From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Subject: Re: [PATCH 3.9] Driver for 7-segment displays connected over GPIOs Date: Mon, 7 Jan 2013 18:43:52 +0100 Message-ID: <20130107184352.2e90abfb@skate> References: <1357576928-29133-1-git-send-email-thomas.petazzoni@free-electrons.com> <20130107164845.GA2911@kroah.com> <20130107180708.2ffc1540@skate> <20130107172340.GA32401@kroah.com> <20130107184022.72b23aa9@skate> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130107184022.72b23aa9@skate> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Greg Kroah-Hartman Cc: Lior Amsalem , Andrew Lunn , Jason Cooper , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Mon, 7 Jan 2013 18:40:22 +0100, Thomas Petazzoni wrote: > > > Not having a kernel driver means that gazillions of applications > > > re-invent the same piece of code over and over again, have to hardcode > > > the GPIO numbers for a given piece of hardware, while the kernel > > > abstract all of this very nicely. > > > > That sounds like a wonderful use of a userspace library to do this > > properly. Much like libusb does, right? > > > > I still think as this can be done in userspace, it probably should be. > > Understood. Patches discarded. Thinking more about this. How would your userspace library know on which GPIOs your 7-seg segment device is connected? Should it parse the Device Tree from userspace? Given by the user-space application who would have to hardcode the GPIO numbers, completely defeating the hardware abstraction layer that the kernel intends to be? Thanks, Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com