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