* S3C2410 Watchdog Timer Support
*
* Based on, softdog.c by Alan Cox,
- * (c) Copyright 1996 Alan Cox <alan@redhat.com>
+ * (c) Copyright 1996 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
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Changelog:
- * 05-Oct-2004 BJD Added semaphore init to stop crashes on open
- * Fixed tmr_count / wdt_count confusion
- * Added configurable debug
- *
- * 11-Jan-2005 BJD Fixed divide-by-2 in timeout code
- *
- * 25-Jan-2005 DA Added suspend/resume support
- * Replaced reboot notifier with .shutdown method
- *
- * 10-Mar-2005 LCVR Changed S3C2410_VA to S3C24XX_VA
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
-#include <asm/uaccess.h>
-#include <asm/io.h>
-
-#include <asm/arch/map.h>
+#include <mach/map.h>
#undef S3C_VA_WATCHDOG
#define S3C_VA_WATCHDOG (0)
-#include <asm/plat-s3c/regs-watchdog.h>
+#include <plat/regs-watchdog.h>
#define PFX "s3c2410-wdt: "
static int nowayout = WATCHDOG_NOWAYOUT;
static int tmr_margin = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME;
static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT;
-static int soft_noboot = 0;
-static int debug = 0;
+static int soft_noboot;
+static int debug;
module_param(tmr_margin, int, 0);
module_param(tmr_atboot, int, 0);
module_param(soft_noboot, int, 0);
module_param(debug, int, 0);
-MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. default=" __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
-
-MODULE_PARM_DESC(tmr_atboot, "Watchdog is started at boot time if set to 1, default=" __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
-
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
-
-MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default depends on ONLY_TESTING)");
-
+MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. default="
+ __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
+MODULE_PARM_DESC(tmr_atboot,
+ "Watchdog is started at boot time if set to 1, default="
+ __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
+ "0 to reboot (default depends on ONLY_TESTING)");
MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug, (default 0)");
-
-typedef enum close_state {
- CLOSE_STATE_NOT,
- CLOSE_STATE_ALLOW=0x4021
-} close_state_t;
-
-static DECLARE_MUTEX(open_lock);
-
+static unsigned long open_lock;
static struct device *wdt_dev; /* platform device attached to */
static struct resource *wdt_mem;
static struct resource *wdt_irq;
static struct clk *wdt_clock;
static void __iomem *wdt_base;
static unsigned int wdt_count;
-static close_state_t allow_close;
+static char expect_close;
+static DEFINE_SPINLOCK(wdt_lock);
/* watchdog control routines */
#define DBG(msg...) do { \
if (debug) \
printk(KERN_INFO msg); \
- } while(0)
+ } while (0)
/* functions */
-static int s3c2410wdt_keepalive(void)
+static void s3c2410wdt_keepalive(void)
{
+ spin_lock(&wdt_lock);
writel(wdt_count, wdt_base + S3C2410_WTCNT);
- return 0;
+ spin_unlock(&wdt_lock);
}
-static int s3c2410wdt_stop(void)
+static void __s3c2410wdt_stop(void)
{
unsigned long wtcon;
wtcon = readl(wdt_base + S3C2410_WTCON);
wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
writel(wtcon, wdt_base + S3C2410_WTCON);
+}
- return 0;
+static void s3c2410wdt_stop(void)
+{
+ spin_lock(&wdt_lock);
+ __s3c2410wdt_stop();
+ spin_unlock(&wdt_lock);
}
-static int s3c2410wdt_start(void)
+static void s3c2410wdt_start(void)
{
unsigned long wtcon;
- s3c2410wdt_stop();
+ spin_lock(&wdt_lock);
+
+ __s3c2410wdt_stop();
wtcon = readl(wdt_base + S3C2410_WTCON);
wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
writel(wdt_count, wdt_base + S3C2410_WTDAT);
writel(wdt_count, wdt_base + S3C2410_WTCNT);
writel(wtcon, wdt_base + S3C2410_WTCON);
+ spin_unlock(&wdt_lock);
+}
- return 0;
+static inline int s3c2410wdt_is_running(void)
+{
+ return readl(wdt_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
}
static int s3c2410wdt_set_heartbeat(int timeout)
{
- unsigned int freq = clk_get_rate(wdt_clock);
+ unsigned long freq = clk_get_rate(wdt_clock);
unsigned int count;
unsigned int divisor = 1;
unsigned long wtcon;
freq /= 128;
count = timeout * freq;
- DBG("%s: count=%d, timeout=%d, freq=%d\n",
+ DBG("%s: count=%d, timeout=%d, freq=%lu\n",
__func__, count, timeout, freq);
/* if the count is bigger than the watchdog register,
static int s3c2410wdt_open(struct inode *inode, struct file *file)
{
- if(down_trylock(&open_lock))
+ if (test_and_set_bit(0, &open_lock))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
- allow_close = CLOSE_STATE_NOT;
+ expect_close = 0;
/* start the timer */
s3c2410wdt_start();
* Lock it in if it's a module and we set nowayout
*/
- if (allow_close == CLOSE_STATE_ALLOW) {
+ if (expect_close == 42)
s3c2410wdt_stop();
- } else {
+ else {
dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n");
s3c2410wdt_keepalive();
}
-
- allow_close = CLOSE_STATE_NOT;
- up(&open_lock);
+ expect_close = 0;
+ clear_bit(0, &open_lock);
return 0;
}
/*
* Refresh the timer.
