The IRQ line used by the RTC device is often shared with the system timer (PIT) on at91 platforms. Since timers are registering their handlers with IRQF_NO_SUSPEND, we should expect being called in suspended state, and properly wake the system up when this is the case.
Signed-off-by: Boris Brezillon <[email protected]> --- drivers/rtc/rtc-at91sam9.c | 62 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 51 insertions(+), 11 deletions(-) diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c index 2183fd2..8cf9c1b 100644 --- a/drivers/rtc/rtc-at91sam9.c +++ b/drivers/rtc/rtc-at91sam9.c @@ -77,6 +77,8 @@ struct sam9_rtc { unsigned int gpbr_offset; int irq; struct clk *sclk; + unsigned long events; + spinlock_t lock; }; #define rtt_readl(rtc, field) \ @@ -271,14 +273,9 @@ static int at91_rtc_proc(struct device *dev, struct seq_file *seq) return 0; } -/* - * IRQ handler for the RTC - */ -static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) +static irqreturn_t at91_rtc_cache_events(struct sam9_rtc *rtc) { - struct sam9_rtc *rtc = _rtc; u32 sr, mr; - unsigned long events = 0; /* Shared interrupt may be for another device. Note: reading * SR clears it, so we must only read it in this irq handler! @@ -290,18 +287,54 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) /* alarm status */ if (sr & AT91_RTT_ALMS) - events |= (RTC_AF | RTC_IRQF); + rtc->events |= (RTC_AF | RTC_IRQF); /* timer update/increment */ if (sr & AT91_RTT_RTTINC) - events |= (RTC_UF | RTC_IRQF); + rtc->events |= (RTC_UF | RTC_IRQF); + + return IRQ_HANDLED; +} + +static void at91_rtc_flush_events(struct sam9_rtc *rtc) +{ + if (!rtc->events) + return; - rtc_update_irq(rtc->rtcdev, 1, events); + rtc_update_irq(rtc->rtcdev, 1, rtc->events); + rtc->events = 0; pr_debug("%s: num=%ld, events=0x%02lx\n", __func__, - events >> 8, events & 0x000000FF); + rtc->events >> 8, rtc->events & 0x000000FF); +} - return IRQ_HANDLED; +/* + * IRQ handler for the RTC + */ +static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) +{ + struct sam9_rtc *rtc = _rtc; + int ret; + + spin_lock(&rtc->lock); + + ret = at91_rtc_cache_events(rtc); + + /* We're called in suspended state */ + if (irq_is_wakeup_armed(irq)) { + /* Mask irqs coming from this peripheral */ + rtt_writel(rtc, MR, + rtt_readl(rtc, MR) & + ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN)); + /* Trigger a system wakeup */ + irq_pm_force_wakeup(); + } else { + at91_rtc_flush_events(rtc); + } + + spin_unlock(&rtc->lock); + + return ret; } static const struct rtc_class_ops at91_rtc_ops = { @@ -499,10 +532,17 @@ static int at91_rtc_resume(struct device *dev) u32 mr; if (rtc->imr) { + unsigned long flags; + if (device_may_wakeup(dev)) disable_irq_wake(rtc->irq); mr = rtt_readl(rtc, MR); rtt_writel(rtc, MR, mr | rtc->imr); + + spin_lock_irqsave(&rtc->lock, flags); + at91_rtc_cache_events(rtc); + at91_rtc_flush_events(rtc); + spin_unlock_irqrestore(&rtc->lock, flags); } return 0; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
