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(), read_callback() 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 (*set_mmss64)(struct device *, time64_t secs); 83 int (*set_mmss)(struct device *, unsigned long secs); 84 int (*read_callback)(struct device *, int data); 85 int (*alarm_irq_enable)(struct device *, unsigned int enabled); 86 int (*read_offset)(struct device *, long *offset); 87 int (*set_offset)(struct device *, long offset); 88 }; 89 90 typedef struct rtc_task { 91 void (*func)(void *private_data); 92 void *private_data; 93 } rtc_task_t; 94 95 96 struct rtc_timer { 97 struct rtc_task task; 98 struct timerqueue_node node; 99 ktime_t period; 100 int enabled; 101 }; 102 103 104 /* flags */ 105 #define RTC_DEV_BUSY 0 106 107 struct rtc_device { 108 struct device dev; 109 struct module *owner; 110 111 int id; 112 113 const struct rtc_class_ops *ops; 114 struct mutex ops_lock; 115 116 struct cdev char_dev; 117 unsigned long flags; 118 119 unsigned long irq_data; 120 spinlock_t irq_lock; 121 wait_queue_head_t irq_queue; 122 struct fasync_struct *async_queue; 123 124 struct rtc_task *irq_task; 125 spinlock_t irq_task_lock; 126 int irq_freq; 127 int max_user_freq; 128 129 struct timerqueue_head timerqueue; 130 struct rtc_timer aie_timer; 131 struct rtc_timer uie_rtctimer; 132 struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */ 133 int pie_enabled; 134 struct work_struct irqwork; 135 /* Some hardware can't support UIE mode */ 136 int uie_unsupported; 137 138 /* Number of nsec it takes to set the RTC clock. This influences when 139 * the set ops are called. An offset: 140 * - of 0.5 s will call RTC set for wall clock time 10.0 s at 9.5 s 141 * - of 1.5 s will call RTC set for wall clock time 10.0 s at 8.5 s 142 * - of -0.5 s will call RTC set for wall clock time 10.0 s at 10.5 s 143 */ 144 long set_offset_nsec; 145 146 bool registered; 147 148 struct nvmem_config *nvmem_config; 149 struct nvmem_device *nvmem; 150 /* Old ABI support */ 151 bool nvram_old_abi; 152 struct bin_attribute *nvram; 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 extern struct rtc_device *rtc_device_register(const char *name, 168 struct device *dev, 169 const struct rtc_class_ops *ops, 170 struct module *owner); 171 extern struct rtc_device *devm_rtc_device_register(struct device *dev, 172 const char *name, 173 const struct rtc_class_ops *ops, 174 struct module *owner); 175 struct rtc_device *devm_rtc_allocate_device(struct device *dev); 176 int __rtc_register_device(struct module *owner, struct rtc_device *rtc); 177 extern void rtc_device_unregister(struct rtc_device *rtc); 178 extern void devm_rtc_device_unregister(struct device *dev, 179 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_register(struct rtc_device *rtc, 198 struct rtc_task *task); 199 extern void rtc_irq_unregister(struct rtc_device *rtc, 200 struct rtc_task *task); 201 extern int rtc_irq_set_state(struct rtc_device *rtc, 202 struct rtc_task *task, int enabled); 203 extern int rtc_irq_set_freq(struct rtc_device *rtc, 204 struct rtc_task *task, int freq); 205 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled); 206 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled); 207 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, 208 unsigned int enabled); 209 210 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode); 211 void rtc_aie_update_irq(void *private); 212 void rtc_uie_update_irq(void *private); 213 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer); 214 215 int rtc_register(rtc_task_t *task); 216 int rtc_unregister(rtc_task_t *task); 217 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg); 218 219 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data); 220 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, 221 ktime_t expires, ktime_t period); 222 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer); 223 int rtc_read_offset(struct rtc_device *rtc, long *offset); 224 int rtc_set_offset(struct rtc_device *rtc, long offset); 225 void rtc_timer_do_work(struct work_struct *work); 226 227 static inline bool is_leap_year(unsigned int year) 228 { 229 return (!(year % 4) && (year % 100)) || !(year % 400); 230 } 231 232 /* Determine if we can call to driver to set the time. Drivers can only be 233 * called to set a second aligned time value, and the field set_offset_nsec 234 * specifies how far away from the second aligned time to call the driver. 235 * 236 * This also computes 'to_set' which is the time we are trying to set, and has 237 * a zero in tv_nsecs, such that: 238 * to_set - set_delay_nsec == now +/- FUZZ 239 * 240 */ 241 static inline bool rtc_tv_nsec_ok(s64 set_offset_nsec, 242 struct timespec64 *to_set, 243 const struct timespec64 *now) 244 { 245 /* Allowed error in tv_nsec, arbitarily set to 5 jiffies in ns. */ 246 const unsigned long TIME_SET_NSEC_FUZZ = TICK_NSEC * 5; 247 struct timespec64 delay = {.tv_sec = 0, 248 .tv_nsec = set_offset_nsec}; 249 250 *to_set = timespec64_add(*now, delay); 251 252 if (to_set->tv_nsec < TIME_SET_NSEC_FUZZ) { 253 to_set->tv_nsec = 0; 254 return true; 255 } 256 257 if (to_set->tv_nsec > NSEC_PER_SEC - TIME_SET_NSEC_FUZZ) { 258 to_set->tv_sec++; 259 to_set->tv_nsec = 0; 260 return true; 261 } 262 return false; 263 } 264 265 #define rtc_register_device(device) \ 266 __rtc_register_device(THIS_MODULE, device) 267 268 #ifdef CONFIG_RTC_HCTOSYS_DEVICE 269 extern int rtc_hctosys_ret; 270 #else 271 #define rtc_hctosys_ret -ENODEV 272 #endif 273 274 #endif /* _LINUX_RTC_H_ */ 275