DMAChannel help for reading camera data bus

// Pins
const byte VSYNC = 9;
const byte HREF = 10;
const byte PCLK = 11;

static const uint16_t bufferSize = 100000;
uint16_t imageBytes = 0;
uint8_t image[bufferSize]; // max space, should be enough since data is jpg compressed.


inline bool checkVSync(void) {
	return digitalReadFast(VSYNC);
}

inline bool checkHRef(void) {
	return digitalReadFast(HREF);
}

inline bool checkPClk(void) {
	return digitalReadFast(PCLK);
}

void acquireJPGImage(void) {
	imageBytes = 0;
	uint8_t imageByte;
	while (checkVSync());    // Wait for the old frame to end
	while (!checkVSync());  // Wait for a new frame to start

	while (checkVSync()) {
		while (checkVSync() && !checkHRef()); // Wait for a line to start
		if (!checkVSync()) {
			break;  // Line didn't start, but frame ended
		}
		while (!checkPClk()); // Wait for clock to go high
		imageByte = GPIOD_PDIR & 0xFF; // read the data
		if (imageBytes < bufferSize)
			image[imageBytes++] = imageByte;
		while (checkPClk());   // Wait for clock to go back low
	}
}

DMAChannel dma;       // dma Channel

void dmaInit(void) {
	// const byte PCLK = 11; native C6
	// Configure to trigger DMA of falling edge of signal applied to Pin 6
	SIM_SCGC5 |= SIM_SCGC5_PORTC;
	CORE_PIN2_CONFIG = PORT_PCR_MUX(1) | PORT_PCR_IRQC(6);
	SIM_SCGC6 |= SIM_SCGC6_DMAMUX;
	SIM_SCGC7 |= SIM_SCGC7_DMA;


	dma.source(*(uint8_t*)&GPIOD_PDIR);
	dma.destinationBuffer(image, sizeof(image));
	// An interrupt routine can be run when the DMA channel completes
	// the entire transfer, and also optionally when half of the
	// transfer is completed.
	dma.attachInterrupt(dma_isr); 
	dma.interruptAtCompletion();
	// Triggers cause the DMA channel to actually move data.  Each
	// trigger moves a single data unit, which is typically 8, 16 or
	// 32 bits.  If a channel is configured for 200 transfers
	// Use a hardware trigger to make the DMA channel run
	// const byte PCLK = 11; native C6
	dma.triggerAtHardwareEvent(DMAMUX_SOURCE_PORTD);
	dma.enable();
}

void dma_isr() {
	dma.detachInterrupt();
	dma.disable();
}