[mirror_ubuntu-bionic-kernel.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 <eranian@hpl.hp.com>
 */
#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);
}

static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
{
	rtc_time64_to_tm(time, tm);
}

static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
{
	*time = rtc_tm_to_time64(tm);

	return 0;
}

#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
 *   - non-ioctl() chardev hooks:  open(), release(), read_callback()
 *
 * REVISIT those periodic irq calls *do* have ops_lock when they're
 * issued through ioctl() ...
 */
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 (*set_mmss64)(struct device *, time64_t secs);
	int (*set_mmss)(struct device *, unsigned long secs);
	int (*read_callback)(struct device *, int data);
	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
	int (*read_offset)(struct device *, long *offset);
	int (*set_offset)(struct device *, long offset);
};

#define RTC_DEVICE_NAME_SIZE 20
typedef struct rtc_task {
	void (*func)(void *private_data);
	void *private_data;
} rtc_task_t;


struct rtc_timer {
	struct rtc_task	task;
	struct timerqueue_node node;
	ktime_t period;
	int enabled;
};


/* flags */
#define RTC_DEV_BUSY 0

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;

	struct rtc_task *irq_task;
	spinlock_t irq_task_lock;
	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;

	/* Number of nsec it takes to set the RTC clock. This influences when
	 * the set ops are called. An offset:
	 *   - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
	 *   - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
	 *   - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
	 */
	long set_offset_nsec;

	bool registered;

	struct nvmem_config *nvmem_config;
	struct nvmem_device *nvmem;
	/* Old ABI support */
	bool nvram_old_abi;
	struct bin_attribute *nvram;

#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)

extern struct rtc_device *rtc_device_register(const char *name,
					struct device *dev,
					const struct rtc_class_ops *ops,
					struct module *owner);
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);

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);
extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);
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_register(struct rtc_device *rtc,
				struct rtc_task *task);
extern void rtc_irq_unregister(struct rtc_device *rtc,
				struct rtc_task *task);
extern int rtc_irq_set_state(struct rtc_device *rtc,
				struct rtc_task *task, int enabled);
extern int rtc_irq_set_freq(struct rtc_device *rtc,
				struct rtc_task *task, 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(void *private);
void rtc_uie_update_irq(void *private);
enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);

int rtc_register(rtc_task_t *task);
int rtc_unregister(rtc_task_t *task);
int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);

void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
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);
}

/* Determine if we can call to driver to set the time. Drivers can only be
 * called to set a second aligned time value, and the field set_offset_nsec
 * specifies how far away from the second aligned time to call the driver.
 *
 * This also computes 'to_set' which is the time we are trying to set, and has
 * a zero in tv_nsecs, such that:
 *    to_set - set_delay_nsec == now +/- FUZZ
 *
 */
static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
				  struct timespec64 *to_set,
				  const struct timespec64 *now)
{
	/* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
	const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
	struct timespec64 delay = {.tv_sec = 0,
				   .tv_nsec = set_offset_nsec};

	*to_set = timespec64_add(*now, delay);

	if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
		to_set->tv_nsec = 0;
		return true;
	}

	if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
		to_set->tv_sec++;
		to_set->tv_nsec = 0;
		return true;
	}
	return false;
}

#define rtc_register_device(device) \
	__rtc_register_device(THIS_MODULE, device)

