Line data Source code
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 : #include <linux/device.h>
38 : #include <linux/seq_file.h>
39 : #include <linux/cdev.h>
40 : #include <linux/poll.h>
41 : #include <linux/mutex.h>
42 : #include <linux/timerqueue.h>
43 : #include <linux/workqueue.h>
44 :
45 : extern struct class *rtc_class;
46 :
47 : /*
48 : * For these RTC methods the device parameter is the physical device
49 : * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
50 : * was passed to rtc_device_register(). Its driver_data normally holds
51 : * device state, including the rtc_device pointer for the RTC.
52 : *
53 : * Most of these methods are called with rtc_device.ops_lock held,
54 : * through the rtc_*(struct rtc_device *, ...) calls.
55 : *
56 : * The (current) exceptions are mostly filesystem hooks:
57 : * - the proc() hook for procfs
58 : */
59 : struct rtc_class_ops {
60 : int (*ioctl)(struct device *, unsigned int, unsigned long);
61 : int (*read_time)(struct device *, struct rtc_time *);
62 : int (*set_time)(struct device *, struct rtc_time *);
63 : int (*read_alarm)(struct device *, struct rtc_wkalrm *);
64 : int (*set_alarm)(struct device *, struct rtc_wkalrm *);
65 : int (*proc)(struct device *, struct seq_file *);
66 : int (*alarm_irq_enable)(struct device *, unsigned int enabled);
67 : int (*read_offset)(struct device *, long *offset);
68 : int (*set_offset)(struct device *, long offset);
69 : };
70 :
71 : struct rtc_device;
72 :
73 : struct rtc_timer {
74 : struct timerqueue_node node;
75 : ktime_t period;
76 : void (*func)(struct rtc_device *rtc);
77 : struct rtc_device *rtc;
78 : int enabled;
79 : };
80 :
81 : /* flags */
82 : #define RTC_DEV_BUSY 0
83 :
84 : struct rtc_device {
85 : struct device dev;
86 : struct module *owner;
87 :
88 : int id;
89 :
90 : const struct rtc_class_ops *ops;
91 : struct mutex ops_lock;
92 :
93 : struct cdev char_dev;
94 : unsigned long flags;
95 :
96 : unsigned long irq_data;
97 : spinlock_t irq_lock;
98 : wait_queue_head_t irq_queue;
99 : struct fasync_struct *async_queue;
100 :
101 : int irq_freq;
102 : int max_user_freq;
103 :
104 : struct timerqueue_head timerqueue;
105 : struct rtc_timer aie_timer;
106 : struct rtc_timer uie_rtctimer;
107 : struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
108 : int pie_enabled;
109 : struct work_struct irqwork;
110 : /* Some hardware can't support UIE mode */
111 : int uie_unsupported;
112 :
113 : /*
114 : * This offset specifies the update timing of the RTC.
115 : *
116 : * tsched t1 write(t2.tv_sec - 1sec)) t2 RTC increments seconds
117 : *
118 : * The offset defines how tsched is computed so that the write to
119 : * the RTC (t2.tv_sec - 1sec) is correct versus the time required
120 : * for the transport of the write and the time which the RTC needs
121 : * to increment seconds the first time after the write (t2).
122 : *
123 : * For direct accessible RTCs tsched ~= t1 because the write time
124 : * is negligible. For RTCs behind slow busses the transport time is
125 : * significant and has to be taken into account.
126 : *
127 : * The time between the write (t1) and the first increment after
128 : * the write (t2) is RTC specific. For a MC146818 RTC it's 500ms,
129 : * for many others it's exactly 1 second. Consult the datasheet.
130 : *
131 : * The value of this offset is also used to calculate the to be
132 : * written value (t2.tv_sec - 1sec) at tsched.
