ARM: cns3xxx: Add support for PCI Express ports

This patch adds PCIe support for CNS3xxx-based boards. The support
was tested with a directly attached SKY2 NIC, and EHCI USB controller
behind the PLX PEX8112 P2P bridge (to make sure that type1 cfg cycles
work as expected).

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>

2 files changed, 390 insertions, 0 deletions

diff --git a/arch/arm/mach-cns3xxx/Makefile b/arch/arm/mach-cns3xxx/Makefile
index 427507a2d696..683f11794cbe 100644
--- a/arch/arm/mach-cns3xxx/Makefile
+++ b/arch/arm/mach-cns3xxx/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_ARCH_CNS3XXX)              += core.o pm.o
+obj-$(CONFIG_PCI)                       += pcie.o
 obj-$(CONFIG_MACH_CNS3420VB)            += cns3420vb.o
diff --git a/arch/arm/mach-cns3xxx/pcie.c b/arch/arm/mach-cns3xxx/pcie.c
new file mode 100644
index 000000000000..38088c36936c
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/pcie.c
@@ -0,0 +1,389 @@
+/*
+ * PCI-E support for CNS3xxx
+ *
+ * Copyright 2008 Cavium Networks
+ *                Richard Liu <richard.liu@caviumnetworks.com>
+ * Copyright 2010 MontaVista Software, LLC.
+ *                Anton Vorontsov <avorontsov@mvista.com>
+ *
+ * This file 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/init.h>
+#include <linux/kernel.h>
+#include <linux/bug.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <asm/mach/map.h>
+#include <mach/cns3xxx.h>
+#include "core.h"
+
+enum cns3xxx_access_type {
+        CNS3XXX_HOST_TYPE = 0,
+        CNS3XXX_CFG0_TYPE,
+        CNS3XXX_CFG1_TYPE,
+        CNS3XXX_NUM_ACCESS_TYPES,
+};
+
+struct cns3xxx_pcie {
+        struct map_desc cfg_bases[CNS3XXX_NUM_ACCESS_TYPES];
+        unsigned int irqs[2];
+        struct resource res_io;
+        struct resource res_mem;
+        struct hw_pci hw_pci;
+
+        bool linked;
+};
+
+static struct cns3xxx_pcie cns3xxx_pcie[]; /* forward decl. */
+
+static struct cns3xxx_pcie *sysdata_to_cnspci(void *sysdata)
+{
+        struct pci_sys_data *root = sysdata;
+
+        return &cns3xxx_pcie[root->domain];
+}
+
+static struct cns3xxx_pcie *pdev_to_cnspci(struct pci_dev *dev)
+{
+        return sysdata_to_cnspci(dev->sysdata);
+}
+
+static struct cns3xxx_pcie *pbus_to_cnspci(struct pci_bus *bus)
+{
+        return sysdata_to_cnspci(bus->sysdata);
+}
+
+static void __iomem *cns3xxx_pci_cfg_base(struct pci_bus *bus,
+                                  unsigned int devfn, int where)
+{
+        struct cns3xxx_pcie *cnspci = pbus_to_cnspci(bus);
+        int busno = bus->number;
+        int slot = PCI_SLOT(devfn);
+        int offset;
+        enum cns3xxx_access_type type;
+        void __iomem *base;
+
+        /* If there is no link, just show the CNS PCI bridge. */
+        if (!cnspci->linked && (busno > 0 || slot > 0))
+                return NULL;
+
+        /*
+         * The CNS PCI bridge doesn't fit into the PCI hierarchy, though
+         * we still want to access it. For this to work, we must place
+         * the first device on the same bus as the CNS PCI bridge.
+         */
+        if (busno == 0) {
+                if (slot > 1)
+                        return NULL;
+                type = slot;
+        } else {
+                type = CNS3XXX_CFG1_TYPE;
+        }
+
+        base = (void __iomem *)cnspci->cfg_bases[type].virtual;
+        offset = ((busno & 0xf) << 20) | (devfn << 12) | (where & 0xffc);
+
+        return base + offset;
+}
+
+static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
+                                   int where, int size, u32 *val)
+{
+        u32 v;
+        void __iomem *base;
+        u32 mask = (0x1ull << (size * 8)) - 1;
+        int shift = (where % 4) * 8;
+
+        base = cns3xxx_pci_cfg_base(bus, devfn, where);
+        if (!base) {
+                *val = 0xffffffff;
+                return PCIBIOS_SUCCESSFUL;
+        }
+
+        v = __raw_readl(base);
+
+        if (bus->number == 0 && devfn == 0 &&
+                        (where & 0xffc) == PCI_CLASS_REVISION) {
+                /*
+                 * RC's class is 0xb, but Linux PCI driver needs 0x604
+                 * for a PCIe bridge. So we must fixup the class code
+                 * to 0x604 here.
