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authorGabriele Mazzotta <gabriele.mzt@gmail.com>2016-09-20 02:12:43 +0300
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2016-09-21 23:08:42 +0300
commit983bf1256edb477a376b6ce95adf36e13bc88f9a (patch)
tree87339d47fde88ccc10a8a42c25c2c3875617c8d7 /drivers/rtc
parent97ea1906b3c2201273ea6bb40c43c611c056ddb3 (diff)
downloadlinux-983bf1256edb477a376b6ce95adf36e13bc88f9a.tar.xz
rtc: cmos: Clear ACPI-driven alarms upon resume
Currently ACPI-driven alarms are not cleared when they wake the system. As consequence, expired alarms must be manually cleared to program a new alarm. Fix this by correctly handling ACPI-driven alarms. More specifically, the ACPI specification [1] provides for two alternative implementations of the RTC. Depending on the implementation, the driver either clear the alarm from the resume callback or from ACPI interrupt handler: - The platform has the RTC wakeup status fixed in hardware (ACPI_FADT_FIXED_RTC is 0). In this case the driver can determine if the RTC was the reason of the wakeup from the resume callback by reading the RTC status register. - The platform has no fixed hardware feature event bits. In this case a GPE is used to wake the system and the driver clears the alarm from its handler. [1] http://www.acpi.info/DOWNLOADS/ACPI_5_Errata%20A.pdf Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-cmos.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index fddde655cbd4..e8f3a212d09a 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -899,6 +899,9 @@ static inline int cmos_poweroff(struct device *dev)
#ifdef CONFIG_PM_SLEEP
+static void cmos_check_acpi_rtc_status(struct device *dev,
+ unsigned char *rtc_control);
+
static int cmos_resume(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
@@ -938,6 +941,9 @@ static int cmos_resume(struct device *dev)
tmp &= ~RTC_AIE;
hpet_mask_rtc_irq_bit(RTC_AIE);
} while (mask & RTC_AIE);
+
+ if (tmp & RTC_AIE)
+ cmos_check_acpi_rtc_status(dev, &tmp);
}
spin_unlock_irq(&rtc_lock);
@@ -975,6 +981,20 @@ static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
static u32 rtc_handler(void *context)
{
struct device *dev = context;
+ struct cmos_rtc *cmos = dev_get_drvdata(dev);
+ unsigned char rtc_control = 0;
+ unsigned char rtc_intr;
+
+ spin_lock_irq(&rtc_lock);
+ if (cmos_rtc.suspend_ctrl)
+ rtc_control = CMOS_READ(RTC_CONTROL);
+ if (rtc_control & RTC_AIE) {
+ cmos_rtc.suspend_ctrl &= ~RTC_AIE;
+ CMOS_WRITE(rtc_control, RTC_CONTROL);
+ rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
+ rtc_update_irq(cmos->rtc, 1, rtc_intr);
+ }
+ spin_unlock_irq(&rtc_lock);
pm_wakeup_event(dev, 0);
acpi_clear_event(ACPI_EVENT_RTC);
@@ -1041,12 +1061,39 @@ static void cmos_wake_setup(struct device *dev)
device_init_wakeup(dev, 1);
}
+static void cmos_check_acpi_rtc_status(struct device *dev,
+ unsigned char *rtc_control)
+{
+ struct cmos_rtc *cmos = dev_get_drvdata(dev);
+ acpi_event_status rtc_status;
+ acpi_status status;
+
+ if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
+ return;
+
+ status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
+ if (ACPI_FAILURE(status)) {
+ dev_err(dev, "Could not get RTC status\n");
+ } else if (rtc_status & ACPI_EVENT_FLAG_SET) {
+ unsigned char mask;
+ *rtc_control &= ~RTC_AIE;
+ CMOS_WRITE(*rtc_control, RTC_CONTROL);
+ mask = CMOS_READ(RTC_INTR_FLAGS);
+ rtc_update_irq(cmos->rtc, 1, mask);
+ }
+}
+
#else
static void cmos_wake_setup(struct device *dev)
{
}
+static void cmos_check_acpi_rtc_status(struct device *dev,
+ unsigned char *rtc_control)
+{
+}
+
#endif
#ifdef CONFIG_PNP