[PATCH V3 02/14] watchdog/mpcore_wdt: convert to watchdog core
Viresh Kumar
viresh.kumar at linaro.org
Tue Jun 18 11:20:26 EDT 2013
This patch converts existing mpcore watchdog driver to use already in place
common infrastructure present in watchdog core. With this lot of code goes away.
Signed-off-by: Viresh Kumar <viresh.kumar at linaro.org>
---
drivers/watchdog/Kconfig | 1 +
drivers/watchdog/mpcore_wdt.c | 275 ++++++++++--------------------------------
2 files changed, 68 insertions(+), 208 deletions(-)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c7dabe9..81bc1d4 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -224,6 +224,7 @@ config DW_WATCHDOG
config MPCORE_WATCHDOG
tristate "MPcore watchdog"
depends on HAVE_ARM_TWD && BROKEN
+ select WATCHDOG_CORE
help
Watchdog timer embedded into the MPcore system.
diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c
index 4f5ac40..bdbe3d8 100644
--- a/drivers/watchdog/mpcore_wdt.c
+++ b/drivers/watchdog/mpcore_wdt.c
@@ -25,31 +25,27 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
-#include <linux/miscdevice.h>
#include <linux/watchdog.h>
-#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
-#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <asm/smp_twd.h>
struct mpcore_wdt {
- unsigned long timer_alive;
+ struct watchdog_device wdd;
struct device *dev;
void __iomem *base;
+ spinlock_t lock;
int irq;
unsigned int perturb;
- char expect_close;
};
-static struct platform_device *mpcore_wdt_pdev;
-static DEFINE_SPINLOCK(wdt_lock);
-
+#define MIN_TIME 0x0001
+#define MAX_TIME 0xFFFF
#define TIMER_MARGIN 60
static int mpcore_margin = TIMER_MARGIN;
module_param(mpcore_margin, int, 0);
@@ -89,17 +85,18 @@ static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
}
/*
- * mpcore_wdt_keepalive - reload the timer
+ * mpcore_wdt_ping - reload the timer
*
* Note that the spec says a DIFFERENT value must be written to the reload
* register each time. The "perturb" variable deals with this by adding 1
* to the count every other time the function is called.
*/
-static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
+static int mpcore_wdt_ping(struct watchdog_device *wdd)
{
+ struct mpcore_wdt *wdt = watchdog_get_drvdata(wdd);
unsigned long count;
- spin_lock(&wdt_lock);
+ spin_lock(&wdt->lock);
/* Assume prescale is set to 256 */
count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
count = (0xFFFFFFFFU - count) * (HZ / 5);
@@ -108,24 +105,32 @@ static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
/* Reload the counter */
writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
wdt->perturb = wdt->perturb ? 0 : 1;
- spin_unlock(&wdt_lock);
+ spin_unlock(&wdt->lock);
+
+ return 0;
}
-static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
+static int mpcore_wdt_stop(struct watchdog_device *wdd)
{
- spin_lock(&wdt_lock);
+ struct mpcore_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ spin_lock(&wdt->lock);
writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
writel(0x0, wdt->base + TWD_WDOG_CONTROL);
- spin_unlock(&wdt_lock);
+ spin_unlock(&wdt->lock);
+
+ return 0;
}
-static void mpcore_wdt_start(struct mpcore_wdt *wdt)
+static int mpcore_wdt_start(struct watchdog_device *wdd)
{
+ struct mpcore_wdt *wdt = watchdog_get_drvdata(wdd);
+
dev_info(wdt->dev, "enabling watchdog\n");
/* This loads the count register but does NOT start the count yet */
- mpcore_wdt_keepalive(wdt);
+ mpcore_wdt_ping(wdd);
if (mpcore_noboot) {
/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
@@ -134,167 +139,30 @@ static void mpcore_wdt_start(struct mpcore_wdt *wdt)
/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
}
-}
-
-static int mpcore_wdt_set_heartbeat(int t)
-{
- if (t < 0x0001 || t > 0xFFFF)
- return -EINVAL;
- mpcore_margin = t;
return 0;
}
-/*
- * /dev/watchdog handling
- */
-static int mpcore_wdt_open(struct inode *inode, struct file *file)
-{
- struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev);
-
- if (test_and_set_bit(0, &wdt->timer_alive))
- return -EBUSY;
-
- if (nowayout)
- __module_get(THIS_MODULE);
-
- file->private_data = wdt;
-
- /*
- * Activate timer
- */
- mpcore_wdt_start(wdt);
-
- return nonseekable_open(inode, file);
-}
-
-static int mpcore_wdt_release(struct inode *inode, struct file *file)
+static int mpcore_wdt_set_heartbeat(struct watchdog_device *wdd, unsigned int t)
{
- struct mpcore_wdt *wdt = file->private_data;
-
- /*
- * Shut off the timer.
