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Diffstat (limited to 'Marlin/src/HAL/shared/Delay.h')
| -rw-r--r-- | Marlin/src/HAL/shared/Delay.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/Marlin/src/HAL/shared/Delay.h b/Marlin/src/HAL/shared/Delay.h new file mode 100644 index 0000000..a48f3f7 --- /dev/null +++ b/Marlin/src/HAL/shared/Delay.h @@ -0,0 +1,161 @@ +/** + * Marlin 3D Printer Firmware + * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin] + * + * Based on Sprinter and grbl. + * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + * + */ +#pragma once + +/** + * Busy wait delay cycles routines: + * + * DELAY_CYCLES(count): Delay execution in cycles + * DELAY_NS(count): Delay execution in nanoseconds + * DELAY_US(count): Delay execution in microseconds + */ + +#include "../../core/macros.h" + +#if defined(__arm__) || defined(__thumb__) + + #if __CORTEX_M == 7 + + // Cortex-M3 through M7 can use the cycle counter of the DWT unit + // https://www.anthonyvh.com/2017/05/18/cortex_m-cycle_counter/ + + FORCE_INLINE static void enableCycleCounter() { + CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk; + + #if __CORTEX_M == 7 + DWT->LAR = 0xC5ACCE55; // Unlock DWT on the M7 + #endif + + DWT->CYCCNT = 0; + DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk; + } + + FORCE_INLINE volatile uint32_t getCycleCount() { return DWT->CYCCNT; } + + FORCE_INLINE static void DELAY_CYCLES(const uint32_t x) { + const uint32_t endCycles = getCycleCount() + x; + while (PENDING(getCycleCount(), endCycles)) {} + } + + #else + + // https://blueprints.launchpad.net/gcc-arm-embedded/+spec/delay-cycles + + #define nop() __asm__ __volatile__("nop;\n\t":::) + + FORCE_INLINE static void __delay_4cycles(uint32_t cy) { // +1 cycle + #if ARCH_PIPELINE_RELOAD_CYCLES < 2 + #define EXTRA_NOP_CYCLES A("nop") + #else + #define EXTRA_NOP_CYCLES "" + #endif + + __asm__ __volatile__( + A(".syntax unified") // is to prevent CM0,CM1 non-unified syntax + L("1") + A("subs %[cnt],#1") + EXTRA_NOP_CYCLES + A("bne 1b") + : [cnt]"+r"(cy) // output: +r means input+output + : // input: + : "cc" // clobbers: + ); + } + + // Delay in cycles + FORCE_INLINE static void DELAY_CYCLES(uint32_t x) { + + if (__builtin_constant_p(x)) { + #define MAXNOPS 4 + + if (x <= (MAXNOPS)) { + switch (x) { case 4: nop(); case 3: nop(); case 2: nop(); case 1: nop(); } + } + else { // because of +1 cycle inside delay_4cycles + const uint32_t rem = (x - 1) % (MAXNOPS); + switch (rem) { case 3: nop(); case 2: nop(); case 1: nop(); } + if ((x = (x - 1) / (MAXNOPS))) + __delay_4cycles(x); // if need more then 4 nop loop is more optimal + } + #undef MAXNOPS + } + else if ((x >>= 2)) + __delay_4cycles(x); + } + #undef nop + + #endif + +#elif defined(__AVR__) + + #define nop() __asm__ __volatile__("nop;\n\t":::) + + FORCE_INLINE static void __delay_4cycles(uint8_t cy) { + __asm__ __volatile__( + L("1") + A("dec %[cnt]") + A("nop") + A("brne 1b") + : [cnt] "+r"(cy) // output: +r means input+output + : // input: + : "cc" // clobbers: + ); + } + + // Delay in cycles + FORCE_INLINE static void DELAY_CYCLES(uint16_t x) { + + if (__builtin_constant_p(x)) { + #define MAXNOPS 4 + + if (x <= (MAXNOPS)) { + switch (x) { case 4: nop(); case 3: nop(); case 2: nop(); case 1: nop(); } + } + else { + const uint32_t rem = (x) % (MAXNOPS); + switch (rem) { case 3: nop(); case 2: nop(); case 1: nop(); } + if ((x = (x) / (MAXNOPS))) + __delay_4cycles(x); // if need more then 4 nop loop is more optimal + } + + #undef MAXNOPS + } + else if ((x >>= 2)) + __delay_4cycles(x); + } + #undef nop + +#elif defined(__PLAT_LINUX__) || defined(ESP32) + + // specified inside platform + +#else + + #error "Unsupported MCU architecture" + +#endif + +// Delay in nanoseconds +#define DELAY_NS(x) DELAY_CYCLES((x) * ((F_CPU) / 1000000UL) / 1000UL) + +// Delay in microseconds +#define DELAY_US(x) DELAY_CYCLES((x) * ((F_CPU) / 1000000UL)) |