--- /dev/null
+/*
+ * PNX833x Hardware Watchdog Driver
+ * Copyright 2008 NXP Semiconductors
+ * Daniel Laird <daniel.j.laird@nxp.com>
+ * Andre McCurdy <andre.mccurdy@nxp.com>
+ *
+ * Heavily based upon - IndyDog 0.3
+ * A Hardware Watchdog Device for SGI IP22
+ *
+ * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
+ *
+ * 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.
+ *
+ * based on softdog.c by Alan Cox <alan@redhat.com>
+ */
+
+#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/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <asm/mach-pnx833x/pnx833x.h>
+
+#define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */
+#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
+#define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY)
+#define PNX_TIMEOUT_VALUE 2040000000U
+
+/** CONFIG block */
+#define PNX833X_CONFIG (0x07000U)
+#define PNX833X_CONFIG_CPU_WATCHDOG (0x54)
+#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)
+#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)
+
+/** RESET block */
+#define PNX833X_RESET (0x08000U)
+#define PNX833X_RESET_CONFIG (0x08)
+
+static int pnx833x_wdt_alive;
+
+/* Set default timeout in MHZ.*/
+static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT;
+module_param(pnx833x_wdt_timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
+ __MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds).");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+#define START_DEFAULT 1
+static int start_enabled = START_DEFAULT;
+module_param(start_enabled, int, 0);
+MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
+ "(default=" __MODULE_STRING(START_DEFAULT) ")");
+
+static void pnx833x_wdt_start(void)
+{
+ /* Enable watchdog causing reset. */
+ PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1;
+ /* Set timeout.*/
+ PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+ /* Enable watchdog. */
+ PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1;
+
+ pr_info("Started watchdog timer\n");
+}
+
+static void pnx833x_wdt_stop(void)
+{
+ /* Disable watchdog causing reset. */
+ PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
+ /* Disable watchdog.*/
+ PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;
+
+ pr_info("Stopped watchdog timer\n");
+}
+
+static void pnx833x_wdt_ping(void)
+{
+ PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
+}
+
+/*
+ * Allow only one person to hold it open
+ */
+static int pnx833x_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &pnx833x_wdt_alive))
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate timer */
+ if (!start_enabled)
+ pnx833x_wdt_start();
+
+ pnx833x_wdt_ping();
+
+ pr_info("Started watchdog timer\n");
+
+ return nonseekable_open(inode, file);
+}
+
+static int pnx833x_wdt_release(struct inode *inode, struct file *file)
+{
+ /* Shut off the timer.
+ * Lock it in if it's a module and we defined ...NOWAYOUT */
+ if (!nowayout)
+ pnx833x_wdt_stop(); /* Turn the WDT off */
+
+ clear_bit(0, &pnx833x_wdt_alive);
+ return 0;
+}
+
+static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+ /* Refresh the timer. */
+ if (len)
+ pnx833x_wdt_ping();
+
+ return len;
+}
+
+static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int options, new_timeout = 0;
+ uint32_t timeout, timeout_left = 0;
+
+ static const struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
+ .firmware_version = 0,
+ .identity = "Hardware Watchdog for PNX833x",
+ };
+
+ switch (cmd) {
+ default:
+ return -ENOTTY;
+
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user((struct watchdog_info *)arg,
+ &ident, sizeof(ident)))
+ return -EFAULT;
+ return 0;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, (int *)arg);
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(options, (int *)arg))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD)
+ pnx833x_wdt_stop();
+
+ if (options & WDIOS_ENABLECARD)
+ pnx833x_wdt_start();
+
+ return 0;
+
+ case WDIOC_KEEPALIVE:
+ pnx833x_wdt_ping();
+ return 0;
+
+ case WDIOC_SETTIMEOUT:
+ {
+ if (get_user(new_timeout, (int *)arg))
+ return -EFAULT;
+
+ pnx833x_wdt_timeout = new_timeout;
+ PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
+ return put_user(new_timeout, (int *)arg);
+ }
+
+ case WDIOC_GETTIMEOUT:
+ timeout = PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
+ return put_user(timeout, (int *)arg);
+
+ case WDIOC_GETTIMELEFT:
+ timeout_left = PNX833X_REG(PNX833X_CONFIG +
+ PNX833X_CONFIG_CPU_WATCHDOG);
+ return put_user(timeout_left, (int *)arg);
+
+ }
+}
+
+static int pnx833x_wdt_notify_sys(struct notifier_block *this,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ pnx833x_wdt_stop(); /* Turn the WDT off */
+
+ return NOTIFY_DONE;
+}
+
+static const struct file_operations pnx833x_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = pnx833x_wdt_write,
+ .unlocked_ioctl = pnx833x_wdt_ioctl,
+ .open = pnx833x_wdt_open,
+ .release = pnx833x_wdt_release,
+};
+
+static struct miscdevice pnx833x_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &pnx833x_wdt_fops,
+};
+
+static struct notifier_block pnx833x_wdt_notifier = {
+ .notifier_call = pnx833x_wdt_notify_sys,
+};
+
+static int __init watchdog_init(void)
+{
+ int ret, cause;
+
+ /* Lets check the reason for the reset.*/
+ cause = PNX833X_REG(PNX833X_RESET);
+ /*If bit 31 is set then watchdog was cause of reset.*/
+ if (cause & 0x80000000) {
+ pr_info("The system was previously reset due to the watchdog firing - please investigate...\n");
+ }
+
+ ret = register_reboot_notifier(&pnx833x_wdt_notifier);
+ if (ret) {
+ pr_err("cannot register reboot notifier (err=%d)\n", ret);
+ return ret;
+ }
+
+ ret = misc_register(&pnx833x_wdt_miscdev);
+ if (ret) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ unregister_reboot_notifier(&pnx833x_wdt_notifier);
+ return ret;
+ }
+
+ pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n");
+
+ if (start_enabled)
+ pnx833x_wdt_start();
+
+ return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+ misc_deregister(&pnx833x_wdt_miscdev);
+ unregister_reboot_notifier(&pnx833x_wdt_notifier);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Daniel Laird/Andre McCurdy");
+MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff