path: root/drivers/pci/hotplug/pciehp_hpc.c

/*
 * PCI Express PCI Hot Plug 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/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/signal.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/time.h>

#include "../pci.h"
#include "pciehp.h"

static atomic_t pciehp_num_controllers = ATOMIC_INIT(0);

static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_read_config_word(dev, ctrl->cap_base + reg, value);
}

static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_read_config_dword(dev, ctrl->cap_base + reg, value);
}

static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_write_config_word(dev, ctrl->cap_base + reg, value);
}

static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_write_config_dword(dev, ctrl->cap_base + reg, value);
}

/* Power Control Command */
#define POWER_ON	0
#define POWER_OFF	PCI_EXP_SLTCTL_PCC

static irqreturn_t pcie_isr(int irq, void *dev_id);
static void start_int_poll_timer(struct controller *ctrl, int sec);

/* This is the interrupt polling timeout function. */
static void int_poll_timeout(unsigned long data)
{
	struct controller *ctrl = (struct controller *)data;

	/* Poll for interrupt events.  regs == NULL => polling */
	pcie_isr(0, ctrl);

	init_timer(&ctrl->poll_timer);
	if (!pciehp_poll_time)
		pciehp_poll_time = 2; /* default polling interval is 2 sec */

	start_int_poll_timer(ctrl, pciehp_poll_time);
}

/* This function starts the interrupt polling timer. */
static void start_int_poll_timer(struct controller *ctrl, int sec)
{
	/* Clamp to sane value */
	if ((sec <= 0) || (sec > 60))
        	sec = 2;

	ctrl->poll_timer.function = &int_poll_timeout;
	ctrl->poll_timer.data = (unsigned long)ctrl;
	ctrl->poll_timer.expires = jiffies + sec * HZ;
	add_timer(&ctrl->poll_timer);
}

static inline int pciehp_request_irq(struct controller *ctrl)
{
	int retval, irq = ctrl->pcie->irq;

	/* Install interrupt polling timer. Start with 10 sec delay */
	if (pciehp_poll_mode) {
		init_timer(&ctrl->poll_timer);
		start_int_poll_timer(ctrl, 10);
		return 0;
	}

	/* Installs the interrupt handler */
	retval = request_irq(irq, pcie_isr, IRQF_SHARED, MY_NAME,