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Marlin-Artillery-M600/Marlin/src/HAL/HAL_DUE/HAL_timers_Due.cpp
etagle 0566badcef Add memory barrier, optimal interrupt on-off
Disabling an ISR on ARM has 3 instructions of latency. A Memory barrier is REQUIRED to ensure proper and predictable disabling. Memory barriers are expensive, so avoid disabling if already disabled (See https://mcuoneclipse.com/2015/10/16/nvic-disabling-interrupts-on-arm-cortex-m-and-the-need-for-a-memory-barrier-instruction/)
2018-05-20 02:39:34 -05:00

158 lines
5.2 KiB
C++

/**
* Marlin 3D Printer Firmware
*
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
* Copyright (c) 2016 Bob Cousins bobcousins42@googlemail.com
* Copyright (c) 2015-2016 Nico Tonnhofer wurstnase.reprap@gmail.com
*
* 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 <http://www.gnu.org/licenses/>.
*
*/
/**
* Description: HAL for Arduino Due and compatible (SAM3X8E)
*
* For ARDUINO_ARCH_SAM
*/
#ifdef ARDUINO_ARCH_SAM
// --------------------------------------------------------------------------
// Includes
// --------------------------------------------------------------------------
#include "HAL.h"
#include "HAL_timers_Due.h"
// --------------------------------------------------------------------------
// Externals
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Local defines
// --------------------------------------------------------------------------
#define NUM_HARDWARE_TIMERS 9
#define PRESCALER 2
// --------------------------------------------------------------------------
// Types
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Public Variables
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Private Variables
// --------------------------------------------------------------------------
const tTimerConfig TimerConfig [NUM_HARDWARE_TIMERS] = {
{ TC0, 0, TC0_IRQn, 3}, // 0 - [servo timer5]
{ TC0, 1, TC1_IRQn, 0}, // 1
{ TC0, 2, TC2_IRQn, 0}, // 2
{ TC1, 0, TC3_IRQn, 2}, // 3 - stepper
{ TC1, 1, TC4_IRQn, 15}, // 4 - temperature
{ TC1, 2, TC5_IRQn, 3}, // 5 - [servo timer3]
{ TC2, 0, TC6_IRQn, 14}, // 6 - tone
{ TC2, 1, TC7_IRQn, 0}, // 7
{ TC2, 2, TC8_IRQn, 0}, // 8
};
// --------------------------------------------------------------------------
// Function prototypes
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Private functions
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// Public functions
// --------------------------------------------------------------------------
/*
Timer_clock1: Prescaler 2 -> 42MHz
Timer_clock2: Prescaler 8 -> 10.5MHz
Timer_clock3: Prescaler 32 -> 2.625MHz
Timer_clock4: Prescaler 128 -> 656.25kHz
*/
void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
Tc *tc = TimerConfig[timer_num].pTimerRegs;
IRQn_Type irq = TimerConfig[timer_num].IRQ_Id;
uint32_t channel = TimerConfig[timer_num].channel;
// Disable interrupt, just in case it was already enabled
NVIC_DisableIRQ(irq);
// We NEED memory barriers to ensure Interrupts are actually disabled!
// ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
__DSB();
__ISB();
// Disable timer interrupt
tc->TC_CHANNEL[channel].TC_IDR = TC_IDR_CPCS;
// Stop timer, just in case, to be able to reconfigure it
TC_Stop(tc, channel);
pmc_set_writeprotect(false);
pmc_enable_periph_clk((uint32_t)irq);
NVIC_SetPriority(irq, TimerConfig [timer_num].priority);
// wave mode, reset counter on match with RC,
TC_Configure(tc, channel, TC_CMR_WAVE | TC_CMR_WAVSEL_UP_RC | TC_CMR_TCCLKS_TIMER_CLOCK1);
// Set compare value
TC_SetRC(tc, channel, VARIANT_MCK / 2 / frequency);
// And start timer
TC_Start(tc, channel);
// enable interrupt on RC compare
tc->TC_CHANNEL[channel].TC_IER = TC_IER_CPCS;
// Finally, enable IRQ
NVIC_EnableIRQ(irq);
}
void HAL_timer_enable_interrupt(const uint8_t timer_num) {
IRQn_Type irq = TimerConfig[timer_num].IRQ_Id;
NVIC_EnableIRQ(irq);
}
void HAL_timer_disable_interrupt(const uint8_t timer_num) {
IRQn_Type irq = TimerConfig[timer_num].IRQ_Id;
NVIC_DisableIRQ(irq);
// We NEED memory barriers to ensure Interrupts are actually disabled!
// ( https://dzone.com/articles/nvic-disabling-interrupts-on-arm-cortex-m-and-the )
__DSB();
__ISB();
}
// missing from CMSIS: Check if interrupt is enabled or not
static bool NVIC_GetEnabledIRQ(IRQn_Type IRQn) {
return (NVIC->ISER[(uint32_t)(IRQn) >> 5] & (1 << ((uint32_t)(IRQn) & 0x1F))) != 0;
}
bool HAL_timer_interrupt_enabled(const uint8_t timer_num) {
IRQn_Type irq = TimerConfig[timer_num].IRQ_Id;
return NVIC_GetEnabledIRQ(irq);
}
#endif // ARDUINO_ARCH_SAM