USB CCID class with nordic nRF52840

[Mohammad]

I am developing USB CCID driver class for nordic nRF52840. I used USB CDC-ACM class as reference and tried to implement for USB CCID. I have developed the device descriptor for it.

USB CCID class has 1 interface and 3 endpoints(1 for interrupt, 1 for bulk IN and 1 for bulk OUT). Now the windows is detecting as Microsoft Usbccid smart card reader(WUDF)

In modify the app_usbd_ccid_internal.h, i need to know modification to be done in 

1. class instance data (app_usbd_ccid_inst_t)

2. CCID class specific request handled via control endpoint (app_usbd_ccid_req_t)

3.  ccid context (app_usbd_ccid_ctx_t)

I have attached my app_usbd_ccid_internal.h file with tis for refrence.

app_usbd_ccid_internal.h

[Håkon Alseth]

Hi,

 

This is a windows feature, that you cannot fix in firmware.

See a similar issue here, just for the USBD_CDC_ACM: https://devzone.nordicsemi.com/f/nordic-q-a/52438/usb-cdc-uart-is-recognized-as-teensy-com-port

If you have another driver, you can manually update the driver, as described in the above link.

 

Kind regards,

Håkon

[Mohammad]

Hi Håkon,

This is not the answer for the issue i described above.

Pls check above issue i have described. 

[Håkon Alseth]

Hi,

 

I am sorry if I have misunderstood. From your text, I read that the windows driver enumeration (more specifically; the driver name) is the issue. Is that not the case? If not, can you please describe more in detail?

Kind regards,

Håkon

[Mohammad]

Hi Håkon,

I am developing USB CCID driver class which not exist in nRF52 SDK. 

Nordic guy (kenneth) refer me to use USB CDC-ACM class as reference for developing USB CCID class driver.

https://devzone.nordicsemi.com/f/nordic-q-a/38402/need-support-for-usb-ccid-using-nrf52840

I have modified all the USB CDC class files in order to detect as USB CCID. Files are,
1. app_usbd_ccid_types.h
2. app_usbd_ccid_internals.h
3. app_usbd_ccid_desc.h
4. app_usbd_ccid.h
5. app_usbd_ccid.c

I have successfully written the Interface and class descriptor for CCID and I have tested it. Now the windows shows correctly Microsoft usbccid smart card reader(WUDF).

Now I need to modify further more in order to finish the USB CCID class driver. So i need to know parameter details of

1. usb class instant data (app_usbd_class_inst_t) (Here class will be cdc or audio or msc or HID, in my case it is ccid, app_usbd_ccid_inst_t).

2. class context( app_usbd_class_ctx_t,  Here class will be cdc or audio or msc or HID, in my case it is ccid, app_usbd_ccid_ctx_t).

3. class specific request handled via control endpoint ( app_usbd_class_req_t,  Here class will be cdc or audio or msc or HID, in my case it is ccid, app_usbd_ccid_req_t).

I have attached my app_usbd_ccid_internal.h file for your refrence.(above)

[Håkon Alseth]

Hi,

Mohammad said:

Now I need to modify further more in order to finish the USB CCID class driver. So i need to know parameter details of

1. usb class instant data (app_usbd_class_inst_t) (Here class will be cdc or audio or msc or HID, in my case it is ccid, app_usbd_ccid_inst_t).

2. class context( app_usbd_class_ctx_t,  Here class will be cdc or audio or msc or HID, in my case it is ccid, app_usbd_ccid_ctx_t).

3. class specific request handled via control endpoint ( app_usbd_class_req_t,  Here class will be cdc or audio or msc or HID, in my case it is ccid, app_usbd_ccid_req_t).

Unfortunately, we do not have a document/guide specifically on how to create a own usb class.

The parameters you're asking for is defined in the USB CCID class itself, which you can find here: https://www.usb.org/sites/default/files/DWG_Smart-Card_CCID_Rev110.pdf.

To implement these into the USBD framework, I would recommend looking at the already present classes, and the documentation for USBD:

https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/lib_usbd.html?cp=6_1_3_60

 

Kind regards,

Håkon

[Mohammad]

Hi,

Thanks for your response.

Can you let me know how to receive the data from the specific endpoint.

[Håkon Alseth]

Hi,

 

When using app_usbd, see the event handler, in case of the cdc, cdc_acm_event_handler, case "APP_USBD_EVT_DRV_EPTRANSFER".

Kind regards,

Håkon

[Mohammad]

Hi,

Thanks for your response.

Can you specify your answer more clearly where i can refer in the cdc code for receive the data from endpoint.

For example, to send the data in endpoint(EP0), i use the following code,

ret_code_t ret;
nrf_drv_usbd_transfer_t transfer =
{
   .p_data = {.tx = p_data},
   .size = size
};
ret = nrf_drv_usbd_ep_transfer(NRF_DRV_USBD_EPIN0, &transfer);

As per your above statement, once the NRF_DRV_USBD_EVT_EPTRANSFER event is generated, it calls cdc_acm_endpoint_ev where the type of endpoint is check.

If it is bulkout endpoint, cdc_acm_rx_block_finished is called once the NRF_USBD_EP_OK is OK.

But i need to know how to copy the data from the endpoint.

[Håkon Alseth]

Hi,

  

Mohammad said:

ret = nrf_drv_usbd_ep_transfer(NRF_DRV_USBD_EPIN0, &transfer);

In that function, you check if it is IN or OUT direction, based on the EP.

In the case of the cdc_acm, it uses the app_usbd_ep_handled_transfer(), which schedules a callback just prior to when the transfer is to occur, as per the header documentation in nrfx_usbd.h:

/**
 * @brief Start sending data over the endpoint using the transfer handler function.
 *
 * This function initializes an endpoint transmission.
 * Just before data is transmitted, the transfer handler
 * is called and it prepares a data chunk.
 *
 * @param[in] ep        Endpoint number.
 *                      For an IN endpoint, sending is initiated.
 *                      For an OUT endpoint, receiving is initiated.
 * @param[in] p_handler Transfer handler - feeder for IN direction and consumer for
 *                      OUT direction.
 *
 * @retval NRFX_SUCCESS             Transfer queued or started.
 * @retval NRFX_ERROR_BUSY          Selected endpoint is pending.
 * @retval NRFX_ERROR_INVALID_ADDR  Unexpected transfer on EPIN0 or EPOUT0.
 */
nrfx_err_t nrfx_usbd_ep_handled_transfer(nrfx_usbd_ep_t ep,
                                         nrfx_usbd_handler_desc_t const * p_handler);

You can also fetch this using app_usbd_ep_transfer() (for both directions, filtered on the input EP).

  

Mohammad said:

If it is bulkout endpoint, cdc_acm_rx_block_finished is called once the NRF_USBD_EP_OK is OK.

But i need to know how to copy the data from the endpoint.

  That specific function has CDC specific buffering logic, which makes it complicated wrt. where the USB data is read. It's essentially the call to "app_usbd_ep_handled_transfer" that handles it. The rest is buffer logic.

 

Kind regards,

Håkon