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 #include <linux/vt.h>
  41
  42 #include <asm/io.h>
  43
  44 #include <asm/sibyte/sb1250_defs.h>
  45 #include <asm/sibyte/sb1250_regs.h>
  46 #include <asm/sibyte/sb1250_scd.h>
  47 #include <asm/sibyte/board.h>
  48
  49 /*
  50  * Macros for calculating offsets into config space given a device
  51  * structure or dev/fun/reg
  52  */
  53 #define CFGOFFSET(bus, devfn, where) (((bus)<<16) + ((devfn)<<8) + (where))
  54 #define CFGADDR(bus, devfn, where)   CFGOFFSET((bus)->number, (devfn), where)
  55
  56 static void *cfg_space;
  57
  58 #define PCI_BUS_ENABLED 1
  59 #define LDT_BUS_ENABLED 2
  60 #define PCI_DEVICE_MODE 4
  61
  62 static int sb1250_bus_status;
  63
  64 #define PCI_BRIDGE_DEVICE  0
  65 #define LDT_BRIDGE_DEVICE  1
  66
  67 #ifdef CONFIG_SIBYTE_HAS_LDT
  68 /*
  69  * HT's level-sensitive interrupts require EOI, which is generated
  70  * through a 4MB memory-mapped region
  71  */
  72 unsigned long ldt_eoi_space;
  73 #endif
  74
  75 /*
  76  * Read/write 32-bit values in config space.
  77  */
  78 static inline u32 READCFG32(u32 addr)
  79 {
  80         return *(u32 *) (cfg_space + (addr & ~3));
  81 }
  82
  83 static inline void WRITECFG32(u32 addr, u32 data)
  84 {
  85         *(u32 *) (cfg_space + (addr & ~3)) = data;
  86 }
  87
  88 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
  89 {
  90         return dev->irq;
  91 }
  92
  93 /* Do platform specific device initialization at pci_enable_device() time */
  94 int pcibios_plat_dev_init(struct pci_dev *dev)
  95 {
  96         return 0;
  97 }
  98
  99 /*
 100  * Some checks before doing config cycles:
 101  * In PCI Device Mode, hide everything on bus 0 except the LDT host
 102  * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
 103  */
 104 static int sb1250_pci_can_access(struct pci_bus *bus, int devfn)
 105 {
 106         u32 devno;
 107
 108         if (!(sb1250_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
 109                 return 0;
 110
 111         if (bus->number == 0) {
 112                 devno = PCI_SLOT(devfn);
 113                 if (devno == LDT_BRIDGE_DEVICE)
 114                         return (sb1250_bus_status & LDT_BUS_ENABLED) != 0;
 115                 else if (sb1250_bus_status & PCI_DEVICE_MODE)
 116                         return 0;
 117                 else
 118                         return 1;
 119         } else
 120                 return 1;
 121 }
 122
 123 /*
 124  * Read/write access functions for various sizes of values
 125  * in config space.  Return all 1's for disallowed accesses
 126  * for a kludgy but adequate simulation of master aborts.
 127  */
 128
 129 static int sb1250_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 130                                int where, int size, u32 * val)
 131 {
 132         u32 data = 0;
 133
 134         if ((size == 2) && (where & 1))
 135                 return PCIBIOS_BAD_REGISTER_NUMBER;
 136         else if ((size == 4) && (where & 3))
 137                 return PCIBIOS_BAD_REGISTER_NUMBER;
 138
 139         if (sb1250_pci_can_access(bus, devfn))
 140                 data = READCFG32(CFGADDR(bus, devfn, where));
 141         else
 142                 data = 0xFFFFFFFF;
 143
 144         if (size == 1)
 145                 *val = (data >> ((where & 3) << 3)) & 0xff;
 146         else if (size == 2)
 147                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 148         else
 149                 *val = data;
 150
 151         return PCIBIOS_SUCCESSFUL;
 152 }
 153
 154 static int sb1250_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 155                                 int where, int size, u32 val)
 156 {
 157         u32 cfgaddr = CFGADDR(bus, devfn, where);
 158         u32 data = 0;
 159
 160         if ((size == 2) && (where & 1))
 161                 return PCIBIOS_BAD_REGISTER_NUMBER;
 162         else if ((size == 4) && (where & 3))
 163                 return PCIBIOS_BAD_REGISTER_NUMBER;
 164
 165         if (!sb1250_pci_can_access(bus, devfn))
 166                 return PCIBIOS_BAD_REGISTER_NUMBER;
 167
 168         data = READCFG32(cfgaddr);
 169
 170         if (size == 1)
 171                 data = (data & ~(0xff << ((where & 3) << 3))) |
 172                     (val << ((where & 3) << 3));
 173         else if (size == 2)
 174                 data = (data & ~(0xffff << ((where & 3) << 3))) |
 175                     (val << ((where & 3) << 3));
 176         else
 177                 data = val;
 178
 179         WRITECFG32(cfgaddr, data);
 180
 181         return PCIBIOS_SUCCESSFUL;
 182 }
 183
 184 struct pci_ops sb1250_pci_ops = {
 185         .read   = sb1250_pcibios_read,
 186         .write  = sb1250_pcibios_write,
 187 };
 188
 189 static struct resource sb1250_mem_resource = {
 190         .name   = "SB1250 PCI MEM",
 191         .start  = 0x40000000UL,
 192         .end    = 0x5fffffffUL,
 193         .flags  = IORESOURCE_MEM,
 194 };
 195
 196 static struct resource sb1250_io_resource = {
 197         .name   = "SB1250 PCI I/O",
 198         .start  = 0x00000000UL,
 199         .end    = 0x01ffffffUL,
 200         .flags  = IORESOURCE_IO,
 201 };
 202
 203 struct pci_controller sb1250_controller = {
 204         .pci_ops        = &sb1250_pci_ops,
 205         .mem_resource   = &sb1250_mem_resource,
 206         .io_resource    = &sb1250_io_resource,
 207 };
 208
 209 static int __init sb1250_pcibios_init(void)
 210 {
 211         void __iomem *io_map_base;
 212         uint32_t cmdreg;
 213         uint64_t reg;
 214
 215         /* CFE will assign PCI resources */
 216         pci_set_flags(PCI_PROBE_ONLY);
 217
 218         /* Avoid ISA compat ranges.  */
 219         PCIBIOS_MIN_IO = 0x00008000UL;
 220         PCIBIOS_MIN_MEM = 0x01000000UL;
 221
 222         /* Set I/O resource limits.  */
 223         ioport_resource.end = 0x01ffffffUL;     /* 32MB accessible by sb1250 */
 224         iomem_resource.end = 0xffffffffUL;      /* no HT support yet */
 225
 226         cfg_space =
 227             ioremap(A_PHYS_LDTPCI_CFG_MATCH_BITS, 16 * 1024 * 1024);
 228
 229         /*
 230          * See if the PCI bus has been configured by the firmware.
 231          */
 232         reg = __raw_readq(IOADDR(A_SCD_SYSTEM_CFG));
 233         if (!(reg & M_SYS_PCI_HOST)) {
 234                 sb1250_bus_status |= PCI_DEVICE_MODE;
 235         } else {
 236                 cmdreg =
 237                     READCFG32(CFGOFFSET
 238                               (0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
 239                                PCI_COMMAND));
 240                 if (!(cmdreg & PCI_COMMAND_MASTER)) {
 241                         printk
 242                             ("PCI: Skipping PCI probe.  Bus is not initialized.\n");
 243                         iounmap(cfg_space);
 244                         return 0;
 245                 }
 246                 sb1250_bus_status |= PCI_BUS_ENABLED;
 247         }
 248
 249         /*
 250          * Establish mappings in KSEG2 (kernel virtual) to PCI I/O
 251          * space.  Use "match bytes" policy to make everything look
 252          * little-endian.  So, you need to also set
 253          * CONFIG_SWAP_IO_SPACE, but this is the combination that
 254          * works correctly with most of Linux's drivers.
 255          * XXX ehs: Should this happen in PCI Device mode?
 256          */
 257         io_map_base = ioremap(A_PHYS_LDTPCI_IO_MATCH_BYTES, 1024 * 1024);
 258         sb1250_controller.io_map_base = (unsigned long)io_map_base;
 259         set_io_port_base((unsigned long)io_map_base);
 260
 261 #ifdef CONFIG_SIBYTE_HAS_LDT
 262         /*
 263          * Also check the LDT bridge's enable, just in case we didn't
 264          * initialize that one.
 265          */
 266
 267         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(LDT_BRIDGE_DEVICE, 0),
 268                                      PCI_COMMAND));
 269         if (cmdreg & PCI_COMMAND_MASTER) {
 270                 sb1250_bus_status |= LDT_BUS_ENABLED;
 271
 272                 /*
 273                  * Need bits 23:16 to convey vector number.  Note that
 274                  * this consumes 4MB of kernel-mapped memory
 275                  * (Kseg2/Kseg3) for 32-bit kernel.
 276                  */
 277                 ldt_eoi_space = (unsigned long)
 278                     ioremap(A_PHYS_LDT_SPECIAL_MATCH_BYTES,
 279                             4 * 1024 * 1024);
 280         }
 281 #endif
 282
 283         register_pci_controller(&sb1250_controller);
 284
 285 #ifdef CONFIG_VGA_CONSOLE
 286         console_lock();
 287         do_take_over_console(&vga_con, 0, MAX_NR_CONSOLES - 1, 1);
 288         console_unlock();
 289 #endif
 290         return 0;
 291 }
 292 arch_initcall(sb1250_pcibios_init);