From: boris.brezillon@free-electrons.com (Boris Brezillon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 2/6] rtc: at91sam9: rework wakeup and interrupt handling
Date: Mon, 2 Mar 2015 10:18:14 +0100 [thread overview]
Message-ID: <1425287898-15093-3-git-send-email-boris.brezillon@free-electrons.com> (raw)
In-Reply-To: <1425287898-15093-1-git-send-email-boris.brezillon@free-electrons.com>
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(-)
diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index 2183fd2..5ccaee3 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -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;
--
1.9.1
next prev parent reply other threads:[~2015-03-02 9:18 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-02 9:18 [PATCH v2 0/6] ARM: at91: fix irq_pm_install_action WARNING Boris Brezillon
2015-03-02 9:18 ` [PATCH v2 1/6] PM / wakeup: export pm_system_wakeup symbol Boris Brezillon
2015-03-02 9:18 ` Boris Brezillon [this message]
2015-03-04 18:23 ` [PATCH v2 2/6] rtc: at91sam9: rework wakeup and interrupt handling Mark Rutland
2015-03-02 9:18 ` [PATCH v2 3/6] rtc: at91rm9200: " Boris Brezillon
2015-03-02 9:18 ` [PATCH v2 4/6] clk: at91: implement suspend/resume for the PMC irqchip Boris Brezillon
2015-03-09 22:34 ` Mike Turquette
2015-03-02 9:18 ` [PATCH v2 5/6] watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND Boris Brezillon
2015-03-02 14:10 ` Guenter Roeck
2015-03-04 18:38 ` Mark Rutland
2015-03-04 21:41 ` Rafael J. Wysocki
2015-03-05 10:57 ` Mark Rutland
2015-03-05 15:10 ` Rafael J. Wysocki
2015-03-05 16:32 ` Mark Rutland
2015-03-06 0:29 ` Rafael J. Wysocki
2015-03-06 11:06 ` Mark Rutland
2015-03-06 12:39 ` Rafael J. Wysocki
2015-03-06 13:10 ` Mark Rutland
2015-03-07 9:12 ` Peter Zijlstra
2015-03-07 9:06 ` Peter Zijlstra
2015-03-05 8:53 ` Boris Brezillon
2015-03-05 10:53 ` Mark Rutland
2015-03-05 11:17 ` Boris Brezillon
2015-03-05 11:31 ` Boris Brezillon
2015-03-05 11:53 ` Mark Rutland
2015-03-07 9:18 ` Peter Zijlstra
2015-03-07 10:20 ` Sylvain Rochet
2015-03-07 10:39 ` Pavel Machek
2015-03-07 10:59 ` Sylvain Rochet
2015-03-07 11:06 ` Alexandre Belloni
2015-03-07 11:29 ` Pavel Machek
2015-03-07 11:46 ` Sylvain Rochet
2015-03-08 1:12 ` Rafael J. Wysocki
2015-03-09 7:55 ` Alexandre Belloni
2015-03-09 14:30 ` Rafael J. Wysocki
2015-03-10 21:33 ` Alexandre Belloni
2015-03-10 22:31 ` Rafael J. Wysocki
2015-03-10 22:33 ` Alexandre Belloni
2015-03-11 1:03 ` Rafael J. Wysocki
2015-03-11 7:33 ` Boris Brezillon
2015-03-08 1:11 ` Rafael J. Wysocki
2015-03-11 8:38 ` Boris Brezillon
2015-03-11 11:17 ` Nicolas Ferre
2015-03-02 9:18 ` [PATCH v2 6/6] tty: serial: atmel: rework interrupt and wakeup handling Boris Brezillon
2015-03-03 8:56 ` [PATCH v2 0/6] ARM: at91: fix irq_pm_install_action WARNING Alexandre Belloni
2015-03-03 15:35 ` Nicolas Ferre
2015-03-04 1:43 ` Rafael J. Wysocki
2015-03-04 18:43 ` Mark Rutland
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