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 <linux/android_kabi.h>
20 #include <uapi/linux/rtc.h>
21
22 extern int rtc_month_days(unsigned int month, unsigned int year);
23 extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
24 extern int rtc_valid_tm(struct rtc_time *tm);
25 extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
26 extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
27 ktime_t rtc_tm_to_ktime(struct rtc_time tm);
28 struct rtc_time rtc_ktime_to_tm(ktime_t kt);
29
30 /*
31 * rtc_tm_sub - Return the difference in seconds.
32 */
rtc_tm_sub(struct rtc_time * lhs,struct rtc_time * rhs)33 static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs)
34 {
35 return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
36 }
37
38 #include <linux/device.h>
39 #include <linux/seq_file.h>
40 #include <linux/cdev.h>
41 #include <linux/poll.h>
42 #include <linux/mutex.h>
43 #include <linux/timerqueue.h>
44 #include <linux/workqueue.h>
45
46 extern const struct class rtc_class;
47
48 /*
49 * For these RTC methods the device parameter is the physical device
50 * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
51 * was passed to rtc_device_register(). Its driver_data normally holds
52 * device state, including the rtc_device pointer for the RTC.
53 *
54 * Most of these methods are called with rtc_device.ops_lock held,
55 * through the rtc_*(struct rtc_device *, ...) calls.
56 *
57 * The (current) exceptions are mostly filesystem hooks:
58 * - the proc() hook for procfs
59 */
60 struct rtc_class_ops {
61 int (*ioctl)(struct device *, unsigned int, unsigned long);
62 int (*read_time)(struct device *, struct rtc_time *);
63 int (*set_time)(struct device *, struct rtc_time *);
64 int (*read_alarm)(struct device *, struct rtc_wkalrm *);
65 int (*set_alarm)(struct device *, struct rtc_wkalrm *);
66 int (*proc)(struct device *, struct seq_file *);
67 int (*alarm_irq_enable)(struct device *, unsigned int enabled);
68 int (*read_offset)(struct device *, long *offset);
69 int (*set_offset)(struct device *, long offset);
70 int (*param_get)(struct device *, struct rtc_param *param);
71 int (*param_set)(struct device *, struct rtc_param *param);
72
73 ANDROID_KABI_RESERVE(1);
74 };
75
76 struct rtc_device;
77
78 struct rtc_timer {
79 struct timerqueue_node node;
80 ktime_t period;
81 void (*func)(struct rtc_device *rtc);
82 struct rtc_device *rtc;
83 int enabled;
84 };
85
86 /* flags */
87 #define RTC_DEV_BUSY 0
88 #define RTC_NO_CDEV 1
89
90 struct rtc_device {
91 struct device dev;
92 struct module *owner;
93
94 int id;
95
96 const struct rtc_class_ops *ops;
97 struct mutex ops_lock;
98
99 struct cdev char_dev;
100 unsigned long flags;
101
102 unsigned long irq_data;
103 spinlock_t irq_lock;
104 wait_queue_head_t irq_queue;
105 struct fasync_struct *async_queue;
106
107 int irq_freq;
108 int max_user_freq;
109
110 struct timerqueue_head timerqueue;
111 struct rtc_timer aie_timer;
112 struct rtc_timer uie_rtctimer;
113 struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
114 int pie_enabled;
115 struct work_struct irqwork;
116
117 /*
118 * This offset specifies the update timing of the RTC.
119 *
120 * tsched t1 write(t2.tv_sec - 1sec)) t2 RTC increments seconds
121 *
122 * The offset defines how tsched is computed so that the write to
123 * the RTC (t2.tv_sec - 1sec) is correct versus the time required
124 * for the transport of the write and the time which the RTC needs
125 * to increment seconds the first time after the write (t2).
126 *
127 * For direct accessible RTCs tsched ~= t1 because the write time
128 * is negligible. For RTCs behind slow busses the transport time is
129 * significant and has to be taken into account.
130 *
131 * The time between the write (t1) and the first increment after
132 * the write (t2) is RTC specific. For a MC146818 RTC it's 500ms,
133 * for many others it's exactly 1 second. Consult the datasheet.
134 *
135 * The value of this offset is also used to calculate the to be
136 * written value (t2.tv_sec - 1sec) at tsched.
