rtc: at91rm9200: rework wakeup and interrupt handling
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>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index 70a5d94..b4f7744 100644
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -31,6 +31,7 @@
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/suspend.h>
#include <linux/uaccess.h>
#include "rtc-at91rm9200.h"
@@ -54,6 +55,10 @@
static int irq;
static DEFINE_SPINLOCK(at91_rtc_lock);
static u32 at91_rtc_shadow_imr;
+static bool suspended;
+static DEFINE_SPINLOCK(suspended_lock);
+static unsigned long cached_events;
+static u32 at91_rtc_imr;
static void at91_rtc_write_ier(u32 mask)
{
@@ -290,7 +295,9 @@
struct rtc_device *rtc = platform_get_drvdata(pdev);
unsigned int rtsr;
unsigned long events = 0;
+ int ret = IRQ_NONE;
+ spin_lock(&suspended_lock);
rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr();
if (rtsr) { /* this interrupt is shared! Is it ours? */
if (rtsr & AT91_RTC_ALARM)
@@ -304,14 +311,22 @@
at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */
- rtc_update_irq(rtc, 1, events);
+ if (!suspended) {
+ rtc_update_irq(rtc, 1, events);
- dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__,
- events >> 8, events & 0x000000FF);
+ dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n",
+ __func__, events >> 8, events & 0x000000FF);
+ } else {
+ cached_events |= events;
+ at91_rtc_write_idr(at91_rtc_imr);
+ pm_system_wakeup();
+ }
- return IRQ_HANDLED;
+ ret = IRQ_HANDLED;
}
- return IRQ_NONE; /* not handled */
+ spin_lock(&suspended_lock);
+
+ return ret;
}
static const struct at91_rtc_config at91rm9200_config = {
@@ -401,8 +416,8 @@
AT91_RTC_CALEV);
ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt,
- IRQF_SHARED,
- "at91_rtc", pdev);
+ IRQF_SHARED | IRQF_COND_SUSPEND,
+ "at91_rtc", pdev);
if (ret) {
dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
return ret;
@@ -454,8 +469,6 @@
/* AT91RM9200 RTC Power management control */
-static u32 at91_rtc_imr;
-
static int at91_rtc_suspend(struct device *dev)
{
/* this IRQ is shared with DBGU and other hardware which isn't
@@ -464,21 +477,42 @@
at91_rtc_imr = at91_rtc_read_imr()
& (AT91_RTC_ALARM|AT91_RTC_SECEV);
if (at91_rtc_imr) {
- if (device_may_wakeup(dev))
+ if (device_may_wakeup(dev)) {
+ unsigned long flags;
+
enable_irq_wake(irq);
- else
+
+ spin_lock_irqsave(&suspended_lock, flags);
+ suspended = true;
+ spin_unlock_irqrestore(&suspended_lock, flags);
+ } else {
at91_rtc_write_idr(at91_rtc_imr);
+ }
}
return 0;
}
static int at91_rtc_resume(struct device *dev)
{
+ struct rtc_device *rtc = dev_get_drvdata(dev);
+
if (at91_rtc_imr) {
- if (device_may_wakeup(dev))
+ if (device_may_wakeup(dev)) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&suspended_lock, flags);
+
+ if (cached_events) {
+ rtc_update_irq(rtc, 1, cached_events);
+ cached_events = 0;
+ }
+
+ suspended = false;
+ spin_unlock_irqrestore(&suspended_lock, flags);
+
disable_irq_wake(irq);
- else
- at91_rtc_write_ier(at91_rtc_imr);
+ }
+ at91_rtc_write_ier(at91_rtc_imr);
}
return 0;
}
