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 21extern int rtc_month_days(unsigned int month, unsigned int year); 22extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year); 23extern int rtc_valid_tm(struct rtc_time *tm); 24extern time64_t rtc_tm_to_time64(struct rtc_time *tm); 25extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm); 26ktime_t rtc_tm_to_ktime(struct rtc_time tm); 27struct rtc_time rtc_ktime_to_tm(ktime_t kt); 28 29/* 30 * rtc_tm_sub - Return the difference in seconds. 31 */ 32static 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 45extern const 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 */ 59struct 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 int (*param_get)(struct device *, struct rtc_param *param); 70 int (*param_set)(struct device *, struct rtc_param *param); 71}; 72 73struct rtc_device; 74 75struct rtc_timer { 76 struct timerqueue_node node; 77 ktime_t period; 78 void (*func)(struct rtc_device *rtc); 79 struct rtc_device *rtc; 80 int enabled; 81}; 82 83/* flags */ 84#define RTC_DEV_BUSY 0 85#define RTC_NO_CDEV 1 86 87struct 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; 113 114 /* 115 * This offset specifies the update timing of the RTC. 116 * 117 * tsched t1 write(t2.tv_sec - 1sec)) t2 RTC increments seconds 118 * 119 * The offset defines how tsched is computed so that the write to 120 * the RTC (t2.tv_sec - 1sec) is correct versus the time required 121 * for the transport of the write and the time which the RTC needs 122 * to increment seconds the first time after the write (t2). 123 * 124 * For direct accessible RTCs tsched ~= t1 because the write time 125 * is negligible. For RTCs behind slow busses the transport time is 126 * significant and has to be taken into account. 127 * 128 * The time between the write (t1) and the first increment after 129 * the write (t2) is RTC specific. For a MC146818 RTC it's 500ms, 130 * for many others it's exactly 1 second. Consult the datasheet. 131 * 132 * The value of this offset is also used to calculate the to be 133 * written value (t2.tv_sec - 1sec) at tsched. 134 * 135 * The default value for this is NSEC_PER_SEC + 10 msec default 136 * transport time. The offset can be adjusted by drivers so the 137 * calculation for the to be written value at tsched becomes 138 * correct: 139 * 140 * newval = tsched + set_offset_nsec - NSEC_PER_SEC 141 * and (tsched + set_offset_nsec) % NSEC_PER_SEC == 0 142 */ 143 unsigned long set_offset_nsec; 144 145 unsigned long features[BITS_TO_LONGS(RTC_FEATURE_CNT)]; 146 147 time64_t range_min; 148 timeu64_t range_max; 149 timeu64_t alarm_offset_max; 150 time64_t start_secs; 151 time64_t offset_secs; 152 bool set_start_time; 153 154#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL 155 struct work_struct uie_task; 156 struct timer_list uie_timer; 157 /* Those fields are protected by rtc->irq_lock */ 158 unsigned int oldsecs; 159 unsigned int uie_irq_active:1; 160 unsigned int stop_uie_polling:1; 161 unsigned int uie_task_active:1; 162 unsigned int uie_timer_active:1; 163#endif 164}; 165#define to_rtc_device(d) container_of(d, struct rtc_device, dev) 166 167#define rtc_lock(d) mutex_lock(&d->ops_lock) 168#define rtc_unlock(d) mutex_unlock(&d->ops_lock) 169 170/* useful timestamps */ 171#define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */ 172#define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */ 173#define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */ 174#define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */ 175#define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */ 176#define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */ 177#define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */ 178#define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */ 179 180extern struct rtc_device *devm_rtc_device_register(struct device *dev, 181 const char *name, 182 const struct rtc_class_ops *ops, 183 struct module *owner); 184struct rtc_device *devm_rtc_allocate_device(struct device *dev); 185int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc); 186 187extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm); 188extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm); 189int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm); 190extern int rtc_read_alarm(struct rtc_device *rtc, 191 struct rtc_wkalrm *alrm); 192extern int rtc_set_alarm(struct rtc_device *rtc, 193 struct rtc_wkalrm *alrm); 194extern int rtc_initialize_alarm(struct rtc_device *rtc, 195 struct rtc_wkalrm *alrm); 196extern void rtc_update_irq(struct rtc_device *rtc, 197 unsigned long num, unsigned long events); 198 199extern struct rtc_device *rtc_class_open(const char *name); 200extern void rtc_class_close(struct rtc_device *rtc); 201 202extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled); 203extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq); 204extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled); 205extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled); 206extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, 207 unsigned int enabled); 208 209void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode); 210void rtc_aie_update_irq(struct rtc_device *rtc); 211void rtc_uie_update_irq(struct rtc_device *rtc); 212enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); 213 214void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r), 215 struct rtc_device *rtc); 216int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, 217 ktime_t expires, ktime_t period); 218void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer); 219int rtc_read_offset(struct rtc_device *rtc, long *offset); 220int rtc_set_offset(struct rtc_device *rtc, long offset); 221void rtc_timer_do_work(struct work_struct *work); 222 223static inline bool is_leap_year(unsigned int year) 224{ 225 return (!(year % 4) && (year % 100)) || !(year % 400); 226} 227 228/** 229 * rtc_bound_alarmtime() - Return alarm time bound by rtc limit 230 * @rtc: Pointer to rtc device structure 231 * @requested: Requested alarm timeout 232 * 233 * Return: Alarm timeout bound by maximum alarm time supported by rtc. 234 */ 235static inline ktime_t rtc_bound_alarmtime(struct rtc_device *rtc, 236 ktime_t requested) 237{ 238 if (rtc->alarm_offset_max && 239 rtc->alarm_offset_max * MSEC_PER_SEC < ktime_to_ms(requested)) 240 return ms_to_ktime(rtc->alarm_offset_max * MSEC_PER_SEC); 241 242 return requested; 243} 244 245#define devm_rtc_register_device(device) \ 246 __devm_rtc_register_device(THIS_MODULE, device) 247 248#ifdef CONFIG_RTC_HCTOSYS_DEVICE 249extern int rtc_hctosys_ret; 250#else 251#define rtc_hctosys_ret -ENODEV 252#endif 253 254#ifdef CONFIG_RTC_NVMEM 255int devm_rtc_nvmem_register(struct rtc_device *rtc, 256 struct nvmem_config *nvmem_config); 257#else 258static inline int devm_rtc_nvmem_register(struct rtc_device *rtc, 259 struct nvmem_config *nvmem_config) 260{ 261 return 0; 262} 263#endif 264 265#ifdef CONFIG_RTC_INTF_SYSFS 266int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp); 267int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps); 268#else 269static inline 270int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) 271{ 272 return 0; 273} 274 275static inline 276int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps) 277{ 278 return 0; 279} 280#endif 281#endif /* _LINUX_RTC_H_ */ 282