| /* 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; |
| } |