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Diff: WS2811.cpp
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diff -r 000000000000 -r a8535703f23b WS2811.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/WS2811.cpp Sat Jan 04 00:40:08 2014 +0000 @@ -0,0 +1,399 @@ +// 800 KHz WS2811 driver driving potentially many LED strings. +// Uses 3-phase DMA +// 16K SRAM less stack, etc. +// +// Per LED: 3 bytes (malloc'd) for RGB data +// +// Per LED strip / per LED +// 96 bytes (static) for bit data +// + 96 bytes (static) for ones data +// = 192 bytes +// +// 40 LEDs max per string = 7680 bytes static +// +// 40 LEDs: 7680 + 40*3 = 7800 bytes +// 80 LEDs: 7680 + 80*3 = 7920 bytes + +#include "MKL25Z4.h" +#include "LedStrip.h" +#include "WS2811.h" + +// +// Configuration +// + +// Define MONITOR_TPM0_PWM as non-zero to monitor PWM timing on PTD0 and PTD1 +// PTD0 TPM0/CH0 PWM_1 J2/06 +// PTD1 TPM0/CH1 PWM_2 J2/12 (also LED_BLUE) +#define MONITOR_TPM0_PWM 0 + +// define DEBUG_PIN to identify a pin in PORTD used for debug output +// #define DEBUG_PIN 4 /* PTD4 debugOut */ + +#ifdef DEBUG_PIN +#define DEBUG 1 +#endif + +#if DEBUG +#define DEBUG_MASK (1<<DEBUG_PIN) +#define RESET_DEBUG (IO_GPIO->PDOR &= ~DEBUG_MASK) +#define SET_DEBUG (IO_GPIO->PDOR |= DEBUG_MASK) +#else +#define DEBUG_MASK 0 +#define RESET_DEBUG (void)0 +#define SET_DEBUG (void)0 +#endif + +static PORT_Type volatile * const IO_PORT = PORTD; +static GPIO_Type volatile * const IO_GPIO = PTD; + +// 48 MHz clock, no prescaling. +#define NSEC_TO_TICKS(nsec) ((nsec)*48/1000) +#define USEC_TO_TICKS(usec) ((usec)*48) +static const uint32_t CLK_NSEC = 1250; +static const uint32_t tpm_period = NSEC_TO_TICKS(CLK_NSEC); +static const uint32_t tpm_p0_period = NSEC_TO_TICKS(250); +static const uint32_t tpm_p1_period = NSEC_TO_TICKS(650); +static const uint32_t guardtime_period = USEC_TO_TICKS(55); // guardtime minimum 50 usec. + +enum DMA_MUX_SRC { + DMA_MUX_SRC_TPM0_CH_0 = 24, + DMA_MUX_SRC_TPM0_CH_1, + DMA_MUX_SRC_TPM0_Overflow = 54, +}; + +enum DMA_CHAN { + DMA_CHAN_START = 0, + DMA_CHAN_0_LOW = 1, + DMA_CHAN_1_LOW = 2, + N_DMA_CHANNELS +}; + +volatile bool WS2811::dma_done = true; + +// class static +bool WS2811::initialized = false; + +// class static +uint32_t WS2811::enabledPins = 0; + +#define WORD_ALIGNED __attribute__ ((aligned(4))) + +#define DMA_LEADING_ZEROS 2 +#define BITS_PER_RGB 24 +#define DMA_TRAILING_ZEROS 1 + +static struct { + uint32_t start_t1_low[ DMA_LEADING_ZEROS ]; + uint32_t dmaWords[ BITS_PER_RGB * MAX_LEDS_PER_STRIP ]; + uint32_t trailing_zeros_1[ DMA_TRAILING_ZEROS ]; + + uint32_t start_t0_high[ DMA_LEADING_ZEROS - 1 ]; + uint32_t allOnes[ BITS_PER_RGB * MAX_LEDS_PER_STRIP ]; + uint32_t trailing_zeros_2[ DMA_TRAILING_ZEROS + 1 ]; +} dmaData WORD_ALIGNED; + +// class static +void WS2811::hw_init() +{ + if (initialized) return; + + dma_data_init(); + clock_init(); + dma_init(); + io_init(); + tpm_init(); + + initialized = true; + + SET_DEBUG; + RESET_DEBUG; +} + +// class static +void WS2811::dma_data_init() +{ + memset(dmaData.allOnes, 0xFF, sizeof(dmaData.allOnes)); + +#if DEBUG + for (unsigned i = 0; i < BITS_PER_RGB * MAX_LEDS_PER_STRIP; i++) + dmaData.dmaWords[i] = DEBUG_MASK; +#endif +} + +// class static + +/// Enable PORTD, DMA and TPM0 clocking +void WS2811::clock_init() +{ + SIM->SCGC5 |= SIM_SCGC5_PORTD_MASK; + SIM->SCGC6 |= SIM_SCGC6_DMAMUX_MASK | SIM_SCGC6_TPM0_MASK; // Enable clock to DMA mux and TPM0 + SIM->SCGC7 |= SIM_SCGC7_DMA_MASK; // Enable clock to DMA + + SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: MCGFLLCLK or MCGPLLCLK +} + +// class static + +/// Configure GPIO output pins +void WS2811::io_init() +{ + uint32_t m = 1; + for (uint32_t i = 0; i < 32; i++) { + // set up each pin + if (m & enabledPins) { + IO_PORT->PCR[i] = PORT_PCR_MUX(1) // GPIO + | PORT_PCR_DSE_MASK; // high drive strength + } + m <<= 1; + } + + IO_GPIO->PDDR |= enabledPins; // set as outputs + +#if MONITOR_TPM0_PWM + // PTD0 CH0 monitor: TPM0, high drive strength + IO_PORT->PCR[0] = PORT_PCR_MUX(4) | PORT_PCR_DSE_MASK; + // PTD1 CH1 monitor: TPM0, high drive strength + IO_PORT->PCR[1] = PORT_PCR_MUX(4) | PORT_PCR_DSE_MASK; + IO_GPIO->PDDR |= 3; // set as outputs + IO_GPIO->PDOR &= ~(enabledPins | 3); // initially low +#else + IO_GPIO->PDOR &= ~enabledPins; // initially low +#endif + +#if DEBUG + IO_PORT->PCR[DEBUG_PIN] = PORT_PCR_MUX(1) | PORT_PCR_DSE_MASK; + IO_GPIO->PDDR |= DEBUG_MASK; + IO_GPIO->PDOR &= ~DEBUG_MASK; +#endif +} + +// class static + +/// Configure DMA and DMAMUX +void WS2811::dma_init() +{ + // reset DMAMUX + DMAMUX0->CHCFG[DMA_CHAN_START] = 0; + DMAMUX0->CHCFG[DMA_CHAN_0_LOW] = 0; + DMAMUX0->CHCFG[DMA_CHAN_1_LOW] = 0; + + // wire our DMA event sources into the first three DMA channels + // t=0: all enabled outputs go high on TPM0 overflow + DMAMUX0->CHCFG[DMA_CHAN_START] = DMAMUX_CHCFG_ENBL_MASK | DMAMUX_CHCFG_SOURCE(DMA_MUX_SRC_TPM0_Overflow); + // t=tpm_p0_period: all of the 0 bits go low. + DMAMUX0->CHCFG[DMA_CHAN_0_LOW] = DMAMUX_CHCFG_ENBL_MASK | DMAMUX_CHCFG_SOURCE(DMA_MUX_SRC_TPM0_CH_0); + // t=tpm_p1_period: all outputs go low. + DMAMUX0->CHCFG[DMA_CHAN_1_LOW] = DMAMUX_CHCFG_ENBL_MASK | DMAMUX_CHCFG_SOURCE(DMA_MUX_SRC_TPM0_CH_1); + + NVIC_SetVector(DMA0_IRQn, (uint32_t)&DMA0_IRQHandler); + NVIC_EnableIRQ(DMA0_IRQn); +} + +// class static + +/// Configure TPM0 to do two different PWM periods at 800kHz rate +void WS2811::tpm_init() +{ + // set up TPM0 for proper period (800 kHz = 1.25 usec ±600nsec) + TPM_Type volatile *tpm = TPM0; + tpm->SC = TPM_SC_DMA_MASK // enable DMA + | TPM_SC_TOF_MASK // reset TOF flag if set + | TPM_SC_CMOD(0) // disable clocks + | TPM_SC_PS(0); // 48MHz / 1 = 48MHz clock + tpm->MOD = tpm_period - 1; // 48MHz / 800kHz + + // No Interrupts; High