| /* |
| * Watchdog driver for the SA11x0/PXA2xx |
| * |
| * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> |
| * Based on SoftDog driver by Alan Cox <alan@redhat.com> |
| * |
| * 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 Oleg Drokin nor iXcelerator.com admit liability nor provide |
| * warranty for any of this software. This material is provided |
| * "AS-IS" and at no charge. |
| * |
| * (c) Copyright 2000 Oleg Drokin <green@crimea.edu> |
| * |
| * 27/11/2000 Initial release |
| */ |
| #include <linux/config.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/fs.h> |
| #include <linux/miscdevice.h> |
| #include <linux/watchdog.h> |
| #include <linux/init.h> |
| |
| #ifdef CONFIG_ARCH_PXA |
| #include <asm/arch/pxa-regs.h> |
| #endif |
| |
| #include <asm/hardware.h> |
| #include <asm/bitops.h> |
| #include <asm/uaccess.h> |
| |
| #define OSCR_FREQ CLOCK_TICK_RATE |
| #define SA1100_CLOSE_MAGIC (0x5afc4453) |
| |
| static unsigned long sa1100wdt_users; |
| static int expect_close; |
| static int pre_margin; |
| static int boot_status; |
| #ifdef CONFIG_WATCHDOG_NOWAYOUT |
| static int nowayout = 1; |
| #else |
| static int nowayout = 0; |
| #endif |
| |
| /* |
| * Allow only one person to hold it open |
| */ |
| static int sa1100dog_open(struct inode *inode, struct file *file) |
| { |
| nonseekable_open(inode, file); |
| if (test_and_set_bit(1,&sa1100wdt_users)) |
| return -EBUSY; |
| |
| /* Activate SA1100 Watchdog timer */ |
| OSMR3 = OSCR + pre_margin; |
| OSSR = OSSR_M3; |
| OWER = OWER_WME; |
| OIER |= OIER_E3; |
| return 0; |
| } |
| |
| /* |
| * Shut off the timer. |
| * Lock it in if it's a module and we defined ...NOWAYOUT |
| * Oddly, the watchdog can only be enabled, but we can turn off |
| * the interrupt, which appears to prevent the watchdog timing out. |
| */ |
| static int sa1100dog_release(struct inode *inode, struct file *file) |
| { |
| OSMR3 = OSCR + pre_margin; |
| |
| if (expect_close == SA1100_CLOSE_MAGIC) { |
| OIER &= ~OIER_E3; |
| } else { |
| printk(KERN_CRIT "WATCHDOG: WDT device closed unexpectedly. WDT will not stop!\n"); |
| } |
| |
| clear_bit(1, &sa1100wdt_users); |
| expect_close = 0; |
| |
| return 0; |
| } |
| |
| static ssize_t sa1100dog_write(struct file *file, const char *data, size_t len, loff_t *ppos) |
| { |
| if (len) { |
| if (!nowayout) { |
| size_t i; |
| |
| expect_close = 0; |
| |
| for (i = 0; i != len; i++) { |
| char c; |
| |
| if (get_user(c, data + i)) |
| return -EFAULT; |
| if (c == 'V') |
| expect_close = SA1100_CLOSE_MAGIC; |
| } |
| } |
| /* Refresh OSMR3 timer. */ |
| OSMR3 = OSCR + pre_margin; |
| } |
| |
| return len; |
| } |
| |
| static struct watchdog_info ident = { |
| .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | |
| WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
| .identity = "SA1100 Watchdog", |
| }; |
| |
| static int sa1100dog_ioctl(struct inode *inode, struct file *file, |
| unsigned int cmd, unsigned long arg) |
| { |
| int ret = -ENOIOCTLCMD; |
| int time; |
| |
| switch (cmd) { |
| case WDIOC_GETSUPPORT: |
| ret = copy_to_user((struct watchdog_info *)arg, &ident, |
| sizeof(ident)) ? -EFAULT : 0; |
| break; |
| |
| case WDIOC_GETSTATUS: |
| ret = put_user(0, (int *)arg); |
| break; |
| |
| case WDIOC_GETBOOTSTATUS: |
| ret = put_user(boot_status, (int *)arg); |
| break; |
| |
| case WDIOC_SETTIMEOUT: |
| ret = get_user(time, (int *)arg); |
| if (ret) |
| break; |
| |
| if (time <= 0 || time > 255) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| pre_margin = OSCR_FREQ * time; |
| OSMR3 = OSCR + pre_margin; |
| /*fall through*/ |
| |
| case WDIOC_GETTIMEOUT: |
| ret = put_user(pre_margin / OSCR_FREQ, (int *)arg); |
| break; |
| |
| case WDIOC_KEEPALIVE: |
| OSMR3 = OSCR + pre_margin; |
| ret = 0; |
| break; |
| } |
| return ret; |
| } |
| |
| static struct file_operations sa1100dog_fops = |
| { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = sa1100dog_write, |
| .ioctl = sa1100dog_ioctl, |
| .open = sa1100dog_open, |
| .release = sa1100dog_release, |
| }; |
| |
| static struct miscdevice sa1100dog_miscdev = |
| { |
| .minor = WATCHDOG_MINOR, |
| .name = "SA1100/PXA2xx watchdog", |
| .fops = &sa1100dog_fops, |
| }; |
| |
| static int margin __initdata = 60; /* (secs) Default is 1 minute */ |
| |
| static int __init sa1100dog_init(void) |
| { |
| int ret; |
| |
| /* |
| * Read the reset status, and save it for later. If |
| * we suspend, RCSR will be cleared, and the watchdog |
| * reset reason will be lost. |
| */ |
| boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0; |
| pre_margin = OSCR_FREQ * margin; |
| |
| ret = misc_register(&sa1100dog_miscdev); |
| if (ret == 0) |
| printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n", |
| margin); |
| |
| return ret; |
| } |
| |
| static void __exit sa1100dog_exit(void) |
| { |
| misc_deregister(&sa1100dog_miscdev); |
| } |
| |
| module_init(sa1100dog_init); |
| module_exit(sa1100dog_exit); |
| |
| MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>"); |
| MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog"); |
| |
| module_param(margin, int, 0); |
| MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); |
| |
| module_param(nowayout, int, 0); |
| MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |