arch/mips/pci/pci-bcm1480ht.c

   1 /*
   2  * Copyright (C) 2001,2002,2005 Broadcom Corporation
   3  * Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18  */
  19
  20 /*
  21  * BCM1480/1455-specific HT support (looking like PCI)
  22  *
  23  * This module provides the glue between Linux's PCI subsystem
  24  * and the hardware.  We basically provide glue for accessing
  25  * configuration space, and set up the translation for I/O
  26  * space accesses.
  27  *
  28  * To access configuration space, we use ioremap.  In the 32-bit
  29  * kernel, this consumes either 4 or 8 page table pages, and 16MB of
  30  * kernel mapped memory.  Hopefully neither of these should be a huge
  31  * problem.
  32  *
  33  */
  34 #include <linux/types.h>
  35 #include <linux/pci.h>
  36 #include <linux/kernel.h>
  37 #include <linux/init.h>
  38 #include <linux/mm.h>
  39 #include <linux/console.h>
  40 #include <linux/tty.h>
  41
  42 #include <asm/sibyte/bcm1480_regs.h>
  43 #include <asm/sibyte/bcm1480_scd.h>
  44 #include <asm/sibyte/board.h>
  45 #include <asm/io.h>
  46
  47 /*
  48  * Macros for calculating offsets into config space given a device
  49  * structure or dev/fun/reg
  50  */
  51 #define CFGOFFSET(bus,devfn,where) (((bus)<<16)+((devfn)<<8)+(where))
  52 #define CFGADDR(bus,devfn,where)   CFGOFFSET((bus)->number,(devfn),where)
  53
  54 static void *ht_cfg_space;
  55
  56 #define PCI_BUS_ENABLED 1
  57 #define PCI_DEVICE_MODE 2
  58
  59 static int bcm1480ht_bus_status = 0;
  60
  61 #define PCI_BRIDGE_DEVICE  0
  62 #define HT_BRIDGE_DEVICE   1
  63
  64 /*
  65  * HT's level-sensitive interrupts require EOI, which is generated
  66  * through a 4MB memory-mapped region
  67  */
  68 unsigned long ht_eoi_space;
  69
  70 /*
  71  * Read/write 32-bit values in config space.
  72  */
  73 static inline u32 READCFG32(u32 addr)
  74 {
  75         return *(u32 *)(ht_cfg_space + (addr&~3));
  76 }
  77
  78 static inline void WRITECFG32(u32 addr, u32 data)
  79 {
  80         *(u32 *)(ht_cfg_space + (addr & ~3)) = data;
  81 }
  82
  83 /*
  84  * Some checks before doing config cycles:
  85  * In PCI Device Mode, hide everything on bus 0 except the LDT host
  86  * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
  87  */
  88 static int bcm1480ht_can_access(struct pci_bus *bus, int devfn)
  89 {
  90         u32 devno;
  91
  92         if (!(bcm1480ht_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
  93                 return 0;
  94
  95         if (bus->number == 0) {
  96                 devno = PCI_SLOT(devfn);
  97                 if (bcm1480ht_bus_status & PCI_DEVICE_MODE)
  98                         return 0;
  99         }
 100         return 1;
 101 }
 102
 103 /*
 104  * Read/write access functions for various sizes of values
 105  * in config space.  Return all 1's for disallowed accesses
 106  * for a kludgy but adequate simulation of master aborts.
