diff options
| -rw-r--r-- | drivers/rtc/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/rtc/rtc-dev.c | 102 | ||||
| -rw-r--r-- | include/linux/rtc.h | 10 |
3 files changed, 119 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 9e249650baf0..725d6b696792 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -73,6 +73,13 @@ 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_UIE_EMUL + bool "RTC UIE emulation on dev interface" + depends on RTC_INTF_DEV + help + Provides an emulation for RTC_UIE if the underlaying rtc chip + driver did not provide RTC_UIE ioctls. + comment "RTC drivers" depends on RTC_CLASS diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 2011567005f9..07387c99df0d 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -48,6 +48,93 @@ static int rtc_dev_open(struct inode *inode, struct file *file) return err; } +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL +/* + * 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; + int num = 0; + int err; + + err = rtc_read_time(&rtc->class_dev, &tm); + spin_lock_irq(&rtc->irq_lock); + if (rtc->stop_uie_polling || err) { + rtc->uie_task_active = 0; + } else if (rtc->oldsecs != tm.tm_sec) { + num = (tm.tm_sec + 60 - rtc->oldsecs) % 60; + rtc->oldsecs = tm.tm_sec; + rtc->uie_timer.expires = jiffies + HZ - (HZ/10); + rtc->uie_timer_active = 1; + rtc->uie_task_active = 0; + add_timer(&rtc->uie_timer); + } else if (schedule_work(&rtc->uie_task) == 0) { + rtc->uie_task_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->uie_timer_active = 0; + rtc->uie_task_active = 1; + if ((schedule_work(&rtc->uie_task) == 0)) + rtc->uie_task_active = 0; + spin_unlock_irqrestore(&rtc->irq_lock, flags); +} + +static void clear_uie(struct rtc_device *rtc) +{ + spin_lock_irq(&rtc->irq_lock); + if (rtc->irq_active) { + rtc->stop_uie_polling = 1; + if (rtc->uie_timer_active) { + spin_unlock_irq(&rtc->irq_lock); + del_timer_sync(&rtc->uie_timer); + spin_lock_irq(&rtc->irq_lock); + rtc->uie_timer_active = 0; + } + if (rtc->uie_task_active) { + spin_unlock_irq(&rtc->irq_lock); + flush_scheduled_work(); + spin_lock_irq(&rtc->irq_lock); + } + rtc->irq_active = 0; + } + spin_unlock_irq(&rtc->irq_lock); +} + +static int set_uie(struct rtc_device *rtc) +{ + struct rtc_time tm; + int err; + + err = rtc_read_time(&rtc->class_dev, &tm); + if (err) + return err; + spin_lock_irq(&rtc->irq_lock); + if (!rtc->irq_active) { + rtc->irq_active = 1; + rtc->stop_uie_polling = 0; + rtc->oldsecs = tm.tm_sec; + rtc->uie_task_active = 1; + if (schedule_work(&rtc->uie_task) == 0) + rtc->uie_task_active = 0; + } + rtc->irq_data = 0; + spin_unlock_irq(&rtc->irq_lock); + return 0; +} +#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */ static ssize_t rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -232,6 +319,14 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file, return -EFAULT; break; +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + case RTC_UIE_OFF: + clear_uie(rtc); + return 0; + + case RTC_UIE_ON: + return set_uie(rtc); +#endif default: err = -ENOTTY; break; @@ -244,6 +339,9 @@ static int rtc_dev_release(struct inode *inode, struct file *file) { struct rtc_device *rtc = to_rtc_device(file->private_data); +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + clear_uie(rtc); +#endif if (rtc->ops->release) rtc->ops->release(rtc->class_dev.dev); @@ -284,6 +382,10 @@ static int rtc_dev_add_device(struct class_device *class_dev, mutex_init(&rtc->char_lock); spin_lock_init(&rtc->irq_lock); init_waitqueue_head(&rtc->irq_queue); +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + INIT_WORK(&rtc->uie_task, rtc_uie_task, rtc); + setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc); +#endif cdev_init(&rtc->char_dev, &rtc_dev_fops); rtc->char_dev.owner = rtc->owner; diff --git a/include/linux/rtc.h b/include/linux/rtc.h index ab61cd1199f2..43310760fe73 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -155,6 +155,16 @@ struct rtc_device struct rtc_task *irq_task; spinlock_t irq_task_lock; int irq_freq; +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL + struct work_struct uie_task; + struct timer_list uie_timer; + /* Those fields are protected by rtc->irq_lock */ + unsigned int oldsecs; + unsigned int irq_active:1; + unsigned int stop_uie_polling:1; + unsigned int uie_task_active:1; + unsigned int uie_timer_active:1; +#endif }; #define to_rtc_device(d) container_of(d, struct rtc_device, class_dev) |