# FreeBSD USB equivalent to Linux usb_control_msg



## Need4Speed (Aug 28, 2010)

Hi,

Can anyone clarify how to go about doing a synchronous usb control transfer, similar to Linux's *usb_control_msg*? I want to implement the TIOCMGET ioctl on a usb-to-serial converter. The Linux driver uses synchronous control messages to read DCE and CTS serial pin status, and I want to do something similar in FreeBSD. The usbdi(9) manpage talks about control transfers using *usbd_transfer_submit*, but they don't look synchronous to me. What about using *usbd_transfer_drain*? Is there a better way to do this in FreeBSD?

Thanks


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## graudeejs (Aug 28, 2010)

You better ask this on mailinglist.
Causal users won't be able help you... what you need is some developer.... (not many read this forum)


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