From 6610e0893b8bc6f59b14fed7f089c5997f035f88 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 23 Sep 2010 15:07:34 -0700 Subject: RTC: Rework RTC code to use timerqueue for events This patch reworks a large portion of the generic RTC code to in-effect virtualize the rtc interrupt code. The current RTC interface is very much a raw hardware interface. Via the proc, /dev/, or sysfs interfaces, applciations can set the hardware to trigger interrupts in one of three modes: AIE: Alarm interrupt UIE: Update interrupt (ie: once per second) PIE: Periodic interrupt (sub-second irqs) The problem with this interface is that it limits the RTC hardware so it can only be used by one application at a time. The purpose of this patch is to extend the RTC code so that we can multiplex multiple applications event needs onto a single RTC device. This is done by utilizing the timerqueue infrastructure to manage a list of events, which cause the RTC hardware to be programmed to fire an interrupt for the next event in the list. In order to preserve the functionality of the exsting proc,/dev/ and sysfs interfaces, we emulate the different interrupt modes as follows: AIE: We create a rtc_timer dedicated to AIE mode interrupts. There is only one per device, so we don't change existing interface semantics. UIE: Again, a dedicated rtc_timer, set for periodic mode, is used to emulate UIE interrupts. Again, only one per device. PIE: Since PIE mode interrupts fire faster then the RTC's clock read granularity, we emulate PIE mode interrupts using a hrtimer. Again, one per device. With this patch, the rtctest.c application in Documentation/rtc.txt passes fine on x86 hardware. However, there may very well still be bugs, so greatly I'd appreciate any feedback or testing! Signed-off-by: John Stultz LKML Reference: <1290136329-18291-4-git-send-email-john.stultz@linaro.org> Acked-by: Alessandro Zummo Reviewed-by: Thomas Gleixner CC: Alessandro Zummo CC: Thomas Gleixner CC: Richard Cochran --- include/linux/rtc.h | 43 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 14dbc83ded20..a3421abca703 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -107,12 +107,17 @@ extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year extern int rtc_valid_tm(struct rtc_time *tm); extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time); extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm); +ktime_t rtc_tm_to_ktime(struct rtc_time tm); +struct rtc_time rtc_ktime_to_tm(ktime_t kt); + #include #include #include #include #include +#include +#include extern struct class *rtc_class; @@ -151,7 +156,19 @@ struct rtc_class_ops { }; #define RTC_DEVICE_NAME_SIZE 20 -struct rtc_task; +typedef struct rtc_task { + void (*func)(void *private_data); + void *private_data; +} rtc_task_t; + + +struct rtc_timer { + struct rtc_task task; + struct timerqueue_node node; + ktime_t period; + int enabled; +}; + /* flags */ #define RTC_DEV_BUSY 0 @@ -179,6 +196,15 @@ struct rtc_device spinlock_t irq_task_lock; int irq_freq; int max_user_freq; + + struct timerqueue_head timerqueue; + struct rtc_timer aie_timer; + struct rtc_timer uie_rtctimer; + struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */ + int pie_enabled; + struct work_struct irqwork; + + #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL struct work_struct uie_task; struct timer_list uie_timer; @@ -224,15 +250,22 @@ 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); - void *private_data; -} rtc_task_t; +void rtc_aie_update_irq(void *private); +void rtc_uie_update_irq(void *private); +enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); int rtc_register(rtc_task_t *task); int rtc_unregister(rtc_task_t *task); int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg); +void rtctimer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); +void rtctimer_remove(struct rtc_device *rtc, struct rtc_timer *timer); +void rtctimer_init(struct rtc_timer *timer, void (*f)(void* p), void* data); +int rtctimer_start(struct rtc_device *rtc, struct rtc_timer* timer, + ktime_t expires, ktime_t period); +int rtctimer_cancel(struct rtc_device *rtc, struct rtc_timer* timer); +void rtctimer_do_work(struct work_struct *work); + static inline bool is_leap_year(unsigned int year) { return (!(year % 4) && (year % 100)) || !