[PATCH v2 8/8] watchdog: at91sam9: Convert to use infrastructure triggered keepalives
The watchdog infrastructure now supports handling watchdog keepalive
if the watchdog is running while the watchdog device is closed.
The infrastructure now also supports generating additional heartbeats
if the maximum hardware timeout is smaller than or close to the
configured timeout. Convert the driver to use this
infrastructure.
Signed-off-by: Guenter Roeck
---
v2: No changes
---
drivers/watchdog/at91sam9_wdt.c | 102 +---
1 file changed, 11 insertions(+), 91 deletions(-)
diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index e4698f7c5f93..0de39b52962c 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -29,7 +29,6 @@
#include
#include
#include
-#include
#include
#include
#include
@@ -48,8 +47,8 @@
* use this to convert a watchdog
* value from/to milliseconds.
*/
-#define ticks_to_hz_rounddown(t) t) + 1) * HZ) >> 8)
-#define ticks_to_hz_roundup(t) (t) + 1) * HZ) + 255) >> 8)
+#define ticks_to_ms_rounddown(t) t) + 1) * 1000) >> 8)
+#define ticks_to_ms_roundup(t) (t) + 1) * 1000) + 255) >> 8)
#define ticks_to_secs(t) (((t) + 1) >> 8)
#define secs_to_ticks(s) ((s) ? (((s) << 8) - 1) : 0)
@@ -64,9 +63,6 @@
/* Hardware timeout in seconds */
#define WDT_HW_TIMEOUT 2
-/* Timer heartbeat (500ms) */
-#define WDT_TIMEOUT(HZ/2)
-
/* User land timeout */
#define WDT_HEARTBEAT 15
static int heartbeat;
@@ -83,11 +79,8 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once
started "
struct at91wdt {
struct watchdog_device wdd;
void __iomem *base;
- unsigned long next_heartbeat; /* the next_heartbeat for the timer */
- struct timer_list timer;/* The timer that pings the watchdog */
u32 mr;
u32 mr_mask;
- unsigned long heartbeat;/* WDT heartbeat in jiffies */
bool nowayout;
unsigned int irq;
};
@@ -107,47 +100,13 @@ static irqreturn_t wdt_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
-/*
- * Reload the watchdog timer. (ie, pat the watchdog)
- */
-static inline void at91_wdt_reset(struct at91wdt *wdt)
-{
- wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
-}
-
-/*
- * Timer tick
- */
-static void at91_ping(unsigned long data)
-{
- struct at91wdt *wdt = (struct at91wdt *)data;
- if (time_before(jiffies, wdt->next_heartbeat) ||
- !watchdog_active(>wdd)) {
- at91_wdt_reset(wdt);
- mod_timer(>timer, jiffies + wdt->heartbeat);
- } else {
- pr_crit("I will reset your machine !\n");
- }
-}
-
static int at91_wdt_start(struct watchdog_device *wdd)
{
struct at91wdt *wdt = to_wdt(wdd);
- /* calculate when the next userspace timeout will be */
- wdt->next_heartbeat = jiffies + wdd->timeout * HZ;
- return 0;
-}
-static int at91_wdt_stop(struct watchdog_device *wdd)
-{
- /* The watchdog timer hardware can not be stopped... */
- return 0;
-}
+ wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
-static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int
new_timeout)
-{
- wdd->timeout = new_timeout;
- return at91_wdt_start(wdd);
+ return 0;
}
static int at91_wdt_init(struct platform_device *pdev, struct at91wdt *wdt)
@@ -157,8 +116,8 @@ static int at91_wdt_init(struct platform_device *pdev,
struct at91wdt *wdt)
u32 value;
int err;
u32 mask = wdt->mr_mask;
- unsigned long min_heartbeat = 1;
- unsigned long max_heartbeat;
+ unsigned int min_timeout = jiffies_to_msecs(1);
+ unsigned int hw_timeout;
struct device *dev = >dev;
tmp = wdt_read(wdt, AT91_WDT_MR);
@@ -180,31 +139,15 @@ static int at91_wdt_init(struct platform_device *pdev,
struct at91wdt *wdt)
delta = (tmp & AT91_WDT_WDD) >> 16;
if (delta < value)
- min_heartbeat = ticks_to_hz_roundup(value - delta);
+ min_timeout = ticks_to_ms_roundup(value - delta);
- max_heartbeat = ticks_to_hz_rounddown(value);
- if (!max_heartbeat) {
+ hw_timeout = ticks_to_ms_rounddown(value);
+ if (hw_timeout < min_timeout * 2) {
dev_err(dev,
"heartbeat is too small for the system to handle it
correctly\n");
return -EINVAL;
}
-
- /*
-* Try to reset the watchdog counter 4 or 2 times more often than
-* actually requested, to avoid spurious watchdog reset.
-* If this is not possible because of the min_heartbeat value, reset
-* it at the min_heartbeat period.
-*/
- if ((max_heartbeat / 4) >= min_heartbeat)
- wdt->heartbeat = max_heartbeat / 4;
- else if ((max_heartbeat / 2) >= min_heartbeat)
- wdt->heartbeat =
[PATCH v2 8/8] watchdog: at91sam9: Convert to use infrastructure triggered keepalives
The watchdog infrastructure now supports handling watchdog keepalive
if the watchdog is running while the watchdog device is closed.
