arch/mips/pci/pci-sb1250.c

   1 /*
   2  * Copyright (C) 2001,2002,2003 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  * BCM1250-specific PCI support
  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 #include <linux/types.h>
  34 #include <linux/pci.h>
  35 #include <linux/kernel.h>
  36 #include <linux/init.h>
  37 #include <linux/mm.h>
  38 #include <linux/console.h>
  39 #include <linux/tty.h>
  40
  41 #include <asm/io.h>
  42
  43 #include <asm/sibyte/sb1250_defs.h>
  44 #include <asm/sibyte/sb1250_regs.h>
  45 #include <asm/sibyte/sb1250_scd.h>
  46 #include <asm/sibyte/board.h>
  47
  48 /*
  49  * Macros for calculating offsets into config space given a device
  50  * structure or dev/fun/reg
  51  */
  52 #define CFGOFFSET(bus, devfn, where) (((bus)<<16) + ((devfn)<<8) + (where))
  53 #define CFGADDR(bus, devfn, where)   CFGOFFSET((bus)->number, (devfn), where)
  54
  55 static void *cfg_space;
  56
  57 #define PCI_BUS_ENABLED 1
  58 #define LDT_BUS_ENABLED 2
  59 #define PCI_DEVICE_MODE 4
  60
  61 static int sb1250_bus_status;
  62
  63 #define PCI_BRIDGE_DEVICE  0
  64 #define LDT_BRIDGE_DEVICE  1
  65
  66 #ifdef CONFIG_SIBYTE_HAS_LDT
  67 /*
  68  * HT's level-sensitive interrupts require EOI, which is generated
  69  * through a 4MB memory-mapped region
  70  */
  71 unsigned long ldt_eoi_space;
  72 #endif
  73
  74 /*
  75  * Read/write 32-bit values in config space.
  76  */
  77 static inline u32 READCFG32(u32 addr)
  78 {
  79         return *(u32 *) (cfg_space + (addr & ~3));
  80 }
  81
  82 static inline void WRITECFG32(u32 addr, u32 data)
  83 {
  84         *(u32 *) (cfg_space + (addr & ~3)) = data;
  85 }
  86
  87 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
  88 {
  89         return dev->irq;
  90 }
  91
  92 /* Do platform specific device initialization at pci_enable_device() time */
  93 int pcibios_plat_dev_init(struct pci_dev *dev)
  94 {
  95         return 0;
  96 }
  97
  98 /*
  99  * Some checks before doing config cycles:
 100  * In PCI Device Mode, hide everything on bus 0 except the LDT host
 101  * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
 102  */
 103 static int sb1250_pci_can_access(struct pci_bus *bus, int devfn)
 104 {
 105         u32 devno;
 106
 107         if (!(sb1250_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
 108                 return 0;
 109
 110         if (bus->number == 0) {
 111                 devno = PCI_SLOT(devfn);
 112                 if (devno == LDT_BRIDGE_DEVICE)
 113                         return (sb1250_bus_status & LDT_BUS_ENABLED) != 0;
 114                 else if (sb1250_bus_status & PCI_DEVICE_MODE)
 115                         return 0;
 116                 else
 117                         return 1;
 118         } else
 119                 return 1;
 120 }
 121
 122 /*
 123  * Read/write access functions for various sizes of values
 124  * in config space.  Return all 1's for disallowed accesses
 125  * for a kludgy but adequate simulation of master aborts.
 126  */
 127
 128 static int sb1250_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 129                                int where, int size, u32 * val)
 130 {
 131         u32 data = 0;
 132
 133         if ((size == 2) && (where & 1))
 134                 return PCIBIOS_BAD_REGISTER_NUMBER;
 135         else if ((size == 4) && (where & 3))
 136                 return PCIBIOS_BAD_REGISTER_NUMBER;
 137
 138         if (sb1250_pci_can_access(bus, devfn))
 139                 data = READCFG32(CFGADDR(bus, devfn, where));
 140         else
 141                 data = 0xFFFFFFFF;
 142
 143         if (size == 1)
 144                 *val = (data >> ((where & 3) << 3)) & 0xff;
 145         else if (size == 2)
 146                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 147         else
 148                 *val = data;
 149
 150         return PCIBIOS_SUCCESSFUL;
 151 }
 152
 153 static int sb1250_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 154                                 int where, int size, u32 val)
 155 {
 156         u32 cfgaddr = CFGADDR(bus, devfn, where);
 157         u32 data = 0;
 158
 159         if ((size == 2) && (where & 1))
 160                 return PCIBIOS_BAD_REGISTER_NUMBER;
 161         else if ((size == 4) && (where & 3))
 162                 return PCIBIOS_BAD_REGISTER_NUMBER;
 163
 164         if (!sb1250_pci_can_access(bus, devfn))
 165                 return PCIBIOS_BAD_REGISTER_NUMBER;
 166
 167         data = READCFG32(cfgaddr);
 168
 169         if (size == 1)
