LXR linux/include/linux/rtc.h

   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
  21extern int rtc_month_days(unsigned int month, unsigned int year);
  22extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
  23extern int rtc_valid_tm(struct rtc_time *tm);
  24extern time64_t rtc_tm_to_time64(struct rtc_time *tm);
  25extern void rtc_time64_to_tm(time64_t time, struct rtc_time *tm);
  26ktime_t rtc_tm_to_ktime(struct rtc_time tm);
  27struct rtc_time rtc_ktime_to_tm(ktime_t kt);
  28
  29/*
  30 * rtc_tm_sub - Return the difference in seconds.
  31 */
  32static 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
  37static inline void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
  38{
  39        rtc_time64_to_tm(time, tm);
  40}
  41
  42static 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
  57extern 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 */
  75struct 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#define RTC_DEVICE_NAME_SIZE 20
  91typedef struct rtc_task {
  92        void (*func)(void *private_data);
  93        void *private_data;
  94} rtc_task_t;
  95
  96
  97struct rtc_timer {
  98        struct rtc_task task;
  99        struct timerqueue_node node;
 100        ktime_t period;
 101        int enabled;
 102};
 103
 104
 105/* flags */
 106#define RTC_DEV_BUSY 0
 107
 108struct rtc_device {
 109        struct device dev;
 110        struct module *owner;
 111
 112        int id;
 113
 114        const struct rtc_class_ops *ops;
 115        struct mutex ops_lock;
 116
 117        struct cdev char_dev;
 118        unsigned long flags;
 119
 120        unsigned long irq_data;
 121        spinlock_t irq_lock;
 122        wait_queue_head_t irq_queue;
 123        struct fasync_struct *async_queue;
 124
 125        struct rtc_task *irq_task;
 126        spinlock_t irq_task_lock;
 127        int irq_freq;
 128        int max_user_freq;
 129
 130        struct timerqueue_head timerqueue;
 131        struct rtc_timer aie_timer;
 132        struct rtc_timer uie_rtctimer;
 133        struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
 134        int pie_enabled;
 135        struct work_struct irqwork;
 136        /* Some hardware can't support UIE mode */
 137        int uie_unsupported;
 138
 139        bool registered;
 140
 141        struct nvmem_config *nvmem_config;
 142        struct nvmem_device *nvmem;
 143        /* Old ABI support */
 144        bool nvram_old_abi;
 145        struct bin_attribute *nvram;
 146
 147#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
 148        struct work_struct uie_task;
 149        struct timer_list uie_timer;
 150        /* Those fields are protected by rtc->irq_lock */
 151        unsigned int oldsecs;
 152        unsigned int uie_irq_active:1;
 153        unsigned int stop_uie_polling:1;
 154        unsigned int uie_task_active:1;
 155        unsigned int uie_timer_active:1;
 156#endif
 157};
 158#define to_rtc_device(d) container_of(d, struct rtc_device, dev)
 159
 160extern struct rtc_device *rtc_device_register(const char *name,
 161                                        struct device *dev,
 162                                        const struct rtc_class_ops *ops,
 163                                        struct module *owner);
 164extern struct rtc_device *devm_rtc_device_register(struct device *dev,
 165                                        const char *name,
 166                                        const struct rtc_class_ops *ops,
 167                                        struct module *owner);
 168struct rtc_device *devm_rtc_allocate_device(struct device *dev);
 169int __rtc_register_device(struct module *owner, struct rtc_device *rtc);
 170extern void rtc_device_unregister(struct rtc_device *rtc);
 171extern void devm_rtc_device_unregister(struct device *dev,
 172                                        struct rtc_device *rtc);
 173
 174extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 175extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
 176extern int rtc_set_ntp_time(struct timespec64 now);
 177int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
 178extern int rtc_read_alarm(struct rtc_device *rtc,
 179                        struct rtc_wkalrm *alrm);
 180extern int rtc_set_alarm(struct rtc_device *rtc,
 181                                struct rtc_wkalrm *alrm);
 182extern int rtc_initialize_alarm(struct rtc_device *rtc,
 183                                struct rtc_wkalrm *alrm);
 184extern void rtc_update_irq(struct rtc_device *rtc,
 185                        unsigned long num, unsigned long events);
 186
 187extern struct rtc_device *rtc_class_open(const char *name);
 188extern void rtc_class_close(struct rtc_device *rtc);
 189
 190extern int rtc_irq_register(struct rtc_device *rtc,
 191                                struct rtc_task *task);
 192extern void rtc_irq_unregister(struct rtc_device *rtc,
 193                                struct rtc_task *task);
 194extern int rtc_irq_set_state(struct rtc_device *rtc,
 195                                struct rtc_task *task, int enabled);
 196extern int rtc_irq_set_freq(struct rtc_device *rtc,
 197                                struct rtc_task *task, int freq);
 198extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 199extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
 200extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
 201                                                unsigned int enabled);
 202
 203void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
 204void rtc_aie_update_irq(void *private);
 205void rtc_uie_update_irq(void *private);
 206enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
 207
 208int rtc_register(rtc_task_t *task);
 209int rtc_unregister(rtc_task_t *task);
 210int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
 211
 212void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data);
 213int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
 214                    ktime_t expires, ktime_t period);
 215void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer);
 216int rtc_read_offset(struct rtc_device *rtc, long *offset);
 217int rtc_set_offset(struct rtc_device *rtc, long offset);
 218void rtc_timer_do_work(struct work_struct *work);
 219
 220static inline bool is_leap_year(unsigned int year)
 221{
 222        return (!(year % 4) && (year % 100)) || !(year % 400);
 223}
 224
 225#define rtc_register_device(device) \
 226        __rtc_register_device(THIS_MODULE, device)
 227
 228#ifdef CONFIG_RTC_HCTOSYS_DEVICE
 229extern int rtc_hctosys_ret;
 230#else
 231#define rtc_hctosys_ret -ENODEV
 232#endif
 233
 234#endif /* _LINUX_RTC_H_ */
 235