xref: /openbmc/linux/include/linux/rtc.h (revision 612a462a)
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 <linux/nvmem-provider.h>
18 #include <uapi/linux/rtc.h>
19 
20 extern int rtc_month_days(unsigned int month, unsigned int year);
21 extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
22 extern int rtc_valid_tm(struct rtc_time *tm);
23 extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
24 extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
25 ktime_t rtc_tm_to_ktime(struct rtc_time tm);
26 struct rtc_time rtc_ktime_to_tm(ktime_t kt);
27 
28 /*
29  * rtc_tm_sub - Return the difference in seconds.
30  */
31 static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs)
32 {
33 	return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
34 }
35 
36 static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
37 {
38 	rtc_time64_to_tm(time, tm);
39 }
40 
41 static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
42 {
43 	*time = rtc_tm_to_time64(tm);
44 
45 	return 0;
46 }
47 
48 #include <linux/device.h>
49 #include <linux/seq_file.h>
50 #include <linux/cdev.h>
51 #include <linux/poll.h>
52 #include <linux/mutex.h>
53 #include <linux/timerqueue.h>
54 #include <linux/workqueue.h>
55 
56 extern struct class *rtc_class;
57 
58 /*
59  * For these RTC methods the device parameter is the physical device
60  * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
61  * was passed to rtc_device_register().  Its driver_data normally holds
62  * device state, including the rtc_device pointer for the RTC.
63  *
64  * Most of these methods are called with rtc_device.ops_lock held,
65  * through the rtc_*(struct rtc_device *, ...) calls.
66  *
67  * The (current) exceptions are mostly filesystem hooks:
68  *   - the proc() hook for procfs
69  *   - non-ioctl() chardev hooks:  open(), release(), read_callback()
70  *
71  * REVISIT those periodic irq calls *do* have ops_lock when they're
72  * issued through ioctl() ...
73  */
74 struct rtc_class_ops {
75 	int (*ioctl)(struct device *, unsigned int, unsigned long);
76 	int (*read_time)(struct device *, struct rtc_time *);
77 	int (*set_time)(struct device *, struct rtc_time *);
78 	int (*read_alarm)(struct device *, struct rtc_wkalrm *);
79 	int (*set_alarm)(struct device *, struct rtc_wkalrm *);
80 	int (*proc)(struct device *, struct seq_file *);
81 	int (*set_mmss64)(struct device *, time64_t secs);
82 	int (*set_mmss)(struct device *, unsigned long secs);
83 	int (*read_callback)(struct device *, int data);
84 	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
85 	int (*read_offset)(struct device *, long *offset);
86 	int (*set_offset)(struct device *, long offset);
87 };
88 
89 #define RTC_DEVICE_NAME_SIZE 20
90 typedef struct rtc_task {
91 	void (*func)(void *private_data);
92 	void *private_data;
93 } rtc_task_t;
94 
95 
96 struct rtc_timer {
97 	struct rtc_task	task;
98 	struct timerqueue_node node;
99 	ktime_t period;
100 	int enabled;
101 };
102 
103 
104 /* flags */
105 #define RTC_DEV_BUSY 0
106 
107 struct rtc_device {
108 	struct device dev;
109 	struct module *owner;
110 
111 	int id;
112 
113 	const struct rtc_class_ops *ops;
114 	struct mutex ops_lock;
115 
116 	struct cdev char_dev;
117 	unsigned long flags;
118 
119 	unsigned long irq_data;
120 	spinlock_t irq_lock;
121 	wait_queue_head_t irq_queue;
122 	struct fasync_struct *async_queue;
123 
124 	struct rtc_task *irq_task;
125 	spinlock_t irq_task_lock;
126 	int irq_freq;
127 	int max_user_freq;
128 
129 	struct timerqueue_head timerqueue;
130 	struct rtc_timer aie_timer;
131 	struct rtc_timer uie_rtctimer;
132 	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
133 	int pie_enabled;
134 	struct work_struct irqwork;
135 	/* Some hardware can't support UIE mode */
136 	int uie_unsupported;
137 
138 	bool registered;
139 
140 	struct nvmem_config *nvmem_config;
141 	struct nvmem_device *nvmem;
142 	/* Old ABI support */
143 	bool nvram_old_abi;
144 	struct bin_attribute *nvram;
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 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
168 int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
169 extern void rtc_device_unregister(struct rtc_device *rtc);
170 extern void devm_rtc_device_unregister(struct device *dev,
171 					struct rtc_device *rtc);
172 
173 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
174 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
175 extern int rtc_set_ntp_time(struct timespec64 now);
176 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
177 extern int rtc_read_alarm(struct rtc_device *rtc,
178 			struct rtc_wkalrm *alrm);
179 extern int rtc_set_alarm(struct rtc_device *rtc,
180 				struct rtc_wkalrm *alrm);
181 extern int rtc_initialize_alarm(struct rtc_device *rtc,
182 				struct rtc_wkalrm *alrm);
183 extern void rtc_update_irq(struct rtc_device *rtc,
184 			unsigned long num, unsigned long events);
185 
186 extern struct rtc_device *rtc_class_open(const char *name);
187 extern void rtc_class_close(struct rtc_device *rtc);
188 
189 extern int rtc_irq_register(struct rtc_device *rtc,
190 				struct rtc_task *task);
191 extern void rtc_irq_unregister(struct rtc_device *rtc,
192 				struct rtc_task *task);
193 extern int rtc_irq_set_state(struct rtc_device *rtc,
194 				struct rtc_task *task, int enabled);
195 extern int rtc_irq_set_freq(struct rtc_device *rtc,
196 				struct rtc_task *task, int freq);
197 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
198 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
199 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
200 						unsigned int enabled);
201 
202 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
203 void rtc_aie_update_irq(void *private);
204 void rtc_uie_update_irq(void *private);
205 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
206 
207 int rtc_register(rtc_task_t *task);
208 int rtc_unregister(rtc_task_t *task);
209 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
210 
211 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
212 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
213 		    ktime_t expires, ktime_t period);
214 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
215 int rtc_read_offset(struct rtc_device *rtc, long *offset);
216 int rtc_set_offset(struct rtc_device *rtc, long offset);
217 void rtc_timer_do_work(struct work_struct *work);
218 
219 static inline bool is_leap_year(unsigned int year)
220 {
221 	return (!(year % 4) && (year % 100)) || !(year % 400);
222 }
223 
224 #define rtc_register_device(device) \
225 	__rtc_register_device(THIS_MODULE, device)
226 
227 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
228 extern int rtc_hctosys_ret;
229 #else
230 #define rtc_hctosys_ret -ENODEV
231 #endif
232 
233 #endif /* _LINUX_RTC_H_ */
234