/*
* RTC subsystem, interface functions
*
* Copyright (C) 2005 Tower Technologies
* Author: Alessandro Zummo <a.zummo@towertech.it>
*
* 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 <linux/rtc.h>
#include <linux/log2.h>
int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
{
int err;
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(rtc->dev.parent, tm);
}
mutex_unlock(&rtc->ops_lock);
return err;
}
EXPORT_SYMBOL_GPL(rtc_read_time);
int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
{
int err;
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(rtc->dev.parent, tm);
mutex_unlock(&rtc->ops_lock);
return err;
}
EXPORT_SYMBOL_GPL(rtc_set_time);
int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
{
int err;
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(rtc->dev.parent, secs);
else if (rtc->ops->read_time && rtc->ops->set_time) {
struct rtc_time new, old;
err = rtc->ops->read_time(rtc->dev.parent, &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(rtc->dev.parent,
&new);
}
}
else
err = -EINVAL;
mutex_unlock(&rtc->ops_lock);
return err;
}
EXPORT_SYMBOL_GPL(rtc_set_mmss);
int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
int err;
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(rtc->dev.parent, alarm);
}
mutex_unlock(&rtc->ops_lock);
return err;
}
EXPORT_SYMBOL_GPL(rtc_read_alarm);
int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
int err;
err = rtc_valid_tm(&alarm->time);
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_alarm)
err = -EINVAL;
else
err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
mutex_unlock(&rtc->ops_lock);
return err;
}
EXPORT_SYMBOL_GPL(rtc_set_alarm);
/**
* rtc_update_irq - report RTC periodic, alarm, and/or update irqs
* @rtc: the rtc device
* @num: how many irqs are being reported (usually one)
* @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
* Context: in_interrupt(), irqs blocked
*/
void rtc_update_irq(struct rtc_device *rtc,
unsigned long num, unsigned long events)
{
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 rtc_device *rtc_class_open(char *name)
{
struct device *dev;
struct rtc_device *rtc = NULL;
down(&rtc_class->sem);
list_for_each_entry(dev, &rtc_class->devices, node) {
if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0) {
dev = get_device(dev);
if (dev)
rtc = to_rtc_device(dev);
break;
}
}
if (rtc) {
if (!try_module_get(rtc->owner)) {
put_device(dev);
rtc = NULL;
}
}
up(&rtc_class->sem);
return rtc;
}
EXPORT_SYMBOL_GPL(rtc_class_open);
void rtc_class_close(struct rtc_device *rtc)
{
module_put(rtc->owner);
put_device(&rtc->dev);
}
EXPORT_SYMBOL_GPL(rtc_class_close);
int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
{
int retval = -EBUSY;
if (task == NULL || task->func == NULL)
return -EINVAL;
/* Cannot register while the char dev is in use */
if (!(mutex_trylock(&rtc->char_lock)))
return -EBUSY;
spin_lock_irq(&rtc->irq_task_lock);
if (rtc->irq_task == NULL) {
rtc->irq_task = task;
retval = 0;
}
spin_unlock_irq(&rtc->irq_task_lock);
mutex_unlock(&rtc->char_lock);
return retval;
}
EXPORT_SYMBOL_GPL(rtc_irq_register);
void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
{
spin_lock_irq(&rtc->irq_task_lock);
if (rtc->irq_task == task)
rtc->irq_task = NULL;
spin_unlock_irq(&rtc->irq_task_lock);
}
EXPORT_SYMBOL_GPL(rtc_irq_unregister);
/**
* rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
* @rtc: the rtc device
* @task: currently registered with rtc_irq_register()
* @enabled: true to enable periodic IRQs
* Context: any
*
* Note that rtc_irq_set_freq() should previously have been used to
* specify the desired frequency of periodic IRQ task->func() callbacks.
*/
int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
{
int err = 0;
unsigned long flags;
if (rtc->ops->irq_set_state == NULL)
return -ENXIO;
spin_lock_irqsave(&rtc->irq_task_lock, flags);
if (rtc->irq_task != NULL && task == NULL)
err = -EBUSY;
if (rtc->irq_task != task)
err = -EACCES;
spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
if (err == 0)
err = rtc->ops->irq_set_state(rtc->dev.parent, enabled);
return err;
}
EXPORT_SYMBOL_GPL(rtc_irq_set_state);
/**
* rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
* @rtc: the rtc device
* @task: currently registered with rtc_irq_register()
* @freq: positive frequency with which task->func() will be called
* Context: any
*
* Note that rtc_irq_set_state() is used to enable or disable the
* periodic IRQs.
*/
int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
{
int err = 0;
unsigned long flags;
if (rtc->ops->irq_set_freq == NULL)
return -ENXIO;
if (!is_power_of_2(freq))
return -EINVAL;
spin_lock_irqsave(&rtc->irq_task_lock, flags);
if (rtc->irq_task != NULL && task == NULL)
err = -EBUSY;
if (rtc->irq_task != task)
err = -EACCES;
spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
if (err == 0) {
err = rtc->ops->irq_set_freq(rtc->dev.parent, freq);
if (err == 0)
rtc->irq_freq = freq;
}
return err;
}
EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
