xref: /openbmc/linux/include/linux/rtc.h (revision b2441318)
1 /* SPDX-License-Identifier: GPL-2.0 */
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.
8  *
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 
15 
16 #include <linux/types.h>
17 #include <linux/interrupt.h>
18 #include <linux/nvmem-provider.h>
19 #include <uapi/linux/rtc.h>
20 
21 extern int rtc_month_days(unsigned int month, unsigned int year);
22 extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
23 extern int rtc_valid_tm(struct rtc_time *tm);
24 extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
25 extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
26 ktime_t rtc_tm_to_ktime(struct rtc_time tm);
27 struct rtc_time rtc_ktime_to_tm(ktime_t kt);
28 
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 
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 
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 }
48 
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>
54 #include <linux/timerqueue.h>
55 #include <linux/workqueue.h>
56 
57 extern struct class *rtc_class;
58 
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()
71  *
72  * REVISIT those periodic irq calls *do* have ops_lock when they're
73  * issued through ioctl() ...
74  */
75 struct rtc_class_ops {
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 *);
82 	int (*set_mmss64)(struct device *, time64_t secs);
83 	int (*set_mmss)(struct device *, unsigned long secs);
84 	int (*read_callback)(struct device *, int data);
85 	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
86 	int (*read_offset)(struct device *, long *offset);
87 	int (*set_offset)(struct device *, long offset);
88 };
89 
90 #define RTC_DEVICE_NAME_SIZE 20
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 
104 
105 /* flags */
106 #define RTC_DEV_BUSY 0
107 
108 struct rtc_device {
109 	struct device dev;
110 	struct module *owner;
111 
112 	int id;
113 
114 	const struct rtc_class_ops *ops;
115 	struct mutex ops_lock;
116 
117 	struct cdev char_dev;
118 	unsigned long flags;
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;
128 	int max_user_freq;
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;
136 	/* Some hardware can't support UIE mode */
137 	int uie_unsupported;
138 
139 	bool registered;
140 
141 	struct nvmem_config *nvmem_config;
142 	struct nvmem_device *nvmem;
143 	/* Old ABI support */
144 	bool nvram_old_abi;
145 	struct bin_attribute *nvram;
146 
147 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
148 	struct work_struct uie_task;
149 	struct timer_list uie_timer;
150 	/* Those fields are protected by rtc->irq_lock */
151 	unsigned int oldsecs;
152 	unsigned int uie_irq_active:1;
153 	unsigned int stop_uie_polling:1;
154 	unsigned int uie_task_active:1;
155 	unsigned int uie_timer_active:1;
156 #endif
157 };
158 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
159 
160 extern struct rtc_device *rtc_device_register(const char *name,
161 					struct device *dev,
162 					const struct rtc_class_ops *ops,
163 					struct module *owner);
164 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
165 					const char *name,
166 					const struct rtc_class_ops *ops,
167 					struct module *owner);
168 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
169 int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
170 extern void rtc_device_unregister(struct rtc_device *rtc);
171 extern void devm_rtc_device_unregister(struct device *dev,
172 					struct rtc_device *rtc);
173 
174 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
175 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
176 extern int rtc_set_ntp_time(struct timespec64 now);
177 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
178 extern int rtc_read_alarm(struct rtc_device *rtc,
179 			struct rtc_wkalrm *alrm);
180 extern int rtc_set_alarm(struct rtc_device *rtc,
181 				struct rtc_wkalrm *alrm);
182 extern int rtc_initialize_alarm(struct rtc_device *rtc,
183 				struct rtc_wkalrm *alrm);
184 extern void rtc_update_irq(struct rtc_device *rtc,
185 			unsigned long num, unsigned long events);
186 
187 extern struct rtc_device *rtc_class_open(const char *name);
188 extern void rtc_class_close(struct rtc_device *rtc);
189 
190 extern int rtc_irq_register(struct rtc_device *rtc,
191 				struct rtc_task *task);
192 extern void rtc_irq_unregister(struct rtc_device *rtc,
193 				struct rtc_task *task);
194 extern int rtc_irq_set_state(struct rtc_device *rtc,
195 				struct rtc_task *task, int enabled);
196 extern int rtc_irq_set_freq(struct rtc_device *rtc,
197 				struct rtc_task *task, int freq);
198 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
199 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
200 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
201 						unsigned int enabled);
202 
203 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
204 void rtc_aie_update_irq(void *private);
205 void rtc_uie_update_irq(void *private);
206 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
207 
208 int rtc_register(rtc_task_t *task);
209 int rtc_unregister(rtc_task_t *task);
210 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
211 
212 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
213 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
214 		    ktime_t expires, ktime_t period);
215 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
216 int rtc_read_offset(struct rtc_device *rtc, long *offset);
217 int rtc_set_offset(struct rtc_device *rtc, long offset);
218 void rtc_timer_do_work(struct work_struct *work);
219 
220 static inline bool is_leap_year(unsigned int year)
221 {
222 	return (!(year % 4) && (year % 100)) || !(year % 400);
223 }
224 
225 #define rtc_register_device(device) \
226 	__rtc_register_device(THIS_MODULE, device)
227 
228 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
229 extern int rtc_hctosys_ret;
230 #else
231 #define rtc_hctosys_ret -ENODEV
232 #endif
233 
234 #endif /* _LINUX_RTC_H_ */
235