[linux.git] / include / linux / rtc.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Generic RTC interface.
 * This version contains the part of the user interface to the Real Time Clock
 * service. It is used with both the legacy mc146818 and also  EFI
 * Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
 * from <linux/mc146818rtc.h> to this file for 2.4 kernels.
 *
 * Copyright (C) 1999 Hewlett-Packard Co.
 * Copyright (C) 1999 Stephane Eranian <[email protected]>
 */
#ifndef _LINUX_RTC_H_
#define _LINUX_RTC_H_


#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/nvmem-provider.h>
#include <uapi/linux/rtc.h>

extern int rtc_month_days(unsigned int month, unsigned int year);
extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
extern int rtc_valid_tm(struct rtc_time *tm);
extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
ktime_t rtc_tm_to_ktime(struct rtc_time tm);
struct rtc_time rtc_ktime_to_tm(ktime_t kt);

/*
 * rtc_tm_sub - Return the difference in seconds.
 */
static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs)
{
	return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
}

#include <linux/device.h>
#include <linux/seq_file.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/timerqueue.h>
#include <linux/workqueue.h>

extern struct class *rtc_class;

/*
 * For these RTC methods the device parameter is the physical device
 * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
 * was passed to rtc_device_register().  Its driver_data normally holds
 * device state, including the rtc_device pointer for the RTC.
 *
 * Most of these methods are called with rtc_device.ops_lock held,
 * through the rtc_*(struct rtc_device *, ...) calls.
 *
 * The (current) exceptions are mostly filesystem hooks:
 *   - the proc() hook for procfs
 */
struct rtc_class_ops {
	int (*ioctl)(struct device *, unsigned int, unsigned long);
	int (*read_time)(struct device *, struct rtc_time *);
	int (*set_time)(struct device *, struct rtc_time *);
	int (*read_alarm)(struct device *, struct rtc_wkalrm *);
	int (*set_alarm)(struct device *, struct rtc_wkalrm *);
	int (*proc)(struct device *, struct seq_file *);
	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
	int (*read_offset)(struct device *, long *offset);
	int (*set_offset)(struct device *, long offset);
	int (*param_get)(struct device *, struct rtc_param *param);
	int (*param_set)(struct device *, struct rtc_param *param);
};

struct rtc_device;

struct rtc_timer {
	struct timerqueue_node node;
	ktime_t period;
	void (*func)(struct rtc_device *rtc);
	struct rtc_device *rtc;
	int enabled;
};

/* flags */
#define RTC_DEV_BUSY 0
#define RTC_NO_CDEV  1

struct rtc_device {
	struct device dev;
	struct module *owner;

	int id;

	const struct rtc_class_ops *ops;
	struct mutex ops_lock;

	struct cdev char_dev;
	unsigned long flags;

	unsigned long irq_data;
	spinlock_t irq_lock;
	wait_queue_head_t irq_queue;
	struct fasync_struct *async_queue;

	int irq_freq;
	int max_user_freq;

	struct timerqueue_head timerqueue;
	struct rtc_timer aie_timer;
	struct rtc_timer uie_rtctimer;
	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
	int pie_enabled;
	struct work_struct irqwork;
	/* Some hardware can't support UIE mode */
	int uie_unsupported;

	/*
	 * This offset specifies the update timing of the RTC.
	 *
	 * tsched     t1 write(t2.tv_sec - 1sec))  t2 RTC increments seconds
	 *
	 * The offset defines how tsched is computed so that the write to
	 * the RTC (t2.tv_sec - 1sec) is correct versus the time required
	 * for the transport of the write and the time which the RTC needs
	 * to increment seconds the first time after the write (t2).
	 *
	 * For direct accessible RTCs tsched ~= t1 because the write time
	 * is negligible. For RTCs behind slow busses the transport time is
	 * significant and has to be taken into account.
	 *
	 * The time between the write (t1) and the first increment after
	 * the write (t2) is RTC specific. For a MC146818 RTC it's 500ms,
	 * for many others it's exactly 1 second. Consult the datasheet.
	 *
	 * The value of this offset is also used to calculate the to be
	 * written value (t2.tv_sec - 1sec) at tsched.
	 *
	 * The default value for this is NSEC_PER_SEC + 10 msec default
	 * transport time. The offset can be adjusted by drivers so the
	 * calculation for the to be written value at tsched becomes
	 * correct:
	 *
	 *	newval = tsched + set_offset_nsec - NSEC_PER_SEC
	 * and  (tsched + set_offset_nsec) % NSEC_PER_SEC == 0
	 */
	unsigned long set_offset_nsec;

	unsigned long features[BITS_TO_LONGS(RTC_FEATURE_CNT)];

	time64_t range_min;
	timeu64_t range_max;
	time64_t start_secs;
	time64_t offset_secs;
	bool set_start_time;

