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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 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>
6610e089
JS
54#include <linux/timerqueue.h>
55#include <linux/workqueue.h>
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56
57extern 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
ad5ea5b9 70 * - non-ioctl() chardev hooks: open(), release()
5ad31a57
DB
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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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 *);
099e6576 82 int (*alarm_irq_enable)(struct device *, unsigned int enabled);
b3967067
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83 int (*read_offset)(struct device *, long *offset);
84 int (*set_offset)(struct device *, long offset);
0c86edc0
AZ
85};
86
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87struct rtc_device;
88
6610e089 89struct rtc_timer {
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90 struct timerqueue_node node;
91 ktime_t period;
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92 void (*func)(struct rtc_device *rtc);
93 struct rtc_device *rtc;
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94 int enabled;
95};
96
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97/* flags */
98#define RTC_DEV_BUSY 0
99
1796dcce 100struct rtc_device {
cd966209 101 struct device dev;
0c86edc0
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102 struct module *owner;
103
104 int id;
0c86edc0 105
ff8371ac 106 const struct rtc_class_ops *ops;
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107 struct mutex ops_lock;
108
0c86edc0 109 struct cdev char_dev;
8853c202 110 unsigned long flags;
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111
112 unsigned long irq_data;
113 spinlock_t irq_lock;
114 wait_queue_head_t irq_queue;
115 struct fasync_struct *async_queue;
116
0c86edc0 117 int irq_freq;
110d693d 118 int max_user_freq;
6610e089
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119
120 struct timerqueue_head timerqueue;
121 struct rtc_timer aie_timer;
122 struct rtc_timer uie_rtctimer;
123 struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
124 int pie_enabled;
125 struct work_struct irqwork;
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126 /* Some hardware can't support UIE mode */
127 int uie_unsupported;
6e57b1d6 128
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JG
129 /* Number of nsec it takes to set the RTC clock. This influences when
130 * the set ops are called. An offset:
131 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
132 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
133 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
134 */
135 long set_offset_nsec;
136
3068a254
AB
137 bool registered;
138
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139 /* Old ABI support */
140 bool nvram_old_abi;
141 struct bin_attribute *nvram;
142
71db049e
AB
143 time64_t range_min;
144 timeu64_t range_max;
98951564
BW
145 time64_t start_secs;
146 time64_t offset_secs;
147 bool set_start_time;
71db049e 148
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JS
149#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
150 struct work_struct uie_task;
151 struct timer_list uie_timer;
152 /* Those fields are protected by rtc->irq_lock */
153 unsigned int oldsecs;
154 unsigned int uie_irq_active:1;
155 unsigned int stop_uie_polling:1;
156 unsigned int uie_task_active:1;
157 unsigned int uie_timer_active:1;
158#endif
0c86edc0 159};
cd966209 160#define to_rtc_device(d) container_of(d, struct rtc_device, dev)
0c86edc0 161
83bbc5ac 162/* useful timestamps */
f00eaa38 163#define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
d3062d1d 164#define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
83bbc5ac 165#define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
5ff404d1 166#define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
83bbc5ac 167#define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
8d6ac1ce 168#define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
beee05df 169#define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
83bbc5ac 170
6636a994
JH
171extern struct rtc_device *devm_rtc_device_register(struct device *dev,
172 const char *name,
3e217b66
JH
173 const struct rtc_class_ops *ops,
174 struct module *owner);
3068a254
AB
175struct rtc_device *devm_rtc_allocate_device(struct device *dev);
176int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
0c86edc0 177
ab6a2d70
DB
178extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
179extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
0f295b06 180extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);
f44f7f96 181int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
ab6a2d70 182extern int rtc_read_alarm(struct rtc_device *rtc,
0c86edc0 183 struct rtc_wkalrm *alrm);
ab6a2d70 184extern int rtc_set_alarm(struct rtc_device *rtc,
0c86edc0 185 struct rtc_wkalrm *alrm);
f6d5b331
JS
186extern int rtc_initialize_alarm(struct rtc_device *rtc,
187 struct rtc_wkalrm *alrm);
ab6a2d70 188extern void rtc_update_irq(struct rtc_device *rtc,
0c86edc0
AZ
189 unsigned long num, unsigned long events);
190
9f3b795a 191extern struct rtc_device *rtc_class_open(const char *name);
ab6a2d70 192extern void rtc_class_close(struct rtc_device *rtc);
0c86edc0 193
8719d3c9
AB
194extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
195extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
099e6576
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196extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
197extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
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198extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
199 unsigned int enabled);
0c86edc0 200
456d66ec 201void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
9a032011
AB
202void rtc_aie_update_irq(struct rtc_device *rtc);
203void rtc_uie_update_irq(struct rtc_device *rtc);
6610e089 204enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
1da177e4 205
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206void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
207 struct rtc_device *rtc);
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208int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
209 ktime_t expires, ktime_t period);
73744a64 210void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
b3967067
JC
211int rtc_read_offset(struct rtc_device *rtc, long *offset);
212int rtc_set_offset(struct rtc_device *rtc, long offset);
96c8f06a 213void rtc_timer_do_work(struct work_struct *work);
6610e089 214
78d89ef4
AM
215static inline bool is_leap_year(unsigned int year)
216{
217 return (!(year % 4) && (year % 100)) || !(year % 400);
218}
219
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JG
220/* Determine if we can call to driver to set the time. Drivers can only be
221 * called to set a second aligned time value, and the field set_offset_nsec
222 * specifies how far away from the second aligned time to call the driver.
223 *
224 * This also computes 'to_set' which is the time we are trying to set, and has
225 * a zero in tv_nsecs, such that:
226 * to_set - set_delay_nsec == now +/- FUZZ
227 *
228 */
229static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
230 struct timespec64 *to_set,
231 const struct timespec64 *now)
232{
233 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
234 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
235 struct timespec64 delay = {.tv_sec = 0,
236 .tv_nsec = set_offset_nsec};
237
238 *to_set = timespec64_add(*now, delay);
239
240 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
241 to_set->tv_nsec = 0;
242 return true;
243 }
244
245 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
246 to_set->tv_sec++;
247 to_set->tv_nsec = 0;
248 return true;
249 }
250 return false;
251}
252
3068a254
AB
253#define rtc_register_device(device) \
254 __rtc_register_device(THIS_MODULE, device)
255
4c24e29e 256#ifdef CONFIG_RTC_HCTOSYS_DEVICE
d0ab4a4d
UKK
257extern int rtc_hctosys_ret;
258#else
259#define rtc_hctosys_ret -ENODEV
260#endif
261
fd5cd21d
AB
262#ifdef CONFIG_RTC_NVMEM
263int rtc_nvmem_register(struct rtc_device *rtc,
264 struct nvmem_config *nvmem_config);
265void rtc_nvmem_unregister(struct rtc_device *rtc);
266#else
267static inline int rtc_nvmem_register(struct rtc_device *rtc,
268 struct nvmem_config *nvmem_config)
269{
c59b3715 270 return 0;
fd5cd21d
AB
271}
272static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {}
273#endif
274
eb2bccb7
AB
275#ifdef CONFIG_RTC_INTF_SYSFS
276int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
277int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
278#else
279static inline
280int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
281{
282 return 0;
283}
284
285static inline
286int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
287{
288 return 0;
289}
290#endif
1da177e4 291#endif /* _LINUX_RTC_H_ */