text: /*
   * Standard 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/slab.h>
  #include <linux/pci.h>
  #include "../pci.h"
  #include "shpchp.h"
  
  static void interrupt_event_handler(struct work_struct *work);
  static int shpchp_enable_slot(struct slot *p_slot);
  static int shpchp_disable_slot(struct slot *p_slot);
  
  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);
  
  	queue_work(p_slot->wq, &info->work);
  
  	return 0;
  }
  
  u8 shpchp_handle_attention_button(u8 hp_slot, struct controller *ctrl)
  {
  	struct slot *p_slot;
  	u32 event_type;
  
  	/* Attention Button Change */
  	ctrl_dbg(ctrl, "Attention button interrupt received\n");
  
  	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
  	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
  
  	/*
  	 *  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 shpchp_handle_switch_change(u8 hp_slot, struct controller *ctrl)
  {
  	struct slot *p_slot;
  	u8 getstatus;
  	u32 event_type;
  
  	/* Switch Change */
  	ctrl_dbg(ctrl, "Switch interrupt received\n");
  
  	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
  	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
  	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
  	ctrl_dbg(ctrl, "Card present %x Power status %x\n",
  		 p_slot->presence_save, p_slot->pwr_save);
  
  	if (getstatus) {
  		/*
  		 * Switch opened
  		 */
  		ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
  		event_type = INT_SWITCH_OPEN;
  		if (p_slot->pwr_save && p_slot->presence_save) {
  			event_type = INT_POWER_FAULT;
  			ctrl_err(ctrl, "Surprise Removal of card\n");
  		}
  	} 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 shpchp_handle_presence_change(u8 hp_slot, struct controller *ctrl)
  {
  	struct slot *p_slot;
  	u32 event_type;
  
  	/* Presence Change */
  	ctrl_dbg(ctrl, "Presence/Notify input change\n");
  
  	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
  
  	/*
  	 * Save the presence state
  	 */
  	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
  	if (p_slot->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 shpchp_handle_power_fault(u8 hp_slot, struct controller *ctrl)
  {
  	struct slot *p_slot;
  	u32 event_type;
  
  	/* Power fault */
  	ctrl_dbg(ctrl, "Power fault interrupt received\n");
  
  	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
  
  	if (!(p_slot->hpc_ops->query_power_fault(p_slot))) {
  		/*
  		 * Power fault Cleared
  		 */
  		ctrl_info(ctrl, "Power fault cleared on Slot(%s)\n",
  			  slot_name(p_slot));
  		p_slot->status = 0x00;
  		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;
  		/* set power fault status for this board */
  		p_slot->status = 0xFF;
  		ctrl_info(ctrl, "Power fault bit %x set\n", hp_slot);
  	}
  
  	queue_interrupt_event(p_slot, event_type);
  
  	return 1;
  }
  
  /* The following routines constitute the bulk of the
     hotplug controller logic
   */
  static int change_bus_speed(struct controller *ctrl, struct slot *p_slot,
  		enum pci_bus_speed speed)
  {
  	int rc = 0;
  
  	ctrl_dbg(ctrl, "Change speed to %d\n", speed);
  	if ((rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, speed))) {
  		ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
  			 __func__);
  		return WRONG_BUS_FREQUENCY;
  	}
  	return rc;
  }
  
  static int fix_bus_speed(struct controller *ctrl, struct slot *pslot,
  		u8 flag, enum pci_bus_speed asp, enum pci_bus_speed bsp,
  		enum pci_bus_speed msp)
  {
  	int rc = 0;
  
  	/*
  	 * If other slots on the same bus are occupied, we cannot
  	 * change the bus speed.
  	 */
  	if (flag) {
  		if (asp < bsp) {
  			ctrl_err(ctrl, "Speed of bus %x and adapter %x mismatch\n",
  				 bsp, asp);
  			rc = WRONG_BUS_FREQUENCY;
  		}
  		return rc;
  	}
  
  	if (asp < msp) {
  		if (bsp != asp)
  			rc = change_bus_speed(ctrl, pslot, asp);
  	} else {
  		if (bsp != msp)
  			rc = change_bus_speed(ctrl, pslot, msp);
  	}
  	return rc;
  }
  
