/*
 * Compaq Hot Plug Controller Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (C) 2001 IBM Corp.
 *
 * All rights reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <greg@kroah.com>
 *
 * Jan 12, 2003 -       Added 66/100/133MHz PCI-X support,
 *                      Torben Mathiasen <torben.mathiasen@hp.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/init.h>
#include <linux/interrupt.h>

#include <asm/uaccess.h>

#include "cpqphp.h"
#include "cpqphp_nvram.h"


/* Global variables */
int cpqhp_debug;
int cpqhp_legacy_mode;
struct controller *cpqhp_ctrl_list;     /* = NULL */
struct pci_func *cpqhp_slot_list[256];
struct irq_routing_table *cpqhp_routing_table;

/* local variables */
static void __iomem *smbios_table;
static void __iomem *smbios_start;
static void __iomem *cpqhp_rom_start;
static int power_mode;
static int debug;
static int initialized;

#define DRIVER_VERSION  "0.9.8"
#define DRIVER_AUTHOR   "Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>"
#define DRIVER_DESC     "Compaq Hot Plug PCI Controller Driver"

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

module_param(power_mode, bool, 0644);
MODULE_PARM_DESC(power_mode, "Power mode enabled or not");

module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");

#define CPQHPC_MODULE_MINOR 208

static inline int is_slot64bit(struct slot *slot)
{
        return (readb(slot->p_sm_slot + SMBIOS_SLOT_WIDTH) == 0x06) ? 1 : 0;
}

static inline int is_slot66mhz(struct slot *slot)
{
        return (readb(slot->p_sm_slot + SMBIOS_SLOT_TYPE) == 0x0E) ? 1 : 0;
}

/**
 * detect_SMBIOS_pointer - find the System Management BIOS Table in mem region.
 * @begin: begin pointer for region to be scanned.
 * @end: end pointer for region to be scanned.
 *
 * Returns pointer to the head of the SMBIOS tables (or %NULL).
 */
static void __iomem * detect_SMBIOS_pointer(void __iomem *begin, void __iomem *end)
{
        void __iomem *fp;
        void __iomem *endp;
        u8 temp1, temp2, temp3, temp4;
        int status = 0;

        endp = (end - sizeof(u32) + 1);

        for (fp = begin; fp <= endp; fp += 16) {
                temp1 = readb(fp);
                temp2 = readb(fp+1);
                temp3 = readb(fp+2);
                temp4 = readb(fp+3);
                if (temp1 == '_' &&
                    temp2 == 'S' &&
                    temp3 == 'M' &&
                    temp4 == '_') {
                        status = 1;
                        break;
                }
        }

        if (!status)
                fp = NULL;

        dbg("Discovered SMBIOS Entry point at %p\n", fp);

        return fp;
}

/**
 * init_SERR - Initializes the per slot SERR generation.
 * @ctrl: controller to use
 *
 * For unexpected switch opens
 */
static int init_SERR(struct controller * ctrl)
{
        u32 tempdword;
        u32 number_of_slots;
        u8 physical_slot;

        if (!ctrl)
                return 1;

        tempdword = ctrl->first_slot;

        number_of_slots = readb(ctrl->hpc_reg + SLOT_MASK) & 0x0F;
        /* Loop through slots */
        while (number_of_slots) {
                physical_slot = tempdword;
                writeb(0, ctrl->hpc_reg + SLOT_SERR);
                tempdword++;
                number_of_slots--;
        }

        return 0;
}

static int init_cpqhp_routing_table(void)
{
        int len;

        cpqhp_routing_table = pcibios_get_irq_routing_table();
        if (cpqhp_routing_table == NULL)
                return -ENOMEM;

        len = cpqhp_routing_table_length();
        if (len == 0) {
                kfree(cpqhp_routing_table);
                cpqhp_routing_table = NULL;
                return -1;
        }

        return 0;
}

/* nice debugging output */
static void pci_print_IRQ_route(void)
{
        int len;
        int loop;
        u8 tbus, tdevice, tslot;

        len = cpqhp_routing_table_length();

        dbg("bus dev func slot\n");
        for (loop = 0; loop < len; ++loop) {
                tbus = cpqhp_routing_table->slots[loop].bus;
                tdevice = cpqhp_routing_table->slots[loop].devfn;
                tslot = cpqhp_routing_table->slots[loop].slot;
                dbg("%d %d %d %d\n", tbus, tdevice >> 3, tdevice & 0x7, tslot);

        }
        return;
}


/**
 * get_subsequent_smbios_entry: get the next entry from bios table.
 * @smbios_start: where to start in the SMBIOS table
 * @smbios_table: location of the SMBIOS table
 * @curr: %NULL or pointer to previously returned structure
 *
 * Gets the first entry if previous == NULL;
 * otherwise, returns the next entry.
 * Uses global SMBIOS Table pointer.
 *
 * Returns a pointer to an SMBIOS structure or NULL if none found.
 */
static void __iomem *get_subsequent_smbios_entry(void __iomem *smbios_start,
                                                void __iomem *smbios_table,
                                                void __iomem *curr)
{
        u8 bail = 0;
        u8 previous_byte = 1;
        void __iomem *p_temp;
        void __iomem *p_max;

        if (!smbios_table || !curr)
                return NULL;

        /* set p_max to the end of the table */
        p_max = smbios_start + readw(smbios_table + ST_LENGTH);

        p_temp = curr;
        p_temp += readb(curr + SMBIOS_GENERIC_LENGTH);

        while ((p_temp < p_max) && !bail) {
                /* Look for the double NULL terminator
                 * The first condition is the previous byte
                 * and the second is the curr
                 */
                if (!previous_byte && !(readb(p_temp)))
                        bail = 1;

                previous_byte = readb(p_temp);
                p_temp++;
        }

        if (p_temp < p_max)
                return p_temp;
        else
                return NULL;
}


