/* * drivers/watchdog/m54xx_wdt.c * * Watchdog driver for ColdFire MCF547x & MCF548x processors * Copyright 2010 (c) Philippe De Muyter * * Adapted from the IXP4xx watchdog driver, which carries these notices: * * Author: Deepak Saxena * * Copyright 2004 (c) MontaVista, Software, Inc. * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool nowayout = WATCHDOG_NOWAYOUT; static unsigned int heartbeat = 30; /* (secs) Default is 0.5 minute */ static unsigned long wdt_status; #define WDT_IN_USE 0 #define WDT_OK_TO_CLOSE 1 static void wdt_enable(void) { unsigned int gms0; /* preserve GPIO usage, if any */ gms0 = __raw_readl(MCF_GPT_GMS0); if (gms0 & MCF_GPT_GMS_TMS_GPIO) gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK | MCF_GPT_GMS_OD); else gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD; __raw_writel(gms0, MCF_GPT_GMS0); __raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) | MCF_GPT_GCIR_CNT(0xffff), MCF_GPT_GCIR0); gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE; __raw_writel(gms0, MCF_GPT_GMS0); } static void wdt_disable(void) { unsigned int gms0; /* disable watchdog */ gms0 = __raw_readl(MCF_GPT_GMS0); gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE); __raw_writel(gms0, MCF_GPT_GMS0); } static void wdt_keepalive(void) { unsigned int gms0; gms0 = __raw_readl(MCF_GPT_GMS0); gms0 |= MCF_GPT_GMS_OCPW(0xA5); __raw_writel(gms0, MCF_GPT_GMS0); } static int m54xx_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(WDT_IN_USE, &wdt_status)) return -EBUSY; clear_bit(WDT_OK_TO_CLOSE, &wdt_status); wdt_enable(); return nonseekable_open(inode, file); } static ssize_t m54xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) { if (len) { if (!nowayout) { size_t i; clear_bit(WDT_OK_TO_CLOSE, &wdt_status); for (i = 0; i != len; i++) { char c; if (get_user(c, data + i)) return -EFAULT; if (c == 'V') set_bit(WDT_OK_TO_CLOSE, &wdt_status); } } wdt_keepalive(); } return len; } static const struct watchdog_info ident = { .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, .identity = "Coldfire M54xx Watchdog", }; static long m54xx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int ret = -ENOTTY; 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(0, (int *)arg); break; case WDIOC_KEEPALIVE: wdt_keepalive(); ret = 0; break; case WDIOC_SETTIMEOUT: ret = get_user(time, (int *)arg); if (ret) break; if (time <= 0 || time > 30) { ret = -EINVAL; break; } heartbeat = time; wdt_enable(); /* Fall through */ case WDIOC_GETTIMEOUT: ret = put_user(heartbeat, (int *)arg); break; } return ret; } static int m54xx_wdt_release(struct inode *inode, struct file *file) { if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) wdt_disable(); else { pr_crit("Device closed unexpectedly - timer will not stop\n"); wdt_keepalive(); } clear_bit(WDT_IN_USE, &wdt_status); clear_bit(WDT_OK_TO_CLOSE, &wdt_status); return 0; } static const struct file_operations m54xx_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = m54xx_wdt_write, .unlocked_ioctl = m54xx_wdt_ioctl, .open = m54xx_wdt_open, .release = m54xx_wdt_release, }; static struct miscdevice m54xx_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &m54xx_wdt_fops, }; static int __init m54xx_wdt_init(void) { if (!request_mem_region(MCF_GPT_GCIR0, 4, "Coldfire M54xx Watchdog")) { pr_warn("I/O region busy\n"); return -EBUSY; } pr_info("driver is loaded\n"); return misc_register(&m54xx_wdt_miscdev); } static void __exit m54xx_wdt_exit(void) { misc_deregister(&m54xx_wdt_miscdev); release_mem_region(MCF_GPT_GCIR0, 4); } module_init(m54xx_wdt_init); module_exit(m54xx_wdt_exit); MODULE_AUTHOR("Philippe De Muyter "); MODULE_DESCRIPTION("Coldfire M54xx Watchdog"); module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); MODULE_LICENSE("GPL"); 372b9298 /Documentation/vm parentfe6bce8d30a86c693bf7cfbf4759cbafd121289f (diff)parent39a0e975c37dee93fa1b8ea5f7eacd1c4c8a586e (diff)
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - various misc bits - most of MM (quite a lot of MM material is awaiting the merge of linux-next dependencies) - kasan - printk updates - procfs updates - MAINTAINERS - /lib updates - checkpatch updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (123 commits) init: reduce rootwait polling interval time to 5ms binfmt_elf: use vmalloc() for allocation of vma_filesz checkpatch: don't emit unified-diff error for rename-only patches checkpatch: don't check c99 types like uint8_t under tools checkpatch: avoid multiple line dereferences checkpatch: don't check .pl files, improve absolute path commit log test scripts/checkpatch.pl: fix spelling checkpatch: don't try to get maintained status when --no-tree is given lib/ida: document locking requirements a bit better lib/rbtree.c: fix typo in comment of ____rb_erase_color lib/Kconfig.debug: make CONFIG_STRICT_DEVMEM depend on CONFIG_DEVMEM MAINTAINERS: add drm and drm/i915 irc channels MAINTAINERS: add "C:" for URI for chat where developers hang out MAINTAINERS: add drm and drm/i915 bug filing info MAINTAINERS: add "B:" for URI where to file bugs get_maintainer: look for arbitrary letter prefixes in sections printk: add Kconfig option to set default console loglevel printk/sound: handle more message headers printk/btrfs: handle more message headers printk/kdb: handle more message headers ...
Diffstat (limited to 'Documentation/vm')