Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Routines for tracking a legacy ISA bridge

 *

 * Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.

 *

 * Some bits and pieces moved over from pci_64.c

 *

 * Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp.

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 */

#define DEBUG

#include <linux/kernel.h>

#include <linux/pci.h>

#include <linux/string.h>

#include <linux/init.h>

#include <linux/mm.h>

#include <linux/notifier.h>

#include <asm/processor.h>

#include <asm/io.h>

#include <asm/prom.h>

#include <asm/pci-bridge.h>

#include <asm/machdep.h>

#include <asm/ppc-pci.h>

#include <asm/firmware.h>

unsigned long isa_io_base;      /* NULL if no ISA bus */

EXPORT_SYMBOL(isa_io_base);

/* Cached ISA bridge dev. */

static struct device_node *isa_bridge_devnode;

struct pci_dev *isa_bridge_pcidev;

EXPORT_SYMBOL_GPL(isa_bridge_pcidev);

#define ISA_SPACE_MASK 0x1

#define ISA_SPACE_IO 0x1

static void __devinit pci_process_ISA_OF_ranges(struct device_node *isa_node,

                                                unsigned long phb_io_base_phys)

{

        /* We should get some saner parsing here and remove these structs */

        struct pci_address {

                u32 a_hi;

                u32 a_mid;

                u32 a_lo;

        };

        struct isa_address {

                u32 a_hi;

                u32 a_lo;

        };

        struct isa_range {

                struct isa_address isa_addr;

                struct pci_address pci_addr;

                unsigned int size;

        };

        const struct isa_range *range;

        unsigned long pci_addr;

        unsigned int isa_addr;

        unsigned int size;

        int rlen = 0;

        range = of_get_property(isa_node, "ranges", &rlen);

        if (range == NULL || (rlen < sizeof(struct isa_range)))

                goto inval_range;

        /* From "ISA Binding to 1275"

         * The ranges property is laid out as an array of elements,

         * each of which comprises:

         *   cells 0 - 1:       an ISA address

         *   cells 2 - 4:       a PCI address

         *                      (size depending on dev->n_addr_cells)

         *   cell 5:            the size of the range

         */

        if ((range->isa_addr.a_hi && ISA_SPACE_MASK) != ISA_SPACE_IO) {

                range++;

                rlen -= sizeof(struct isa_range);

                if (rlen < sizeof(struct isa_range))

                        goto inval_range;

        }

        if ((range->isa_addr.a_hi && ISA_SPACE_MASK) != ISA_SPACE_IO)

                goto inval_range;

        isa_addr = range->isa_addr.a_lo;

        pci_addr = (unsigned long) range->pci_addr.a_mid << 32 |

                range->pci_addr.a_lo;

        /* Assume these are both zero. Note: We could fix that and

         * do a proper parsing instead ... oh well, that will do for

         * now as nobody uses fancy mappings for ISA bridges

         */

        if ((pci_addr != 0) || (isa_addr != 0)) {

                printk(KERN_ERR "unexpected isa to pci mapping: %s\n",

                       __FUNCTION__);

                return;

        }

        /* Align size and make sure it's cropped to 64K */

        size = PAGE_ALIGN(range->size);

        if (size > 0x10000)

                size = 0x10000;

        printk(KERN_ERR "no ISA IO ranges or unexpected isa range,"

               "mapping 64k\n");

        __ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,

                     size, _PAGE_NO_CACHE|_PAGE_GUARDED);

        return;

inval_range:

        printk(KERN_ERR "no ISA IO ranges or unexpected isa range,"

               "mapping 64k\n");

        __ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,

                     0x10000, _PAGE_NO_CACHE|_PAGE_GUARDED);

}

/**

 * isa_bridge_find_early - Find and map the ISA IO space early before

 *                         main PCI discovery. This is optionally called by

 *                         the arch code when adding PCI PHBs to get early

 *                         access to ISA IO ports

 */

void __init isa_bridge_find_early(struct pci_controller *hose)

{

        struct device_node *np, *parent = NULL, *tmp;

        /* If we already have an ISA bridge, bail off */

        if (isa_bridge_devnode != NULL)

                return;

