rtc: add alarm/update irq interfaces

Add standard interfaces for alarm/update irqs enabling.  Drivers are no
more required to implement equivalent ioctl code as rtc-dev will provide
it.

UIE emulation should now be handled correctly and will work even for those
RTC drivers who cannot be configured to do both UIE and AIE.

Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 123092d..165a818 100644 (file)
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -102,9 +102,13 @@ config RTC_INTF_DEV_UIE_EMUL
        depends on RTC_INTF_DEV
        help
          Provides an emulation for RTC_UIE if the underlying rtc chip
-         driver does not expose RTC_UIE ioctls.  Those requests generate
+         driver does not expose RTC_UIE ioctls. Those requests generate
          once-per-second update interrupts, used for synchronization.
 
+         The emulation code will read the time from the hardware
+         clock several times per second, please enable this option
+         only if you know that you really need it.
+
 config RTC_DRV_TEST
        tristate "Test driver/device"
        help

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index a04c1b6..fd2c652 100644 (file)
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -307,6 +307,60 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 }
 EXPORT_SYMBOL_GPL(rtc_set_alarm);
 
+int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
+{
+       int err = mutex_lock_interruptible(&rtc->ops_lock);
+       if (err)
+               return err;
+
+       if (!rtc->ops)
+               err = -ENODEV;
+       else if (!rtc->ops->alarm_irq_enable)
+               err = -EINVAL;
+       else
+               err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
+
+       mutex_unlock(&rtc->ops_lock);
+       return err;
+}
+EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
+
+int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
+{
+       int err = mutex_lock_interruptible(&rtc->ops_lock);
+       if (err)
+               return err;
+
+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+       if (enabled == 0 && rtc->uie_irq_active) {
+               mutex_unlock(&rtc->ops_lock);
+               return rtc_dev_update_irq_enable_emul(rtc, enabled);
+       }
+#endif
+
+       if (!rtc->ops)
+               err = -ENODEV;
+       else if (!rtc->ops->update_irq_enable)
+               err = -EINVAL;
+       else
+               err = rtc->ops->update_irq_enable(rtc->dev.parent, enabled);
+
+       mutex_unlock(&rtc->ops_lock);
+
+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+       /*
+        * Enable emulation if the driver did not provide
+        * the update_irq_enable function pointer or if returned
+        * -EINVAL to signal that it has been configured without
+        * interrupts or that are not available at the moment.
+        */
+       if (err == -EINVAL)
+               err = rtc_dev_update_irq_enable_emul(rtc, enabled);
+#endif
+       return err;
+}
+EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
+
 /**
  * rtc_update_irq - report RTC periodic, alarm, and/or update irqs
  * @rtc: the rtc device

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index ecdea44..45152f4 100644 (file)
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -92,10 +92,10 @@ static void rtc_uie_timer(unsigned long data)
        spin_unlock_irqrestore(&rtc->irq_lock, flags);
 }
 
-static void clear_uie(struct rtc_device *rtc)
+static int clear_uie(struct rtc_device *rtc)
 {
        spin_lock_irq(&rtc->irq_lock);
-       if (rtc->irq_active) {
+       if (rtc->uie_irq_active) {
                rtc->stop_uie_polling = 1;
                if (rtc->uie_timer_active) {
                        spin_unlock_irq(&rtc->irq_lock);
@@ -108,9 +108,10 @@ static void clear_uie(struct rtc_device *rtc)
                        flush_scheduled_work();
                        spin_lock_irq(&rtc->irq_lock);
                }
-               rtc->irq_active = 0;
+               rtc->uie_irq_active = 0;
        }
        spin_unlock_irq(&rtc->irq_lock);
+       return 0;
 }
 
