arch/mips/pci/pci-bcm1480.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2001,2002,2005 Broadcom Corporation
   4  * Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
   5  */
   6
   7 /*
   8  * BCM1x80/1x55-specific PCI support
   9  *
  10  * This module provides the glue between Linux's PCI subsystem
  11  * and the hardware.  We basically provide glue for accessing
  12  * configuration space, and set up the translation for I/O
  13  * space accesses.
  14  *
  15  * To access configuration space, we use ioremap.  In the 32-bit
  16  * kernel, this consumes either 4 or 8 page table pages, and 16MB of
  17  * kernel mapped memory.  Hopefully neither of these should be a huge
  18  * problem.
  19  *
  20  * XXX: AT THIS TIME, ONLY the NATIVE PCI-X INTERFACE IS SUPPORTED.
  21  */
  22 #include <linux/types.h>
  23 #include <linux/pci.h>
  24 #include <linux/kernel.h>
  25 #include <linux/init.h>
  26 #include <linux/mm.h>
  27 #include <linux/console.h>
  28 #include <linux/tty.h>
  29 #include <linux/vt.h>
  30
  31 #include <asm/sibyte/bcm1480_regs.h>
  32 #include <asm/sibyte/bcm1480_scd.h>
  33 #include <asm/sibyte/board.h>
  34 #include <asm/io.h>
  35
  36 /*
  37  * Macros for calculating offsets into config space given a device
  38  * structure or dev/fun/reg
  39  */
  40 #define CFGOFFSET(bus, devfn, where) (((bus)<<16)+((devfn)<<8)+(where))
  41 #define CFGADDR(bus, devfn, where)   CFGOFFSET((bus)->number, (devfn), where)
  42
  43 static void *cfg_space;
  44
  45 #define PCI_BUS_ENABLED 1
  46 #define PCI_DEVICE_MODE 2
  47
  48 static int bcm1480_bus_status;
  49
  50 #define PCI_BRIDGE_DEVICE  0
  51
  52 /*
  53  * Read/write 32-bit values in config space.
  54  */
  55 static inline u32 READCFG32(u32 addr)
  56 {
  57         return *(u32 *)(cfg_space + (addr&~3));
  58 }
  59
  60 static inline void WRITECFG32(u32 addr, u32 data)
  61 {
  62         *(u32 *)(cfg_space + (addr & ~3)) = data;
  63 }
  64
  65 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
  66 {
  67         if (pin == 0)
  68                 return -1;
  69
  70         return K_BCM1480_INT_PCI_INTA - 1 + pin;
  71 }
  72
  73 /* Do platform specific device initialization at pci_enable_device() time */
  74 int pcibios_plat_dev_init(struct pci_dev *dev)
  75 {
  76         return 0;
  77 }
  78
  79 /*
  80  * Some checks before doing config cycles:
  81  * In PCI Device Mode, hide everything on bus 0 except the LDT host
  82  * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
  83  */
  84 static int bcm1480_pci_can_access(struct pci_bus *bus, int devfn)
  85 {
  86         u32 devno;
  87
  88         if (!(bcm1480_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
  89                 return 0;
  90
  91         if (bus->number == 0) {
  92                 devno = PCI_SLOT(devfn);
  93                 if (bcm1480_bus_status & PCI_DEVICE_MODE)
  94                         return 0;
  95                 else
  96                         return 1;
  97         } else
  98                 return 1;
  99 }
 100
 101 /*
 102  * Read/write access functions for various sizes of values
 103  * in config space.  Return all 1's for disallowed accesses
 104  * for a kludgy but adequate simulation of master aborts.