(year % 400); -- cgit v1.2.3 From 042620a018afcfba1d678062b62e463b9e43a68d Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 14 Oct 2010 16:22:33 -0700 Subject: RTC: Remove UIE emulation Since we provide UIE interrupts via a rtc_timer, the old emulation code can be removed. Signed-off-by: John Stultz LKML Reference: <1290136329-18291-5-git-send-email-john.stultz@linaro.org> Acked-by: Alessandro Zummo Reviewed-by: Thomas Gleixner CC: Alessandro Zummo CC: Thomas Gleixner CC: Richard Cochran --- drivers/rtc/rtc-dev.c | 104 -------------------------------------------------- include/linux/rtc.h | 12 ------ 2 files changed, 116 deletions(-) (limited to 'include') diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 62227cd52410..212b16edafc0 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -46,105 +46,6 @@ 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(struct work_struct *work) -{ - struct rtc_device *rtc = - container_of(work, struct rtc_device, uie_task); - struct rtc_time tm; - int num = 0; - int err; - - err = rtc_read_time(rtc, &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, 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 int clear_uie(struct rtc_device *rtc) -{ - spin_lock_irq(&rtc->irq_lock); - if (rtc->uie_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->uie_irq_active = 0; - } - spin_unlock_irq(&rtc->irq_lock); - return 0; -} - -static int set_uie(struct rtc_device *rtc) -{ - struct rtc_time tm; - int err; - - err = rtc_read_time(rtc, &tm); - if (err) - return err; - spin_lock_irq(&rtc->irq_lock); - 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; - if (schedule_work(&rtc->uie_task) == 0) - rtc->uie_task_active = 0; - } - rtc->irq_data = 0; - 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 rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -493,11 +394,6 @@ void rtc_dev_prepare(struct rtc_device *rtc) rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id); -#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL - INIT_WORK(&rtc->uie_task, rtc_uie_task); - 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 a3421abca703..44e18a2523a3 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -203,18 +203,6 @@ struct rtc_device struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */ int pie_enabled; struct work_struct irqwork; - - -#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 uie_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, dev) -- cgit v1.2.3 From 96c8f06a0fb359a9a89701a7afab6d837e466ab0 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 13 Dec 2010 22:45:48 +0100 Subject: rtc: Namespace fixup rtctimer_* is already occupied by sound/core/rtctimer.c. Instead of fiddling with that, rename the new functions to rtc_timer_* which reads nicer anyway. Signed-off-by: Thomas Gleixner Cc: John Stultz --- drivers/rtc/class.c | 6 +++--- drivers/rtc/interface.c | 42 +++++++++++++++++++++--------------------- include/linux/rtc.h | 12 ++++++------ 3 files changed, 30 insertions(+), 30 deletions(-) (limited to 'include') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 95d2b82762d6..3243832a17cd 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -155,11 +155,11 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, /* Init timerqueue */ timerqueue_init_head(&rtc->timerqueue); - INIT_WORK(&rtc->irqwork, rtctimer_do_work); + INIT_WORK(&rtc->irqwork, rtc_timer_do_work); /* Init aie timer */ - rtctimer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); + rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); /* Init uie timer */ - rtctimer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); + rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); /* Init pie timer */ hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); rtc->pie_timer.function = rtc_pie_update_irq; diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index c81c50b497b7..90384b9f6b2c 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -174,14 +174,14 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) if (err) return err; if (rtc->aie_timer.enabled) { - rtctimer_remove(rtc, &rtc->aie_timer); + rtc_timer_remove(rtc, &rtc->aie_timer); rtc->aie_timer.enabled = 0; } rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); rtc->aie_timer.period = ktime_set(0, 0); if (alarm->enabled) { rtc->aie_timer.enabled = 1; - rtctimer_enqueue(rtc, &rtc->aie_timer); + rtc_timer_enqueue(rtc, &rtc->aie_timer); } mutex_unlock(&rtc->ops_lock); return 0; @@ -197,9 +197,9 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) if (rtc->aie_timer.enabled != enabled) { if (enabled) { rtc->aie_timer.enabled = 1; - rtctimer_enqueue(rtc, &rtc->aie_timer); + rtc_timer_enqueue(rtc, &rtc->aie_timer); } else { - rtctimer_remove(rtc, &rtc->aie_timer); + rtc_timer_remove(rtc, &rtc->aie_timer); rtc->aie_timer.enabled = 0; } } @@ -236,9 +236,9 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); rtc->uie_rtctimer.period = ktime_set(1, 0); rtc->uie_rtctimer.enabled = 1; - rtctimer_enqueue(rtc, &rtc->uie_rtctimer); + rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); } else { - rtctimer_remove(rtc, &rtc->uie_rtctimer); + rtc_timer_remove(rtc, &rtc->uie_rtctimer); rtc->uie_rtctimer.enabled = 0; } @@ -481,7 +481,7 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) EXPORT_SYMBOL_GPL(rtc_irq_set_freq); /** - * rtctimer_enqueue - Adds a rtc_timer to the