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 (*open)(struct device *);
  76         void (*release)(struct device *);
  77         int (*ioctl)(struct device *, unsigned int, unsigned long);
  78         int (*read_time)(struct device *, struct rtc_time *);
  79         int (*set_time)(struct device *, struct rtc_time *);
  80         int (*read_alarm)(struct device *, struct rtc_wkalrm *);
  81         int (*set_alarm)(struct device *, struct rtc_wkalrm *);
  82         int (*proc)(struct device *, struct seq_file *);
  83         int (*set_mmss64)(struct device *, time64_t secs);
  84         int (*set_mmss)(struct device *, unsigned long secs);
  85         int (*read_callback)(struct device *, int data);
  86         int (*alarm_irq_enable)(struct device *, unsigned int enabled);
  87         int (*read_offset)(struct device *, long *offset);
  88         int (*set_offset)(struct device *, long offset);
  89 };
  90
  91 #define RTC_DEVICE_NAME_SIZE 20
  92 typedef struct rtc_task {
  93         void (*func)(void *private_data);
  94         void *private_data;
  95 } rtc_task_t;
  96
  97
  98 struct rtc_timer {
  99         struct rtc_task task;
 100         struct timerqueue_node node;
 101         ktime_t period;
 102         int enabled;
 103 };
 104
 105
 106 /* flags */
 107 #define RTC_DEV_BUSY 0
 108
 109 struct rtc_device {
 110         struct device dev;
 111         struct module *owner;
 112
 113         int id;
 114
 115         const struct rtc_class_ops *ops;
 116         struct mutex ops_lock;
 117
 118         struct cdev char_dev;
 119         unsigned long flags;
 120
 121         unsigned long irq_data;
 122         spinlock_t irq_lock;
 123         wait_queue_head_t irq_queue;
 124         struct fasync_struct *async_queue;
 125
 126         struct rtc_task *irq_task;
 127         spinlock_t irq_task_lock;
 128         int irq_freq;
 129         int max_user_freq;
 130
 131         struct timerqueue_head timerqueue;
 132         struct rtc_timer aie_timer;
 133         struct rtc_timer uie_rtctimer;
 134         struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
 135         int pie_enabled;
 136         struct work_struct irqwork;
 137         /* Some hardware can't support UIE mode */
 138         int uie_unsupported;
 139
 140         bool registered;
 141
 142         struct nvmem_config *nvmem_config;
 143         struct nvmem_device *nvmem;
 144         /* Old ABI support */
 145         bool nvram_old_abi;
 146         struct bin_attribute *nvram;
 147
 148 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
 149         struct work_struct uie_task;
 150         struct timer_list uie_timer;
 151         /* Those fields are protected by rtc->irq_lock */
 152         unsigned int oldsecs;
 153         unsigned int uie_irq_active:1;
 154         unsigned int stop_uie_polling:1;
 155         unsigned int uie_task_active:1;
 156         unsigned int uie_timer_active:1;
 157 #endif
 158 };
 159 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
 160
 161 extern struct rtc_device *rtc_device_register(const char *name,
 162                                         struct device *dev,
 163                                         const struct rtc_class_ops *ops,
 164                                         struct module *owner);
 165 extern struct rtc_device *devm_rtc_device_register(struct device *dev,
 166                                         const char *name,
 167                                         const struct rtc_class_ops *ops,
 168                                         struct module *owner);
 169 struct rtc_device *devm_rtc_allocate_device(struct device *dev);
 170 int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
 171 extern void rtc_device_unregister(struct rtc_device *rtc);
 172 extern void devm_rtc_device_unregister(struct device *dev,
 173                                         struct rtc_device *rtc);
 174
 175 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 176 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
 177 extern int rtc_set_ntp_time(struct timespec64 now);
 178 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
 179 extern int rtc_read_alarm(struct rtc_device *rtc,
 180                         struct rtc_wkalrm *alrm);
 181 extern int rtc_set_alarm(struct rtc_device *rtc,
 182                                 struct rtc_wkalrm *alrm);
 183 extern int rtc_initialize_alarm(struct rtc_device *rtc,
 184                                 struct rtc_wkalrm *alrm);
 185 extern void rtc_update_irq(struct rtc_device *rtc,
 186                         unsigned long num, unsigned long events);
 187
 188 extern struct rtc_device *rtc_class_open(const char *name);
 189 extern void rtc_class_close(struct rtc_device *rtc);
 190
 191 extern int rtc_irq_register(struct rtc_device *rtc,
 192                                 struct rtc_task *task);
 193 extern void rtc_irq_unregister(struct rtc_device *rtc,
 194                                 struct rtc_task *task);
 195 extern int rtc_irq_set_state(struct rtc_device *rtc,
 196                                 struct rtc_task *task, int enabled);
 197 extern int rtc_irq_set_freq(struct rtc_device *rtc,
 198                                 struct rtc_task *task, int freq);
 199 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 200 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 201 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
 202                                                 unsigned int enabled);
 203
 204 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
 205 void rtc_aie_update_irq(void *private);
 206 void rtc_uie_update_irq(void *private);
 207 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
 208
 209 int rtc_register(rtc_task_t *task);
 210 int rtc_unregister(rtc_task_t *task);
 211 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
 212
 213 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
 214 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
 215                     ktime_t expires, ktime_t period);
 216 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
 217 int rtc_read_offset(struct rtc_device *rtc, long *offset);
 218 int rtc_set_offset(struct rtc_device *rtc, long offset);
 219 void rtc_timer_do_work(struct work_struct *work);
 220
 221 static inline bool is_leap_year(unsigned int year)
 222 {
 223         return (!(year % 4) && (year % 100)) || !(year % 400);
 224 }
 225
 226 #define rtc_register_device(device) \
 227         __rtc_register_device(THIS_MODULE, device)
 228
 229 #ifdef CONFIG_RTC_HCTOSYS_DEVICE
 230 extern int rtc_hctosys_ret;
 231 #else
 232 #define rtc_hctosys_ret -ENODEV
 233 #endif
 234
 235 #endif /* _LINUX_RTC_H_ */