From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753017Ab2D2OfY (ORCPT ); Sun, 29 Apr 2012 10:35:24 -0400 Received: from mail-yw0-f46.google.com ([209.85.213.46]:45414 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750896Ab2D2OfW (ORCPT ); Sun, 29 Apr 2012 10:35:22 -0400 MIME-Version: 1.0 In-Reply-To: <20381.15336.604590.461744@elektron.ikp.physik.tu-darmstadt.de> References: <1335632134-2488-1-git-send-email-preston.fick@silabs.com> <20120428190502.32eaf294@pyramind.ukuu.org.uk> <20380.13347.472373.965813@elektron.ikp.physik.tu-darmstadt.de> <20120428203322.7680594f@pyramind.ukuu.org.uk> <20381.15336.604590.461744@elektron.ikp.physik.tu-darmstadt.de> Date: Sun, 29 Apr 2012 22:35:21 +0800 Message-ID: Subject: Re: [PATCH] usb: cp210x: Added support for GPIO (CP2103/4/5) From: Xiaofan Chen To: Uwe Bonnes Cc: Alan Cox , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 29, 2012 at 9:02 PM, Uwe Bonnes wrote: > most RS232/USB Adapter don't supply and most applications working with these > adapters don't need hard realtime. So even writing and reading the serial > lines can be handled with libusb, like libftdi does. > > But as soon as higher level protocols based on the serial line get involved, > a kernel driver is needed... > > So when thinking some termiox, some thoughts for the FTDI special modes, > like MPSSE or synchronous FIFO should be spent. It would come handy if I > could open /dev/ttyUSBx, set som termiox and could use the kernel driver for > sending and receiving MPSSE commands. MPSSE is e.g. used in OpenOCD and > xc3sprog to talk e.g. JTAG to external devices. On the other hand, OpenOCD and your xc3sprog will probably remain to be cross-plattform and in that case libusb/libftdi is a good option to go. There is a patch under review in OpenOCD where libusb-1.0 is used for the MPSSE engine instead of libftdi/ftd2xx and the performance seems to be better. -- Xiaofan