/**
 * get_SMBIOS_entry - return the requested SMBIOS entry or %NULL
 * @smbios_start: where to start in the SMBIOS table
 * @smbios_table: location of the SMBIOS table
 * @type: SMBIOS structure type to be returned
 * @previous: %NULL or pointer to previously returned structure
 *
 * Gets the first entry of the specified type if previous == %NULL;
 * Otherwise, returns the next entry of the given type.
 * Uses global SMBIOS Table pointer.
 * Uses get_subsequent_smbios_entry.
 *
 * Returns a pointer to an SMBIOS structure or %NULL if none found.
 */
static void __iomem *get_SMBIOS_entry(void __iomem *smbios_start,
                                        void __iomem *smbios_table,
                                        u8 type,
                                        void __iomem *previous)
{
        if (!smbios_table)
                return NULL;

        if (!previous)
                previous = smbios_start;
        else
                previous = get_subsequent_smbios_entry(smbios_start,
                                        smbios_table, previous);

        while (previous)
                if (readb(previous + SMBIOS_GENERIC_TYPE) != type)
                        previous = get_subsequent_smbios_entry(smbios_start,
                                                smbios_table, previous);
                else
                        break;

        return previous;
}

static void release_slot(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot = hotplug_slot->private;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        kfree(slot->hotplug_slot->info);
        kfree(slot->hotplug_slot);
        kfree(slot);
}

static int ctrl_slot_cleanup (struct controller * ctrl)
{
        struct slot *old_slot, *next_slot;

        old_slot = ctrl->slot;
        ctrl->slot = NULL;

        while (old_slot) {
                /* memory will be freed by the release_slot callback */
                next_slot = old_slot->next;
                pci_hp_deregister (old_slot->hotplug_slot);
                old_slot = next_slot;
        }

        cpqhp_remove_debugfs_files(ctrl);

        /* Free IRQ associated with hot plug device */
        free_irq(ctrl->interrupt, ctrl);
        /* Unmap the memory */
        iounmap(ctrl->hpc_reg);
        /* Finally reclaim PCI mem */
        release_mem_region(pci_resource_start(ctrl->pci_dev, 0),
                           pci_resource_len(ctrl->pci_dev, 0));

        return 0;
}


/**
 * get_slot_mapping - determine logical slot mapping for PCI device
 *
 * Won't work for more than one PCI-PCI bridge in a slot.
 *
 * @bus_num - bus number of PCI device
 * @dev_num - device number of PCI device
 * @slot - Pointer to u8 where slot number will be returned
 *
 * Output:      SUCCESS or FAILURE
 */
static int
get_slot_mapping(struct pci_bus *bus, u8 bus_num, u8 dev_num, u8 *slot)
{
        u32 work;
        long len;
        long loop;

        u8 tbus, tdevice, tslot, bridgeSlot;

        dbg("%s: %p, %d, %d, %p\n", __func__, bus, bus_num, dev_num, slot);

        bridgeSlot = 0xFF;

        len = cpqhp_routing_table_length();
        for (loop = 0; loop < len; ++loop) {
                tbus = cpqhp_routing_table->slots[loop].bus;
                tdevice = cpqhp_routing_table->slots[loop].devfn >> 3;
                tslot = cpqhp_routing_table->slots[loop].slot;

                if ((tbus == bus_num) && (tdevice == dev_num)) {
                        *slot = tslot;
                        return 0;
                } else {
                        /* Did not get a match on the target PCI device. Check
                         * if the current IRQ table entry is a PCI-to-PCI
                         * bridge device.  If so, and it's secondary bus
                         * matches the bus number for the target device, I need
                         * to save the bridge's slot number.  If I can not find
                         * an entry for the target device, I will have to
                         * assume it's on the other side of the bridge, and
                         * assign it the bridge's slot.
                         */
                        bus->number = tbus;
                        pci_bus_read_config_dword(bus, PCI_DEVFN(tdevice, 0),
                                                PCI_CLASS_REVISION, &work);

                        if ((work >> 8) == PCI_TO_PCI_BRIDGE_CLASS) {
                                pci_bus_read_config_dword(bus,
                                                        PCI_DEVFN(tdevice, 0),
                                                        PCI_PRIMARY_BUS, &work);
                                // See if bridge's secondary bus matches target bus.
                                if (((work >> 8) & 0x000000FF) == (long) bus_num)
                                        bridgeSlot = tslot;
                        }
                }

        }

        /* If we got here, we didn't find an entry in the IRQ mapping table for
         * the target PCI device.  If we did determine that the target device
         * is on the other side of a PCI-to-PCI bridge, return the slot number
         * for the bridge.
         */
        if (bridgeSlot != 0xFF) {
                *slot = bridgeSlot;
                return 0;
        }
        /* Couldn't find an entry in the routing table for this PCI device */
        return -1;
}


/**
 * cpqhp_set_attention_status - Turns the Amber LED for a slot on or off
 * @ctrl: struct controller to use
 * @func: PCI device/function info
 * @status: LED control flag: 1 = LED on, 0 = LED off
 */
static int
cpqhp_set_attention_status(struct controller *ctrl, struct pci_func *func,
                                u32 status)
{
        u8 hp_slot;

        if (func == NULL)
                return 1;

        hp_slot = func->device - ctrl->slot_device_offset;