True pulses on Edge Aligned PWM + tpm->CONTROLS[0].CnSC = TPM_CnSC_MSB_MASK | TPM_CnSC_ELSB_MASK | TPM_CnSC_DMA_MASK; + tpm->CONTROLS[1].CnSC = TPM_CnSC_MSB_MASK | TPM_CnSC_ELSB_MASK | TPM_CnSC_DMA_MASK; + + // set TPM0 channel 0 for 0.35 usec (±150nsec) (0 code) + // 1.25 usec * 1/3 = 417 nsec + tpm->CONTROLS[0].CnV = tpm_p0_period; + + // set TPM0 channel 1 for 0.7 usec (±150nsec) (1 code) + // 1.25 usec * 2/3 = 833 nsec + tpm->CONTROLS[1].CnV = tpm_p1_period; + + NVIC_SetVector(TPM0_IRQn, (uint32_t)&TPM0_IRQHandler); + NVIC_EnableIRQ(TPM0_IRQn); +} + +WS2811::WS2811(unsigned n, unsigned pinNumber) + : LedStrip(n) + , pinMask(1U << pinNumber) +{ + enabledPins |= pinMask; + initialized = false; +} + +// class static +void WS2811::startDMA() +{ + hw_init(); + + wait_for_dma_done(); + dma_done = false; + + DMA_Type volatile * dma = DMA0; + TPM_Type volatile *tpm = TPM0; + uint32_t nBytes = sizeof(dmaData.start_t1_low) + + sizeof(dmaData.dmaWords) + + sizeof(dmaData.trailing_zeros_1); + + tpm->SC = TPM_SC_DMA_MASK // enable DMA + | TPM_SC_TOF_MASK // reset TOF flag if set + | TPM_SC_CMOD(0) // disable clocks + | TPM_SC_PS(0); // 48MHz / 1 = 48MHz clock + tpm->MOD = tpm_period - 1; // 48MHz / 800kHz + + tpm->CNT = tpm_p0_period - 2 ; + tpm->STATUS = 0xFFFFFFFF; + + dma->DMA[DMA_CHAN_START].DSR_BCR = DMA_DSR_BCR_DONE_MASK; // clear/reset DMA status + dma->DMA[DMA_CHAN_0_LOW].DSR_BCR = DMA_DSR_BCR_DONE_MASK; // clear/reset DMA status + dma->DMA[DMA_CHAN_1_LOW].DSR_BCR = DMA_DSR_BCR_DONE_MASK; // clear/reset DMA status + + // t=0: all outputs go high + // triggered by TPM0_Overflow + // source is one word of 0 then 24 x 0xffffffff, then another 0 word + dma->DMA[DMA_CHAN_START].SAR = (uint32_t)(void*)dmaData.start_t0_high; + dma->DMA[DMA_CHAN_START].DSR_BCR = DMA_DSR_BCR_BCR_MASK & nBytes; // length of transfer in bytes + + // t=tpm_p0_period: some outputs (the 0 bits) go low. + // Triggered by TPM0_CH0 + // Start 2 words before the actual data to avoid garbage pulses. + dma->DMA[DMA_CHAN_0_LOW].SAR = (uint32_t)(void*)dmaData.start_t1_low; // set source address + dma->DMA[DMA_CHAN_0_LOW].DSR_BCR = DMA_DSR_BCR_BCR_MASK & nBytes; // length of transfer in bytes + + // t=tpm_p1_period: all outputs go low. + // Triggered by TPM0_CH1 + // source is constant 0x00000000 (first word of dmaWords) + dma->DMA[DMA_CHAN_1_LOW].SAR = (uint32_t)(void*)dmaData.start_t1_low; // set source address + dma->DMA[DMA_CHAN_1_LOW].DSR_BCR = DMA_DSR_BCR_BCR_MASK & nBytes; // length of transfer in bytes + + dma->DMA[DMA_CHAN_0_LOW].DAR + = dma->DMA[DMA_CHAN_1_LOW].DAR + = dma->DMA[DMA_CHAN_START].DAR + = (uint32_t)(void*)&IO_GPIO->PDOR; + + SET_DEBUG; + + dma->DMA[DMA_CHAN_0_LOW].DCR = DMA_DCR_EINT_MASK // enable interrupt on end of transfer + | DMA_DCR_ERQ_MASK + | DMA_DCR_D_REQ_MASK // clear ERQ on end of transfer + | DMA_DCR_SINC_MASK // increment source each