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Commit 3068a254 authored by Alexandre Belloni's avatar Alexandre Belloni
Browse files

rtc: introduce new registration method 



Introduce rtc_register_device() to register an already allocated and
initialized struct rtc_device. It automatically sets up the owner and the
two steps allocation/registration will allow to remove race conditions in
the IRQ handling of some driver. It also allows to properly extend the core
without adding more arguments to rtc_device_register().

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent b91336df

drivers/rtc/class.c

+84 −0
Original line number Diff line number Diff line
@@ -150,6 +150,7 @@ static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); 
#define RTC_CLASS_DEV_PM_OPS	NULL

#endif



/* Ensure the caller will set the id before releasing the device */

static struct rtc_device *rtc_allocate_device(void)

{

	struct rtc_device *rtc;
@@ -372,6 +373,89 @@ void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc) 
}

EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);



static void devm_rtc_release_device(struct device *dev, void *res)

{

	struct rtc_device *rtc = *(struct rtc_device **)res;



	if (rtc->registered)

		rtc_device_unregister(rtc);

	else

		put_device(&rtc->dev);

}



struct rtc_device *devm_rtc_allocate_device(struct device *dev)

{

	struct rtc_device **ptr, *rtc;

	int id, err;



	id = rtc_device_get_id(dev);

	if (id < 0)

		return ERR_PTR(id);



	ptr = devres_alloc(devm_rtc_release_device, sizeof(*ptr), GFP_KERNEL);

	if (!ptr) {

		err = -ENOMEM;

		goto exit_ida;

	}



	rtc = rtc_allocate_device();

	if (!rtc) {

		err = -ENOMEM;

		goto exit_devres;

	}



	*ptr = rtc;

	devres_add(dev, ptr);



	rtc->id = id;

	rtc->dev.parent = dev;

	dev_set_name(&rtc->dev, "rtc%d", id);



	return rtc;



exit_devres:

	devres_free(ptr);

exit_ida:

	ida_simple_remove(&rtc_ida, id);

	return ERR_PTR(err);

}

EXPORT_SYMBOL_GPL(devm_rtc_allocate_device);



int __rtc_register_device(struct module *owner, struct rtc_device *rtc)

{

	struct rtc_wkalrm alrm;

	int err;



	if (!rtc->ops)

		return -EINVAL;



	rtc->owner = owner;



	/* Check to see if there is an ALARM already set in hw */

	err = __rtc_read_alarm(rtc, &alrm);

	if (!err && !rtc_valid_tm(&alrm.time))

		rtc_initialize_alarm(rtc, &alrm);



	rtc_dev_prepare(rtc);



	err = cdev_device_add(&rtc->char_dev, &rtc->dev);

	if (err)

		dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",

			 MAJOR(rtc->dev.devt), rtc->id);

	else

		dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",

			MAJOR(rtc->dev.devt), rtc->id);



	rtc_proc_add_device(rtc);



	rtc->registered = true;

	dev_info(rtc->dev.parent, "registered as %s\n",

		 dev_name(&rtc->dev));



	return 0;

}

EXPORT_SYMBOL_GPL(__rtc_register_device);



static int __init rtc_init(void)

{

	rtc_class = class_create(THIS_MODULE, "rtc");

include/linux/rtc.h

+7 −0
Original line number Diff line number Diff line
@@ -142,6 +142,8 @@ struct rtc_device { 
	/* Some hardware can't support UIE mode */

	int uie_unsupported;



	bool registered;



#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL

	struct work_struct uie_task;

	struct timer_list uie_timer;
@@ -163,6 +165,8 @@ extern struct rtc_device *devm_rtc_device_register(struct device *dev, 
					const char *name,

					const struct rtc_class_ops *ops,

					struct module *owner);

struct rtc_device *devm_rtc_allocate_device(struct device *dev);

int __rtc_register_device(struct module *owner, struct rtc_device *rtc);

extern void rtc_device_unregister(struct rtc_device *rtc);

extern void devm_rtc_device_unregister(struct device *dev,

					struct rtc_device *rtc);
@@ -218,6 +222,9 @@ static inline bool is_leap_year(unsigned int year) 
	return (!(year % 4) && (year % 100)) || !(year % 400);

}



#define rtc_register_device(device) \

	__rtc_register_device(THIS_MODULE, device)



#ifdef CONFIG_RTC_HCTOSYS_DEVICE

extern int rtc_hctosys_ret;

#else