forked from mirrors/linux
6ac12dfe9c
We need to serialize access to the global rtc_idr even in this error path. Signed-off-by: Sonny Rao <sonny@burdell.org> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
150 lines
3.3 KiB
C
150 lines
3.3 KiB
C
/*
|
|
* 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);
|
|
}
|
|
|
|
module_init(rtc_init);
|
|
module_exit(rtc_exit);
|
|
|
|
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towerteh.it>");
|
|
MODULE_DESCRIPTION("RTC class support");
|
|
MODULE_LICENSE("GPL");
|