[PATCH 0/4] rtc: tps65910: cleanups and fixes for wake enable

[PATCH 0/4] rtc: tps65910: cleanups and fixes for wake enable

[Laxman Dewangan]

This patch series cleanups the suspend/resume implementation and 
enable system wake through alarm interrupt.

Laxman Dewangan (4):
  rtc: tps65910: enable/disable wake in suspend/resume
  rtc: tps65910: remove un-necessary irq stat save and restore
  rtc: tps65910: use sleep_pm_ops macro for initialising suspend/resume
    callbacks
  rtc: tps65910: set irq flag to IRQF_EARLY_RESUME during irq request

 drivers/rtc/rtc-tps65910.c |   44 ++++++++++++++++----------------------------
 1 files changed, 16 insertions(+), 28 deletions(-)

[PATCH 1/4] rtc: tps65910: enable/disable wake in suspend/resume

[Laxman Dewangan]

Making the rtc driver as wakeup capabale and leaving the wake
enable/disable decision to user space through a sysfs attribute.

In suspend, enable wake if device wakeup enabled.
In resume disable wake again.

This change is inline with the Documentation/power/devices.txt#
/sys/devices/.../power/wakeup files

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/rtc/rtc-tps65910.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
index 22eb4eb..c637fff 100644
--- a/drivers/rtc/rtc-tps65910.c
+++ b/drivers/rtc/rtc-tps65910.c
@@ -27,6 +27,7 @@
 
 struct tps65910_rtc {
 	struct rtc_device	*rtc;
+	int irq;
 	/* To store the list of enabled interrupts */
 	u32 irqstat;
 };
@@ -273,7 +274,8 @@ static int __devinit tps65910_rtc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "IRQ is not free.\n");
 		return ret;
 	}
-	device_init_wakeup(&pdev->dev, 1);
+	tps_rtc->irq = irq;
+	device_set_wakeup_capable(&pdev->dev, 1);
 
 	tps_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
 		&tps65910_rtc_ops, THIS_MODULE);
@@ -308,9 +310,13 @@ static int __devexit tps65910_rtc_remove(struct platform_device *pdev)
 static int tps65910_rtc_suspend(struct device *dev)
 {
 	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 	u8 alarm = TPS65910_RTC_INTERRUPTS_IT_ALARM;
 	int ret;
 
+	if (device_may_wakeup(dev))
+		enable_irq_wake(tps_rtc->irq);
+
 	/* Store current list of enabled interrupts*/
 	ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS,
 		&tps->rtc->irqstat);
@@ -324,6 +330,10 @@ static int tps65910_rtc_suspend(struct device *dev)
 static int tps65910_rtc_resume(struct device *dev)
 {
 	struct tps65910 *tps = dev_get_drvdata(dev->parent);
+	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(tps_rtc->irq);
 
 	/* Restore list of enabled interrupts before suspend */
 	return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS,
-- 
1.7.1.1

[PATCH 2/4] rtc: tps65910: remove un-necessary irq stat save and restore

[Laxman Dewangan]

The driver stores the interrupt enable register before going to
suspend and restore in resume. Also it enables alarm before going
to suspend.

The driver only write the Interrupt enable register for enabling ALARM
and does not enable any other bits. So it is not require to save complete
register and enable ALARM interrupt before suspend and restore in resume.

Also ALARM interrupt already enable if alarm is enabled before going to
suspend and hence it is not require to enable explictly in suspend.

Removing such above code.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/rtc/rtc-tps65910.c |   21 ++-------------------
 1 files changed, 2 insertions(+), 19 deletions(-)

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
index c637fff..728bb8b 100644
--- a/drivers/rtc/rtc-tps65910.c
+++ b/drivers/rtc/rtc-tps65910.c
@@ -28,8 +28,6 @@
 struct tps65910_rtc {
 	struct rtc_device	*rtc;
 	int irq;
-	/* To store the list of enabled interrupts */
-	u32 irqstat;
 };
 
