/*
 * PCI Express 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.
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * 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>, <kristen.c.accardi@intel.com>
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/workqueue.h>
#include "../pci.h"
#include "pciehp.h"

static void interrupt_event_handler(struct work_struct *work);

static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
{
        struct event_info *info;

        info = kmalloc(sizeof(*info), GFP_ATOMIC);
        if (!info)
                return -ENOMEM;

        info->event_type = event_type;
        info->p_slot = p_slot;
        INIT_WORK(&info->work, interrupt_event_handler);

        schedule_work(&info->work);

        return 0;
}

u8 pciehp_handle_attention_button(struct slot *p_slot)
{
        u32 event_type;
        struct controller *ctrl = p_slot->ctrl;

        /* Attention Button Change */
        ctrl_dbg(ctrl, "Attention button interrupt received\n");

        /*
         *  Button pressed - See if need to TAKE ACTION!!!
         */
        ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
        event_type = INT_BUTTON_PRESS;

        queue_interrupt_event(p_slot, event_type);

        return 0;
}

u8 pciehp_handle_switch_change(struct slot *p_slot)
{
        u8 getstatus;
        u32 event_type;
        struct controller *ctrl = p_slot->ctrl;

        /* Switch Change */
        ctrl_dbg(ctrl, "Switch interrupt received\n");

        pciehp_get_latch_status(p_slot, &getstatus);
        if (getstatus) {
                /*
                 * Switch opened
                 */
                ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_SWITCH_OPEN;
        } else {
                /*
                 *  Switch closed
                 */
                ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_SWITCH_CLOSE;
        }

        queue_interrupt_event(p_slot, event_type);

        return 1;
}

u8 pciehp_handle_presence_change(struct slot *p_slot)
{
        u32 event_type;
        u8 presence_save;
        struct controller *ctrl = p_slot->ctrl;

        /* Presence Change */
        ctrl_dbg(ctrl, "Presence/Notify input change\n");

        /* Switch is open, assume a presence change
         * Save the presence state
         */
        pciehp_get_adapter_status(p_slot, &presence_save);
        if (presence_save) {
                /*
                 * Card Present
                 */
                ctrl_info(ctrl, "Card present on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_PRESENCE_ON;
        } else {
                /*
                 * Not Present
                 */
                ctrl_info(ctrl, "Card not present on Slot(%s)\n",
                          slot_name(p_slot));
                event_type = INT_PRESENCE_OFF;
        }

        queue_interrupt_event(p_slot, event_type);

        return 1;
}

u8 pciehp_handle_power_fault(struct slot *p_slot)
{
        u32 event_type;
        struct controller *ctrl = p_slot->ctrl;

        /* power fault */
        ctrl_dbg(ctrl, "Power fault interrupt received\n");

        if (!pciehp_query_power_fault(p_slot)) {
                /*
                 * power fault Cleared
                 */
                ctrl_info(ctrl, "Power fault cleared on Slot(%s)\n",
                          slot_name(p_slot));
                event_type = INT_POWER_FAULT_CLEAR;
        } else {
                /*
                 *   power fault
                 */
                ctrl_info(ctrl, "Power fault on Slot(%s)\n", slot_name(p_slot));
                event_type = INT_POWER_FAULT;
                ctrl_info(ctrl, "Power fault bit %x set\n", 0);
        }

        queue_interrupt_event(p_slot, event_type);

        return 1;
}

/* The following routines constitute the bulk of the
   hotplug controller logic
 */

static void set_slot_off(struct controller *ctrl, struct slot * pslot)
{
        /* turn off slot, turn on Amber LED, turn off Green LED if supported*/
        if (POWER_CTRL(ctrl)) {
                if (pciehp_power_off_slot(pslot)) {
                        ctrl_err(ctrl,
                                 "Issue of Slot Power Off command failed\n");
                        return;
                }
                /*
                 * After turning power off, we must wait for at least 1 second
                 * before taking any action that relies on power having been
                 * removed from the slot/adapter.
                 */
                msleep(1000);
        }

        if (PWR_LED(ctrl))
                pciehp_green_led_off(pslot);

        if (ATTN_LED(ctrl)) {
                if (pciehp_set_attention_status(pslot, 1)) {
                        ctrl_err(ctrl,
                                 "Issue of Set Attention Led command failed\n");
                        return;
                }
        }
}