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	struct work_struct uie_task;
	struct timer_list uie_timer;
	/* Those fields are protected by rtc->irq_lock */
	unsigned int oldsecs;
	unsigned int uie_irq_active:1;
	unsigned int stop_uie_polling:1;
	unsigned int uie_task_active:1;
	unsigned int uie_timer_active:1;
#endif
};
#define to_rtc_device(d) container_of(d, struct rtc_device, dev)

#define rtc_lock(d) mutex_lock(&d->ops_lock)
#define rtc_unlock(d) mutex_unlock(&d->ops_lock)

/* useful timestamps */
#define RTC_TIMESTAMP_BEGIN_0000	-62167219200ULL /* 0000-01-01 00:00:00 */
#define RTC_TIMESTAMP_BEGIN_1900	-2208988800LL /* 1900-01-01 00:00:00 */
#define RTC_TIMESTAMP_BEGIN_2000	946684800LL /* 2000-01-01 00:00:00 */
#define RTC_TIMESTAMP_END_2063		2966371199LL /* 2063-12-31 23:59:59 */
#define RTC_TIMESTAMP_END_2079		3471292799LL /* 2079-12-31 23:59:59 */
#define RTC_TIMESTAMP_END_2099		4102444799LL /* 2099-12-31 23:59:59 */
#define RTC_TIMESTAMP_END_2199		7258118399LL /* 2199-12-31 23:59:59 */
#define RTC_TIMESTAMP_END_9999		253402300799LL /* 9999-12-31 23:59:59 */

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 __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc);

extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
extern int rtc_read_alarm(struct rtc_device *rtc,
			struct rtc_wkalrm *alrm);
extern int rtc_set_alarm(struct rtc_device *rtc,
				struct rtc_wkalrm *alrm);
extern int rtc_initialize_alarm(struct rtc_device *rtc,
				struct rtc_wkalrm *alrm);
extern void rtc_update_irq(struct rtc_device *rtc,
			unsigned long num, unsigned long events);

extern struct rtc_device *rtc_class_open(const char *name);
extern void rtc_class_close(struct rtc_device *rtc);

extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
						unsigned int enabled);

void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
void rtc_aie_update_irq(struct rtc_device *rtc);
void rtc_uie_update_irq(struct rtc_device *rtc);
enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);

void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
		    struct rtc_device *rtc);
int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
		    ktime_t expires, ktime_t period);
void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
int rtc_read_offset(struct rtc_device *rtc, long *offset);
int rtc_set_offset(struct rtc_device *rtc, long offset);
void rtc_timer_do_work(struct work_struct *work);

static inline bool is_leap_year(unsigned int year)
{
	return (!(year % 4) && (year % 100)) || !(year % 400);
}

#define devm_rtc_register_device(device) \
	__devm_rtc_register_device(THIS_MODULE, device)

#ifdef CONFIG_RTC_HCTOSYS_DEVICE
extern int rtc_hctosys_ret;
#else
#define rtc_hctosys_ret -ENODEV
#endif

#ifdef CONFIG_RTC_NVMEM
int devm_rtc_nvmem_register(struct rtc_device *rtc,
			    struct nvmem_config *nvmem_config);
#else
static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
					  struct nvmem_config *nvmem_config)
{
	return 0;
}
#endif

