WS2812Serial/WS2812Serial.cpp

/*  WS2812Serial - Non-blocking WS2812 LED Display Library
    https://github.com/PaulStoffregen/WS2812Serial
    Copyright (c) 2017 Paul Stoffregen, PJRC.COM, LLC

    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 "WS2812Serial.h"

bool WS2812Serial::begin()
{
	uint32_t divisor, portconfig, hwtrigger;
	KINETISK_UART_t *uart;

	switch (pin) {
#if defined(KINETISK) // Teensy 3.x
	  case 1: // Serial1
	  case 5:
	#if defined(__MK64FX512__) || defined(__MK66FX1M0__)
	  case 26:
	#endif
		uart = &KINETISK_UART0;
		divisor = BAUD2DIV(4000000);
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART0_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART0;
		break;

	  case 10: // Serial2
	#if defined(__MK20DX128__) || defined(__MK20DX256__)
	  case 31:
	#elif defined(__MK64FX512__) || defined(__MK66FX1M0__)
	  case 58:
	#endif
		uart = &KINETISK_UART1;
		divisor = BAUD2DIV2(4000000);
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART1_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART1;
		break;

	  case 8: // Serial3
	  case 20:
		uart = &KINETISK_UART2;
		divisor = BAUD2DIV3(4000000);
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART2_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART2;
		break;

	#if defined(__MK64FX512__) || defined(__MK66FX1M0__)
	  case 32: // Serial4
	  case 62:
		uart = &KINETISK_UART3;
		divisor = BAUD2DIV3(4000000);
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART3_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART3;
		break;

	  case 33: // Serial5
		uart = &KINETISK_UART4;
		divisor = BAUD2DIV3(4000000);
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART4_RXTX;
		SIM_SCGC1 |= SIM_SCGC1_UART4;
		break;
	#endif
	#if defined(__MK64FX512__)
	  case 48: // Serial6
		uart = &KINETISK_UART5;
		divisor = BAUD2DIV3(4000000);
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART5_RXTX;
		SIM_SCGC1 |= SIM_SCGC1_UART5;
		break;
	#endif

#elif defined(KINETISL)	// Teensy LC
	  case 1: // Serial1
	  case 5:
		uart = &KINETISK_UART0;
		divisor = 1;
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(3);
		hwtrigger = DMAMUX_SOURCE_UART0_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART0;
		break;
	  case 4:
		uart = &KINETISK_UART0;
		divisor = 1;
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(2);
		hwtrigger = DMAMUX_SOURCE_UART0_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART0;
		break;
	  case 24:
		uart = &KINETISK_UART0;
		divisor = 1;
		portconfig = PORT_PCR_DSE | PORT_PCR_SRE | PORT_PCR_MUX(4);
		hwtrigger = DMAMUX_SOURCE_UART0_TX;
		SIM_SCGC4 |= SIM_SCGC4_UART0;
		break;
#endif
	  default:
		return false; // pin not supported
	}
	if (!dma) {
		dma = new DMAChannel;
		if (!dma) return false; // unable to allocate DMA channel
	}
#if defined(KINETISK)
	if (divisor < 32) divisor = 32;
	uart->BDH = (divisor >> 13) & 0x1F;
	uart->BDL = (divisor >> 5) & 0xFF;
	uart->C4 = divisor & 0x1F;
#elif defined(KINETISL)
	uart->BDH = (divisor >> 8) & 0x1F;
	uart->BDL = divisor & 0xFF;
	uart->C4 = 11;
#endif
	uart->C1 = 0;
	uart->C2 = UART_C2_TE | UART_C2_TIE;
	uart->C3 = UART_C3_TXINV;
	uart->C5 = UART_C5_TDMAS;
#if defined(KINETISK)
	uart->PFIFO = 0; // TODO: is this ok for Serial3-6?
#endif
	*(portConfigRegister(pin)) = portconfig;
	dma->destination(uart->D);
	dma->triggerAtHardwareEvent(hwtrigger);
	memset(drawBuffer, 0, numled * 3);
	return true;
}

void WS2812Serial::show()
{
	// wait if prior DMA still in progress
#if defined(KINETISK)
	while ((DMA_ERQ & (1 << dma->channel))) {
		yield();
	}
#elif defined(KINETISL)
	while ((dma->CFG->DCR & DMA_DCR_ERQ)) {
		yield();
	}
#endif
	// copy drawing buffer to frame buffer
	const uint8_t *p = drawBuffer;
	const uint8_t *end = p + (numled * 3);
	uint8_t *fb = frameBuffer;
	while (p < end) {
		uint8_t b = *p++;
		uint8_t g = *p++;
		uint8_t r = *p++;
		uint32_t n=0;
		switch (config) {
		  case WS2812_RGB: n = (r << 16) | (g << 8) | b; break;
		  case WS2812_RBG: n = (r << 16) | (b << 8) | g; break;
		  case WS2812_GRB: n = (g << 16) | (r << 8) | b; break;
		  case WS2812_GBR: n = (g << 16) | (b << 8) | r; break;
		  case WS2812_BRG: n = (b << 16) | (r << 8) | g; break;
		  case WS2812_BGR: n = (b << 16) | (g << 8) | r; break;
		}
		const uint8_t *stop = fb + 12;
		do {
			uint8_t x = 0x08;
			if (!(n & 0x00800000)) x |= 0x07;
			if (!(n & 0x00400000)) x |= 0xE0;
			n <<= 2;
			*fb++ = x;
		} while (fb < stop);
	}
	// wait 300us WS2812 reset time
	uint32_t min_elapsed = (numled * 30) + 300;
	if (min_elapsed < 2500) min_elapsed = 2500;
	uint32_t m;
	while (1) {
		m = micros();
		if ((m - prior_micros) > min_elapsed) break;
		yield();
	}
	prior_micros = m;
	// start DMA transfer to update LEDs  :-)
#if defined(KINETISK)
	dma->sourceBuffer(frameBuffer, numled * 12);
	dma->transferSize(1);
	dma->transferCount(numled * 12);
	dma->disableOnCompletion();
	dma->enable();
#elif defined(KINETISL)
	dma->CFG->SAR = frameBuffer;
	dma->CFG->DSR_BCR = 0x01000000;
	dma->CFG->DSR_BCR = numled * 12;
	dma->CFG->DCR = DMA_DCR_ERQ | DMA_DCR_CS | DMA_DCR_SSIZE(1) |
		DMA_DCR_SINC | DMA_DCR_DSIZE(1) | DMA_DCR_D_REQ;
#endif
}