include/linux/rtc.h

/*
 * Generic RTC interface.
 * This version contains the part of the user interface to the Real Time Clock
 * service. It is used with both the legacy mc146818 and also  EFI
 * Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
 * from <linux/mc146818rtc.h> to this file for 2.4 kernels.
 *
 * Copyright (C) 1999 Hewlett-Packard Co.
 * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
 */
#ifndef _LINUX_RTC_H_
#define _LINUX_RTC_H_

/*
 * The struct used to pass data via the following ioctl. Similar to the
 * struct tm in <time.h>, but it needs to be here so that the kernel
 * source is self contained, allowing cross-compiles, etc. etc.
 */

struct rtc_time {
	int tm_sec;
	int tm_min;
	int tm_hour;
	int tm_mday;
	int tm_mon;
	int tm_year;
	int tm_wday;
	int tm_yday;
	int tm_isdst;
};

/*
 * This data structure is inspired by the EFI (v0.92) wakeup
 * alarm API.
 */
struct rtc_wkalrm {
	unsigned char enabled;	/* 0 = alarm disabled, 1 = alarm enabled */
	unsigned char pending;  /* 0 = alarm not pending, 1 = alarm pending */
	struct rtc_time time;	/* time the alarm is set to */
};

/*
 * Data structure to control PLL correction some better RTC feature
 * pll_value is used to get or set current value of correction,
 * the rest of the struct is used to query HW capabilities.
 * This is modeled after the RTC used in Q40/Q60 computers but
 * should be sufficiently flexible for other devices
 *
 * +ve pll_value means clock will run faster by
 *   pll_value*pll_posmult/pll_clock
 * -ve pll_value means clock will run slower by
 *   pll_value*pll_negmult/pll_clock
 */

struct rtc_pll_info {
	int pll_ctrl;       /* placeholder for fancier control */
	int pll_value;      /* get/set correction value */
	int pll_max;        /* max +ve (faster) adjustment value */
	int pll_min;        /* max -ve (slower) adjustment value */
	int pll_posmult;    /* factor for +ve correction */
	int pll_negmult;    /* factor for -ve correction */
	long pll_clock;     /* base PLL frequency */
};

/*
 * ioctl calls that are permitted to the /dev/rtc interface, if
 * any of the RTC drivers are enabled.
 */

#define RTC_AIE_ON	_IO('p', 0x01)	/* Alarm int. enable on		*/
#define RTC_AIE_OFF	_IO('p', 0x02)	/* ... off			*/
#define RTC_UIE_ON	_IO('p', 0x03)	/* Update int. enable on	*/
#define RTC_UIE_OFF	_IO('p', 0x04)	/* ... off			*/
#define RTC_PIE_ON	_IO('p', 0x05)	/* Periodic int. enable on	*/
#define RTC_PIE_OFF	_IO('p', 0x06)	/* ... off			*/
#define RTC_WIE_ON	_IO('p', 0x0f)  /* Watchdog int. enable on	*/
#define RTC_WIE_OFF	_IO('p', 0x10)  /* ... off			*/

#define RTC_ALM_SET	_IOW('p', 0x07, struct rtc_time) /* Set alarm time  */
#define RTC_ALM_READ	_IOR('p', 0x08, struct rtc_time) /* Read alarm time */
#define RTC_RD_TIME	_IOR('p', 0x09, struct rtc_time) /* Read RTC time   */
#define RTC_SET_TIME	_IOW('p', 0x0a, struct rtc_time) /* Set RTC time    */
#define RTC_IRQP_READ	_IOR('p', 0x0b, unsigned long)	 /* Read IRQ rate   */
#define RTC_IRQP_SET	_IOW('p', 0x0c, unsigned long)	 /* Set IRQ rate    */
#define RTC_EPOCH_READ	_IOR('p', 0x0d, unsigned long)	 /* Read epoch      */
#define RTC_EPOCH_SET	_IOW('p', 0x0e, unsigned long)	 /* Set epoch       */

#define RTC_WKALM_SET	_IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
#define RTC_WKALM_RD	_IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/

#define RTC_PLL_GET	_IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
#define RTC_PLL_SET	_IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */

/* interrupt flags */
#define RTC_IRQF 0x80 /* any of the following is active */
#define RTC_PF 0x40
#define RTC_AF 0x20
#define RTC_UF 0x10

#ifdef __KERNEL__

#include <linux/types.h>
#include <linux/interrupt.h>

extern int rtc_month_days(unsigned int month, unsigned int year);
extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
extern int rtc_valid_tm(struct rtc_time *tm);
extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);