#ifdef CONFIG_RTC_INTF_SYSFS
int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
#else
static inline
int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
{
	return 0;
}

static inline
int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
{
	return 0;
}
#endif
#endif /* _LINUX_RTC_H_ */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	/*
	3	* Generic RTC interface.
	4	* This version contains the part of the user interface to the Real Time Clock
	5	* service. It is used with both the legacy mc146818 and also EFI
	6	* Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
	7	* from <linux/mc146818rtc.h> to this file for 2.4 kernels.
ab6a2d70	8	*
1da177e4 LT	9	* Copyright (C) 1999 Hewlett-Packard Co.
	10	* Copyright (C) 1999 Stephane Eranian <[email protected]>
	11	*/
	12	#ifndef _LINUX_RTC_H_
	13	#define _LINUX_RTC_H_
	14
1da177e4	15
78d89ef4	16	#include <linux/types.h>
4024ce5e	17	#include <linux/interrupt.h>
697e5a47	18	#include <linux/nvmem-provider.h>
607ca46e	19	#include <uapi/linux/rtc.h>
4024ce5e	20
c58411e9	21	extern int rtc_month_days(unsigned int month, unsigned int year);
8232212e	22	extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
c58411e9	23	extern int rtc_valid_tm(struct rtc_time *tm);
c2c11ae4	24	extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
c2c11ae4	25	extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
6610e089 JS	26	ktime_t rtc_tm_to_ktime(struct rtc_time tm);
	27	struct rtc_time rtc_ktime_to_tm(ktime_t kt);
	28
92000257 XP	29	/*
	30	* rtc_tm_sub - Return the difference in seconds.
	31	*/
	32	static inline time64_t rtc_tm_sub(struct rtc_time lhs, struct rtc_time rhs)
	33	{
	34	return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
	35	}
	36
0c86edc0 AZ	37	#include <linux/device.h>
	38	#include <linux/seq_file.h>
	39	#include <linux/cdev.h>
	40	#include <linux/poll.h>
	41	#include <linux/mutex.h>
6610e089 JS	42	#include <linux/timerqueue.h>
6610e089 JS	43	#include <linux/workqueue.h>
0c86edc0 AZ	44
	45	extern struct class *rtc_class;
	46
5ad31a57 DB	47	/*
	48	* For these RTC methods the device parameter is the physical device
	49	* on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
	50	* was passed to rtc_device_register(). Its driver_data normally holds
	51	* device state, including the rtc_device pointer for the RTC.
	52	*
	53	* Most of these methods are called with rtc_device.ops_lock held,
	54	* through the rtc_(struct rtc_device , ...) calls.
	55	*
	56	* The (current) exceptions are mostly filesystem hooks:
	57	* - the proc() hook for procfs
5ad31a57	58	*/
0c86edc0	59	struct rtc_class_ops {
0c86edc0 AZ	60	int (ioctl)(struct device , unsigned int, unsigned long);
	61	int (read_time)(struct device , struct rtc_time *);
	62	int (set_time)(struct device , struct rtc_time *);
	63	int (read_alarm)(struct device , struct rtc_wkalrm *);
	64	int (set_alarm)(struct device , struct rtc_wkalrm *);
	65	int (proc)(struct device , struct seq_file *);
099e6576	66	int (alarm_irq_enable)(struct device , unsigned int enabled);
b3967067 JC	67	int (read_offset)(struct device , long *offset);
b3967067 JC	68	int (set_offset)(struct device , long offset);
0d20e9fb AB	69	int (param_get)(struct device , struct rtc_param *param);
0d20e9fb AB	70	int (param_set)(struct device , struct rtc_param *param);
0c86edc0 AZ	71	};
0c86edc0 AZ	72
9a032011 AB	73	struct rtc_device;
9a032011 AB	74
6610e089	75	struct rtc_timer {
6610e089 JS	76	struct timerqueue_node node;
6610e089 JS	77	ktime_t period;
9a032011 AB	78	void (func)(struct rtc_device rtc);
9a032011 AB	79	struct rtc_device *rtc;
6610e089 JS	80	int enabled;
	81	};
	82
8853c202 JK	83	/* flags */
8853c202 JK	84	#define RTC_DEV_BUSY 0
789c1093	85	#define RTC_NO_CDEV 1
8853c202	86
1796dcce	87	struct rtc_device {
cd966209	88	struct device dev;
