Re: Forcing a USB device to "ugen"

[Jason Thorpe <thorpej%me.com@localhost>]

> On Mar 26, 2024, at 5:37 AM, Robert Swindells <rjs%fdy2.co.uk@localhost> wrote:
> 
> I thought that all FTDI devices provided JTAG etc. functionality, just
> that the pins are not connected to anything in some devices.

I guess it depends on how your individual FTDI board is wired up.  Also, for chips without the MPSSE, you need something else.  OpenOCD supports JTAG over the FT232R, for example, by bit-banging  with the various RS232 signals (RXD, TXD, RTS, CTS, DTR, DCD).

Anyway, as I noted in my original email, my particular board has one of the 2232 interfaces intended for use as a UART (and connected to a header that labels it for that purpose), and the second interface brought out two 4 different headers labeled for JTAG, SWD, SPI, and I2C.

> What would be wrong with attaching an ugen to interface 1 instead of
> an ucom in the ftdi driver itself?

ugen can’t currently attach to things other than uhub.  I think attaching ugen as the leaf is the wrong model, though; ugen should be what the kernel drivers themselves attach to, IMO.

-- thorpej