powerpc/virtex: Add support for Xilinx PCI host bridge

This patch adds support for the Xilinx plbv46-pci-1.03.a PCI host
bridge IPcore.

Signed-off-by: Roderick Colenbrander <thunderbird2k@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

2 files changed, 133 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index b33b28a6fe12..2d1c87dd5d14 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_IPIC)		+= ipic.o
 obj-$(CONFIG_4xx)               += uic.o
 obj-$(CONFIG_4xx_SOC)           += ppc4xx_soc.o
 obj-$(CONFIG_XILINX_VIRTEX)     += xilinx_intc.o
+obj-$(CONFIG_XILINX_PCI)        += xilinx_pci.o
 obj-$(CONFIG_OF_RTC)            += of_rtc.o
 ifeq ($(CONFIG_PCI),y)
 obj-$(CONFIG_4xx)               += ppc4xx_pci.o
diff --git a/arch/powerpc/sysdev/xilinx_pci.c b/arch/powerpc/sysdev/xilinx_pci.c
new file mode 100644
index 000000000000..1453b0eed220
--- /dev/null
+++ b/arch/powerpc/sysdev/xilinx_pci.c
@@ -0,0 +1,132 @@
+/*
+ * PCI support for Xilinx plbv46_pci soft-core which can be used on
+ * Xilinx Virtex ML410 / ML510 boards.
+ *
+ * Copyright 2009 Roderick Colenbrander
+ * Copyright 2009 Secret Lab Technologies Ltd.
+ *
+ * The pci bridge fixup code was copied from ppc4xx_pci.c and was written
+ * by Benjamin Herrenschmidt.
+ * Copyright 2007 Ben. Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/pci.h>
+#include <mm/mmu_decl.h>
+#include <asm/io.h>
+#include <asm/xilinx_pci.h>
+
+#define XPLB_PCI_ADDR 0x10c
+#define XPLB_PCI_DATA 0x110
+#define XPLB_PCI_BUS  0x114
+
+#define PCI_HOST_ENABLE_CMD PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY
+
+static struct of_device_id xilinx_pci_match[] = {
+        { .compatible = "xlnx,plbv46-pci-1.03.a", },
+        {}
+};
+
+/**
+ * xilinx_pci_fixup_bridge - Block Xilinx PHB configuration.
+ */
+static void xilinx_pci_fixup_bridge(struct pci_dev *dev)
+{
+        struct pci_controller *hose;
+        int i;
+
+        if (dev->devfn || dev->bus->self)
+                return;
+
+        hose = pci_bus_to_host(dev->bus);
+        if (!hose)
+                return;
+
+        if (!of_match_node(xilinx_pci_match, hose->dn))
+                return;
+
+        /* Hide the PCI host BARs from the kernel as their content doesn't
+         * fit well in the resource management
+         */
+        for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+                dev->resource[i].start = 0;
+                dev->resource[i].end = 0;
+                dev->resource[i].flags = 0;
+        }
+
+        dev_info(&dev->dev, "Hiding Xilinx plb-pci host bridge resources %s\n",
+                 pci_name(dev));
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, xilinx_pci_fixup_bridge);
+
+/**
+ * xilinx_pci_exclude_device - Don't do config access for non-root bus
+ *
+ * This is a hack.  Config access to any bus other than bus 0 does not
+ * currently work on the ML510 so we prevent it here.
+ */
+static int
+xilinx_pci_exclude_device(struct pci_controller *hose, u_char bus, u8 devfn)
+{
+        return (bus != 0);
+}
+
+/**
+ * xilinx_pci_init - Find and register a Xilinx PCI host bridge
+ */
+void __init xilinx_pci_init(void)
+{
+        struct pci_controller *hose;
+        struct resource r;
+        void __iomem *pci_reg;
+        struct device_node *pci_node;
+
+        pci_node = of_find_matching_node(NULL, xilinx_pci_match);
+        if(!pci_node)
+                return;
+
+        if (of_address_to_resource(pci_node, 0, &r)) {
+                pr_err("xilinx-pci: cannot resolve base address\n");
+                return;
+        }
+
+        hose = pcibios_alloc_controller(pci_node);
+        if (!hose) {
+                pr_err("xilinx-pci: pcibios_alloc_controller() failed\n");
+                return;
+        }
+
+        /* Setup config space */
+        setup_indirect_pci(hose, r.start + XPLB_PCI_ADDR,
+                           r.start + XPLB_PCI_DATA,
+                           PPC_INDIRECT_TYPE_SET_CFG_TYPE);
+
+        /* According to the xilinx plbv46_pci documentation the soft-core starts
+         * a self-init when the bus master enable bit is set. Without this bit
+         * set the pci bus can't be scanned.
+         */
+        early_write_config_word(hose, 0, 0, PCI_COMMAND, PCI_HOST_ENABLE_CMD);
+
+        /* Set the max latency timer to 255 */
+        early_write_config_byte(hose, 0, 0, PCI_LATENCY_TIMER, 0xff);
+
+        /* Set the max bus number to 255 */
+        pci_reg = of_iomap(pci_node, 0);
+        out_8(pci_reg + XPLB_PCI_BUS, 0xff);
+        iounmap(pci_reg);
+
+        /* Nothing past the root bridge is working right now.  By default
+         * exclude config access to anything except bus 0 */
+        if (!ppc_md.pci_exclude_device)
+                ppc_md.pci_exclude_device = xilinx_pci_exclude_device;
+
+        /* Register the host bridge with the linux kernel! */
+        pci_process_bridge_OF_ranges(hose, pci_node, 1);
+
+        pr_info("xilinx-pci: Registered PCI host bridge\n");
+}