0c86edc0 AZ	89	struct module *owner;
	90
	91	int id;
0c86edc0	92
ff8371ac	93	const struct rtc_class_ops *ops;
0c86edc0 AZ	94	struct mutex ops_lock;
0c86edc0 AZ	95
0c86edc0	96	struct cdev char_dev;
8853c202	97	unsigned long flags;
0c86edc0 AZ	98
	99	unsigned long irq_data;
	100	spinlock_t irq_lock;
	101	wait_queue_head_t irq_queue;
	102	struct fasync_struct *async_queue;
	103
0c86edc0	104	int irq_freq;
110d693d	105	int max_user_freq;
6610e089 JS	106
	107	struct timerqueue_head timerqueue;
	108	struct rtc_timer aie_timer;
	109	struct rtc_timer uie_rtctimer;
	110	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
	111	int pie_enabled;
	112	struct work_struct irqwork;
4a649903 JS	113	/* Some hardware can't support UIE mode */
4a649903 JS	114	int uie_unsupported;
6e57b1d6	115
69eca258 TG	116	/*
	117	* This offset specifies the update timing of the RTC.
	118	*
	119	* tsched t1 write(t2.tv_sec - 1sec)) t2 RTC increments seconds
	120	*
	121	* The offset defines how tsched is computed so that the write to
	122	* the RTC (t2.tv_sec - 1sec) is correct versus the time required
	123	* for the transport of the write and the time which the RTC needs
	124	* to increment seconds the first time after the write (t2).
	125	*
	126	* For direct accessible RTCs tsched ~= t1 because the write time
	127	* is negligible. For RTCs behind slow busses the transport time is
	128	* significant and has to be taken into account.
	129	*
	130	* The time between the write (t1) and the first increment after
	131	* the write (t2) is RTC specific. For a MC146818 RTC it's 500ms,
	132	* for many others it's exactly 1 second. Consult the datasheet.
	133	*
	134	* The value of this offset is also used to calculate the to be
	135	* written value (t2.tv_sec - 1sec) at tsched.
	136	*
	137	* The default value for this is NSEC_PER_SEC + 10 msec default
	138	* transport time. The offset can be adjusted by drivers so the
	139	* calculation for the to be written value at tsched becomes
	140	* correct:
	141	*
	142	* newval = tsched + set_offset_nsec - NSEC_PER_SEC
	143	* and (tsched + set_offset_nsec) % NSEC_PER_SEC == 0
0f295b06	144	*/
69eca258	145	unsigned long set_offset_nsec;
0f295b06	146
7ae41220 AB	147	unsigned long features[BITS_TO_LONGS(RTC_FEATURE_CNT)];
7ae41220 AB	148
71db049e AB	149	time64_t range_min;
71db049e AB	150	timeu64_t range_max;
98951564 BW	151	time64_t start_secs;
	152	time64_t offset_secs;
	153	bool set_start_time;
71db049e	154
6e57b1d6 JS	155	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	156	struct work_struct uie_task;
	157	struct timer_list uie_timer;
	158	/* Those fields are protected by rtc->irq_lock */
	159	unsigned int oldsecs;
	160	unsigned int uie_irq_active:1;
	161	unsigned int stop_uie_polling:1;
	162	unsigned int uie_task_active:1;
	163	unsigned int uie_timer_active:1;
	164	#endif
0c86edc0	165	};
cd966209	166	#define to_rtc_device(d) container_of(d, struct rtc_device, dev)
0c86edc0	167
ae486688 AB	168	#define rtc_lock(d) mutex_lock(&d->ops_lock)
	169	#define rtc_unlock(d) mutex_unlock(&d->ops_lock)
	170
83bbc5ac	171	/* useful timestamps */
f00eaa38	172	#define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
d3062d1d	173	#define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
83bbc5ac	174	#define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
5ff404d1	175	#define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
cbc943eb	176	#define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */
83bbc5ac	177	#define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
8d6ac1ce	178	#define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
beee05df	179	#define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
83bbc5ac	180
6636a994 JH	181	extern struct rtc_device devm_rtc_device_register(struct device dev,
