From mboxrd@z Thu Jan 1 00:00:00 1970 From: greg@kroah.com (Greg KH) Date: Mon, 21 Jul 2014 12:46:35 -0700 Subject: usb serial programming In-Reply-To: References: <20140721181828.GA9397@kroah.com> <20140721190643.GA13587@kroah.com> Message-ID: <20140721194635.GA29605@kroah.com> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Mon, Jul 21, 2014 at 07:25:24PM +0000, Amadeus W.M. wrote: > > > > What is the: > > Bus 004 Device 008: ID 0764:0501 Cyber Power System, Inc. CP1500 AVR UPS > > > > device? > > That's my backup power supply. > > > > > >> Should /dev/ttyUSB0 pop up when I plug the adapter into the usb port, > >> even before I connect anything to the serial port of the cable? > > > > Yes. > > > > What happens in the kernel log when you plug the device into the system? > > > > Try doing: > > dmesg -c > > # plug in the adapter now > > dmesg > > to just see the log messages for that, and not the whole kernel boot > > log. > > > 2) root:~> dmesg -c #plug-in adapter > 3) root:~> dmesg > > Absolutely nothing. I also did > > tail -f /var/log/messages Then USB isn't working :( Or the device isn't, can you plug it into some other computer to test it out? > then plugged in the adapter, and again, everything seems dead. The USB port > is ok, because other devices (e.g. the Fushicai video grabber) do work. Sounds like a broken device. > >> If the adapter is not supported, can I write a driver for it? I'll be happy to, > >> with a little guidance to get me started. Any pointers? > > > > Odds are the device id just needs to be added to an existing driver as > > I do not know of any "new" usb-serial converter chips that Linux does > > not already support. > > > > Oh, one more thing. Reading about these converters, I saw many use an > ftdi chip, so I did modprobed ftdi_elan and ftdi_sio: > > 7) root:~> lsmod | grep ftdi > ftdi_elan 36689 0 > ftdi_sio 48770 0 > > In fact, the dmesg above was with the ftdi modules loaded. You should get some kernel log messages when a new USB device is plugged in, no matter what type it is. The fact that you are not is a problem. greg k-h