  /**
   * board_added - Called after a board has been added to the system.
   * @p_slot: target &slot
   *
   * Turns power on for the board.
   * Configures board.
   */
  static int board_added(struct slot *p_slot)
  {
  	u8 hp_slot;
  	u8 slots_not_empty = 0;
  	int rc = 0;
  	enum pci_bus_speed asp, bsp, msp;
  	struct controller *ctrl = p_slot->ctrl;
  	struct pci_bus *parent = ctrl->pci_dev->subordinate;
  
  	hp_slot = p_slot->device - ctrl->slot_device_offset;
  
  	ctrl_dbg(ctrl, "%s: p_slot->device, slot_offset, hp_slot = %d, %d ,%d\n",
  		 __func__, p_slot->device, ctrl->slot_device_offset, hp_slot);
  
  	/* Power on slot without connecting to bus */
  	rc = p_slot->hpc_ops->power_on_slot(p_slot);
  	if (rc) {
  		ctrl_err(ctrl, "Failed to power on slot\n");
  		return -1;
  	}
  
  	if ((ctrl->pci_dev->vendor == 0x8086) && (ctrl->pci_dev->device == 0x0332)) {
  		if ((rc = p_slot->hpc_ops->set_bus_speed_mode(p_slot, PCI_SPEED_33MHz))) {
  			ctrl_err(ctrl, "%s: Issue of set bus speed mode command failed\n",
  				 __func__);
  			return WRONG_BUS_FREQUENCY;
  		}
  
  		/* turn on board, blink green LED, turn off Amber LED */
  		if ((rc = p_slot->hpc_ops->slot_enable(p_slot))) {
  			ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
  			return rc;
  		}
  	}
  
  	rc = p_slot->hpc_ops->get_adapter_speed(p_slot, &asp);
  	if (rc) {
  		ctrl_err(ctrl, "Can't get adapter speed or bus mode mismatch\n");
  		return WRONG_BUS_FREQUENCY;
  	}
  
  	bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
  	msp = ctrl->pci_dev->subordinate->max_bus_speed;
  
  	/* Check if there are other slots or devices on the same bus */
  	if (!list_empty(&ctrl->pci_dev->subordinate->devices))
  		slots_not_empty = 1;
  
  	ctrl_dbg(ctrl, "%s: slots_not_empty %d, adapter_speed %d, bus_speed %d, max_bus_speed %d\n",
  		 __func__, slots_not_empty, asp,
  		 bsp, msp);
  
  	rc = fix_bus_speed(ctrl, p_slot, slots_not_empty, asp, bsp, msp);
  	if (rc)
  		return rc;
  
  	/* turn on board, blink green LED, turn off Amber LED */
  	if ((rc = p_slot->hpc_ops->slot_enable(p_slot))) {
  		ctrl_err(ctrl, "Issue of Slot Enable command failed\n");
  		return rc;
  	}
  
  	/* Wait for ~1 second */
  	msleep(1000);
  
  	ctrl_dbg(ctrl, "%s: slot status = %x\n", __func__, p_slot->status);
  	/* Check for a power fault */
  	if (p_slot->status == 0xFF) {
  		/* power fault occurred, but it was benign */
  		ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
  		rc = POWER_FAILURE;
  		p_slot->status = 0;
  		goto err_exit;
  	}
  
  	if (shpchp_configure_device(p_slot)) {
  		ctrl_err(ctrl, "Cannot add device at %04x:%02x:%02x\n",
  			 pci_domain_nr(parent), p_slot->bus, p_slot->device);
  		goto err_exit;
  	}
  
