LXR linux/arch/mips/pci/ops-loongson2.c

   1/*
   2 * Copyright (C) 1999, 2000, 2004  MIPS Technologies, Inc.
   3 *      All rights reserved.
   4 *      Authors: Carsten Langgaard <carstenl@mips.com>
   5 *               Maciej W. Rozycki <macro@mips.com>
   6 *
   7 * Copyright (C) 2009 Lemote Inc.
   8 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
   9 *
  10 *  This program is free software; you can distribute it and/or modify it
  11 *  under the terms of the GNU General Public License (Version 2) as
  12 *  published by the Free Software Foundation.
  13 */
  14#include <linux/types.h>
  15#include <linux/pci.h>
  16#include <linux/kernel.h>
  17#include <linux/init.h>
  18
  19#include <loongson.h>
  20
  21#ifdef CONFIG_CS5536
  22#include <cs5536/cs5536_pci.h>
  23#include <cs5536/cs5536.h>
  24#endif
  25
  26#define PCI_ACCESS_READ  0
  27#define PCI_ACCESS_WRITE 1
  28
  29#define CFG_SPACE_REG(offset) \
  30        (void *)CKSEG1ADDR(LOONGSON_PCICFG_BASE | (offset))
  31#define ID_SEL_BEGIN 11
  32#define MAX_DEV_NUM (31 - ID_SEL_BEGIN)
  33
  34
  35static int loongson_pcibios_config_access(unsigned char access_type,
  36                                      struct pci_bus *bus,
  37                                      unsigned int devfn, int where,
  38                                      u32 *data)
  39{
  40        u32 busnum = bus->number;
  41        u32 addr, type;
  42        u32 dummy;
  43        void *addrp;
  44        int device = PCI_SLOT(devfn);
  45        int function = PCI_FUNC(devfn);
  46        int reg = where & ~3;
  47
  48        if (busnum == 0) {
  49                /* board-specific part,currently,only fuloong2f,yeeloong2f
  50                 * use CS5536, fuloong2e use via686b, gdium has no
  51                 * south bridge
  52                 */
  53#ifdef CONFIG_CS5536
  54                /* cs5536_pci_conf_read4/write4() will call _rdmsr/_wrmsr() to
  55                 * access the regsters PCI_MSR_ADDR, PCI_MSR_DATA_LO,
  56                 * PCI_MSR_DATA_HI, which is bigger than PCI_MSR_CTRL, so, it
  57                 * will not go this branch, but the others. so, no calling dead
  58                 * loop here.
  59                 */
  60                if ((PCI_IDSEL_CS5536 == device) && (reg < PCI_MSR_CTRL)) {
  61                        switch (access_type) {
  62                        case PCI_ACCESS_READ:
  63                                *data = cs5536_pci_conf_read4(function, reg);
  64                                break;
  65                        case PCI_ACCESS_WRITE:
  66                                cs5536_pci_conf_write4(function, reg, *data);
  67                                break;
  68                        }
  69                        return 0;
  70                }
  71#endif
  72                /* Type 0 configuration for onboard PCI bus */
  73                if (device > MAX_DEV_NUM)
  74                        return -1;
  75
  76                addr = (1 << (device + ID_SEL_BEGIN)) | (function << 8) | reg;
  77                type = 0;
  78        } else {
  79                /* Type 1 configuration for offboard PCI bus */
  80                addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
  81                type = 0x10000;
  82        }
  83
  84        /* Clear aborts */
  85        LOONGSON_PCICMD |= LOONGSON_PCICMD_MABORT_CLR | \
  86                                LOONGSON_PCICMD_MTABORT_CLR;
  87
  88        LOONGSON_PCIMAP_CFG = (addr >> 16) | type;
  89
  90        /* Flush Bonito register block */
  91        dummy = LOONGSON_PCIMAP_CFG;
  92        mmiowb();
  93
  94        addrp = CFG_SPACE_REG(addr & 0xffff);
  95        if (access_type == PCI_ACCESS_WRITE)
  96                writel(cpu_to_le32(*data), addrp);
  97        else
  98                *data = le32_to_cpu(readl(addrp));
  99
 100        /* Detect Master/Target abort */
 101        if (LOONGSON_PCICMD & (LOONGSON_PCICMD_MABORT_CLR |
 102                             LOONGSON_PCICMD_MTABORT_CLR)) {
 103                /* Error occurred */
 104
 105                /* Clear bits */
 106                LOONGSON_PCICMD |= (LOONGSON_PCICMD_MABORT_CLR |
 107                                  LOONGSON_PCICMD_MTABORT_CLR);
 108
 109                return -1;
 110        }
 111
 112        return 0;
 113
 114}
 115
 116
 117/*
 118 * We can't address 8 and 16 bit words directly.  Instead we have to
 119 * read/write a 32bit word and mask/modify the data we actually want.
