--- /dev/null
+/*
+ * Watchdog driver for the SA11x0/PXA2xx
+ *
+ * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
+ * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * 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
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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>
+#include <linux/io.h>
+#include <linux/bitops.h>
+#include <linux/uaccess.h>
+#include <linux/timex.h>
+
+#ifdef CONFIG_ARCH_PXA
+#include <mach/regs-ost.h>
+#endif
+
+#include <mach/reset.h>
+#include <mach/hardware.h>
+
+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 <green@crimea.edu>");
+MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
+
+module_param(margin, int, 0);
+MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff