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/*

 * Copyright (c) 2006 Ondrej Palkovsky

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup libc

 * @{

 */

/** @file

 */ 

#include <sys/time.h>

#include <unistd.h>

#include <ipc/ipc.h>

#include <stdio.h>

#include <arch/barrier.h>

#include <unistd.h>

#include <atomic.h>

#include <futex.h>

#include <sysinfo.h>

#include <ipc/services.h>

#include <sysinfo.h>

#include <as.h>

#include <ddi.h>

/* Pointers to public variables with time */

struct {

	volatile sysarg_t seconds1;

	volatile sysarg_t useconds;

	volatile sysarg_t seconds2;

} *ktime = NULL;

/** Add microseconds to given timeval.

 *

 * @param tv		Destination timeval.

 * @param usecs		Number of microseconds to add.

 */

void tv_add(struct timeval *tv, suseconds_t usecs)

{

	tv->tv_sec += usecs / 1000000;

	tv->tv_usec += usecs % 1000000;

	if (tv->tv_usec > 1000000) {

		tv->tv_sec++;

		tv->tv_usec -= 1000000;

	}

}

/** Subtract two timevals.

 *

 * @param tv1		First timeval.

 * @param tv2		Second timeval.

 *

 * @return		Return difference between tv1 and tv2 (tv1 - tv2) in

 * 			microseconds.

 */

suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)

{

	suseconds_t result;

	result = tv1->tv_usec - tv2->tv_usec;

	result += (tv1->tv_sec - tv2->tv_sec) * 1000000;

	return result;

}

/** Decide if one timeval is greater than the other.

 *

 * @param t1		First timeval.

 * @param t2		Second timeval.

 *

 * @return		Return true tv1 is greater than tv2. Otherwise return

 * 			false.

 */

int tv_gt(struct timeval *tv1, struct timeval *tv2)

{

	if (tv1->tv_sec > tv2->tv_sec)

		return 1;

	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)

		return 1;

	return 0;

}

/** Decide if one timeval is greater than or equal to the other.

 *

 * @param tv1		First timeval.

 * @param tv2		Second timeval.

 *

 * @return		Return true if tv1 is greater than or equal to tv2.

 * 			Otherwise return false.

 */

int tv_gteq(struct timeval *tv1, struct timeval *tv2)

{

	if (tv1->tv_sec > tv2->tv_sec)

		return 1;

	if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)

		return 1;

	return 0;

}

/** POSIX gettimeofday

 *

 * The time variables are memory mapped(RO) from kernel, which updates

 * them periodically. As it is impossible to read 2 values atomically, we

 * use a trick: First read a seconds, then read microseconds, then

 * read seconds again. If a second elapsed in the meantime, set it to zero. 

 * This provides assurance, that at least the

 * sequence of subsequent gettimeofday calls is ordered.

 */

int gettimeofday(struct timeval *tv, struct timezone *tz)

{

	void *mapping;

	sysarg_t s1, s2;

	sysarg_t rights;

	int res;

	if (!ktime) {

		mapping = as_get_mappable_page(PAGE_SIZE);

		/* Get the mapping of kernel clock */

		res = ipc_call_sync_3_2(PHONE_NS, IPC_M_AS_AREA_RECV,

		    (sysarg_t) mapping, PAGE_SIZE, SERVICE_MEM_REALTIME, NULL,

		    &rights);

		if (res) {

			printf("Failed to initialize timeofday memarea\n");

			_exit(1);

		}

		if (!(rights & AS_AREA_READ)) {

			printf("Received bad rights on time area: %X\n",

			    rights);

			as_area_destroy(mapping);

			_exit(1);

		}

		ktime = mapping;

	}

	if (tz) {

		tz->tz_minuteswest = 0;

		tz->tz_dsttime = DST_NONE;

	}

	s2 = ktime->seconds2;

	read_barrier();

	tv->tv_usec = ktime->useconds;

	read_barrier();

	s1 = ktime->seconds1;

	if (s1 != s2) {

		tv->tv_usec = 0;

		tv->tv_sec = s1 > s2 ? s1 : s2;

	} else

		tv->tv_sec = s1;

	return 0;

}

time_t time(time_t *tloc)

{

	struct timeval tv;

	if (gettimeofday(&tv, NULL))

		return (time_t) -1;

	if (tloc)

		*tloc = tv.tv_sec;

	return tv.tv_sec;

}

/** Wait unconditionally for specified number of microseconds */

int usleep(unsigned long usec)

{

	atomic_t futex = FUTEX_INITIALIZER;

	futex_initialize(&futex, 0);

	futex_down_timeout(&futex, usec, 0);

	return 0;

}

/** Wait unconditionally for specified number of seconds */

unsigned int sleep(unsigned int seconds)

{

	atomic_t futex = FUTEX_INITIALIZER;

	futex_initialize(&futex, 0);

	/* Sleep in 1000 second steps to support

	   full argument range */

	while (seconds > 0) {

		unsigned int period = (seconds > 1000) ? 1000 : seconds;

		futex_down_timeout(&futex, period * 1000000, 0);

		seconds -= period;

	}

	return 0;

}

/** @}

 */