#include <linux/device.h>
#include <linux/seq_file.h>
#include <linux/cdev.h>
#include <linux/poll.h>
#include <linux/mutex.h>

extern struct class *rtc_class;

/*
 * For these RTC methods the device parameter is the physical device
 * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
 * was passed to rtc_device_register().  Its driver_data normally holds
 * device state, including the rtc_device pointer for the RTC.
 *
 * Most of these methods are called with rtc_device.ops_lock held,
 * through the rtc_*(struct rtc_device *, ...) calls.
 *
 * The (current) exceptions are mostly filesystem hooks:
 *   - the proc() hook for procfs
 *   - non-ioctl() chardev hooks:  open(), release(), read_callback()
 *   - periodic irq calls:  irq_set_state(), irq_set_freq()
 *
 * REVISIT those periodic irq calls *do* have ops_lock when they're
 * issued through ioctl() ...
 */
struct rtc_class_ops {
	int (*open)(struct device *);
	void (*release)(struct device *);
	int (*ioctl)(struct device *, unsigned int, unsigned long);
	int (*read_time)(struct device *, struct rtc_time *);
	int (*set_time)(struct device *, struct rtc_time *);
	int (*read_alarm)(struct device *, struct rtc_wkalrm *);
	int (*set_alarm)(struct device *, struct rtc_wkalrm *);
	int (*proc)(struct device *, struct seq_file *);
	int (*set_mmss)(struct device *, unsigned long secs);
	int (*irq_set_state)(struct device *, int enabled);
	int (*irq_set_freq)(struct device *, int freq);
	int (*read_callback)(struct device *, int data);
	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
	int (*update_irq_enable)(struct device *, unsigned int enabled);
};

#define RTC_DEVICE_NAME_SIZE 20
struct rtc_task;

/* flags */
#define RTC_DEV_BUSY 0

struct rtc_device
{
	struct device dev;
	struct module *owner;

	int id;
	char name[RTC_DEVICE_NAME_SIZE];

	const struct rtc_class_ops *ops;
	struct mutex ops_lock;

	struct cdev char_dev;
	unsigned long flags;

	unsigned long irq_data;
	spinlock_t irq_lock;
	wait_queue_head_t irq_queue;
	struct fasync_struct *async_queue;

	struct rtc_task *irq_task;
	spinlock_t irq_task_lock;
	int irq_freq;
	int max_user_freq;
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	struct work_struct uie_task;
	struct timer_list uie_timer;
	/* Those fields are protected by rtc->irq_lock */
	unsigned int oldsecs;
	unsigned int uie_irq_active:1;
	unsigned int stop_uie_polling:1;
	unsigned int uie_task_active:1;
	unsigned int uie_timer_active:1;
#endif
};
#define to_rtc_device(d) container_of(d, struct rtc_device, dev)

extern struct rtc_device *rtc_device_register(const char *name,
					struct device *dev,
					const struct rtc_class_ops *ops,
					struct module *owner);
extern void rtc_device_unregister(struct rtc_device *rtc);

extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
extern int rtc_read_alarm(struct rtc_device *rtc,
			struct rtc_wkalrm *alrm);
extern int rtc_set_alarm(struct rtc_device *rtc,
				struct rtc_wkalrm *alrm);
extern void rtc_update_irq(struct rtc_device *rtc,
			unsigned long num, unsigned long events);

extern struct rtc_device *rtc_class_open(char *name);
extern void rtc_class_close(struct rtc_device *rtc);

extern int rtc_irq_register(struct rtc_device *rtc,
				struct rtc_task *task);
extern void rtc_irq_unregister(struct rtc_device *rtc,
				struct rtc_task *task);
extern int rtc_irq_set_state(struct rtc_device *rtc,
				struct rtc_task *task, int enabled);
extern int rtc_irq_set_freq(struct rtc_device *rtc,
				struct rtc_task *task, int freq);
extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
						unsigned int enabled);

typedef struct rtc_task {
	void (*func)(void *private_data);
	void *private_data;
} rtc_task_t;

int rtc_register(rtc_task_t *task);
int rtc_unregister(rtc_task_t *task);
int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);

static inline bool is_leap_year(unsigned int year)
{
	return (!(year % 4) && (year % 100)) || !(year % 400);
}

#endif /* __KERNEL__ */

#endif /* _LINUX_RTC_H_ */