xref: /openbmc/linux/include/linux/rtc.h (revision bb970707)
1 /*
2  * Generic RTC interface.
3  * This version contains the part of the user interface to the Real Time Clock
4  * service. It is used with both the legacy mc146818 and also  EFI
5  * Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
6  * from <linux/mc146818rtc.h> to this file for 2.4 kernels.
7  *
8  * Copyright (C) 1999 Hewlett-Packard Co.
9  * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
10  */
11 #ifndef _LINUX_RTC_H_
12 #define _LINUX_RTC_H_
13 
14 
15 #include <linux/types.h>
16 #include <linux/interrupt.h>
17 #include <uapi/linux/rtc.h>
18 
19 extern int rtc_month_days(unsigned int month, unsigned int year);
20 extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
21 extern int rtc_valid_tm(struct rtc_time *tm);
22 extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
23 extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
24 ktime_t rtc_tm_to_ktime(struct rtc_time tm);
25 struct rtc_time rtc_ktime_to_tm(ktime_t kt);
26 
27 /*
28  * rtc_tm_sub - Return the difference in seconds.
29  */
30 static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs)
31 {
32 	return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
33 }
34 
35 /**
36  * Deprecated. Use rtc_time64_to_tm().
37  */
38 static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
39 {
40 	rtc_time64_to_tm(time, tm);
41 }
42 
43 /**
44  * Deprecated. Use rtc_tm_to_time64().
45  */
46 static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
47 {
48 	*time = rtc_tm_to_time64(tm);
49 
50 	return 0;
51 }
52 
53 #include <linux/device.h>
54 #include <linux/seq_file.h>
55 #include <linux/cdev.h>
56 #include <linux/poll.h>
57 #include <linux/mutex.h>
58 #include <linux/timerqueue.h>
59 #include <linux/workqueue.h>
60 
61 extern struct class *rtc_class;
62 
63 /*
64  * For these RTC methods the device parameter is the physical device
65  * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
66  * was passed to rtc_device_register().  Its driver_data normally holds
67  * device state, including the rtc_device pointer for the RTC.
68  *
69  * Most of these methods are called with rtc_device.ops_lock held,
70  * through the rtc_*(struct rtc_device *, ...) calls.
71  *
72  * The (current) exceptions are mostly filesystem hooks:
73  *   - the proc() hook for procfs
74  *   - non-ioctl() chardev hooks:  open(), release(), read_callback()
75  *
76  * REVISIT those periodic irq calls *do* have ops_lock when they're
77  * issued through ioctl() ...
78  */
79 struct rtc_class_ops {
80 	int (*open)(struct device *);
81 	void (*release)(struct device *);
82 	int (*ioctl)(struct device *, unsigned int, unsigned long);
83 	int (*read_time)(struct device *, struct rtc_time *);
84 	int (*set_time)(struct device *, struct rtc_time *);
85 	int (*read_alarm)(struct device *, struct rtc_wkalrm *);
86 	int (*set_alarm)(struct device *, struct rtc_wkalrm *);
87 	int (*proc)(struct device *, struct seq_file *);
88 	int (*set_mmss64)(struct device *, time64_t secs);
89 	int (*set_mmss)(struct device *, unsigned long secs);
90 	int (*read_callback)(struct device *, int data);
91 	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
92 	int (*read_offset)(struct device *, long *offset);
93 	int (*set_offset)(struct device *, long offset);
94 };
95 
96 #define RTC_DEVICE_NAME_SIZE 20
97 typedef struct rtc_task {
98 	void (*func)(void *private_data);
99 	void *private_data;
100 } rtc_task_t;
101 
102 
103 struct rtc_timer {
104 	struct rtc_task	task;
105 	struct timerqueue_node node;
106 	ktime_t period;
107 	int enabled;
108 };
109 
110 
111 /* flags */
112 #define RTC_DEV_BUSY 0
113 
114 struct rtc_device {
115 	struct device dev;
116 	struct module *owner;
117 
118 	int id;
119 	char name[RTC_DEVICE_NAME_SIZE];
120 
121 	const struct rtc_class_ops *ops;
122 	struct mutex ops_lock;
123 
124 	struct cdev char_dev;