*/
- if(len) {
+ if (len) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
- allow_close = CLOSE_STATE_NOT;
+ expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
- allow_close = CLOSE_STATE_ALLOW;
+ expect_close = 42;
}
}
-
s3c2410wdt_keepalive();
}
return len;
}
-#define OPTIONS WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE
+#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
-static struct watchdog_info s3c2410_wdt_ident = {
+static const struct watchdog_info s3c2410_wdt_ident = {
.options = OPTIONS,
.firmware_version = 0,
.identity = "S3C2410 Watchdog",
};
-static int s3c2410wdt_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static long s3c2410wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_margin;
switch (cmd) {
- default:
- return -ENOTTY;
-
- case WDIOC_GETSUPPORT:
- return copy_to_user(argp, &s3c2410_wdt_ident,
- sizeof(s3c2410_wdt_ident)) ? -EFAULT : 0;
-
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(0, p);
-
- case WDIOC_KEEPALIVE:
- s3c2410wdt_keepalive();
- return 0;
-
- case WDIOC_SETTIMEOUT:
- if (get_user(new_margin, p))
- return -EFAULT;
-
- if (s3c2410wdt_set_heartbeat(new_margin))
- return -EINVAL;
-
- s3c2410wdt_keepalive();
- return put_user(tmr_margin, p);
-
- case WDIOC_GETTIMEOUT:
- return put_user(tmr_margin, p);
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &s3c2410_wdt_ident,
+ sizeof(s3c2410_wdt_ident)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_KEEPALIVE:
+ s3c2410wdt_keepalive();
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_margin, p))
+ return -EFAULT;
+ if (s3c2410wdt_set_heartbeat(new_margin))
+ return -EINVAL;
+ s3c2410wdt_keepalive();
+ return put_user(tmr_margin, p);
+ case WDIOC_GETTIMEOUT:
+ return put_user(tmr_margin, p);
+ default:
+ return -ENOTTY;
}
}
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = s3c2410wdt_write,
- .ioctl = s3c2410wdt_ioctl,
+ .unlocked_ioctl = s3c2410wdt_ioctl,
.open = s3c2410wdt_open,
.release = s3c2410wdt_release,
};
s3c2410wdt_keepalive();
return IRQ_HANDLED;
}
+
+
+#ifdef CONFIG_CPU_FREQ
+
+static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ int ret;
+
+ if (!s3c2410wdt_is_running())
+ goto done;
+
+ if (val == CPUFREQ_PRECHANGE) {
+ /* To ensure that over the change we don't cause the
+ * watchdog to trigger, we perform an keep-alive if
+ * the watchdog is running.
