pcwd_pci.c

h内核

/*
 *	Berkshire PCI-PC Watchdog Card Driver
 *
 *	(c) Copyright 2003 Wim Van Sebroeck <[e-mail]>.
 *
 *	Based on source code of the following authors:
 *	  Ken Hollis <[e-mail]>,
 *	  Lindsay Harris <[e-mail]>,
 *	  Alan Cox <[e-mail]>,
 *	  Matt Domsch <[e-mail]>,
 *	  Rob Radez <[e-mail]>
 *
 *	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.
 *
 *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
 *	provide warranty for any of this software. This material is
 *	provided "AS-IS" and at no charge.
 */

/*
 *	A bells and whistles driver is available from http://www.pcwd.de/
 *	More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/
 */

/*
 *	Includes, defines, variables, module parameters, ...
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>

#include <asm/uaccess.h>
#include <asm/io.h>

/* Module and version information */
#define WATCHDOG_VERSION "1.00"
#define WATCHDOG_DATE "12 Jun 2004"
#define WATCHDOG_DRIVER_NAME "PCI-PC Watchdog"
#define WATCHDOG_NAME "pcwd_pci"
#define PFX WATCHDOG_NAME ": "
#define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" WATCHDOG_DATE ")\n"

/* Stuff for the PCI ID's  */
#ifndef PCI_VENDOR_ID_QUICKLOGIC
#define PCI_VENDOR_ID_QUICKLOGIC    0x11e3
#endif

#ifndef PCI_DEVICE_ID_WATCHDOG_PCIPCWD
#define PCI_DEVICE_ID_WATCHDOG_PCIPCWD 0x5030
#endif

/*
 * These are the defines that describe the control status bits for the
 * PCI-PC Watchdog card.
 */
#define WD_PCI_WTRP             0x01	/* Watchdog Trip status */
#define WD_PCI_HRBT             0x02	/* Watchdog Heartbeat */
#define WD_PCI_TTRP             0x04	/* Temperature Trip status */

/* according to documentation max. time to process a command for the pci
 * watchdog card is 100 ms, so we give it 150 ms to do it's job */
#define PCI_COMMAND_TIMEOUT	150

/* Watchdog's internal commands */
#define CMD_GET_STATUS			0x04
#define CMD_GET_FIRMWARE_VERSION	0x08
#define CMD_READ_WATCHDOG_TIMEOUT	0x18
#define CMD_WRITE_WATCHDOG_TIMEOUT	0x19

/* We can only use 1 card due to the /dev/watchdog restriction */
static int cards_found;

/* internal variables */
static int temp_panic;
static unsigned long is_active;
static char expect_release;
static struct {
	int supports_temp;	/* Wether or not the card has a temperature device */
	int boot_status;	/* The card's boot status */
	unsigned long io_addr;	/* The cards I/O address */
	spinlock_t io_lock;
	struct pci_dev *pdev;
} pcipcwd_private;

/* module parameters */
#define WATCHDOG_HEARTBEAT 2	/* 2 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");

#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
#else
static int nowayout = 0;
#endif

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

/*
 *	Internal functions
 */

static int send_command(int cmd, int *msb, int *lsb)
{
	int got_response, count;

	spin_lock(&pcipcwd_private.io_lock);
	/* If a command requires data it should be written first.
	 * Data for commands with 8 bits of data should be written to port 4.
	 * Commands with 16 bits of data, should be written as LSB to port 4
	 * and MSB to port 5.
	 * After the required data has been written then write the command to
	 * port 6. */
	outb_p(*lsb, pcipcwd_private.io_addr + 4);
	outb_p(*msb, pcipcwd_private.io_addr + 5);
	outb_p(cmd, pcipcwd_private.io_addr + 6);

	/* wait till the pci card processed the command, signaled by
	 * the WRSP bit in port 2 and give it a max. timeout of
	 * PCI_COMMAND_TIMEOUT to process */
	got_response = inb_p(pcipcwd_private.io_addr + 2) & 0x40;
	for (count = 0; (count < PCI_COMMAND_TIMEOUT) && (!got_response); count++) {
		mdelay(1);
		got_response = inb_p(pcipcwd_private.io_addr + 2) & 0x40;
	}

	if (got_response) {
		/* read back response */
		*lsb = inb_p(pcipcwd_private.io_addr + 4);
		*msb = inb_p(pcipcwd_private.io_addr + 5);

