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
  29         pci_add_resource_offset(&resources, &info->io_space,
  30                                 info->io_space.start - 0x1000);
  31         pci_add_resource(&resources, &info->mem_space);
  32         info->busn.flags = IORESOURCE_BUS;
  33         pci_add_resource(&resources, &info->busn);
  34
  35         root_bus = pci_scan_root_bus(&ofdev->dev, 0, info->ops, info,
  36                                      &resources);
  37         if (root_bus) {
  38                 /* Setup IRQs of all devices using custom routines */
  39                 pci_fixup_irqs(pci_common_swizzle, info->map_irq);
  40
  41                 /* Assign devices with resources */
  42                 pci_assign_unassigned_resources();
  43         } else {
  44                 pci_free_resource_list(&resources);
  45         }
  46 }
  47
  48 void pcibios_fixup_bus(struct pci_bus *pbus)
  49 {
  50         struct pci_dev *dev;
  51         int i, has_io, has_mem;
  52         u16 cmd;
  53
  54         list_for_each_entry(dev, &pbus->devices, bus_list) {
  55                 /*
  56                  * We can not rely on that the bootloader has enabled I/O
  57                  * or memory access to PCI devices. Instead we enable it here
  58                  * if the device has BARs of respective type.
  59                  */
  60                 has_io = has_mem = 0;
  61                 for (i = 0; i < PCI_ROM_RESOURCE; i++) {
  62                         unsigned long f = dev->resource[i].flags;
  63                         if (f & IORESOURCE_IO)
  64                                 has_io = 1;
  65                         else if (f & IORESOURCE_MEM)
  66                                 has_mem = 1;
  67                 }
  68                 /* ROM BARs are mapped into 32-bit memory space */
  69                 if (dev->resource[PCI_ROM_RESOURCE].end != 0) {
  70                         dev->resource[PCI_ROM_RESOURCE].flags |=
  71                                                         IORESOURCE_ROM_ENABLE;
  72                         has_mem = 1;
  73                 }
  74                 pci_bus_read_config_word(pbus, dev->devfn, PCI_COMMAND, &cmd);
  75                 if (has_io && !(cmd & PCI_COMMAND_IO)) {
  76 #ifdef CONFIG_PCI_DEBUG
  77                         printk(KERN_INFO "LEONPCI: Enabling I/O for dev %s\n",
  78                                          pci_name(dev));
  79 #endif
  80                         cmd |= PCI_COMMAND_IO;
  81                         pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
  82                                                                         cmd);
  83                 }
  84                 if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
  85 #ifdef CONFIG_PCI_DEBUG
  86                         printk(KERN_INFO "LEONPCI: Enabling MEMORY for dev"
  87                                          "%s\n", pci_name(dev));
  88 #endif
  89                         cmd |= PCI_COMMAND_MEMORY;
  90                         pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
  91                                                                         cmd);
  92                 }
  93         }
  94 }
  95
  96 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
  97                                 resource_size_t size, resource_size_t align)
  98 {
  99         return res->start;
 100 }