        /* Wait for exclusive access to hardware */
        mutex_lock(&ctrl->crit_sect);

        if (status == 1)
                amber_LED_on (ctrl, hp_slot);
        else if (status == 0)
                amber_LED_off (ctrl, hp_slot);
        else {
                /* Done with exclusive hardware access */
                mutex_unlock(&ctrl->crit_sect);
                return 1;
        }

        set_SOGO(ctrl);

        /* Wait for SOBS to be unset */
        wait_for_ctrl_irq (ctrl);

        /* Done with exclusive hardware access */
        mutex_unlock(&ctrl->crit_sect);

        return 0;
}


/**
 * set_attention_status - Turns the Amber LED for a slot on or off
 * @hotplug_slot: slot to change LED on
 * @status: LED control flag
 */
static int set_attention_status (struct hotplug_slot *hotplug_slot, u8 status)
{
        struct pci_func *slot_func;
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;
        u8 bus;
        u8 devfn;
        u8 device;
        u8 function;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        if (cpqhp_get_bus_dev(ctrl, &bus, &devfn, slot->number) == -1)
                return -ENODEV;

        device = devfn >> 3;
        function = devfn & 0x7;
        dbg("bus, dev, fn = %d, %d, %d\n", bus, device, function);

        slot_func = cpqhp_slot_find(bus, device, function);
        if (!slot_func)
                return -ENODEV;

        return cpqhp_set_attention_status(ctrl, slot_func, status);
}


static int process_SI(struct hotplug_slot *hotplug_slot)
{
        struct pci_func *slot_func;
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;
        u8 bus;
        u8 devfn;
        u8 device;
        u8 function;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        if (cpqhp_get_bus_dev(ctrl, &bus, &devfn, slot->number) == -1)
                return -ENODEV;

        device = devfn >> 3;
        function = devfn & 0x7;
        dbg("bus, dev, fn = %d, %d, %d\n", bus, device, function);

        slot_func = cpqhp_slot_find(bus, device, function);
        if (!slot_func)
                return -ENODEV;

        slot_func->bus = bus;
        slot_func->device = device;
        slot_func->function = function;
        slot_func->configured = 0;
        dbg("board_added(%p, %p)\n", slot_func, ctrl);
        return cpqhp_process_SI(ctrl, slot_func);
}


static int process_SS(struct hotplug_slot *hotplug_slot)
{
        struct pci_func *slot_func;
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;
        u8 bus;
        u8 devfn;
        u8 device;
        u8 function;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        if (cpqhp_get_bus_dev(ctrl, &bus, &devfn, slot->number) == -1)
                return -ENODEV;

        device = devfn >> 3;
        function = devfn & 0x7;
        dbg("bus, dev, fn = %d, %d, %d\n", bus, device, function);

        slot_func = cpqhp_slot_find(bus, device, function);
        if (!slot_func)
                return -ENODEV;

        dbg("In %s, slot_func = %p, ctrl = %p\n", __func__, slot_func, ctrl);
        return cpqhp_process_SS(ctrl, slot_func);
}


static int hardware_test(struct hotplug_slot *hotplug_slot, u32 value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        return cpqhp_hardware_test(ctrl, value);
}


static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        *value = get_slot_enabled(ctrl, slot);
        return 0;
}

static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        *value = cpq_get_attention_status(ctrl, slot);
        return 0;
}

static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        *value = cpq_get_latch_status(ctrl, slot);

        return 0;
}

static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        *value = get_presence_status(ctrl, slot);

        return 0;
}

static int get_max_bus_speed (struct hotplug_slot *hotplug_slot, enum pci_bus_speed *value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        *value = ctrl->speed_capability;

        return 0;
}

static int get_cur_bus_speed (struct hotplug_slot *hotplug_slot, enum pci_bus_speed *value)
{
        struct slot *slot = hotplug_slot->private;
        struct controller *ctrl = slot->ctrl;

        dbg("%s - physical_slot = %s\n", __func__, slot_name(slot));

        *value = ctrl->speed;

        return 0;
}

static struct hotplug_slot_ops cpqphp_hotplug_slot_ops = {
        .set_attention_status = set_attention_status,
        .enable_slot =          process_SI,
        .disable_slot =         process_SS,
        .hardware_test =        hardware_test,
        .get_power_status =     get_power_status,
        .get_attention_status = get_attention_status,
        .get_latch_status =     get_latch_status,
        .get_adapter_status =   get_adapter_status,
        .get_max_bus_speed =    get_max_bus_speed,
        .get_cur_bus_speed =    get_cur_bus_speed,
};

#define SLOT_NAME_SIZE 10

static int ctrl_slot_setup(struct controller *ctrl,
                        void __iomem *smbios_start,
                        void __iomem *smbios_table)
{
        struct slot *slot;
        struct hotplug_slot *hotplug_slot;
        struct hotplug_slot_info *hotplug_slot_info;
        u8 number_of_slots;
        u8 slot_device;
        u8 slot_number;
        u8 ctrl_slot;
        u32 tempdword;
        char name[SLOT_NAME_SIZE];
        void __iomem *slot_entry= NULL;
        int result = -ENOMEM;

        dbg("%s\n", __func__);

        tempdword = readl(ctrl->hpc_reg + INT_INPUT_CLEAR);

        number_of_slots = readb(ctrl->hpc_reg + SLOT_MASK) & 0x0F;
        slot_device = readb(ctrl->hpc_reg + SLOT_MASK) >> 4;
        slot_number = ctrl->first_slot;

        while (number_of_slots) {
                slot = kzalloc(sizeof(*slot), GFP_KERNEL);
                if (!slot)
                        goto error;

                slot->hotplug_slot = kzalloc(sizeof(*(slot->hotplug_slot)),
                                                GFP_KERNEL);
                if (!slot->hotplug_slot)
                        goto error_slot;
                hotplug_slot = slot->hotplug_slot;

                hotplug_slot->info = kzalloc(sizeof(*(hotplug_slot->info)),
                                                        GFP_KERNEL);
                if (!hotplug_slot->info)
                        goto error_hpslot;
                hotplug_slot_info = hotplug_slot->info;

                slot->ctrl = ctrl;
                slot->bus = ctrl->bus;
                slot->device = slot_device;
                slot->number = slot_number;
                dbg("slot->number = %u\n", slot->number);

                slot_entry = get_SMBIOS_entry(smbios_start, smbios_table, 9,
                                        slot_entry);

                while (slot_entry && (readw(slot_entry + SMBIOS_SLOT_NUMBER) !=
                                slot->number)) {
                        slot_entry = get_SMBIOS_entry(smbios_start,
                                                smbios_table, 9, slot_entry);
                }

                slot->p_sm_slot = slot_entry;

                init_timer(&slot->task_event);
                slot->task_event.expires = jiffies + 5 * HZ;
                slot->task_event.function = cpqhp_pushbutton_thread;

                /*FIXME: these capabilities aren't used but if they are
                 *       they need to be correctly implemented
                 */
                slot->capabilities |= PCISLOT_REPLACE_SUPPORTED;
                slot->capabilities |= PCISLOT_INTERLOCK_SUPPORTED;

                if (is_slot64bit(slot))
                        slot->capabilities |= PCISLOT_64_BIT_SUPPORTED;
                if (is_slot66mhz(slot))
                        slot->capabilities |= PCISLOT_66_MHZ_SUPPORTED;
                if (ctrl->speed == PCI_SPEED_66MHz)
                        slot->capabilities |= PCISLOT_66_MHZ_OPERATION;

                ctrl_slot =
                        slot_device - (readb(ctrl->hpc_reg + SLOT_MASK) >> 4);

                /* Check presence */
                slot->capabilities |=
                        ((((~tempdword) >> 23) |
                         ((~tempdword) >> 15)) >> ctrl_slot) & 0x02;
                /* Check the switch state */
                slot->capabilities |=
                        ((~tempdword & 0xFF) >> ctrl_slot) & 0x01;
                /* Check the slot enable */
                slot->capabilities |=
                        ((read_slot_enable(ctrl) << 2) >> ctrl_slot) & 0x04;

                /* register this slot with the hotplug pci core */
                hotplug_slot->release = &release_slot;
                hotplug_slot->private = slot;
                snprintf(name, SLOT_NAME_SIZE, "%u", slot->number);
                hotplug_slot->ops = &cpqphp_hotplug_slot_ops;

                hotplug_slot_info->power_status = get_slot_enabled(ctrl, slot);
                hotplug_slot_info->attention_status =
                        cpq_get_attention_status(ctrl, slot);
                hotplug_slot_info->latch_status =
                        cpq_get_latch_status(ctrl, slot);
                hotplug_slot_info->adapter_status =
                        get_presence_status(ctrl, slot);

                dbg("registering bus %d, dev %d, number %d, "
                                "ctrl->slot_device_offset %d, slot %d\n",
                                slot->bus, slot->device,
                                slot->number, ctrl->slot_device_offset,
                                slot_number);
                result = pci_hp_register(hotplug_slot,
                                         ctrl->pci_dev->bus,
                                         slot->device,
                                         name);
                if (result) {
                        err("pci_hp_register failed with error %d\n", result);
                        goto error_info;
                }

                slot->next = ctrl->slot;
                ctrl->slot = slot;

                number_of_slots--;
                slot_device++;
                slot_number++;
        }

        return 0;
error_info:
        kfree(hotplug_slot_info);
error_hpslot:
        kfree(hotplug_slot);
error_slot:
        kfree(slot);
error:
        return result;
}

static int one_time_init(void)
{
        int loop;
        int retval = 0;

        if (initialized)
                return 0;

        power_mode = 0;

        retval = init_cpqhp_routing_table();
        if (retval)
                goto error;

        if (cpqhp_debug)
                pci_print_IRQ_route();

        dbg("Initialize + Start the notification mechanism \n");

        retval = cpqhp_event_start_thread();
        if (retval)
                goto error;

        dbg("Initialize slot lists\n");
        for (loop = 0; loop < 256; loop++)
                cpqhp_slot_list[loop] = NULL;

        /* FIXME: We also need to hook the NMI handler eventually.
         * this also needs to be worked with Christoph
         * register_NMI_handler();
         */
        /* Map rom address */
        cpqhp_rom_start = ioremap(ROM_PHY_ADDR, ROM_PHY_LEN);
        if (!cpqhp_rom_start) {
                err ("Could not ioremap memory region for ROM\n");
                retval = -EIO;
                goto error;
        }

        /* Now, map the int15 entry point if we are on compaq specific
         * hardware
         */
        compaq_nvram_init(cpqhp_rom_start);

        /* Map smbios table entry point structure */
        smbios_table = detect_SMBIOS_pointer(cpqhp_rom_start,
                                        cpqhp_rom_start + ROM_PHY_LEN);
        if (!smbios_table) {
                err ("Could not find the SMBIOS pointer in memory\n");
                retval = -EIO;
                goto error_rom_start;
        }

        smbios_start = ioremap(readl(smbios_table + ST_ADDRESS),
                                        readw(smbios_table + ST_LENGTH));
        if (!smbios_start) {
                err ("Could not ioremap memory region taken from SMBIOS values\n");
                retval = -EIO;
                goto error_smbios_start;
        }

        initialized = 1;

        return retval;

error_smbios_start:
        iounmap(smbios_start);
error_rom_start:
        iounmap(cpqhp_rom_start);
error:
        return retval;
}

static int cpqhpc_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        u8 num_of_slots = 0;
        u8 hp_slot = 0;
        u8 device;
        u8 bus_cap;
        u16 temp_word;
        u16 vendor_id;
        u16 subsystem_vid;
        u16 subsystem_deviceid;
        u32 rc;
        struct controller *ctrl;
        struct pci_func *func;
        int err;

        err = pci_enable_device(pdev);
        if (err) {
                printk(KERN_ERR MY_NAME ": cannot enable PCI device %s (%d)\n",
                        pci_name(pdev), err);
                return err;
        }

