I need to set the MS OS String Descriptor (index = 0xEE)

This is necessary for WinUSB class driver support on Windows 8.

But a call to CyU3PUsbSetDesc(CY_U3P_USB_SET_STRING_DESCR, 0xEE,...)

just fails, returning Error code = 75

I assume this is because the descriptors are hardwired to IDs 0 to 15?

Can we get a fix for this?

Am I going to have similar trouble with OS Feature descriptors?

Thanks

Yep. You're right.

The error code being returned is CY_U3P_ERROR_BAD_INDEX and is being triggered due to CY_U3P_MAX_STRING_DESC_INDEX in cyu3usb.h. You can see the required description above the #define.

I'll talk our software team and let you know.

Regards,

Anand

Hi,

You are right that the FX3 SDK does not let you set a OS descriptor using the CyU3PUsbSetDesc() API.

However, this does not prevent you from supporting a OS descriptor in your application. You can support do this at the application level by handling the request in your setup callback function. See the below code snippet:

/* Microsoft OS Descriptor. */ const uint8_t CyFxUsbOSDscr[] __attribute__ ((aligned (32))) = {     0x0E, CY_U3P_USB_STRING_DESCR,     'O', 0x00, 'S', 0x00,     ' ', 0x00, 'D', 0x00,     'e', 0x00, 's', 0x00,     'c', 0x00 };  /* Callback to handle the USB setup requests. */ CyBool_t CyFxBulkSrcSinkApplnUSBSetupCB (         uint32_t setupdat0, /* SETUP Data 0 */         uint32_t setupdat1  /* SETUP Data 1 */     ) {     /* Fast enumeration is used. Only requests addressed to the interface, class,      * vendor and unknown control requests are received by this function.      * This application does not support any class or vendor requests. */      uint8_t  bRequest, bReqType;     uint8_t  bType, bTarget;     uint16_t wValue, wIndex, wLength;     CyBool_t isHandled = CyFalse;      /* Decode the fields from the setup request. */     bReqType = (setupdat0 & CY_U3P_USB_REQUEST_TYPE_MASK);     bType    = (bReqType & CY_U3P_USB_TYPE_MASK);     bTarget  = (bReqType & CY_U3P_USB_TARGET_MASK);     bRequest = ((setupdat0 & CY_U3P_USB_REQUEST_MASK) >> CY_U3P_USB_REQUEST_POS);     wValue   = ((setupdat0 & CY_U3P_USB_VALUE_MASK)   >> CY_U3P_USB_VALUE_POS);     wIndex   = ((setupdat1 & CY_U3P_USB_INDEX_MASK)   >> CY_U3P_USB_INDEX_POS);     wLength  = ((setupdat1 & CY_U3P_USB_LENGTH_MASK)  >> CY_U3P_USB_LENGTH_POS);      if (bType == CY_U3P_USB_STANDARD_RQT)     {         /* Handle Microsoft OS String Descriptor request. */         if ((bTarget == CY_U3P_USB_TARGET_DEVICE) && (bRequest == CY_U3P_USB_SC_GET_DESCRIPTOR) &&                 (wValue == ((CY_U3P_USB_STRING_DESCR << 8) | 0xEE)))         {             /* Make sure we do not send more data than requested. */             if (wLength > CyFxUsbOSDscr[0])                 wLength = CyFxUsbOSDscr[0];              CyU3PUsbSendEP0Data (wLength, (uint8_t *)CyFxUsbOSDscr);             isHandled = CyTrue;         }          /* Handle other requests below as required. */     }      return isHandled; }   For now, please use the above work-around. API level support for registering a OS descriptor
will be added in a later FX3 SDK release.

The code formatting in the last post does not look good. I am attaching the complete example source code.

Regards,

Karthik

Thanks guys.

I'm travelling now so although I can build OK I can't deploy it right now.

I've picked it up and will give it a shot when I am back in my office next week.

And if I run into any trouble with the other MS specific feature descriptors I'll report back here.

I thought I should report back.

I did run into a bit more trouble trying to make a WinUSB class device for Windows 8.

The OS feature Descriptor is fetched as Vendor specific request.   ie   bType == CY_U3P_USB_VENDOR_RQT
but it is still a string descriptor.   ie  bRequest == CY_U3P_USB_SC_GET_DESCRIPTOR and wValue == 0x03EE
I modified the example code for  CyFxBulkSrcSinkApplnUSBSetupCB()  accordingly.

Same goes for the Extended Compat ID OS Feature Descriptor.
That also gets fetched as a Vendor type, with the user-specified (in the OS descriptor) value in bRequest.

I think you have to do all this if you want to use WinUSB on Windows 8 because if I try to load my Windows 8 signed inf+cat specifying winusb (as I do on Windows 7 x64) I get an error message from Windows-8 saying "Windows found driver software for your device but encountered an error whil attempting to install it". Unliek Win7 it also would nto even look at my inf file unless I also gave it a matching signed cat file.

Can anyone here using WinUSB confirm this? Do Win7 style WinUSB inf installs relly not work on Win8?

Thanks

Hi aasi

also, I cannot build the example code you posted. It looks like it may be for a SDK newer than the one I have.

I have the v1.1 SDK from http://www.cypress.com/?rID=57990

Where can I get a newer SDK?

Error output building with v1.1 is like this:-

../cyfxbulksrcsink.c: In function 'CyFxBulkSrcSinkApplnUSBEventCB':
../cyfxbulksrcsink.c:536:14: error: 'CY_U3P_USB_EVENT_EP0_STAT_CPLT' undeclared (first use in this function)
../cyfxbulksrcsink.c:536:14: note: each undeclared identifier is reported only once for each function it appears in
../cyfxbulksrcsink.c: In function 'BulkSrcSinkAppThread_Entry':
../cyfxbulksrcsink.c:712:17: warning: implicit declaration of function 'CyU3PUsbSendDevNotification'
../cyfxbulksrcsink.c:714:17: warning: implicit declaration of function 'CyU3PUsbDoRemoteWakeup'

For latest SDK, please have a look at the last but one post in the below given thread:

http://www.cypress.com/?app=forum&id=167&rID=63875

Regards,

sai krishna.

Thanks. I (eventually) have the newer SDK and can build the code OK now.

However it does not seem to work.
So I added a CyU3PDebugPrint to the start of CyFxBulkSrcSinkApplnUSBSetupCB()

It seems that CyFxBulkSrcSinkApplnUSBSetupCB() only gets called once. Just once.

When it is called, bType =0, bTarget =0, bRequest =6, bReqType = 0x80

It does not appear to get called for the MS OS descriptor.

I carefully used regedit to delete

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\usbflags\------

And Windows thinks it has sent the 0xEE string request OK because afterwards it recreates the registry entry again.

And I can verify this behavior on anotehr (not FX3) device. In that case I see the 0xEE string request just fine. 

Any idea why this code is not seeing any more calls?

Oops. Ignore my last two posts. Sorry, I would unpost them if I could.

It seems your original code was correct... I misunderstood the way the FX3 API uses that bType parameter.

This OS descriptor request is indeed a    bType == CY_U3P_USB_STANDARD_RQT

and then the subsequent feature compatid requests are   bType == CY_U3P_USB_VENDOR_RQT

With that adjusted it seems to work now, even if I setup the callback with CyTrue as second param.

ie.     CyU3PUsbRegisterSetupCallback(CyFxBulkSrcSinkApplnUSBSetupCB, CyTrue);

Good to know that it is working at your end.