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 /* useful timestamps */ 163 #define RTC_TIMESTAMP_BEGIN_1900 -2208988800LL /* 1900-01-01 00:00:00 */ 164 #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */ 165 #define RTC_TIMESTAMP_END_2063 2966371199LL /* 2063-12-31 23:59:59 */ 166 #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */ 167 #define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */ 168 169 extern struct rtc_device *devm_rtc_device_register(struct device *dev, 170 const char *name, 171 const struct rtc_class_ops *ops, 172 struct module *owner); 173 struct rtc_device *devm_rtc_allocate_device(struct device *dev); 174 int __rtc_register_device(struct module *owner, struct rtc_device *rtc); 175 176 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm); 177 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm); 178 extern int rtc_set_ntp_time(struct timespec64 now, unsigned long *target_nsec); 179 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm); 180 extern int rtc_read_alarm(struct rtc_device *rtc, 181 struct rtc_wkalrm *alrm); 182 extern int rtc_set_alarm(struct rtc_device *rtc, 183 struct rtc_wkalrm *alrm); 184 extern int rtc_initialize_alarm(struct rtc_device *rtc, 185 struct rtc_wkalrm *alrm); 186 extern void rtc_update_irq(struct rtc_device *rtc, 187 unsigned long num, unsigned long events); 188 189 extern struct rtc_device *rtc_class_open(const char *name); 190 extern void rtc_class_close(struct rtc_device *rtc); 191 192 extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled); 193 extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq); 194 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled); 195 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled); 196 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, 197 unsigned int enabled); 198 199 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode); 200 void rtc_aie_update_irq(struct rtc_device *rtc); 201 void rtc_uie_update_irq(struct rtc_device *rtc); 202 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); 203 204 void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r), 205 struct rtc_device *rtc); 206 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, 207 ktime_t expires, ktime_t period); 208 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer); 209 int rtc_read_offset(struct rtc_device *rtc, long *offset); 210 int rtc_set_offset(struct rtc_device *rtc, long offset); 211 void rtc_timer_do_work(struct work_struct *work); 212 213 static inline bool is_leap_year(unsigned int year) 214 { 215 return (!(year % 4) && (year % 100)) || !(year % 400); 216 } 217 218 /* Determine if we can call to driver to set the time. Drivers can only be 219 * called to set a second aligned time value, and the field set_offset_nsec 220 * specifies how far away from the second aligned time to call the driver. 221 * 222 * This also computes 'to_set' which is the time we are trying to set, and has 223 * a zero in tv_nsecs, such that: 224 * to_set - set_delay_nsec == now +/- FUZZ 225 * 226 */ 227 static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec, 228 struct timespec64 *to_set, 229 const struct timespec64 *now) 230 { 231 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */ 232 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5; 233 struct timespec64 delay = {.tv_sec = 0, 234 .tv_nsec = set_offset_nsec}; 235 236 *to_set = timespec64_add(*now, delay); 237 238 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) { 239 to_set->tv_nsec = 0; 240 return true; 241 } 242 243 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) { 244 to_set->tv_sec++; 245 to_set->tv_nsec = 0; 246 return true; 247 } 248 return false; 249 } 250 251 #define rtc_register_device(device) \ 252 __rtc_register_device(THIS_MODULE, device) 253 254 #ifdef CONFIG_RTC_HCTOSYS_DEVICE 255 extern int rtc_hctosys_ret; 256 #else 257 #define rtc_hctosys_ret -ENODEV 258 #endif 259 260 #ifdef CONFIG_RTC_NVMEM 261 int rtc_nvmem_register(struct rtc_device *rtc, 262 struct nvmem_config *nvmem_config); 263 void rtc_nvmem_unregister(struct rtc_device *rtc); 264 #else 265 static inline int rtc_nvmem_register(struct rtc_device *rtc, 266 struct nvmem_config *nvmem_config) 267 { 268 return 0; 269 } 270 static inline void rtc_nvmem_unregister(struct rtc_device *rtc) {} 271 #endif 272 273 #ifdef CONFIG_RTC_INTF_SYSFS 274 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp); 275 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps); 276 #else 277 static inline 278 int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) 279 { 280 return 0; 281 } 282 283 static inline 284 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps) 285 { 286 return 0; 287 } 288 #endif 289 #endif /* _LINUX_RTC_H_ */ 290