  | ks_pcie); | 
|  | } | 
|  | ks_dw_pcie_enable_legacy_irqs(ks_pcie); | 
|  |  | 
|  | /* MSI IRQ */ | 
|  | if (IS_ENABLED(CONFIG_PCI_MSI)) { | 
|  | for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) { | 
|  | irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i], | 
|  | ks_pcie_msi_irq_handler, | 
|  | ks_pcie); | 
|  | } | 
|  | } | 
|  |  | 
|  | if (ks_pcie->error_irq > 0) | 
|  | ks_dw_pcie_enable_error_irq(ks_pcie); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * When a PCI device does not exist during config cycles, keystone host gets a | 
|  | * bus error instead of returning 0xffffffff. This handler always returns 0 | 
|  | * for this kind of faults. | 
|  | */ | 
|  | static int keystone_pcie_fault(unsigned long addr, unsigned int fsr, | 
|  | struct pt_regs *regs) | 
|  | { | 
|  | unsigned long instr = *(unsigned long *) instruction_pointer(regs); | 
|  |  | 
|  | if ((instr & 0x0e100090) == 0x00100090) { | 
|  | int reg = (instr >> 12) & 15; | 
|  |  | 
|  | regs->uregs[reg] = -1; | 
|  | regs->ARM_pc += 4; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int __init ks_pcie_host_init(struct pcie_port *pp) | 
|  | { | 
|  | struct dw_pcie *pci = to_dw_pcie_from_pp(pp); | 
|  | struct keystone_pcie *ks_pcie = to_keystone_pcie(pci); | 
|  | u32 val; | 
|  |  | 
|  | ks_pcie_establish_link(ks_pcie); | 
|  | ks_dw_pcie_setup_rc_app_regs(ks_pcie); | 
|  | ks_pcie_setup_interrupts(ks_pcie); | 
|  | writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8), | 
|  | pci->dbi_base + PCI_IO_BASE); | 
|  |  | 
|  | /* update the Vendor ID */ | 
|  | writew(ks_pcie->device_id, pci->dbi_base + PCI_DEVICE_ID); | 
|  |  | 
|  | /* update the DEV_STAT_CTRL to publish right mrrs */ | 
|  | val = readl(pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL); | 
|  | val &= ~PCI_EXP_DEVCTL_READRQ; | 
|  | /* set the mrrs to 256 bytes */ | 
|  | val |= BIT(12); | 
|  | writel(val, pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL); | 
|  |  | 
|  | /* | 
|  | * PCIe access errors that result into OCP errors are caught by ARM as | 
|  | * "External aborts" | 
|  | */ | 
|  | hook_fault_code(17, keystone_pcie_fault, SIGBUS, 0, | 
|  | "Asynchronous external abort"); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct dw_pcie_host_ops keystone_pcie_host_ops = { | 
|  | .rd_other_conf = ks_dw_pcie_rd_other_conf, | 
|  | .wr_other_conf = ks_dw_pcie_wr_other_conf, | 
|  | .host_init = ks_pcie_host_init, | 
|  | .msi_set_irq = ks_dw_pcie_msi_set_irq, | 
|  | .msi_clear_irq = ks_dw_pcie_msi_clear_irq, | 
|  | .get_msi_addr = ks_dw_pcie_get_msi_addr, | 
|  | .msi_host_init = ks_dw_pcie_msi_host_init, | 
|  | .msi_irq_ack = ks_dw_pcie_msi_irq_ack, | 
|  | .scan_bus = ks_dw_pcie_v3_65_scan_bus, | 
|  | }; | 
|  |  | 
|  | static irqreturn_t pcie_err_irq_handler(int irq, void *priv) | 
|  | { | 
|  | struct keystone_pcie *ks_pcie = priv; | 
|  |  | 
|  | return ks_dw_pcie_handle_error_irq(ks_pcie); | 
|  | } | 
|  |  | 
|  | static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie, | 
|  | struct platform_device *pdev) | 
|  | { | 
|  | struct dw_pcie *pci = ks_pcie->pci; | 
|  | struct pcie_port *pp = &pci->pp; | 
|  | struct device *dev = &pdev->dev; | 
|  | int ret; | 
|  |  | 
|  | ret = ks_pcie_get_irq_controller_info(ks_pcie, | 
|  | "legacy-interrupt-controller", | 
|  | &ks_pcie->num_legacy_host_irqs); | 
|  | if (ret) | 
|  | return ret; | 
|  |  | 
|  | if (IS_ENABLED(CONFIG_PCI_MSI)) { | 
|  | ret = ks_pcie_get_irq_controller_info(ks_pcie, | 
|  | "msi-interrupt-controller", | 
|  | &ks_pcie->num_msi_host_irqs); | 
