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rtc: at91rm9200: rework wakeup and interrupt handling

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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>
This commit is contained in:
Boris BREZILLON 2015-03-02 10:18:15 +01:00 committed by Rafael J. Wysocki
parent 603b1a2326
commit dd1f1f391d
1 changed files with 48 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

62
drivers/rtc/rtc-at91rm9200.c
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@ -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 void __iomem *at91_rtc_regs;
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 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
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 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
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 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
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 @@ static void at91_rtc_shutdown(struct platform_device *pdev)
/* 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 @@ static int at91_rtc_suspend(struct device *dev)
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;
}