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 /* Number of nsec it takes to set the RTC clock. This influences when
117 * the set ops are called. An offset:
118 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
119 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
120 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
121 */
122 long set_offset_nsec;
123
124 bool registered;
125
126 /* Old ABI support */
127 bool nvram_old_abi;
128 struct bin_attribute *nvram;
129
130 time64_t range_min;
131 timeu64_t range_max;
132 time64_t start_secs;
133 time64_t offset_secs;
134 bool set_start_time;
135
136 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
137 struct work_struct uie_task;
138 struct timer_list uie_timer;
139 /* Those fields are protected by rtc->irq_lock */
140 unsigned int oldsecs;
141 unsigned int uie_irq_active:1;
142 unsigned int stop_uie_polling:1;
143 unsigned int uie_task_active:1;
144 unsigned int uie_timer_active:1;
145 #endif
146
147 ANDROID_KABI_RESERVE(1);
148 };
149 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
150
151 #define rtc_lock(d) mutex_lock(&d->ops_lock)
152 #define rtc_unlock(d) mutex_unlock(&d->ops_lock)
153
154 /* useful timestamps */
155 #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
156 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
157 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
158 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
159 #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */
160 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
161 #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
162 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
163
164 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
165 const char *name,
166 const struct rtc_class_ops *ops,
167 struct module *owner);
168 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
169 int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
170
171 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
172 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
173 extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);
174 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
175 extern int rtc_read_alarm(struct rtc_device *rtc,
176 struct rtc_wkalrm *alrm);
177 extern int rtc_set_alarm(struct rtc_device *rtc,
178 struct rtc_wkalrm *alrm);
179 extern int rtc_initialize_alarm(struct rtc_device *rtc,
180 struct rtc_wkalrm *alrm);
181 extern void rtc_update_irq(struct rtc_device *rtc,
182 unsigned long num, unsigned long events);
183
184 extern struct rtc_device *rtc_class_open(const char *name);
185 extern void rtc_class_close(struct rtc_device *rtc);
186
187 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
188 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
189 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
190 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
191 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
192 unsigned int enabled);
193
194 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
195 void rtc_aie_update_irq(struct rtc_device *rtc);
196 void rtc_uie_update_irq(struct rtc_device *rtc);
197 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
198
199 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
200 struct rtc_device *rtc);
201 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
202 ktime_t expires, ktime_t period);
203 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
204 int rtc_read_offset(struct rtc_device *rtc, long *offset);
205 int rtc_set_offset(struct rtc_device *rtc, long offset);
206 void rtc_timer_do_work(struct work_struct *work);
207
is_leap_year(unsigned int year)208 static inline bool is_leap_year(unsigned int year)
209 {
210 return (!(year % 4) && (year % 100)) || !(year % 400);
211 }
212
213 /* Determine if we can call to driver to set the time. Drivers can only be
214 * called to set a second aligned time value, and the field set_offset_nsec
215 * specifies how far away from the second aligned time to call the driver.
216 *
217 * This also computes 'to_set' which is the time we are trying to set, and has
218 * a zero in tv_nsecs, such that:
219 * to_set - set_delay_nsec == now +/- FUZZ
220 *
221 */
rtc_tv_nsec_ok(s64 set_offset_nsec,struct timespec64 * to_set,const struct timespec64 * now)222 static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
223 struct timespec64 *to_set,
224 const struct timespec64 *now)
225 {
226 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
227 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
228 struct timespec64 delay = {.tv_sec = 0,
229 .tv_nsec = set_offset_nsec};
230
231 *to_set = timespec64_add(*now, delay);
232
233 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
234 to_set->tv_nsec = 0;
235 return true;
236 }
237
238 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
239 to_set->tv_sec++;
240 to_set->tv_nsec = 0;
241 return true;
242 }
243 return false;
244 }
245
246 #define rtc_register_device(device) \
247 __rtc_register_device(THIS_MODULE, device)
248
249 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
250 extern int rtc_hctosys_ret;
251 #else
252 #define rtc_hctosys_ret -ENODEV
253 #endif
254
255 #ifdef CONFIG_RTC_NVMEM
256 int rtc_nvmem_register(struct rtc_device *rtc,
257 struct nvmem_config *nvmem_config);
258 void rtc_nvmem_unregister(struct rtc_device *rtc);
259 #else
rtc_nvmem_register(struct rtc_device * rtc,struct nvmem_config * nvmem_config)260 static inline int rtc_nvmem_register(struct rtc_device *rtc,
261 struct nvmem_config *nvmem_config)
262 {
263 return 0;
264 }
rtc_nvmem_unregister(struct rtc_device * rtc)265 static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {}
266 #endif
267
268 #ifdef CONFIG_RTC_INTF_SYSFS
269 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
270 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
271 #else
272 static inline
rtc_add_group(struct rtc_device * rtc,const struct attribute_group * grp)273 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
274 {
275 return 0;
276 }
277
278 static inline
rtc_add_groups(struct rtc_device * rtc,const struct attribute_group ** grps)279 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
280 {
281 return 0;
282 }
283 #endif
284 #endif /* _LINUX_RTC_H_ */
285