WinCE

On resuming from sleep mode of PXA27X, the usb client wont be working straight away. No insertion events will be detected and the device will be shown as an uknown device in PC.

For overcoming this situation, we have to clear the OTGPH bit in PSSR (Power Manager Sleep Status Register). This is a write to clear bit.

OTGPH will be set when entering sleep mode when writing the PWRMODE register and indicates that the OTG pad is retaining state. So after resuming, the USB OTG, UDC and UHC should be configured, then only clear the OTGPH bit.

Referece : Marvell PXA27X Processor Developer Manual, November 3 , 2006

Hi guys,

Here is a code for changing the current usb client function from Serial to Mass storage dynamically.

/*
* #FUNCTION
*
* @Function: GetUfnController
* @Return: INVALID_HANDLE_VALUE - USB Function device was not found
*   Otherwise, if found
* @Parameters: 
* @Description:
*  Function to get the handle of a USB Client device.
*/
HANDLE GetUfnController()
{
HANDLE hUfn = NULL;
// Get a handle to the bus driver
DEVMGR_DEVICE_INFORMATION di;
memset(&di, 0, sizeof(di));
di.dwSize = sizeof(di);

#ifdef _SEARCH_WITH_GUID_
BYTE rgbGuidBuffer[sizeof(GUID) + 4]; // +4 because scanf writes longs
memset(&rgbGuidBuffer[0],0,sizeof(GUID) + 4);
LPGUID pguidBus = (LPGUID) rgbGuidBuffer;
LPCTSTR pszBusGuid = _T("E2BDC372-598F-4619-BC50-54B3F7848D35");
// Parse the GUID
if (FALSE == ConvertStringToGuid(&pszBusGuid[0],pguidBus) )
return INVALID_HANDLE_VALUE;
HANDLE hf = FindFirstDevice(DeviceSearchByGuid, pguidBus, &di);
#else
HANDLE hf = FindFirstDevice(DeviceSearchByLegacyName, L"UFN1:", &di);
#endif /* _SEARCH_WITH_GUID_ */
if (hf != INVALID_HANDLE_VALUE) {
hUfn = CreateFile(di.szBusName, GENERIC_READ, FILE_SHARE_READ,NULL, OPEN_EXISTING, 0, NULL);
CloseHandle(hf);
}
else {
hUfn = INVALID_HANDLE_VALUE;
}
return hUfn;
} /* GetUfnController */

/*
* #FUNCTION
*
* @Function: ChangeClient
* @Return: TRUE - Client Function change was succesful
*   FALSE - Client Function change failed
* @Parameters:
*   hUfn - Handle to the USB client device
*   pszNewClient - New usb function to be loaded
* @Description:
*  Function to switch the active usb client function driver
*/
BOOL ChangeClient(HANDLE hUfn, LPCTSTR pszNewClient)
{
if(hUfn == INVALID_HANDLE_VALUE || pszNewClient == NULL)
return ERROR_INVALID_PARAMETER;
DWORD dwRet = ERROR_SUCCESS;
UFN_CLIENT_NAME ucn;
_tcscpy(ucn.szName, pszNewClient);
BOOL fSuccess = DeviceIoControl(hUfn,
IOCTL_UFN_CHANGE_CURRENT_CLIENT, &ucn, sizeof(ucn), NULL, 0, NULL, NULL);
return fSuccess;
} /* ChangeClient */