- * Lock it in if it's a module and we set nowayout
- */
- if (wdt->expect_close == 42)
- mpcore_wdt_stop(wdt);
- else {
- dev_crit(wdt->dev,
- "unexpected close, not stopping watchdog!\n");
- mpcore_wdt_keepalive(wdt);
- }
- clear_bit(0, &wdt->timer_alive);
- wdt->expect_close = 0;
+ mpcore_margin = t;
return 0;
}
-static ssize_t mpcore_wdt_write(struct file *file, const char *data,
- size_t len, loff_t *ppos)
-{
- struct mpcore_wdt *wdt = file->private_data;
-
- /*
- * Refresh the timer.
- */
- if (len) {
- if (!nowayout) {
- size_t i;
-
- /* In case it was set long ago */
- wdt->expect_close = 0;
-
- for (i = 0; i != len; i++) {
- char c;
-
- if (get_user(c, data + i))
- return -EFAULT;
- if (c == 'V')
- wdt->expect_close = 42;
- }
- }
- mpcore_wdt_keepalive(wdt);
- }
- return len;
-}
-
-static const struct watchdog_info ident = {
+static const struct watchdog_info mpcore_wdt_info = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "MPcore Watchdog",
};
-static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- struct mpcore_wdt *wdt = file->private_data;
- int ret;
- union {
- struct watchdog_info ident;
- int i;
- } uarg;
-
- if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
- return -ENOTTY;
-
- if (_IOC_DIR(cmd) & _IOC_WRITE) {
- ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
- if (ret)
- return -EFAULT;
- }
-
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- uarg.ident = ident;
- ret = 0;
- break;
-
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- uarg.i = 0;
- ret = 0;
- break;
-
- case WDIOC_SETOPTIONS:
- ret = -EINVAL;
- if (uarg.i & WDIOS_DISABLECARD) {
- mpcore_wdt_stop(wdt);
- ret = 0;
- }
- if (uarg.i & WDIOS_ENABLECARD) {
- mpcore_wdt_start(wdt);
- ret = 0;
- }
- break;
-
- case WDIOC_KEEPALIVE:
- mpcore_wdt_keepalive(wdt);
- ret = 0;
- break;
-
- case WDIOC_SETTIMEOUT:
- ret = mpcore_wdt_set_heartbeat(uarg.i);
- if (ret)
- break;
-
- mpcore_wdt_keepalive(wdt);
- /* Fall */
- case WDIOC_GETTIMEOUT:
- uarg.i = mpcore_margin;
- ret = 0;
- break;
-
- default:
- return -ENOTTY;
- }
-
- if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
- ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
- if (ret)
- ret = -EFAULT;
- }
- return ret;
-}
+static const struct watchdog_ops mpcore_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = mpcore_wdt_start,
+ .stop = mpcore_wdt_stop,
+ .ping = mpcore_wdt_ping,
+ .set_timeout = mpcore_wdt_set_heartbeat,
+};
/*
* System shutdown handler. Turn off the watchdog if we're
@@ -305,37 +173,15 @@ static void mpcore_wdt_shutdown(struct platform_device *pdev)
struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
- mpcore_wdt_stop(wdt);
+ mpcore_wdt_stop(&wdt->wdd);
}
-/*
- * Kernel Interfaces
- */
-static const struct file_operations mpcore_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .write = mpcore_wdt_write,
- .unlocked_ioctl = mpcore_wdt_ioctl,
- .open = mpcore_wdt_open,
- .release = mpcore_wdt_release,
-};
-
-static struct miscdevice mpcore_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &mpcore_wdt_fops,
