* Watchdog driver for ARM SP805 watchdog module
*
* Copyright (C) 2010 ST Microelectronics
- * Viresh Kumar<viresh.kumar@st.com>
+ * Viresh Kumar <viresh.linux@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2 or later. This program is licensed "as is" without any
#include <linux/amba/bus.h>
#include <linux/bitops.h>
#include <linux/clk.h>
-#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/math64.h>
-#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
-#include <linux/uaccess.h>
#include <linux/watchdog.h>
/* default timeout in seconds */
/**
* struct sp805_wdt: sp805 wdt device structure
+ * @wdd: instance of struct watchdog_device
* @lock: spin lock protecting dev structure and io access
* @base: base address of wdt
* @clk: clock structure of wdt
* @timeout: current programmed timeout
*/
struct sp805_wdt {
+ struct watchdog_device wdd;
spinlock_t lock;
void __iomem *base;
struct clk *clk;
struct amba_device *adev;
- unsigned long status;
- #define WDT_BUSY 0
- #define WDT_CAN_BE_CLOSED 1
unsigned int load_val;
unsigned int timeout;
};
-/* local variables */
-static struct sp805_wdt *wdt;
static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Set to 1 to keep watchdog running after device release");
/* This routine finds load value that will reset system in required timout */
-static void wdt_setload(unsigned int timeout)
+static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout)
{
+ struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
u64 load, rate;
rate = clk_get_rate(wdt->clk);
/* roundup timeout to closest positive integer value */
wdt->timeout = div_u64((load + 1) * 2 + (rate / 2), rate);
spin_unlock(&wdt->lock);
+
+ return 0;
}
/* returns number of seconds left for reset to occur */
-static u32 wdt_timeleft(void)
+static unsigned int wdt_timeleft(struct watchdog_device *wdd)
{
+ struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
u64 load, rate;
rate = clk_get_rate(wdt->clk);
return div_u64(load, rate);
}
-/* enables watchdog timers reset */
-static void wdt_enable(void)
+static int wdt_config(struct watchdog_device *wdd, bool ping)
{
- spin_lock(&wdt->lock);
+ struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
+ int ret;
- writel_relaxed(UNLOCK, wdt->base + WDTLOCK);
- writel_relaxed(wdt->load_val, wdt->base + WDTLOAD);
- writel_relaxed(INT_MASK, wdt->base + WDTINTCLR);
- writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base + WDTCONTROL);
- writel_relaxed(LOCK, wdt->base + WDTLOCK);
+ if (!ping) {
+ ret = clk_prepare(wdt->clk);
+ if (ret) {
+ dev_err(&wdt->adev->dev, "clock prepare fail");
+ return ret;
+ }
- /* Flush posted writes. */
- readl_relaxed(wdt->base + WDTLOCK);
- spin_unlock(&wdt->lock);
-}
+ ret = clk_enable(wdt->clk);
+ if (ret) {
+ dev_err(&wdt->adev->dev, "clock enable fail");
+ clk_unprepare(wdt->clk);
+ return ret;
+ }
+ }
-/* disables watchdog timers reset */
-static void wdt_disable(void)
-{
spin_lock(&wdt->lock);
writel_relaxed(UNLOCK, wdt->base + WDTLOCK);
- writel_relaxed(0, wdt->base + WDTCONTROL);
+ writel_relaxed(wdt->load_val, wdt->base + WDTLOAD);
+
+ if (!ping) {
+ writel_relaxed(INT_MASK, wdt->base + WDTINTCLR);
+ writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base +
+ WDTCONTROL);
+ }
+
writel_relaxed(LOCK, wdt->base + WDTLOCK);
/* Flush posted writes. */
readl_relaxed(wdt->base + WDTLOCK);
spin_unlock(&wdt->lock);
+
+ return 0;
}
-static ssize_t sp805_wdt_write(struct file *file, const char *data,
- size_t len, loff_t *ppos)
+static int wdt_ping(struct watchdog_device *wdd)
{
- if (len) {
- if (!nowayout) {
- size_t i;
-
- clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);
-
- for (i = 0; i != len; i++) {
- char c;
-
- if (get_user(c, data + i))
- return -EFAULT;
- /* Check for Magic Close character */
- if (c == 'V') {
- set_bit(WDT_CAN_BE_CLOSED,
- &wdt->status);
- break;
- }
- }
- }
- wdt_enable();
- }
- return len;
+ return wdt_config(wdd, true);
}
-static const struct watchdog_info ident = {
- .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
- .identity = MODULE_NAME,
-};
-
-static long sp805_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
+/* enables watchdog timers reset */
+static int wdt_enable(struct watchdog_device *wdd)
{
- int ret = -ENOTTY;
- unsigned int timeout;
-
- 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_KEEPALIVE:
- wdt_enable();
- ret = 0;
- break;
-
- case WDIOC_SETTIMEOUT:
- ret = get_user(timeout, (unsigned int *)arg);
- if (ret)
- break;
-
- wdt_setload(timeout);