+                 */
+                v &= 0xff;
+                v |= 0x604 << 16;
+        }
+
+        *val = (v >> shift) & mask;
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static int cns3xxx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
+                                    int where, int size, u32 val)
+{
+        u32 v;
+        void __iomem *base;
+        u32 mask = (0x1ull << (size * 8)) - 1;
+        int shift = (where % 4) * 8;
+
+        base = cns3xxx_pci_cfg_base(bus, devfn, where);
+        if (!base)
+                return PCIBIOS_SUCCESSFUL;
+
+        v = __raw_readl(base);
+
+        v &= ~(mask << shift);
+        v |= (val & mask) << shift;
+
+        __raw_writel(v, base);
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static int cns3xxx_pci_setup(int nr, struct pci_sys_data *sys)
+{
+        struct cns3xxx_pcie *cnspci = sysdata_to_cnspci(sys);
+        struct resource *res_io = &cnspci->res_io;
+        struct resource *res_mem = &cnspci->res_mem;
+        struct resource **sysres = sys->resource;
+
+        BUG_ON(request_resource(&iomem_resource, res_io) ||
+               request_resource(&iomem_resource, res_mem));
+
+        sysres[0] = res_io;
+        sysres[1] = res_mem;
+
+        return 1;
+}
+
+static struct pci_ops cns3xxx_pcie_ops = {
+        .read = cns3xxx_pci_read_config,
+        .write = cns3xxx_pci_write_config,
+};
+
+static struct pci_bus *cns3xxx_pci_scan_bus(int nr, struct pci_sys_data *sys)
+{
+        return pci_scan_bus(sys->busnr, &cns3xxx_pcie_ops, sys);
+}
+
+static int cns3xxx_pcie_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
+{
+        struct cns3xxx_pcie *cnspci = pdev_to_cnspci(dev);
+        int irq = cnspci->irqs[slot];
+
+        pr_info("PCIe map irq: %04d:%02x:%02x.%02x slot %d, pin %d, irq: %d\n",
+                pci_domain_nr(dev->bus), dev->bus->number, PCI_SLOT(dev->devfn),
+                PCI_FUNC(dev->devfn), slot, pin, irq);
+
+        return irq;
+}
+
+static struct cns3xxx_pcie cns3xxx_pcie[] = {
+        [0] = {
+                .cfg_bases = {
+                        [CNS3XXX_HOST_TYPE] = {
+                                .virtual = CNS3XXX_PCIE0_HOST_BASE_VIRT,
+                                .pfn = __phys_to_pfn(CNS3XXX_PCIE0_HOST_BASE),
+                                .length = SZ_16M,
+                                .type = MT_DEVICE,
+                        },
+                        [CNS3XXX_CFG0_TYPE] = {
+                                .virtual = CNS3XXX_PCIE0_CFG0_BASE_VIRT,
+                                .pfn = __phys_to_pfn(CNS3XXX_PCIE0_CFG0_BASE),
+                                .length = SZ_16M,
+                                .type = MT_DEVICE,
+                        },
+                        [CNS3XXX_CFG1_TYPE] = {
+                                .virtual = CNS3XXX_PCIE0_CFG1_BASE_VIRT,
+                                .pfn = __phys_to_pfn(CNS3XXX_PCIE0_CFG1_BASE),
+                                .length = SZ_16M,
+                                .type = MT_DEVICE,
+                        },
+                },
+                .res_io = {
+                        .name = "PCIe0 I/O space",
+                        .start = CNS3XXX_PCIE0_IO_BASE,
+                        .end = CNS3XXX_PCIE0_IO_BASE + SZ_16M - 1,