 105  */
 106
 107 static int bcm1480_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 108                                 int where, int size, u32 * val)
 109 {
 110         u32 data = 0;
 111
 112         if ((size == 2) && (where & 1))
 113                 return PCIBIOS_BAD_REGISTER_NUMBER;
 114         else if ((size == 4) && (where & 3))
 115                 return PCIBIOS_BAD_REGISTER_NUMBER;
 116
 117         if (bcm1480_pci_can_access(bus, devfn))
 118                 data = READCFG32(CFGADDR(bus, devfn, where));
 119         else
 120                 data = 0xFFFFFFFF;
 121
 122         if (size == 1)
 123                 *val = (data >> ((where & 3) << 3)) & 0xff;
 124         else if (size == 2)
 125                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 126         else
 127                 *val = data;
 128
 129         return PCIBIOS_SUCCESSFUL;
 130 }
 131
 132 static int bcm1480_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 133                                 int where, int size, u32 val)
 134 {
 135         u32 cfgaddr = CFGADDR(bus, devfn, where);
 136         u32 data = 0;
 137
 138         if ((size == 2) && (where & 1))
 139                 return PCIBIOS_BAD_REGISTER_NUMBER;
 140         else if ((size == 4) && (where & 3))
 141                 return PCIBIOS_BAD_REGISTER_NUMBER;
 142
 143         if (!bcm1480_pci_can_access(bus, devfn))
 144                 return PCIBIOS_BAD_REGISTER_NUMBER;
 145
 146         data = READCFG32(cfgaddr);
 147
 148         if (size == 1)
 149                 data = (data & ~(0xff << ((where & 3) << 3))) |
 150                     (val << ((where & 3) << 3));
 151         else if (size == 2)
 152                 data = (data & ~(0xffff << ((where & 3) << 3))) |
 153                     (val << ((where & 3) << 3));
 154         else
 155                 data = val;
 156
 157         WRITECFG32(cfgaddr, data);
 158
 159         return PCIBIOS_SUCCESSFUL;
 160 }
 161
 162 struct pci_ops bcm1480_pci_ops = {
 163         .read   = bcm1480_pcibios_read,
 164         .write  = bcm1480_pcibios_write,
 165 };
 166
 167 static struct resource bcm1480_mem_resource = {
 168         .name   = "BCM1480 PCI MEM",
 169         .start  = A_BCM1480_PHYS_PCI_MEM_MATCH_BYTES,
 170         .end    = A_BCM1480_PHYS_PCI_MEM_MATCH_BYTES + 0xfffffffUL,
 171         .flags  = IORESOURCE_MEM,
 172 };
 173
 174 static struct resource bcm1480_io_resource = {
 175         .name   = "BCM1480 PCI I/O",
 176         .start  = A_BCM1480_PHYS_PCI_IO_MATCH_BYTES,
 177         .end    = A_BCM1480_PHYS_PCI_IO_MATCH_BYTES + 0x1ffffffUL,
 178         .flags  = IORESOURCE_IO,
 179 };
 180
 181 struct pci_controller bcm1480_controller = {
 182         .pci_ops        = &bcm1480_pci_ops,
 183         .mem_resource   = &bcm1480_mem_resource,
 184         .io_resource    = &bcm1480_io_resource,
 185         .io_offset      = A_BCM1480_PHYS_PCI_IO_MATCH_BYTES,
 186 };
 187
 188
 189 static int __init bcm1480_pcibios_init(void)
 190 {
 191         uint32_t cmdreg;
 192         uint64_t reg;
 193
 194         /* CFE will assign PCI resources */
 195         pci_set_flags(PCI_PROBE_ONLY);
 196
 197         /* Avoid ISA compat ranges.  */
 198         PCIBIOS_MIN_IO = 0x00008000UL;
 199         PCIBIOS_MIN_MEM = 0x01000000UL;
 200
 201         /* Set I/O resource limits. - unlimited for now to accommodate HT */
 202         ioport_resource.end = 0xffffffffUL;
 203         iomem_resource.end = 0xffffffffUL;
 204
 205         cfg_space = ioremap(A_BCM1480_PHYS_PCI_CFG_MATCH_BITS, 16*1024*1024);
 206
 207         /*
 208          * See if the PCI bus has been configured by the firmware.
 209          */
 210         reg = __raw_readq(IOADDR(A_SCD_SYSTEM_CFG));
 211         if (!(reg & M_BCM1480_SYS_PCI_HOST)) {
 212                 bcm1480_bus_status |= PCI_DEVICE_MODE;
 213         } else {
 214                 cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
 215                                              PCI_COMMAND));
 216                 if (!(cmdreg & PCI_COMMAND_MASTER)) {
 217                         printk
 218                             ("PCI: Skipping PCI probe.  Bus is not initialized.\n");
 219                         iounmap(cfg_space);
 220                         return 1; /* XXX */
 221                 }
 222                 bcm1480_bus_status |= PCI_BUS_ENABLED;
 223         }
 224
 225         /* turn on ExpMemEn */
 226         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40));
 227         WRITECFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40),
 228                         cmdreg | 0x10);
 229         cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40));
 230
 231         /*
 232          * Establish mappings in KSEG2 (kernel virtual) to PCI I/O
 233          * space.  Use "match bytes" policy to make everything look
 234          * little-endian.  So, you need to also set
 235          * CONFIG_SWAP_IO_SPACE, but this is the combination that
 236          * works correctly with most of Linux's drivers.
 237          * XXX ehs: Should this happen in PCI Device mode?
 238          */
 239
 240         bcm1480_controller.io_map_base = (unsigned long)
 241                 ioremap(A_BCM1480_PHYS_PCI_IO_MATCH_BYTES, 65536);
 242         bcm1480_controller.io_map_base -= bcm1480_controller.io_offset;
 243         set_io_port_base(bcm1480_controller.io_map_base);
 244
 245         register_pci_controller(&bcm1480_controller);
 246
 247 #ifdef CONFIG_VGA_CONSOLE
 248         console_lock();
 249         do_take_over_console(&vga_con, 0, MAX_NR_CONSOLES-1, 1);
 250         console_unlock();
 251 #endif
 252         return 0;
 253 }
 254
 255 arch_initcall(bcm1480_pcibios_init);