From 0c86edc0d4970649f39748c4ce4f2895f728468f Mon Sep 17 00:00:00 2001 From: Alessandro Zummo Date: Mon, 27 Mar 2006 01:16:37 -0800 Subject: [PATCH] RTC subsystem: class Add the basic RTC subsystem infrastructure to the kernel. rtc/class.c - registration facilities for RTC drivers rtc/interface.c - kernel/rtc interface functions rtc/hctosys.c - snippet of code that copies hw clock to sw clock at bootup, if configured to do so. Signed-off-by: Alessandro Zummo Acked-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/interface.c | 277 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 277 insertions(+) create mode 100644 drivers/rtc/interface.c (limited to 'drivers/rtc/interface.c') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c new file mode 100644 index 00000000000..56e490709b8 --- /dev/null +++ b/drivers/rtc/interface.c @@ -0,0 +1,277 @@ +/* + * RTC subsystem, interface functions + * + * Copyright (C) 2005 Tower Technologies + * Author: Alessandro Zummo + * + * based on arch/arm/common/rtctime.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include + +int rtc_read_time(struct class_device *class_dev, struct rtc_time *tm) +{ + int err; + struct rtc_device *rtc = to_rtc_device(class_dev); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + if (!rtc->ops) + err = -ENODEV; + else if (!rtc->ops->read_time) + err = -EINVAL; + else { + memset(tm, 0, sizeof(struct rtc_time)); + err = rtc->ops->read_time(class_dev->dev, tm); + } + + mutex_unlock(&rtc->ops_lock); + return err; +} +EXPORT_SYMBOL_GPL(rtc_read_time); + +int rtc_set_time(struct class_device *class_dev, struct rtc_time *tm) +{ + int err; + struct rtc_device *rtc = to_rtc_device(class_dev); + + err = rtc_valid_tm(tm); + if (err != 0) + return err; + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + if (!rtc->ops) + err = -ENODEV; + else if (!rtc->ops->set_time) + err = -EINVAL; + else + err = rtc->ops->set_time(class_dev->dev, tm); + + mutex_unlock(&rtc->ops_lock); + return err; +} +EXPORT_SYMBOL_GPL(rtc_set_time); + +int rtc_set_mmss(struct class_device *class_dev, unsigned long secs) +{ + int err; + struct rtc_device *rtc = to_rtc_device(class_dev); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + if (!rtc->ops) + err = -ENODEV; + else if (rtc->ops->set_mmss) + err = rtc->ops->set_mmss(class_dev->dev, secs); + else if (rtc->ops->read_time && rtc->ops->set_time) { + struct rtc_time new, old; + + err = rtc->ops->read_time(class_dev->dev, &old); + if (err == 0) { + rtc_time_to_tm(secs, &new); + + /* + * avoid writing when we're going to change the day of + * the month. We will retry in the next minute. This + * basically means that if the RTC must not drift + * by more than 1 minute in 11 minutes. + */ + if (!((old.tm_hour == 23 && old.tm_min == 59) || + (new.tm_hour == 23 && new.tm_min == 59))) + err = rtc->ops->set_time(class_dev->dev, &new); + } + } + else + err = -EINVAL; + + mutex_unlock(&rtc->ops_lock); + + return err; +} +EXPORT_SYMBOL_GPL(rtc_set_mmss); + +int rtc_read_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm) +{ + int err; + struct rtc_device *rtc = to_rtc_device(class_dev); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + if (rtc->ops == NULL) + err = -ENODEV; + else if (!rtc->ops->read_alarm) + err = -EINVAL; + else { + memset(alarm, 0, sizeof(struct rtc_wkalrm)); + err = rtc->ops->read_alarm(class_dev->dev, alarm); + } + + mutex_unlock(&rtc->ops_lock); + return err; +} +EXPORT_SYMBOL_GPL(rtc_read_alarm); + +int rtc_set_alarm(struct class_device *class_dev, struct rtc_wkalrm *alarm) +{ + int err; + struct rtc_device *rtc = to_rtc_device(class_dev); + + err = mutex_lock_interruptible(&rtc->ops_lock); + if (err) + return -EBUSY; + + if (!rtc->ops) + err = -ENODEV; + else if (!rtc->ops->set_alarm) + err = -EINVAL; + else + err = rtc->ops->set_alarm(class_dev->dev, alarm); + + mutex_unlock(&rtc->ops_lock); + return err; +} +EXPORT_SYMBOL_GPL(rtc_set_alarm); + +void rtc_update_irq(struct class_device *class_dev, + unsigned long num, unsigned long events) +{ + struct rtc_device *rtc = to_rtc_device(class_dev); + + spin_lock(&rtc->irq_lock); + rtc->irq_data = (rtc->irq_data + (num << 8)) | events; + spin_unlock(&rtc->irq_lock); + + spin_lock(&rtc->irq_task_lock); + if (rtc->irq_task) + rtc->irq_task->func(rtc->irq_task->private_data); + spin_unlock(&rtc->irq_task_lock); + + wake_up_interruptible(&rtc->irq_queue); + kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); +} +EXPORT_SYMBOL_GPL(rtc_update_irq); + +struct class_device *rtc_class_open(char *name) +{ + struct class_device *class_dev = NULL, + *class_dev_tmp; + + down(&rtc_class->sem); + list_for_each_entry(class_dev_tmp, &rtc_class->children, node) { + if (strncmp(class_dev_tmp->class_id, name, BUS_ID_SIZE) == 0) { + class_dev = class_dev_tmp; + break; + } + } + + if (class_dev) { + if (!try_module_get(to_rtc_device(class_dev)->owner)) + class_dev = NULL; + } + up(&rtc_class->sem); + + return class_dev; +} +EXPORT_SYMBOL_GPL(rtc_class_open); + +void rtc_class_close(struct class_device *class_dev) +{ + module_put(to_rtc_device(class_dev)->owner); +} +EXPORT_SYMBOL_GPL(rtc_class_close); + +int rtc_irq_register(struct class_device *class_dev, struct rtc_task *task) +{ + int retval = -EBUSY; + struct rtc_device *rtc = to_rtc_device(class_dev); + + if (task == NULL || task->func == NULL) + return -EINVAL; + + spin_lock(&rtc->irq_task_lock); + if (rtc->irq_task == NULL) { + rtc->irq_task = task; + retval = 0; + } + spin_unlock(&rtc->irq_task_lock); + + return retval; +} +EXPORT_SYMBOL_GPL(rtc_irq_register); + +void rtc_irq_unregister(struct class_device *class_dev, struct rtc_task *task) +{ + struct rtc_device *rtc = to_rtc_device(class_dev); + + spin_lock(&rtc->irq_task_lock); + if (rtc->irq_task == task) + rtc->irq_task = NULL; + spin_unlock(&rtc->irq_task_lock); +} +EXPORT_SYMBOL_GPL(rtc_irq_unregister); + +int rtc_irq_set_state(struct class_device *class_dev, struct rtc_task *task, int enabled) +{ + int err = 0; + unsigned long flags; + struct rtc_device *rtc = to_rtc_device(class_dev); + + spin_lock_irqsave(&rtc->irq_task_lock, flags); + if (rtc->irq_task != task) + err = -ENXIO; + spin_unlock_irqrestore(&rtc->irq_task_lock, flags); + + if (err == 0) + err = rtc->ops->irq_set_state(class_dev->dev, enabled); + + return err; +} +EXPORT_SYMBOL_GPL(rtc_irq_set_state); + +int rtc_irq_set_freq(struct class_device *class_dev, struct rtc_task *task, int freq) +{ + int err = 0, tmp = 0; + unsigned long flags; + struct rtc_device *rtc = to_rtc_device(class_dev); + + /* allowed range is 2-8192 */ + if (freq < 2 || freq > 8192) + return -EINVAL; +/* + FIXME: this does not belong here, will move where appropriate + at a later stage. It cannot hurt right now, trust me :) + if ((freq > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE))) + return -EACCES; +*/ + /* check if freq is a power of 2 */ + while (freq > (1 << tmp)) + tmp++; + + if (freq != (1 << tmp)) + return -EINVAL; + + spin_lock_irqsave(&rtc->irq_task_lock, flags); + if (rtc->irq_task != task) + err = -ENXIO; + spin_unlock_irqrestore(&rtc->irq_task_lock, flags); + + if (err == 0) { + err = rtc->ops->irq_set_freq(class_dev->dev, freq); + if (err == 0) + rtc->irq_freq = freq; + } + return err; +} -- cgit v1.2.3