        /* Need to read VID early b/c it's used to differentiate CPQ and INTC
         * discovery
         */
        rc = pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor_id);
        if (rc || ((vendor_id != PCI_VENDOR_ID_COMPAQ) && (vendor_id != PCI_VENDOR_ID_INTEL))) {
                err(msg_HPC_non_compaq_or_intel);
                rc = -ENODEV;
                goto err_disable_device;
        }
        dbg("Vendor ID: %x\n", vendor_id);

        dbg("revision: %d\n", pdev->revision);
        if ((vendor_id == PCI_VENDOR_ID_COMPAQ) && (!pdev->revision)) {
                err(msg_HPC_rev_error);
                rc = -ENODEV;
                goto err_disable_device;
        }

        /* Check for the proper subsytem ID's
         * Intel uses a different SSID programming model than Compaq.
         * For Intel, each SSID bit identifies a PHP capability.
         * Also Intel HPC's may have RID=0.
         */
        if ((pdev->revision <= 2) && (vendor_id != PCI_VENDOR_ID_INTEL)) {
                err(msg_HPC_not_supported);
                return -ENODEV;
        }

        /* TODO: This code can be made to support non-Compaq or Intel
         * subsystem IDs
         */
        rc = pci_read_config_word(pdev, PCI_SUBSYSTEM_VENDOR_ID, &subsystem_vid);
        if (rc) {
                err("%s : pci_read_config_word failed\n", __func__);
                goto err_disable_device;
        }
        dbg("Subsystem Vendor ID: %x\n", subsystem_vid);
        if ((subsystem_vid != PCI_VENDOR_ID_COMPAQ) && (subsystem_vid != PCI_VENDOR_ID_INTEL)) {
                err(msg_HPC_non_compaq_or_intel);
                rc = -ENODEV;
                goto err_disable_device;
        }

        ctrl = kzalloc(sizeof(struct controller), GFP_KERNEL);
        if (!ctrl) {
                err("%s : out of memory\n", __func__);
                rc = -ENOMEM;
                goto err_disable_device;
        }

        rc = pci_read_config_word(pdev, PCI_SUBSYSTEM_ID, &subsystem_deviceid);
        if (rc) {
                err("%s : pci_read_config_word failed\n", __func__);
                goto err_free_ctrl;
        }

        info("Hot Plug Subsystem Device ID: %x\n", subsystem_deviceid);

        /* Set Vendor ID, so it can be accessed later from other
         * functions
         */
        ctrl->vendor_id = vendor_id;

        switch (subsystem_vid) {
        case PCI_VENDOR_ID_COMPAQ:
                if (pdev->revision >= 0x13) { /* CIOBX */
                        ctrl->push_flag = 1;
                        ctrl->slot_switch_type = 1;
                        ctrl->push_button = 1;
                        ctrl->pci_config_space = 1;
                        ctrl->defeature_PHP = 1;
                        ctrl->pcix_support = 1;
                        ctrl->pcix_speed_capability = 1;
                        pci_read_config_byte(pdev, 0x41, &bus_cap);
                        if (bus_cap & 0x80) {
                                dbg("bus max supports 133MHz PCI-X\n");
                                ctrl->speed_capability = PCI_SPEED_133MHz_PCIX;
                                break;
                        }
                        if (bus_cap & 0x40) {
                                dbg("bus max supports 100MHz PCI-X\n");
                                ctrl->speed_capability = PCI_SPEED_100MHz_PCIX;
                                break;
                        }
                        if (bus_cap & 20) {
                                dbg("bus max supports 66MHz PCI-X\n");
                                ctrl->speed_capability = PCI_SPEED_66MHz_PCIX;
                                break;
                        }
                        if (bus_cap & 10) {
                                dbg("bus max supports 66MHz PCI\n");
                                ctrl->speed_capability = PCI_SPEED_66MHz;
                                break;
                        }

                        break;
                }

                switch (subsystem_deviceid) {
                case PCI_SUB_HPC_ID:
                        /* Original 6500/7000 implementation */
                        ctrl->slot_switch_type = 1;
                        ctrl->speed_capability = PCI_SPEED_33MHz;
                        ctrl->push_button = 0;
                        ctrl->pci_config_space = 1;
                        ctrl->defeature_PHP = 1;
                        ctrl->pcix_support = 0;
                        ctrl->pcix_speed_capability = 0;
                        break;
                case PCI_SUB_HPC_ID2:
                        /* First Pushbutton implementation */
                        ctrl->push_flag = 1;
                        ctrl->slot_switch_type = 1;
                        ctrl->speed_capability = PCI_SPEED_33MHz;
                        ctrl->push_button = 1;
                        ctrl->pci_config_space = 1;
                        ctrl->defeature_PHP = 1;
                        ctrl->pcix_support = 0;
                        ctrl->pcix_speed_capability = 0;
                        break;
                case PCI_SUB_HPC_ID_INTC:
                        /* Third party (6500/7000) */
                        ctrl->slot_switch_type = 1;
                        ctrl->speed_capability = PCI_SPEED_33MHz;
                        ctrl->push_button = 0;
                        ctrl->pci_config_space = 1;
                        ctrl->defeature_PHP = 1;
                        ctrl->pcix_support = 0;
                        ctrl->pcix_speed_capability = 0;
                        break;
                case PCI_SUB_HPC_ID3:
                        /* First 66 Mhz implementation */
                        ctrl->push_flag = 1;
                        ctrl->slot_switch_type = 1;
                        ctrl->speed_capability = PCI_SPEED_66MHz;
                        ctrl->push_button = 1;
                        ctrl->pci_config_space = 1;
                        ctrl->defeature_PHP = 1;
                        ctrl->pcix_support = 0;
                        ctrl->pcix_speed_capability = 0;
                        break;
                case PCI_SUB_HPC_ID4:
                        /* First PCI-X implementation, 100MHz */
                        ctrl->push_flag = 1;
                        ctrl->slot_switch_type = 1;

