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 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
71 ANDROID_KABI_RESERVE(1);
72 };
73
74 struct rtc_device;
75
76 struct rtc_timer {
77 struct timerqueue_node node;
78 ktime_t period;
79 void (*func)(struct rtc_device *rtc);
80 struct rtc_device *rtc;
81 int enabled;
82 };
83
84 /* flags */
85 #define RTC_DEV_BUSY 0
86
87 struct rtc_device {
88 struct device dev;
89 struct module *owner;
90
91 int id;
92
93 const struct rtc_class_ops *ops;
94 struct mutex ops_lock;
95
96 struct cdev char_dev;
97 unsigned long flags;
98
99 unsigned long irq_data;
100 spinlock_t irq_lock;
101 wait_queue_head_t irq_queue;
102 struct fasync_struct *async_queue;
103
104 int irq_freq;
105 int max_user_freq;
106
107 struct timerqueue_head timerqueue;
108 struct rtc_timer aie_timer;
109 struct rtc_timer uie_rtctimer;
110 struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
111 int pie_enabled;
112 struct work_struct irqwork;
113 /* Some hardware can't support UIE mode */
114 int uie_unsupported;
115
116 /*
117 * This offset specifies the update timing of the RTC.
118 *
119 * tsched t1 write(t2.tv_sec - 1sec)) t2 RTC increments seconds
120 *
121 * The offset defines how tsched is computed so that the write to
122 * the RTC (t2.tv_sec - 1sec) is correct versus the time required
123 * for the transport of the write and the time which the RTC needs
124 * to increment seconds the first time after the write (t2).
125 *
126 * For direct accessible RTCs tsched ~= t1 because the write time
127 * is negligible. For RTCs behind slow busses the transport time is
128 * significant and has to be taken into account.
129 *
130 * The time between the write (t1) and the first increment after
131 * the write (t2) is RTC specific. For a MC146818 RTC it's 500ms,
132 * for many others it's exactly 1 second. Consult the datasheet.
133 *
134 * The value of this offset is also used to calculate the to be
135 * written value (t2.tv_sec - 1sec) at tsched.
136 *
137 * The default value for this is NSEC_PER_SEC + 10 msec default
138 * transport time. The offset can be adjusted by drivers so the
139 * calculation for the to be written value at tsched becomes
140 * correct:
141 *
142 * newval = tsched + set_offset_nsec - NSEC_PER_SEC
143 * and (tsched + set_offset_nsec) % NSEC_PER_SEC == 0
144 */
145 unsigned long set_offset_nsec;
146
147 unsigned long features[BITS_TO_LONGS(RTC_FEATURE_CNT)];
148
149 time64_t range_min;
150 timeu64_t range_max;
151 time64_t start_secs;
152 time64_t offset_secs;
153 bool set_start_time;
154
155 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
156 struct work_struct uie_task;
157 struct timer_list uie_timer;
158 /* Those fields are protected by rtc->irq_lock */
159 unsigned int oldsecs;
160 unsigned int uie_irq_active:1;
161 unsigned int stop_uie_polling:1;
162 unsigned int uie_task_active:1;
163 unsigned int uie_timer_active:1;
164 #endif
165
166 ANDROID_KABI_RESERVE(1);
167 };
168 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
169
170 #define rtc_lock(d) mutex_lock(&d->ops_lock)
171 #define rtc_unlock(d) mutex_unlock(&d->ops_lock)
172
173 /* useful timestamps */
174 #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
175 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
176 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
177 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
178 #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */
179 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
180 #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
181 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
182
183 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
184 const char *name,
185 const struct rtc_class_ops *ops,
186 struct module *owner);
187 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
188 int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc);
189
190 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
191 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
192 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
193 extern int rtc_read_alarm(struct rtc_device *rtc,
194 struct rtc_wkalrm *alrm);
195 extern int rtc_set_alarm(struct rtc_device *rtc,
196 struct rtc_wkalrm *alrm);
197 extern int rtc_initialize_alarm(struct rtc_device *rtc,
198 struct rtc_wkalrm *alrm);
199 extern void rtc_update_irq(struct rtc_device *rtc,
200 unsigned long num, unsigned long events);
201
202 extern struct rtc_device *rtc_class_open(const char *name);
203 extern void rtc_class_close(struct rtc_device *rtc);
204
205 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
206 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
207 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
208 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
209 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
210 unsigned int enabled);
211
212 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
213 void rtc_aie_update_irq(struct rtc_device *rtc);
214 void rtc_uie_update_irq(struct rtc_device *rtc);
215 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
216
217 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
218 struct rtc_device *rtc);
219 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
220 ktime_t expires, ktime_t period);
221 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
222 int rtc_read_offset(struct rtc_device *rtc, long *offset);
223 int rtc_set_offset(struct rtc_device *rtc, long offset);
224 void rtc_timer_do_work(struct work_struct *work);
225
is_leap_year(unsigned int year)226 static inline bool is_leap_year(unsigned int year)
227 {
228 return (!(year % 4) && (year % 100)) || !(year % 400);
229 }
230
231 #define devm_rtc_register_device(device) \
232 __devm_rtc_register_device(THIS_MODULE, device)
233
234 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
235 extern int rtc_hctosys_ret;
236 #else
237 #define rtc_hctosys_ret -ENODEV
238 #endif
239
240 #ifdef CONFIG_RTC_NVMEM
241 int devm_rtc_nvmem_register(struct rtc_device *rtc,
242 struct nvmem_config *nvmem_config);
243 #else
devm_rtc_nvmem_register(struct rtc_device * rtc,struct nvmem_config * nvmem_config)244 static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
245 struct nvmem_config *nvmem_config)
246 {
247 return 0;
248 }
249 #endif
250
251 #ifdef CONFIG_RTC_INTF_SYSFS
252 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
253 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
254 #else
255 static inline
rtc_add_group(struct rtc_device * rtc,const struct attribute_group * grp)256 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
257 {
258 return 0;
259 }
260
261 static inline
rtc_add_groups(struct rtc_device * rtc,const struct attribute_group ** grps)262 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
263 {
264 return 0;
265 }
266 #endif
267 #endif /* _LINUX_RTC_H_ */
268