+                        .flags = IORESOURCE_IO,
+                },
+                .res_mem = {
+                        .name = "PCIe0 non-prefetchable",
+                        .start = CNS3XXX_PCIE0_MEM_BASE,
+                        .end = CNS3XXX_PCIE0_MEM_BASE + SZ_16M - 1,
+                        .flags = IORESOURCE_MEM,
+                },
+                .irqs = { IRQ_CNS3XXX_PCIE0_RC, IRQ_CNS3XXX_PCIE0_DEVICE, },
+                .hw_pci = {
+                        .domain = 0,
+                        .swizzle = pci_std_swizzle,
+                        .nr_controllers = 1,
+                        .setup = cns3xxx_pci_setup,
+                        .scan = cns3xxx_pci_scan_bus,
+                        .map_irq = cns3xxx_pcie_map_irq,
+                },
+        },
+        [1] = {
+                .cfg_bases = {
+                        [CNS3XXX_HOST_TYPE] = {
+                                .virtual = CNS3XXX_PCIE1_HOST_BASE_VIRT,
+                                .pfn = __phys_to_pfn(CNS3XXX_PCIE1_HOST_BASE),
+                                .length = SZ_16M,
+                                .type = MT_DEVICE,
+                        },
+                        [CNS3XXX_CFG0_TYPE] = {
+                                .virtual = CNS3XXX_PCIE1_CFG0_BASE_VIRT,
+                                .pfn = __phys_to_pfn(CNS3XXX_PCIE1_CFG0_BASE),
+                                .length = SZ_16M,
+                                .type = MT_DEVICE,
+                        },
+                        [CNS3XXX_CFG1_TYPE] = {
+                                .virtual = CNS3XXX_PCIE1_CFG1_BASE_VIRT,
+                                .pfn = __phys_to_pfn(CNS3XXX_PCIE1_CFG1_BASE),
+                                .length = SZ_16M,
+                                .type = MT_DEVICE,
+                        },
+                },
+                .res_io = {
+                        .name = "PCIe1 I/O space",
+                        .start = CNS3XXX_PCIE1_IO_BASE,
+                        .end = CNS3XXX_PCIE1_IO_BASE + SZ_16M - 1,
+                        .flags = IORESOURCE_IO,
+                },
+                .res_mem = {
+                        .name = "PCIe1 non-prefetchable",
+                        .start = CNS3XXX_PCIE1_MEM_BASE,
+                        .end = CNS3XXX_PCIE1_MEM_BASE + SZ_16M - 1,
+                        .flags = IORESOURCE_MEM,
+                },
+                .irqs = { IRQ_CNS3XXX_PCIE1_RC, IRQ_CNS3XXX_PCIE1_DEVICE, },
+                .hw_pci = {
+                        .domain = 1,
+                        .swizzle = pci_std_swizzle,
+                        .nr_controllers = 1,
+                        .setup = cns3xxx_pci_setup,
+                        .scan = cns3xxx_pci_scan_bus,
+                        .map_irq = cns3xxx_pcie_map_irq,
+                },
+        },
+};
+
+static void __init cns3xxx_pcie_check_link(struct cns3xxx_pcie *cnspci)
+{
+        int port = cnspci->hw_pci.domain;
+        u32 reg;
+        unsigned long time;
+
+        reg = __raw_readl(MISC_PCIE_CTRL(port));
+        /*
+         * Enable Application Request to 1, it will exit L1 automatically,
+         * but when chip back, it will use another clock, still can use 0x1.
