ST-DEVKIT-LRWAN
Dependents: DISCO-L072CZ-LRWAN1-base
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Diff: Arduino-mbed-APIs/arduino-d21.cpp
- Revision:
- 77:7f227a4dffe6
- Child:
- 78:9d2cc07d9525
diff -r 79f8ca9c8025 -r 7f227a4dffe6 Arduino-mbed-APIs/arduino-d21.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Arduino-mbed-APIs/arduino-d21.cpp Mon Jul 31 16:11:17 2017 +0200 @@ -0,0 +1,398 @@ +/* + * The file is Licensed under the Apache License, Version 2.0 + * (c) 2017 Helmut Tschemernjak + * 30826 Garbsen (Hannover) Germany + */ + +#ifdef ARDUINO + +using namespace std; + +#include "arduino-mbed.h" +#include "arduino-util.h" + + + +#if defined(__SAMD21G18A__) || defined(__SAMD21J18A__) +/* + * __SAMD21J18A__ is the SamD21 Explained Board + * __SAMD21G18A__ is Genuino Zero-Board (compatible with the LoRa board) + */ + +/* + * see tcc.h is automatically included from: + * Arduino15/packages/arduino/tools/CMSIS-Atmel/1.1.0/CMSIS/ + * Device/ATMEL/samd21/include/component/tcc.h + * See also tcc.c (ASF/mbed, e.g. Tcc_get_count_value) + */ +static void initTimer(Tcc *t); +static uint32_t getTimerCount(Tcc *t); + +/* + * The Atmel D21 has three TCC timer, other models have more. + */ +const struct TCC_config { + Tcc *tcc_ptr; + IRQn_Type tcc_irq; + uint8_t nbits; +} TCC_data[] { + { TCC0, TCC0_IRQn, 24 }, + { TCC1, TCC1_IRQn, 24 }, + { TCC2, TCC2_IRQn, 16 }, + { NULL, (IRQn_Type)NULL, 0 } +}; + +/* + * We preferably use the TCC timers because it supports 24-bit counters + * versus TC Timer which supports only 8 or 16 bit counters only. + * TCC0/1/2 timer work on the D21 using Arduino Zero. + */ +#define USE_TCC_TIMEOUT 0 // 0=TCC0, 1=TTC1, 2=TTC2 (see TCC_data) +#define USE_TCC_TICKER 1 + + +/* + * every 21333 ns equals one tick (1/(48000000/1024)) // prescaler 1024, 48 MHz + * every 61035 ns equals one tick (1/(32768/2)) // prescaler 2, 32 kHz + * COUNT*DIVIDER*SECS until interrupt + * CPU 48 MHz = (65536*1024)/1.398636s + * RTC 32 kHz = (65536*2)/4.0s + */ +#define NS_PER_CLOCK_CPU 21333 // ns secs per clock +#define NS_PER_CLOCK_RTC 61035 // ns secs per clock + +#define NS_PER_CLOCK NS_PER_CLOCK_RTC + +/* ----------------- TICKER TIMER CODE ----------------------*/ + +/* + * The global ns_counter contains the time in ns from the last time + * the counter has been wrapped. It cannot be used directly because the + * current counter has to be added fore using it. Use instead + * ns_getTicker(), us_ ns_getTicker(), ms_getTicker() + */ + +uint64_t ticker_ns; +static bool initTickerDone = false; + +uint64_t ns_getTicker(void) +{ + Tcc *t = TCC_data[USE_TCC_TICKER].tcc_ptr; + if (!initTickerDone) { + initTimer(t); + initTickerDone = true; + + // set counter top to max 16 bit for testing + // t->PER.bit.PER = 0xffff; + // while (t->SYNCBUSY.bit.PER == 1); // wait for sync + + t->CTRLA.reg |= TCC_CTRLA_ENABLE ; // Enable TC + while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync + } + + /* + * if we are called from the interrupt level, the counter contains + * somehow wrong data, therfore we needs to read it twice. + * Another option was to add a little wait (loop 500x) + * in the TCC_TIMEOUT interrupt handler. + */ + if (SCB->ICSR & SCB_ICSR_VECTACTIVE_Msk) // check if we are in the interrupt + getTimerCount(t); + + uint64_t counter_us = (uint64_t)NS_PER_CLOCK * (uint64_t)getTimerCount(t); + uint64_t ns = ticker_ns + counter_us; + + return ns; +} + +#if USE_TCC_TICKER == 0 +void TCC0_Handler() +#elif USE_TCC_TICKER == 1 +void TCC1_Handler() +#elif USE_TCC_TICKER == 2 +void TCC2_Handler() +#endif +{ + Tcc *t = TCC_data[USE_TCC_TICKER].tcc_ptr; + /* + * Overflow means the timer top exeeded + */ + if (t->INTFLAG.bit.OVF == 1) { // A overflow caused the interrupt + t->INTFLAG.bit.OVF = 1; // writing a one clears the flag ovf flag + // ser->println("T_OVF"); + + /* + * reading the count once is needed, otherwise + * it will not wrap correct. + */ + getTimerCount(t); + + int bits = TCC_data[USE_TCC_TICKER].nbits; + int maxCounts = (uint32_t)(1<<bits); + + ticker_ns += (uint64_t)NS_PER_CLOCK * (uint64_t)maxCounts; + } + if (t->INTFLAG.bit.MC0 == 1) { // A compare to cc0 caused the interrupt + t->INTFLAG.bit.MC0 = 1; // writing a one clears the MCO (match capture) flag + // ser->println("T_MC0"); + } +} + +/* ----------------- SUPPORT CODE FOR TCC TIMERS----------------------*/ + +static bool initTimerDone = false; + +static void initTimer(Tcc *t) +{ + + /* + * enable clock for TCC, see gclk.h + * GCLK_CLKCTRL_GEN_GCLK0 for 48 Mhz CPU + * GCLK_CLKCTRL_GEN_GCLK1 for 32k extern crystal XOSC32K (ifdef CRYSTALLESS) + * GCLK_CLKCTRL_GEN_GCLK1 for 32k internal OSC32K + * see Arduino: arduino/hardware/samd/1.6.15/cores/arduino/startup.c + * Use TCC_CTRLA_PRESCALER_DIV1024 for for 48 Mhz clock + * Use TCC_CTRLA_PRESCALER_DIV2 for 32k clock + */ + if (t == TCC0 || t == TCC1) { + REG_GCLK_CLKCTRL = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK1 | GCLK_CLKCTRL_ID_TCC0_TCC1); + } else if (t == TCC2) { + REG_GCLK_CLKCTRL = (uint16_t) (GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK1 | GCLK_CLKCTRL_ID_TCC2_TC3_Val); + } + while (GCLK->STATUS.bit.SYNCBUSY == 1); // wait for sync + + t->CTRLA.reg &= ~TCC_CTRLA_ENABLE; // Disable TCC + while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync + + t->CTRLA.reg |= (TCC_CTRLA_PRESCALER_DIV2 | TCC_CTRLA_RUNSTDBY); // Set perscaler + + t->WAVE.reg |= TCC_WAVE_WAVEGEN_NFRQ; // Set wave form configuration + while (t->SYNCBUSY.bit.WAVE == 1); // wait for sync + + t->PER.bit.PER = 0xffffff; // set counter top to max 24 bit + while (t->SYNCBUSY.bit.PER == 1); // wait for sync + + // the compare counter TC->CC[0].reg will be set in the startTimer + // after the timeout calculation is known. + + // Interrupts + t->INTENSET.reg = 0; // disable all interrupts + t->INTENSET.bit.OVF = 1; // enable overfollow + t->INTENSET.bit.MC0 = 1; // enable compare match to CC0 + + const struct TCC_config *cp = &TCC_data[0]; + while (cp->tcc_ptr) { + if (cp->tcc_ptr == t) { + NVIC_EnableIRQ(cp->tcc_irq); // Enable InterruptVector + break; + } + cp++; + } +} + + +#if 0 +// Atmel ASF Code +static uint32_t getTimerCount(Tcc *t) +{ + uint32_t last_cmd; + /* Wait last command done */ + do { + while (t->SYNCBUSY.bit.CTRLB); /* Wait for sync */ + + last_cmd = t->CTRLBSET.reg & TCC_CTRLBSET_CMD_Msk; + if (TCC_CTRLBSET_CMD_NONE == last_cmd) { + /* Issue read command and break */ + t->CTRLBSET.bit.CMD = TCC_CTRLBSET_CMD_READSYNC_Val; + break; + } else if (TCC_CTRLBSET_CMD_READSYNC == last_cmd) { + /* Command have been issued */ + break; + } + } while (1); + + while (t->SYNCBUSY.bit.COUNT); /* Wait for sync */ + + return t->COUNT.reg; +} +#endif + + +static uint32_t getTimerCount(Tcc *t) +{ + + noInterrupts(); + + while (t->SYNCBUSY.bit.CTRLB); /* Wait for sync */ + + t->CTRLBSET.bit.CMD = TCC_CTRLBSET_CMD_READSYNC_Val; /* Issue read command and break */ + + while (t->SYNCBUSY.bit.COUNT); /* Wait for sync */ + + uint32_t count = t->COUNT.reg; + + interrupts(); + + return count; +} + + +Tcc *getTimeout_tcc(void) +{ + return TCC_data[USE_TCC_TIMEOUT].tcc_ptr; +} + + +void stopTimer(Tcc *t) +{ + t->CTRLA.reg &= ~TCC_CTRLA_ENABLE; // Disable TC + while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync +} + + +/* ----------------- TIMEOUT TIMER CODE ----------------------*/ + +void startTimer(Tcc *t, uint64_t delay_ns) +{ + if (!initTimerDone) { + initTimer(t); // initial setup with stopped timer + initTimerDone = true; + } + + stopTimer(t); // avoid timer interrupts while calculating + + /* + * every 21333 ns equals one tick (1/(48000000/1024)) + * COUNT*DIVIDER*SECS until interrupt + * 48 Mhz = (65536*1024)/1.398636s + */ + uint64_t nclocks = (uint64_t)delay_ns; + nclocks /= (uint64_t)NS_PER_CLOCK; + int nCounts = nclocks; + + int bits = TCC_data[USE_TCC_TIMEOUT].nbits; + int maxCounts = (uint32_t)(1<<bits)-1; + + if (nCounts > maxCounts) // if count exceeds timer capacity + nCounts = maxCounts; // set the largest posible count. + if (nCounts <= 0) + nCounts = 1; + t->CC[0].bit.CC = nCounts; + while (t->SYNCBUSY.bit.CC0 == 1); // wait for sync + + t->CTRLA.reg |= TCC_CTRLA_ENABLE ; // Enable TC + while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync +#if 0 + ser->print(ms_getTicker(), DEC); + ser->print(" startTimer: nCounts="); + ser->println(nCounts, DEC); +#endif +} + + +#if USE_TCC_TIMEOUT == 0 +void TCC0_Handler() +#elif USE_TCC_TIMEOUT == 1 +void TCC1_Handler() +#elif USE_TCC_TIMEOUT == 2 +void TCC2_Handler() +#endif +{ + Tcc *t = TCC_data[USE_TCC_TIMEOUT].tcc_ptr; + uint64_t nsecs = ns_getTicker(); + + /* + * Overflow means the max timer exeeded, we need restart the timer + * Interrupts and + */ + if (t->INTFLAG.bit.OVF == 1) { // A overflow caused the interrupt + t->INTFLAG.bit.OVF = 1; // writing a one clears the flag ovf flag + } + + if (t->INTFLAG.bit.MC0 == 1) { // A compare to cc0 caused the interrupt + //ser->print("MC0\r\n"); + t->INTFLAG.bit.MC0 = 1; // writing a one clears the MCO (match capture) flag + } + + t->CTRLA.reg &= ~TCC_CTRLA_ENABLE; // Disable TC + while (t->SYNCBUSY.bit.ENABLE == 1); // wait for sync + + for (int i = 0; i < MAX_TIMEOUTS-1; i++) { + struct TimeoutVector *tvp = &TimeOuts[i]; + if (tvp->timer && nsecs >= tvp->timer->_timeout) { + Timeout *saveTimer = tvp->timer; + tvp->timer = NULL; + Timeout::_irq_handler(saveTimer); + } + } + /* + * we need to restart the timer for remaining interrupts + * Another reason is that we stopped this counter, in case there are + * remaining counts, we need to re-schedule the counter. + */ + Timeout::restart(); +} + + +/* ----------------- D21 sleep() and deepsleep() code ----------------------*/ + +void sleep(void) +{ + /* + * If we use the native USB port our Serial is SerialUSB + * and if the SerialUSB and connected we should + * not enter into sleep mode because this kills the Arduino USB emulation + */ + if (ser && ser == (Stream *)&SerialUSB) { + __WFI(); + return; + // USB->CTRLA.bit.ENABLE = 0; + // USB->HOST.CTRLA.reg = 0; + // USB->HOST.CTRLA.bit.ENABLE &= USB_CTRLA_ENABLE; + } + + +#if 1 // (SAMD20 || SAMD21) + /* Errata: Make sure that the Flash does not power all the way down + * when in sleep mode. */ + NVMCTRL->CTRLB.bit.SLEEPPRM = NVMCTRL_CTRLB_SLEEPPRM_DISABLED_Val; +#endif + uint32_t saved_ms = ms_getTicker(); + SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; // disbale SysTick + + SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk; // clear deep sleep + PM->SLEEP.reg = 2; // SYSTEM_SLEEPMODE_IDLE_2 IDLE 2 sleep mode. + + __DSB(); // ensures the completion of memory accesses + __WFI(); // wait for interrupt + + int count = ms_getTicker() - saved_ms; + if (count > 0) { // update the Arduino Systicks + for (int i = 0; i < count; i++) { + SysTick_Handler(); + } + } + SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; // enable SysTick +} + +void deepsleep(void) +{ +#if 1 // (SAMD20 || SAMD21) + /* Errata: Make sure that the Flash does not power all the way down + * when in sleep mode. */ + NVMCTRL->CTRLB.bit.SLEEPPRM = NVMCTRL_CTRLB_SLEEPPRM_DISABLED_Val; +#endif + + SysTick->CTRL &= ~SysTick_CTRL_ENABLE_Msk; // disbale SysTick + + SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk; // standby mode + + __DSB(); // ensures the completion of memory accesses + __WFI(); // wait for interrupt + + SysTick->CTRL |= SysTick_CTRL_ENABLE_Msk; // enable SysTick +} + +#endif // D21 TCC Timer, sleep, etc- + +#endif // ARDUINO