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/* SPDX-License-Identifier: GPL-2.0-only */
#include <timer.h>
#include <delay.h>
#include <cpu/power/spr.h>
/* Refer to hostboot/src/kernel/timemgr.C */
/* Time base frequency is 512 MHz so 512 ticks per usec */
#define TB_TICKS_PER_USEC 512
__weak void init_timer(void) { /* do nothing */ }
static struct monotonic_counter {
int initialized;
struct mono_time time;
uint64_t last_value;
} mono_counter;
void timer_monotonic_get(struct mono_time *mt)
{
uint64_t current_tick;
uint64_t usecs_elapsed;
if (!mono_counter.initialized) {
mono_counter.last_value = read_spr(SPR_TB);
mono_counter.initialized = 1;
}
current_tick = read_spr(SPR_TB);
usecs_elapsed = (current_tick - mono_counter.last_value) / TB_TICKS_PER_USEC;
/* Update current time and tick values only if a full tick occurred. */
if (usecs_elapsed) {
mono_time_add_usecs(&mono_counter.time, usecs_elapsed);
mono_counter.last_value = current_tick;
}
/* Save result. */
*mt = mono_counter.time;
}
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