mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-28 11:49:32 +00:00
![Dave Young](/assets/img/avatar_default.png)
Convert to use the class iteration api. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
390 lines
9.5 KiB
C
390 lines
9.5 KiB
C
/*
|
|
* 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);
|
|
|
|
static int rtc_read_alarm_internal(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;
|
|
}
|
|
|
|
int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
|
|
{
|
|
int err;
|
|
struct rtc_time before, now;
|
|
int first_time = 1;
|
|
|
|
/* The lower level RTC driver may not be capable of filling
|
|
* in all fields of the rtc_time struct (eg. rtc-cmos),
|
|
* and so might instead return -1 in some fields.
|
|
* We deal with that here by grabbing a current RTC timestamp
|
|
* and using values from that for any missing (-1) values.
|
|
*
|
|
* But this can be racey, because some fields of the RTC timestamp
|
|
* may have wrapped in the interval since we read the RTC alarm,
|
|
* which would lead to us inserting inconsistent values in place
|
|
* of the -1 fields.
|
|
*
|
|
* Reading the alarm and timestamp in the reverse sequence
|
|
* would have the same race condition, and not solve the issue.
|
|
*
|
|
* So, we must first read the RTC timestamp,
|
|
* then read the RTC alarm value,
|
|
* and then read a second RTC timestamp.
|
|
*
|
|
* If any fields of the second timestamp have changed
|
|
* when compared with the first timestamp, then we know
|
|
* our timestamp may be inconsistent with that used by
|
|
* the low-level rtc_read_alarm_internal() function.
|
|
*
|
|
* So, when the two timestamps disagree, we just loop and do
|
|
* the process again to get a fully consistent set of values.
|
|
*
|
|
* This could all instead be done in the lower level driver,
|
|
* but since more than one lower level RTC implementation needs it,
|
|
* then it's probably best best to do it here instead of there..
|
|
*/
|
|
|
|
/* Get the "before" timestamp */
|
|
err = rtc_read_time(rtc, &before);
|
|
if (err < 0)
|
|
return err;
|
|
do {
|
|
if (!first_time)
|
|
memcpy(&before, &now, sizeof(struct rtc_time));
|
|
first_time = 0;
|
|
|
|
/* get the RTC alarm values, which may be incomplete */
|
|
err = rtc_read_alarm_internal(rtc, alarm);
|
|
if (err)
|
|
return err;
|
|
if (!alarm->enabled)
|
|
return 0;
|
|
|
|
/* get the "after" timestamp, to detect wrapped fields */
|
|
err = rtc_read_time(rtc, &now);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
/* note that tm_sec is a "don't care" value here: */
|
|
} while ( before.tm_min != now.tm_min
|
|
|| before.tm_hour != now.tm_hour
|
|
|| before.tm_mon != now.tm_mon
|
|
|| before.tm_year != now.tm_year
|
|
|| before.tm_isdst != now.tm_isdst);
|
|
|
|
/* Fill in any missing alarm fields using the timestamp */
|
|
if (alarm->time.tm_sec == -1)
|
|
alarm->time.tm_sec = now.tm_sec;
|
|
if (alarm->time.tm_min == -1)
|
|
alarm->time.tm_min = now.tm_min;
|
|
if (alarm->time.tm_hour == -1)
|
|
alarm->time.tm_hour = now.tm_hour;
|
|
if (alarm->time.tm_mday == -1)
|
|
alarm->time.tm_mday = now.tm_mday;
|
|
if (alarm->time.tm_mon == -1)
|
|
alarm->time.tm_mon = now.tm_mon;
|
|
if (alarm->time.tm_year == -1)
|
|
alarm->time.tm_year = now.tm_year;
|
|
return 0;
|
|
}
|
|
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);
|
|
|
|
static int __rtc_match(struct device *dev, void *data)
|
|
{
|
|
char *name = (char *)data;
|
|
|
|
if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
struct rtc_device *rtc_class_open(char *name)
|
|
{
|
|
struct device *dev;
|
|
struct rtc_device *rtc = NULL;
|
|
|
|
dev = class_find_device(rtc_class, name, __rtc_match);
|
|
if (dev)
|
|
rtc = to_rtc_device(dev);
|
|
|
|
if (rtc) {
|
|
if (!try_module_get(rtc->owner)) {
|
|
put_device(dev);
|
|
rtc = NULL;
|
|
}
|
|
}
|
|
|
|
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 (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
|
|
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);
|
|
|
|
clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
|
|
|
|
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);
|