X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fwatchdog%2Fsa1100_wdt.c;fp=kernel%2Fdrivers%2Fwatchdog%2Fsa1100_wdt.c;h=e1d39a1e9628dd4ce177b197032bb716083b7506;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/watchdog/sa1100_wdt.c b/kernel/drivers/watchdog/sa1100_wdt.c new file mode 100644 index 000000000..e1d39a1e9 --- /dev/null +++ b/kernel/drivers/watchdog/sa1100_wdt.c @@ -0,0 +1,195 @@ +/* + * Watchdog driver for the SA11x0/PXA2xx + * + * (c) Copyright 2000 Oleg Drokin + * Based on SoftDog driver by Alan Cox + * + * 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 + * + * 27/11/2000 Initial release + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_ARCH_PXA +#include +#endif + +#include +#include + +static unsigned long oscr_freq; +static unsigned long sa1100wdt_users; +static unsigned int pre_margin; +static int boot_status; + +/* + * Allow only one person to hold it open + */ +static int sa1100dog_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(1, &sa1100wdt_users)) + return -EBUSY; + + /* Activate SA1100 Watchdog timer */ + writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); + writel_relaxed(OSSR_M3, OSSR); + writel_relaxed(OWER_WME, OWER); + writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER); + return nonseekable_open(inode, file); +} + +/* + * The watchdog cannot be disabled. + * + * Previous comments suggested that turning off the interrupt by + * clearing OIER[E3] would prevent the watchdog timing out but this + * does not appear to be true (at least on the PXA255). + */ +static int sa1100dog_release(struct inode *inode, struct file *file) +{ + pr_crit("Device closed - timer will not stop\n"); + clear_bit(1, &sa1100wdt_users); + return 0; +} + +static ssize_t sa1100dog_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + if (len) + /* Refresh OSMR3 timer. */ + writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); + return len; +} + +static const struct watchdog_info ident = { + .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT + | WDIOF_KEEPALIVEPING, + .identity = "SA1100/PXA255 Watchdog", + .firmware_version = 1, +}; + +static long sa1100dog_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int ret = -ENOTTY; + int time; + void __user *argp = (void __user *)arg; + int __user *p = argp; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user(argp, &ident, + sizeof(ident)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + ret = put_user(0, p); + break; + + case WDIOC_GETBOOTSTATUS: + ret = put_user(boot_status, p); + break; + + case WDIOC_KEEPALIVE: + writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); + ret = 0; + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(time, p); + if (ret) + break; + + if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) { + ret = -EINVAL; + break; + } + + pre_margin = oscr_freq * time; + writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); + /*fall through*/ + + case WDIOC_GETTIMEOUT: + ret = put_user(pre_margin / oscr_freq, p); + break; + } + return ret; +} + +static const struct file_operations sa1100dog_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = sa1100dog_write, + .unlocked_ioctl = sa1100dog_ioctl, + .open = sa1100dog_open, + .release = sa1100dog_release, +}; + +static struct miscdevice sa1100dog_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &sa1100dog_fops, +}; + +static int margin __initdata = 60; /* (secs) Default is 1 minute */ + +static int __init sa1100dog_init(void) +{ + int ret; + + oscr_freq = get_clock_tick_rate(); + + /* + * 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 = (reset_status & RESET_STATUS_WATCHDOG) ? + WDIOF_CARDRESET : 0; + pre_margin = oscr_freq * margin; + + ret = misc_register(&sa1100dog_miscdev); + if (ret == 0) + pr_info("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 "); +MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog"); + +module_param(margin, int, 0); +MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); + +MODULE_LICENSE("GPL");