                        ctrl->speed_capability = PCI_SPEED_100MHz_PCIX;
                        ctrl->push_button = 1;
                        ctrl->pci_config_space = 1;
                        ctrl->defeature_PHP = 1;
                        ctrl->pcix_support = 1;
                        ctrl->pcix_speed_capability = 0;
                        break;
                default:
                        err(msg_HPC_not_supported);
                        rc = -ENODEV;
                        goto err_free_ctrl;
                }
                break;

        case PCI_VENDOR_ID_INTEL:
                /* Check for speed capability (0=33, 1=66) */
                if (subsystem_deviceid & 0x0001)
                        ctrl->speed_capability = PCI_SPEED_66MHz;
                else
                        ctrl->speed_capability = PCI_SPEED_33MHz;

                /* Check for push button */
                if (subsystem_deviceid & 0x0002)
                        ctrl->push_button = 0;
                else
                        ctrl->push_button = 1;

                /* Check for slot switch type (0=mechanical, 1=not mechanical) */
                if (subsystem_deviceid & 0x0004)
                        ctrl->slot_switch_type = 0;
                else
                        ctrl->slot_switch_type = 1;

                /* PHP Status (0=De-feature PHP, 1=Normal operation) */
                if (subsystem_deviceid & 0x0008)
                        ctrl->defeature_PHP = 1;        /* PHP supported */
                else
                        ctrl->defeature_PHP = 0;        /* PHP not supported */

                /* Alternate Base Address Register Interface
                 * (0=not supported, 1=supported)
                 */
                if (subsystem_deviceid & 0x0010)
                        ctrl->alternate_base_address = 1;
                else
                        ctrl->alternate_base_address = 0;

                /* PCI Config Space Index (0=not supported, 1=supported) */
                if (subsystem_deviceid & 0x0020)
                        ctrl->pci_config_space = 1;
                else
                        ctrl->pci_config_space = 0;

                /* PCI-X support */
                if (subsystem_deviceid & 0x0080) {
                        ctrl->pcix_support = 1;
                        if (subsystem_deviceid & 0x0040)
                                /* 133MHz PCI-X if bit 7 is 1 */
                                ctrl->pcix_speed_capability = 1;
                        else
                                /* 100MHz PCI-X if bit 7 is 1 and bit 0 is 0, */
                                /* 66MHz PCI-X if bit 7 is 1 and bit 0 is 1 */
                                ctrl->pcix_speed_capability = 0;
                } else {
                        /* Conventional PCI */
                        ctrl->pcix_support = 0;
                        ctrl->pcix_speed_capability = 0;
                }
                break;

        default:
                err(msg_HPC_not_supported);
                rc = -ENODEV;
                goto err_free_ctrl;
        }

        /* Tell the user that we found one. */
        info("Initializing the PCI hot plug controller residing on PCI bus %d\n",
                                        pdev->bus->number);

        dbg("Hotplug controller capabilities:\n");
        dbg("    speed_capability       %d\n", ctrl->speed_capability);
        dbg("    slot_switch_type       %s\n", ctrl->slot_switch_type ?
                                        "switch present" : "no switch");
        dbg("    defeature_PHP          %s\n", ctrl->defeature_PHP ?
                                        "PHP supported" : "PHP not supported");
        dbg("    alternate_base_address %s\n", ctrl->alternate_base_address ?
                                        "supported" : "not supported");
        dbg("    pci_config_space       %s\n", ctrl->pci_config_space ?
                                        "supported" : "not supported");
        dbg("    pcix_speed_capability  %s\n", ctrl->pcix_speed_capability ?
                                        "supported" : "not supported");
        dbg("    pcix_support           %s\n", ctrl->pcix_support ?
                                        "supported" : "not supported");

        ctrl->pci_dev = pdev;
        pci_set_drvdata(pdev, ctrl);

        /* make our own copy of the pci bus structure,
         * as we like tweaking it a lot */
        ctrl->pci_bus = kmalloc(sizeof(*ctrl->pci_bus), GFP_KERNEL);
        if (!ctrl->pci_bus) {
                err("out of memory\n");
                rc = -ENOMEM;
                goto err_free_ctrl;
        }
        memcpy(ctrl->pci_bus, pdev->bus, sizeof(*ctrl->pci_bus));

        ctrl->bus = pdev->bus->number;
        ctrl->rev = pdev->revision;
        dbg("bus device function rev: %d %d %d %d\n", ctrl->bus,
                PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn), ctrl->rev);

        mutex_init(&ctrl->crit_sect);
        init_waitqueue_head(&ctrl->queue);

