/* SPDX-License-Identifier: MIT */
/* Copyright © 2025 Intel Corporation */

#ifndef __INTEL_DISPLAY_JIFFIES_H__
#define __INTEL_DISPLAY_JIFFIES_H__

#include <linux/jiffies.h>

static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
{
        unsigned long j = msecs_to_jiffies(m);

        return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
}

/*
 * If you need to wait X milliseconds between events A and B, but event B
 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 * when event A happened, then just before event B you call this function and
 * pass the timestamp as the first argument, and X as the second argument.
 */
static inline void
wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
{
        unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;

        /*
         * Don't re-read the value of "jiffies" every time since it may change
         * behind our back and break the math.
         */
        tmp_jiffies = jiffies;
        target_jiffies = timestamp_jiffies +
                         msecs_to_jiffies_timeout(to_wait_ms);

        if (time_after(target_jiffies, tmp_jiffies)) {
                remaining_jiffies = target_jiffies - tmp_jiffies;
                while (remaining_jiffies)
                        remaining_jiffies =
                            schedule_timeout_uninterruptible(remaining_jiffies);
        }
}

#endif /* __INTEL_DISPLAY_JIFFIES_H__ */