The infrastructure now also supports generating additional heartbeats
if the maximum hardware timeout is smaller than or close to the
configured timeout. Convert the driver to use this
infrastructure.
Signed-off-by: Guenter Roeck li...@roeck-us.net
---
v2: No changes
---
drivers/watchdog/at91sam9_wdt.c | 102 +---
1 file changed, 11 insertions(+), 91 deletions(-)
diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index e4698f7c5f93..0de39b52962c 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -29,7 +29,6 @@
#include linux/types.h
#include linux/watchdog.h
#include linux/jiffies.h
-#include linux/timer.h
#include linux/bitops.h
#include linux/uaccess.h
#include linux/of.h
@@ -48,8 +47,8 @@
* use this to convert a watchdog
* value from/to milliseconds.
*/
-#define ticks_to_hz_rounddown(t) t) + 1) * HZ) 8)
-#define ticks_to_hz_roundup(t) (t) + 1) * HZ) + 255) 8)
+#define ticks_to_ms_rounddown(t) t) + 1) * 1000) 8)
+#define ticks_to_ms_roundup(t) (t) + 1) * 1000) + 255) 8)
#define ticks_to_secs(t) (((t) + 1) 8)
#define secs_to_ticks(s) ((s) ? (((s) 8) - 1) : 0)
@@ -64,9 +63,6 @@
/* Hardware timeout in seconds */
#define WDT_HW_TIMEOUT 2
-/* Timer heartbeat (500ms) */
-#define WDT_TIMEOUT(HZ/2)
-
/* User land timeout */
#define WDT_HEARTBEAT 15
static int heartbeat;
@@ -83,11 +79,8 @@ MODULE_PARM_DESC(nowayout, Watchdog cannot be stopped once
started
struct at91wdt {
struct watchdog_device wdd;
void __iomem *base;
- unsigned long next_heartbeat; /* the next_heartbeat for the timer */
- struct timer_list timer;/* The timer that pings the watchdog */
u32 mr;
u32 mr_mask;
- unsigned long heartbeat;/* WDT heartbeat in jiffies */
bool nowayout;
unsigned int irq;
};
@@ -107,47 +100,13 @@ static irqreturn_t wdt_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
-/*
- * Reload the watchdog timer. (ie, pat the watchdog)
- */
-static inline void at91_wdt_reset(struct at91wdt *wdt)
-{
- wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
-}
-
-/*
- * Timer tick
- */
-static void at91_ping(unsigned long data)
-{
- struct at91wdt *wdt = (struct at91wdt *)data;
- if (time_before(jiffies, wdt-next_heartbeat) ||
- !watchdog_active(wdt-wdd)) {
- at91_wdt_reset(wdt);
- mod_timer(wdt-timer, jiffies + wdt-heartbeat);
- } else {
- pr_crit(I will reset your machine !\n);
- }
-}
-
static int at91_wdt_start(struct watchdog_device *wdd)
{
struct at91wdt *wdt = to_wdt(wdd);
- /* calculate when the next userspace timeout will be */
- wdt-next_heartbeat = jiffies + wdd-timeout * HZ;
- return 0;
-}
-static int at91_wdt_stop(struct watchdog_device *wdd)
-{
- /* The watchdog timer hardware can not be stopped... */
- return 0;
-}
+ wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT);
-static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int
new_timeout)
-{
- wdd-timeout = new_timeout;
- return at91_wdt_start(wdd);
+ return 0;
}
static int at91_wdt_init(struct platform_device *pdev, struct at91wdt *wdt)
@@ -157,8 +116,8 @@ static int at91_wdt_init(struct platform_device *pdev,
struct at91wdt *wdt)
u32 value;
int err;
u32 mask = wdt-mr_mask;
- unsigned long min_heartbeat = 1;
- unsigned long max_heartbeat;
+ unsigned int min_timeout = jiffies_to_msecs(1);
+ unsigned int hw_timeout;
struct device *dev = pdev-dev;
tmp = wdt_read(wdt, AT91_WDT_MR);
@@ -180,31 +139,15 @@ static int at91_wdt_init(struct platform_device *pdev,
struct at91wdt *wdt)
delta = (tmp AT91_WDT_WDD) 16;
if (delta value)
- min_heartbeat = ticks_to_hz_roundup(value - delta);
+ min_timeout = ticks_to_ms_roundup(value - delta);
- max_heartbeat = ticks_to_hz_rounddown(value);
- if (!max_heartbeat) {
+ hw_timeout = ticks_to_ms_rounddown(value);
+ if (hw_timeout min_timeout * 2) {
dev_err(dev,
heartbeat is too small for the system to handle it
correctly\n);
return -EINVAL;
}
-
- /*
-* Try to reset the watchdog counter 4 or 2 times more often than
-* actually requested, to avoid spurious watchdog reset.
-* If this is not possible because of the min_heartbeat value, reset
-* it at the min_heartbeat period.
-*/
- if ((max_heartbeat / 4) = min_heartbeat)
- wdt-heartbeat = max_heartbeat / 4;
-