-
- wdt_enable();
- /* Fall through */
-
- case WDIOC_GETTIMEOUT:
- ret = put_user(wdt->timeout, (unsigned int *)arg);
- break;
- case WDIOC_GETTIMELEFT:
- ret = put_user(wdt_timeleft(), (unsigned int *)arg);
- break;
- }
- return ret;
+ return wdt_config(wdd, false);
}
-static int sp805_wdt_open(struct inode *inode, struct file *file)
+/* disables watchdog timers reset */
+static int wdt_disable(struct watchdog_device *wdd)
{
- int ret = 0;
-
- if (test_and_set_bit(WDT_BUSY, &wdt->status))
- return -EBUSY;
-
- ret = clk_enable(wdt->clk);
- if (ret) {
- dev_err(&wdt->adev->dev, "clock enable fail");
- goto err;
- }
-
- wdt_enable();
+ struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
- /* can not be closed, once enabled */
- clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);
- return nonseekable_open(inode, file);
+ spin_lock(&wdt->lock);
-err:
- clear_bit(WDT_BUSY, &wdt->status);
- return ret;
-}
+ writel_relaxed(UNLOCK, wdt->base + WDTLOCK);
+ writel_relaxed(0, wdt->base + WDTCONTROL);
+ writel_relaxed(LOCK, wdt->base + WDTLOCK);
-static int sp805_wdt_release(struct inode *inode, struct file *file)
-{
- if (!test_bit(WDT_CAN_BE_CLOSED, &wdt->status)) {
- clear_bit(WDT_BUSY, &wdt->status);
- dev_warn(&wdt->adev->dev, "Device closed unexpectedly\n");
- return 0;
- }
+ /* Flush posted writes. */
+ readl_relaxed(wdt->base + WDTLOCK);
+ spin_unlock(&wdt->lock);
- wdt_disable();
clk_disable(wdt->clk);
- clear_bit(WDT_BUSY, &wdt->status);
+ clk_unprepare(wdt->clk);
return 0;
}
-static const struct file_operations sp805_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = sp805_wdt_write,
- .unlocked_ioctl = sp805_wdt_ioctl,
- .open = sp805_wdt_open,
- .release = sp805_wdt_release,
+static const struct watchdog_info wdt_info = {
+ .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = MODULE_NAME,
};
-static struct miscdevice sp805_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &sp805_wdt_fops,
+static const struct watchdog_ops wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = wdt_enable,
+ .stop = wdt_disable,
+ .ping = wdt_ping,
+ .set_timeout = wdt_setload,
+ .get_timeleft = wdt_timeleft,
};
static int __devinit
sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id)
{
+ struct sp805_wdt *wdt;
int ret = 0;
if (!devm_request_mem_region(&adev->dev, adev->res.start,
}
wdt->adev = adev;
+ wdt->wdd.info = &wdt_info;
+ wdt->wdd.ops = &wdt_ops;
+
spin_lock_init(&wdt->lock);
- wdt_setload(DEFAULT_TIMEOUT);
+ watchdog_set_nowayout(&wdt->wdd, nowayout);
+ watchdog_set_drvdata(&wdt->wdd, wdt);
+ wdt_setload(&wdt->wdd, DEFAULT_TIMEOUT);
- ret = misc_register(&sp805_wdt_miscdev);
- if (ret < 0) {
- dev_warn(&adev->dev, "cannot register misc device\n");
- goto err_misc_register;
+ ret = watchdog_register_device(&wdt->wdd);
+ if (ret) {
+ dev_err(&adev->dev, "watchdog_register_device() failed: %d\n",
+ ret);
+ goto err_register;
}
+ amba_set_drvdata(adev, wdt);
dev_info(&adev->dev, "registration successful\n");
return 0;
-err_misc_register:
+err_register:
clk_put(wdt->clk);
err:
dev_err(&adev->dev, "Probe Failed!!!\n");
static int __devexit sp805_wdt_remove(struct amba_device *adev)
{
- misc_deregister(&sp805_wdt_miscdev);
+ struct sp805_wdt *wdt = amba_get_drvdata(adev);
+
+ watchdog_unregister_device(&wdt->wdd);
+ amba_set_drvdata(adev, NULL);
+ watchdog_set_drvdata(&wdt->wdd, NULL);
clk_put(wdt->clk);
return 0;
#ifdef CONFIG_PM
static int sp805_wdt_suspend(struct device *dev)
{
- if (test_bit(WDT_BUSY, &wdt->status)) {
- wdt_disable();
- clk_disable(wdt->clk);
- }
+ struct sp805_wdt *wdt = dev_get_drvdata(dev);
+
+ if (watchdog_active(&wdt->wdd))
+ return wdt_disable(&wdt->wdd);
return 0;
}
static int sp805_wdt_resume(struct device *dev)
{
- int ret = 0;
+ struct sp805_wdt *wdt = dev_get_drvdata(dev);
- if (test_bit(WDT_BUSY, &wdt->status)) {
- ret = clk_enable(wdt->clk);
- if (ret) {
- dev_err(dev, "clock enable fail");
- return ret;
- }
- wdt_enable();
- }
+ if (watchdog_active(&wdt->wdd))
+ return wdt_enable(&wdt->wdd);
- return ret;
+ return 0;
}
#endif /* CONFIG_PM */
module_amba_driver(sp805_wdt_driver);
-module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout,
- "Set to 1 to keep watchdog running after device release");
-
-MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");
+MODULE_AUTHOR("Viresh Kumar <viresh.linux@gmail.com>");
MODULE_DESCRIPTION("ARM SP805 Watchdog Driver");
MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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