From ac54cd2bd5b4db4f1c03392d63daf355627ea180 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 2 Feb 2011 16:55:19 -0800 Subject: RTC: Fix rtc driver ioctl specific shortcutting Some RTC drivers enable functionality directly via their ioctl method instead of using the generic ioctl handling code. With the recent virtualization of the RTC layer, its now important that the generic layer always be used. This patch moved the rtc driver ioctl method call to after the generic ioctl processing is done. This allows hardware specific features or ioctls to still function, while relying on the generic code for handling everything else. This patch on its own may more obviously break rtc drivers that implement the alarm irq enablement via their ioctl method instead of implementing the alarm_irq_eanble method. Those drivers will be fixed in a following patch. Additionaly, those drivers are already likely to not be functioning reliably without this patch. CC: Alessandro Zummo CC: Marcelo Roberto Jimenez CC: Thomas Gleixner Reported-by: Marcelo Roberto Jimenez Tested-by: Marcelo Roberto Jimenez Signed-off-by: John Stultz --- drivers/rtc/rtc-dev.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) (limited to 'drivers/rtc/rtc-dev.c') diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index 212b16edafc0..37c3cc1b3dd5 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -154,19 +154,7 @@ static long rtc_dev_ioctl(struct file *file, if (err) goto done; - /* try the driver's ioctl interface */ - if (ops->ioctl) { - err = ops->ioctl(rtc->dev.parent, cmd, arg); - if (err != -ENOIOCTLCMD) { - mutex_unlock(&rtc->ops_lock); - return err; - } - } - - /* if the driver does not provide the ioctl interface - * or if that particular ioctl was not implemented - * (-ENOIOCTLCMD), we will try to emulate here. - * + /* * Drivers *SHOULD NOT* provide ioctl implementations * for these requests. Instead, provide methods to * support the following code, so that the RTC's main @@ -329,7 +317,12 @@ static long rtc_dev_ioctl(struct file *file, return err; default: - err = -ENOTTY; + /* Finally try the driver's ioctl interface */ + if (ops->ioctl) { + err = ops->ioctl(rtc->dev.parent, cmd, arg); + if (err == -ENOIOCTLCMD) + err = -ENOTTY; + } break; } -- cgit v1.2.3 From 6e57b1d6a8d8ed1998229b71c102be1997e397c6 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 11 Feb 2011 17:45:40 -0800 Subject: RTC: Revert UIE emulation removal MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Uwe pointed out that my alarm based UIE emulation is not sufficient to replace the older timer/polling based UIE emulation on devices where there is no alarm irq. This causes rtc devices without alarms to return -EINVAL to UIE ioctls. The fix is to re-instate the old timer/polling method for devices without alarm irqs. This patch reverts the following commits: 042620a018afcfba1d678062b62e46 - Remove UIE emulation 1daeddd5962acad1bea55e524fc0fa - Cleanup removed UIE emulation declaration b5cc8ca1c9c3a37eaddf709b2fd3e1 - Remove Kconfig symbol for UIE emulation The emulation mode will still need to be wired-in with a following patch before it will work. CC: Uwe Kleine-König CC: Thomas Gleixner Reported-by: Uwe Kleine-König Signed-off-by: John Stultz --- drivers/rtc/Kconfig | 12 ++++++ drivers/rtc/rtc-dev.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/rtc.h | 14 +++++++ 3 files changed, 130 insertions(+) (limited to 'drivers/rtc/rtc-dev.c') diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index cdd97192dc69..4941cade319f 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -97,6 +97,18 @@ config RTC_INTF_DEV If unsure, say Y. +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 underlying rtc chip + 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/rtc-dev.c b/drivers/rtc/rtc-dev.c index 37c3cc1b3dd5..dfa72c9c2687 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -46,6 +46,105 @@ 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) @@ -387,6 +486,11 @@ 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 a0b639f8e805..80408e711bed 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -203,6 +203,18 @@ 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) @@ -235,6 +247,8 @@ 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); void rtc_aie_update_irq(void *private); void rtc_uie_update_irq(void *private); -- cgit v1.2.3 From 456d66ecd09e3bc326b93174745faafb6ac378d6 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 11 Feb 2011 18:15:23 -0800 Subject: RTC: Re-enable UIE timer/polling emulation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch re-enables UIE timer/polling emulation for rtc devices that do not support alarm irqs. CC: Uwe Kleine-König CC: Thomas Gleixner Reported-by: Uwe Kleine-König Tested-by: Uwe Kleine-König Signed-off-by: John Stultz --- drivers/rtc/interface.c | 18 +++++++++++++++++- drivers/rtc/rtc-dev.c | 2 +- include/linux/rtc.h | 1 + 3 files changed, 19 insertions(+), 2 deletions(-) (limited to 'drivers/rtc/rtc-dev.c') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 413ae0537915..cb2f0728fd70 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -228,6 +228,12 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 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, 0); + } +#endif /* make sure we're changing state */ if (rtc->uie_rtctimer.enabled == enabled) goto out; @@ -247,6 +253,16 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) out: 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; } @@ -262,7 +278,7 @@ EXPORT_SYMBOL_GPL(rtc_update_irq_enable); * * Triggers the registered irq_task function callback. */ -static void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) +void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) { unsigned long flags; diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c index dfa72c9c2687..d0e06edb14c5 100644 --- a/drivers/rtc/rtc-dev.c +++ b/drivers/rtc/rtc-dev.c @@ -76,7 +76,7 @@ static void rtc_uie_task(struct work_struct *work) } spin_unlock_irq(&rtc->irq_lock); if (num) - rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF); + rtc_handle_legacy_irq(rtc, num, RTC_UF); } static void rtc_uie_timer(unsigned long data) { diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 80408e711bed..89c3e5182991 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -250,6 +250,7 @@ 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); +void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode); void rtc_aie_update_irq(void *private); void rtc_uie_update_irq(void *private); enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); -- cgit v1.2.3