diff --git a/SConscript.firmware b/SConscript.firmware index 579bfc162c..3db755a130 100644 --- a/SConscript.firmware +++ b/SConscript.firmware @@ -211,7 +211,6 @@ SOURCE_MICROPYTHON = [ 'vendor/micropython/ports/stm32/gccollect.c', 'vendor/micropython/ports/stm32/gchelper.s', 'vendor/micropython/ports/stm32/pendsv.c', - 'vendor/micropython/ports/stm32/systick.c', ] SOURCE_MICROPYTHON_SPEED = [ @@ -269,6 +268,7 @@ SOURCE_TREZORHAL = [ 'embed/trezorhal/sbu.c', 'embed/trezorhal/sdcard.c', 'embed/trezorhal/stm32.c', + 'embed/trezorhal/systick.c', 'embed/trezorhal/touch.c', 'embed/trezorhal/usb.c', 'embed/trezorhal/usbd_conf.c', diff --git a/embed/trezorhal/systick.c b/embed/trezorhal/systick.c new file mode 100644 index 0000000000..c07d0fabce --- /dev/null +++ b/embed/trezorhal/systick.c @@ -0,0 +1,140 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2013, 2014 Damien P. George + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "py/runtime.h" +#include "py/mphal.h" +#include "irq.h" +#include "systick.h" +#include "pybthread.h" + +extern __IO uint32_t uwTick; + +// We provide our own version of HAL_Delay that calls __WFI while waiting, +// and works when interrupts are disabled. This function is intended to be +// used only by the ST HAL functions. +void HAL_Delay(uint32_t Delay) { + if (query_irq() == IRQ_STATE_ENABLED) { + // IRQs enabled, so can use systick counter to do the delay + uint32_t start = uwTick; + // Wraparound of tick is taken care of by 2's complement arithmetic. + while (uwTick - start < Delay) { + // Enter sleep mode, waiting for (at least) the SysTick interrupt. + __WFI(); + } + } else { + // IRQs disabled, use mp_hal_delay_ms routine. + mp_hal_delay_ms(Delay); + } +} + +// Core delay function that does an efficient sleep and may switch thread context. +// If IRQs are enabled then we must have the GIL. +void mp_hal_delay_ms(mp_uint_t Delay) { + if (query_irq() == IRQ_STATE_ENABLED) { + // IRQs enabled, so can use systick counter to do the delay + uint32_t start = uwTick; + // Wraparound of tick is taken care of by 2's complement arithmetic. + while (uwTick - start < Delay) { + // This macro will execute the necessary idle behaviour. It may + // raise an exception, switch threads or enter sleep mode (waiting for + // (at least) the SysTick interrupt). + MICROPY_EVENT_POLL_HOOK + } + } else { + // IRQs disabled, so need to use a busy loop for the delay. + // To prevent possible overflow of the counter we use a double loop. + const uint32_t count_1ms = HAL_RCC_GetSysClockFreq() / 4000; + for (int i = 0; i < Delay; i++) { + for (uint32_t count = 0; ++count <= count_1ms;) { + } + } + } +} + +// delay for given number of microseconds +void mp_hal_delay_us(mp_uint_t usec) { + if (query_irq() == IRQ_STATE_ENABLED) { + // IRQs enabled, so can use systick counter to do the delay + uint32_t start = mp_hal_ticks_us(); + while (mp_hal_ticks_us() - start < usec) { + } + } else { + // IRQs disabled, so need to use a busy loop for the delay + // sys freq is always a multiple of 2MHz, so division here won't lose precision + const uint32_t ucount = HAL_RCC_GetSysClockFreq() / 2000000 * usec / 2; + for (uint32_t count = 0; ++count <= ucount;) { + } + } +} + +bool sys_tick_has_passed(uint32_t start_tick, uint32_t delay_ms) { + return HAL_GetTick() - start_tick >= delay_ms; +} + +// waits until at least delay_ms milliseconds have passed from the sampling of +// startTick. Handles overflow properly. Assumes stc was taken from +// HAL_GetTick() some time before calling this function. +void sys_tick_wait_at_least(uint32_t start_tick, uint32_t delay_ms) { + while (!sys_tick_has_passed(start_tick, delay_ms)) { + __WFI(); // enter sleep mode, waiting for interrupt + } +} + +mp_uint_t mp_hal_ticks_ms(void) { + return uwTick; +} + +// The SysTick timer counts down at 168 MHz, so we can use that knowledge +// to grab a microsecond counter. +// +// We assume that HAL_GetTickis returns milliseconds. +mp_uint_t mp_hal_ticks_us(void) { + mp_uint_t irq_state = disable_irq(); + uint32_t counter = SysTick->VAL; + uint32_t milliseconds = HAL_GetTick(); + uint32_t status = SysTick->CTRL; + enable_irq(irq_state); + + // It's still possible for the countflag bit to get set if the counter was + // reloaded between reading VAL and reading CTRL. With interrupts disabled + // it definitely takes less than 50 HCLK cycles between reading VAL and + // reading CTRL, so the test (counter > 50) is to cover the case where VAL + // is +ve and very close to zero, and the COUNTFLAG bit is also set. + if ((status & SysTick_CTRL_COUNTFLAG_Msk) && counter > 50) { + // This means that the HW reloaded VAL between the time we read VAL and the + // time we read CTRL, which implies that there is an interrupt pending + // to increment the tick counter. + milliseconds++; + } + uint32_t load = SysTick->LOAD; + counter = load - counter; // Convert from decrementing to incrementing + + // ((load + 1) / 1000) is the number of counts per microsecond. + // + // counter / ((load + 1) / 1000) scales from the systick clock to microseconds + // and is the same thing as (counter * 1000) / (load + 1) + return milliseconds * 1000 + (counter * 1000) / (load + 1); +}