arch/sparc/kernel/leon_pci.c

   1 /*
   2  * leon_pci.c: LEON Host PCI support
   3  *
   4  * Copyright (C) 2011 Aeroflex Gaisler AB, Daniel Hellstrom
   5  *
   6  * Code is partially derived from pcic.c
   7  */
   8
   9 #include <linux/of_device.h>
  10 #include <linux/kernel.h>
  11 #include <linux/pci.h>
  12 #include <linux/export.h>
  13 #include <asm/leon.h>
  14 #include <asm/leon_pci.h>
  15
  16 /* The LEON architecture does not rely on a BIOS or bootloader to setup
  17  * PCI for us. The Linux generic routines are used to setup resources,
  18  * reset values of configuration-space register settings are preserved.
  19  *
  20  * PCI Memory and Prefetchable Memory is direct-mapped. However I/O Space is
  21  * accessed through a Window which is translated to low 64KB in PCI space, the
  22  * first 4KB is not used so 60KB is available.
  23  */
  24 void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
  25 {
  26         LIST_HEAD(resources);
  27         struct pci_bus *root_bus;
  28         struct pci_host_bridge *bridge;
  29         int ret;
  30
  31         bridge = pci_alloc_host_bridge(0);
  32         if (!bridge)
  33                 return;
  34
  35         pci_add_resource_offset(&resources, &info->io_space,
  36                                 info->io_space.start - 0x1000);
  37         pci_add_resource(&resources, &info->mem_space);
  38         info->busn.flags = IORESOURCE_BUS;
  39         pci_add_resource(&resources, &info->busn);
  40
  41         list_splice_init(&resources, &bridge->windows);
  42         bridge->dev.parent = &ofdev->dev;
  43         bridge->sysdata = info;
  44         bridge->busnr = 0;
  45         bridge->ops = info->ops;
  46         bridge->swizzle_irq = pci_common_swizzle;
  47         bridge->map_irq = info->map_irq;
  48
  49         ret = pci_scan_root_bus_bridge(bridge);
  50         if (ret) {
  51                 pci_free_host_bridge(bridge);
  52                 return;
  53         }
  54
  55         root_bus = bridge->bus;
  56
  57         /* Assign devices with resources */
  58         pci_assign_unassigned_resources();
  59         pci_bus_add_devices(root_bus);
  60 }
  61
  62 void pcibios_fixup_bus(struct pci_bus *pbus)
  63 {
  64         struct pci_dev *dev;
  65         int i, has_io, has_mem;
  66         u16 cmd;
  67
  68         list_for_each_entry(dev, &pbus->devices, bus_list) {
  69                 /*
  70                  * We can not rely on that the bootloader has enabled I/O
  71                  * or memory access to PCI devices. Instead we enable it here
  72                  * if the device has BARs of respective type.
  73                  */
  74                 has_io = has_mem = 0;
  75                 for (i = 0; i < PCI_ROM_RESOURCE; i++) {
  76                         unsigned long f = dev->resource[i].flags;
  77                         if (f & IORESOURCE_IO)
  78                                 has_io = 1;
  79                         else if (f & IORESOURCE_MEM)
  80                                 has_mem = 1;
  81                 }
  82                 /* ROM BARs are mapped into 32-bit memory space */
  83                 if (dev->resource[PCI_ROM_RESOURCE].end != 0) {
  84                         dev->resource[PCI_ROM_RESOURCE].flags |=
  85                                                         IORESOURCE_ROM_ENABLE;
  86                         has_mem = 1;
  87                 }
  88                 pci_bus_read_config_word(pbus, dev->devfn, PCI_COMMAND, &cmd);
  89                 if (has_io && !(cmd & PCI_COMMAND_IO)) {
  90 #ifdef CONFIG_PCI_DEBUG
  91                         printk(KERN_INFO "LEONPCI: Enabling I/O for dev %s\n",
  92                                          pci_name(dev));
  93 #endif
  94                         cmd |= PCI_COMMAND_IO;
  95                         pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
  96                                                                         cmd);
  97                 }
  98                 if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
  99 #ifdef CONFIG_PCI_DEBUG
 100                         printk(KERN_INFO "LEONPCI: Enabling MEMORY for dev"
 101                                          "%s\n", pci_name(dev));
 102 #endif
 103                         cmd |= PCI_COMMAND_MEMORY;
 104                         pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
 105                                                                         cmd);
 106                 }
 107         }
 108 }