From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ico Doornekamp Subject: Re: Questions about fbdriver integration Date: Sun, 25 Nov 2007 11:51:53 +0100 Message-ID: <20071125105153.GH3183@pruts.nl> References: <20071124214325.GD3183@pruts.nl> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1IwF5q-0005SM-Nq for linux-fbdev-devel@lists.sourceforge.net; Sun, 25 Nov 2007 02:52:06 -0800 Received: from pruts.nl ([82.94.235.106] helo=iron.pruts.nl ident=postfix) by mail.sourceforge.net with esmtp (Exim 4.44) id 1IwF5q-0000zI-6d for linux-fbdev-devel@lists.sourceforge.net; Sun, 25 Nov 2007 02:52:06 -0800 Received: from localhost (localhost.localdomain [127.0.0.1]) by iron.pruts.nl (Postfix) with ESMTP id 0528412E42C for ; Sun, 25 Nov 2007 11:52:04 +0100 (CET) Received: from iron.pruts.nl ([127.0.0.1]) by localhost (iron.pruts.nl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9IyIGOuKWMCl for ; Sun, 25 Nov 2007 11:51:54 +0100 (CET) Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: linux-fbdev-devel@lists.sourceforge.net * On 2007-11-25 Geert Uytterhoeven wrote : > On Sat, 24 Nov 2007, Ico Doornekamp wrote: > > I have just finished writing a framebuffer driver for a LCD display > > connected to our embedded system (monochrome, 128x64, GPIO driven). > > It's very similar to the hecubafb driver, and uses deferred IO. I've > > included some of the drivers properties at the end of this mail. Things > > works fine when displaying images by doing write()s to /dev/fb0, so this > > part seems to be ok. > > > > I hope some of the regulars on this list can clear up some issues > > I've run into when using this driver: > > > > - My next step as to redirect the linux console to this framebuffer > > device. I've configured the kernel for framebuffer console, and when > > loading the fbcon module, the message > > > > Console: switching to mono frame buffer device 16x4" > > > > appears, and > > > > cat /sys/class/vtconsole/vtcon1/name -> (M) frame buffer device > > cat /sys/class/vtconsole/vtcon1/bind -> 1 > > > > This seems just fine to me, but however, no output appears on the > > display: just a blank screen. > > > > It seems that the console is doing *something*, since my driver gets > > triggered by the deferred IO every 200msec (blinking cursor?), problem > > is that the data arriving in my driver is all zeroes! > > Fbcon writes to the memory at fb_info.screen_base. That is what I expected. I'll have to do a bit more debugging here then. > > - The other question is more a userspace issue: I was hoping to use the > > xorg fbdev server on my dislay, but unfortunately this does not seem > > to support 1 bit depth displays : > > > > (EE) FBDEV(0): unsupported number of bits per pixel: 1 > > > > Is there a way to make X work on 1-bit fb devices, or am I out of luck > > here ? > > The old XF86_FBDev (from XFree86 3.x) definitely works with monochrome. > I expect (but never tried) KDrive also to support it. > > It's a pity many frame buffer organizations were dropped in Xorg. It is, yes. I'll give Kdrive a try, or as an alternative I can make my framebuffer 8-bit greycale instead of monochrome, with a simple threshold. I'll be using simple monochrome apps with some text only, so that will probably be sufficient. Thanks, Ico -- :wq ^X^Cy^K^X^C^C^C^C ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/