PCI: versatile: Add DT-based ARM Versatile PB PCIe host driver

This converts the Versatile PCI host code to a platform driver using the
commom DT parsing and setup.  The driver uses only an empty ARM
pci_sys_data struct and does not use pci_common_init_dev init function.
The old host code will be removed in a subsequent commit when Versatile is
completely converted to DT.

I've tested this on QEMU with the sym53c8xx driver in both i/o and memory
mapped modes.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
CC: Russell King <linux@arm.linux.org.uk>
CC: Peter Maydell <peter.maydell@linaro.org>

4 files changed, 250 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index ddb9ac8d32b3..1d38850a4b87 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7210,6 +7210,14 @@ F:	include/linux/pci*
 F:      arch/x86/pci/
 F:      arch/x86/kernel/quirks.c
 
+PCI DRIVER FOR ARM VERSATILE PLATFORM
+M:      Rob Herring <robh@kernel.org>
+L:      linux-pci@vger.kernel.org
+L:      linux-arm-kernel@lists.infradead.org
+S:      Maintained
+F:      Documentation/devicetree/bindings/pci/versatile.txt
+F:      drivers/pci/host/pci-versatile.c
+
 PCI DRIVER FOR APPLIEDMICRO XGENE
 M:      Tanmay Inamdar <tinamdar@apm.com>
 L:      linux-pci@vger.kernel.org
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index c4b6568e486d..7b892a9cc4fc 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -102,4 +102,8 @@ config PCI_LAYERSCAPE
         help
           Say Y here if you want PCIe controller support on Layerscape SoCs.
 
