From 3f5dc472965e6a5b8efe60e33c7b6c2d18d92008 Mon Sep 17 00:00:00 2001 From: Stefan Kerkmann Date: Mon, 11 Jul 2022 15:17:05 +0200 Subject: [Core] Use polled waiting on ChibiOS platforms that support it (#17607) * Use polled waiting on platforms that support it Due to context switching overhead waiting a very short amount of time on a sleeping thread is often not accurate and in fact not usable for timing critical usage i.e. in a driver. Thus we use polled waiting for ranges in the us range on platforms that support it instead. The fallback is the thread sleeping mechanism. This includes: * ARM platforms with CYCCNT register (ARMv7, ARMv8) this is incremented at CPU clock frequency * GD32VF103 RISC-V port with CSR_MCYCLE register this is incremented at CPU clock frequency * RP2040 ARMv6 port which uses the integrated timer peripheral which is incremented with a fixed 1MHz frequency * Use wait_us() instead of chSysPolledDelayX ...as it is powered by busy waiting now. * Add chibios waiting methods test bench --- .../onekey/keymaps/chibios_waiting_test/config.h | 12 ++++++ .../onekey/keymaps/chibios_waiting_test/keymap.c | 47 ++++++++++++++++++++++ 2 files changed, 59 insertions(+) create mode 100644 keyboards/handwired/onekey/keymaps/chibios_waiting_test/config.h create mode 100644 keyboards/handwired/onekey/keymaps/chibios_waiting_test/keymap.c (limited to 'keyboards/handwired/onekey/keymaps/chibios_waiting_test') diff --git a/keyboards/handwired/onekey/keymaps/chibios_waiting_test/config.h b/keyboards/handwired/onekey/keymaps/chibios_waiting_test/config.h new file mode 100644 index 0000000000..0c75fa3044 --- /dev/null +++ b/keyboards/handwired/onekey/keymaps/chibios_waiting_test/config.h @@ -0,0 +1,12 @@ +// Copyright 2022 Stefan Kerkmann +// SPDX-License-Identifier: GPL-2.0-or-later + +#pragma once + +#if !defined(QMK_WAITING_TEST_BUSY_PIN) +# define QMK_WAITING_TEST_BUSY_PIN A8 +#endif + +#if !defined(QMK_WAITING_TEST_YIELD_PIN) +# define QMK_WAITING_TEST_YIELD_PIN A9 +#endif diff --git a/keyboards/handwired/onekey/keymaps/chibios_waiting_test/keymap.c b/keyboards/handwired/onekey/keymaps/chibios_waiting_test/keymap.c new file mode 100644 index 0000000000..ecf67d3b3c --- /dev/null +++ b/keyboards/handwired/onekey/keymaps/chibios_waiting_test/keymap.c @@ -0,0 +1,47 @@ +// Copyright 2022 Stefan Kerkmann +// SPDX-License-Identifier: GPL-2.0-or-later + +#include QMK_KEYBOARD_H + +const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {LAYOUT_ortho_1x1(KC_A)}; + +#if defined(__AVR__) +# pragma message "AVR uses polled waiting by default, running theses tests will not show any difference" +static inline void chThdSleepMicroseconds(uint32_t us) { + wait_us(us); +} +#endif + +void keyboard_post_init_user(void) { + setPinOutput(QMK_WAITING_TEST_BUSY_PIN); + setPinOutput(QMK_WAITING_TEST_YIELD_PIN); +} + +static inline void wait_us_polling_with_strobe(uint32_t us) { + writePinHigh(QMK_WAITING_TEST_BUSY_PIN); + wait_us(us); + writePinLow(QMK_WAITING_TEST_BUSY_PIN); +} + +static inline void wait_us_yield_with_strobe(uint32_t us) { + writePinHigh(QMK_WAITING_TEST_YIELD_PIN); + chThdSleepMicroseconds(us); + writePinLow(QMK_WAITING_TEST_YIELD_PIN); +} + +static const uint32_t waiting_values[] = {0, 1, 5, 10, 25, 50, 100, 150, 200, 500, 1000}; + +void housekeeping_task_user(void) { + static uint32_t last_bench = 0; + if (timer_elapsed32(last_bench) > 500) { + for (int i = 0; i < (sizeof(waiting_values) / sizeof(waiting_values[0])); i++) { + wait_us_polling_with_strobe(waiting_values[i]); + wait_us(10); + } + for (int i = 0; i < (sizeof(waiting_values) / sizeof(waiting_values[0])); i++) { + wait_us_yield_with_strobe(waiting_values[i]); + wait_us(10); + } + last_bench = timer_read32(); + } +} -- cgit v1.2.3