arch/sh/drivers/pci/pci.c

   1 /*
   2  * arch/sh/drivers/pci/pci.c
   3  *
   4  * Copyright (c) 2002 M. R. Brown  <mrbrown@linux-sh.org>
   5  * Copyright (c) 2004 - 2006 Paul Mundt  <lethal@linux-sh.org>
   6  *
   7  * These functions are collected here to reduce duplication of common
   8  * code amongst the many platform-specific PCI support code files.
   9  *
  10  * These routines require the following board-specific routines:
  11  * void pcibios_fixup_irqs();
  12  *
  13  * See include/asm-sh/pci.h for more information.
  14  *
  15  * This file is subject to the terms and conditions of the GNU General Public
  16  * License.  See the file "COPYING" in the main directory of this archive
  17  * for more details.
  18  */
  19 #include <linux/kernel.h>
  20 #include <linux/pci.h>
  21 #include <linux/init.h>
  22 #include <linux/dma-debug.h>
  23 #include <asm/io.h>
  24
  25 static int __init pcibios_init(void)
  26 {
  27         struct pci_channel *p;
  28         struct pci_bus *bus;
  29         int busno;
  30
  31 #ifdef CONFIG_PCI_AUTO
  32         /* assign resources */
  33         busno = 0;
  34         for (p = board_pci_channels; p->pci_ops != NULL; p++)
  35                 busno = pciauto_assign_resources(busno, p) + 1;
  36 #endif
  37
  38         /* scan the buses */
  39         busno = 0;
  40         for (p = board_pci_channels; p->pci_ops != NULL; p++) {
  41                 bus = pci_scan_bus(busno, p->pci_ops, p);
  42                 busno = bus->subordinate + 1;
  43         }
  44
  45         pci_fixup_irqs(pci_common_swizzle, pcibios_map_platform_irq);
  46
  47         dma_debug_add_bus(&pci_bus_type);
  48
  49         return 0;
  50 }
  51 subsys_initcall(pcibios_init);
  52
  53 /*
  54  *  Called after each bus is probed, but before its children
  55  *  are examined.
  56  */
  57 void __devinit __weak pcibios_fixup_bus(struct pci_bus *bus)
  58 {
  59         pci_read_bridge_bases(bus);
  60 }
  61
  62 void pcibios_align_resource(void *data, struct resource *res,
  63                             resource_size_t size, resource_size_t align)
  64                             __attribute__ ((weak));
  65
  66 /*
  67  * We need to avoid collisions with `mirrored' VGA ports
  68  * and other strange ISA hardware, so we always want the
  69  * addresses to be allocated in the 0x000-0x0ff region
  70  * modulo 0x400.
  71  */
  72 void pcibios_align_resource(void *data, struct resource *res,
  73                             resource_size_t size, resource_size_t align)
  74 {
  75         if (res->flags & IORESOURCE_IO) {
  76                 resource_size_t start = res->start;
  77
  78                 if (start & 0x300) {
  79                         start = (start + 0x3ff) & ~0x3ff;
  80                         res->start = start;
  81                 }
  82         }
  83 }
  84
  85 int pcibios_enable_device(struct pci_dev *dev, int mask)
  86 {
  87         u16 cmd, old_cmd;
  88         int idx;
  89         struct resource *r;
  90
  91         pci_read_config_word(dev, PCI_COMMAND, &cmd);
  92         old_cmd = cmd;
  93         for(idx=0; idx<6; idx++) {
  94                 if (!(mask & (1 << idx)))
  95                         continue;
  96                 r = &dev->resource[idx];
  97                 if (!r->start && r->end) {
  98                         printk(KERN_ERR "PCI: Device %s not available because "
  99                                "of resource collisions\n", pci_name(dev));
 100                         return -EINVAL;
 101                 }
 102                 if (r->flags & IORESOURCE_IO)
 103                         cmd |= PCI_COMMAND_IO;
 104                 if (r->flags & IORESOURCE_MEM)
 105                         cmd |= PCI_COMMAND_MEMORY;
 106         }
 107         if (dev->resource[PCI_ROM_RESOURCE].start)
 108                 cmd |= PCI_COMMAND_MEMORY;
 109         if (cmd != old_cmd) {
 110                 printk(KERN_INFO "PCI: Enabling device %s (%04x -> %04x)\n",
 111                        pci_name(dev), old_cmd, cmd);
 112                 pci_write_config_word(dev, PCI_COMMAND, cmd);
 113         }
 114         return 0;
 115 }
 116
 117 /*
 118  *  If we set up a device for bus mastering, we need to check and set
 119  *  the latency timer as it may not be properly set.
 120  */
 121 static unsigned int pcibios_max_latency = 255;
 122
 123 void pcibios_set_master(struct pci_dev *dev)
 124 {
 125         u8 lat;
 126         pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
 127         if (lat < 16)
 128                 lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
 129         else if (lat > pcibios_max_latency)
 130                 lat = pcibios_max_latency;
 131         else
 132                 return;
 133         printk(KERN_INFO "PCI: Setting latency timer of device %s to %d\n",
 134                pci_name(dev), lat);
 135         pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
 136 }
 137
 138 void __init pcibios_update_irq(struct pci_dev *dev, int irq)
 139 {
 140         pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
 141 }
 142
 143 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 144 {
 145         resource_size_t start = pci_resource_start(dev, bar);
 146         resource_size_t len = pci_resource_len(dev, bar);
 147         unsigned long flags = pci_resource_flags(dev, bar);
 148
 149         if (unlikely(!len || !start))
 150                 return NULL;
 151         if (maxlen && len > maxlen)
 152                 len = maxlen;
 153
 154         /*
 155          * Presently the IORESOURCE_MEM case is a bit special, most
 156          * SH7751 style PCI controllers have PCI memory at a fixed
 157          * location in the address space where no remapping is desired
 158          * (typically at 0xfd000000, but is_pci_memaddr() will know
 159          * best). With the IORESOURCE_MEM case more care has to be taken
 160          * to inhibit page table mapping for legacy cores, but this is
 161          * punted off to __ioremap().
 162          *                                      -- PFM.
 163          */
 164         if (flags & IORESOURCE_IO)
 165                 return ioport_map(start, len);
 166         if (flags & IORESOURCE_MEM)
 167                 return ioremap(start, len);
 168
 169         return NULL;
 170 }
 171 EXPORT_SYMBOL(pci_iomap);
 172
 173 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
 174 {
 175         iounmap(addr);
 176 }
 177 EXPORT_SYMBOL(pci_iounmap);