/**

 * @file clockadj.h

 * @brief Wraps clock_adjtime functionality.

 * @note Copyright (C) 2013 Miroslav Lichvar <mlichvar@redhat.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifndef HAVE_CLOCKADJ_H

#define HAVE_CLOCKADJ_H

#include <inttypes.h>

#include <time.h>

/**

 * Initialize state needed when adjusting or reading the clock.

 * @param clkid A clock ID obtained using phc_open() or CLOCK_REALTIME.

 */

void clockadj_init(clockid_t clkid);

/**

 * Set clock's frequency offset.

 * @param clkid A clock ID obtained using phc_open() or CLOCK_REALTIME.

 * @param freq  The frequency offset in parts per billion (ppb).

 */

void clockadj_set_freq(clockid_t clkid, double freq);

/**

 * Read clock's frequency offset.

 * @param clkid A clock ID obtained using phc_open() or CLOCK_REALTIME.

 * @return      The frequency offset in parts per billion (ppb).

 */

double clockadj_get_freq(clockid_t clkid);

/**

 * Step clock's time.

 * @param clkid A clock ID obtained using phc_open() or CLOCK_REALTIME.

 * @param step  The time step in nanoseconds.

 */

void clockadj_step(clockid_t clkid, int64_t step);

/**

 * Set the system clock to insert/delete leap second at midnight.

 * @param leap  +1 to insert leap second, -1 to delete leap second,

 *              0 to reset the leap state.

 */

void sysclk_set_leap(int leap);

/**

 * Set the TAI offset of the system clock to have correct CLOCK_TAI.

 * @param offset The TAI-UTC offset in seconds.

 */

void sysclk_set_tai_offset(int offset);

/**

 * Read maximum frequency adjustment of the system clock (CLOCK_REALTIME).

 * @return The maximum frequency adjustment in parts per billion (ppb).

 */

int sysclk_max_freq(void);

/**

 * Mark the system clock as synchronized to let the kernel synchronize

 * the real-time clock (RTC) to it.

 */

void sysclk_set_sync(void);

#endif