arch/mips/pci/pci-bcm1480.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  * BCM1x80/1x55-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  * XXX: AT THIS TIME, ONLY the NATIVE PCI-X INTERFACE IS SUPPORTED.
  34  */
  35 #include <linux/types.h>
  36 #include <linux/pci.h>
  37 #include <linux/kernel.h>
  38 #include <linux/init.h>
  39 #include <linux/mm.h>
  40 #include <linux/console.h>
  41 #include <linux/tty.h>
  42
  43 #include <asm/sibyte/bcm1480_regs.h>
  44 #include <asm/sibyte/bcm1480_scd.h>
  45 #include <asm/sibyte/board.h>
  46 #include <asm/io.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 PCI_DEVICE_MODE 2
  59
  60 static int bcm1480_bus_status = 0;
  61
  62 #define PCI_BRIDGE_DEVICE  0
  63
  64 /*
  65  * Read/write 32-bit values in config space.
  66  */
  67 static inline u32 READCFG32(u32 addr)
  68 {
  69         return *(u32 *)(cfg_space + (addr&~3));
  70 }
  71
  72 static inline void WRITECFG32(u32 addr, u32 data)
  73 {
  74         *(u32 *)(cfg_space + (addr & ~3)) = data;
  75 }
  76
  77 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
  78 {
  79         if (pin == 0)
  80                 return -1;
  81
  82         return K_BCM1480_INT_PCI_INTA - 1 + pin;
  83 }
  84
  85 /* Do platform specific device initialization at pci_enable_device() time */
  86 int pcibios_plat_dev_init(struct pci_dev *dev)
  87 {
  88         return 0;
  89 }
  90
  91 /*
  92  * Some checks before doing config cycles:
  93  * In PCI Device Mode, hide everything on bus 0 except the LDT host
  94  * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
  95  */
  96 static int bcm1480_pci_can_access(struct pci_bus *bus, int devfn)
  97 {
  98         u32 devno;
  99
 100         if (!(bcm1480_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
 101                 return 0;
 102
 103         if (bus->number == 0) {
 104                 devno = PCI_SLOT(devfn);
 105                 if (bcm1480_bus_status & PCI_DEVICE_MODE)
 106                         return 0;
 107                 else
 108                         return 1;
 109         } else
 110                 return 1;
 111 }
 112
 113 /*
 114  * Read/write access functions for various sizes of values
 115  * in config space.  Return all 1's for disallowed accesses
 116  * for a kludgy but adequate simulation of master aborts.
 117  */
 118
 119 static int bcm1480_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 120                                 int where, int size, u32 * val)
 121 {
 122         u32 data = 0;
 123
 124         if ((size == 2) && (where & 1))
 125                 return PCIBIOS_BAD_REGISTER_NUMBER;
 126         else if ((size == 4) && (where & 3))
 127                 return PCIBIOS_BAD_REGISTER_NUMBER;
 128
 129         if (bcm1480_pci_can_access(bus, devfn))
 130                 data = READCFG32(CFGADDR(bus, devfn, where));
 131         else
 132                 data = 0xFFFFFFFF;
 133
 134         if (size == 1)
 135                 *val = (data >> ((where & 3) << 3)) & 0xff;
 136         else if (size == 2)
 137                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 138         else
 139                 *val = data;
 140
 141         return PCIBIOS_SUCCESSFUL;
 142 }
 143
 144 static int bcm1480_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 145                                 int where, int size, u32 val)
 146 {
 147         u32 cfgaddr = CFGADDR(bus, devfn, where);
 148         u32 data = 0;
 149
 150         if ((size == 2) && (where & 1))
 151                 return PCIBIOS_BAD_REGISTER_NUMBER;
 152         else if ((size == 4) && (where & 3))
 153                 return PCIBIOS_BAD_REGISTER_NUMBER;
 154
 155         if (!bcm1480_pci_can_access(bus, devfn))
 156                 return PCIBIOS_BAD_REGISTER_NUMBER;
 157
 158         data = READCFG32(cfgaddr);
 159
 160         if (size == 1)
 161                 data = (data & ~(0xff << ((where & 3) << 3))) |
