include/linux/rtc.h

   1 /*
   2  * Generic RTC interface.
   3  * This version contains the part of the user interface to the Real Time Clock
   4  * service. It is used with both the legacy mc146818 and also  EFI
   5  * Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
   6  * from <linux/mc146818rtc.h> to this file for 2.4 kernels.
   7  *
   8  * Copyright (C) 1999 Hewlett-Packard Co.
   9  * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
  10  */
  11 #ifndef _LINUX_RTC_H_
  12 #define _LINUX_RTC_H_
  13
  14
  15 #include <linux/types.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/nvmem-provider.h>
  18 #include <uapi/linux/rtc.h>
  19
  20 extern int rtc_month_days(unsigned int month, unsigned int year);
  21 extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
  22 extern int rtc_valid_tm(struct rtc_time *tm);
  23 extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
  24 extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
  25 ktime_t rtc_tm_to_ktime(struct rtc_time tm);
  26 struct rtc_time rtc_ktime_to_tm(ktime_t kt);
  27
  28 /*
  29  * rtc_tm_sub - Return the difference in seconds.
  30  */
  31 static inline time64_t rtc_tm_sub(struct rtc_time *lhs, struct rtc_time *rhs)
  32 {
  33         return rtc_tm_to_time64(lhs) - rtc_tm_to_time64(rhs);
  34 }
  35
  36 static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
  37 {
  38         rtc_time64_to_tm(time, tm);
  39 }
  40
  41 static inline int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
  42 {
  43         *time = rtc_tm_to_time64(tm);
  44
  45         return 0;
  46 }
  47
  48 #include <linux/device.h>
  49 #include <linux/seq_file.h>
  50 #include <linux/cdev.h>
  51 #include <linux/poll.h>
  52 #include <linux/mutex.h>
  53 #include <linux/timerqueue.h>
  54 #include <linux/workqueue.h>
  55
  56 extern struct class *rtc_class;
  57
  58 /*
  59  * For these RTC methods the device parameter is the physical device
  60  * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
  61  * was passed to rtc_device_register().  Its driver_data normally holds
  62  * device state, including the rtc_device pointer for the RTC.
  63  *
  64  * Most of these methods are called with rtc_device.ops_lock held,
  65  * through the rtc_*(struct rtc_device *, ...) calls.
  66  *
  67  * The (current) exceptions are mostly filesystem hooks:
  68  *   - the proc() hook for procfs
  69  *   - non-ioctl() chardev hooks:  open(), release(), read_callback()
  70  *
  71  * REVISIT those periodic irq calls *do* have ops_lock when they're
  72  * issued through ioctl() ...
  73  */
  74 struct rtc_class_ops {
  75         int (*ioctl)(struct device *, unsigned int, unsigned long);
  76         int (*read_time)(struct device *, struct rtc_time *);
  77         int (*set_time)(struct device *, struct rtc_time *);
  78         int (*read_alarm)(struct device *, struct rtc_wkalrm *);
  79         int (*set_alarm)(struct device *, struct rtc_wkalrm *);
  80         int (*proc)(struct device *, struct seq_file *);
  81         int (*set_mmss64)(struct device *, time64_t secs);
  82         int (*set_mmss)(struct device *, unsigned long secs);
  83         int (*read_callback)(struct device *, int data);
  84         int (*alarm_irq_enable)(struct device *, unsigned int enabled);
  85         int (*read_offset)(struct device *, long *offset);
  86         int (*set_offset)(struct device *, long offset);
  87 };
  88
  89 #define RTC_DEVICE_NAME_SIZE 20
  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         bool registered;
 139
 140         struct nvmem_config *nvmem_config;
 141         struct nvmem_device *nvmem;
 142         /* Old ABI support */
 143         bool nvram_old_abi;
 144         struct bin_attribute *nvram;
 145
 146 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
 147         struct work_struct uie_task;
 148         struct timer_list uie_timer;
 149         /* Those fields are protected by rtc->irq_lock */
 150         unsigned int oldsecs;
 151         unsigned int uie_irq_active:1;
 152         unsigned int stop_uie_polling:1;
 153         unsigned int uie_task_active:1;
 154         unsigned int uie_timer_active:1;
 155 #endif
 156 };
 157 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
 158
 159 extern struct rtc_device *rtc_device_register(const char *name,
 160                                         struct device *dev,
 161                                         const struct rtc_class_ops *ops,
 162                                         struct module *owner);
 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 extern void rtc_device_unregister(struct rtc_device *rtc);
 170 extern void devm_rtc_device_unregister(struct device *dev,
 171                                         struct rtc_device *rtc);
 172
 173 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 174 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
 175 extern int rtc_set_ntp_time(struct timespec64 now);
 176 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
 177 extern int rtc_read_alarm(struct rtc_device *rtc,
 178                         struct rtc_wkalrm *alrm);
 179 extern int rtc_set_alarm(struct rtc_device *rtc,
 180                                 struct rtc_wkalrm *alrm);
 181 extern int rtc_initialize_alarm(struct rtc_device *rtc,
 182                                 struct rtc_wkalrm *alrm);
 183 extern void rtc_update_irq(struct rtc_device *rtc,
 184                         unsigned long num, unsigned long events);
 185
 186 extern struct rtc_device *rtc_class_open(const char *name);
 187 extern void rtc_class_close(struct rtc_device *rtc);
 188
 189 extern int rtc_irq_register(struct rtc_device *rtc,
 190                                 struct rtc_task *task);
 191 extern void rtc_irq_unregister(struct rtc_device *rtc,
 192                                 struct rtc_task *task);
 193 extern int rtc_irq_set_state(struct rtc_device *rtc,
 194                                 struct rtc_task *task, int enabled);
 195 extern int rtc_irq_set_freq(struct rtc_device *rtc,
 196                                 struct rtc_task *task, int freq);
 197 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 198 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 199 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
 200                                                 unsigned int enabled);
 201
 202 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
 203 void rtc_aie_update_irq(void *private);
 204 void rtc_uie_update_irq(void *private);
 205 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
 206
 207 int rtc_register(rtc_task_t *task);
 208 int rtc_unregister(rtc_task_t *task);
 209 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
 210
 211 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
 212 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
 213                     ktime_t expires, ktime_t period);
 214 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
 215 int rtc_read_offset(struct rtc_device *rtc, long *offset);
 216 int rtc_set_offset(struct rtc_device *rtc, long offset);
 217 void rtc_timer_do_work(struct work_struct *work);
 218
 219 static inline bool is_leap_year(unsigned int year)
 220 {
 221         return (!(year % 4) && (year % 100)) || !(year % 400);
 222 }
 223
 224 #define rtc_register_device(device) \
 225         __rtc_register_device(THIS_MODULE, device)
 226
 227 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
 228 extern int rtc_hctosys_ret;
 229 #else
 230 #define rtc_hctosys_ret -ENODEV
 231 #endif
 232
 233 #endif /* _LINUX_RTC_H_ */