arch/arm/mach-ixp23xx/pci.c

   1 /*
   2  * arch/arm/mach-ixp23xx/pci.c
   3  *
   4  * PCI routines for IXP23XX based systems
   5  *
   6  * Copyright (c) 2005 MontaVista Software, Inc.
   7  *
   8  * based on original code:
   9  *
  10  * Author: Naeem Afzal <naeem.m.afzal@intel.com>
  11  * Copyright 2002-2005 Intel Corp.
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License as published by the
  15  * Free Software Foundation; either version 2 of the License, or (at your
  16  * option) any later version.
  17  */
  18
  19 #include <linux/sched.h>
  20 #include <linux/kernel.h>
  21 #include <linux/pci.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/mm.h>
  24 #include <linux/init.h>
  25 #include <linux/ioport.h>
  26 #include <linux/slab.h>
  27 #include <linux/delay.h>
  28 #include <linux/io.h>
  29
  30 #include <asm/irq.h>
  31 #include <asm/sizes.h>
  32 #include <asm/system.h>
  33 #include <asm/mach/pci.h>
  34 #include <mach/hardware.h>
  35
  36 extern int (*external_fault) (unsigned long, struct pt_regs *);
  37
  38 static volatile int pci_master_aborts = 0;
  39
  40 #ifdef DEBUG
  41 #define DBG(x...)       printk(x)
  42 #else
  43 #define DBG(x...)
  44 #endif
  45
  46 int clear_master_aborts(void);
  47
  48 static u32
  49 *ixp23xx_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
  50 {
  51         u32 *paddress;
  52
  53         /*
  54          * Must be dword aligned
  55          */
  56         where &= ~3;
  57
  58         /*
  59          * For top bus, generate type 0, else type 1
  60          */
  61         if (!bus_nr) {
  62                 if (PCI_SLOT(devfn) >= 8)
  63                         return 0;
  64
  65                 paddress = (u32 *) (IXP23XX_PCI_CFG0_VIRT
  66                                     | (1 << (PCI_SLOT(devfn) + 16))
  67                                     | (PCI_FUNC(devfn) << 8) | where);
  68         } else {
  69                 paddress = (u32 *) (IXP23XX_PCI_CFG1_VIRT
  70                                     | (bus_nr << 16)
  71                                     | (PCI_SLOT(devfn) << 11)
  72                                     | (PCI_FUNC(devfn) << 8) | where);
  73         }
  74
  75         return paddress;
  76 }
  77
  78 /*
  79  * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
  80  * 0 and 3 are not valid indexes...
  81  */
  82 static u32 bytemask[] = {
  83         /*0*/   0,
  84         /*1*/   0xff,
  85         /*2*/   0xffff,
  86         /*3*/   0,
  87         /*4*/   0xffffffff,
  88 };
  89
  90 static int ixp23xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
  91                                 int where, int size, u32 *value)
  92 {
  93         u32 n;
  94         u32 *addr;
  95
  96         n = where % 4;
  97
  98         DBG("In config_read(%d) %d from dev %d:%d:%d\n", size, where,
  99                 bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn));
 100
 101         addr = ixp23xx_pci_config_addr(bus->number, devfn, where);
 102         if (!addr)
 103                 return PCIBIOS_DEVICE_NOT_FOUND;
 104
 105         pci_master_aborts = 0;
 106         *value = (*addr >> (8*n)) & bytemask[size];
 107         if (pci_master_aborts) {
 108                         pci_master_aborts = 0;
 109                         *value = 0xffffffff;
 110                         return PCIBIOS_DEVICE_NOT_FOUND;
 111                 }
 112
 113         return PCIBIOS_SUCCESSFUL;
 114 }
 115
 116 /*
 117  * We don't do error checking on the address for writes.
 118  * It's assumed that the user checked for the device existing first
 119  * by doing a read first.
 120  */
 121 static int ixp23xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
 122                                         int where, int size, u32 value)
 123 {
 124         u32 mask;
 125         u32 *addr;
 126         u32 temp;
 127
 128         mask = ~(bytemask[size] << ((where % 0x4) * 8));
 129         addr = ixp23xx_pci_config_addr(bus->number, devfn, where);
 130         if (!addr)
 131                 return PCIBIOS_DEVICE_NOT_FOUND;
 132         temp = (u32) (value) << ((where % 0x4) * 8);
 133         *addr = (*addr & mask) | temp;
 134
 135         clear_master_aborts();
 136
 137         return PCIBIOS_SUCCESSFUL;
 138 }
 139
 140 struct pci_ops ixp23xx_pci_ops = {
 141         .read   = ixp23xx_pci_read_config,
 142         .write  = ixp23xx_pci_write_config,
 143 };
 144
 145 struct pci_bus *ixp23xx_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
 146 {
 147         return pci_scan_bus(sysdata->busnr, &ixp23xx_pci_ops, sysdata);
 148 }
 149
 150 int ixp23xx_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 151 {
 152         volatile unsigned long temp;
 153         unsigned long flags;
 154
 155         pci_master_aborts = 1;
 156
 157         local_irq_save(flags);
 158         temp = *IXP23XX_PCI_CONTROL;
 159
 160         /*
 161          * master abort and cmd tgt err
 162          */
 163         if (temp & ((1 << 8) | (1 << 5)))
 164                 *IXP23XX_PCI_CONTROL = temp;
 165
 166         temp = *IXP23XX_PCI_CMDSTAT;
 167
 168         if (temp & (1 << 29))
 169                 *IXP23XX_PCI_CMDSTAT = temp;
 170         local_irq_restore(flags);
 171
 172         /*
 173          * If it was an imprecise abort, then we need to correct the
 174          * return address to be _after_ the instruction.