        /* initialize our threads if they haven't already been started up */
        rc = one_time_init();
        if (rc) {
                goto err_free_bus;
        }

        dbg("pdev = %p\n", pdev);
        dbg("pci resource start %llx\n", (unsigned long long)pci_resource_start(pdev, 0));
        dbg("pci resource len %llx\n", (unsigned long long)pci_resource_len(pdev, 0));

        if (!request_mem_region(pci_resource_start(pdev, 0),
                                pci_resource_len(pdev, 0), MY_NAME)) {
                err("cannot reserve MMIO region\n");
                rc = -ENOMEM;
                goto err_free_bus;
        }

        ctrl->hpc_reg = ioremap(pci_resource_start(pdev, 0),
                                        pci_resource_len(pdev, 0));
        if (!ctrl->hpc_reg) {
                err("cannot remap MMIO region %llx @ %llx\n",
                    (unsigned long long)pci_resource_len(pdev, 0),
                    (unsigned long long)pci_resource_start(pdev, 0));
                rc = -ENODEV;
                goto err_free_mem_region;
        }

        /* Check for 66Mhz operation */
        ctrl->speed = get_controller_speed(ctrl);


        /********************************************************
         *
         *              Save configuration headers for this and
         *              subordinate PCI buses
         *
         ********************************************************/

        /* find the physical slot number of the first hot plug slot */

        /* Get slot won't work for devices behind bridges, but
         * in this case it will always be called for the "base"
         * bus/dev/func of a slot.
         * CS: this is leveraging the PCIIRQ routing code from the kernel
         * (pci-pc.c: get_irq_routing_table) */
        rc = get_slot_mapping(ctrl->pci_bus, pdev->bus->number,
                                (readb(ctrl->hpc_reg + SLOT_MASK) >> 4),
                                &(ctrl->first_slot));
        dbg("get_slot_mapping: first_slot = %d, returned = %d\n",
                                ctrl->first_slot, rc);
        if (rc) {
                err(msg_initialization_err, rc);
                goto err_iounmap;
        }

        /* Store PCI Config Space for all devices on this bus */
        rc = cpqhp_save_config(ctrl, ctrl->bus, readb(ctrl->hpc_reg + SLOT_MASK));
        if (rc) {
                err("%s: unable to save PCI configuration data, error %d\n",
                                __func__, rc);
                goto err_iounmap;
        }

        /*
         * Get IO, memory, and IRQ resources for new devices
         */
        /* The next line is required for cpqhp_find_available_resources */
        ctrl->interrupt = pdev->irq;
        if (ctrl->interrupt < 0x10) {
                cpqhp_legacy_mode = 1;
                dbg("System seems to be configured for Full Table Mapped MPS mode\n");
        }

        ctrl->cfgspc_irq = 0;
        pci_read_config_byte(pdev, PCI_INTERRUPT_LINE, &ctrl->cfgspc_irq);

        rc = cpqhp_find_available_resources(ctrl, cpqhp_rom_start);
        ctrl->add_support = !rc;
        if (rc) {
                dbg("cpqhp_find_available_resources = 0x%x\n", rc);
                err("unable to locate PCI configuration resources for hot plug add.\n");
                goto err_iounmap;
        }

        /*
         * Finish setting up the hot plug ctrl device
         */
        ctrl->slot_device_offset = readb(ctrl->hpc_reg + SLOT_MASK) >> 4;
        dbg("NumSlots %d \n", ctrl->slot_device_offset);

        ctrl->next_event = 0;

        /* Setup the slot information structures */
        rc = ctrl_slot_setup(ctrl, smbios_start, smbios_table);
        if (rc) {
                err(msg_initialization_err, 6);
                err("%s: unable to save PCI configuration data, error %d\n",
                        __func__, rc);
                goto err_iounmap;
        }

        /* Mask all general input interrupts */
        writel(0xFFFFFFFFL, ctrl->hpc_reg + INT_MASK);

        /* set up the interrupt */
        dbg("HPC interrupt = %d \n", ctrl->interrupt);
        if (request_irq(ctrl->interrupt, cpqhp_ctrl_intr,
                        IRQF_SHARED, MY_NAME, ctrl)) {
                err("Can't get irq %d for the hotplug pci controller\n",
                        ctrl->interrupt);
                rc = -ENODEV;
                goto err_iounmap;
        }

        /* Enable Shift Out interrupt and clear it, also enable SERR on power
         * fault
         */
        temp_word = readw(ctrl->hpc_reg + MISC);
        temp_word |= 0x4006;
        writew(temp_word, ctrl->hpc_reg + MISC);

        /* Changed 05/05/97 to clear all interrupts at start */
        writel(0xFFFFFFFFL, ctrl->hpc_reg + INT_INPUT_CLEAR);

        ctrl->ctrl_int_comp = readl(ctrl->hpc_reg + INT_INPUT_CLEAR);

        writel(0x0L, ctrl->hpc_reg + INT_MASK);

        if (!cpqhp_ctrl_list) {
                cpqhp_ctrl_list = ctrl;
                ctrl->next = NULL;
        } else {
                ctrl->next = cpqhp_ctrl_list;
                cpqhp_ctrl_list = ctrl;
        }

        /* turn off empty slots here unless command line option "ON" set
         * Wait for exclusive access to hardware
         */
        mutex_lock(&ctrl->crit_sect);

        num_of_slots = readb(ctrl->hpc_reg + SLOT_MASK) & 0x0F;

        /* find first device number for the ctrl */
        device = readb(ctrl->hpc_reg + SLOT_MASK) >> 4;

        while (num_of_slots) {
                dbg("num_of_slots: %d\n", num_of_slots);
                func = cpqhp_slot_find(ctrl->bus, device, 0);
                if (!func)
                        break;

                hp_slot = func->device - ctrl->slot_device_offset;
                dbg("hp_slot: %d\n", hp_slot);

