1 /* SPDX-License-Identifier: GPL-2.0 */
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.
9 * Copyright (C) 1999 Hewlett-Packard Co.
10 * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
16 #include <linux/types.h>
17 #include <linux/interrupt.h>
18 #include <linux/nvmem-provider.h>
19 #include <uapi/linux/rtc.h>
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);
30 * rtc_tm_sub - Return the difference in seconds.
32 static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs)
34 return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
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>
45 extern struct class *rtc_class;
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.
53 * Most of these methods are called with rtc_device.ops_lock held,
54 * through the rtc_*(struct rtc_device *, ...) calls.
56 * The (current) exceptions are mostly filesystem hooks:
57 * - the proc() hook for procfs
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);
74 struct timerqueue_node node;
76 void (*func)(struct rtc_device *rtc);
77 struct rtc_device *rtc;
82 #define RTC_DEV_BUSY 0
90 const struct rtc_class_ops *ops;
91 struct mutex ops_lock;
96 unsigned long irq_data;
98 wait_queue_head_t irq_queue;
99 struct fasync_struct *async_queue;
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 */
109 struct work_struct irqwork;
110 /* Some hardware can't support UIE mode */
113 /* Number of nsec it takes to set the RTC clock. This influences when
114 * the set ops are called. An offset:
115 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s
116 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s
117 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s
119 long set_offset_nsec;
126 time64_t offset_secs;
129 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
130 struct work_struct uie_task;
131 struct timer_list uie_timer;
132 /* Those fields are protected by rtc->irq_lock */
133 unsigned int oldsecs;
134 unsigned int uie_irq_active:1;
135 unsigned int stop_uie_polling:1;
136 unsigned int uie_task_active:1;
137 unsigned int uie_timer_active:1;
140 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
142 #define rtc_lock(d) mutex_lock(&d->ops_lock)
143 #define rtc_unlock(d) mutex_unlock(&d->ops_lock)
145 /* useful timestamps */
146 #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */
147 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */
148 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */
149 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */
150 #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */
151 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */
152 #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */
153 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */
155 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
157 const struct rtc_class_ops *ops,
158 struct module *owner);
159 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
160 int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
162 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
163 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
164 extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec);
165 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
166 extern int rtc_read_alarm(struct rtc_device *rtc,
167 struct rtc_wkalrm *alrm);
168 extern int rtc_set_alarm(struct rtc_device *rtc,
169 struct rtc_wkalrm *alrm);
170 extern int rtc_initialize_alarm(struct rtc_device *rtc,
171 struct rtc_wkalrm *alrm);
172 extern void rtc_update_irq(struct rtc_device *rtc,
173 unsigned long num, unsigned long events);
175 extern struct rtc_device *rtc_class_open(const char *name);
176 extern void rtc_class_close(struct rtc_device *rtc);
178 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);
179 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);
180 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
181 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
182 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
183 unsigned int enabled);
185 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
186 void rtc_aie_update_irq(struct rtc_device *rtc);
187 void rtc_uie_update_irq(struct rtc_device *rtc);
188 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
190 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
191 struct rtc_device *rtc);
192 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
193 ktime_t expires, ktime_t period);
194 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
195 int rtc_read_offset(struct rtc_device *rtc, long *offset);
196 int rtc_set_offset(struct rtc_device *rtc, long offset);
197 void rtc_timer_do_work(struct work_struct *work);
199 static inline bool is_leap_year(unsigned int year)
201 return (!(year % 4) && (year % 100)) || !(year % 400);
204 /* Determine if we can call to driver to set the time. Drivers can only be
205 * called to set a second aligned time value, and the field set_offset_nsec
206 * specifies how far away from the second aligned time to call the driver.
208 * This also computes 'to_set' which is the time we are trying to set, and has
209 * a zero in tv_nsecs, such that:
210 * to_set - set_delay_nsec == now +/- FUZZ
213 static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec,
214 struct timespec64 *to_set,
215 const struct timespec64 *now)
217 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */
218 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5;
219 struct timespec64 delay = {.tv_sec = 0,
220 .tv_nsec = set_offset_nsec};
222 *to_set = timespec64_add(*now, delay);
224 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) {
229 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) {
237 #define rtc_register_device(device) \
238 __rtc_register_device(THIS_MODULE, device)
240 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
241 extern int rtc_hctosys_ret;
243 #define rtc_hctosys_ret -ENODEV
246 #ifdef CONFIG_RTC_NVMEM
247 int devm_rtc_nvmem_register(struct rtc_device *rtc,
248 struct nvmem_config *nvmem_config);
250 static inline int devm_rtc_nvmem_register(struct rtc_device *rtc,
251 struct nvmem_config *nvmem_config)
257 #ifdef CONFIG_RTC_INTF_SYSFS
258 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp);
259 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps);
262 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
268 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
273 #endif /* _LINUX_RTC_H_ */