133 : *
134 : * The default value for this is NSEC_PER_SEC + 10 msec default
135 : * transport time. The offset can be adjusted by drivers so the
136 : * calculation for the to be written value at tsched becomes
137 : * correct:
138 : *
139 : * newval = tsched + set_offset_nsec - NSEC_PER_SEC
140 : * and (tsched + set_offset_nsec) % NSEC_PER_SEC == 0
141 : */
142 : unsigned long set_offset_nsec;
143 :
144 : unsigned long features[BITS_TO_LONGS(RTC_FEATURE_CNT)];
145 :
146 : time64_t range_min;
147 : timeu64_t range_max;
148 : time64_t start_secs;
149 : time64_t offset_secs;
150 : bool set_start_time;
151 :
152 : #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
153 : struct work_struct uie_task;
154 : struct timer_list uie_timer;
155 : /* Those fields are protected by rtc->irq_lock */
156 : unsigned int oldsecs;
157 : unsigned int uie_irq_active:1;
158 : unsigned int stop_uie_polling:1;
159 : unsigned int uie_task_active:1;
160 : unsigned int uie_timer_active:1;
161 : #endif
162 : };
163 : #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
164 :
165 : #define rtc_lock(d) mutex_lock(&d->ops_lock)
166 : #define rtc_unlock(d) mutex_unlock(&d->ops_lock)
167 :
168 : /* useful timestamps */
169 : #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
170 : #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
171 : #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
172 : #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
173 : #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */
174 : #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
175 : #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
176 : #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
177 :
178 : extern struct rtc_device *devm_rtc_device_register(struct device *dev,
179 : const char *name,
180 : const struct rtc_class_ops *ops,
181 : struct module *owner);
182 : struct rtc_device *devm_rtc_allocate_device(struct device *dev);
183 : int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc);
184 :
185 : extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
186 : extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
187 : int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
188 : extern int rtc_read_alarm(struct rtc_device *rtc,
189 : struct rtc_wkalrm *alrm);
190 : extern int rtc_set_alarm(struct rtc_device *rtc,
191 : struct rtc_wkalrm *alrm);
192 : extern int rtc_initialize_alarm(struct rtc_device *rtc,
193 : struct rtc_wkalrm *alrm);
194 : extern void rtc_update_irq(struct rtc_device *rtc,
195 : unsigned long num, unsigned long events);
196 :
197 : extern struct rtc_device *rtc_class_open(const char *name);
198 : extern void rtc_class_close(struct rtc_device *rtc);
199 :
200 : extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
201 : extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
202 : extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
203 : extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
204 : extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
205 : unsigned int enabled);
206 :
207 : void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
208 : void rtc_aie_update_irq(struct rtc_device *rtc);
209 : void rtc_uie_update_irq(struct rtc_device *rtc);
210 : enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
211 :
212 : void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
213 : struct rtc_device *rtc);
214 : int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
215 : ktime_t expires, ktime_t period);
216 : void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
217 : int rtc_read_offset(struct rtc_device *rtc, long *offset);
218 : int rtc_set_offset(struct rtc_device *rtc, long offset);
219 : void rtc_timer_do_work(struct work_struct *work);
220 :
221 0 : static inline bool is_leap_year(unsigned int year)
222 : {
223 0 : return (!(year % 4) && (year % 100)) || !(year % 400);
224 : }
225 :
226 : #define devm_rtc_register_device(device) \
227 : __devm_rtc_register_device(THIS_MODULE, device)
228 :
229 : #ifdef CONFIG_RTC_HCTOSYS_DEVICE
230 : extern int rtc_hctosys_ret;
231 : #else
232 : #define rtc_hctosys_ret -ENODEV
233 : #endif
234 :
235 : #ifdef CONFIG_RTC_NVMEM
236 : int devm_rtc_nvmem_register(struct rtc_device *rtc,
237 : struct nvmem_config *nvmem_config);
238 : #else
239 0 : static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
240 : struct nvmem_config *nvmem_config)
241 : {
242 0 : return 0;
243 : }
244 : #endif
245 :
246 : #ifdef CONFIG_RTC_INTF_SYSFS
247 : int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
248 : int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
249 : #else
250 : static inline
251 : int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
252 : {
253 : return 0;
254 : }
255 :
256 : static inline
257 : int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
258 : {
259 : return 0;
260 : }
261 : #endif
262 : #endif /* _LINUX_RTC_H_ */
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