ops-bonito64.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]>
 *
 *  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.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * MIPS boards specific PCI support.
 */
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>

#include <asm/mips-boards/bonito64.h>

#define PCI_ACCESS_READ  0
#define PCI_ACCESS_WRITE 1

#define CFG_SPACE_REG(offset) (void *)CKSEG1ADDR(_pcictrl_bonito_pcicfg + (offset))
#define ID_SEL_BEGIN 10
#define MAX_DEV_NUM (31 - ID_SEL_BEGIN)


static int bonito64_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) {
        /* 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 */
    BONITO_PCICMD |= BONITO_PCICMD_MABORT_CLR | BONITO_PCICMD_MTABORT_CLR;

    BONITO_PCIMAP_CFG = (addr >> 16) | type;

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

    addrp = CFG_SPACE_REG(addr & 0xffff);
    if (access_type == PCI_ACCESS_WRITE) {
        writel(cpu_to_le32(*data), addrp);
        /* Wait till done */
        while (BONITO_PCIMSTAT & 0xF);
    } else {
        *data = le32_to_cpu(readl(addrp));
    }

    /* Detect Master/Target abort */
    if (BONITO_PCICMD & (BONITO_PCICMD_MABORT_CLR |
                 BONITO_PCICMD_MTABORT_CLR)) {
        /* Error occurred */

        /* Clear bits */
        BONITO_PCICMD |= (BONITO_PCICMD_MABORT_CLR |
                  BONITO_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 bonito64_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 (bonito64_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 bonito64_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 (bonito64_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 (bonito64_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
                       &data))
        return -1;

    return PCIBIOS_SUCCESSFUL;
}

struct pci_ops bonito64_pci_ops = {
    .read = bonito64_pcibios_read,
    .write = bonito64_pcibios_write
};