@@ -23,6 +23,7 @@
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
+#include <linux/suspend.h>
#include <linux/clk.h>
/*
@@ -77,6 +78,9 @@ struct sam9_rtc {
unsigned int gpbr_offset;
int irq;
struct clk *sclk;
+ bool suspended;
+ unsigned long events;
+ spinlock_t lock;
};
#define rtt_readl(rtc, field) \
@@ -271,14 +275,9 @@ 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 +289,54 @@ 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 (rtc->suspended) {
+ /* Mask irqs coming from this peripheral */
+ rtt_writel(rtc, MR,
+ rtt_readl(rtc, MR) &
+ ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
+ /* Trigger a system wakeup */
+ pm_system_wakeup();
+ } else {
+ at91_rtc_flush_events(rtc);
+ }
+
+ spin_unlock(&rtc->lock);
+
+ return ret;
}
static const struct rtc_class_ops at91_rtc_ops = {
@@ -421,7 +456,8 @@ static int at91_rtc_probe(struct platform_device *pdev)
/* register irq handler after we know what name we'll use */
ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt,
- IRQF_SHARED, dev_name(&rtc->rtcdev->dev), rtc);
+ IRQF_SHARED | IRQF_COND_SUSPEND,
+ dev_name(&rtc->rtcdev->dev), rtc);
if (ret) {
dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
return ret;
@@ -482,7 +518,12 @@ static int at91_rtc_suspend(struct device *dev)
rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
if (rtc->imr) {
if (device_may_wakeup(dev) && (mr & AT91_RTT_ALMIEN)) {
+ unsigned long flags;
+
enable_irq_wake(rtc->irq);
+ spin_lock_irqsave(&rtc->lock, flags);
+ rtc->suspended = true;
+ spin_unlock_irqrestore(&rtc->lock, flags);
/* don't let RTTINC cause wakeups */
if (mr & AT91_RTT_RTTINCIEN)
rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN);
@@ -499,10 +540,18 @@ 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);
+ rtc->suspended = false;
+ at91_rtc_cache_events(rtc);
+ at91_rtc_flush_events(rtc);
+ spin_unlock_irqrestore(&rtc->lock, flags);
}
return 0;
The IRQ line used by the RTC device is usually 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. Set IRQF_COND_SUSPEND flag when registering the IRQ handler to inform irq core that it can safely be called while the system is suspended. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> --- drivers/rtc/rtc-at91sam9.c | 73 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 12 deletions(-)