From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030285AbXDKAar (ORCPT ); Tue, 10 Apr 2007 20:30:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932411AbXDKAar (ORCPT ); Tue, 10 Apr 2007 20:30:47 -0400 Received: from nz-out-0506.google.com ([64.233.162.236]:60496 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932359AbXDKAaq (ORCPT ); Tue, 10 Apr 2007 20:30:46 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Jd3ybN5xGV5OUnsY2tD19gpI3G8vVxZJ0Wl53s/HbDirAg+XBo60xzpoSIsVWJoye4FFXpQTGXg0sjmRuGX0G4FvANGyhsv8EfLuLhghlGoWy8B39/3AHgFuYJ1RhD3UqBqXKhmxddFMeZJk0sFjQlegZpQ0YWOjnQ7LjwJzS98= Message-ID: Date: Wed, 11 Apr 2007 08:30:45 +0800 From: "Eric Miao" To: "Paul Sokolovsky" Subject: Re: [RFC, PATCH 1/3] gpiodev - API definitions Cc: linux-arm-kernel@lists.arm.linux.org.uk, linux-kernel@vger.kernel.org In-Reply-To: <774343545.20070411003058@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <774343545.20070411003058@gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org it looks ok, but I have several questions: 1. why should we bind this to platform_device, what if the gpio device is not actually a "platform_device", say, a I2C device, a SPI device or even a USB device? 2. I still doubt the benefit of using of a structure for a gpio, isn't a gpio number not enough? 3. If one is going to use a GPIO, he has to initialize a "struct gpio" before that, how is he suppose to know the value for "gpio->gpio_dev"? 4. how can we optimize to a direct register access instruction (e.g. to GPDR in PXA) for bit-banging operation (pardon me, I don't exactly remember the name for such operation, maybe bit-banging)