 120 */
 121static int loongson_pcibios_read(struct pci_bus *bus, unsigned int devfn,
 122                             int where, int size, u32 *val)
 123{
 124        u32 data = 0;
 125
 126        if ((size == 2) && (where & 1))
 127                return PCIBIOS_BAD_REGISTER_NUMBER;
 128        else if ((size == 4) && (where & 3))
 129                return PCIBIOS_BAD_REGISTER_NUMBER;
 130
 131        if (loongson_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
 132                                       &data))
 133                return -1;
 134
 135        if (size == 1)
 136                *val = (data >> ((where & 3) << 3)) & 0xff;
 137        else if (size == 2)
 138                *val = (data >> ((where & 3) << 3)) & 0xffff;
 139        else
 140                *val = data;
 141
 142        return PCIBIOS_SUCCESSFUL;
 143}
 144
 145static int loongson_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 146                              int where, int size, u32 val)
 147{
 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 (size == 4)
 156                data = val;
 157        else {
 158                if (loongson_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
 159                                        where, &data))
 160                        return -1;
 161
 162                if (size == 1)
 163                        data = (data & ~(0xff << ((where & 3) << 3))) |
 164                                (val << ((where & 3) << 3));
 165                else if (size == 2)
 166                        data = (data & ~(0xffff << ((where & 3) << 3))) |
 167                                (val << ((where & 3) << 3));
 168        }
 169
 170        if (loongson_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
 171                                       &data))
 172                return -1;
 173
 174        return PCIBIOS_SUCCESSFUL;
 175}
 176
 177struct pci_ops loongson_pci_ops = {
 178        .read = loongson_pcibios_read,
 179        .write = loongson_pcibios_write
 180};
 181
 182#ifdef CONFIG_CS5536
 183DEFINE_RAW_SPINLOCK(msr_lock);
 184
 185void _rdmsr(u32 msr, u32 *hi, u32 *lo)
 186{
 187        struct pci_bus bus = {
 188                .number = PCI_BUS_CS5536
 189        };
 190        u32 devfn = PCI_DEVFN(PCI_IDSEL_CS5536, 0);
 191        unsigned long flags;
 192
 193        raw_spin_lock_irqsave(&msr_lock, flags);
 194        loongson_pcibios_write(&bus, devfn, PCI_MSR_ADDR, 4, msr);
 195        loongson_pcibios_read(&bus, devfn, PCI_MSR_DATA_LO, 4, lo);
 196        loongson_pcibios_read(&bus, devfn, PCI_MSR_DATA_HI, 4, hi);
 197        raw_spin_unlock_irqrestore(&msr_lock, flags);
 198}
 199EXPORT_SYMBOL(_rdmsr);
 200
 201void _wrmsr(u32 msr, u32 hi, u32 lo)
 202{
 203        struct pci_bus bus = {
 204                .number = PCI_BUS_CS5536
 205        };
 206        u32 devfn = PCI_DEVFN(PCI_IDSEL_CS5536, 0);
 207        unsigned long flags;
 208
 209        raw_spin_lock_irqsave(&msr_lock, flags);
 210        loongson_pcibios_write(&bus, devfn, PCI_MSR_ADDR, 4, msr);
 211        loongson_pcibios_write(&bus, devfn, PCI_MSR_DATA_LO, 4, lo);
 212        loongson_pcibios_write(&bus, devfn, PCI_MSR_DATA_HI, 4, hi);
 213        raw_spin_unlock_irqrestore(&msr_lock, flags);
 214}
 215EXPORT_SYMBOL(_wrmsr);
 216#endif
 217