+config PCI_VERSATILE
+        bool "ARM Versatile PB PCI controller"
+        depends on ARCH_VERSATILE
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 44c26998027f..e61d91c92bf1 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
 obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
 obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
+obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o
diff --git a/drivers/pci/host/pci-versatile.c b/drivers/pci/host/pci-versatile.c
new file mode 100644
index 000000000000..341529ca23e8
--- /dev/null
+++ b/drivers/pci/host/pci-versatile.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright 2004 Koninklijke Philips Electronics NV
+ *
+ * Conversion to platform driver and DT:
+ * Copyright 2014 Linaro Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 14/04/2005 Initial version, colin.king@philips.com
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+static void __iomem *versatile_pci_base;
+static void __iomem *versatile_cfg_base[2];
+
+#define PCI_IMAP(m)             (versatile_pci_base + ((m) * 4))
+#define PCI_SMAP(m)             (versatile_pci_base + 0x14 + ((m) * 4))
+#define PCI_SELFID              (versatile_pci_base + 0xc)
+
+#define VP_PCI_DEVICE_ID                0x030010ee
+#define VP_PCI_CLASS_ID                 0x0b400000
+
+static u32 pci_slot_ignore;
+
+static int __init versatile_pci_slot_ignore(char *str)
+{
+        int retval;
+        int slot;
+
+        while ((retval = get_option(&str, &slot))) {
+                if ((slot < 0) || (slot > 31))
+                        pr_err("Illegal slot value: %d\n", slot);
+                else
+                        pci_slot_ignore |= (1 << slot);
+        }
+        return 1;
+}
+__setup("pci_slot_ignore=", versatile_pci_slot_ignore);
+
+
+static void __iomem *versatile_map_bus(struct pci_bus *bus,
+                                       unsigned int devfn, int offset)
+{
+        unsigned int busnr = bus->number;
+
+        if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
+                return NULL;
+
+        return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
+}
+
+static struct pci_ops pci_versatile_ops = {
+        .map_bus = versatile_map_bus,
+        .read   = pci_generic_config_read32,
+        .write  = pci_generic_config_write,
+};
+
+static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
+                                                     struct list_head *res)
+{
+        int err, mem = 1, res_valid = 0;
+        struct device_node *np = dev->of_node;
+        resource_size_t iobase;
+        struct pci_host_bridge_window *win;
+
+        err = of_pci_get_host_bridge_resources(np, 0, 0xff, res, &iobase);
+        if (err)
+                return err;
+
+        list_for_each_entry(win, res, list) {
+                struct resource *parent, *res = win->res;
+
+                switch (resource_type(res)) {
+                case IORESOURCE_IO:
+                        parent = &ioport_resource;
+                        err = pci_remap_iospace(res, iobase);
+                        if (err) {
+                                dev_warn(dev, "error %d: failed to map resource %pR\n",
+                                         err, res);
+                                continue;
+                        }
+                        break;
+                case IORESOURCE_MEM:
+                        parent = &iomem_resource;
+                        res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+
+                        writel(res->start >> 28, PCI_IMAP(mem));
+                        writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
+                        mem++;
+
+                        break;
+                case IORESOURCE_BUS:
+                default:
+                        continue;
+                }
+
+                err = devm_request_resource(dev, parent, res);
+                if (err)
+                        goto out_release_res;
+        }
+
+        if (!res_valid) {
+                dev_err(dev, "non-prefetchable memory resource required\n");
+                err = -EINVAL;
+                goto out_release_res;
+        }
+
+        return 0;
+
+out_release_res:
+        pci_free_resource_list(res);
+        return err;
+}
+
+/* Unused, temporary to satisfy ARM arch code */
+struct pci_sys_data sys;
+
+static int versatile_pci_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        int ret, i, myslot = -1;
+        u32 val;
+        void __iomem *local_pci_cfg_base;
+        struct pci_bus *bus;
+        LIST_HEAD(pci_res);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENODEV;
+        versatile_pci_base = devm_ioremap_resource(&pdev->dev, res);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+        if (!res)
+                return -ENODEV;
+        versatile_cfg_base[0] = devm_ioremap_resource(&pdev->dev, res);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+        if (!res)
+                return -ENODEV;
+        versatile_cfg_base[1] = devm_ioremap_resource(&pdev->dev, res);
+
+        ret = versatile_pci_parse_request_of_pci_ranges(&pdev->dev, &pci_res);
+        if (ret)
+                return ret;
+
+        /*
+         * We need to discover the PCI core first to configure itself
+         * before the main PCI probing is performed
+         */
+        for (i = 0; i < 32; i++) {
+                if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
+                    (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
+                        myslot = i;
+                        break;
+                }
+        }
+        if (myslot == -1) {
+                dev_err(&pdev->dev, "Cannot find PCI core!\n");
+                return -EIO;
+        }
+        /*
+         * Do not to map Versatile FPGA PCI device into memory space
+         */
+        pci_slot_ignore |= (1 << myslot);
+
+        dev_info(&pdev->dev, "PCI core found (slot %d)\n", myslot);
+
+        writel(myslot, PCI_SELFID);
+        local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
+
+        val = readl(local_pci_cfg_base + PCI_COMMAND);
+        val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
+        writel(val, local_pci_cfg_base + PCI_COMMAND);
+
+        /*
+         * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
+         */
+        writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
+        writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
+        writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);
+
+        /*
+         * For many years the kernel and QEMU were symbiotically buggy
+         * in that they both assumed the same broken IRQ mapping.
+         * QEMU therefore attempts to auto-detect old broken kernels
+         * so that they still work on newer QEMU as they did on old
+         * QEMU. Since we now use the correct (ie matching-hardware)
+         * IRQ mapping we write a definitely different value to a
+         * PCI_INTERRUPT_LINE register to tell QEMU that we expect
+         * real hardware behaviour and it need not be backwards
+         * compatible for us. This write is harmless on real hardware.
+         */
+        writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
+
+        pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
+        pci_add_flags(PCI_REASSIGN_ALL_BUS | PCI_REASSIGN_ALL_RSRC);
+
+        bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, &sys, &pci_res);
+        if (!bus)
+                return -ENOMEM;
+
+        pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+        pci_assign_unassigned_bus_resources(bus);
+
+        return 0;
+}
+
+static const struct of_device_id versatile_pci_of_match[] = {
+        { .compatible = "arm,versatile-pci", },
+        { },
+};
+MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
+
+static struct platform_driver versatile_pci_driver = {
+        .driver = {
+                .name = "versatile-pci",
+                .of_match_table = versatile_pci_of_match,
+        },
+        .probe = versatile_pci_probe,
+};
+module_platform_driver(versatile_pci_driver);
+
+MODULE_DESCRIPTION("Versatile PCI driver");
+MODULE_LICENSE("GPL v2");