1 files changed, 290 insertions, 0 deletions
diff --git a/arch/arm/mach-cns3xxx/pcie.c b/arch/arm/mach-cns3xxx/pcie.c
new file mode 100644
index 000000000..e92fbd679
--- /dev/null
+++ b/arch/arm/mach-cns3xxx/pcie.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#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 "cns3xxx.h"
+#include "core.h"
+
+struct cns3xxx_pcie {
+	void __iomem *host_regs; /* PCI config registers for host bridge */
+	void __iomem *cfg0_regs; /* PCI Type 0 config registers */
+	void __iomem *cfg1_regs; /* PCI Type 1 config registers */
+	unsigned int irqs[2];
+	struct resource res_io;
+	struct resource res_mem;
+	int port;
+	bool linked;
+};
+
+static struct cns3xxx_pcie *sysdata_to_cnspci(void *sysdata)
+{
+	struct pci_sys_data *root = sysdata;
+
+	return root->private_data;
+}
+
+static struct cns3xxx_pcie *pdev_to_cnspci(const 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_map_bus(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);
+	void __iomem *base;
+
+	/* If there is no link, just show the CNS PCI bridge. */
+	if (!cnspci->linked && busno > 0)
+		return NULL;
+
+	/*
+	 * The CNS PCI bridge doesn't fit into the PCI hierarchy, though
+	 * we still want to access it.
+	 * We place the host bridge on bus 0, and the directly connected
+	 * device on bus 1, slot 0.
+	 */
+	if (busno == 0) { /* internal PCIe bus, host bridge device */
+		if (devfn == 0) /* device# and function# are ignored by hw */
+			base = cnspci->host_regs;
+		else
+			return NULL; /* no such device */
+
+	} else if (busno == 1) { /* directly connected PCIe device */
+		if (slot == 0) /* device# is ignored by hw */
+			base = cnspci->cfg0_regs;
+		else
+			return NULL; /* no such device */
+	} else /* remote PCI bus */
+		base = cnspci->cfg1_regs + ((busno & 0xf) << 20);
+
+	return base + where + (devfn << 12);
+}
+
+static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
+				   int where, int size, u32 *val)
+{
+	int ret;
+	u32 mask = (0x1ull << (size * 8)) - 1;
+	int shift = (where % 4) * 8;
+
+	ret = pci_generic_config_read(bus, devfn, where, size, val);
+
+	if (ret == PCIBIOS_SUCCESSFUL && !bus->number && !devfn &&
+	    (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.
+		 */
+		*val = ((((*val << shift) & 0xff) | (0x604 << 16)) >> shift) & mask;
+
+	return ret;
+}
+
+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;
+
+	BUG_ON(request_resource(&iomem_resource, res_io) ||
+	       request_resource(&iomem_resource, res_mem));
+
+	pci_add_resource_offset(&sys->resources, res_io, sys->io_offset);
+	pci_add_resource_offset(&sys->resources, res_mem, sys->mem_offset);
+
+	return 1;
+}
+
+static struct pci_ops cns3xxx_pcie_ops = {
+	.map_bus = cns3xxx_pci_map_bus,
+	.read = cns3xxx_pci_read_config,
+	.write = pci_generic_config_write,
+};
+
+static int cns3xxx_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct cns3xxx_pcie *cnspci = pdev_to_cnspci(dev);
+	int irq = cnspci->irqs[!!dev->bus->number];
+
+	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] = {
+		.host_regs = (void __iomem *)CNS3XXX_PCIE0_HOST_BASE_VIRT,
+		.cfg0_regs = (void __iomem *)CNS3XXX_PCIE0_CFG0_BASE_VIRT,
+		.cfg1_regs = (void __iomem *)CNS3XXX_PCIE0_CFG1_BASE_VIRT,
+		.res_io = {
