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path: root/drivers/char/watchdog/sa1100_wdt.c
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Diffstat (limited to 'drivers/char/watchdog/sa1100_wdt.c')
-rw-r--r--drivers/char/watchdog/sa1100_wdt.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/char/watchdog/sa1100_wdt.c b/drivers/char/watchdog/sa1100_wdt.c
new file mode 100644
index 00000000000..34e8f7b15e3
--- /dev/null
+++ b/drivers/char/watchdog/sa1100_wdt.c
@@ -0,0 +1,223 @@
+/*
+ * 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);