        /* For each "isa" node in the system. Note : we do a search by

         * type and not by name. It might be better to do by name but that's

         * what the code used to do and I don't want to break too much at

         * once. We can look into changing that separately

         */

        for_each_node_by_type(np, "isa") {

                /* Look for our hose being a parent */

                for (parent = of_get_parent(np); parent;) {

                        if (parent == hose->arch_data) {

                                of_node_put(parent);

                                break;

                        }

                        tmp = parent;

                        parent = of_get_parent(parent);

                        of_node_put(tmp);

                }

                if (parent != NULL)

                        break;

        }

        if (np == NULL)

                return;

        isa_bridge_devnode = np;

        /* Now parse the "ranges" property and setup the ISA mapping */

        pci_process_ISA_OF_ranges(np, hose->io_base_phys);

        /* Set the global ISA io base to indicate we have an ISA bridge */

        isa_io_base = ISA_IO_BASE;

        pr_debug("ISA bridge (early) is %s\n", np->full_name);

}

/**

 * isa_bridge_find_late - Find and map the ISA IO space upon discovery of

 *                        a new ISA bridge

 */

static void __devinit isa_bridge_find_late(struct pci_dev *pdev,

                                           struct device_node *devnode)

{

        struct pci_controller *hose = pci_bus_to_host(pdev->bus);

        /* Store ISA device node and PCI device */

        isa_bridge_devnode = of_node_get(devnode);

        isa_bridge_pcidev = pdev;

        /* Now parse the "ranges" property and setup the ISA mapping */

        pci_process_ISA_OF_ranges(devnode, hose->io_base_phys);

        /* Set the global ISA io base to indicate we have an ISA bridge */

        isa_io_base = ISA_IO_BASE;

        pr_debug("ISA bridge (late) is %s on %s\n",

                 devnode->full_name, pci_name(pdev));

}

/**

 * isa_bridge_remove - Remove/unmap an ISA bridge

 */

static void isa_bridge_remove(void)

{

        pr_debug("ISA bridge removed !\n");

        /* Clear the global ISA io base to indicate that we have no more

         * ISA bridge. Note that drivers don't quite handle that, though

         * we should probably do something about it. But do we ever really

         * have ISA bridges being removed on machines using legacy devices ?

         */

        isa_io_base = ISA_IO_BASE;

        /* Clear references to the bridge */

        of_node_put(isa_bridge_devnode);

        isa_bridge_devnode = NULL;

        isa_bridge_pcidev = NULL;

        /* Unmap the ISA area */

        __iounmap_at((void *)ISA_IO_BASE, 0x10000);

}

/**

 * isa_bridge_notify - Get notified of PCI devices addition/removal

 */

static int __devinit isa_bridge_notify(struct notifier_block *nb,

                                       unsigned long action, void *data)

{

        struct device *dev = data;

        struct pci_dev *pdev = to_pci_dev(dev);

        struct device_node *devnode = pci_device_to_OF_node(pdev);

        switch(action) {

        case BUS_NOTIFY_ADD_DEVICE:

                /* Check if we have an early ISA device, without PCI dev */

                if (isa_bridge_devnode && isa_bridge_devnode == devnode &&

                    !isa_bridge_pcidev) {

                        pr_debug("ISA bridge PCI attached: %s\n",

                                 pci_name(pdev));

                        isa_bridge_pcidev = pdev;

                }

                /* Check if we have no ISA device, and this happens to be one,

                 * register it as such if it has an OF device

                 */

                if (!isa_bridge_devnode && devnode && devnode->type &&

                    !strcmp(devnode->type, "isa"))

                        isa_bridge_find_late(pdev, devnode);

                return 0;

        case BUS_NOTIFY_DEL_DEVICE:

                /* Check if this our existing ISA device */

                if (pdev == isa_bridge_pcidev ||

                    (devnode && devnode == isa_bridge_devnode))

                        isa_bridge_remove();

                return 0;

        }

        return 0;

}

static struct notifier_block isa_bridge_notifier = {

        .notifier_call = isa_bridge_notify

};

/**

 * isa_bridge_init - register to be notified of ISA bridge addition/removal

 *

 */

static int __init isa_bridge_init(void)

{

        if (firmware_has_feature(FW_FEATURE_ISERIES))

                return 0;

        bus_register_notifier(&pci_bus_type, &isa_bridge_notifier);

        return 0;

}

arch_initcall(isa_bridge_init);