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path: root/drivers/watchdog/orion_wdt.c
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-rw-r--r--drivers/watchdog/orion_wdt.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
new file mode 100644
index 0000000..2d9fb96
--- /dev/null
+++ b/drivers/watchdog/orion_wdt.c
@@ -0,0 +1,322 @@
+/*
+ * drivers/watchdog/orion_wdt.c
+ *
+ * Watchdog driver for Orion/Kirkwood processors
+ *
+ * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
+ *
+ * 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.
+ */
+
+#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/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/init.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <mach/bridge-regs.h>
+#include <plat/orion_wdt.h>
+
+/*
+ * Watchdog timer block registers.
+ */
+#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
+#define WDT_EN 0x0010
+#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
+
+#define WDT_MAX_CYCLE_COUNT 0xffffffff
+#define WDT_IN_USE 0
+#define WDT_OK_TO_CLOSE 1
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat = -1; /* module parameter (seconds) */
+static unsigned int wdt_max_duration; /* (seconds) */
+static unsigned int wdt_tclk;
+static unsigned long wdt_status;
+static spinlock_t wdt_lock;
+
+static void orion_wdt_ping(void)
+{
+ spin_lock(&wdt_lock);
+
+ /* Reload watchdog duration */
+ writel(wdt_tclk * heartbeat, WDT_VAL);
+
+ spin_unlock(&wdt_lock);
+}
+
+static void orion_wdt_enable(void)
+{
+ u32 reg;
+
+ spin_lock(&wdt_lock);
+
+ /* Set watchdog duration */
+ writel(wdt_tclk * heartbeat, WDT_VAL);
+
+ /* Clear watchdog timer interrupt */
+ reg = readl(BRIDGE_CAUSE);
+ reg &= ~WDT_INT_REQ;
+ writel(reg, BRIDGE_CAUSE);
+
+ /* Enable watchdog timer */
+ reg = readl(TIMER_CTRL);
+ reg |= WDT_EN;
+ writel(reg, TIMER_CTRL);
+
+ /* Enable reset on watchdog */
+ reg = readl(RSTOUTn_MASK);
+ reg |= WDT_RESET_OUT_EN;
+ writel(reg, RSTOUTn_MASK);
+
+ spin_unlock(&wdt_lock);
+}
+
+static void orion_wdt_disable(void)
+{
+ u32 reg;
+
+ spin_lock(&wdt_lock);
+
+ /* Disable reset on watchdog */
+ reg = readl(RSTOUTn_MASK);
+ reg &= ~WDT_RESET_OUT_EN;
+ writel(reg, RSTOUTn_MASK);
+
+ /* Disable watchdog timer */
+ reg = readl(TIMER_CTRL);
+ reg &= ~WDT_EN;
+ writel(reg, TIMER_CTRL);
+
+ spin_unlock(&wdt_lock);
+}
+
+static int orion_wdt_get_timeleft(int *time_left)
+{
+ spin_lock(&wdt_lock);
+ *time_left = readl(WDT_VAL) / wdt_tclk;
+ spin_unlock(&wdt_lock);
+ return 0;
+}
+
+static int orion_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);
+ orion_wdt_enable();
+ return nonseekable_open(inode, file);
+}
+
+static ssize_t orion_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);
+ }
+ }
+ orion_wdt_ping();
+ }
+ return len;
+}
+
+static int orion_wdt_settimeout(int new_time)
+{
+ if ((new_time <= 0) || (new_time > wdt_max_duration))
+ return -EINVAL;
+
+ /* Set new watchdog time to be used when
+ * orion_wdt_enable() or orion_wdt_ping() is called. */
+ heartbeat = new_time;
+ return 0;
+}
+
+static const struct watchdog_info ident = {
+ .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING,
+ .identity = "Orion Watchdog",
+};
+
+static long orion_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:
+ case WDIOC_GETBOOTSTATUS:
+ ret = put_user(0, (int *)arg);
+ break;
+
+ case WDIOC_KEEPALIVE:
+ orion_wdt_ping();
+ ret = 0;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ ret = get_user(time, (int *)arg);
+ if (ret)
+ break;
+
+ if (orion_wdt_settimeout(time)) {
+ ret = -EINVAL;
+ break;
+ }
+ orion_wdt_ping();
+ /* Fall through */
+
+ case WDIOC_GETTIMEOUT:
+ ret = put_user(heartbeat, (int *)arg);
+ break;
+
+ case WDIOC_GETTIMELEFT:
+ if (orion_wdt_get_timeleft(&time)) {
+ ret = -EINVAL;
+ break;
+ }
+ ret = put_user(time, (int *)arg);
+ break;
+ }
+ return ret;
+}
+
+static int orion_wdt_release(struct inode *inode, struct file *file)
+{
+ if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
+ orion_wdt_disable();
+ else
+ printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
+ "timer will not stop\n");
+ clear_bit(WDT_IN_USE, &wdt_status);
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+ return 0;
+}
+
+
+static const struct file_operations orion_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = orion_wdt_write,
+ .unlocked_ioctl = orion_wdt_ioctl,
+ .open = orion_wdt_open,
+ .release = orion_wdt_release,
+};
+
+static struct miscdevice orion_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &orion_wdt_fops,
+};
+
+static int __devinit orion_wdt_probe(struct platform_device *pdev)
+{
+ struct orion_wdt_platform_data *pdata = pdev->dev.platform_data;
+ int ret;
+
+ if (pdata) {
+ wdt_tclk = pdata->tclk;
+ } else {
+ printk(KERN_ERR "Orion Watchdog misses platform data\n");
+ return -ENODEV;
+ }
+
+ if (orion_wdt_miscdev.parent)
+ return -EBUSY;
+ orion_wdt_miscdev.parent = &pdev->dev;
+
+ wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
+ if (orion_wdt_settimeout(heartbeat))
+ heartbeat = wdt_max_duration;
+
+ ret = misc_register(&orion_wdt_miscdev);
+ if (ret)
+ return ret;
+
+ printk(KERN_INFO "Orion Watchdog Timer: Initial timeout %d sec%s\n",
+ heartbeat, nowayout ? ", nowayout" : "");
+ return 0;
+}
+
+static int __devexit orion_wdt_remove(struct platform_device *pdev)
+{
+ int ret;
+
+ if (test_bit(WDT_IN_USE, &wdt_status)) {
+ orion_wdt_disable();
+ clear_bit(WDT_IN_USE, &wdt_status);
+ }
+
+ ret = misc_deregister(&orion_wdt_miscdev);
+ if (!ret)
+ orion_wdt_miscdev.parent = NULL;
+
+ return ret;
+}
+
+static void orion_wdt_shutdown(struct platform_device *pdev)
+{
+ if (test_bit(WDT_IN_USE, &wdt_status))
+ orion_wdt_disable();
+}
+
+static struct platform_driver orion_wdt_driver = {
+ .probe = orion_wdt_probe,
+ .remove = __devexit_p(orion_wdt_remove),
+ .shutdown = orion_wdt_shutdown,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "orion_wdt",
+ },
+};
+
+static int __init orion_wdt_init(void)
+{
+ spin_lock_init(&wdt_lock);
+ return platform_driver_register(&orion_wdt_driver);
+}
+
+static void __exit orion_wdt_exit(void)
+{
+ platform_driver_unregister(&orion_wdt_driver);
+}
+
+module_init(orion_wdt_init);
+module_exit(orion_wdt_exit);
+
+MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
+MODULE_DESCRIPTION("Orion Processor Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);