#ifdef CONFIG_RTC_HCTOSYS_DEVICE
extern int rtc_hctosys_ret;
#else
#define rtc_hctosys_ret -ENODEV
#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 <eranian@hpl.hp.com>
	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
c2c11ae4	37	static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
	38	{
	39	rtc_time64_to_tm(time, tm);
	40	}
	41
c2c11ae4	42	static inline int rtc_tm_to_time(struct rtc_time tm, unsigned long time)
	43	{
	44	*time = rtc_tm_to_time64(tm);
	45
	46	return 0;
	47	}
c58411e9	48
0c86edc0 AZ	49	#include <linux/device.h>
	50	#include <linux/seq_file.h>
	51	#include <linux/cdev.h>
	52	#include <linux/poll.h>
	53	#include <linux/mutex.h>
6610e089 JS	54	#include <linux/timerqueue.h>
6610e089 JS	55	#include <linux/workqueue.h>
0c86edc0 AZ	56
	57	extern struct class *rtc_class;
	58
5ad31a57 DB	59	/*
	60	* For these RTC methods the device parameter is the physical device
	61	* on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
	62	* was passed to rtc_device_register(). Its driver_data normally holds
	63	* device state, including the rtc_device pointer for the RTC.
	64	*
	65	* Most of these methods are called with rtc_device.ops_lock held,
	66	* through the rtc_(struct rtc_device , ...) calls.
	67	*
	68	* The (current) exceptions are mostly filesystem hooks:
	69	* - the proc() hook for procfs
	70	* - non-ioctl() chardev hooks: open(), release(), read_callback()
5ad31a57 DB	71	*
	72	* REVISIT those periodic irq calls do have ops_lock when they're
	73	* issued through ioctl() ...
	74	*/
0c86edc0	75	struct rtc_class_ops {
0c86edc0 AZ	76	int (ioctl)(struct device , unsigned int, unsigned long);
	77	int (read_time)(struct device , struct rtc_time *);
	78	int (set_time)(struct device , struct rtc_time *);
	79	int (read_alarm)(struct device , struct rtc_wkalrm *);
	80	int (set_alarm)(struct device , struct rtc_wkalrm *);
	81	int (proc)(struct device , struct seq_file *);
8e4ff1a8	82	int (set_mmss64)(struct device , time64_t secs);
0c86edc0	83	int (set_mmss)(struct device , unsigned long secs);
0c86edc0	84	int (read_callback)(struct device , int data);
099e6576	85	int (alarm_irq_enable)(struct device , unsigned int enabled);
b3967067 JC	86	int (read_offset)(struct device , long *offset);
b3967067 JC	87	int (set_offset)(struct device , long offset);
0c86edc0 AZ	88	};
	89
	90	#define RTC_DEVICE_NAME_SIZE 20
6610e089 JS	91	typedef struct rtc_task {
	92	void (func)(void private_data);
	93	void *private_data;
	94	} rtc_task_t;
	95
	96
	97	struct rtc_timer {
	98	struct rtc_task task;
	99	struct timerqueue_node node;
	100	ktime_t period;
	101	int enabled;
	102	};
	103
0c86edc0	104
8853c202 JK	105	/* flags */
	106	#define RTC_DEV_BUSY 0
	107
1796dcce	108	struct rtc_device {
cd966209	109	struct device dev;
0c86edc0 AZ	110	struct module *owner;
	111
	112	int id;
0c86edc0	113
ff8371ac	114	const struct rtc_class_ops *ops;
0c86edc0 AZ	115	struct mutex ops_lock;
0c86edc0 AZ	116
0c86edc0	117	struct cdev char_dev;
8853c202	118	unsigned long flags;
0c86edc0 AZ	119
	120	unsigned long irq_data;
	121	spinlock_t irq_lock;
	122	wait_queue_head_t irq_queue;
	123	struct fasync_struct *async_queue;
	124
	125	struct rtc_task *irq_task;
	126	spinlock_t irq_task_lock;
	127	int irq_freq;
110d693d	128	int max_user_freq;
6610e089 JS	129
	130	struct timerqueue_head timerqueue;
	131	struct rtc_timer aie_timer;
	132	struct rtc_timer uie_rtctimer;
	133	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
	134	int pie_enabled;
	135	struct work_struct irqwork;
4a649903 JS	136	/* Some hardware can't support UIE mode */
4a649903 JS	137	int uie_unsupported;
6e57b1d6	138
0f295b06 JG	139	/* Number of nsec it takes to set the RTC clock. This influences when
	140	* the set ops are called. An offset:
	141	* - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
	142	* - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
	143	* - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
	144	*/
	145	long set_offset_nsec;
	146
3068a254 AB	147	bool registered;
3068a254 AB	148
697e5a47 AB	149	struct nvmem_config *nvmem_config;
	150	struct nvmem_device *nvmem;
	151	/* Old ABI support */
	152	bool nvram_old_abi;
	153	struct bin_attribute *nvram;
	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 AZ	167
	168	extern struct rtc_device rtc_device_register(const char name,
	169	struct device *dev,
ff8371ac	170	const struct rtc_class_ops *ops,
0c86edc0	171	struct module *owner);
6636a994 JH	172	extern struct rtc_device devm_rtc_device_register(struct device dev,
6636a994 JH	173	const char *name,