 162                     (val << ((where & 3) << 3));
 163         else if (size == 2)
 164                 data = (data & ~(0xffff << ((where & 3) << 3))) |
 165                     (val << ((where & 3) << 3));
 166         else
 167                 data = val;
 168
 169         WRITECFG32(cfgaddr, data);
 170
 171         return PCIBIOS_SUCCESSFUL;
 172 }
 173
 174 struct pci_ops bcm1480_pci_ops = {
 175         bcm1480_pcibios_read,
 176         bcm1480_pcibios_write,
 177 };
 178
 179 static struct resource bcm1480_mem_resource = {
 180         .name   = "BCM1480 PCI MEM",
 181         .start  = A_BCM1480_PHYS_PCI_MEM_MATCH_BYTES,
 182         .end    = A_BCM1480_PHYS_PCI_MEM_MATCH_BYTES + 0xfffffffUL,
 183         .flags  = IORESOURCE_MEM,
 184 };
 185
 186 static struct resource bcm1480_io_resource = {
 187         .name   = "BCM1480 PCI I/O",
 188         .start  = 0x2c000000UL,
 189         .end    = 0x2dffffffUL,
 190         .flags  = IORESOURCE_IO,
 191 };
 192
 193 struct pci_controller bcm1480_controller = {
 194         .pci_ops        = &bcm1480_pci_ops,
 195         .mem_resource   = &bcm1480_mem_resource,
 196         .io_resource    = &bcm1480_io_resource,
 197 };
 198
 199
 200 static int __init bcm1480_pcibios_init(void)
 201 {
 202         uint32_t cmdreg;
 203         uint64_t reg;
 204         extern int pci_probe_only;
 205
 206         /* CFE will assign PCI resources */
 207         pci_probe_only = 1;
 208
 209         /* Avoid ISA compat ranges.  */
 210         PCIBIOS_MIN_IO = 0x00008000UL;
 211         PCIBIOS_MIN_MEM = 0x01000000UL;
 212
 213         /* Set I/O resource limits. - unlimited for now to accomodate HT */
 214         ioport_resource.end = 0xffffffffUL;
 215         iomem_resource.end = 0xffffffffUL;
 216
 217         cfg_space = ioremap(A_BCM1480_PHYS_PCI_CFG_MATCH_BITS, 16*1024*1024);
 218
 219         /*
 220          * See if the PCI bus has been configured by the firmware.
 221          */
 222         reg = __raw_readq(IOADDR(A_SCD_SYSTEM_CFG));
 223         if (!(reg & M_BCM1480_SYS_PCI_HOST)) {
 224                 bcm1480_bus_status |= PCI_DEVICE_MODE;
 225         } else {
 226                 cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
 227                                              PCI_COMMAND));
 228                 if (!(cmdreg & PCI_COMMAND_MASTER)) {
 229                         printk
 230                             ("PCI: Skipping PCI probe.  Bus is not initialized.\n");
 231                         iounmap(cfg_space);
 232                         return 1; /* XXX */
 233                 }
 234                 bcm1480_bus_status |= PCI_BUS_ENABLED;
 235         }
 236
 237         /* turn on ExpMemEn */
 238         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40));
 239         WRITECFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40),
 240                         cmdreg | 0x10);
 241         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40));
 242
 243         /*
 244          * Establish mappings in KSEG2 (kernel virtual) to PCI I/O
 245          * space.  Use "match bytes" policy to make everything look
 246          * little-endian.  So, you need to also set
 247          * CONFIG_SWAP_IO_SPACE, but this is the combination that
 248          * works correctly with most of Linux's drivers.
 249          * XXX ehs: Should this happen in PCI Device mode?
 250          */
 251
 252         set_io_port_base((unsigned long)
 253                 ioremap(A_BCM1480_PHYS_PCI_IO_MATCH_BYTES, 65536));
 254         isa_slot_offset = (unsigned long)
 255                 ioremap(A_BCM1480_PHYS_PCI_MEM_MATCH_BYTES, 1024*1024);
 256
 257         register_pci_controller(&bcm1480_controller);
 258
 259 #ifdef CONFIG_VGA_CONSOLE
 260         take_over_console(&vga_con, 0, MAX_NR_CONSOLES-1, 1);
 261 #endif
 262         return 0;
 263 }
 264
 265 arch_initcall(bcm1480_pcibios_init);