-};
-
static int mpcore_wdt_probe(struct platform_device *pdev)
{
struct mpcore_wdt *wdt;
struct resource *res;
int ret;
- /* We only accept one device, and it must have an id of -1 */
- if (pdev->id != -1)
- return -ENODEV;
-
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
@@ -361,28 +207,39 @@ static int mpcore_wdt_probe(struct platform_device *pdev)
if (!wdt->base)
return -ENOMEM;
- mpcore_wdt_miscdev.parent = &pdev->dev;
- ret = misc_register(&mpcore_wdt_miscdev);
- if (ret) {
- dev_err(wdt->dev,
- "cannot register miscdev on minor=%d (err=%d)\n",
- WATCHDOG_MINOR, ret);
- return ret;
- }
+ wdt->wdd.info = &mpcore_wdt_info;
+ wdt->wdd.ops = &mpcore_wdt_ops;
+ wdt->wdd.min_timeout = MIN_TIME;
+ wdt->wdd.max_timeout = MAX_TIME;
+ spin_lock_init(&wdt->lock);
- mpcore_wdt_stop(wdt);
+ watchdog_set_nowayout(&wdt->wdd, nowayout);
platform_set_drvdata(pdev, wdt);
- mpcore_wdt_pdev = pdev;
+ watchdog_set_drvdata(&wdt->wdd, wdt);
+
+ mpcore_wdt_stop(&wdt->wdd);
+
+ ret = watchdog_register_device(&wdt->wdd);
+ if (ret) {
+ dev_err(wdt->dev, "watchdog_register_device() failed: %d\n",
+ ret);
+ goto err_register;
+ }
return 0;
+
+err_register:
+ watchdog_set_drvdata(&wdt->wdd, NULL);
+
+ return ret;
}
static int mpcore_wdt_remove(struct platform_device *pdev)
{
- misc_deregister(&mpcore_wdt_miscdev);
-
- mpcore_wdt_pdev = NULL;
+ struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
+ watchdog_unregister_device(&wdt->wdd);
+ watchdog_set_drvdata(&wdt->wdd, NULL);
return 0;
}
@@ -390,16 +247,18 @@ static int mpcore_wdt_remove(struct platform_device *pdev)
static int mpcore_wdt_suspend(struct platform_device *pdev, pm_message_t msg)
{
struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
- mpcore_wdt_stop(wdt); /* Turn the WDT off */
+ mpcore_wdt_stop(&wdt->wdd); /* Turn the WDT off */
+
return 0;
}
static int mpcore_wdt_resume(struct platform_device *pdev)
{
struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
- /* re-activate timer */
- if (test_bit(0, &wdt->timer_alive))
- mpcore_wdt_start(wdt);
+
+ if (watchdog_active(&wdt->wdd))
+ mpcore_wdt_start(&wdt->wdd);
+
return 0;
}
#else
@@ -425,15 +284,16 @@ static struct platform_driver mpcore_wdt_driver = {
static int __init mpcore_wdt_init(void)
{
/*
- * Check that the margin value is within it's range;
+ * Check that the mpcore_margin value is within it's range;
* if not reset to the default
*/
- if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
- mpcore_wdt_set_heartbeat(TIMER_MARGIN);
+ if (mpcore_margin < MIN_TIME || mpcore_margin > MAX_TIME) {
+ mpcore_margin = TIMER_MARGIN;
pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
TIMER_MARGIN);
}
+ mpcore_wdt_set_heartbeat(NULL, mpcore_margin);
pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
mpcore_noboot, mpcore_margin, nowayout);
@@ -451,4 +311,3 @@ module_exit(mpcore_wdt_exit);
MODULE_AUTHOR("ARM Limited");
MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
--
1.7.12.rc2.18.g61b472e
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