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/*
* RTC subsystem, base class
*
* Copyright (C) 2005 Tower Technologies
* Author: Alessandro Zummo <a.zummo@towertech.it>
*
* class skeleton from drivers/hwmon/hwmon.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/module.h>
#include <linux/rtc.h>
#include <linux/kdev_t.h>
#include <linux/idr.h>
static DEFINE_IDR(rtc_idr);
static DEFINE_MUTEX(idr_lock);
struct class *rtc_class;
static void rtc_device_release(struct class_device *class_dev)
{
struct rtc_device *rtc = to_rtc_device(class_dev);
mutex_lock(&idr_lock);
idr_remove(&rtc_idr, rtc->id);
mutex_unlock(&idr_lock);
kfree(rtc);
}
/**
* rtc_device_register - register w/ RTC class
* @dev: the device to register
*
* rtc_device_unregister() must be called when the class device is no
* longer needed.
*
* Returns the pointer to the new struct class device.
*/
struct rtc_device *rtc_device_register(const char *name, struct device *dev,
struct rtc_class_ops *ops,
struct module *owner)
{
struct rtc_device *rtc;
int id, err;
if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
err = -ENOMEM;
goto exit;
}
mutex_lock(&idr_lock);
err = idr_get_new(&rtc_idr, NULL, &id);
mutex_unlock(&idr_lock);
if (err < 0)
goto exit;
id = id & MAX_ID_MASK;
rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
if (rtc == NULL) {
err = -ENOMEM;
goto exit_idr;
}
rtc->id = id;
rtc->ops = ops;
rtc->owner = owner;
rtc->max_user_freq = 64;
rtc->class_dev.dev = dev;
rtc->class_dev.class = rtc_class;
rtc->class_dev.release = rtc_device_release;
mutex_init(&rtc->ops_lock);
spin_lock_init(&rtc->irq_lock);
spin_lock_init(&rtc->irq_task_lock);
strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE);
snprintf(rtc->class_dev.class_id, BUS_ID_SIZE, "rtc%d", id);
err = class_device_register(&rtc->class_dev);
if (err)
goto exit_kfree;
dev_info(dev, "rtc core: registered %s as %s\n",
rtc->name, rtc->class_dev.class_id);
return rtc;
exit_kfree:
kfree(rtc);
exit_idr:
mutex_lock(&idr_lock);
idr_remove(&rtc_idr, id);
mutex_unlock(&idr_lock);
exit:
dev_err(dev, "rtc core: unable to register %s, err = %d\n",
name, err);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(rtc_device_register);
/**
* rtc_device_unregister - removes the previously registered RTC class device
*
* @rtc: the RTC class device to destroy
*/
void rtc_device_unregister(struct rtc_device *rtc)
{
mutex_lock(&rtc->ops_lock);
rtc->ops = NULL;
mutex_unlock(&rtc->ops_lock);
class_device_unregister(&rtc->class_dev);
}
EXPORT_SYMBOL_GPL(rtc_device_unregister);
int rtc_interface_register(struct class_interface *intf)
{
intf->class = rtc_class;
return class_interface_register(intf);
}
EXPORT_SYMBOL_GPL(rtc_interface_register);
static int __init rtc_init(void)
{
rtc_class = class_create(THIS_MODULE, "rtc");
if (IS_ERR(rtc_class)) {
printk(KERN_ERR "%s: couldn't create class\n", __FILE__);
return PTR_ERR(rtc_class);
}
return 0;
}
static void __exit rtc_exit(void)
{
class_destroy(rtc_class);
}
subsys_initcall(rtc_init);
module_exit(rtc_exit);
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("RTC class support");
MODULE_LICENSE("GPL");
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