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/config.h>
  36 #include <linux/types.h>
  37 #include <linux/pci.h>
  38 #include <linux/kernel.h>
  39 #include <linux/init.h>
  40 #include <linux/mm.h>
  41 #include <linux/console.h>
  42 #include <linux/tty.h>
  43
  44 #include <asm/sibyte/bcm1480_regs.h>
  45 #include <asm/sibyte/bcm1480_scd.h>
  46 #include <asm/sibyte/board.h>
  47 #include <asm/io.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 PCI_DEVICE_MODE 2
  60
  61 static int bcm1480_bus_status = 0;
  62
  63 #define PCI_BRIDGE_DEVICE  0
  64
  65 /*
  66  * Read/write 32-bit values in config space.
  67  */
  68 static inline u32 READCFG32(u32 addr)
  69 {
  70         return *(u32 *)(cfg_space + (addr&~3));
  71 }
  72
  73 static inline void WRITECFG32(u32 addr, u32 data)
  74 {
  75         *(u32 *)(cfg_space + (addr & ~3)) = data;
  76 }
  77
  78 int pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
  79 {
  80         return dev->irq;
  81 }
  82
  83 /* Do platform specific device initialization at pci_enable_device() time */
  84 int pcibios_plat_dev_init(struct pci_dev *dev)
  85 {
  86         return 0;
  87 }
  88
  89 /*
  90  * Some checks before doing config cycles:
  91  * In PCI Device Mode, hide everything on bus 0 except the LDT host
  92  * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
  93  */
  94 static int bcm1480_pci_can_access(struct pci_bus *bus, int devfn)
  95 {
  96         u32 devno;
  97
  98         if (!(bcm1480_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
  99                 return 0;
 100
 101         if (bus->number == 0) {
 102                 devno = PCI_SLOT(devfn);
 103                 if (bcm1480_bus_status & PCI_DEVICE_MODE)
 104                         return 0;
 105                 else
 106                         return 1;
 107         } else
 108                 return 1;
 109 }
 110
 111 /*
 112  * Read/write access functions for various sizes of values
 113  * in config space.  Return all 1's for disallowed accesses
 114  * for a kludgy but adequate simulation of master aborts.
 115  */
 116
 117 static int bcm1480_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 118                                 int where, int size, u32 * val)
 119 {
 120         u32 data = 0;
 121
 122         if ((size == 2) && (where & 1))
 123                 return PCIBIOS_BAD_REGISTER_NUMBER;
 124         else if ((size == 4) && (where & 3))
 125                 return PCIBIOS_BAD_REGISTER_NUMBER;
 126
 127         if (bcm1480_pci_can_access(bus, devfn))
 128                 data = READCFG32(CFGADDR(bus, devfn, where));
 129         else
 130                 data = 0xFFFFFFFF;
 131
 132         if (size == 1)
 133                 *val = (data >> ((where & 3) << 3)) & 0xff;
 134         else if (size == 2)
 135                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 136         else
 137                 *val = data;
 138
 139         return PCIBIOS_SUCCESSFUL;
 140 }
 141
 142 static int bcm1480_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 143                                 int where, int size, u32 val)
 144 {
 145         u32 cfgaddr = CFGADDR(bus, devfn, where);
 146         u32 data = 0;
 147
 148         if ((size == 2) && (where & 1))
 149                 return PCIBIOS_BAD_REGISTER_NUMBER;
 150         else if ((size == 4) && (where & 3))
 151                 return PCIBIOS_BAD_REGISTER_NUMBER;
 152
 153         if (!bcm1480_pci_can_access(bus, devfn))
 154                 return PCIBIOS_BAD_REGISTER_NUMBER;
 155
 156         data = READCFG32(cfgaddr);
 157
 158         if (size == 1)
 159                 data = (data & ~(0xff << ((where & 3) << 3))) |
 160                     (val << ((where & 3) << 3));
 161         else if (size == 2)
