Re: [PATCH] ppc32: Added support for the Book-E style Watchdog Timer

Kumar Gala [off-list ref] wrote:

PowerPC 40x and Book-E processors support a watchdog timer at the processor
core level.  The timer has implementation dependent timeout frequencies
that can be configured by software. 

One the first Watchdog timeout we get a critical exception.  It is left
to board specific code to determine what should happen at this point.  If
nothing is done and another timeout period expires the processor may
attempt to reset the machine.

Command line parameters:
  wdt=0 : disable watchdog (default)
  wdt=1 : enable watchdog

  wdt_period=N : N sets the value of the Watchdog Timer Period.

  The Watchdog Timer Period meaning is implementation specific. Check
  User Manual for the processor for more details.

This patch is based off of work done by Takeharu Kato.

...

+#ifdef CONFIG_BOOKE_WDT
+/* Checks wdt=x and wdt_period=xx command-line option */
+int __init early_parse_wdt(char *p)
+{
+	extern u32 wdt_enable;
+
+	if (p && strncmp(p, "0", 1) != 0)
+	       wdt_enable = 1;
+
+	return 0;
+}
+early_param("wdt", early_parse_wdt);
+
+int __init early_parse_wdt_period (char *p)
+{
+	extern u32 wdt_period;
+
+	if (p)
+		wdt_period = simple_strtoul(p, NULL, 0);
+
+	return 0;
+}

Would prefer to see the declaration of wdt_period in a header file, please.

But beware that wdt_enable() is already a static symbol in a couple of
watchdog drivers.  It might be best to rename the ppc global to something
less generic-sounding while you're there.