+         */
+        reg |= 0x3;
+        __raw_writel(reg, MISC_PCIE_CTRL(port));
+
+        pr_info("PCIe: Port[%d] Enable PCIe LTSSM\n", port);
+        pr_info("PCIe: Port[%d] Check data link layer...", port);
+
+        time = jiffies;
+        while (1) {
+                reg = __raw_readl(MISC_PCIE_PM_DEBUG(port));
+                if (reg & 0x1) {
+                        pr_info("Link up.\n");
+                        cnspci->linked = 1;
+                        break;
+                } else if (time_after(jiffies, time + 50)) {
+                        pr_info("Device not found.\n");
+                        break;
+                }
+        }
+}
+
+static void __init cns3xxx_pcie_hw_init(struct cns3xxx_pcie *cnspci)
+{
+        int port = cnspci->hw_pci.domain;
+        struct pci_sys_data sd = {
+                .domain = port,
+        };
+        struct pci_bus bus = {
+                .number = 0,
+                .ops = &cns3xxx_pcie_ops,
+                .sysdata = &sd,
+        };
+        u32 io_base = cnspci->res_io.start >> 16;
+        u32 mem_base = cnspci->res_mem.start >> 16;
+        u32 host_base = cnspci->cfg_bases[CNS3XXX_HOST_TYPE].pfn;
+        u32 cfg0_base = cnspci->cfg_bases[CNS3XXX_CFG0_TYPE].pfn;
+        u32 devfn = 0;
+        u8 tmp8;
+        u16 pos;
+        u16 dc;
+
+        host_base = (__pfn_to_phys(host_base) - 1) >> 16;
+        cfg0_base = (__pfn_to_phys(cfg0_base) - 1) >> 16;
+
+        pci_bus_write_config_byte(&bus, devfn, PCI_PRIMARY_BUS, 0);
+        pci_bus_write_config_byte(&bus, devfn, PCI_SECONDARY_BUS, 1);
+        pci_bus_write_config_byte(&bus, devfn, PCI_SUBORDINATE_BUS, 1);
+
+        pci_bus_read_config_byte(&bus, devfn, PCI_PRIMARY_BUS, &tmp8);
+        pci_bus_read_config_byte(&bus, devfn, PCI_SECONDARY_BUS, &tmp8);
+        pci_bus_read_config_byte(&bus, devfn, PCI_SUBORDINATE_BUS, &tmp8);
+
+        pci_bus_write_config_word(&bus, devfn, PCI_MEMORY_BASE, mem_base);
+        pci_bus_write_config_word(&bus, devfn, PCI_MEMORY_LIMIT, host_base);
+        pci_bus_write_config_word(&bus, devfn, PCI_IO_BASE_UPPER16, io_base);
+        pci_bus_write_config_word(&bus, devfn, PCI_IO_LIMIT_UPPER16, cfg0_base);
+
+        if (!cnspci->linked)
+                return;
+
+        /* Set Device Max_Read_Request_Size to 128 byte */
+        devfn = PCI_DEVFN(1, 0);
+        pos = pci_bus_find_capability(&bus, devfn, PCI_CAP_ID_EXP);
+        pci_bus_read_config_word(&bus, devfn, pos + PCI_EXP_DEVCTL, &dc);
+        dc &= ~(0x3 << 12);     /* Clear Device Control Register [14:12] */
+        pci_bus_write_config_word(&bus, devfn, pos + PCI_EXP_DEVCTL, dc);
+        pci_bus_read_config_word(&bus, devfn, pos + PCI_EXP_DEVCTL, &dc);
+        if (!(dc & (0x3 << 12)))
+                pr_info("PCIe: Set Device Max_Read_Request_Size to 128 byte\n");
+
+        /* Disable PCIe0 Interrupt Mask INTA to INTD */
+        __raw_writel(~0x3FFF, MISC_PCIE_INT_MASK(port));
+}
+
+static int cns3xxx_pcie_abort_handler(unsigned long addr, unsigned int fsr,
+                                      struct pt_regs *regs)
+{
+        if (fsr & (1 << 10))
+                regs->ARM_pc += 4;
+        return 0;
+}
+
+static int __init cns3xxx_pcie_init(void)
+{
+        int i;
+
+        hook_fault_code(16 + 6, cns3xxx_pcie_abort_handler, SIGBUS,
+                        "imprecise external abort");
+
+        for (i = 0; i < ARRAY_SIZE(cns3xxx_pcie); i++) {
+                iotable_init(cns3xxx_pcie[i].cfg_bases,
+                             ARRAY_SIZE(cns3xxx_pcie[i].cfg_bases));
+                cns3xxx_pwr_clk_en(0x1 << PM_CLK_GATE_REG_OFFSET_PCIE(i));
+                cns3xxx_pwr_soft_rst(0x1 << PM_SOFT_RST_REG_OFFST_PCIE(i));
+                cns3xxx_pcie_check_link(&cns3xxx_pcie[i]);
+                cns3xxx_pcie_hw_init(&cns3xxx_pcie[i]);
+                pci_common_init(&cns3xxx_pcie[i].hw_pci);
+        }
+
+        pci_assign_unassigned_resources();
+
+        return 0;
+}
+device_initcall(cns3xxx_pcie_init);