rtc_device timerqueue + * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue * @rtc rtc device * @timer timer being added. * @@ -490,7 +490,7 @@ EXPORT_SYMBOL_GPL(rtc_irq_set_freq); * * Must hold ops_lock for proper serialization of timerqueue */ -void rtctimer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) +void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) { timerqueue_add(&rtc->timerqueue, &timer->node); if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { @@ -505,7 +505,7 @@ void rtctimer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) } /** - * rtctimer_remove - Removes a rtc_timer from the rtc_device timerqueue + * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue * @rtc rtc device * @timer timer being removed. * @@ -514,7 +514,7 @@ void rtctimer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) * * Must hold ops_lock for proper serialization of timerqueue */ -void rtctimer_remove(struct rtc_device *rtc, struct rtc_timer *timer) +void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) { struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); timerqueue_del(&rtc->timerqueue, &timer->node); @@ -534,7 +534,7 @@ void rtctimer_remove(struct rtc_device *rtc, struct rtc_timer *timer) } /** - * rtctimer_do_work - Expires rtc timers + * rtc_timer_do_work - Expires rtc timers * @rtc rtc device * @timer timer being removed. * @@ -543,7 +543,7 @@ void rtctimer_remove(struct rtc_device *rtc, struct rtc_timer *timer) * * Serializes access to timerqueue via ops_lock mutex */ -void rtctimer_do_work(struct work_struct *work) +void rtc_timer_do_work(struct work_struct *work) { struct rtc_timer *timer; struct timerqueue_node *next; @@ -592,14 +592,14 @@ again: } -/* rtctimer_init - Initializes an rtc_timer +/* rtc_timer_init - Initializes an rtc_timer * @timer: timer to be intiialized * @f: function pointer to be called when timer fires * @data: private data passed to function pointer * * Kernel interface to initializing an rtc_timer. */ -void rtctimer_init(struct rtc_timer *timer, void (*f)(void* p), void* data) +void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data) { timerqueue_init(&timer->node); timer->enabled = 0; @@ -607,7 +607,7 @@ void rtctimer_init(struct rtc_timer *timer, void (*f)(void* p), void* data) timer->task.private_data = data; } -/* rtctimer_start - Sets an rtc_timer to fire in the future +/* rtc_timer_start - Sets an rtc_timer to fire in the future * @ rtc: rtc device to be used * @ timer: timer being set * @ expires: time at which to expire the timer @@ -615,36 +615,36 @@ void rtctimer_init(struct rtc_timer *timer, void (*f)(void* p), void* data) * * Kernel interface to set an rtc_timer */ -int rtctimer_start(struct rtc_device *rtc, struct rtc_timer* timer, +int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer, ktime_t expires, ktime_t period) { int ret = 0; mutex_lock(&rtc->ops_lock); if (timer->enabled) - rtctimer_remove(rtc, timer); + rtc_timer_remove(rtc, timer); timer->node.expires = expires; timer->period = period; timer->enabled = 1; - rtctimer_enqueue(rtc, timer); + rtc_timer_enqueue(rtc, timer); mutex_unlock(&rtc->ops_lock); return ret; } -/* rtctimer_cancel - Stops an rtc_timer +/* rtc_timer_cancel - Stops an rtc_timer * @ rtc: rtc device to be used * @ timer: timer being set * * Kernel interface to cancel an rtc_timer */ -int rtctimer_cancel(struct rtc_device *rtc, struct rtc_timer* timer) +int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer) { int ret = 0; mutex_lock(&rtc->ops_lock); if (timer->enabled) - rtctimer_remove(rtc, timer); + rtc_timer_remove(rtc, timer); timer->enabled = 0; mutex_unlock(&rtc->ops_lock); return ret; diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 44e18a2523a3..3c995b4d742c 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -246,13 +246,13 @@ int rtc_register(rtc_task_t *task); int rtc_unregister(rtc_task_t *task); int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg); -void rtctimer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); -void rtctimer_remove(struct rtc_device *rtc, struct rtc_timer *timer); -void rtctimer_init(struct rtc_timer *timer, void (*f)(void* p), void* data); -int rtctimer_start(struct rtc_device *rtc, struct rtc_timer* timer, +void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); +void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer); +void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data); +int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer, ktime_t expires, ktime_t period); -int rtctimer_cancel(struct rtc_device *rtc, struct rtc_timer* timer); -void rtctimer_do_work(struct work_struct *work); +int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer); +void rtc_timer_do_work(struct work_struct *work); static inline bool is_leap_year(unsigned int year) { -- cgit v1.2.3