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 #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 45 extern 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 * - non-ioctl() chardev hooks: open(), release() 59 * 60 * REVISIT those periodic irq calls *do* have ops_lock when they're 61 * issued through ioctl() ... 62 */ 63 struct rtc_class_ops { 64 int (*ioctl)(struct device *, unsigned int, unsigned long); 65 int (*read_time)(struct device *, struct rtc_time *); 66 int (*set_time)(struct device *, struct rtc_time *); 67 int (*read_alarm)(struct device *, struct rtc_wkalrm *); 68 int (*set_alarm)(struct device *, struct rtc_wkalrm *); 69 int (*proc)(struct device *, struct seq_file *); 70 int (*alarm_irq_enable)(struct device *, unsigned int enabled); 71 int (*read_offset)(struct device *, long *offset); 72 int (*set_offset)(struct device *, long offset); 73 }; 74 75 struct rtc_device; 76 77 struct rtc_timer { 78 struct timerqueue_node node; 79 ktime_t period; 80 void (*func)(struct rtc_device *rtc); 81 struct rtc_device *rtc; 82 int enabled; 83 }; 84 85 /* flags */ 86 #define RTC_DEV_BUSY 0 87 88 struct rtc_device { 89 struct device dev; 90 struct module *owner; 91 92 int id; 93 94 const struct rtc_class_ops *ops; 95 struct mutex ops_lock; 96 97 struct cdev char_dev; 98 unsigned long flags; 99 100 unsigned long irq_data; 101 spinlock_t irq_lock; 102 wait_queue_head_t irq_queue; 103 struct fasync_struct *async_queue; 104 105 int irq_freq; 106 int max_user_freq; 107 108 struct timerqueue_head timerqueue; 109 struct rtc_timer aie_timer; 110 struct rtc_timer uie_rtctimer; 111 struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */ 112 int pie_enabled; 113 struct work_struct irqwork; 114 /* Some hardware can't support UIE mode */ 115 int uie_unsupported; 116 117 /* Number of nsec it takes to set the RTC clock. This influences when 118 * the set ops are called. An offset: 119 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s 120 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s 121 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s 122 */ 123 long set_offset_nsec; 124 125 bool registered; 126 127 /* Old ABI support */ 128 bool nvram_old_abi; 129 struct bin_attribute *nvram; 130 131 time64_t range_min; 132 timeu64_t range_max; 133 time64_t start_secs; 134 time64_t offset_secs; 135 bool set_start_time; 136 137 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL 138 struct work_struct uie_task; 139 struct timer_list uie_timer; 140 /* Those fields are protected by rtc->irq_lock */ 141 unsigned int oldsecs; 142 unsigned int uie_irq_active:1; 143 unsigned int stop_uie_polling:1; 144 unsigned int uie_task_active:1; 145 unsigned int uie_timer_active:1; 146 #endif 147 }; 148 #define to_rtc_device(d) container_of(d, struct rtc_device, dev) 149 150 #define rtc_lock(d) mutex_lock(&d->ops_lock) 151 #define rtc_unlock(d) mutex_unlock(&d->ops_lock) 152 153 /* useful timestamps */ 154 #define RTC_TIMESTAMP_BEGIN_0000 -62167219200ULL /* 0000-01-01 00:00:00 */ 155 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */ 156 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */ 157 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */ 158 #define RTC_TIMESTAMP_END_2079 3471292799LL /* 2079-12-31 23:59:59 */ 159 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */ 160 #define RTC_TIMESTAMP_END_2199 7258118399LL /* 2199-12-31 23:59:59 */ 161 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */ 162 163 extern struct rtc_device *devm_rtc_device_register(struct device *dev, 164 const char *name, 165 const struct rtc_class_ops *ops, 166 struct module *owner); 167 struct rtc_device *devm_rtc_allocate_device(struct device *dev); 168 int __rtc_register_device(struct module *owner, struct rtc_device *rtc); 169 170 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm); 171 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm); 172 extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec); 173 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm); 174 extern int rtc_read_alarm(struct rtc_device *rtc, 175 struct rtc_wkalrm *alrm); 176 extern int rtc_set_alarm(struct rtc_device *rtc, 177 struct rtc_wkalrm *alrm); 178 extern int rtc_initialize_alarm(struct rtc_device *rtc, 179 struct rtc_wkalrm *alrm); 180 extern void rtc_update_irq(struct rtc_device *rtc, 181 unsigned long num, unsigned long events); 182 183 extern struct rtc_device *rtc_class_open(const char *name); 184 extern void rtc_class_close(struct rtc_device *rtc); 185 186 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled); 187 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq); 188 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled); 189 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled); 190 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, 191 unsigned int enabled); 192 193 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode); 194 void rtc_aie_update_irq(struct rtc_device *rtc); 195 void rtc_uie_update_irq(struct rtc_device *rtc); 196 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); 197 198 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r), 199 struct rtc_device *rtc); 200 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, 201 ktime_t expires, ktime_t period); 202 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer); 203 int rtc_read_offset(struct rtc_device *rtc, long *offset); 204 int rtc_set_offset(struct rtc_device *rtc, long offset); 205 void rtc_timer_do_work(struct work_struct *work); 206 207 static inline bool is_leap_year(unsigned int year) 208 { 209 return (!(year % 4) && (year % 100)) || !(year % 400); 210 } 211 212 /* Determine if we can call to driver to set the time. Drivers can only be 213 * called to set a second aligned time value, and the field set_offset_nsec 214 * specifies how far away from the second aligned time to call the driver. 215 * 216 * This also computes 'to_set' which is the time we are trying to set, and has 217 * a zero in tv_nsecs, such that: 218 * to_set - set_delay_nsec == now +/- FUZZ 219 * 220 */ 221 static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec, 222 struct timespec64 *to_set, 223 const struct timespec64 *now) 224 { 225 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */ 226 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5; 227 struct timespec64 delay = {.tv_sec = 0, 228 .tv_nsec = set_offset_nsec}; 229 230 *to_set = timespec64_add(*now, delay); 231 232 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) { 233 to_set->tv_nsec = 0; 234 return true; 235 } 236 237 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) { 238 to_set->tv_sec++; 239 to_set->tv_nsec = 0; 240 return true; 241 } 242 return false; 243 } 244 245 #define rtc_register_device(device) \ 246 __rtc_register_device(THIS_MODULE, device) 247 248 #ifdef CONFIG_RTC_HCTOSYS_DEVICE 249 extern int rtc_hctosys_ret; 250 #else 251 #define rtc_hctosys_ret -ENODEV 252 #endif 253 254 #ifdef CONFIG_RTC_NVMEM 255 int rtc_nvmem_register(struct rtc_device *rtc, 256 struct nvmem_config *nvmem_config); 257 void rtc_nvmem_unregister(struct rtc_device *rtc); 258 #else 259 static inline int rtc_nvmem_register(struct rtc_device *rtc, 260 struct nvmem_config *nvmem_config) 261 { 262 return 0; 263 } 264 static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {} 265 #endif 266 267 #ifdef CONFIG_RTC_INTF_SYSFS 268 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp); 269 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps); 270 #else 271 static inline 272 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) 273 { 274 return 0; 275 } 276 277 static inline 278 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps) 279 { 280 return 0; 281 } 282 #endif 283 #endif /* _LINUX_RTC_H_ */ 284