transfer + | DMA_DCR_CS_MASK + | DMA_DCR_SSIZE(0) // 32-bit source transfers + | DMA_DCR_DSIZE(0); // 32-bit destination transfers + + dma->DMA[DMA_CHAN_1_LOW].DCR = DMA_DCR_EINT_MASK // enable interrupt on end of transfer + | DMA_DCR_ERQ_MASK + | DMA_DCR_D_REQ_MASK // clear ERQ on end of transfer + | DMA_DCR_CS_MASK + | DMA_DCR_SSIZE(0) // 32-bit source transfers + | DMA_DCR_DSIZE(0); // 32-bit destination transfers + + dma->DMA[DMA_CHAN_START].DCR = DMA_DCR_EINT_MASK // enable interrupt on end of transfer + | DMA_DCR_ERQ_MASK + | DMA_DCR_D_REQ_MASK // clear ERQ on end of transfer + | DMA_DCR_SINC_MASK // increment source each transfer + | DMA_DCR_CS_MASK + | DMA_DCR_SSIZE(0) // 32-bit source transfers + | DMA_DCR_DSIZE(0); + + tpm->SC |= TPM_SC_CMOD(1); // enable internal clocking +} + +void WS2811::writePixel(unsigned n, uint8_t *p) +{ + uint32_t *dest = dmaData.dmaWords + n * BITS_PER_RGB; + writeByte(*p++, pinMask, dest + 0); // G + writeByte(*p++, pinMask, dest + 8); // R + writeByte(*p, pinMask, dest + 16); // B +} + +// class static +void WS2811::writeByte(uint8_t byte, uint32_t mask, uint32_t *dest) +{ + for (uint8_t bm = 0x80; bm; bm >>= 1) { + // MSBit first + if (byte & bm) + *dest |= mask; + else + *dest &= ~mask; + dest++; + } +} + +void WS2811::begin() +{ + blank(); + show(); +} + +void WS2811::blank() +{ + memset(pixels, 0x00, numPixelBytes()); + +#if DEBUG + for (unsigned i = DMA_LEADING_ZEROS; i < DMA_LEADING_ZEROS + BITS_PER_RGB; i++) + dmaData.dmaWords[i] = DEBUG_MASK; +#else + memset(dmaData.dmaWords, 0x00, sizeof(dmaData.dmaWords)); +#endif +} + +void WS2811::show() +{ + + uint16_t i, n = numPixels(); // 3 bytes per LED + uint8_t *p = pixels; + + for (i=0; i<n; i++ ) { + writePixel(i, p); + p += 3; + } +} + +extern "C" void DMA0_IRQHandler() +{ + DMA_Type volatile *dma = DMA0; + TPM_Type volatile *tpm = TPM0; + + uint32_t db; + + db = dma->DMA[DMA_CHAN_0_LOW].DSR_BCR; + if (db & DMA_DSR_BCR_DONE_MASK) { + dma->DMA[DMA_CHAN_0_LOW].DSR_BCR = DMA_DSR_BCR_DONE_MASK; // clear/reset DMA status + } + + db = dma->DMA[DMA_CHAN_1_LOW].DSR_BCR; + if (db & DMA_DSR_BCR_DONE_MASK) { + dma->DMA[DMA_CHAN_1_LOW].DSR_BCR = DMA_DSR_BCR_DONE_MASK; // clear/reset DMA status + } + + db = dma->DMA[DMA_CHAN_START].DSR_BCR; + if (db & DMA_DSR_BCR_DONE_MASK) { + dma->DMA[DMA_CHAN_START].DSR_BCR = DMA_DSR_BCR_DONE_MASK; // clear/reset DMA status + } + + tpm->SC = TPM_SC_TOF_MASK; // reset TOF flag; disable internal clocking + + SET_DEBUG; + + // set TPM0 to interrrupt after guardtime + tpm->MOD = guardtime_period - 1; // 48MHz * 55 usec + tpm->CNT = 0; + tpm->SC = TPM_SC_PS(0) // 48MHz / 1 = 48MHz clock + | TPM_SC_TOIE_MASK // enable interrupts + | TPM_SC_CMOD(1); // and internal clocking +} + +extern "C" void TPM0_IRQHandler() +{ + TPM0->SC = 0; // disable internal clocking + TPM0->SC = TPM_SC_TOF_MASK; + RESET_DEBUG; + WS2811::dma_done = true; +}