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path: root/drivers/pci/host/pci-keystone.c
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Diffstat (limited to 'drivers/pci/host/pci-keystone.c')
-rw-r--r--drivers/pci/host/pci-keystone.c415
1 files changed, 415 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
new file mode 100644
index 000000000000..1b893bc8b842
--- /dev/null
+++ b/drivers/pci/host/pci-keystone.c
@@ -0,0 +1,415 @@
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/irqchip/chained_irq.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/irqdomain.h>
+#include <linux/module.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"
+
+/* driver specific constants */
+#define MAX_MSI_HOST_IRQS 8
+#define MAX_LEGACY_HOST_IRQS 4
+
+/* 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) container_of(x, struct keystone_pcie, pp)
+
+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 pcie_port *pp = &ks_pcie->pp;
+ int count = 200;
+
+ dw_pcie_setup_rc(pp);
+
+ if (dw_pcie_link_up(pp)) {
+ dev_err(pp->dev, "Link already up\n");
+ return 0;
+ }
+
+ ks_dw_pcie_initiate_link_train(ks_pcie);
+ /* check if the link is up or not */
+ while (!dw_pcie_link_up(pp)) {
+ usleep_range(100, 1000);
+ if (--count) {
+ ks_dw_pcie_initiate_link_train(ks_pcie);
+ continue;
+ }
+ dev_err(pp->dev, "phy link never came up\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void ks_pcie_msi_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+ struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
+ u32 offset = irq - ks_pcie->msi_host_irqs[0];
+ struct pcie_port *pp = &ks_pcie->pp;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+
+ dev_dbg(pp->dev, "ks_pci_msi_irq_handler, 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_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(unsigned int irq, struct irq_desc *desc)
+{
+ struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
+ struct pcie_port *pp = &ks_pcie->pp;
+ u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+
+ dev_dbg(pp->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, ret = -EINVAL;
+ struct device *dev = ks_pcie->pp.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 = MAX_LEGACY_HOST_IRQS;
+ 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_find_node_by_name(np_pcie, controller);
+ if (!(*np_temp)) {
+ dev_err(dev, "Node for %s is absent\n", controller);
+ goto out;
+ }
+ temp = of_irq_count(*np_temp);
+ if (!temp)
+ goto out;
+ 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] < 0)
+ break;
+ }
+ if (temp) {
+ *num_irqs = temp;
+ ret = 0;
+ }
+out:
+ return ret;
+}
+
+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_handler_data(ks_pcie->legacy_host_irqs[i], ks_pcie);
+ irq_set_chained_handler(ks_pcie->legacy_host_irqs[i],
+ ks_pcie_legacy_irq_handler);
+ }
+ 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(ks_pcie->msi_host_irqs[i],
+ ks_pcie_msi_irq_handler);
+ irq_set_handler_data(ks_pcie->msi_host_irqs[i],
+ 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 void __init ks_pcie_host_init(struct pcie_port *pp)
+{
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+ 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),
+ pp->dbi_base + PCI_IO_BASE);
+
+ /* update the Vendor ID */
+ writew(ks_pcie->device_id, pp->dbi_base + PCI_DEVICE_ID);
+
+ /* update the DEV_STAT_CTRL to publish right mrrs */
+ val = readl(pp->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
+ val &= ~PCI_EXP_DEVCTL_READRQ;
+ /* set the mrrs to 256 bytes */
+ val |= BIT(12);
+ writel(val, pp->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");
+}
+
+static struct 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,
+ .link_up = ks_dw_pcie_link_up,
+ .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,
+ .scan_bus = ks_dw_pcie_v3_65_scan_bus,
+};
+
+static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
+ struct platform_device *pdev)
+{
+ struct pcie_port *pp = &ks_pcie->pp;
+ 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;
+ }
+
+ pp->root_bus_nr = -1;
+ pp->ops = &keystone_pcie_host_ops;
+ ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to initialize host\n");
+ return ret;
+ }
+
+ return ret;
+}
+
+static const struct of_device_id ks_pcie_of_match[] = {
+ {
+ .type = "pci",
+ .compatible = "ti,keystone-pcie",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ks_pcie_of_match);
+
+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 keystone_pcie *ks_pcie;
+ struct pcie_port *pp;
+ struct resource *res;
+ void __iomem *reg_p;
+ struct phy *phy;
+ int ret = 0;
+
+ ks_pcie = devm_kzalloc(&pdev->dev, sizeof(*ks_pcie),
+ GFP_KERNEL);
+ if (!ks_pcie) {
+ dev_err(dev, "no memory for keystone pcie\n");
+ return -ENOMEM;
+ }
+ pp = &ks_pcie->pp;
+
+ /* initialize SerDes Phy if present */
+ phy = devm_phy_get(dev, "pcie-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));
+
+ pp->dev = dev;
+ 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;
+
+ 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",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(ks_pcie_of_match),
+ },
+};
+
+module_platform_driver(ks_pcie_driver);
+
+MODULE_AUTHOR("Murali Karicheri <m-karicheri2@ti.com>");
+MODULE_DESCRIPTION("Keystone PCIe host controller driver");
+MODULE_LICENSE("GPL v2");