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 */
rtc_tm_sub(struct rtc_time * lhs,struct rtc_time * rhs)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
is_leap_year(unsigned int year)221 static inline bool is_leap_year(unsigned int year)
222 {
223 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
devm_rtc_nvmem_register(struct rtc_device * rtc,struct nvmem_config * nvmem_config)239 static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
240 struct nvmem_config *nvmem_config)
241 {
242 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
rtc_add_group(struct rtc_device * rtc,const struct attribute_group * grp)251 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
252 {
253 return 0;
254 }
255
256 static inline
rtc_add_groups(struct rtc_device * rtc,const struct attribute_group ** grps)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_ */
263