6636a994 JH	182	const char *name,
3e217b66 JH	183	const struct rtc_class_ops *ops,
3e217b66 JH	184	struct module *owner);
3068a254	185	struct rtc_device devm_rtc_allocate_device(struct device dev);
fdcfd854	186	int __devm_rtc_register_device(struct module owner, struct rtc_device rtc);
0c86edc0	187
ab6a2d70 DB	188	extern int rtc_read_time(struct rtc_device rtc, struct rtc_time tm);
ab6a2d70 DB	189	extern int rtc_set_time(struct rtc_device rtc, struct rtc_time tm);
f44f7f96	190	int __rtc_read_alarm(struct rtc_device rtc, struct rtc_wkalrm alarm);
ab6a2d70	191	extern int rtc_read_alarm(struct rtc_device *rtc,
0c86edc0	192	struct rtc_wkalrm *alrm);
ab6a2d70	193	extern int rtc_set_alarm(struct rtc_device *rtc,
0c86edc0	194	struct rtc_wkalrm *alrm);
f6d5b331 JS	195	extern int rtc_initialize_alarm(struct rtc_device *rtc,
f6d5b331 JS	196	struct rtc_wkalrm *alrm);
ab6a2d70	197	extern void rtc_update_irq(struct rtc_device *rtc,
0c86edc0 AZ	198	unsigned long num, unsigned long events);
0c86edc0 AZ	199
9f3b795a	200	extern struct rtc_device rtc_class_open(const char name);
ab6a2d70	201	extern void rtc_class_close(struct rtc_device *rtc);
0c86edc0	202
8719d3c9 AB	203	extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
8719d3c9 AB	204	extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
099e6576 AZ	205	extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
099e6576 AZ	206	extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
6e57b1d6 JS	207	extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
6e57b1d6 JS	208	unsigned int enabled);
0c86edc0	209
456d66ec	210	void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
9a032011 AB	211	void rtc_aie_update_irq(struct rtc_device *rtc);
9a032011 AB	212	void rtc_uie_update_irq(struct rtc_device *rtc);
6610e089	213	enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
1da177e4	214
9a032011 AB	215	void rtc_timer_init(struct rtc_timer timer, void (f)(struct rtc_device *r),
9a032011 AB	216	struct rtc_device *rtc);
1796dcce KK	217	int rtc_timer_start(struct rtc_device rtc, struct rtc_timer timer,
1796dcce KK	218	ktime_t expires, ktime_t period);
73744a64	219	void rtc_timer_cancel(struct rtc_device rtc, struct rtc_timer timer);
b3967067 JC	220	int rtc_read_offset(struct rtc_device rtc, long offset);
b3967067 JC	221	int rtc_set_offset(struct rtc_device *rtc, long offset);
96c8f06a	222	void rtc_timer_do_work(struct work_struct *work);
6610e089	223
78d89ef4 AM	224	static inline bool is_leap_year(unsigned int year)
	225	{
	226	return (!(year % 4) && (year % 100)) \|\| !(year % 400);
	227	}
	228
fdcfd854 BG	229	#define devm_rtc_register_device(device) \
fdcfd854 BG	230	__devm_rtc_register_device(THIS_MODULE, device)
3068a254	231
4c24e29e	232	#ifdef CONFIG_RTC_HCTOSYS_DEVICE
d0ab4a4d UKK	233	extern int rtc_hctosys_ret;
	234	#else
	235	#define rtc_hctosys_ret -ENODEV
	236	#endif
	237
fd5cd21d	238	#ifdef CONFIG_RTC_NVMEM
3a905c2d BG	239	int devm_rtc_nvmem_register(struct rtc_device *rtc,
3a905c2d BG	240	struct nvmem_config *nvmem_config);
fd5cd21d	241	#else
3a905c2d BG	242	static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
3a905c2d BG	243	struct nvmem_config *nvmem_config)
fd5cd21d	244	{
c59b3715	245	return 0;
fd5cd21d	246	}
fd5cd21d AB	247	#endif
fd5cd21d AB	248
eb2bccb7 AB	249	#ifdef CONFIG_RTC_INTF_SYSFS
	250	int rtc_add_group(struct rtc_device rtc, const struct attribute_group grp);
	251	int rtc_add_groups(struct rtc_device rtc, const struct attribute_group *grps);
	252	#else
	253	static inline
	254	int rtc_add_group(struct rtc_device rtc, const struct attribute_group grp)
	255	{
	256	return 0;
	257	}
	258
	259	static inline
	260	int rtc_add_groups(struct rtc_device rtc, const struct attribute_group *grps)
	261	{
	262	return 0;
	263	}
	264	#endif
1da177e4	265	#endif /* _LINUX_RTC_H_ */