//*****************************************************************************
//
// Given a maximum packet size and the user's FIFO scaling requirements,
// determine the flags to use to configure the endpoint FIFO and the number
// of bytes of FIFO space occupied.
//
//*****************************************************************************
static uint32_t
GetEndpointFIFOSize(uint32_t ui32MaxPktSize, uint32_t *pupBytesUsed)
{
uint32_t ui32Loop, ui32FIFOSize;
//
// Now we need to find the nearest supported size that accommodates the
// requested size. Step through each of the supported sizes until we
// find one that will do.
//
for(ui32Loop = USB_FIFO_SZ_8; ui32Loop <= USB_FIFO_SZ_2048; ui32Loop++)
{
//
// How many bytes does this FIFO value represent?
//
ui32FIFOSize = USBFIFOSizeToBytes(ui32Loop);
//
// Is this large enough to hold one packet.
//
if(ui32FIFOSize >= ui32MaxPktSize)
{
//
// Return the FIFO size setting and the USB_FIFO_SZ_ value.
//
*pupBytesUsed = ui32FIFOSize;
return(ui32Loop);
}
}
//
// If we drop out, we can't support the FIFO size requested. Signal a
// problem by returning 0 in the pBytesUsed
//
*pupBytesUsed = 0;
return(USB_FIFO_SZ_8);
}
USB_HID_SCLASS_BOOT, // The interface sub-class.
USB_HID_PROTOCOL_KEYB, // The interface protocol for the sub-class
// specified above.
4, // The string index for this interface.
};
static const uint8_t g_pui8HIDInEndpoint[HIDINENDPOINT_SIZE] =
{
//
// Interrupt IN endpoint descriptor
//
7, // The size of the endpoint descriptor.
USB_DTYPE_ENDPOINT, // Descriptor type is an endpoint.
USB_EP_DESC_IN | USBEPToIndex(USB_EP_1),
USB_EP_ATTR_INT, // Endpoint is an interrupt endpoint.
USBShort(USBFIFOSizeToBytes(USB_FIFO_SZ_64)),
// The maximum packet size.
16, // The polling interval for this endpoint.
};
static const uint8_t g_pui8HIDOutEndpoint[HIDOUTENDPOINT_SIZE] =
{
//
// Interrupt OUT endpoint descriptor
//
7, // The size of the endpoint descriptor.
USB_DTYPE_ENDPOINT, // Descriptor type is an endpoint.
USB_EP_DESC_OUT | USBEPToIndex(USB_EP_2),
USB_EP_ATTR_INT, // Endpoint is an interrupt endpoint.
USBShort(USBFIFOSizeToBytes(USB_FIFO_SZ_64)),
// The maximum packet size.