/* * 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,					const 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){	if (class_device_get(&rtc->class_dev) != NULL) {		mutex_lock(&rtc->ops_lock);		/* remove innards of this RTC, then disable it, before		 * letting any rtc_class_open() users access it again		 */		class_device_unregister(&rtc->class_dev);		rtc->ops = NULL;		mutex_unlock(&rtc->ops_lock);		class_device_put(&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");