// usb host experiments....

void setup()
{
	pinMode(32, OUTPUT);	// pin 32 = USB switch, high=connect device
	digitalWrite(32, LOW);
	while (!Serial) ; // wait
	print("USB Host Testing");
	MCG_C1 |= MCG_C1_IRCLKEN;  // enable MCGIRCLK 32kHz
	OSC0_CR |= OSC_ERCLKEN;
	SIM_SOPT2 |= SIM_SOPT2_USBREGEN; // turn on USB regulator
	SIM_SOPT2 &= ~SIM_SOPT2_USBSLSRC; // use IRC for slow clock
	print("power up USBHS PHY");
	SIM_USBPHYCTL |= SIM_USBPHYCTL_USBDISILIM; // disable USB current limit
	SIM_USBPHYCTL = SIM_USBPHYCTL_USBDISILIM | SIM_USBPHYCTL_USB3VOUTTRG(6); // pg 237
	SIM_SCGC3 |= SIM_SCGC3_USBHSDCD | SIM_SCGC3_USBHSPHY | SIM_SCGC3_USBHS;
	print("init USBHS PHY & PLL");
	// init process: page 1681-1682
	USBPHY_CTRL &= ~USBPHY_CTRL_SFTRST;	// CTRL pg 1698
	USBPHY_CTRL &= ~USBPHY_CTRL_CLKGATE;
	USBPHY_PLL_SIC |= USBPHY_PLL_SIC_PLL_POWER;
	USBPHY_PLL_SIC |= USBPHY_PLL_SIC_PLL_DIV_SEL(1);  // PLL_SIC pg 1708
	// wait for the PLL to lock
	int count=0;
	while ((USBPHY_PLL_SIC & USBPHY_PLL_SIC_PLL_LOCK) == 0) {
		count++;
	}
	print("PLL locked, waited ", count);
	USBPHY_PLL_SIC |= USBPHY_PLL_SIC_PLL_EN_USB_CLKS;
	USBPHY_PWD = 0;
	delay(10);

	// sanity check, connect 470K pullup & 100K pulldown and watch D+ voltage change
	//USBPHY_ANACTRL_CLR = (1<<10); // turn off both 15K pulldowns... works! :)

	// sanity check, output clocks on pin 9 for testing
	//SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(3); // LPO 1kHz
	//SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(2); // Flash
	//SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(6); // XTAL
	//SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(7); // IRC 48MHz
	//SIM_SOPT2 = SIM_SOPT2 & (~SIM_SOPT2_CLKOUTSEL(7)) | SIM_SOPT2_CLKOUTSEL(4); // MCGIRCLK
	//CORE_PIN9_CONFIG = PORT_PCR_MUX(5);  // CLKOUT on PTC3 Alt5 (Arduino pin 9)

// EHCI registers         page  default
// --------------         ----  -------
// USBHS_USBCMD           1599  00080000
// USBHS_USBSTS           1602  00000000
// USBHS_USBINTR          1606  00000000
// USBHS_FRINDEX          1609  00000000
// USBHS_PERIODICLISTBASE 1610  undefine
// USBHS_ASYNCLISTADDR    1612  undefine
// USBHS_PORTSC           1619  00002000
// USBHS_USBMODE          1629  00005000

	USBHS_USBINTR = 0;
	USBHS_PERIODICLISTBASE = 0; // TODO: data..
	USBHS_ASYNCLISTADDR = 0;    // TODO: data..

	// turn on the USBHS controller
	USBHS_USBMODE = USBHS_USBMODE_TXHSD(5) | USBHS_USBMODE_CM(3); // host mode
	USBHS_USBCMD = USBHS_USBCMD_ITC(8) | USBHS_USBCMD_RS |
		USBHS_USBCMD_FS2 | USBHS_USBCMD_FS(0); // periodic table is 64 pointers
	USBHS_PORTSC1 |= USBHS_PORTSC_PP;
}

void port_status()
{
	uint32_t n;

	Serial.print("Port: ");
	n = USBHS_PORTSC1;
	if (n & USBHS_PORTSC_PR) {
		Serial.print("reset ");
	}
	if (n & USBHS_PORTSC_PP) {
		Serial.print("on ");
	} else {
		Serial.print("off ");
	}

	if (n & USBHS_PORTSC_PE) {
		if (USBHS_PORTSC_SUSP) {
			Serial.print("suspend ");
		} else {
			Serial.print("enable ");   // not working... why?
		}
	} else {
		Serial.print("disable ");
	}
	Serial.print("speed=");
	switch ((n >> 26) & 3) {
	  case 0: Serial.print("12 Mbps "); break;
	  case 1: Serial.print("1.5 Mbps "); break;
	  case 2: Serial.print("480 Mbps "); break;
	  default: Serial.print("(undef) ");
	}
	if (n & USBHS_PORTSC_HSP) {
		Serial.print("highspeed ");
	}
	if (n & USBHS_PORTSC_OCA) {
		Serial.print("overcurrent ");
	}
	if (n & USBHS_PORTSC_CCS) {
		Serial.print("connected");
	} else {
		Serial.print("not-connected");
	}
	Serial.println();
}


void loop()
{
	static unsigned int count=0;

	port_status();
	delay(1);
	count++;
	if (count == 2) {
		Serial.println("Plug in device...");
		digitalWrite(32, HIGH); // connect device
	}
	if (count == 6) {
		Serial.println("Initiate Reset Sequence...");
		USBHS_PORTSC1 |= USBHS_PORTSC_PR;
	}
	if (count == 16) {
		Serial.println("End Reset Sequence...");
		USBHS_PORTSC1 &= ~USBHS_PORTSC_PR;
	}

}

void print(const char *s)
{
	Serial.println(s);
	delay(10);
}

void print(const char *s, int num)
{
	Serial.print(s);
	Serial.println(num);
	delay(10);
}