From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261735AbVBOOIq (ORCPT ); Tue, 15 Feb 2005 09:08:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261734AbVBOOIq (ORCPT ); Tue, 15 Feb 2005 09:08:46 -0500 Received: from smtpout16.mailhost.ntl.com ([212.250.162.16]:30540 "EHLO mta08-winn.mailhost.ntl.com") by vger.kernel.org with ESMTP id S261727AbVBOOIi (ORCPT ); Tue, 15 Feb 2005 09:08:38 -0500 Subject: Re: What is the purpose of a GPIO controller From: Ian Campbell To: krishna Cc: Linux Kernel In-Reply-To: <4211FDFC.3040905@globaledgesoft.com> References: <4211FDFC.3040905@globaledgesoft.com> Content-Type: text/plain Date: Tue, 15 Feb 2005 14:08:33 +0000 Message-Id: <1108476513.3324.10.camel@icampbell-debian> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2005-02-15 at 19:19 +0530, krishna wrote: > Can any one tell me what is the purpose of GPIO controllers. I'm not sure what question you are asking... GPIO controllers are clearly for the purpose of controlling GPIO pins. GPIO stands for general purpose i/o, so they are used for all sorts of things. For example, hardware designers hook up all sorts of things to GPIO lines: input switches, reset lines to other chips on the board, leds, relays. I have boards where an i2c bus has been constructed using 2 gpio lines, another gpio is used to control the LCD backlight, etc, etc. Ian. -- Ian Campbell Current Noise: Opeth - To Rid the Disease The pollution's at that awkward stage. Too thick to navigate and too thin to cultivate. -- Doug Sneyd