                /* We have to save the presence info for these slots */
                temp_word = ctrl->ctrl_int_comp >> 16;
                func->presence_save = (temp_word >> hp_slot) & 0x01;
                func->presence_save |= (temp_word >> (hp_slot + 7)) & 0x02;

                if (ctrl->ctrl_int_comp & (0x1L << hp_slot))
                        func->switch_save = 0;
                else
                        func->switch_save = 0x10;

                if (!power_mode)
                        if (!func->is_a_board) {
                                green_LED_off(ctrl, hp_slot);
                                slot_disable(ctrl, hp_slot);
                        }

                device++;
                num_of_slots--;
        }

        if (!power_mode) {
                set_SOGO(ctrl);
                /* Wait for SOBS to be unset */
                wait_for_ctrl_irq(ctrl);
        }

        rc = init_SERR(ctrl);
        if (rc) {
                err("init_SERR failed\n");
                mutex_unlock(&ctrl->crit_sect);
                goto err_free_irq;
        }

        /* Done with exclusive hardware access */
        mutex_unlock(&ctrl->crit_sect);

        cpqhp_create_debugfs_files(ctrl);

        return 0;

err_free_irq:
        free_irq(ctrl->interrupt, ctrl);
err_iounmap:
        iounmap(ctrl->hpc_reg);
err_free_mem_region:
        release_mem_region(pci_resource_start(pdev, 0), pci_resource_len(pdev, 0));
err_free_bus:
        kfree(ctrl->pci_bus);
err_free_ctrl:
        kfree(ctrl);
err_disable_device:
        pci_disable_device(pdev);
        return rc;
}

static void __exit unload_cpqphpd(void)
{
        struct pci_func *next;
        struct pci_func *TempSlot;
        int loop;
        u32 rc;
        struct controller *ctrl;
        struct controller *tctrl;
        struct pci_resource *res;
        struct pci_resource *tres;

        rc = compaq_nvram_store(cpqhp_rom_start);

        ctrl = cpqhp_ctrl_list;

        while (ctrl) {
                if (ctrl->hpc_reg) {
                        u16 misc;
                        rc = read_slot_enable (ctrl);

                        writeb(0, ctrl->hpc_reg + SLOT_SERR);
                        writel(0xFFFFFFC0L | ~rc, ctrl->hpc_reg + INT_MASK);

                        misc = readw(ctrl->hpc_reg + MISC);
                        misc &= 0xFFFD;
                        writew(misc, ctrl->hpc_reg + MISC);
                }

                ctrl_slot_cleanup(ctrl);

                res = ctrl->io_head;
                while (res) {
                        tres = res;
                        res = res->next;
                        kfree(tres);
                }

                res = ctrl->mem_head;
                while (res) {
                        tres = res;
                        res = res->next;
                        kfree(tres);
                }

                res = ctrl->p_mem_head;
                while (res) {
                        tres = res;
                        res = res->next;
                        kfree(tres);
                }

                res = ctrl->bus_head;
                while (res) {
                        tres = res;
                        res = res->next;
                        kfree(tres);
                }

                kfree (ctrl->pci_bus);

                tctrl = ctrl;
                ctrl = ctrl->next;
                kfree(tctrl);
        }

        for (loop = 0; loop < 256; loop++) {
                next = cpqhp_slot_list[loop];
                while (next != NULL) {
                        res = next->io_head;
                        while (res) {
                                tres = res;
                                res = res->next;
                                kfree(tres);
                        }

                        res = next->mem_head;
                        while (res) {
                                tres = res;
                                res = res->next;
                                kfree(tres);
                        }

                        res = next->p_mem_head;
                        while (res) {
                                tres = res;
                                res = res->next;
                                kfree(tres);
                        }

                        res = next->bus_head;
                        while (res) {
                                tres = res;
                                res = res->next;
                                kfree(tres);
                        }

                        TempSlot = next;
                        next = next->next;
                        kfree(TempSlot);
                }
        }

        /* Stop the notification mechanism */
        if (initialized)
                cpqhp_event_stop_thread();

        /* unmap the rom address */
        if (cpqhp_rom_start)
                iounmap(cpqhp_rom_start);
        if (smbios_start)
                iounmap(smbios_start);
}

static struct pci_device_id hpcd_pci_tbl[] = {
        {
        /* handle any PCI Hotplug controller */
        .class =        ((PCI_CLASS_SYSTEM_PCI_HOTPLUG << 8) | 0x00),
        .class_mask =   ~0,

        /* no matter who makes it */
        .vendor =       PCI_ANY_ID,
        .device =       PCI_ANY_ID,
        .subvendor =    PCI_ANY_ID,
        .subdevice =    PCI_ANY_ID,

        }, { /* end: all zeroes */ }
};

MODULE_DEVICE_TABLE(pci, hpcd_pci_tbl);

static struct pci_driver cpqhpc_driver = {
        .name =         "compaq_pci_hotplug",
        .id_table =     hpcd_pci_tbl,
        .probe =        cpqhpc_probe,
        /* remove:      cpqhpc_remove_one, */
};

static int __init cpqhpc_init(void)
{
        int result;

        cpqhp_debug = debug;

        info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
        cpqhp_initialize_debugfs();
        result = pci_register_driver(&cpqhpc_driver);
        dbg("pci_register_driver = %d\n", result);
        return result;
}

static void __exit cpqhpc_cleanup(void)
{
        dbg("unload_cpqphpd()\n");
        unload_cpqphpd();

        dbg("pci_unregister_driver\n");
        pci_unregister_driver(&cpqhpc_driver);
        cpqhp_shutdown_debugfs();
}

module_init(cpqhpc_init);
module_exit(cpqhpc_cleanup);