/**
 * board_added - Called after a board has been added to the system.
 * @p_slot: &slot where board is added
 *
 * Turns power on for the board.
 * Configures board.
 */
static int board_added(struct slot *p_slot)
{
        int retval = 0;
        struct controller *ctrl = p_slot->ctrl;
        struct pci_bus *parent = ctrl->pcie->port->subordinate;

        if (POWER_CTRL(ctrl)) {
                /* Power on slot */
                retval = pciehp_power_on_slot(p_slot);
                if (retval)
                        return retval;
        }

        if (PWR_LED(ctrl))
                pciehp_green_led_blink(p_slot);

        /* Check link training status */
        retval = pciehp_check_link_status(ctrl);
        if (retval) {
                ctrl_err(ctrl, "Failed to check link status\n");
                set_slot_off(ctrl, p_slot);
                return retval;
        }

        /* Check for a power fault */
        if (pciehp_query_power_fault(p_slot)) {
                ctrl_dbg(ctrl, "Power fault detected\n");
                retval = -EIO;
                goto err_exit;
        }

        retval = pciehp_configure_device(p_slot);
        if (retval) {
                ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
                         pci_domain_nr(parent), parent->number);
                goto err_exit;
        }

        if (PWR_LED(ctrl))
                pciehp_green_led_on(p_slot);

        return 0;

err_exit:
        set_slot_off(ctrl, p_slot);
        return retval;
}

/**
 * remove_board - Turns off slot and LEDs
 * @p_slot: slot where board is being removed
 */
static int remove_board(struct slot *p_slot)
{
        int retval = 0;
        struct controller *ctrl = p_slot->ctrl;

        retval = pciehp_unconfigure_device(p_slot);
        if (retval)
                return retval;

        if (POWER_CTRL(ctrl)) {
                /* power off slot */
                retval = pciehp_power_off_slot(p_slot);
                if (retval) {
                        ctrl_err(ctrl,
                                 "Issue of Slot Disable command failed\n");
                        return retval;
                }
                /*
                 * After turning power off, we must wait for at least 1 second
                 * before taking any action that relies on power having been
                 * removed from the slot/adapter.
                 */
                msleep(1000);
        }

        /* turn off Green LED */
        if (PWR_LED(ctrl))
                pciehp_green_led_off(p_slot);

        return 0;
}

struct power_work_info {
        struct slot *p_slot;
        struct work_struct work;
};

/**
 * pciehp_power_thread - handle pushbutton events
 * @work: &struct work_struct describing work to be done
 *
 * Scheduled procedure to handle blocking stuff for the pushbuttons.
 * Handles all pending events and exits.
 */
static void pciehp_power_thread(struct work_struct *work)
{
        struct power_work_info *info =
                container_of(work, struct power_work_info, work);
        struct slot *p_slot = info->p_slot;

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case POWEROFF_STATE:
                mutex_unlock(&p_slot->lock);
                ctrl_dbg(p_slot->ctrl,
                         "Disabling domain:bus:device=%04x:%02x:00\n",
                         pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
                         p_slot->ctrl->pcie->port->subordinate->number);
                pciehp_disable_slot(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        case POWERON_STATE:
                mutex_unlock(&p_slot->lock);
                if (pciehp_enable_slot(p_slot) && PWR_LED(p_slot->ctrl))
                        pciehp_green_led_off(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        default:
                break;
        }
        mutex_unlock(&p_slot->lock);

        kfree(info);
}

void pciehp_queue_pushbutton_work(struct work_struct *work)
{
        struct slot *p_slot = container_of(work, struct slot, work.work);
        struct power_work_info *info;

        info = kmalloc(sizeof(*info), GFP_KERNEL);
        if (!info) {
                ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
                         __func__);
                return;
        }
        info->p_slot = p_slot;
        INIT_WORK(&info->work, pciehp_power_thread);

