/*
 * 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/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include "pciehp.h"
#include <linux/interrupt.h>
#include <linux/time.h>

/* Global variables */
int pciehp_debug;
int pciehp_poll_mode;
int pciehp_poll_time;
int pciehp_force;
struct workqueue_struct *pciehp_wq;

#define DRIVER_VERSION	"0.4"
#define DRIVER_AUTHOR	"Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
#define DRIVER_DESC	"PCI Express Hot Plug Controller Driver"

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

module_param(pciehp_debug, bool, 0644);
module_param(pciehp_poll_mode, bool, 0644);
module_param(pciehp_poll_time, int, 0644);
module_param(pciehp_force, bool, 0644);
MODULE_PARM_DESC(pciehp_debug, "Debugging mode enabled or not");
MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
MODULE_PARM_DESC(pciehp_force, "Force pciehp, even if _OSC and OSHP are missing");

#define PCIE_MODULE_NAME "pciehp"

static int set_attention_status (struct hotplug_slot *slot, u8 value);
static int enable_slot		(struct hotplug_slot *slot);
static int disable_slot		(struct hotplug_slot *slot);
static int get_power_status	(struct hotplug_slot *slot, u8 *value);
static int get_attention_status	(struct hotplug_slot *slot, u8 *value);
static int get_latch_status	(struct hotplug_slot *slot, u8 *value);
static int get_adapter_status	(struct hotplug_slot *slot, u8 *value);
static int get_max_bus_speed	(struct hotplug_slot *slot, enum pci_bus_speed *value);
static int get_cur_bus_speed	(struct hotplug_slot *slot, enum pci_bus_speed *value);

static struct hotplug_slot_ops pciehp_hotplug_slot_ops = {
	.set_attention_status =	set_attention_status,
	.enable_slot =		enable_slot,
	.disable_slot =		disable_slot,
	.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,
};

/**
 * release_slot - free up the memory used by a slot
 * @hotplug_slot: slot to free
 */
static void release_slot(struct hotplug_slot *hotplug_slot)
{
	struct slot *slot = hotplug_slot->private;

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		 __func__, hotplug_slot_name(hotplug_slot));

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

static int init_slot(struct controller *ctrl)
{
	struct slot *slot = ctrl->slot;
	struct hotplug_slot *hotplug = NULL;
	struct hotplug_slot_info *info = NULL;
	char name[SLOT_NAME_SIZE];
	int retval = -ENOMEM;

	hotplug = kzalloc(sizeof(*hotplug), GFP_KERNEL);
	if (!hotplug)
		goto out;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		goto out;

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

	ctrl_dbg(ctrl, "Registering domain:bus:dev=%04x:%02x:00 sun=%x\n",
		 pci_domain_nr(ctrl->pcie->port->subordinate),
		 ctrl->pcie->port->subordinate->number, PSN(ctrl));
	retval = pci_hp_register(hotplug,
				 ctrl->pcie->port->subordinate, 0, name);
	if (retval) {
		ctrl_err(ctrl,
			 "pci_hp_register failed with error %d\n", retval);
		goto out;
	}
	get_power_status(hotplug, &info->power_status);
	get_attention_status(hotplug, &info->attention_status);
	get_latch_status(hotplug, &info->latch_status);
	get_adapter_status(hotplug, &info->adapter_status);
out:
	if (retval) {
		kfree(info);
		kfree(hotplug);
	}
	return retval;
}

static void cleanup_slot(struct controller *ctrl)
{
	pci_hp_deregister(ctrl->slot->hotplug_slot);
}

/*
 * set_attention_status - Turns the Amber LED for a slot on, off or blink
 */
static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
{
	struct slot *slot = hotplug_slot->private;

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		  __func__, slot_name(slot));

	hotplug_slot->info->attention_status = status;

	if (ATTN_LED(slot->ctrl))
		pciehp_set_attention_status(slot, status);

	return 0;
}


static int enable_slot(struct hotplug_slot *hotplug_slot)
{
	struct slot *slot = hotplug_slot->private;

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		 __func__, slot_name(slot));

	return pciehp_sysfs_enable_slot(slot);
}


static int disable_slot(struct hotplug_slot *hotplug_slot)
{
	struct slot *slot = hotplug_slot->private;

