| Gabe Black | 3c7e939 | 2013-05-26 07:15:57 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This file is part of the coreboot project. |
| 3 | * |
| 4 | * Copyright (C) 2013 Google, Inc. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; version 2 of the License. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| Gabe Black | 3c7e939 | 2013-05-26 07:15:57 -0700 | [diff] [blame] | 14 | */ |
| 15 | |
| 16 | #include <stdint.h> |
| 17 | #include <delay.h> |
| 18 | #include <timer.h> |
| 19 | |
| 20 | #include "dmtimer.h" |
| 21 | |
| 22 | static struct monotonic_counter { |
| 23 | int initialized; |
| 24 | struct mono_time time; |
| 25 | uint64_t last_value; |
| 26 | } mono_counter; |
| 27 | |
| 28 | static const uint32_t clocks_per_usec = OSC_HZ/1000000; |
| 29 | |
| 30 | void timer_monotonic_get(struct mono_time *mt) |
| 31 | { |
| 32 | uint64_t current_tick; |
| 33 | uint64_t usecs_elapsed; |
| 34 | |
| 35 | if (!mono_counter.initialized) { |
| 36 | init_timer(); |
| 37 | mono_counter.last_value = dmtimer_raw_value(0); |
| 38 | mono_counter.initialized = 1; |
| 39 | } |
| 40 | |
| 41 | current_tick = dmtimer_raw_value(0); |
| 42 | usecs_elapsed = (current_tick - mono_counter.last_value) / |
| 43 | clocks_per_usec; |
| 44 | |
| 45 | /* Update current time and tick values only if a full tick occurred. */ |
| 46 | if (usecs_elapsed) { |
| 47 | mono_time_add_usecs(&mono_counter.time, usecs_elapsed); |
| 48 | mono_counter.last_value = current_tick; |
| 49 | } |
| 50 | |
| 51 | /* Save result. */ |
| 52 | *mt = mono_counter.time; |
| 53 | } |