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case BLINKINGOFF_STATE:
                p_slot->state = POWEROFF_STATE;
                break;
        case BLINKINGON_STATE:
                p_slot->state = POWERON_STATE;
                break;
        default:
                goto out;
        }
        queue_work(pciehp_wq, &info->work);
 out:
        mutex_unlock(&p_slot->lock);
}

static int update_slot_info(struct slot *slot)
{
        struct hotplug_slot_info *info;
        int result;

        info = kmalloc(sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        pciehp_get_power_status(slot, &info->power_status);
        pciehp_get_attention_status(slot, &info->attention_status);
        pciehp_get_latch_status(slot, &info->latch_status);
        pciehp_get_adapter_status(slot, &info->adapter_status);

        result = pci_hp_change_slot_info(slot->hotplug_slot, info);
        kfree (info);
        return result;
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_button_press_event(struct slot *p_slot)
{
        struct controller *ctrl = p_slot->ctrl;
        u8 getstatus;

        switch (p_slot->state) {
        case STATIC_STATE:
                pciehp_get_power_status(p_slot, &getstatus);
                if (getstatus) {
                        p_slot->state = BLINKINGOFF_STATE;
                        ctrl_info(ctrl,
                                  "PCI slot #%s - powering off due to button "
                                  "press.\n", slot_name(p_slot));
                } else {
                        p_slot->state = BLINKINGON_STATE;
                        ctrl_info(ctrl,
                                  "PCI slot #%s - powering on due to button "
                                  "press.\n", slot_name(p_slot));
                }
                /* blink green LED and turn off amber */
                if (PWR_LED(ctrl))
                        pciehp_green_led_blink(p_slot);
                if (ATTN_LED(ctrl))
                        pciehp_set_attention_status(p_slot, 0);

                schedule_delayed_work(&p_slot->work, 5*HZ);
                break;
        case BLINKINGOFF_STATE:
        case BLINKINGON_STATE:
                /*
                 * Cancel if we are still blinking; this means that we
                 * press the attention again before the 5 sec. limit
                 * expires to cancel hot-add or hot-remove
                 */
                ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot));
                cancel_delayed_work(&p_slot->work);
                if (p_slot->state == BLINKINGOFF_STATE) {
                        if (PWR_LED(ctrl))
                                pciehp_green_led_on(p_slot);
                } else {
                        if (PWR_LED(ctrl))
                                pciehp_green_led_off(p_slot);
                }
                if (ATTN_LED(ctrl))
                        pciehp_set_attention_status(p_slot, 0);
                ctrl_info(ctrl, "PCI slot #%s - action canceled "
                          "due to button press\n", slot_name(p_slot));
                p_slot->state = STATIC_STATE;
                break;
        case POWEROFF_STATE:
        case POWERON_STATE:
                /*
                 * Ignore if the slot is on power-on or power-off state;
                 * this means that the previous attention button action
                 * to hot-add or hot-remove is undergoing
                 */
                ctrl_info(ctrl, "Button ignore on Slot(%s)\n", slot_name(p_slot));
                update_slot_info(p_slot);
                break;
        default:
                ctrl_warn(ctrl, "Not a valid state\n");
                break;
        }
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_surprise_event(struct slot *p_slot)
{
        u8 getstatus;
        struct power_work_info *info;

        info = kmalloc(sizeof(*info), GFP_KERNEL);
        if (!info) {
                ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
                         __func__);
                return;
        }
        info->p_slot = p_slot;
        INIT_WORK(&info->work, pciehp_power_thread);

        pciehp_get_adapter_status(p_slot, &getstatus);
        if (!getstatus)
                p_slot->state = POWEROFF_STATE;
        else
                p_slot->state = POWERON_STATE;

        queue_work(pciehp_wq, &info->work);
}

static void interrupt_event_handler(struct work_struct *work)
{
        struct event_info *info = container_of(work, struct event_info, work);
        struct slot *p_slot = info->p_slot;
        struct controller *ctrl = p_slot->ctrl;

        mutex_lock(&p_slot->lock);
        switch (info->event_type) {
        case INT_BUTTON_PRESS:
                handle_button_press_event(p_slot);
                break;
        case INT_POWER_FAULT:
                if (!POWER_CTRL(ctrl))
                        break;
                if (ATTN_LED(ctrl))
                        pciehp_set_attention_status(p_slot, 1);
                if (PWR_LED(ctrl))
                        pciehp_green_led_off(p_slot);
                break;
        case INT_PRESENCE_ON:
        case INT_PRESENCE_OFF:
                if (!HP_SUPR_RM(ctrl))
                        break;
                ctrl_dbg(ctrl, "Surprise Removal\n");
                update_slot_info(p_slot);
                handle_surprise_event(p_slot);
                break;
        default:
                update_slot_info(p_slot);
                break;
        }
        mutex_unlock(&p_slot->lock);

        kfree(info);
}

int pciehp_enable_slot(struct slot *p_slot)
{
        u8 getstatus = 0;
        int rc;
        struct controller *ctrl = p_slot->ctrl;

