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![Nicolas Pitre](/assets/img/avatar_default.png)
The Orion watchdog driver is also used on Kirkwood. Convention is to use orion5x for stuff specific to 88F5xxx Orion chips and simply "orion" for shared stuff across SoCs including Kirkwood. Signed-off-by: Nicolas Pitre <nico@marvell.com>
322 lines
6.8 KiB
C
322 lines
6.8 KiB
C
/*
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* drivers/watchdog/orion_wdt.c
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*
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* Watchdog driver for Orion/Kirkwood processors
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*
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* Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/miscdevice.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#include <linux/spinlock.h>
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#include <mach/bridge-regs.h>
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#include <plat/orion_wdt.h>
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/*
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* Watchdog timer block registers.
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*/
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#define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000)
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#define WDT_EN 0x0010
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#define WDT_VAL (TIMER_VIRT_BASE + 0x0024)
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#define WDT_MAX_CYCLE_COUNT 0xffffffff
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#define WDT_IN_USE 0
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#define WDT_OK_TO_CLOSE 1
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static int nowayout = WATCHDOG_NOWAYOUT;
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static int heartbeat = -1; /* module parameter (seconds) */
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static unsigned int wdt_max_duration; /* (seconds) */
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static unsigned int wdt_tclk;
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static unsigned long wdt_status;
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static spinlock_t wdt_lock;
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static void orion_wdt_ping(void)
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{
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spin_lock(&wdt_lock);
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/* Reload watchdog duration */
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writel(wdt_tclk * heartbeat, WDT_VAL);
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spin_unlock(&wdt_lock);
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}
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static void orion_wdt_enable(void)
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{
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u32 reg;
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spin_lock(&wdt_lock);
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/* Set watchdog duration */
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writel(wdt_tclk * heartbeat, WDT_VAL);
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/* Clear watchdog timer interrupt */
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reg = readl(BRIDGE_CAUSE);
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reg &= ~WDT_INT_REQ;
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writel(reg, BRIDGE_CAUSE);
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/* Enable watchdog timer */
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reg = readl(TIMER_CTRL);
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reg |= WDT_EN;
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writel(reg, TIMER_CTRL);
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/* Enable reset on watchdog */
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reg = readl(RSTOUTn_MASK);
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reg |= WDT_RESET_OUT_EN;
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writel(reg, RSTOUTn_MASK);
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spin_unlock(&wdt_lock);
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}
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static void orion_wdt_disable(void)
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{
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u32 reg;
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spin_lock(&wdt_lock);
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/* Disable reset on watchdog */
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reg = readl(RSTOUTn_MASK);
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reg &= ~WDT_RESET_OUT_EN;
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writel(reg, RSTOUTn_MASK);
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/* Disable watchdog timer */
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reg = readl(TIMER_CTRL);
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reg &= ~WDT_EN;
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writel(reg, TIMER_CTRL);
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spin_unlock(&wdt_lock);
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}
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static int orion_wdt_get_timeleft(int *time_left)
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{
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spin_lock(&wdt_lock);
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*time_left = readl(WDT_VAL) / wdt_tclk;
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spin_unlock(&wdt_lock);
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return 0;
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}
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static int orion_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(WDT_IN_USE, &wdt_status))
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return -EBUSY;
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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orion_wdt_enable();
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return nonseekable_open(inode, file);
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}
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static ssize_t orion_wdt_write(struct file *file, const char *data,
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size_t len, loff_t *ppos)
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{
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if (len) {
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if (!nowayout) {
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size_t i;
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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set_bit(WDT_OK_TO_CLOSE, &wdt_status);
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}
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}
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orion_wdt_ping();
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}
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return len;
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}
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static int orion_wdt_settimeout(int new_time)
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{
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if ((new_time <= 0) || (new_time > wdt_max_duration))
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return -EINVAL;
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/* Set new watchdog time to be used when
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* orion_wdt_enable() or orion_wdt_ping() is called. */
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heartbeat = new_time;
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return 0;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING,
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.identity = "Orion Watchdog",
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};
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static long orion_wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user((struct watchdog_info *)arg, &ident,
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sizeof(ident)) ? -EFAULT : 0;
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break;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(0, (int *)arg);
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break;
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case WDIOC_KEEPALIVE:
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orion_wdt_ping();
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ret = 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, (int *)arg);
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if (ret)
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break;
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if (orion_wdt_settimeout(time)) {
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ret = -EINVAL;
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break;
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}
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orion_wdt_ping();
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/* Fall through */
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case WDIOC_GETTIMEOUT:
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ret = put_user(heartbeat, (int *)arg);
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break;
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case WDIOC_GETTIMELEFT:
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if (orion_wdt_get_timeleft(&time)) {
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ret = -EINVAL;
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break;
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}
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ret = put_user(time, (int *)arg);
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break;
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}
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return ret;
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}
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static int orion_wdt_release(struct inode *inode, struct file *file)
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{
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if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
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orion_wdt_disable();
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else
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printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
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"timer will not stop\n");
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clear_bit(WDT_IN_USE, &wdt_status);
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clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
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return 0;
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}
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static const struct file_operations orion_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = orion_wdt_write,
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.unlocked_ioctl = orion_wdt_ioctl,
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.open = orion_wdt_open,
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.release = orion_wdt_release,
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};
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static struct miscdevice orion_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &orion_wdt_fops,
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};
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static int __devinit orion_wdt_probe(struct platform_device *pdev)
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{
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struct orion_wdt_platform_data *pdata = pdev->dev.platform_data;
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int ret;
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if (pdata) {
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wdt_tclk = pdata->tclk;
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} else {
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printk(KERN_ERR "Orion Watchdog misses platform data\n");
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return -ENODEV;
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}
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if (orion_wdt_miscdev.parent)
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return -EBUSY;
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orion_wdt_miscdev.parent = &pdev->dev;
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wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
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if (orion_wdt_settimeout(heartbeat))
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heartbeat = wdt_max_duration;
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ret = misc_register(&orion_wdt_miscdev);
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if (ret)
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return ret;
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printk(KERN_INFO "Orion Watchdog Timer: Initial timeout %d sec%s\n",
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heartbeat, nowayout ? ", nowayout" : "");
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return 0;
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}
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static int __devexit orion_wdt_remove(struct platform_device *pdev)
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{
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int ret;
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if (test_bit(WDT_IN_USE, &wdt_status)) {
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orion_wdt_disable();
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clear_bit(WDT_IN_USE, &wdt_status);
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}
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ret = misc_deregister(&orion_wdt_miscdev);
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if (!ret)
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orion_wdt_miscdev.parent = NULL;
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return ret;
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}
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static void orion_wdt_shutdown(struct platform_device *pdev)
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{
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if (test_bit(WDT_IN_USE, &wdt_status))
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orion_wdt_disable();
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}
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static struct platform_driver orion_wdt_driver = {
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.probe = orion_wdt_probe,
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.remove = __devexit_p(orion_wdt_remove),
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.shutdown = orion_wdt_shutdown,
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.driver = {
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.owner = THIS_MODULE,
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.name = "orion_wdt",
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},
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};
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static int __init orion_wdt_init(void)
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{
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spin_lock_init(&wdt_lock);
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return platform_driver_register(&orion_wdt_driver);
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}
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static void __exit orion_wdt_exit(void)
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{
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platform_driver_unregister(&orion_wdt_driver);
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}
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module_init(orion_wdt_init);
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module_exit(orion_wdt_exit);
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MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
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MODULE_DESCRIPTION("Orion Processor Watchdog");
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module_param(heartbeat, int, 0);
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MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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