		/* clear WRSP bit */
		inb_p(pcipcwd_private.io_addr + 6);
	}
	spin_unlock(&pcipcwd_private.io_lock);

	return got_response;
}

static int pcipcwd_start(void)
{
	int stat_reg;

	spin_lock(&pcipcwd_private.io_lock);
	outb_p(0x00, pcipcwd_private.io_addr + 3);
	udelay(1000);

	stat_reg = inb_p(pcipcwd_private.io_addr + 2);
	spin_unlock(&pcipcwd_private.io_lock);

	if (stat_reg & 0x10) {
		printk(KERN_ERR PFX "Card timer not enabled\n");
		return -1;
	}

	return 0;
}

static int pcipcwd_stop(void)
{
	int stat_reg;

	spin_lock(&pcipcwd_private.io_lock);
	outb_p(0xA5, pcipcwd_private.io_addr + 3);
	udelay(1000);

	outb_p(0xA5, pcipcwd_private.io_addr + 3);
	udelay(1000);

	stat_reg = inb_p(pcipcwd_private.io_addr + 2);
	spin_unlock(&pcipcwd_private.io_lock);

	if (!(stat_reg & 0x10)) {
		printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
		return -1;
	}

	return 0;
}

static int pcipcwd_keepalive(void)
{
	/* Re-trigger watchdog by writing to port 0 */
	outb_p(0x42, pcipcwd_private.io_addr);
	return 0;
}

static int pcipcwd_set_heartbeat(int t)
{
	int t_msb = t / 256;
	int t_lsb = t % 256;

	if ((t < 0x0001) || (t > 0xFFFF))
		return -EINVAL;

	/* Write new heartbeat to watchdog */
	send_command(CMD_WRITE_WATCHDOG_TIMEOUT, &t_msb, &t_lsb);

	heartbeat = t;
	return 0;
}

static int pcipcwd_get_status(int *status)
{
	int new_status;

	*status=0;
	new_status = inb_p(pcipcwd_private.io_addr + 1);
	if (new_status & WD_PCI_WTRP)
		*status |= WDIOF_CARDRESET;
	if (new_status & WD_PCI_TTRP) {
		*status |= WDIOF_OVERHEAT;
		if (temp_panic)
			panic(PFX "Temperature overheat trip!\n");
	}

	return 0;
}

static int pcipcwd_clear_status(void)
{
	outb_p(0x01, pcipcwd_private.io_addr + 1);
	return 0;
}

static int pcipcwd_get_temperature(int *temperature)
{
	*temperature = 0;
	if (!pcipcwd_private.supports_temp)
		return -ENODEV;

	/*
	 * Convert celsius to fahrenheit, since this was
	 * the decided 'standard' for this return value.
	 */
	*temperature = ((inb_p(pcipcwd_private.io_addr)) * 9 / 5) + 32;

	return 0;
}

/*
 *	/dev/watchdog handling
 */

static ssize_t pcipcwd_write(struct file *file, const char __user *data,
			      size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* note: just in case someone wrote the magic character
			 * five months ago... */
			expect_release = 0;

			/* scan to see whether or not we got the magic character */
			for (i = 0; i != len; i++) {
				char c;
				if(get_user(c, data+i))
					return -EFAULT;
				if (c == 'V')
					expect_release = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		pcipcwd_keepalive();
	}
	return len;
}

static int pcipcwd_ioctl(struct inode *inode, struct file *file,
			  unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
		.options =		WDIOF_OVERHEAT |
					WDIOF_CARDRESET |
					WDIOF_KEEPALIVEPING |
					WDIOF_SETTIMEOUT |
					WDIOF_MAGICCLOSE,
		.firmware_version =	1,
		.identity =		WATCHDOG_DRIVER_NAME,
	};

	switch (cmd) {
		case WDIOC_GETSUPPORT:
			return copy_to_user(argp, &ident,
				sizeof (ident)) ? -EFAULT : 0;

		case WDIOC_GETSTATUS:
		{
			int status;

			pcipcwd_get_status(&status);

			return put_user(status, p);
		}

		case WDIOC_GETBOOTSTATUS:
			return put_user(pcipcwd_private.boot_status, p);

		case WDIOC_GETTEMP:
		{
			int temperature;

			if (pcipcwd_get_temperature(&temperature))
				return -EFAULT;

			return put_user(temperature, p);
		}

		case WDIOC_KEEPALIVE:
			pcipcwd_keepalive();
			return 0;

		case WDIOC_SETOPTIONS:
		{
			int new_options, retval = -EINVAL;

			if (get_user (new_options, p))