125 	unsigned long flags;
126 
127 	unsigned long irq_data;
128 	spinlock_t irq_lock;
129 	wait_queue_head_t irq_queue;
130 	struct fasync_struct *async_queue;
131 
132 	struct rtc_task *irq_task;
133 	spinlock_t irq_task_lock;
134 	int irq_freq;
135 	int max_user_freq;
136 
137 	struct timerqueue_head timerqueue;
138 	struct rtc_timer aie_timer;
139 	struct rtc_timer uie_rtctimer;
140 	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
141 	int pie_enabled;
142 	struct work_struct irqwork;
143 	/* Some hardware can't support UIE mode */
144 	int uie_unsupported;
145 
146 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
147 	struct work_struct uie_task;
148 	struct timer_list uie_timer;
149 	/* Those fields are protected by rtc->irq_lock */
150 	unsigned int oldsecs;
151 	unsigned int uie_irq_active:1;
152 	unsigned int stop_uie_polling:1;
153 	unsigned int uie_task_active:1;
154 	unsigned int uie_timer_active:1;
155 #endif
156 };
157 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
158 
159 extern struct rtc_device *rtc_device_register(const char *name,
160 					struct device *dev,
161 					const struct rtc_class_ops *ops,
162 					struct module *owner);
163 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
164 					const char *name,
165 					const struct rtc_class_ops *ops,
166 					struct module *owner);
167 extern void rtc_device_unregister(struct rtc_device *rtc);
168 extern void devm_rtc_device_unregister(struct device *dev,
169 					struct rtc_device *rtc);
170 
171 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
172 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
173 extern int rtc_set_ntp_time(struct timespec64 now);
174 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
175 extern int rtc_read_alarm(struct rtc_device *rtc,
176 			struct rtc_wkalrm *alrm);
177 extern int rtc_set_alarm(struct rtc_device *rtc,
178 				struct rtc_wkalrm *alrm);
179 extern int rtc_initialize_alarm(struct rtc_device *rtc,
180 				struct rtc_wkalrm *alrm);
181 extern void rtc_update_irq(struct rtc_device *rtc,
182 			unsigned long num, unsigned long events);
183 
184 extern struct rtc_device *rtc_class_open(const char *name);
185 extern void rtc_class_close(struct rtc_device *rtc);
186 
187 extern int rtc_irq_register(struct rtc_device *rtc,
188 				struct rtc_task *task);
189 extern void rtc_irq_unregister(struct rtc_device *rtc,
190 				struct rtc_task *task);
191 extern int rtc_irq_set_state(struct rtc_device *rtc,
192 				struct rtc_task *task, int enabled);
193 extern int rtc_irq_set_freq(struct rtc_device *rtc,
194 				struct rtc_task *task, int freq);
195 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
196 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
197 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
198 						unsigned int enabled);
199 
200 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
201 void rtc_aie_update_irq(void *private);
202 void rtc_uie_update_irq(void *private);
203 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
204 
205 int rtc_register(rtc_task_t *task);
206 int rtc_unregister(rtc_task_t *task);
207 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
208 
209 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
210 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
211 		    ktime_t expires, ktime_t period);
212 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
213 int rtc_read_offset(struct rtc_device *rtc, long *offset);
214 int rtc_set_offset(struct rtc_device *rtc, long offset);
215 void rtc_timer_do_work(struct work_struct *work);
216 
217 static inline bool is_leap_year(unsigned int year)
218 {
219 	return (!(year % 4) && (year % 100)) || !(year % 400);
220 }
221 
222 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
223 extern int rtc_hctosys_ret;
224 #else
225 #define rtc_hctosys_ret -ENODEV
226 #endif
227 
228 #endif /* _LINUX_RTC_H_ */
229