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