"Varadarajan, Charulatha" <charu@xxxxxx> writes: > With OMAP2PLUS watchdog implemented in hwmod fw way, the > module is reset during init. Please drop this sentence, as it's not directly related to hwmod, but related to hardware reset, and was previously masked by most bootloaders. > After a watchdog timer module reset, the WDTs are enabled. The > default time for a system reset after a watchdog module reset > is ~10s as per the default value of the WDT registers. Hence > the system would be reset after 10s, if watchdog is not disabled > within 10s. > > This patch fixes the above issue by disabling the watchdog timer > after reset during initialization of devices. Should also describe what happends if/when the watchdog driver is loaded. Kevin > Signed-off-by: Charulatha V <charu@xxxxxx> > Reported-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> > --- > This patch is dependent on the below patch series (wdt hwmod) and > is created on top of pm-core branch. > http://www.spinics.net/lists/linux-omap/msg37043.html > > arch/arm/mach-omap2/devices.c | 44 +++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 44 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c > index 8e2f0aa..9f44fc6 100644 > --- a/arch/arm/mach-omap2/devices.c > +++ b/arch/arm/mach-omap2/devices.c > @@ -916,11 +916,55 @@ static inline void omap_init_vout(void) {} > > /*-------------------------------------------------------------------------*/ > > +/* > + * WDT mdoule is reset during init which enables the watchdog. > + * Hence it is required to disable the watchdog after the WDT reset > + * during init. Otherwise the system would reboot as per the default > + * watchdog timer registers settings. > + */ > +#define OMAP_WDT_WPS (0x34) > +#define OMAP_WDT_SPR (0x48) > + > +static int omap2_disable_wdt(struct omap_hwmod *oh, void *user) > +{ > + void __iomem *base; > + > + if (!oh) > + pr_err("Could not look up wdtimer_hwmod\n"); > + > + base = oh->_mpu_rt_va; > + > + /* Enable the clocks before accessing the WDT registers */ > + omap_hwmod_enable(oh); > + > + /* sequence required to disable watchdog */ > + __raw_writel(0xAAAA, base + OMAP_WDT_SPR); /* TIMER_MODE */ > + while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) > + cpu_relax(); > + > + __raw_writel(0x5555, base + OMAP_WDT_SPR); /* TIMER_MODE */ > + while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) > + cpu_relax(); > + > + omap_hwmod_idle(oh); > + > + return 0; > +} > + > +static void __init omap_disable_wdt(void) > +{ > + if (cpu_class_is_omap2()) > + omap_hwmod_for_each_by_class("wd_timer", > + omap2_disable_wdt, NULL); > + return; > +} > + > static int __init omap2_init_devices(void) > { > /* please keep these calls, and their implementations above, > * in alphabetical order so they're easier to sort through. > */ > + omap_disable_wdt(); > omap_hsmmc_reset(); > omap_init_camera(); > omap_init_mbox(); -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
