Messages in this thread Patch in this message | | | Date | Sat, 29 Apr 2006 01:16:48 +0900 (JST) | Subject | [PATCH] RTC: rtc-dev UIE emulation | From | Atsushi Nemoto <> |
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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 <anemo@mba.ocn.ne.jp>
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) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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