 170                 data = (data & ~(0xff << ((where & 3) << 3))) |
 171                     (val << ((where & 3) << 3));
 172         else if (size == 2)
 173                 data = (data & ~(0xffff << ((where & 3) << 3))) |
 174                     (val << ((where & 3) << 3));
 175         else
 176                 data = val;
 177
 178         WRITECFG32(cfgaddr, data);
 179
 180         return PCIBIOS_SUCCESSFUL;
 181 }
 182
 183 struct pci_ops sb1250_pci_ops = {
 184         .read   = sb1250_pcibios_read,
 185         .write  = sb1250_pcibios_write,
 186 };
 187
 188 static struct resource sb1250_mem_resource = {
 189         .name   = "SB1250 PCI MEM",
 190         .start  = 0x40000000UL,
 191         .end    = 0x5fffffffUL,
 192         .flags  = IORESOURCE_MEM,
 193 };
 194
 195 static struct resource sb1250_io_resource = {
 196         .name   = "SB1250 PCI I/O",
 197         .start  = 0x00000000UL,
 198         .end    = 0x01ffffffUL,
 199         .flags  = IORESOURCE_IO,
 200 };
 201
 202 struct pci_controller sb1250_controller = {
 203         .pci_ops        = &sb1250_pci_ops,
 204         .mem_resource   = &sb1250_mem_resource,
 205         .io_resource    = &sb1250_io_resource,
 206 };
 207
 208 static int __init sb1250_pcibios_init(void)
 209 {
 210         void __iomem *io_map_base;
 211         uint32_t cmdreg;
 212         uint64_t reg;
 213
 214         /* CFE will assign PCI resources */
 215         pci_probe_only = 1;
 216
 217         /* Avoid ISA compat ranges.  */
 218         PCIBIOS_MIN_IO = 0x00008000UL;
 219         PCIBIOS_MIN_MEM = 0x01000000UL;
 220
 221         /* Set I/O resource limits.  */
 222         ioport_resource.end = 0x01ffffffUL;     /* 32MB accessible by sb1250 */
 223         iomem_resource.end = 0xffffffffUL;      /* no HT support yet */
 224
 225         cfg_space =
 226             ioremap(A_PHYS_LDTPCI_CFG_MATCH_BITS, 16 * 1024 * 1024);
 227
 228         /*
 229          * See if the PCI bus has been configured by the firmware.
 230          */
 231         reg = __raw_readq(IOADDR(A_SCD_SYSTEM_CFG));
 232         if (!(reg & M_SYS_PCI_HOST)) {
 233                 sb1250_bus_status |= PCI_DEVICE_MODE;
 234         } else {
 235                 cmdreg =
 236                     READCFG32(CFGOFFSET
 237                               (0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
 238                                PCI_COMMAND));
 239                 if (!(cmdreg & PCI_COMMAND_MASTER)) {
 240                         printk
 241                             ("PCI: Skipping PCI probe.  Bus is not initialized.\n");
 242                         iounmap(cfg_space);
 243                         return 0;
 244                 }
 245                 sb1250_bus_status |= PCI_BUS_ENABLED;
 246         }
 247
 248         /*
 249          * Establish mappings in KSEG2 (kernel virtual) to PCI I/O
 250          * space.  Use "match bytes" policy to make everything look
 251          * little-endian.  So, you need to also set
 252          * CONFIG_SWAP_IO_SPACE, but this is the combination that
 253          * works correctly with most of Linux's drivers.
 254          * XXX ehs: Should this happen in PCI Device mode?
 255          */
 256         io_map_base = ioremap(A_PHYS_LDTPCI_IO_MATCH_BYTES, 1024 * 1024);
 257         sb1250_controller.io_map_base = io_map_base;
 258         set_io_port_base((unsigned long)io_map_base);
 259
 260 #ifdef CONFIG_SIBYTE_HAS_LDT
 261         /*
 262          * Also check the LDT bridge's enable, just in case we didn't
 263          * initialize that one.
 264          */
 265
 266         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(LDT_BRIDGE_DEVICE, 0),
 267                                      PCI_COMMAND));
 268         if (cmdreg & PCI_COMMAND_MASTER) {
 269                 sb1250_bus_status |= LDT_BUS_ENABLED;
 270
 271                 /*
 272                  * Need bits 23:16 to convey vector number.  Note that
 273                  * this consumes 4MB of kernel-mapped memory
 274                  * (Kseg2/Kseg3) for 32-bit kernel.
 275                  */
 276                 ldt_eoi_space = (unsigned long)
 277                     ioremap(A_PHYS_LDT_SPECIAL_MATCH_BYTES,
 278                             4 * 1024 * 1024);
 279         }
 280 #endif
 281
 282         register_pci_controller(&sb1250_controller);
 283
 284 #ifdef CONFIG_VGA_CONSOLE
 285         take_over_console(&vga_con, 0, MAX_NR_CONSOLES - 1, 1);
 286 #endif
 287         return 0;
 288 }
 289 arch_initcall(sb1250_pcibios_init);