Merge tag 'riscv-for-linus-4.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-block.git] / include / linux / rtc.h
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b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
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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 *
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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 21extern int rtc_month_days(unsigned int month, unsigned int year);
8232212e 22extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
c58411e9 23extern int rtc_valid_tm(struct rtc_time *tm);
c2c11ae4 24extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
25extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
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26ktime_t rtc_tm_to_ktime(struct rtc_time tm);
27struct rtc_time rtc_ktime_to_tm(ktime_t kt);
28
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29/*
30 * rtc_tm_sub - Return the difference in seconds.
31 */
32static 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 37static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
38{
39 rtc_time64_to_tm(time, tm);
40}
41
c2c11ae4 42static 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
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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>
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54#include <linux/timerqueue.h>
55#include <linux/workqueue.h>
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56
57extern struct class *rtc_class;
58
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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()
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71 *
72 * REVISIT those periodic irq calls *do* have ops_lock when they're
73 * issued through ioctl() ...
74 */
0c86edc0 75struct rtc_class_ops {
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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);
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86 int (*read_offset)(struct device *, long *offset);
87 int (*set_offset)(struct device *, long offset);
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88};
89
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90typedef struct rtc_task {
91 void (*func)(void *private_data);
92 void *private_data;
93} rtc_task_t;
94
95
96struct rtc_timer {
97 struct rtc_task task;
98 struct timerqueue_node node;
99 ktime_t period;
100 int enabled;
101};
102
0c86edc0 103
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104/* flags */
105#define RTC_DEV_BUSY 0
106
1796dcce 107struct rtc_device {
cd966209 108 struct device dev;
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109 struct module *owner;
110
111 int id;
0c86edc0 112
ff8371ac 113 const struct rtc_class_ops *ops;
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114 struct mutex ops_lock;
115
0c86edc0 116 struct cdev char_dev;
8853c202 117 unsigned long flags;
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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;
110d693d 127 int max_user_freq;
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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;
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135 /* Some hardware can't support UIE mode */
136 int uie_unsupported;
6e57b1d6 137
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138 /* Number of nsec it takes to set the RTC clock. This influences when
139 * the set ops are called. An offset:
140 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
141 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
142 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
143 */
144 long set_offset_nsec;
145
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146 bool registered;
147
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148 struct nvmem_device *nvmem;
149 /* Old ABI support */
150 bool nvram_old_abi;
151 struct bin_attribute *nvram;
152
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153 time64_t range_min;
154 timeu64_t range_max;
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155 time64_t start_secs;
156 time64_t offset_secs;
157 bool set_start_time;
71db049e 158
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159#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
160 struct work_struct uie_task;
161 struct timer_list uie_timer;
162 /* Those fields are protected by rtc->irq_lock */
163 unsigned int oldsecs;
164 unsigned int uie_irq_active:1;
165 unsigned int stop_uie_polling:1;
166 unsigned int uie_task_active:1;
167 unsigned int uie_timer_active:1;
168#endif
0c86edc0 169};
cd966209 170#define to_rtc_device(d) container_of(d, struct rtc_device, dev)
0c86edc0 171
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172/* useful timestamps */
173#define RTC_TIMESTAMP_BEGIN_1900 -2208989361LL /* 1900-01-01 00:00:00 */
174#define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
175#define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
176
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177extern struct rtc_device *rtc_device_register(const char *name,
178 struct device *dev,
ff8371ac 179 const struct rtc_class_ops *ops,
0c86edc0 180 struct module *owner);
