arch/powerpc/sysdev/xilinx_pci.c

   1 /*
   2  * PCI support for Xilinx plbv46_pci soft-core which can be used on
   3  * Xilinx Virtex ML410 / ML510 boards.
   4  *
   5  * Copyright 2009 Roderick Colenbrander
   6  * Copyright 2009 Secret Lab Technologies Ltd.
   7  *
   8  * The pci bridge fixup code was copied from ppc4xx_pci.c and was written
   9  * by Benjamin Herrenschmidt.
  10  * Copyright 2007 Ben. Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
  11  *
  12  * This file is licensed under the terms of the GNU General Public License
  13  * version 2. This program is licensed "as is" without any warranty of any
  14  * kind, whether express or implied.
  15  */
  16
  17 #include <linux/ioport.h>
  18 #include <linux/of.h>
  19 #include <linux/pci.h>
  20 #include <mm/mmu_decl.h>
  21 #include <asm/io.h>
  22 #include <asm/xilinx_pci.h>
  23
  24 #define XPLB_PCI_ADDR 0x10c
  25 #define XPLB_PCI_DATA 0x110
  26 #define XPLB_PCI_BUS  0x114
  27
  28 #define PCI_HOST_ENABLE_CMD PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY
  29
  30 static const struct of_device_id xilinx_pci_match[] = {
  31         { .compatible = "xlnx,plbv46-pci-1.03.a", },
  32         {}
  33 };
  34
  35 /**
  36  * xilinx_pci_fixup_bridge - Block Xilinx PHB configuration.
  37  */
  38 static void xilinx_pci_fixup_bridge(struct pci_dev *dev)
  39 {
  40         struct pci_controller *hose;
  41         int i;
  42
  43         if (dev->devfn || dev->bus->self)
  44                 return;
  45
  46         hose = pci_bus_to_host(dev->bus);
  47         if (!hose)
  48                 return;
  49
  50         if (!of_match_node(xilinx_pci_match, hose->dn))
  51                 return;
  52
  53         /* Hide the PCI host BARs from the kernel as their content doesn't
  54          * fit well in the resource management
  55          */
  56         for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
  57                 dev->resource[i].start = 0;
  58                 dev->resource[i].end = 0;
  59                 dev->resource[i].flags = 0;
  60         }
  61
  62         dev_info(&dev->dev, "Hiding Xilinx plb-pci host bridge resources %s\n",
  63                  pci_name(dev));
  64 }
  65 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, xilinx_pci_fixup_bridge);
  66
  67 /**
  68  * xilinx_pci_exclude_device - Don't do config access for non-root bus
  69  *
  70  * This is a hack.  Config access to any bus other than bus 0 does not
  71  * currently work on the ML510 so we prevent it here.
  72  */
  73 static int
  74 xilinx_pci_exclude_device(struct pci_controller *hose, u_char bus, u8 devfn)
  75 {
  76         return (bus != 0);
  77 }
  78
  79 /**
  80  * xilinx_pci_init - Find and register a Xilinx PCI host bridge
  81  */
  82 void __init xilinx_pci_init(void)
  83 {
  84         struct pci_controller *hose;
  85         struct resource r;
  86         void __iomem *pci_reg;
  87         struct device_node *pci_node;
  88
  89         pci_node = of_find_matching_node(NULL, xilinx_pci_match);
  90         if(!pci_node)
  91                 return;
  92
  93         if (of_address_to_resource(pci_node, 0, &r)) {
  94                 pr_err("xilinx-pci: cannot resolve base address\n");
  95                 return;
  96         }
  97
  98         hose = pcibios_alloc_controller(pci_node);
  99         if (!hose) {
 100                 pr_err("xilinx-pci: pcibios_alloc_controller() failed\n");
 101                 return;
 102         }
 103
 104         /* Setup config space */
 105         setup_indirect_pci(hose, r.start + XPLB_PCI_ADDR,
 106                            r.start + XPLB_PCI_DATA,
 107                            PPC_INDIRECT_TYPE_SET_CFG_TYPE);
 108
 109         /* According to the xilinx plbv46_pci documentation the soft-core starts
 110          * a self-init when the bus master enable bit is set. Without this bit
 111          * set the pci bus can't be scanned.
 112          */
 113         early_write_config_word(hose, 0, 0, PCI_COMMAND, PCI_HOST_ENABLE_CMD);
 114
 115         /* Set the max latency timer to 255 */
 116         early_write_config_byte(hose, 0, 0, PCI_LATENCY_TIMER, 0xff);
 117
 118         /* Set the max bus number to 255 */
 119         pci_reg = of_iomap(pci_node, 0);
 120         out_8(pci_reg + XPLB_PCI_BUS, 0xff);
 121         iounmap(pci_reg);
 122
 123         /* Nothing past the root bridge is working right now.  By default
 124          * exclude config access to anything except bus 0 */
 125         if (!ppc_md.pci_exclude_device)
 126                 ppc_md.pci_exclude_device = xilinx_pci_exclude_device;
 127
 128         /* Register the host bridge with the linux kernel! */
 129         pci_process_bridge_OF_ranges(hose, pci_node, 1);
 130
 131         pr_info("xilinx-pci: Registered PCI host bridge\n");
 132 }