[PATCH 4/9] pci: add DT based ARM Versatile PCI host driver

Rob Herring
2014-12-30T19:28:33Z

From: Rob Herring <robh@kernel.org>

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>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
---
drivers/pci/host/Kconfig | 4 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pci-versatile.c | 305 +++++++++++++++++++++++++++++++++++++++
3 files changed, 310 insertions(+)
create mode 100644 drivers/pci/host/pci-versatile.c

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index c4b6568..7b892a9 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 44c2699..e61d91c 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 0000000..a3e7bc5
--- /dev/null
+++ b/drivers/pci/host/pci-versatile.c
@@ -0,0 +1,305 @@
+/*
+ * 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 *__pci_addr(struct pci_bus *bus,
+ unsigned int devfn, int offset)
+{
+ unsigned int busnr = bus->number;
+
+ /*
+ * Trap out illegal values
+ */
+ BUG_ON(offset > 255);
+ BUG_ON(busnr > 255);
+ BUG_ON(devfn > 255);
+
+ return versatile_cfg_base[1] + ((busnr << 16) |
+ (PCI_SLOT(devfn) << 11) | (PCI_FUNC(devfn) << 8) | offset);
+}
+
+static int versatile_read_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ void __iomem *addr = __pci_addr(bus, devfn, where & ~3);
+ u32 v;
+ int slot = PCI_SLOT(devfn);
+
+ if (pci_slot_ignore & (1 << slot)) {
+ /* Ignore this slot */
+ v = (1 << (8 * size)) - 1;
+ } else {
+ switch (size) {
+ case 1:
+ v = readl(addr);
+ if (where & 2)
+ v >>= 16;
+ if (where & 1)
+ v >>= 8;
+ v &= 0xff;
+ break;
+
+ case 2:
+ v = readl(addr);
+ if (where & 2)
+ v >>= 16;
+ v &= 0xffff;
+ break;
+
+ default:
+ v = readl(addr);
+ break;
+ }
+ }
+
+ *val = v;
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int versatile_write_config(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ void __iomem *addr = __pci_addr(bus, devfn, where);
+ int slot = PCI_SLOT(devfn);
+
+ if (pci_slot_ignore & (1 << slot))
+ return PCIBIOS_SUCCESSFUL;
+
+ switch (size) {
+ case 1:
+ writeb((u8)val, addr);
+ break;
+
+ case 2:
+ writew((u16)val, addr);
+ break;
+
+ case 4:
+ writel(val, addr);
+ break;
+ }
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops pci_versatile_ops = {
+ .read = versatile_read_config,
+ .write = versatile_write_config,
+};
+
+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("GPLv2");
--
2.1.0