 static int set_uie(struct rtc_device *rtc)
@@ -122,8 +123,8 @@ static int set_uie(struct rtc_device *rtc)
        if (err)
                return err;
        spin_lock_irq(&rtc->irq_lock);
-       if (!rtc->irq_active) {
-               rtc->irq_active = 1;
+       if (!rtc->uie_irq_active) {
+               rtc->uie_irq_active = 1;
                rtc->stop_uie_polling = 0;
                rtc->oldsecs = tm.tm_sec;
                rtc->uie_task_active = 1;
@@ -134,6 +135,16 @@ static int set_uie(struct rtc_device *rtc)
        spin_unlock_irq(&rtc->irq_lock);
        return 0;
 }
+
+int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
+{
+       if (enabled)
+               return set_uie(rtc);
+       else
+               return clear_uie(rtc);
+}
+EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
+
 #endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
 
 static ssize_t
@@ -357,6 +368,22 @@ static long rtc_dev_ioctl(struct file *file,
                err = rtc_irq_set_state(rtc, NULL, 0);
                break;
 
+       case RTC_AIE_ON:
+               mutex_unlock(&rtc->ops_lock);
+               return rtc_alarm_irq_enable(rtc, 1);
+
+       case RTC_AIE_OFF:
+               mutex_unlock(&rtc->ops_lock);
+               return rtc_alarm_irq_enable(rtc, 0);
+
+       case RTC_UIE_ON:
+               mutex_unlock(&rtc->ops_lock);
+               return rtc_update_irq_enable(rtc, 1);
+
+       case RTC_UIE_OFF:
+               mutex_unlock(&rtc->ops_lock);
+               return rtc_update_irq_enable(rtc, 0);
+
        case RTC_IRQP_SET:
                err = rtc_irq_set_freq(rtc, NULL, arg);
                break;
@@ -401,17 +428,6 @@ static long rtc_dev_ioctl(struct file *file,
                        err = -EFAULT;
                return err;
 
-#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
-       case RTC_UIE_OFF:
-               mutex_unlock(&rtc->ops_lock);
-               clear_uie(rtc);
-               return 0;
-
-       case RTC_UIE_ON:
-               mutex_unlock(&rtc->ops_lock);
-               err = set_uie(rtc);
-               return err;
-#endif
        default:
                err = -ENOTTY;
                break;
@@ -440,7 +456,10 @@ static int rtc_dev_release(struct inode *inode, struct file *file)
         * Leave the alarm alone; it may be set to trigger a system wakeup
         * later, or be used by kernel code, and is a one-shot event anyway.
         */
+
+       /* Keep ioctl until all drivers are converted */
        rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
+       rtc_update_irq_enable(rtc, 0);
        rtc_irq_set_state(rtc, NULL, 0);
 
        if (rtc->ops->release)

diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 91f597a..4046b75 100644 (file)
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -145,6 +145,8 @@ struct rtc_class_ops {
        int (*irq_set_state)(struct device *, int enabled);
        int (*irq_set_freq)(struct device *, int freq);
        int (*read_callback)(struct device *, int data);
+       int (*alarm_irq_enable)(struct device *, unsigned int enabled);
+       int (*update_irq_enable)(struct device *, unsigned int enabled);
 };
 
 #define RTC_DEVICE_NAME_SIZE 20
@@ -181,7 +183,7 @@ struct rtc_device
        struct timer_list uie_timer;
        /* Those fields are protected by rtc->irq_lock */
        unsigned int oldsecs;
-       unsigned int irq_active:1;
+       unsigned int uie_irq_active:1;
        unsigned int stop_uie_polling:1;
        unsigned int uie_task_active:1;
        unsigned int uie_timer_active:1;
@@ -216,6 +218,10 @@ extern int rtc_irq_set_state(struct rtc_device *rtc,
                                struct rtc_task *task, int enabled);
 extern int rtc_irq_set_freq(struct rtc_device *rtc,
                                struct rtc_task *task, int freq);
+extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
+extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
+extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
+                                               unsigned int enabled);
 
 typedef struct rtc_task {
        void (*func)(void *private_data);