 175          */
 176         if (fsr & (1 << 10))
 177                 regs->ARM_pc += 4;
 178
 179         return 0;
 180 }
 181
 182 int clear_master_aborts(void)
 183 {
 184         volatile u32 temp;
 185
 186         temp = *IXP23XX_PCI_CONTROL;
 187
 188         /*
 189          * master abort and cmd tgt err
 190          */
 191         if (temp & ((1 << 8) | (1 << 5)))
 192                 *IXP23XX_PCI_CONTROL = temp;
 193
 194         temp = *IXP23XX_PCI_CMDSTAT;
 195
 196         if (temp & (1 << 29))
 197                 *IXP23XX_PCI_CMDSTAT = temp;
 198
 199         return 0;
 200 }
 201
 202 static void __init ixp23xx_pci_common_init(void)
 203 {
 204 #ifdef __ARMEB__
 205         *IXP23XX_PCI_CONTROL |= 0x20000;        /* set I/O swapping */
 206 #endif
 207         /*
 208          * ADDR_31 needs to be clear for PCI memory access to CPP memory
 209          */
 210         *IXP23XX_CPP2XSI_CURR_XFER_REG3 &= ~IXP23XX_CPP2XSI_ADDR_31;
 211         *IXP23XX_CPP2XSI_CURR_XFER_REG3 |= IXP23XX_CPP2XSI_PSH_OFF;
 212
 213         /*
 214          * Select correct memory for PCI inbound transactions
 215          */
 216         if (ixp23xx_cpp_boot()) {
 217                 *IXP23XX_PCI_CPP_ADDR_BITS &= ~(1 << 1);
 218         } else {
 219                 *IXP23XX_PCI_CPP_ADDR_BITS |= (1 << 1);
 220
 221                 /*
 222                  * Enable coherency on A2 silicon.
 223                  */
 224                 if (arch_is_coherent())
 225                         *IXP23XX_CPP2XSI_CURR_XFER_REG3 &= ~IXP23XX_CPP2XSI_COH_OFF;
 226         }
 227 }
 228
 229 void __init ixp23xx_pci_preinit(void)
 230 {
 231         ixp23xx_pci_common_init();
 232
 233         hook_fault_code(16+6, ixp23xx_pci_abort_handler, SIGBUS,
 234                         "PCI config cycle to non-existent device");
 235
 236         *IXP23XX_PCI_ADDR_EXT = 0x0000e000;
 237 }
 238
 239 /*
 240  * Prevent PCI layer from seeing the inbound host-bridge resources
 241  */
 242 static void __devinit pci_fixup_ixp23xx(struct pci_dev *dev)
 243 {
 244         int i;
 245
 246         dev->class &= 0xff;
 247         dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
 248         for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 249                 dev->resource[i].start = 0;
 250                 dev->resource[i].end   = 0;
 251                 dev->resource[i].flags = 0;
 252         }
 253 }
 254 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9002, pci_fixup_ixp23xx);
 255
 256 /*
 257  * IXP2300 systems often have large resource requirements, so we just
 258  * use our own resource space.
 259  */
 260 static struct resource ixp23xx_pci_mem_space = {
 261         .start  = IXP23XX_PCI_MEM_START,
 262         .end    = IXP23XX_PCI_MEM_START + IXP23XX_PCI_MEM_SIZE - 1,
 263         .flags  = IORESOURCE_MEM,
 264         .name   = "PCI Mem Space"
 265 };
 266
 267 static struct resource ixp23xx_pci_io_space = {
 268         .start  = 0x00000100,
 269         .end    = 0x01ffffff,
 270         .flags  = IORESOURCE_IO,
 271         .name   = "PCI I/O Space"
 272 };
 273
 274 int ixp23xx_pci_setup(int nr, struct pci_sys_data *sys)
 275 {
 276         if (nr >= 1)
 277                 return 0;
 278
 279         sys->resource[0] = &ixp23xx_pci_io_space;
 280         sys->resource[1] = &ixp23xx_pci_mem_space;
 281         sys->resource[2] = NULL;
 282
 283         return 1;
 284 }
 285
 286 void __init ixp23xx_pci_slave_init(void)
 287 {
 288         ixp23xx_pci_common_init();
 289 }