pci.c

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/*
 * arch/arm/plat-iop/pci.c
 *
 * PCI support for the Intel IOP32X and IOP33X processors
 *
 * Author: Rory Bolt <[email protected]>
 * Copyright (C) 2002 Rory Bolt
 *
 * This program is free software; you can redistribute 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/kernel.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <asm/signal.h>
#include <mach/hardware.h>
#include <asm/mach/pci.h>
#include <asm/hardware/iop3xx.h>

// #define DEBUG

#ifdef DEBUG
#define  DBG(x...) printk(x)
#else
#define  DBG(x...) do { } while (0)
#endif

/*
 * This routine builds either a type0 or type1 configuration command.  If the
 * bus is on the 803xx then a type0 made, else a type1 is created.
 */
static u32 iop3xx_cfg_address(struct pci_bus *bus, int devfn, int where)
{
    struct pci_sys_data *sys = bus->sysdata;
    u32 addr;

    if (sys->busnr == bus->number)
        addr = 1 << (PCI_SLOT(devfn) + 16) | (PCI_SLOT(devfn) << 11);
    else
        addr = bus->number << 16 | PCI_SLOT(devfn) << 11 | 1;

    addr |= PCI_FUNC(devfn) << 8 | (where & ~3);

    return addr;
}

/*
 * This routine checks the status of the last configuration cycle.  If an error
 * was detected it returns a 1, else it returns a 0.  The errors being checked
 * are parity, master abort, target abort (master and target).  These types of
 * errors occur during a config cycle where there is no device, like during
 * the discovery stage.
 */
static int iop3xx_pci_status(void)
{
    unsigned int status;
    int ret = 0;

    /*
     * Check the status registers.
     */
    status = *IOP3XX_ATUSR;
    if (status & 0xf900) {
        DBG("\t\t\tPCI: P0 - status = 0x%08x\n", status);
        *IOP3XX_ATUSR = status & 0xf900;
        ret = 1;
    }

    status = *IOP3XX_ATUISR;
    if (status & 0x679f) {
        DBG("\t\t\tPCI: P1 - status = 0x%08x\n", status);
        *IOP3XX_ATUISR = status & 0x679f;
        ret = 1;
    }

    return ret;
}

/*
 * Simply write the address register and read the configuration
 * data.  Note that the 4 nops ensure that we are able to handle
 * a delayed abort (in theory.)
 */
static u32 iop3xx_read(unsigned long addr)
{
    u32 val;

    __asm__ __volatile__(
        "str    %1, [%2]\n\t"
        "ldr    %0, [%3]\n\t"
        "nop\n\t"
        "nop\n\t"
        "nop\n\t"
        "nop\n\t"
        : "=r" (val)
        : "r" (addr), "r" (IOP3XX_OCCAR), "r" (IOP3XX_OCCDR));

    return val;
}

/*
 * The read routines must check the error status of the last configuration
 * cycle.  If there was an error, the routine returns all hex f's.
 */
static int
iop3xx_read_config(struct pci_bus *bus, unsigned int devfn, int where,
        int size, u32 *value)
{
    unsigned long addr = iop3xx_cfg_address(bus, devfn, where);
    u32 val = iop3xx_read(addr) >> ((where & 3) * 8);

    if (iop3xx_pci_status())
        val = 0xffffffff;

    *value = val;

    return PCIBIOS_SUCCESSFUL;
}

static int
iop3xx_write_config(struct pci_bus *bus, unsigned int devfn, int where,
        int size, u32 value)
{
    unsigned long addr = iop3xx_cfg_address(bus, devfn, where);
    u32 val;

    if (size != 4) {
        val = iop3xx_read(addr);
        if (iop3xx_pci_status())
            return PCIBIOS_SUCCESSFUL;

        where = (where & 3) * 8;

        if (size == 1)
            val &= ~(0xff << where);
        else
            val &= ~(0xffff << where);

        *IOP3XX_OCCDR = val | value << where;
    } else {
        asm volatile(
            "str    %1, [%2]\n\t"
            "str    %0, [%3]\n\t"
            "nop\n\t"
            "nop\n\t"
            "nop\n\t"
            "nop\n\t"
            :
            : "r" (value), "r" (addr),
              "r" (IOP3XX_OCCAR), "r" (IOP3XX_OCCDR));
    }

    return PCIBIOS_SUCCESSFUL;
}

struct pci_ops iop3xx_ops = {
    .read   = iop3xx_read_config,
    .write  = iop3xx_write_config,
};

/*
 * When a PCI device does not exist during config cycles, the 80200 gets a
 * bus error instead of returning 0xffffffff. This handler simply returns.
 */
static int
iop3xx_pci_abort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
    DBG("PCI abort: address = 0x%08lx fsr = 0x%03x PC = 0x%08lx LR = 0x%08lx\n",
        addr, fsr, regs->ARM_pc, regs->ARM_lr);