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181extern struct rtc_device *devm_rtc_device_register(struct device *dev,
182 const char *name,
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183 const struct rtc_class_ops *ops,
184 struct module *owner);
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185struct rtc_device *devm_rtc_allocate_device(struct device *dev);
186int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
ab6a2d70 187extern void rtc_device_unregister(struct rtc_device *rtc);
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188extern void devm_rtc_device_unregister(struct device *dev,
189 struct rtc_device *rtc);
0c86edc0 190
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191extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
192extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
0f295b06 193extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);
f44f7f96 194int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
ab6a2d70 195extern int rtc_read_alarm(struct rtc_device *rtc,
0c86edc0 196 struct rtc_wkalrm *alrm);
ab6a2d70 197extern int rtc_set_alarm(struct rtc_device *rtc,
0c86edc0 198 struct rtc_wkalrm *alrm);
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199extern int rtc_initialize_alarm(struct rtc_device *rtc,
200 struct rtc_wkalrm *alrm);
ab6a2d70 201extern void rtc_update_irq(struct rtc_device *rtc,
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202 unsigned long num, unsigned long events);
203
9f3b795a 204extern struct rtc_device *rtc_class_open(const char *name);
ab6a2d70 205extern void rtc_class_close(struct rtc_device *rtc);
0c86edc0 206
ab6a2d70 207extern int rtc_irq_register(struct rtc_device *rtc,
0c86edc0 208 struct rtc_task *task);
ab6a2d70 209extern void rtc_irq_unregister(struct rtc_device *rtc,
0c86edc0 210 struct rtc_task *task);
ab6a2d70 211extern int rtc_irq_set_state(struct rtc_device *rtc,
0c86edc0 212 struct rtc_task *task, int enabled);
ab6a2d70 213extern int rtc_irq_set_freq(struct rtc_device *rtc,
0c86edc0 214 struct rtc_task *task, int freq);
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215extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
216extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
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217extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
218 unsigned int enabled);
0c86edc0 219
456d66ec 220void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
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221void rtc_aie_update_irq(void *private);
222void rtc_uie_update_irq(void *private);
223enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
1da177e4 224
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225void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
226int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
227 ktime_t expires, ktime_t period);
73744a64 228void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
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229int rtc_read_offset(struct rtc_device *rtc, long *offset);
230int rtc_set_offset(struct rtc_device *rtc, long offset);
96c8f06a 231void rtc_timer_do_work(struct work_struct *work);
6610e089 232
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233static inline bool is_leap_year(unsigned int year)
234{
235 return (!(year % 4) && (year % 100)) || !(year % 400);
236}
237
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238/* Determine if we can call to driver to set the time. Drivers can only be
239 * called to set a second aligned time value, and the field set_offset_nsec
240 * specifies how far away from the second aligned time to call the driver.
241 *
242 * This also computes 'to_set' which is the time we are trying to set, and has
243 * a zero in tv_nsecs, such that:
244 * to_set - set_delay_nsec == now +/- FUZZ
245 *
246 */
247static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
248 struct timespec64 *to_set,
249 const struct timespec64 *now)
250{
251 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
252 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
253 struct timespec64 delay = {.tv_sec = 0,
254 .tv_nsec = set_offset_nsec};
255
256 *to_set = timespec64_add(*now, delay);
257
258 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
259 to_set->tv_nsec = 0;
260 return true;
261 }
262
263 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
264 to_set->tv_sec++;
265 to_set->tv_nsec = 0;
266 return true;
267 }
268 return false;
269}
270
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271#define rtc_register_device(device) \
272 __rtc_register_device(THIS_MODULE, device)
273
4c24e29e 274#ifdef CONFIG_RTC_HCTOSYS_DEVICE
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275extern int rtc_hctosys_ret;
276#else
277#define rtc_hctosys_ret -ENODEV
278#endif
279
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280#ifdef CONFIG_RTC_NVMEM
281int rtc_nvmem_register(struct rtc_device *rtc,
282 struct nvmem_config *nvmem_config);
283void rtc_nvmem_unregister(struct rtc_device *rtc);
284#else
285static inline int rtc_nvmem_register(struct rtc_device *rtc,
286 struct nvmem_config *nvmem_config)
287{
c59b3715 288 return 0;
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289}
290static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {}
291#endif
292
1da177e4 293#endif /* _LINUX_RTC_H_ */