3e217b66 JH	174	const struct rtc_class_ops *ops,
3e217b66 JH	175	struct module *owner);
3068a254 AB	176	struct rtc_device devm_rtc_allocate_device(struct device dev);
3068a254 AB	177	int __rtc_register_device(struct module owner, struct rtc_device rtc);
ab6a2d70	178	extern void rtc_device_unregister(struct rtc_device *rtc);
3e217b66 JH	179	extern void devm_rtc_device_unregister(struct device *dev,
3e217b66 JH	180	struct rtc_device *rtc);
0c86edc0	181
ab6a2d70 DB	182	extern int rtc_read_time(struct rtc_device rtc, struct rtc_time tm);
ab6a2d70 DB	183	extern int rtc_set_time(struct rtc_device rtc, struct rtc_time tm);
0f295b06	184	extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);
f44f7f96	185	int __rtc_read_alarm(struct rtc_device rtc, struct rtc_wkalrm alarm);
ab6a2d70	186	extern int rtc_read_alarm(struct rtc_device *rtc,
0c86edc0	187	struct rtc_wkalrm *alrm);
ab6a2d70	188	extern int rtc_set_alarm(struct rtc_device *rtc,
0c86edc0	189	struct rtc_wkalrm *alrm);
f6d5b331 JS	190	extern int rtc_initialize_alarm(struct rtc_device *rtc,
f6d5b331 JS	191	struct rtc_wkalrm *alrm);
ab6a2d70	192	extern void rtc_update_irq(struct rtc_device *rtc,
0c86edc0 AZ	193	unsigned long num, unsigned long events);
0c86edc0 AZ	194
9f3b795a	195	extern struct rtc_device rtc_class_open(const char name);
ab6a2d70	196	extern void rtc_class_close(struct rtc_device *rtc);
0c86edc0	197
ab6a2d70	198	extern int rtc_irq_register(struct rtc_device *rtc,
0c86edc0	199	struct rtc_task *task);
ab6a2d70	200	extern void rtc_irq_unregister(struct rtc_device *rtc,
0c86edc0	201	struct rtc_task *task);
ab6a2d70	202	extern int rtc_irq_set_state(struct rtc_device *rtc,
0c86edc0	203	struct rtc_task *task, int enabled);
ab6a2d70	204	extern int rtc_irq_set_freq(struct rtc_device *rtc,
0c86edc0	205	struct rtc_task *task, int freq);
099e6576 AZ	206	extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
099e6576 AZ	207	extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
6e57b1d6 JS	208	extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
6e57b1d6 JS	209	unsigned int enabled);
0c86edc0	210
456d66ec	211	void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
6610e089 JS	212	void rtc_aie_update_irq(void *private);
	213	void rtc_uie_update_irq(void *private);
	214	enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
1da177e4 LT	215
	216	int rtc_register(rtc_task_t *task);
	217	int rtc_unregister(rtc_task_t *task);
	218	int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
1da177e4	219
1796dcce KK	220	void rtc_timer_init(struct rtc_timer timer, void (f)(void p), void data);
	221	int rtc_timer_start(struct rtc_device rtc, struct rtc_timer timer,
	222	ktime_t expires, ktime_t period);
73744a64	223	void rtc_timer_cancel(struct rtc_device rtc, struct rtc_timer timer);
b3967067 JC	224	int rtc_read_offset(struct rtc_device rtc, long offset);
b3967067 JC	225	int rtc_set_offset(struct rtc_device *rtc, long offset);
96c8f06a	226	void rtc_timer_do_work(struct work_struct *work);
6610e089	227
78d89ef4 AM	228	static inline bool is_leap_year(unsigned int year)
	229	{
	230	return (!(year % 4) && (year % 100)) \|\| !(year % 400);
	231	}
	232
0f295b06 JG	233	/* Determine if we can call to driver to set the time. Drivers can only be
	234	* called to set a second aligned time value, and the field set_offset_nsec
	235	* specifies how far away from the second aligned time to call the driver.
	236	*
	237	* This also computes 'to_set' which is the time we are trying to set, and has
	238	* a zero in tv_nsecs, such that:
	239	* to_set - set_delay_nsec == now +/- FUZZ
	240	*
	241	*/
	242	static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
	243	struct timespec64 *to_set,
	244	const struct timespec64 *now)
	245	{
	246	/* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
	247	const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
	248	struct timespec64 delay = {.tv_sec = 0,
	249	.tv_nsec = set_offset_nsec};
	250
	251	to_set = timespec64_add(now, delay);
	252
	253	if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
	254	to_set->tv_nsec = 0;
	255	return true;
	256	}
	257
	258	if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
	259	to_set->tv_sec++;
	260	to_set->tv_nsec = 0;
	261	return true;
	262	}
	263	return false;
	264	}
	265
3068a254 AB	266	#define rtc_register_device(device) \
	267	__rtc_register_device(THIS_MODULE, device)
	268
4c24e29e	269	#ifdef CONFIG_RTC_HCTOSYS_DEVICE
d0ab4a4d UKK	270	extern int rtc_hctosys_ret;
	271	#else
	272	#define rtc_hctosys_ret -ENODEV
	273	#endif
	274
1da177e4	275	#endif /* _LINUX_RTC_H_ */