/** \brief Processes the \ref GET_DESCRIPTOR request (returns the specified USB descriptor)
*
* The \ref module_usb_descriptor_parser module is used to locate device, configuration and string
* descriptors. Note that configuration descriptors also include interface, endpoint and other
* "similar" descriptor types (e.g. HID descriptor), with the total descriptor length specified by
* the \ref USB_CONFIGURATION_DESCRIPTOR.wTotalLength field.
*
* Other descriptor types that are not returned with the configuration descriptor, must be defined in
* the usbDescriptorMarker.pUsbDescLut lookup-table. This table specifies the values of the VALUE and INDEX fields, and
* gives a pointer to the descriptor along with it's length.
*
* <b>Parameters</b>:
* - VALUE.MSB: Descriptor type
* - VALUE.LSB: Descriptor index
* - INDEX: 0, or language ID for string descriptors (currently not supported)
* - LENGTH: Descriptor length (either the requested number of bytes, or the length of the descriptor,
* whichever is the smallest)
*
* <b>Data (IN)</b>:
* The descriptor(s)
*/
void usbsrGetDescriptor(void)
{
uint8 n;
// Which descriptor?
switch (HI_UINT16(usbSetupHeader.value)) {
// Device descriptor
case DESC_TYPE_DEVICE:
usbSetupData.pBuffer = (uint8 __code*) usbdpGetDeviceDesc();
usbSetupData.bytesLeft = usbSetupData.pBuffer[DESC_LENGTH_IDX];
break;
// Configuration descriptor
case DESC_TYPE_CONFIG:
usbSetupData.pBuffer = (uint8 __code*) usbdpGetConfigurationDesc(0, LO_UINT16(usbSetupHeader.value));
usbSetupData.bytesLeft = usbSetupData.pBuffer[DESC_CONFIG_LENGTH_LSB_IDX] +
usbSetupData.pBuffer[DESC_CONFIG_LENGTH_MSB_IDX] * 256;
break;
// String descriptor
case DESC_TYPE_STRING:
// OPT: Implement language ID
usbSetupData.pBuffer = (uint8 __code*) usbdpGetStringDesc(LO_UINT16(usbSetupHeader.value));
usbSetupData.bytesLeft = usbSetupData.pBuffer[DESC_LENGTH_IDX];
break;
// Other descriptor type
default:
// Perform a table search (on index and value)
usbSetupData.pBuffer = NULL;
for (n = 0; n < ((uint16)usbDescriptorMarker.pUsbDescLutEnd - (uint16)usbDescriptorMarker.pUsbDescLut) / sizeof(DESC_LUT_INFO); n++) {
if ((usbDescriptorMarker.pUsbDescLut[n].valueMsb == HI_UINT16(usbSetupHeader.value))
&& (usbDescriptorMarker.pUsbDescLut[n].valueLsb == LO_UINT16(usbSetupHeader.value))
&& (usbDescriptorMarker.pUsbDescLut[n].indexMsb == HI_UINT16(usbSetupHeader.index))
&& (usbDescriptorMarker.pUsbDescLut[n].indexLsb == LO_UINT16(usbSetupHeader.index)) )
{
usbSetupData.pBuffer = usbDescriptorMarker.pUsbDescLut[n].pDescStart;
usbSetupData.bytesLeft = usbDescriptorMarker.pUsbDescLut[n].length;
}
}
}
// Stall EP0 if no descriptor was found
if (usbSetupData.pBuffer == NULL) usbfwData.ep0Status = EP_STALL;
if (usbfwData.ep0Status != EP_STALL) {
// Limit the returned descriptor size (the PC wants to know about sizes before
// polling the complete descriptors)
if (usbSetupData.bytesLeft > usbSetupHeader.length) {
usbSetupData.bytesLeft = usbSetupHeader.length;
}
usbfwData.ep0Status = EP_TX;
}
} // usbsrGetDescriptor
/** \brief Initializes the USB framework
*
* This function should be called when the microcontroller is ready to accept USB traffic. It enables the
* USB peripheral unit and enables the pull-up resistor on the D+ line. Endpoint status, current
* configuration value, etc. are initialized and evenetually re-initialized in the
* \ref usbfwResetHandler() function.
*/
void usbfwInit(void)
{
// Set default values
usbfwData.selfPowered = (usbdpGetConfigurationDesc(1, 0)->bmAttributes & 0x40) ? TRUE : FALSE;
usbfwData.remoteWakeup = FALSE;
HAL_USB_ENABLE();
// Enable Resume Interrupt
HAL_USB_RESUME_INT_ENABLE();
} // usbfwInit
/** \brief Locates an interface descriptor
*
* The function will first go to the configuration descriptor that matches the supplied configuration
* value, and then locate the interface descriptor that matches the given interface number and alternate
* setting.
*
* \note It is not necessary to call \ref usbdpInit() before this function.
*
* \param[in] cfgValue
* The configuration value (\ref USB_CONFIGURATION_DESCRIPTOR.bConfigurationValue)
* \param[in] intNumber
* The interface number (\ref USB_INTERFACE_DESCRIPTOR.bInterfaceNumber)
* \param[in] altSetting
* The alternate setting (\ref USB_INTERFACE_DESCRIPTOR.bAlternateSetting)
*
* \return
* A pointer to the \ref USB_INTERFACE_DESCRIPTOR, or \c NULL if it was not found.
*/
USB_INTERFACE_DESCRIPTOR __code* usbdpGetInterfaceDesc(uint8 cfgValue, uint8 intNumber, uint8 altSetting)
{
USB_INTERFACE_DESCRIPTOR __code *pInterfaceDesc;
// First get to the correct configuration
usbdpGetConfigurationDesc(cfgValue, 0);
// Then find a match on the interface
while (pInterfaceDesc = usbdpFindNext(DESC_TYPE_INTERFACE, DESC_TYPE_CONFIG)) {
if ((pInterfaceDesc->bInterfaceNumber == intNumber) && (pInterfaceDesc->bAlternateSetting == altSetting)) {
break;
}
}
return pInterfaceDesc;
} // usbdpGetInterfaceDesc
/** \brief Initializes the USB framework
*
* This function should be called when the microcontroller is ready to accept USB traffic. It enables the
* USB peripheral unit and enables the pull-up resistor on the D+ line.
*/
void usbfwInit(void)
{
//
// Set default values
//
usbfwData.selfPowered = (usbdpGetConfigurationDesc(1, 0)->bmAttributes & 0x40) ? true : false;
usbfwData.remoteWakeup = false;
usbfwResetHandler();
//
// Enable the USB peripheral unit
//
UsbEnable();
//
// Allow the USB pad IP to to enter standby
//
HWREG(CCTEST_USBCTRL) = CCTEST_USBCTRL_USB_STB_M;
}
/** \brief Processes the \c GET_DESCRIPTOR request (returns the specified USB descriptor)
*
* The descriptors are retrieved using either the \ref module_usb_descriptor_parser module's automatic
* parsing functions (for device and configuration descriptors), or the manually generated
* \ref pUsbDescriptorLut[] lookup table (for string and non-standard formatted descriptors). When the
* USB host requests the configuration descriptor, this includes also the interface descriptors and their
* sub-descriptors, with a total length specified by \ref USB_CONFIGURATION_DESCRIPTOR.wTotalLength.
*
* The \ref pUsbDescriptorLut[] lookup table takes the expected VALUE and INDEX fields for each
* descriptor, and returns pointer and length.
*
* <b>Parameters</b>:
* - VALUE.MSB: Descriptor type
* - VALUE.LSB: Descriptor index
* - INDEX: 0, or language ID for string descriptors (currently not supported)
* - LENGTH: Descriptor length (either the requested number of bytes, or the length of the descriptor,
* whichever is the smallest)
*
* <b>Data (IN)</b>:
* The descriptor(s)
*/
void usbsrGetDescriptor(void)
{
const USB_DESCRIPTOR_LUT* pUsbDescriptorLutEntry;
//
// Which descriptor?
//
switch(usbSetupHeader.valueMsb)
{
case USB_DESC_TYPE_DEVICE:
//
// Device descriptor
//
usbSetupData.pBuffer = (void*) usbdpGetDeviceDesc();
usbSetupData.bytesLeft = ((USB_DEVICE_DESCRIPTOR*) usbSetupData.pBuffer)->bLength;
break;
case USB_DESC_TYPE_CONFIG:
//
// Configuration descriptor
//
usbSetupData.pBuffer = (void*) usbdpGetConfigurationDesc(0, usbSetupHeader.valueLsb);
usbSetupData.bytesLeft = ((USB_CONFIGURATION_DESCRIPTOR*) usbSetupData.pBuffer)->wTotalLength;
break;
default:
//
// String or other type descriptor
//
pUsbDescriptorLutEntry = usbdpGetDescByLut(usbSetupHeader.value, usbSetupHeader.index);
if(pUsbDescriptorLutEntry)
{
usbSetupData.pBuffer = (void*) pUsbDescriptorLutEntry->pDesc;
usbSetupData.bytesLeft = pUsbDescriptorLutEntry->length;
}
else
{
//
// Not found, so stall below
//
usbSetupData.pBuffer = NULL;
}
}
//
// Stall EP0 if no descriptor was found
//
if(!usbSetupData.pBuffer)
{
usbfwData.ep0Status = EP_STALL;
}
if(usbfwData.ep0Status != EP_STALL)
{
//
// Limit the returned descriptor size (the PC wants to know about sizes before
// polling the complete descriptors)
//
if(usbSetupData.bytesLeft > usbSetupHeader.length)
{
usbSetupData.bytesLeft = usbSetupHeader.length;
}
usbfwData.ep0Status = EP_TX;
}
}
