ops-loongson2.c

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/*
 * Copyright (C) 1999, 2000, 2004  MIPS Technologies, Inc.
 *  All rights reserved.
 *  Authors: Carsten Langgaard <[email protected]>
 *       Maciej W. Rozycki <[email protected]>
 *
 * Copyright (C) 2009 Lemote Inc.
 * Author: Wu Zhangjin <[email protected]>
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 */
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/export.h>

#include <loongson.h>

#ifdef CONFIG_CS5536
#include <cs5536/cs5536_pci.h>
#include <cs5536/cs5536.h>
#endif

#define PCI_ACCESS_READ  0
#define PCI_ACCESS_WRITE 1

#define CFG_SPACE_REG(offset) \
    (void *)CKSEG1ADDR(LOONGSON_PCICFG_BASE | (offset))
#define ID_SEL_BEGIN 11
#define MAX_DEV_NUM (31 - ID_SEL_BEGIN)


static int loongson_pcibios_config_access(unsigned char access_type,
                      struct pci_bus *bus,
                      unsigned int devfn, int where,
                      u32 *data)
{
    u32 busnum = bus->number;
    u32 addr, type;
    u32 dummy;
    void *addrp;
    int device = PCI_SLOT(devfn);
    int function = PCI_FUNC(devfn);
    int reg = where & ~3;

    if (busnum == 0) {
        /* board-specific part,currently,only fuloong2f,yeeloong2f
         * use CS5536, fuloong2e use via686b, gdium has no
         * south bridge
         */
#ifdef CONFIG_CS5536
        /* cs5536_pci_conf_read4/write4() will call _rdmsr/_wrmsr() to
         * access the regsters PCI_MSR_ADDR, PCI_MSR_DATA_LO,
         * PCI_MSR_DATA_HI, which is bigger than PCI_MSR_CTRL, so, it
         * will not go this branch, but the others. so, no calling dead
         * loop here.
         */
        if ((PCI_IDSEL_CS5536 == device) && (reg < PCI_MSR_CTRL)) {
            switch (access_type) {
            case PCI_ACCESS_READ:
                *data = cs5536_pci_conf_read4(function, reg);
                break;
            case PCI_ACCESS_WRITE:
                cs5536_pci_conf_write4(function, reg, *data);
                break;
            }
            return 0;
        }
#endif
        /* Type 0 configuration for onboard PCI bus */
        if (device > MAX_DEV_NUM)
            return -1;

        addr = (1 << (device + ID_SEL_BEGIN)) | (function << 8) | reg;
        type = 0;
    } else {
        /* Type 1 configuration for offboard PCI bus */
        addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
        type = 0x10000;
    }

    /* Clear aborts */
    LOONGSON_PCICMD |= LOONGSON_PCICMD_MABORT_CLR | \
                LOONGSON_PCICMD_MTABORT_CLR;

    LOONGSON_PCIMAP_CFG = (addr >> 16) | type;

    /* Flush Bonito register block */
    dummy = LOONGSON_PCIMAP_CFG;
    mmiowb();

    addrp = CFG_SPACE_REG(addr & 0xffff);
    if (access_type == PCI_ACCESS_WRITE)
        writel(cpu_to_le32(*data), addrp);
    else
        *data = le32_to_cpu(readl(addrp));

    /* Detect Master/Target abort */
    if (LOONGSON_PCICMD & (LOONGSON_PCICMD_MABORT_CLR |
                 LOONGSON_PCICMD_MTABORT_CLR)) {
        /* Error occurred */

        /* Clear bits */
        LOONGSON_PCICMD |= (LOONGSON_PCICMD_MABORT_CLR |
                  LOONGSON_PCICMD_MTABORT_CLR);

        return -1;
    }

    return 0;

}


/*
 * We can't address 8 and 16 bit words directly.  Instead we have to
 * read/write a 32bit word and mask/modify the data we actually want.
 */
static int loongson_pcibios_read(struct pci_bus *bus, unsigned int devfn,
                 int where, int size, u32 *val)
{
    u32 data = 0;

    if ((size == 2) && (where & 1))
        return PCIBIOS_BAD_REGISTER_NUMBER;
    else if ((size == 4) && (where & 3))
        return PCIBIOS_BAD_REGISTER_NUMBER;

    if (loongson_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
                       &data))
        return -1;

    if (size == 1)
        *val = (data >> ((where & 3) << 3)) & 0xff;
    else if (size == 2)
        *val = (data >> ((where & 3) << 3)) & 0xffff;
    else
        *val = data;

    return PCIBIOS_SUCCESSFUL;
}

static int loongson_pcibios_write(struct pci_bus *bus, unsigned int devfn,
                  int where, int size, u32 val)
{
    u32 data = 0;

    if ((size == 2) && (where & 1))
        return PCIBIOS_BAD_REGISTER_NUMBER;
    else if ((size == 4) && (where & 3))
        return PCIBIOS_BAD_REGISTER_NUMBER;

    if (size == 4)
        data = val;
    else {
        if (loongson_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
                    where, &data))
            return -1;

        if (size == 1)
            data = (data & ~(0xff << ((where & 3) << 3))) |
                (val << ((where & 3) << 3));
        else if (size == 2)
            data = (data & ~(0xffff << ((where & 3) << 3))) |
                (val << ((where & 3) << 3));
    }

    if (loongson_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
                       &data))
        return -1;

    return PCIBIOS_SUCCESSFUL;
}

struct pci_ops loongson_pci_ops = {
    .read = loongson_pcibios_read,
    .write = loongson_pcibios_write
};

#ifdef CONFIG_CS5536
DEFINE_RAW_SPINLOCK(msr_lock);

void _rdmsr(u32 msr, u32 *hi, u32 *lo)
{
    struct pci_bus bus = {
        .number = PCI_BUS_CS5536
    };
    u32 devfn = PCI_DEVFN(PCI_IDSEL_CS5536, 0);
    unsigned long flags;

    raw_spin_lock_irqsave(&msr_lock, flags);
    loongson_pcibios_write(&bus, devfn, PCI_MSR_ADDR, 4, msr);
    loongson_pcibios_read(&bus, devfn, PCI_MSR_DATA_LO, 4, lo);
    loongson_pcibios_read(&bus, devfn, PCI_MSR_DATA_HI, 4, hi);
    raw_spin_unlock_irqrestore(&msr_lock, flags);
}
EXPORT_SYMBOL(_rdmsr);

void _wrmsr(u32 msr, u32 hi, u32 lo)
{
    struct pci_bus bus = {
        .number = PCI_BUS_CS5536
    };
    u32 devfn = PCI_DEVFN(PCI_IDSEL_CS5536, 0);
    unsigned long flags;

    raw_spin_lock_irqsave(&msr_lock, flags);
    loongson_pcibios_write(&bus, devfn, PCI_MSR_ADDR, 4, msr);
    loongson_pcibios_write(&bus, devfn, PCI_MSR_DATA_LO, 4, lo);
    loongson_pcibios_write(&bus, devfn, PCI_MSR_DATA_HI, 4, hi);
    raw_spin_unlock_irqrestore(&msr_lock, flags);
}
EXPORT_SYMBOL(_wrmsr);
#endif