+			.name = "PCIe0 I/O space",
+			.start = CNS3XXX_PCIE0_IO_BASE,
+			.end = CNS3XXX_PCIE0_CFG0_BASE - 1, /* 16 MiB */
+			.flags = IORESOURCE_IO,
+		},
+		.res_mem = {
+			.name = "PCIe0 non-prefetchable",
+			.start = CNS3XXX_PCIE0_MEM_BASE,
+			.end = CNS3XXX_PCIE0_HOST_BASE - 1, /* 176 MiB */
+			.flags = IORESOURCE_MEM,
+		},
+		.irqs = { IRQ_CNS3XXX_PCIE0_RC, IRQ_CNS3XXX_PCIE0_DEVICE, },
+		.port = 0,
+	},
+	[1] = {
+		.host_regs = (void __iomem *)CNS3XXX_PCIE1_HOST_BASE_VIRT,
+		.cfg0_regs = (void __iomem *)CNS3XXX_PCIE1_CFG0_BASE_VIRT,
+		.cfg1_regs = (void __iomem *)CNS3XXX_PCIE1_CFG1_BASE_VIRT,
+		.res_io = {
+			.name = "PCIe1 I/O space",
+			.start = CNS3XXX_PCIE1_IO_BASE,
+			.end = CNS3XXX_PCIE1_CFG0_BASE - 1, /* 16 MiB */
+			.flags = IORESOURCE_IO,
+		},
+		.res_mem = {
+			.name = "PCIe1 non-prefetchable",
+			.start = CNS3XXX_PCIE1_MEM_BASE,
+			.end = CNS3XXX_PCIE1_HOST_BASE - 1, /* 176 MiB */
+			.flags = IORESOURCE_MEM,
+		},
+		.irqs = { IRQ_CNS3XXX_PCIE1_RC, IRQ_CNS3XXX_PCIE1_DEVICE, },
+		.port = 1,
+	},
+};
+
+static void __init cns3xxx_pcie_check_link(struct cns3xxx_pcie *cnspci)
+{
+	int port = cnspci->port;
+	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 cns3xxx_write_config(struct cns3xxx_pcie *cnspci,
+					 int where, int size, u32 val)
+{
+	void __iomem *base = cnspci->host_regs + (where & 0xffc);
+	u32 v;
+	u32 mask = (0x1ull << (size * 8)) - 1;
+	int shift = (where % 4) * 8;
+
+	v = readl_relaxed(base);
+
+	v &= ~(mask << shift);
+	v |= (val & mask) << shift;
+
+	writel_relaxed(v, base);
+	readl_relaxed(base);
+}
+
+static void __init cns3xxx_pcie_hw_init(struct cns3xxx_pcie *cnspci)
+{
+	u16 mem_base  = cnspci->res_mem.start >> 16;
+	u16 mem_limit = cnspci->res_mem.end   >> 16;
+	u16 io_base   = cnspci->res_io.start  >> 16;
+	u16 io_limit  = cnspci->res_io.end    >> 16;
+
+	cns3xxx_write_config(cnspci, PCI_PRIMARY_BUS, 1, 0);
+	cns3xxx_write_config(cnspci, PCI_SECONDARY_BUS, 1, 1);
+	cns3xxx_write_config(cnspci, PCI_SUBORDINATE_BUS, 1, 1);
+	cns3xxx_write_config(cnspci, PCI_MEMORY_BASE, 2, mem_base);
+	cns3xxx_write_config(cnspci, PCI_MEMORY_LIMIT, 2, mem_limit);
+	cns3xxx_write_config(cnspci, PCI_IO_BASE_UPPER16, 2, io_base);
+	cns3xxx_write_config(cnspci, PCI_IO_LIMIT_UPPER16, 2, io_limit);
+
+	if (!cnspci->linked)
+		return;
+
+	/* Set Device Max_Read_Request_Size to 128 byte */
+	pcie_bus_config = PCIE_BUS_PEER2PEER;
+
+	/* Disable PCIe0 Interrupt Mask INTA to INTD */
+	__raw_writel(~0x3FFF, MISC_PCIE_INT_MASK(cnspci->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;
+}
+
+void __init cns3xxx_pcie_init_late(void)
+{
+	int i;
+	void *private_data;
+	struct hw_pci hw_pci = {
+	       .nr_controllers = 1,
+	       .ops = &cns3xxx_pcie_ops,
+	       .setup = cns3xxx_pci_setup,
+	       .map_irq = cns3xxx_pcie_map_irq,
+	       .private_data = &private_data,
+	};
+
+	pcibios_min_io = 0;
+	pcibios_min_mem = 0;
+
+	hook_fault_code(16 + 6, cns3xxx_pcie_abort_handler, SIGBUS, 0,
+			"imprecise external abort");
+
+	for (i = 0; i < ARRAY_SIZE(cns3xxx_pcie); i++) {
+		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]);
+		private_data = &cns3xxx_pcie[i];
+		pci_common_init(&hw_pci);
+	}
+
+	pci_assign_unassigned_resources();
+}