 107  */
 108
 109 static int bcm1480ht_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 110                                   int where, int size, u32 * val)
 111 {
 112         u32 data = 0;
 113
 114         if ((size == 2) && (where & 1))
 115                 return PCIBIOS_BAD_REGISTER_NUMBER;
 116         else if ((size == 4) && (where & 3))
 117                 return PCIBIOS_BAD_REGISTER_NUMBER;
 118
 119         if (bcm1480ht_can_access(bus, devfn))
 120                 data = READCFG32(CFGADDR(bus, devfn, where));
 121         else
 122                 data = 0xFFFFFFFF;
 123
 124         if (size == 1)
 125                 *val = (data >> ((where & 3) << 3)) & 0xff;
 126         else if (size == 2)
 127                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 128         else
 129                 *val = data;
 130
 131         return PCIBIOS_SUCCESSFUL;
 132 }
 133
 134 static int bcm1480ht_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 135                                    int where, int size, u32 val)
 136 {
 137         u32 cfgaddr = CFGADDR(bus, devfn, where);
 138         u32 data = 0;
 139
 140         if ((size == 2) && (where & 1))
 141                 return PCIBIOS_BAD_REGISTER_NUMBER;
 142         else if ((size == 4) && (where & 3))
 143                 return PCIBIOS_BAD_REGISTER_NUMBER;
 144
 145         if (!bcm1480ht_can_access(bus, devfn))
 146                 return PCIBIOS_BAD_REGISTER_NUMBER;
 147
 148         data = READCFG32(cfgaddr);
 149
 150         if (size == 1)
 151                 data = (data & ~(0xff << ((where & 3) << 3))) |
 152                     (val << ((where & 3) << 3));
 153         else if (size == 2)
 154                 data = (data & ~(0xffff << ((where & 3) << 3))) |
 155                     (val << ((where & 3) << 3));
 156         else
 157                 data = val;
 158
 159         WRITECFG32(cfgaddr, data);
 160
 161         return PCIBIOS_SUCCESSFUL;
 162 }
 163
 164 static int bcm1480ht_pcibios_get_busno(void)
 165 {
 166         return 0;
 167 }
 168
 169 struct pci_ops bcm1480ht_pci_ops = {
 170         .read   = bcm1480ht_pcibios_read,
 171         .write  = bcm1480ht_pcibios_write,
 172 };
 173
 174 static struct resource bcm1480ht_mem_resource = {
 175         .name   = "BCM1480 HT MEM",
 176         .start  = 0x40000000UL,
 177         .end    = 0x5fffffffUL,
 178         .flags  = IORESOURCE_MEM,
 179 };
 180
 181 static struct resource bcm1480ht_io_resource = {
 182         .name   = "BCM1480 HT I/O",
 183         .start  = 0x00000000UL,
 184         .end    = 0x01ffffffUL,
 185         .flags  = IORESOURCE_IO,
 186 };
 187
 188 struct pci_controller bcm1480ht_controller = {
 189         .pci_ops        = &bcm1480ht_pci_ops,
 190         .mem_resource   = &bcm1480ht_mem_resource,
 191         .io_resource    = &bcm1480ht_io_resource,
 192         .index          = 1,
 193         .get_busno      = bcm1480ht_pcibios_get_busno,
 194 };
 195
 196 static int __init bcm1480ht_pcibios_init(void)
 197 {
 198         uint32_t cmdreg;
 199
 200         ht_cfg_space = ioremap(A_BCM1480_PHYS_HT_CFG_MATCH_BITS, 16*1024*1024);
 201
 202         /*
 203          * See if the PCI bus has been configured by the firmware.
 204          */
 205         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
 206                                      PCI_COMMAND));
 207         if (!(cmdreg & PCI_COMMAND_MASTER)) {
 208                 printk("HT: Skipping HT probe. Bus is not initialized.\n");
 209                 iounmap(ht_cfg_space);
 210                 return 1; /* XXX */
 211         }
 212         bcm1480ht_bus_status |= PCI_BUS_ENABLED;
 213
 214         ht_eoi_space = (unsigned long)
 215                 ioremap(A_BCM1480_PHYS_HT_SPECIAL_MATCH_BYTES,
 216                         4 * 1024 * 1024);
 217
 218         register_pci_controller(&bcm1480ht_controller);
 219
 220         return 0;
 221 }
 222
 223 arch_initcall(bcm1480ht_pcibios_init);