xref: /optee_os/core/include/drivers/rtc.h (revision 26899ca2e2f4cbe2b26643c60891f8596c715233)

/* SPDX-License-Identifier: BSD-2-Clause */
/*
 * Copyright 2022 Microchip.
 */

#ifndef __DRIVERS_RTC_H
#define __DRIVERS_RTC_H

#include <kernel/panic.h>
#include <tee_api_types.h>
#include <util.h>

/* The RTC allows to set/get offset for correction */
#define RTC_CORRECTION_FEATURE	BIT(0)

#define MS_PER_SEC		1000
#define MS_PER_MIN		(60 * MS_PER_SEC)
#define MS_PER_HOUR		(60 * MS_PER_MIN)
#define MS_PER_DAY		(24 * MS_PER_HOUR)

/*
 * struct optee_rtc_time - Time in Gregorian calendar
 *
 * @tm_year: Absolute year
 * @tm_mon: Month: 0=January, 1=February, ..., 11=December
 * @tm_mday: Month day start from 1
 * @tm_wday: Week day: 0=Sunday, 1=Monday, ..., 6=Saturday
 * @tm_hour: Hour in range [0 23]
 * @tm_min: Minute in range [0 59]
 * @tm_sec: Second in range [0 59]
 * @tm_ms: Millisecond in range [0 999] or 0 if no applicable
 */
struct optee_rtc_time {
	uint32_t tm_year;
	uint32_t tm_mon;
	uint32_t tm_mday;
	uint32_t tm_wday;
	uint32_t tm_hour;
	uint32_t tm_min;
	uint32_t tm_sec;
	uint32_t tm_ms;
};

struct rtc {
	const struct rtc_ops *ops;
	struct optee_rtc_time range_min;
	struct optee_rtc_time range_max;
};

/*
 * struct rtc_ops - The RTC device operations
 *
 * @get_time:	Get the RTC time.
 * @set_time:	Set the RTC time.
 * @get_offset:	Get the RTC offset.
 * @set_offset: Set the RTC offset
 */
struct rtc_ops {
	TEE_Result (*get_time)(struct rtc *rtc, struct optee_rtc_time *tm);
	TEE_Result (*set_time)(struct rtc *rtc, struct optee_rtc_time *tm);
	TEE_Result (*get_offset)(struct rtc *rtc, long *offset);
	TEE_Result (*set_offset)(struct rtc *rtc, long offset);
};

#ifdef CFG_DRIVERS_RTC
extern struct rtc *rtc_device;

/* Register a RTC device as the system RTC */
void rtc_register(struct rtc *rtc);

/**
 * rtc_is_a_leap_year() - Check if a year is a leap year
 * @year:	The year to check
 *
 * Return:	true if the year is a leap year, false otherwise
 */
bool rtc_is_a_leap_year(uint32_t year);

/**
 * rtc_get_month_days() - Get the number of days in a month
 * @month:	The month to know the number of days
 * @year:	The year of the month
 *
 * Return:	Number of days in the month
 */
uint8_t rtc_get_month_days(uint32_t month, uint32_t year);

/**
 * rtc_timecmp() - Compare two RTC time structures
 * @a:		First RTC time
 * @b:		Second RTC time
 *
 * Return a negative value if @a < @b
 * Return 0 if @a == @b
 * Return a positive value if @a > @b
 */
int rtc_timecmp(struct optee_rtc_time *a, struct optee_rtc_time *b);

/**
 * rtc_diff_calendar_ms() - Return the difference in milliseconds between
 * two times captures.
 * @ref1: First time capture
 * @ref2: Second time capture
 *
 * Return @ref1 - @ref2 in milliseconds or LLONG_MAX in case of overflow
 */
signed long long rtc_diff_calendar_ms(struct optee_rtc_time *ref1,
				      struct optee_rtc_time *ref2);

/**
 * rtc_diff_calendar_tick() - Return the difference in number of ticks between
 * two times captures.
 * @ref1: First time capture
 * @ref2: Second time capture
 * @tick_rate: Tick rate
 *
 * Return @ref1 - @ref2 in number of ticks. In case of tick computation
 * overflow, return LLONG_MAX
 */
signed long long rtc_diff_calendar_tick(struct optee_rtc_time *ref1,
					struct optee_rtc_time *ref2,
					unsigned long long tick_rate);

static inline TEE_Result rtc_get_info(uint64_t *features,
				      struct optee_rtc_time *range_min,
				      struct optee_rtc_time *range_max)
{
	if (!rtc_device)
		return TEE_ERROR_NOT_SUPPORTED;

	if (rtc_device->ops->set_offset)
		*features = RTC_CORRECTION_FEATURE;
	*range_min = rtc_device->range_min;
	*range_max = rtc_device->range_max;

	return TEE_SUCCESS;
}

static inline TEE_Result rtc_get_time(struct optee_rtc_time *tm)
{
	if (!rtc_device)
		return TEE_ERROR_NOT_SUPPORTED;

	return rtc_device->ops->get_time(rtc_device, tm);
}

static inline TEE_Result rtc_set_time(struct optee_rtc_time *tm)
{
	if (!rtc_device || !rtc_device->ops->set_time)
		return TEE_ERROR_NOT_SUPPORTED;

	return rtc_device->ops->set_time(rtc_device, tm);
}

static inline TEE_Result rtc_get_offset(long *offset)
{
	if (!rtc_device || !rtc_device->ops->get_offset)
		return TEE_ERROR_NOT_SUPPORTED;

	return rtc_device->ops->get_offset(rtc_device, offset);
}

static inline TEE_Result rtc_set_offset(long offset)
{
	if (!rtc_device || !rtc_device->ops->set_offset)
		return TEE_ERROR_NOT_SUPPORTED;

	return rtc_device->ops->set_offset(rtc_device, offset);
}

#else

static inline void rtc_register(struct rtc *rtc __unused) {}

static inline bool __noreturn rtc_is_a_leap_year(uint32_t year __unused)
{
	panic();
}

static inline uint8_t __noreturn rtc_get_month_days(uint32_t month __unused,
						    uint32_t year __unused)
{
	panic();
}

static inline int __noreturn rtc_timecmp(struct optee_rtc_time *a __unused,
					 struct optee_rtc_time *b __unused)
{
	panic();
}

static inline TEE_Result rtc_get_info(uint64_t *features __unused,
				      struct optee_rtc_time *range_min __unused,
				      struct optee_rtc_time *range_max __unused)
{
	return TEE_ERROR_NOT_SUPPORTED;
}

static inline TEE_Result rtc_get_time(struct optee_rtc_time *tm __unused)
{
	return TEE_ERROR_NOT_SUPPORTED;
}

static inline TEE_Result rtc_set_time(struct optee_rtc_time *tm __unused)
{
	return TEE_ERROR_NOT_SUPPORTED;
}

static inline TEE_Result rtc_get_offset(long *offset __unused)
{
	return TEE_ERROR_NOT_SUPPORTED;
}

static inline TEE_Result rtc_set_offset(long offset __unused)
{
	return TEE_ERROR_NOT_SUPPORTED;
}

static inline signed long long
rtc_diff_calendar_ms(struct optee_rtc_time *ref1 __unused,
		     struct optee_rtc_time *ref2 __unused)
{
	return LLONG_MAX;
}

static inline signed long long
rtc_diff_calendar_tick(struct optee_rtc_time *ref1 __unused,
		       struct optee_rtc_time *ref2 __unused,
		       unsigned long long tick_rate __unused)
{
	return LLONG_MAX;
}
#endif
#endif /* __DRIVERS_RTC_H */