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		  __func__, slot_name(slot));

	return pciehp_sysfs_disable_slot(slot);
}

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

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		  __func__, slot_name(slot));

	retval = pciehp_get_power_status(slot, value);
	if (retval < 0)
		*value = hotplug_slot->info->power_status;

	return 0;
}

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

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		  __func__, slot_name(slot));

	retval = pciehp_get_attention_status(slot, value);
	if (retval < 0)
		*value = hotplug_slot->info->attention_status;

	return 0;
}

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

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		 __func__, slot_name(slot));

	retval = pciehp_get_latch_status(slot, value);
	if (retval < 0)
		*value = hotplug_slot->info->latch_status;

	return 0;
}

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

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		 __func__, slot_name(slot));

	retval = pciehp_get_adapter_status(slot, value);
	if (retval < 0)
		*value = hotplug_slot->info->adapter_status;

	return 0;
}

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

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		 __func__, slot_name(slot));

	retval = pciehp_get_max_link_speed(slot, value);
	if (retval < 0)
		*value = PCI_SPEED_UNKNOWN;

	return 0;
}

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

	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
		 __func__, slot_name(slot));

	retval = pciehp_get_cur_link_speed(slot, value);
	if (retval < 0)
		*value = PCI_SPEED_UNKNOWN;

	return 0;
}

static int pciehp_probe(struct pcie_device *dev)
{
	int rc;
	struct controller *ctrl;
	struct slot *slot;
	u8 value;
	struct pci_dev *pdev = dev->port;

	if (pciehp_force)
		dev_info(&dev->device,
			 "Bypassing BIOS check for pciehp use on %s\n",
			 pci_name(pdev));
	else if (pciehp_get_hp_hw_control_from_firmware(pdev))
		goto err_out_none;

	ctrl = pcie_init(dev);
	if (!ctrl) {
		dev_err(&dev->device, "Controller initialization failed\n");
		goto err_out_none;
	}
	set_service_data(dev, ctrl);

	/* Setup the slot information structures */
	rc = init_slot(ctrl);
	if (rc) {
		if (rc == -EBUSY)
			ctrl_warn(ctrl, "Slot already registered by another "
				  "hotplug driver\n");
		else
			ctrl_err(ctrl, "Slot initialization failed\n");
		goto err_out_release_ctlr;
	}

	/* Enable events after we have setup the data structures */
	rc = pcie_init_notification(ctrl);
	if (rc) {
		ctrl_err(ctrl, "Notification initialization failed\n");
		goto err_out_release_ctlr;
	}

	/* Check if slot is occupied */
	slot = ctrl->slot;
	pciehp_get_adapter_status(slot, &value);
	if (value) {
		if (pciehp_force)
			pciehp_enable_slot(slot);
	} else {
		/* Power off slot if not occupied */
		if (POWER_CTRL(ctrl)) {
			rc = pciehp_power_off_slot(slot);
			if (rc)
				goto err_out_free_ctrl_slot;
		}
	}

	return 0;

err_out_free_ctrl_slot:
	cleanup_slot(ctrl);
err_out_release_ctlr:
	pciehp_release_ctrl(ctrl);
err_out_none:
	return -ENODEV;
}

static void pciehp_remove(struct pcie_device *dev)
{
	struct controller *ctrl = get_service_data(dev);

	cleanup_slot(ctrl);
	pciehp_release_ctrl(ctrl);
}

#ifdef CONFIG_PM
static int pciehp_suspend (struct pcie_device *dev)
{
	dev_info(&dev->device, "%s ENTRY\n", __func__);
	return 0;
}

static int pciehp_resume (struct pcie_device *dev)
{
	dev_info(&dev->device, "%s ENTRY\n", __func__);
	if (pciehp_force) {
		struct controller *ctrl = get_service_data(dev);
		struct slot *slot;
		u8 status;

		/* reinitialize the chipset's event detection logic */
		pcie_enable_notification(ctrl);

		slot = ctrl->slot;

		/* Check if slot is occupied */
		pciehp_get_adapter_status(slot, &status);
		if (status)
			pciehp_enable_slot(slot);
		else
			pciehp_disable_slot(slot);
	}
	return 0;
}
#endif /* PM */

static struct pcie_port_service_driver hpdriver_portdrv = {
	.name		= PCIE_MODULE_NAME,
	.port_type	= PCIE_ANY_PORT,
	.service	= PCIE_PORT_SERVICE_HP,

	.probe		= pciehp_probe,
	.remove		= pciehp_remove,

#ifdef	CONFIG_PM
	.suspend	= pciehp_suspend,
	.resume		= pciehp_resume,
#endif	/* PM */
};

static int __init pcied_init(void)
{
	int retval = 0;

	pciehp_firmware_init();
	retval = pcie_port_service_register(&hpdriver_portdrv);
 	dbg("pcie_port_service_register = %d\n", retval);
  	info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 	if (retval)
		dbg("Failure to register service\n");
	return retval;
}

static void __exit pcied_cleanup(void)
{
	dbg("unload_pciehpd()\n");
	pcie_port_service_unregister(&hpdriver_portdrv);
	info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
}

module_init(pcied_init);
module_exit(pcied_cleanup);