 /* Total number of RTC registers needed to set time*/
@@ -309,35 +307,20 @@ static int __devexit tps65910_rtc_remove(struct platform_device *pdev)
 
 static int tps65910_rtc_suspend(struct device *dev)
 {
-	struct tps65910 *tps = dev_get_drvdata(dev->parent);
 	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
-	u8 alarm = TPS65910_RTC_INTERRUPTS_IT_ALARM;
-	int ret;
 
 	if (device_may_wakeup(dev))
 		enable_irq_wake(tps_rtc->irq);
-
-	/* Store current list of enabled interrupts*/
-	ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS,
-		&tps->rtc->irqstat);
-	if (ret < 0)
-		return ret;
-
-	/* Enable RTC ALARM interrupt only */
-	return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, alarm);
+	return 0;
 }
 
 static int tps65910_rtc_resume(struct device *dev)
 {
-	struct tps65910 *tps = dev_get_drvdata(dev->parent);
 	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
 
 	if (device_may_wakeup(dev))
 		disable_irq_wake(tps_rtc->irq);
-
-	/* Restore list of enabled interrupts before suspend */
-	return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS,
-		tps->rtc->irqstat);
+	return 0;
 }
 
 static const struct dev_pm_ops tps65910_rtc_pm_ops = {
-- 
1.7.1.1

[PATCH 3/4] rtc: tps65910: use sleep_pm_ops macro for initialising suspend/resume callbacks

[Laxman Dewangan]

Use SET_SYSTEM_SLEEP_PM_OPS for setting suspend/resume callbacks for
dev_pm_ops.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/rtc/rtc-tps65910.c |   13 ++++---------
 1 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
index 728bb8b..ff98e18 100644
--- a/drivers/rtc/rtc-tps65910.c
+++ b/drivers/rtc/rtc-tps65910.c
@@ -22,6 +22,7 @@
 #include <linux/rtc.h>
 #include <linux/bcd.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/tps65910.h>
 
@@ -304,7 +305,6 @@ static int __devexit tps65910_rtc_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM_SLEEP
-
 static int tps65910_rtc_suspend(struct device *dev)
 {
 	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
@@ -322,24 +322,19 @@ static int tps65910_rtc_resume(struct device *dev)
 		disable_irq_wake(tps_rtc->irq);
 	return 0;
 }
+#endif
 
 static const struct dev_pm_ops tps65910_rtc_pm_ops = {
-	.suspend	= tps65910_rtc_suspend,
-	.resume		= tps65910_rtc_resume,
+	SET_SYSTEM_SLEEP_PM_OPS(tps65910_rtc_suspend, tps65910_rtc_resume)
 };
 
-#define DEV_PM_OPS     (&tps65910_rtc_pm_ops)
-#else
-#define DEV_PM_OPS     NULL
-#endif
-
 static struct platform_driver tps65910_rtc_driver = {
 	.probe		= tps65910_rtc_probe,
 	.remove		= __devexit_p(tps65910_rtc_remove),
 	.driver		= {
 		.owner	= THIS_MODULE,
 		.name	= "tps65910-rtc",
-		.pm	= DEV_PM_OPS,
+		.pm	= &tps65910_rtc_pm_ops,
 	},
 };
 
-- 
1.7.1.1

[PATCH 4/4] rtc: tps65910: set irq flag to IRQF_EARLY_RESUME during irq request

[Laxman Dewangan]

All interrupt get disabled during system suspend and enabled during
system resume. The enabling/disabling of interrupt happen in sequence
of interrupt registration with framework.

Therefore, in resume, the parent interrupt of this device enabled before
the RTC irq interrupt enabled. If RTC is enabled for alarm wake and if
system wake by alarm then there is interrupt pending for RTC. In resume,
the parent interrupt get enabled before the rtc interrupt and hence ISR
get served. In ISR, it founds that rtc interrupt is disabled and so it does
not call the rtc isr handler and hence it misses the interrupt.

Setting flag for early resume so that rtc interrupt get enabled before
parent interrupt  and so rtc interrupt get enabled when parent interrupt
handler check for interrupt of device and call the rtc handler if it is there.
This way it will not miss the interrupt.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/rtc/rtc-tps65910.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
index ff98e18..d2e1c08 100644
--- a/drivers/rtc/rtc-tps65910.c
+++ b/drivers/rtc/rtc-tps65910.c
@@ -267,7 +267,7 @@ static int __devinit tps65910_rtc_probe(struct platform_device *pdev)
 	}
 
 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
-		tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
+		tps65910_rtc_interrupt, IRQF_TRIGGER_LOW | IRQF_EARLY_RESUME,
 		dev_name(&pdev->dev), &pdev->dev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "IRQ is not free.\n");
-- 
1.7.1.1