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 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); 28 29 /* 30 * rtc_tm_sub - Return the difference in seconds. 31 */ 32 static 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 static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm) 38 { 39 rtc_time64_to_tm(time, tm); 40 } 41 42 static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time) 43 { 44 *time = rtc_tm_to_time64(tm); 45 46 return 0; 47 } 48 49 #include <linux/device.h> 50 #include <linux/seq_file.h> 51 #include <linux/cdev.h> 52 #include <linux/poll.h> 53 #include <linux/mutex.h> 54 #include <linux/timerqueue.h> 55 #include <linux/workqueue.h> 56 57 extern struct class *rtc_class; 58 59 /* 60 * For these RTC methods the device parameter is the physical device 61 * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which 62 * was passed to rtc_device_register(). Its driver_data normally holds 63 * device state, including the rtc_device pointer for the RTC. 64 * 65 * Most of these methods are called with rtc_device.ops_lock held, 66 * through the rtc_*(struct rtc_device *, ...) calls. 67 * 68 * The (current) exceptions are mostly filesystem hooks: 69 * - the proc() hook for procfs 70 * - non-ioctl() chardev hooks: open(), release() 71 * 72 * REVISIT those periodic irq calls *do* have ops_lock when they're 73 * issued through ioctl() ... 74 */ 75 struct rtc_class_ops { 76 int (*ioctl)(struct device *, unsigned int, unsigned long); 77 int (*read_time)(struct device *, struct rtc_time *); 78 int (*set_time)(struct device *, struct rtc_time *); 79 int (*read_alarm)(struct device *, struct rtc_wkalrm *); 80 int (*set_alarm)(struct device *, struct rtc_wkalrm *); 81 int (*proc)(struct device *, struct seq_file *); 82 int (*alarm_irq_enable)(struct device *, unsigned int enabled); 83 int (*read_offset)(struct device *, long *offset); 84 int (*set_offset)(struct device *, long offset); 85 }; 86 87 struct rtc_device; 88 89 struct rtc_timer { 90 struct timerqueue_node node; 91 ktime_t period; 92 void (*func)(struct rtc_device *rtc); 93 struct rtc_device *rtc; 94 int enabled; 95 }; 96 97 /* flags */ 98 #define RTC_DEV_BUSY 0 99 100 struct rtc_device { 101 struct device dev; 102 struct module *owner; 103 104 int id; 105 106 const struct rtc_class_ops *ops; 107 struct mutex ops_lock; 108 109 struct cdev char_dev; 110 unsigned long flags; 111 112 unsigned long irq_data; 113 spinlock_t irq_lock; 114 wait_queue_head_t irq_queue; 115 struct fasync_struct *async_queue; 116 117 int irq_freq; 118 int max_user_freq; 119 120 struct timerqueue_head timerqueue; 121 struct rtc_timer aie_timer; 122 struct rtc_timer uie_rtctimer; 123 struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */ 124 int pie_enabled; 125 struct work_struct irqwork; 126 /* Some hardware can't support UIE mode */ 127 int uie_unsupported; 128 129 /* Number of nsec it takes to set the RTC clock. This influences when 130 * the set ops are called. An offset: 131 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s 132 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s 133 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s 134 */ 135 long set_offset_nsec; 136 137 bool registered; 138 139 /* Old ABI support */ 140 bool nvram_old_abi; 141 struct bin_attribute *nvram; 142 143 time64_t range_min; 144 timeu64_t range_max; 145 time64_t start_secs; 146 time64_t offset_secs; 147 bool set_start_time; 148 149 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL 150 struct work_struct uie_task; 151 struct timer_list uie_timer; 152 /* Those fields are protected by rtc->irq_lock */ 153 unsigned int oldsecs; 154 unsigned int uie_irq_active:1; 155 unsigned int stop_uie_polling:1; 156 unsigned int uie_task_active:1; 157 unsigned int uie_timer_active:1; 158 #endif 159 }; 160 #define to_rtc_device(d) container_of(d, struct rtc_device, dev) 161 162 #define rtc_lock(d) mutex_lock(&d->ops_lock) 163 #define rtc_unlock(d) mutex_unlock(&d->ops_lock) 164 165 /* useful timestamps */ 166 #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */ 167 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */ 168 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */ 169 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */ 170 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */ 171 #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */ 172 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */ 173 174 extern struct rtc_device *devm_rtc_device_register(struct device *dev, 175 const char *name, 176 const struct rtc_class_ops *ops, 177 struct module *owner); 178 struct rtc_device *devm_rtc_allocate_device(struct device *dev); 179 int __rtc_register_device(struct module *owner, struct rtc_device *rtc); 180 181 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm); 182 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm); 183 extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec); 184 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm); 185 extern int rtc_read_alarm(struct rtc_device *rtc, 186 struct rtc_wkalrm *alrm); 187 extern int rtc_set_alarm(struct rtc_device *rtc, 188 struct rtc_wkalrm *alrm); 189 extern int rtc_initialize_alarm(struct rtc_device *rtc, 190 struct rtc_wkalrm *alrm); 191 extern void rtc_update_irq(struct rtc_device *rtc, 192 unsigned long num, unsigned long events); 193 194 extern struct rtc_device *rtc_class_open(const char *name); 195 extern void rtc_class_close(struct rtc_device *rtc); 196 197 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled); 198 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq); 199 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled); 200 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled); 201 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, 202 unsigned int enabled); 203 204 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode); 205 void rtc_aie_update_irq(struct rtc_device *rtc); 206 void rtc_uie_update_irq(struct rtc_device *rtc); 207 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); 208 209 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r), 210 struct rtc_device *rtc); 211 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, 212 ktime_t expires, ktime_t period); 213 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer); 214 int rtc_read_offset(struct rtc_device *rtc, long *offset); 215 int rtc_set_offset(struct rtc_device *rtc, long offset); 216 void rtc_timer_do_work(struct work_struct *work); 217 218 static inline bool is_leap_year(unsigned int year) 219 { 220 return (!(year % 4) && (year % 100)) || !(year % 400); 221 } 222 223 /* Determine if we can call to driver to set the time. Drivers can only be 224 * called to set a second aligned time value, and the field set_offset_nsec 225 * specifies how far away from the second aligned time to call the driver. 226 * 227 * This also computes 'to_set' which is the time we are trying to set, and has 228 * a zero in tv_nsecs, such that: 229 * to_set - set_delay_nsec == now +/- FUZZ 230 * 231 */ 232 static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec, 233 struct timespec64 *to_set, 234 const struct timespec64 *now) 235 { 236 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */ 237 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5; 238 struct timespec64 delay = {.tv_sec = 0, 239 .tv_nsec = set_offset_nsec}; 240 241 *to_set = timespec64_add(*now, delay); 242 243 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) { 244 to_set->tv_nsec = 0; 245 return true; 246 } 247 248 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) { 249 to_set->tv_sec++; 250 to_set->tv_nsec = 0; 251 return true; 252 } 253 return false; 254 } 255 256 #define rtc_register_device(device) \ 257 __rtc_register_device(THIS_MODULE, device) 258 259 #ifdef CONFIG_RTC_HCTOSYS_DEVICE 260 extern int rtc_hctosys_ret; 261 #else 262 #define rtc_hctosys_ret -ENODEV 263 #endif 264 265 #ifdef CONFIG_RTC_NVMEM 266 int rtc_nvmem_register(struct rtc_device *rtc, 267 struct nvmem_config *nvmem_config); 268 void rtc_nvmem_unregister(struct rtc_device *rtc); 269 #else 270 static inline int rtc_nvmem_register(struct rtc_device *rtc, 271 struct nvmem_config *nvmem_config) 272 { 273 return 0; 274 } 275 static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {} 276 #endif 277 278 #ifdef CONFIG_RTC_INTF_SYSFS 279 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp); 280 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps); 281 #else 282 static inline 283 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) 284 { 285 return 0; 286 } 287 288 static inline 289 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps) 290 { 291 return 0; 292 } 293 #endif 294 #endif /* _LINUX_RTC_H_ */ 295