        rc = pciehp_get_adapter_status(p_slot, &getstatus);
        if (rc || !getstatus) {
                ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
                return -ENODEV;
        }
        if (MRL_SENS(p_slot->ctrl)) {
                rc = pciehp_get_latch_status(p_slot, &getstatus);
                if (rc || getstatus) {
                        ctrl_info(ctrl, "Latch open on slot(%s)\n",
                                  slot_name(p_slot));
                        return -ENODEV;
                }
        }

        if (POWER_CTRL(p_slot->ctrl)) {
                rc = pciehp_get_power_status(p_slot, &getstatus);
                if (rc || getstatus) {
                        ctrl_info(ctrl, "Already enabled on slot(%s)\n",
                                  slot_name(p_slot));
                        return -EINVAL;
                }
        }

        pciehp_get_latch_status(p_slot, &getstatus);

        rc = board_added(p_slot);
        if (rc) {
                pciehp_get_latch_status(p_slot, &getstatus);
        }

        update_slot_info(p_slot);

        return rc;
}


int pciehp_disable_slot(struct slot *p_slot)
{
        u8 getstatus = 0;
        int ret = 0;
        struct controller *ctrl = p_slot->ctrl;

        if (!p_slot->ctrl)
                return 1;

        if (!HP_SUPR_RM(p_slot->ctrl)) {
                ret = pciehp_get_adapter_status(p_slot, &getstatus);
                if (ret || !getstatus) {
                        ctrl_info(ctrl, "No adapter on slot(%s)\n",
                                  slot_name(p_slot));
                        return -ENODEV;
                }
        }

        if (MRL_SENS(p_slot->ctrl)) {
                ret = pciehp_get_latch_status(p_slot, &getstatus);
                if (ret || getstatus) {
                        ctrl_info(ctrl, "Latch open on slot(%s)\n",
                                  slot_name(p_slot));
                        return -ENODEV;
                }
        }

        if (POWER_CTRL(p_slot->ctrl)) {
                ret = pciehp_get_power_status(p_slot, &getstatus);
                if (ret || !getstatus) {
                        ctrl_info(ctrl, "Already disabled on slot(%s)\n",
                                  slot_name(p_slot));
                        return -EINVAL;
                }
        }

        ret = remove_board(p_slot);
        update_slot_info(p_slot);

        return ret;
}

int pciehp_sysfs_enable_slot(struct slot *p_slot)
{
        int retval = -ENODEV;
        struct controller *ctrl = p_slot->ctrl;

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case BLINKINGON_STATE:
                cancel_delayed_work(&p_slot->work);
        case STATIC_STATE:
                p_slot->state = POWERON_STATE;
                mutex_unlock(&p_slot->lock);
                retval = pciehp_enable_slot(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        case POWERON_STATE:
                ctrl_info(ctrl, "Slot %s is already in powering on state\n",
                          slot_name(p_slot));
                break;
        case BLINKINGOFF_STATE:
        case POWEROFF_STATE:
                ctrl_info(ctrl, "Already enabled on slot %s\n",
                          slot_name(p_slot));
                break;
        default:
                ctrl_err(ctrl, "Not a valid state on slot %s\n",
                         slot_name(p_slot));
                break;
        }
        mutex_unlock(&p_slot->lock);

        return retval;
}

int pciehp_sysfs_disable_slot(struct slot *p_slot)
{
        int retval = -ENODEV;
        struct controller *ctrl = p_slot->ctrl;

        mutex_lock(&p_slot->lock);
        switch (p_slot->state) {
        case BLINKINGOFF_STATE:
                cancel_delayed_work(&p_slot->work);
        case STATIC_STATE:
                p_slot->state = POWEROFF_STATE;
                mutex_unlock(&p_slot->lock);
                retval = pciehp_disable_slot(p_slot);
                mutex_lock(&p_slot->lock);
                p_slot->state = STATIC_STATE;
                break;
        case POWEROFF_STATE:
                ctrl_info(ctrl, "Slot %s is already in powering off state\n",
                          slot_name(p_slot));
                break;
        case BLINKINGON_STATE:
        case POWERON_STATE:
                ctrl_info(ctrl, "Already disabled on slot %s\n",
                          slot_name(p_slot));
                break;
        default:
                ctrl_err(ctrl, "Not a valid state on slot %s\n",
                         slot_name(p_slot));
                break;
        }
        mutex_unlock(&p_slot->lock);

        return retval;
}