  	p_slot->status = 0;
  	p_slot->is_a_board = 0x01;
  	p_slot->pwr_save = 1;
  
  	p_slot->hpc_ops->green_led_on(p_slot);
  
  	return 0;
  
  err_exit:
  	/* turn off slot, turn on Amber LED, turn off Green LED */
  	rc = p_slot->hpc_ops->slot_disable(p_slot);
  	if (rc) {
  		ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
  			 __func__);
  		return rc;
  	}
  
  	return(rc);
  }
  
  
  /**
   * remove_board - Turns off slot and LEDs
   * @p_slot: target &slot
   */
  static int remove_board(struct slot *p_slot)
  {
  	struct controller *ctrl = p_slot->ctrl;
  	u8 hp_slot;
  	int rc;
  
  	if (shpchp_unconfigure_device(p_slot))
  		return(1);
  
  	hp_slot = p_slot->device - ctrl->slot_device_offset;
  	p_slot = shpchp_find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
  
  	ctrl_dbg(ctrl, "%s: hp_slot = %d\n", __func__, hp_slot);
  
  	/* Change status to shutdown */
  	if (p_slot->is_a_board)
  		p_slot->status = 0x01;
  
  	/* turn off slot, turn on Amber LED, turn off Green LED */
  	rc = p_slot->hpc_ops->slot_disable(p_slot);
  	if (rc) {
  		ctrl_err(ctrl, "%s: Issue of Slot Disable command failed\n",
  			 __func__);
  		return rc;
  	}
  
  	rc = p_slot->hpc_ops->set_attention_status(p_slot, 0);
  	if (rc) {
  		ctrl_err(ctrl, "Issue of Set Attention command failed\n");
  		return rc;
  	}
  
  	p_slot->pwr_save = 0;
  	p_slot->is_a_board = 0;
  
  	return 0;
  }
  
  
  struct pushbutton_work_info {
  	struct slot *p_slot;
  	struct work_struct work;
  };
  
  /**
   * shpchp_pushbutton_thread - handle pushbutton events
   * @work: &struct work_struct to be handled
   *
   * Scheduled procedure to handle blocking stuff for the pushbuttons.
   * Handles all pending events and exits.
   */
  static void shpchp_pushbutton_thread(struct work_struct *work)
  {
  	struct pushbutton_work_info *info =
  		container_of(work, struct pushbutton_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);
  		shpchp_disable_slot(p_slot);
  		mutex_lock(&p_slot->lock);
  		p_slot->state = STATIC_STATE;
  		break;
  	case POWERON_STATE:
  		mutex_unlock(&p_slot->lock);
  		if (shpchp_enable_slot(p_slot))
  			p_slot->hpc_ops->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 shpchp_queue_pushbutton_work(struct work_struct *work)
  {
  	struct slot *p_slot = container_of(work, struct slot, work.work);
  	struct pushbutton_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, shpchp_pushbutton_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:
  		kfree(info);
  		goto out;
  	}
  	queue_work(p_slot->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;
  
  	slot->hpc_ops->get_power_status(slot, &(info->power_status));
  	slot->hpc_ops->get_attention_status(slot, &(info->attention_status));
  	slot->hpc_ops->get_latch_status(slot, &(info->latch_status));
  	slot->hpc_ops->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)
  {
  	u8 getstatus;
  	struct controller *ctrl = p_slot->ctrl;
  
  	switch (p_slot->state) {
  	case STATIC_STATE:
  		p_slot->hpc_ops->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 */
  		p_slot->hpc_ops->green_led_blink(p_slot);
  		p_slot->hpc_ops->set_attention_status(p_slot, 0);
  
  		queue_delayed_work(p_slot->wq, &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)
  			p_slot->hpc_ops->green_led_on(p_slot);
  		else
  			p_slot->hpc_ops->green_led_off(p_slot);
  		p_slot->hpc_ops->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;
  	}
  }
  