+ */
+
+ s3c2410wdt_keepalive();
+ } else if (val == CPUFREQ_POSTCHANGE) {
+ s3c2410wdt_stop();
+
+ ret = s3c2410wdt_set_heartbeat(tmr_margin);
+
+ if (ret >= 0)
+ s3c2410wdt_start();
+ else
+ goto err;
+ }
+
+done:
+ return 0;
+
+ err:
+ dev_err(wdt_dev, "cannot set new value for timeout %d\n", tmr_margin);
+ return ret;
+}
+
+static struct notifier_block s3c2410wdt_cpufreq_transition_nb = {
+ .notifier_call = s3c2410wdt_cpufreq_transition,
+};
+
+static inline int s3c2410wdt_cpufreq_register(void)
+{
+ return cpufreq_register_notifier(&s3c2410wdt_cpufreq_transition_nb,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void s3c2410wdt_cpufreq_deregister(void)
+{
+ cpufreq_unregister_notifier(&s3c2410wdt_cpufreq_transition_nb,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+#else
+static inline int s3c2410wdt_cpufreq_register(void)
+{
+ return 0;
+}
+
+static inline void s3c2410wdt_cpufreq_deregister(void)
+{
+}
+#endif
+
+
+
/* device interface */
-static int s3c2410wdt_probe(struct platform_device *pdev)
+static int __devinit s3c2410wdt_probe(struct platform_device *pdev)
{
struct resource *res;
struct device *dev;
return -ENOENT;
}
- size = (res->end-res->start)+1;
+ size = resource_size(res);
wdt_mem = request_mem_region(res->start, size, pdev->name);
if (wdt_mem == NULL) {
dev_err(dev, "failed to get memory region\n");
}
wdt_base = ioremap(res->start, size);
- if (wdt_base == 0) {
+ if (wdt_base == NULL) {
dev_err(dev, "failed to ioremap() region\n");
ret = -EINVAL;
goto err_req;
clk_enable(wdt_clock);
+ if (s3c2410wdt_cpufreq_register() < 0) {
+ printk(KERN_ERR PFX "failed to register cpufreq\n");
+ goto err_clk;
+ }
+
/* see if we can actually set the requested timer margin, and if
* not, try the default value */
if (s3c2410wdt_set_heartbeat(tmr_margin)) {
- started = s3c2410wdt_set_heartbeat(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
+ started = s3c2410wdt_set_heartbeat(
+ CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
- if (started == 0) {
- dev_info(dev,"tmr_margin value out of range, default %d used\n",
+ if (started == 0)
+ dev_info(dev,
+ "tmr_margin value out of range, default %d used\n",
CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
- } else {
- dev_info(dev, "default timer value is out of range, cannot start\n");
- }
+ else
+ dev_info(dev, "default timer value is out of range, "
+ "cannot start\n");
}
ret = misc_register(&s3c2410wdt_miscdev);
if (ret) {
dev_err(dev, "cannot register miscdev on minor=%d (%d)\n",
WATCHDOG_MINOR, ret);
- goto err_clk;
+ goto err_cpufreq;
}
if (tmr_atboot && started == 0) {
(wtcon & S3C2410_WTCON_ENABLE) ? "" : "in",
(wtcon & S3C2410_WTCON_RSTEN) ? "" : "dis",
(wtcon & S3C2410_WTCON_INTEN) ? "" : "en");
-
+
return 0;
+ err_cpufreq:
+ s3c2410wdt_cpufreq_deregister();
+
err_clk:
clk_disable(wdt_clock);
clk_put(wdt_clock);
return ret;
}
-static int s3c2410wdt_remove(struct platform_device *dev)
+static int __devexit s3c2410wdt_remove(struct platform_device *dev)
{
+ s3c2410wdt_cpufreq_deregister();
+
release_resource(wdt_mem);
kfree(wdt_mem);
wdt_mem = NULL;
static void s3c2410wdt_shutdown(struct platform_device *dev)
{
- s3c2410wdt_stop();
+ s3c2410wdt_stop();
}
#ifdef CONFIG_PM
static struct platform_driver s3c2410wdt_driver = {
.probe = s3c2410wdt_probe,
- .remove = s3c2410wdt_remove,
+ .remove = __devexit_p(s3c2410wdt_remove),
.shutdown = s3c2410wdt_shutdown,
.suspend = s3c2410wdt_suspend,
.resume = s3c2410wdt_resume,
};
-static char banner[] __initdata = KERN_INFO "S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics\n";
+static char banner[] __initdata =
+ KERN_INFO "S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics\n";
static int __init watchdog_init(void)
{
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff