Hi TI experts,
I've been experimenting with the USB driver code that is available through RTOS SDK of processors like am65, am57, etc.
I had some success enumerating a flash memory device that was communicating at high-speed. Unfortunately, the code fails during the enumeration process at setting the address step (address device step) when the device is a keyboard or dongle, which communicates at full speed. I'm wondering what causes this to happen. (my port is USB 2.0 capable only btw)
The specific file that this happens is : usb_xhci_hcd.c located in usb/src/xhci
the function that returns error code is : USB_HOST_xHCI_Address_Device
and this is a part of that function:
/*4.3.3 Device Slot Initialization */
memset(xhciContext, 0, sizeof(xhci_context_wrapper_t));
xhciContext->Input_Control_Context.add_flags |= 0x3 ; /* A0 and A1 set */
/*Set Context Entries to 1 */
xhciContext->Slot_Context.device_info0 |= (LAST_CTX(1)|
(0 << 26) | /* not a hub */
((Speed & 0xF) << 20)); /* Init speed and Port */
xhciContext->Slot_Context.device_info1 |= ROOT_HUB_PORT(xhciData->xhciPortNum) |
NUM_HUB_PORTS(0); /* no hub support yet... */
/* number of ports on hub goes here */
xhciContext->Slot_Context.ttinfo = 0; /* no hub support ... yet. */
xhciContext->Slot_Context.SlotState_Devadd = 0;
xhciContext->EndPoint_Context[0].epinfo1 |= (EP_TYPE(CTRL_EP)|
MAX_PACKET(xhciData->ep0MaxPs)|
MAX_BURST(0)|
ERROR_COUNT(3)); /* Error count 3 sec 4.8.2.1 in xHCI Spec */
xhciContext->EndPoint_Context[0].TRDeqPtrLo |= EP_CTX_CYCLE_MASK; /*DCS Set to 1 */
xhciContext->EndPoint_Context[0].TRDeqPtrLo |= (uint32_t) &xhciData->EP0_Transfer_Ring[0];
/*Form the Address device command Sec 6.4.3.4 in xHCI spec */
xhciData->Command_Ring[xhciData->byCommandRingIndex].command_trb_ptr_lo =
(uint32_t)&xhciContext->Input_Control_Context;
xhciData->Command_Ring[xhciData->byCommandRingIndex++].trb_slotid =
(TRB_TYPE(TRB_ADDRESS_DEVICE) |0x01 | SLOT_ID_FOR_TRB(xhciData->Slot_ID));
/* Command Ring */
HW_WR_REG32(baseAddr + DWC_USB_DB(1), DB_VALUE_HOST);
can you help me understand what is causing this failure? I highlighted a few parts that I thought maybe need to be modified in the full-speed mode.
Thanks,
please help me understand this part.