137 *
138 * The default value for this is NSEC_PER_SEC + 10 msec default
139 * transport time. The offset can be adjusted by drivers so the
140 * calculation for the to be written value at tsched becomes
141 * correct:
142 *
143 * newval = tsched + set_offset_nsec - NSEC_PER_SEC
144 * and (tsched + set_offset_nsec) % NSEC_PER_SEC == 0
145 */
146 unsigned long set_offset_nsec;
147
148 unsigned long features[BITS_TO_LONGS(RTC_FEATURE_CNT)];
149
150 time64_t range_min;
151 timeu64_t range_max;
152 timeu64_t alarm_offset_max;
153 time64_t start_secs;
154 time64_t offset_secs;
155 bool set_start_time;
156
157 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
158 struct work_struct uie_task;
159 struct timer_list uie_timer;
160 /* Those fields are protected by rtc->irq_lock */
161 unsigned int oldsecs;
162 unsigned int uie_irq_active:1;
163 unsigned int stop_uie_polling:1;
164 unsigned int uie_task_active:1;
165 unsigned int uie_timer_active:1;
166 #endif
167
168 ANDROID_KABI_RESERVE(1);
169 };
170 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
171
172 #define rtc_lock(d) mutex_lock(&d->ops_lock)
173 #define rtc_unlock(d) mutex_unlock(&d->ops_lock)
174
175 /* useful timestamps */
176 #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
177 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
178 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
179 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
180 #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */
181 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
182 #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
183 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
184
185 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
186 const char *name,
187 const struct rtc_class_ops *ops,
188 struct module *owner);
189 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
190 int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc);
191
192 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
193 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
194 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
195 extern int rtc_read_alarm(struct rtc_device *rtc,
196 struct rtc_wkalrm *alrm);
197 extern int rtc_set_alarm(struct rtc_device *rtc,
198 struct rtc_wkalrm *alrm);
199 extern int rtc_initialize_alarm(struct rtc_device *rtc,
200 struct rtc_wkalrm *alrm);
201 extern void rtc_update_irq(struct rtc_device *rtc,
202 unsigned long num, unsigned long events);
203
204 extern struct rtc_device *rtc_class_open(const char *name);
205 extern void rtc_class_close(struct rtc_device *rtc);
206
207 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
208 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
209 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
210 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
211 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
212 unsigned int enabled);
213
214 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
215 void rtc_aie_update_irq(struct rtc_device *rtc);
216 void rtc_uie_update_irq(struct rtc_device *rtc);
217 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
218
219 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
220 struct rtc_device *rtc);
221 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
222 ktime_t expires, ktime_t period);
223 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
224 int rtc_read_offset(struct rtc_device *rtc, long *offset);
225 int rtc_set_offset(struct rtc_device *rtc, long offset);
226 void rtc_timer_do_work(struct work_struct *work);
227
is_leap_year(unsigned int year)228 static inline bool is_leap_year(unsigned int year)
229 {
230 return (!(year % 4) && (year % 100)) || !(year % 400);
231 }
232
233 /**
234 * rtc_bound_alarmtime() - Return alarm time bound by rtc limit
235 * @rtc: Pointer to rtc device structure
236 * @requested: Requested alarm timeout
237 *
238 * Return: Alarm timeout bound by maximum alarm time supported by rtc.
239 */
rtc_bound_alarmtime(struct rtc_device * rtc,ktime_t requested)240 static inline ktime_t rtc_bound_alarmtime(struct rtc_device *rtc,
241 ktime_t requested)
242 {
243 if (rtc->alarm_offset_max &&
244 rtc->alarm_offset_max * MSEC_PER_SEC < ktime_to_ms(requested))
245 return ms_to_ktime(rtc->alarm_offset_max * MSEC_PER_SEC);
246
247 return requested;
248 }
249
250 #define devm_rtc_register_device(device) \
251 __devm_rtc_register_device(THIS_MODULE, device)
252
253 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
254 extern int rtc_hctosys_ret;
255 #else
256 #define rtc_hctosys_ret -ENODEV
257 #endif
258
259 #ifdef CONFIG_RTC_NVMEM
260 int devm_rtc_nvmem_register(struct rtc_device *rtc,
261 struct nvmem_config *nvmem_config);
262 #else
devm_rtc_nvmem_register(struct rtc_device * rtc,struct nvmem_config * nvmem_config)263 static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
264 struct nvmem_config *nvmem_config)
265 {
266 return 0;
267 }
268 #endif
269
270 #ifdef CONFIG_RTC_INTF_SYSFS
271 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
272 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
273 #else
274 static inline
rtc_add_group(struct rtc_device * rtc,const struct attribute_group * grp)275 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
276 {
277 return 0;
278 }
279
280 static inline
rtc_add_groups(struct rtc_device * rtc,const struct attribute_group ** grps)281 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
282 {
283 return 0;
284 }
285 #endif
286 #endif /* _LINUX_RTC_H_ */
287