    /*
     * If it was an imprecise abort, then we need to correct the
     * return address to be _after_ the instruction.
     */
    if (fsr & (1 << 10))
        regs->ARM_pc += 4;

    return 0;
}

int iop3xx_pci_setup(int nr, struct pci_sys_data *sys)
{
    struct resource *res;

    if (nr != 0)
        return 0;

    res = kzalloc(sizeof(struct resource), GFP_KERNEL);
    if (!res)
        panic("PCI: unable to alloc resources");

    res->start = IOP3XX_PCI_LOWER_MEM_PA;
    res->end   = IOP3XX_PCI_LOWER_MEM_PA + IOP3XX_PCI_MEM_WINDOW_SIZE - 1;
    res->name  = "IOP3XX PCI Memory Space";
    res->flags = IORESOURCE_MEM;
    request_resource(&iomem_resource, res);

    /*
     * Use whatever translation is already setup.
     */
    sys->mem_offset = IOP3XX_PCI_LOWER_MEM_PA - *IOP3XX_OMWTVR0;

    pci_add_resource_offset(&sys->resources, res, sys->mem_offset);

    pci_ioremap_io(0, IOP3XX_PCI_LOWER_IO_PA);

    return 1;
}

void __init iop3xx_atu_setup(void)
{
    /* BAR 0 ( Disabled ) */
    *IOP3XX_IAUBAR0 = 0x0;
    *IOP3XX_IABAR0  = 0x0;
    *IOP3XX_IATVR0  = 0x0;
    *IOP3XX_IALR0   = 0x0;

    /* BAR 1 ( Disabled ) */
    *IOP3XX_IAUBAR1 = 0x0;
    *IOP3XX_IABAR1  = 0x0;
    *IOP3XX_IALR1   = 0x0;

    /* BAR 2 (1:1 mapping with Physical RAM) */
    /* Set limit and enable */
    *IOP3XX_IALR2 = ~((u32)IOP3XX_MAX_RAM_SIZE - 1) & ~0x1;
    *IOP3XX_IAUBAR2 = 0x0;

    /* Align the inbound bar with the base of memory */
    *IOP3XX_IABAR2 = PHYS_OFFSET |
                   PCI_BASE_ADDRESS_MEM_TYPE_64 |
                   PCI_BASE_ADDRESS_MEM_PREFETCH;

    *IOP3XX_IATVR2 = PHYS_OFFSET;

    /* Outbound window 0 */
    *IOP3XX_OMWTVR0 = IOP3XX_PCI_LOWER_MEM_BA;
    *IOP3XX_OUMWTVR0 = 0;

    /* Outbound window 1 */
    *IOP3XX_OMWTVR1 = IOP3XX_PCI_LOWER_MEM_BA +
              IOP3XX_PCI_MEM_WINDOW_SIZE / 2;
    *IOP3XX_OUMWTVR1 = 0;

    /* BAR 3 ( Disabled ) */
    *IOP3XX_IAUBAR3 = 0x0;
    *IOP3XX_IABAR3  = 0x0;
    *IOP3XX_IATVR3  = 0x0;
    *IOP3XX_IALR3   = 0x0;

    /* Setup the I/O Bar
     */
    *IOP3XX_OIOWTVR = IOP3XX_PCI_LOWER_IO_BA;

    /* Enable inbound and outbound cycles
     */
    *IOP3XX_ATUCMD |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
                   PCI_COMMAND_PARITY | PCI_COMMAND_SERR;
    *IOP3XX_ATUCR |= IOP3XX_ATUCR_OUT_EN;
}

void __init iop3xx_atu_disable(void)
{
    *IOP3XX_ATUCMD = 0;
    *IOP3XX_ATUCR = 0;

    /* wait for cycles to quiesce */
    while (*IOP3XX_PCSR & (IOP3XX_PCSR_OUT_Q_BUSY |
                     IOP3XX_PCSR_IN_Q_BUSY))
        cpu_relax();

    /* BAR 0 ( Disabled ) */
    *IOP3XX_IAUBAR0 = 0x0;
    *IOP3XX_IABAR0  = 0x0;
    *IOP3XX_IATVR0  = 0x0;
    *IOP3XX_IALR0   = 0x0;

    /* BAR 1 ( Disabled ) */
    *IOP3XX_IAUBAR1 = 0x0;
    *IOP3XX_IABAR1  = 0x0;
    *IOP3XX_IALR1   = 0x0;