|  | if (ret) | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Index 0 is the platform interrupt for error interrupt | 
|  | * from RC.  This is optional. | 
|  | */ | 
|  | ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0); | 
|  | if (ks_pcie->error_irq <= 0) | 
|  | dev_info(dev, "no error IRQ defined\n"); | 
|  | else { | 
|  | ret = request_irq(ks_pcie->error_irq, pcie_err_irq_handler, | 
|  | IRQF_SHARED, "pcie-error-irq", ks_pcie); | 
|  | if (ret < 0) { | 
|  | dev_err(dev, "failed to request error IRQ %d\n", | 
|  | ks_pcie->error_irq); | 
|  | return ret; | 
|  | } | 
|  | } | 
|  |  | 
|  | pp->ops = &keystone_pcie_host_ops; | 
|  | ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np); | 
|  | if (ret) { | 
|  | dev_err(dev, "failed to initialize host\n"); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct of_device_id ks_pcie_of_match[] = { | 
|  | { | 
|  | .type = "pci", | 
|  | .compatible = "ti,keystone-pcie", | 
|  | }, | 
|  | { }, | 
|  | }; | 
|  |  | 
|  | static const struct dw_pcie_ops dw_pcie_ops = { | 
|  | .link_up = ks_dw_pcie_link_up, | 
|  | }; | 
|  |  | 
|  | static int __exit ks_pcie_remove(struct platform_device *pdev) | 
|  | { | 
|  | struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev); | 
|  |  | 
|  | clk_disable_unprepare(ks_pcie->clk); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int __init ks_pcie_probe(struct platform_device *pdev) | 
|  | { | 
|  | struct device *dev = &pdev->dev; | 
|  | struct dw_pcie *pci; | 
|  | struct keystone_pcie *ks_pcie; | 
|  | struct resource *res; | 
|  | void __iomem *reg_p; | 
|  | struct phy *phy; | 
|  | int ret; | 
|  |  | 
|  | ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL); | 
|  | if (!ks_pcie) | 
|  | return -ENOMEM; | 
|  |  | 
|  | pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL); | 
|  | if (!pci) | 
|  | return -ENOMEM; | 
|  |  | 
|  | pci->dev = dev; | 
|  | pci->ops = &dw_pcie_ops; | 
|  |  | 
|  | ks_pcie->pci = pci; | 
|  |  | 
|  | /* initialize SerDes Phy if present */ | 
|  | phy = devm_phy_get(dev, "pcie-phy"); | 
|  | if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER) | 
|  | return PTR_ERR(phy); | 
|  |  | 
|  | if (!IS_ERR_OR_NULL(phy)) { | 
|  | ret = phy_init(phy); | 
|  | if (ret < 0) | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* index 2 is to read PCI DEVICE_ID */ | 
|  | res = platform_get_resource(pdev, IORESOURCE_MEM, 2); | 
|  | reg_p = devm_ioremap_resource(dev, res); | 
|  | if (IS_ERR(reg_p)) | 
|  | return PTR_ERR(reg_p); | 
|  | ks_pcie->device_id = readl(reg_p) >> 16; | 
|  | devm_iounmap(dev, reg_p); | 
|  | devm_release_mem_region(dev, res->start, resource_size(res)); | 
|  |  | 
|  | ks_pcie->np = dev->of_node; | 
|  | platform_set_drvdata(pdev, ks_pcie); | 
|  | ks_pcie->clk = devm_clk_get(dev, "pcie"); | 
|  | if (IS_ERR(ks_pcie->clk)) { | 
|  | dev_err(dev, "Failed to get pcie rc clock\n"); | 
|  | return PTR_ERR(ks_pcie->clk); | 
|  | } | 
|  | ret = clk_prepare_enable(ks_pcie->clk); | 
|  | if (ret) | 
|  | return ret; | 
|  |  | 
|  | platform_set_drvdata(pdev, ks_pcie); | 
|  |  | 
|  | ret = ks_add_pcie_port(ks_pcie, pdev); | 
|  | if (ret < 0) | 
|  | goto fail_clk; | 
|  |  | 
|  | return 0; | 
|  | fail_clk: | 
|  | clk_disable_unprepare(ks_pcie->clk); | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static struct platform_driver ks_pcie_driver __refdata = { | 
|  | .probe  = ks_pcie_probe, | 
|  | .remove = __exit_p(ks_pcie_remove), | 
|  | .driver = { | 
|  | .name	= "keystone-pcie", | 
|  | .of_match_table = of_match_ptr(ks_pcie_of_match), | 
|  | }, | 
|  | }; | 
|  | builtin_platform_driver(ks_pcie_driver); |