Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver
with slight adjustments. This makes UIE-less chips/drivers work
better with programs doing read/poll on /dev/rtc, such as hwclock.
Signed-off-by: Atsushi Nemoto <[email protected]>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 65d090d..29ca46c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -73,6 +73,12 @@ config RTC_INTF_DEV
This driver can also be built as a module. If so, the module
will be called rtc-dev.
+config RTC_INTF_DEV_X
+ bool "Extended RTC operation"
+ depends on RTC_INTF_DEV
+ help
+ Provides an emulation for RTC_UIE.
+
comment "RTC drivers"
depends on RTC_CLASS
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index b1e3e61..0bbd181 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -48,6 +48,93 @@ static int rtc_dev_open(struct inode *in
return err;
}
+#ifdef CONFIG_RTC_INTF_DEV_X
+/*
+ * Routine to poll RTC seconds field for change as often as possible,
+ * after first RTC_UIE use timer to reduce polling
+ */
+static void rtc_uie_task(void *data)
+{
+ struct rtc_device *rtc = data;
+ struct rtc_time tm;
+ unsigned int tmp = rtc_read_time(&rtc->class_dev, &tm) ? 0 : tm.tm_sec;
+ int num = 0;
+
+ spin_lock_irq(&rtc->irq_lock);
+ if (rtc->stop_rtc_timers) {
+ rtc->stask_active = 0;
+ spin_unlock_irq(&rtc->irq_lock);
+ return;
+ }
+
+ if (rtc->oldsecs != tmp) {
+ num = (tmp + 60 - rtc->oldsecs) % 60;
+ rtc->oldsecs = tmp;
+
+ rtc->timer_task.expires = jiffies + HZ - (HZ/10);
+ rtc->ttask_active = 1;
+ rtc->stask_active = 0;
+ add_timer(&rtc->timer_task);
+ } else if (schedule_work(&rtc->uie_task) == 0)
+ rtc->stask_active = 0;
+ spin_unlock_irq(&rtc->irq_lock);
+ if (num)
+ rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF);
+}
+
+static void rtc_uie_timer(unsigned long data)
+{
+ struct rtc_device *rtc = (struct rtc_device *)data;
+ unsigned long flags;
+ spin_lock_irqsave(&rtc->irq_lock, flags);
+ rtc->ttask_active = 0;
+ rtc->stask_active = 1;
+ if ((schedule_work(&rtc->uie_task) == 0))
+ rtc->stask_active = 0;
+ spin_unlock_irqrestore(&rtc->irq_lock, flags);
+}
+
+static void clear_uie(struct rtc_device *rtc)
+{
+ spin_lock_irq(&rtc->irq_lock);
+ rtc->stop_rtc_timers = 1;
+ if (rtc->ttask_active) {
+ spin_unlock_irq(&rtc->irq_lock);
+ del_timer_sync(&rtc->timer_task);
+ spin_lock(&rtc->irq_lock);
+ rtc->ttask_active = 0;
+ }
+ while (rtc->stask_active) {
+ spin_unlock_irq(&rtc->irq_lock);
+ schedule();
+ spin_lock_irq(&rtc->irq_lock);
+ }
+ rtc->irq_active = 0;
+ spin_unlock_irq(&rtc->irq_lock);
+}
+
+static void set_uie(struct rtc_device *rtc)
+{
+ int start = 0;
+ spin_lock_irq(&rtc->irq_lock);
+ if (!rtc->irq_active)
+ start = rtc->irq_active = 1;
+ rtc->irq_data = 0;
+ spin_unlock_irq(&rtc->irq_lock);
+ if (start) {
+ struct rtc_time tm;
+ rtc->stop_rtc_timers = 0;
+ INIT_WORK(&rtc->uie_task, rtc_uie_task, rtc);
+ rtc->oldsecs = rtc_read_time(&rtc->class_dev, &tm) ?
+ 0 : tm.tm_sec;
+ setup_timer(&rtc->timer_task, rtc_uie_timer,
+ (unsigned long)rtc);
+ rtc->stask_active = 1;
+ if (schedule_work(&rtc->uie_task) == 0)
+ rtc->stask_active = 0;
+ }
+}
+#endif /* CONFIG_RTC_INTF_DEV_X */
static ssize_t
rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
@@ -227,6 +314,15 @@ static int rtc_dev_ioctl(struct inode *i
return -EFAULT;
break;
+#ifdef CONFIG_RTC_INTF_DEV_X
+ case RTC_UIE_OFF:
+ clear_uie(rtc);
+ return 0;
+
+ case RTC_UIE_ON:
+ set_uie(rtc);
+ return 0;
+#endif
default:
err = -EINVAL;
break;
@@ -239,6 +335,9 @@ static int rtc_dev_release(struct inode
{
struct rtc_device *rtc = to_rtc_device(file->private_data);
+#ifdef CONFIG_RTC_INTF_DEV_X
+ clear_uie(rtc);
+#endif
if (rtc->ops->release)
rtc->ops->release(rtc->class_dev.dev);
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index ab61cd1..29199c3 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -155,6 +155,15 @@ struct rtc_device
struct rtc_task *irq_task;
spinlock_t irq_task_lock;
int irq_freq;
+#ifdef CONFIG_RTC_INTF_DEV_X
+ struct work_struct uie_task;
+ struct timer_list timer_task;
+ unsigned int oldsecs;
+ unsigned int irq_active :1;
+ unsigned int stop_rtc_timers :1; /* don't requeue tasks */
+ unsigned int stask_active :1; /* schedule_work */
+ unsigned int ttask_active :1; /* timer_task */
+#endif
};
#define to_rtc_device(d) container_of(d, struct rtc_device, class_dev)
-
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