193 lines
4.4 KiB
C
193 lines
4.4 KiB
C
/*
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* Watchdog driver for the SA11x0/PXA2xx
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*
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* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
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* Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
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* warranty for any of this software. This material is provided
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* "AS-IS" and at no charge.
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*
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* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
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*
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* 27/11/2000 Initial release
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/bitops.h>
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#include <linux/uaccess.h>
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#include <linux/timex.h>
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#ifdef CONFIG_ARCH_PXA
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#include <mach/regs-ost.h>
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#endif
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#include <mach/reset.h>
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#include <mach/hardware.h>
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static unsigned long oscr_freq;
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static unsigned long sa1100wdt_users;
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static int pre_margin;
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static int boot_status;
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/*
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* Allow only one person to hold it open
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*/
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static int sa1100dog_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(1, &sa1100wdt_users))
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return -EBUSY;
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/* Activate SA1100 Watchdog timer */
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OSMR3 = OSCR + pre_margin;
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OSSR = OSSR_M3;
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OWER = OWER_WME;
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OIER |= OIER_E3;
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return nonseekable_open(inode, file);
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}
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/*
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* The watchdog cannot be disabled.
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*
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* Previous comments suggested that turning off the interrupt by
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* clearing OIER[E3] would prevent the watchdog timing out but this
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* does not appear to be true (at least on the PXA255).
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*/
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static int sa1100dog_release(struct inode *inode, struct file *file)
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{
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printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
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clear_bit(1, &sa1100wdt_users);
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return 0;
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}
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static ssize_t sa1100dog_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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if (len)
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/* Refresh OSMR3 timer. */
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OSMR3 = OSCR + pre_margin;
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return len;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
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| WDIOF_KEEPALIVEPING,
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.identity = "SA1100/PXA255 Watchdog",
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};
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static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user(argp, &ident,
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sizeof(ident)) ? -EFAULT : 0;
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break;
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case WDIOC_GETSTATUS:
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ret = put_user(0, p);
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break;
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(boot_status, p);
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break;
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case WDIOC_KEEPALIVE:
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OSMR3 = OSCR + pre_margin;
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ret = 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, p);
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if (ret)
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break;
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if (time <= 0 || time > 255) {
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ret = -EINVAL;
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break;
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}
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pre_margin = oscr_freq * time;
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OSMR3 = OSCR + pre_margin;
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/*fall through*/
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case WDIOC_GETTIMEOUT:
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ret = put_user(pre_margin / oscr_freq, p);
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break;
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}
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return ret;
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}
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static const struct file_operations sa1100dog_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = sa1100dog_write,
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.unlocked_ioctl = sa1100dog_ioctl,
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.open = sa1100dog_open,
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.release = sa1100dog_release,
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};
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static struct miscdevice sa1100dog_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &sa1100dog_fops,
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};
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static int margin __initdata = 60; /* (secs) Default is 1 minute */
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static int __init sa1100dog_init(void)
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{
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int ret;
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oscr_freq = get_clock_tick_rate();
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/*
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* Read the reset status, and save it for later. If
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* we suspend, RCSR will be cleared, and the watchdog
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* reset reason will be lost.
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*/
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boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
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WDIOF_CARDRESET : 0;
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pre_margin = oscr_freq * margin;
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ret = misc_register(&sa1100dog_miscdev);
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if (ret == 0)
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printk(KERN_INFO
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"SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
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margin);
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return ret;
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}
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static void __exit sa1100dog_exit(void)
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{
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misc_deregister(&sa1100dog_miscdev);
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}
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module_init(sa1100dog_init);
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module_exit(sa1100dog_exit);
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MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
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MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
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module_param(margin, int, 0);
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MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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