 162                 data = (data & ~(0xffff << ((where & 3) << 3))) |
 163                     (val << ((where & 3) << 3));
 164         else
 165                 data = val;
 166
 167         WRITECFG32(cfgaddr, data);
 168
 169         return PCIBIOS_SUCCESSFUL;
 170 }
 171
 172 struct pci_ops bcm1480_pci_ops = {
 173         bcm1480_pcibios_read,
 174         bcm1480_pcibios_write,
 175 };
 176
 177 static struct resource bcm1480_mem_resource = {
 178         .name   = "BCM1480 PCI MEM",
 179         .start  = 0x30000000UL,
 180         .end    = 0x3fffffffUL,
 181         .flags  = IORESOURCE_MEM,
 182 };
 183
 184 static struct resource bcm1480_io_resource = {
 185         .name   = "BCM1480 PCI I/O",
 186         .start  = 0x2c000000UL,
 187         .end    = 0x2dffffffUL,
 188         .flags  = IORESOURCE_IO,
 189 };
 190
 191 struct pci_controller bcm1480_controller = {
 192         .pci_ops        = &bcm1480_pci_ops,
 193         .mem_resource   = &bcm1480_mem_resource,
 194         .io_resource    = &bcm1480_io_resource,
 195 };
 196
 197
 198 static int __init bcm1480_pcibios_init(void)
 199 {
 200         uint32_t cmdreg;
 201         uint64_t reg;
 202         extern int pci_probe_only;
 203
 204         /* CFE will assign PCI resources */
 205         pci_probe_only = 1;
 206
 207         /* Avoid ISA compat ranges.  */
 208         PCIBIOS_MIN_IO = 0x00008000UL;
 209         PCIBIOS_MIN_MEM = 0x01000000UL;
 210
 211         /* Set I/O resource limits. - unlimited for now to accomodate HT */
 212         ioport_resource.end = 0xffffffffUL;
 213         iomem_resource.end = 0xffffffffUL;
 214
 215         cfg_space = ioremap(A_BCM1480_PHYS_PCI_CFG_MATCH_BITS, 16*1024*1024);
 216
 217         /*
 218          * See if the PCI bus has been configured by the firmware.
 219          */
 220         reg = *((volatile uint64_t *) IOADDR(A_SCD_SYSTEM_CFG));
 221         if (!(reg & M_BCM1480_SYS_PCI_HOST)) {
 222                 bcm1480_bus_status |= PCI_DEVICE_MODE;
 223         } else {
 224                 cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
 225                                              PCI_COMMAND));
 226                 if (!(cmdreg & PCI_COMMAND_MASTER)) {
 227                         printk
 228                             ("PCI: Skipping PCI probe.  Bus is not initialized.\n");
 229                         iounmap(cfg_space);
 230                         return 1; /* XXX */
 231                 }
 232                 bcm1480_bus_status |= PCI_BUS_ENABLED;
 233         }
 234
 235         /* turn on ExpMemEn */
 236         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40));
 237         WRITECFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40),
 238                         cmdreg | 0x10);
 239         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40));
 240
 241         /*
 242          * Establish mappings in KSEG2 (kernel virtual) to PCI I/O
 243          * space.  Use "match bytes" policy to make everything look
 244          * little-endian.  So, you need to also set
 245          * CONFIG_SWAP_IO_SPACE, but this is the combination that
 246          * works correctly with most of Linux's drivers.
 247          * XXX ehs: Should this happen in PCI Device mode?
 248          */
 249
 250         set_io_port_base((unsigned long)
 251                 ioremap(A_BCM1480_PHYS_PCI_IO_MATCH_BYTES, 65536));
 252         isa_slot_offset = (unsigned long)
 253                 ioremap(A_BCM1480_PHYS_PCI_MEM_MATCH_BYTES, 1024*1024);
 254
 255         register_pci_controller(&bcm1480_controller);
 256
 257 #ifdef CONFIG_VGA_CONSOLE
 258         take_over_console(&vga_con,0,MAX_NR_CONSOLES-1,1);
 259 #endif
 260         return 0;
 261 }
 262
 263 arch_initcall(bcm1480_pcibios_init);