    /* BAR 2 ( Disabled ) */
    *IOP3XX_IAUBAR2 = 0x0;
    *IOP3XX_IABAR2  = 0x0;
    *IOP3XX_IATVR2  = 0x0;
    *IOP3XX_IALR2   = 0x0;

    /* BAR 3 ( Disabled ) */
    *IOP3XX_IAUBAR3 = 0x0;
    *IOP3XX_IABAR3  = 0x0;
    *IOP3XX_IATVR3  = 0x0;
    *IOP3XX_IALR3   = 0x0;

    /* Clear the outbound windows */
    *IOP3XX_OIOWTVR  = 0;

    /* Outbound window 0 */
    *IOP3XX_OMWTVR0 = 0;
    *IOP3XX_OUMWTVR0 = 0;

    /* Outbound window 1 */
    *IOP3XX_OMWTVR1 = 0;
    *IOP3XX_OUMWTVR1 = 0;
}

/* Flag to determine whether the ATU is initialized and the PCI bus scanned */
int init_atu;

int iop3xx_get_init_atu(void) {
    /* check if default has been overridden */
    if (init_atu != IOP3XX_INIT_ATU_DEFAULT)
        return init_atu;
    else
        return IOP3XX_INIT_ATU_DISABLE;
}

static void __init iop3xx_atu_debug(void)
{
    DBG("PCI: Intel IOP3xx PCI init.\n");
    DBG("PCI: Outbound memory window 0: PCI 0x%08x%08x\n",
        *IOP3XX_OUMWTVR0, *IOP3XX_OMWTVR0);
    DBG("PCI: Outbound memory window 1: PCI 0x%08x%08x\n",
        *IOP3XX_OUMWTVR1, *IOP3XX_OMWTVR1);
    DBG("PCI: Outbound IO window: PCI 0x%08x\n",
        *IOP3XX_OIOWTVR);

    DBG("PCI: Inbound memory window 0: PCI 0x%08x%08x 0x%08x -> 0x%08x\n",
        *IOP3XX_IAUBAR0, *IOP3XX_IABAR0, *IOP3XX_IALR0, *IOP3XX_IATVR0);
    DBG("PCI: Inbound memory window 1: PCI 0x%08x%08x 0x%08x\n",
        *IOP3XX_IAUBAR1, *IOP3XX_IABAR1, *IOP3XX_IALR1);
    DBG("PCI: Inbound memory window 2: PCI 0x%08x%08x 0x%08x -> 0x%08x\n",
        *IOP3XX_IAUBAR2, *IOP3XX_IABAR2, *IOP3XX_IALR2, *IOP3XX_IATVR2);
    DBG("PCI: Inbound memory window 3: PCI 0x%08x%08x 0x%08x -> 0x%08x\n",
        *IOP3XX_IAUBAR3, *IOP3XX_IABAR3, *IOP3XX_IALR3, *IOP3XX_IATVR3);

    DBG("PCI: Expansion ROM window: PCI 0x%08x%08x 0x%08x -> 0x%08x\n",
        0, *IOP3XX_ERBAR, *IOP3XX_ERLR, *IOP3XX_ERTVR);

    DBG("ATU: IOP3XX_ATUCMD=0x%04x\n", *IOP3XX_ATUCMD);
    DBG("ATU: IOP3XX_ATUCR=0x%08x\n", *IOP3XX_ATUCR);

    hook_fault_code(16+6, iop3xx_pci_abort, SIGBUS, 0, "imprecise external abort");
}

/* for platforms that might be host-bus-adapters */
void __init iop3xx_pci_preinit_cond(void)
{
    if (iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE) {
        iop3xx_atu_disable();
        iop3xx_atu_setup();
        iop3xx_atu_debug();
    }
}

void __init iop3xx_pci_preinit(void)
{
    pcibios_min_mem = 0;

    iop3xx_atu_disable();
    iop3xx_atu_setup();
    iop3xx_atu_debug();
}

/* allow init_atu to be user overridden */
static int __init iop3xx_init_atu_setup(char *str)
{
    init_atu = IOP3XX_INIT_ATU_DEFAULT;
    if (str) {
        while (*str != '\0') {
            switch (*str) {
            case 'y':
            case 'Y':
                init_atu = IOP3XX_INIT_ATU_ENABLE;
                break;
            case 'n':
            case 'N':
                init_atu = IOP3XX_INIT_ATU_DISABLE;
                break;
            case ',':
            case '=':
                break;
            default:
                printk(KERN_DEBUG "\"%s\" malformed at "
                        "character: \'%c\'",
                        __func__,
                        *str);
                *(str + 1) = '\0';
            }
            str++;
        }
    }

    return 1;
}

__setup("iop3xx_init_atu", iop3xx_init_atu_setup);