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Commit 0c86edc0 authored by Alessandro Zummo's avatar Alessandro Zummo Committed by Linus Torvalds
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[PATCH] RTC subsystem: class 



Add the basic RTC subsystem infrastructure to the kernel.

rtc/class.c - registration facilities for RTC drivers
rtc/interface.c - kernel/rtc interface functions
rtc/hctosys.c - snippet of code that copies hw clock to sw clock
		at bootup, if configured to do so.

Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 4079c39a

CREDITS

+3 −2
Original line number Diff line number Diff line
@@ -3741,10 +3741,11 @@ D: Mylex DAC960 PCI RAID driver 
D: Miscellaneous kernel fixes



N: Alessandro Zummo

E: azummo@ita.flashnet.it

W: http://freepage.logicom.it/azummo/

E: a.zummo@towertech.it

D: CMI8330 support is sb_card.c

D: ISAPnP fixes in sb_card.c

D: ZyXEL omni.net lcd plus driver

D: RTC subsystem

S: Italy



N: Marc Zyngier

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -2233,6 +2233,12 @@ M: p_gortmaker@yahoo.com 
L:	linux-kernel@vger.kernel.org

S:	Maintained



REAL TIME CLOCK (RTC) SUBSYSTEM

P:	Alessandro Zummo

M:	a.zummo@towertech.it

L:	linux-kernel@vger.kernel.org

S:	Maintained



REISERFS FILE SYSTEM

P:	Hans Reiser

M:	reiserfs-dev@namesys.com

drivers/rtc/Kconfig

+42 −2
Original line number Diff line number Diff line 
#

\#

# RTC class/drivers configuration

#



menu "Real Time Clock"



config RTC_LIB

	tristate



config RTC_CLASS

	tristate "RTC class"

	depends on EXPERIMENTAL

	default n

	select RTC_LIB

	help

	  Generic RTC class support. If you say yes here, you will

 	  be allowed to plug one or more RTCs to your system. You will

	  probably want to enable one of more of the interfaces below.



	  This driver can also be built as a module. If so, the module

	  will be called rtc-class.



config RTC_HCTOSYS

	bool "Set system time from RTC on startup"

	depends on RTC_CLASS = y

	default y

	help

	  If you say yes here, the system time will be set using

	  the value read from the specified RTC device. This is useful

	  in order to avoid unnecessary fschk runs.



config RTC_HCTOSYS_DEVICE

	string "The RTC to read the time from"

	depends on RTC_HCTOSYS = y

	default "rtc0"

	help

	  The RTC device that will be used as the source for

	  the system time, usually rtc0.



comment "RTC interfaces"

	depends on RTC_CLASS



comment "RTC drivers"

	depends on RTC_CLASS



endmenu

drivers/rtc/Makefile

+4 −1
Original line number Diff line number Diff line
@@ -3,3 +3,6 @@ 
#



obj-$(CONFIG_RTC_LIB)		+= rtc-lib.o

obj-$(CONFIG_RTC_HCTOSYS)	+= hctosys.o

obj-$(CONFIG_RTC_CLASS)		+= rtc-core.o

rtc-core-y			:= class.o interface.o

drivers/rtc/class.c

0 → 100644
+145 −0
Original line number Diff line number Diff line 
/*

 * 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->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:

	idr_remove(&rtc_idr, id);



exit:

	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");