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 427507a2d69..683f11794cb 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 00000000000..38088c36936
--- /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);