timer.h (2510B)
1 /* 2 Copyright 2011 Jun Wako <wakojun@gmail.com> 3 Copyright 2021 Simon Arlott 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation, either version 2 of the License, or 8 (at your option) any later version. 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. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #pragma once 20 21 #if __has_include_next("_timer.h") 22 # include_next "_timer.h" /* Include the platform's _timer.h */ 23 #endif 24 25 #include <stdint.h> 26 27 #define TIMER_DIFF_8(a, b) (uint8_t)((a) - (b)) 28 #define TIMER_DIFF_16(a, b) (uint16_t)((a) - (b)) 29 #define TIMER_DIFF_32(a, b) (uint32_t)((a) - (b)) 30 #define TIMER_DIFF_RAW(a, b) TIMER_DIFF_8(a, b) 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 extern volatile uint32_t timer_count; 37 38 void timer_init(void); 39 void timer_clear(void); 40 void timer_save(void); 41 void timer_restore(void); 42 uint16_t timer_read(void); 43 uint32_t timer_read32(void); 44 uint16_t timer_elapsed(uint16_t last); 45 uint32_t timer_elapsed32(uint32_t last); 46 47 // Utility functions to check if a future time has expired & autmatically handle time wrapping if checked / reset frequently (half of max value) 48 #define timer_expired(current, future) ((uint16_t)(current - future) < UINT16_MAX / 2) 49 #define timer_expired32(current, future) ((uint32_t)(current - future) < UINT32_MAX / 2) 50 51 // Use an appropriate timer integer size based on architecture (16-bit will overflow sooner) 52 #if FAST_TIMER_T_SIZE < 32 53 # define TIMER_DIFF_FAST(a, b) TIMER_DIFF_16(a, b) 54 # define timer_expired_fast(current, future) timer_expired(current, future) 55 typedef uint16_t fast_timer_t; 56 fast_timer_t inline timer_read_fast(void) { 57 return timer_read(); 58 } 59 fast_timer_t inline timer_elapsed_fast(fast_timer_t last) { 60 return timer_elapsed(last); 61 } 62 #else 63 # define TIMER_DIFF_FAST(a, b) TIMER_DIFF_32(a, b) 64 # define timer_expired_fast(current, future) timer_expired32(current, future) 65 typedef uint32_t fast_timer_t; 66 fast_timer_t inline timer_read_fast(void) { 67 return timer_read32(); 68 } 69 fast_timer_t inline timer_elapsed_fast(fast_timer_t last) { 70 return timer_elapsed32(last); 71 } 72 #endif 73 74 #ifdef __cplusplus 75 } 76 #endif