Serial_::operator bool()
{
bool result = false;
if(USBDevice.configured()
&& (_cdcLineState & CONTROL_LINE_STATE_DTR)
&& !USB_IsSendQFull(CDC_TX)
// && !USB_IsStalled(CDC_TX)
)
{
result = true;
}
// We add a short delay before returning to fix a bug observed by Federico
// where the port is configured (_cdcLineState != 0) but not quite opened.
// delay(10);
if(!result)
{
if(!USBDevice.configured())
{
#ifdef DEBUG_CODE
error_printP(F("USB device not configured"));
#endif // DEBUG_CODE
}
else if(!(_cdcLineState & CONTROL_LINE_STATE_DTR))
{
#ifdef DEBUG_CODE
error_printP(F("DTR is off"));
#endif // DEBUG_CODE
}
else if(USB_IsSendQFull(CDC_TX))
{
#ifdef DEBUG_CODE
error_printP(F("Send Queue FULL"));
#endif // DEBUG_CODE
}
// else if(USB_IsStalled(CDC_TX))
// {
//#ifdef DEBUG_CODE
// error_printP(F("USB is stalled"));
//#endif // DEBUG_CODE
// }
}
return result;
}
bool WEAK CDC_Setup(Setup& setup)
{
u8 r = setup.bRequest;
u8 requestType = setup.bmRequestType;
if(REQUEST_DEVICETOHOST_CLASS_INTERFACE == requestType)
{
if (CDC_GET_LINE_CODING == r)
{
error_printP(F("Get Line Coding"));
#if 1
USB_SendControl(0,(void*)&_usbLineInfo, sizeof(_usbLineInfo)/*7*/);
#endif // 0
return true;
}
}
else if(REQUEST_HOSTTODEVICE_CLASS_INTERFACE == requestType)
{
if(CDC_SET_LINE_CODING == r)
{
error_printP_(F("CDC_SET_LINE_CODING"));
// setup packet is followed by data?
memcpy((void *)&_usbLineInfo, (char *)&(setup) + sizeof(Setup), sizeof(_usbLineInfo));
error_printP_(F(" rate:"));
error_printL_(_usbLineInfo.dwDTERate);
error_printP_(F(" fmt:"));
error_printL_(_usbLineInfo.bCharFormat);
error_printP_(F(" par:"));
error_printL_(_usbLineInfo.bParityType);
error_printP_(F(" bit:"));
error_printL(_usbLineInfo.bDataBits);
USB_SendControl(0, NULL, 0); // send a ZLP
_cdcLineState = CONTROL_LINE_STATE_DTR; // for now... assume "this"
// now set up the ACM interrupt info in '_cdcSerialState' and send it back
_cdcSerialState = SERIAL_STATE_TX_CARRIER_DSR; // to tell host "I have data" (always)
return true;
}
else if(CDC_SET_CONTROL_LINE_STATE == r)
{
error_printP_(F("Set Control Line State: "));
error_printL(setup.wValueL);
_cdcLineState = setup.wValueL;
// NOTE: this next part is for the 'caterina' CDC bootloader, arduino/bootloaders/caterina/Caterina.c
// it has some "special" code in it, like using 0x0800 in RAM as an address for a 'key' (7777H)
// to indicate it was soft-booted. XMEGA has better ways of handling this, like a CPU flag that
// indicates "I was soft-booted" as one example, and a 'WDT' timeout flag on top of that.
// auto-reset into the bootloader is triggered when the port, already
// open at 1200 bps, is closed. this is the signal to start the watchdog
// with a relatively long period so it can finish housekeeping tasks
// like servicing endpoints before the sketch ends
if (1200 == _usbLineInfo.dwDTERate)
{
// We check DTR state to determine if host port is open (bit 0 of _cdcLineState).
if ((_cdcLineState & 0x01) == 0)
{
// This section of code is support for the 'caterina' bootloader, which allows USB flashing (apparently)
//
// *(uint16_t *)0x0800 = 0x7777; note that on XMEGA this is a VERY bad thing
// wdt_enable(WDTO_120MS);
//
// on the atmega, address 800H is the start of the final 256-byte page in RAM space for 2k RAM
//
// atmega328(p) RAM goes from 0x100 through 0x8ff - see datasheet for atmega 328 [etc.] section 8.3
// 32U4 RAM goes through 0xaff - see datasheet for U4 processors, section 5.2
// 8/16/32U2 RAM goes through 4FFH so this won't even work - see datasheet for U2 processors, section 7.2
// basically it's a 'hack' and needs to be re-evaluated
// TODO: would it be safe to enable interrupts, NOT return from this function,
// and simply wait until the appropriate time has elapsed? Or, as is
// handled in the section below, this 'wait period' is canceled
// TODO: if I use a function that's part of the USB driver to trigger a soft boot, I can detect
// that a soft boot has taken place using the bits in the 'RESET' status register. If all
// I have to do is detect this, it's not a problem, and I won't need "magic memory locations"
// TODO: timeout-based reboot
}
else
{
// Most OSs do some intermediate steps when configuring ports and DTR can
// twiggle more than once before stabilizing.
// To avoid spurious resets we set the watchdog to 250ms and eventually
// cancel if DTR goes back high.
// This section of code is support for the 'caterina' bootloader, which allows USB flashing (apparently)
//
// TODO: reset whatever boot timeout I did
// wdt_disable();
// wdt_reset();
// *(uint16_t *)0x0800 = 0x0; note that on XMEGA this is a VERY bad thing
}
}
USB_SendControl(0, NULL, 0); // send a ZLP
return true;
}
}
// unrecognized request - report it
error_printP_(F("CDC request: type="));
error_printL_(requestType);
error_printP_(F(" request="));
error_printL(r);
return false;
}
