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path: root/drivers/watchdog/at91rm9200_wdt.c
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Diffstat (limited to 'drivers/watchdog/at91rm9200_wdt.c')
-rw-r--r--drivers/watchdog/at91rm9200_wdt.c61
1 files changed, 54 insertions, 7 deletions
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c
index d244112d5b6f..41cecb55766c 100644
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -12,27 +12,32 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/bitops.h>
+#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/of.h>
#include <linux/of_device.h>
-#include <mach/at91_st.h>
#define WDT_DEFAULT_TIME 5 /* seconds */
#define WDT_MAX_TIME 256 /* seconds */
static int wdt_time = WDT_DEFAULT_TIME;
static bool nowayout = WATCHDOG_NOWAYOUT;
+static struct regmap *regmap_st;
module_param(wdt_time, int, 0);
MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
@@ -50,12 +55,33 @@ static unsigned long at91wdt_busy;
/* ......................................................................... */
+static int at91rm9200_restart(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ /*
+ * Perform a hardware reset with the use of the Watchdog timer.
+ */
+ regmap_write(regmap_st, AT91_ST_WDMR,
+ AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
+ regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
+
+ mdelay(2000);
+
+ pr_emerg("Unable to restart system\n");
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block at91rm9200_restart_nb = {
+ .notifier_call = at91rm9200_restart,
+ .priority = 192,
+};
+
/*
* Disable the watchdog.
*/
static inline void at91_wdt_stop(void)
{
- at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN);
+ regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN);
}
/*
@@ -63,9 +89,9 @@ static inline void at91_wdt_stop(void)
*/
static inline void at91_wdt_start(void)
{
- at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
+ regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
- at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+ regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
}
/*
@@ -73,7 +99,7 @@ static inline void at91_wdt_start(void)
*/
static inline void at91_wdt_reload(void)
{
- at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+ regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
}
/* ......................................................................... */
@@ -203,16 +229,32 @@ static struct miscdevice at91wdt_miscdev = {
static int at91wdt_probe(struct platform_device *pdev)
{
+ struct device *dev = &pdev->dev;
+ struct device *parent;
int res;
if (at91wdt_miscdev.parent)
return -EBUSY;
at91wdt_miscdev.parent = &pdev->dev;
+ parent = dev->parent;
+ if (!parent) {
+ dev_err(dev, "no parent\n");
+ return -ENODEV;
+ }
+
+ regmap_st = syscon_node_to_regmap(parent->of_node);
+ if (!regmap_st)
+ return -ENODEV;
+
res = misc_register(&at91wdt_miscdev);
if (res)
return res;
+ res = register_restart_handler(&at91rm9200_restart_nb);
+ if (res)
+ dev_warn(dev, "failed to register restart handler\n");
+
pr_info("AT91 Watchdog Timer enabled (%d seconds%s)\n",
wdt_time, nowayout ? ", nowayout" : "");
return 0;
@@ -220,8 +262,13 @@ static int at91wdt_probe(struct platform_device *pdev)
static int at91wdt_remove(struct platform_device *pdev)
{
+ struct device *dev = &pdev->dev;
int res;
+ res = unregister_restart_handler(&at91rm9200_restart_nb);
+ if (res)
+ dev_warn(dev, "failed to unregister restart handler\n");
+
res = misc_deregister(&at91wdt_miscdev);
if (!res)
at91wdt_miscdev.parent = NULL;
@@ -267,7 +314,7 @@ static struct platform_driver at91wdt_driver = {
.suspend = at91wdt_suspend,
.resume = at91wdt_resume,
.driver = {
- .name = "at91_wdt",
+ .name = "atmel_st_watchdog",
.of_match_table = at91_wdt_dt_ids,
},
};
@@ -296,4 +343,4 @@ module_exit(at91_wdt_exit);
MODULE_AUTHOR("Andrew Victor");
MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:at91_wdt");
+MODULE_ALIAS("platform:atmel_st_watchdog");