  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;
  
  	mutex_lock(&p_slot->lock);
  	switch (info->event_type) {
  	case INT_BUTTON_PRESS:
  		handle_button_press_event(p_slot);
  		break;
  	case INT_POWER_FAULT:
  		ctrl_dbg(p_slot->ctrl, "%s: Power fault\n", __func__);
  		p_slot->hpc_ops->set_attention_status(p_slot, 1);
  		p_slot->hpc_ops->green_led_off(p_slot);
  		break;
  	default:
  		update_slot_info(p_slot);
  		break;
  	}
  	mutex_unlock(&p_slot->lock);
  
  	kfree(info);
  }
  
  
  static int shpchp_enable_slot (struct slot *p_slot)
  {
  	u8 getstatus = 0;
  	int rc, retval = -ENODEV;
  	struct controller *ctrl = p_slot->ctrl;
  
  	/* Check to see if (latch closed, card present, power off) */
  	mutex_lock(&p_slot->ctrl->crit_sect);
  	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);
  	if (rc || !getstatus) {
  		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
  		goto out;
  	}
  	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
  	if (rc || getstatus) {
  		ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
  		goto out;
  	}
  	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
  	if (rc || getstatus) {
  		ctrl_info(ctrl, "Already enabled on slot(%s)\n",
  			  slot_name(p_slot));
  		goto out;
  	}
  
  	p_slot->is_a_board = 1;
  
  	/* We have to save the presence info for these slots */
  	p_slot->hpc_ops->get_adapter_status(p_slot, &(p_slot->presence_save));
  	p_slot->hpc_ops->get_power_status(p_slot, &(p_slot->pwr_save));
  	ctrl_dbg(ctrl, "%s: p_slot->pwr_save %x\n", __func__, p_slot->pwr_save);
  	p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
  
  	if(((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD) ||
  	    (p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458))
  	     && p_slot->ctrl->num_slots == 1) {
  		/* handle amd pogo errata; this must be done before enable  */
  		amd_pogo_errata_save_misc_reg(p_slot);
  		retval = board_added(p_slot);
  		/* handle amd pogo errata; this must be done after enable  */
  		amd_pogo_errata_restore_misc_reg(p_slot);
  	} else
  		retval = board_added(p_slot);
  
  	if (retval) {
  		p_slot->hpc_ops->get_adapter_status(p_slot,
  				&(p_slot->presence_save));
  		p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
  	}
  
  	update_slot_info(p_slot);
   out:
  	mutex_unlock(&p_slot->ctrl->crit_sect);
  	return retval;
  }
  
  
  static int shpchp_disable_slot (struct slot *p_slot)
  {
  	u8 getstatus = 0;
  	int rc, retval = -ENODEV;
  	struct controller *ctrl = p_slot->ctrl;
  
  	if (!p_slot->ctrl)
  		return -ENODEV;
  
  	/* Check to see if (latch closed, card present, power on) */
  	mutex_lock(&p_slot->ctrl->crit_sect);
  
  	rc = p_slot->hpc_ops->get_adapter_status(p_slot, &getstatus);
  	if (rc || !getstatus) {
  		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
  		goto out;
  	}
  	rc = p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
  	if (rc || getstatus) {
  		ctrl_info(ctrl, "Latch open on slot(%s)\n", slot_name(p_slot));
  		goto out;
  	}
  	rc = p_slot->hpc_ops->get_power_status(p_slot, &getstatus);
  	if (rc || !getstatus) {
  		ctrl_info(ctrl, "Already disabled on slot(%s)\n",
  			  slot_name(p_slot));
  		goto out;
  	}
  
  	retval = remove_board(p_slot);
  	update_slot_info(p_slot);
   out:
  	mutex_unlock(&p_slot->ctrl->crit_sect);
  	return retval;
  }
  
  int shpchp_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 = shpchp_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 shpchp_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 = shpchp_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;
  }
  