On 23/05/18 08:52, Scott Branden wrote:
On 18-05-22 04:24 PM, Ray Jui wrote:
Hi Guenter,
On 5/22/2018 1:54 PM, Guenter Roeck wrote:
On Tue, May 22, 2018 at 11:47:18AM -0700, Ray Jui wrote:
If the watchdog hardware is already enabled during the boot process,
when the Linux watchdog driver loads, it should reset the watchdog and
tell the watchdog framework. As a result, ping can be generated from
the watchdog framework, until the userspace watchdog daemon takes over
control
Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
---
drivers/watchdog/sp805_wdt.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/watchdog/sp805_wdt.c
b/drivers/watchdog/sp805_wdt.c
index 1484609..408ffbe 100644
--- a/drivers/watchdog/sp805_wdt.c
+++ b/drivers/watchdog/sp805_wdt.c
@@ -42,6 +42,7 @@
/* control register masks */
#define INT_ENABLE (1 << 0)
#define RESET_ENABLE (1 << 1)
+ #define ENABLE_MASK (INT_ENABLE | RESET_ENABLE)
#define WDTINTCLR 0x00C
#define WDTRIS 0x010
#define WDTMIS 0x014
@@ -74,6 +75,18 @@ module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Set to 1 to keep watchdog running after device release");
+/* returns true if wdt is running; otherwise returns false */
+static bool wdt_is_running(struct watchdog_device *wdd)
+{
+ struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ if ((readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK) ==
+ ENABLE_MASK)
+ return true;
+ else
+ return false;
return !!(readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK));
Note ENABLE_MASK contains two bits (INT_ENABLE and RESET_ENABLE);
therefore, a simple !!(expression) would not work? That is, the masked
result needs to be compared against the mask again to ensure both bits
are set, right?
Ray - your original code looks correct to me. Easier to read and less
prone to errors as shown in the attempted translation to a single
statement.
if (<boolean condition>)
return true;
else
return false;
still looks really dumb, though, and IMO is actually harder to read than
just "return <boolean condition>;" because it forces you to stop and
double-check that the logic is, in fact, only doing the obvious thing.
Robin.
p.s. No thanks for making me remember the mind-boggling horror of
briefly maintaining part of this legacy codebase... :P
$ grep -r '? true : false' --include=*.cpp . | wc -l
951
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