From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Richard Purdie" Subject: Re: FB_EVENT (blank and unblank?) Date: Sat, 27 Nov 2004 23:59:12 -0000 Message-ID: <027d01c4d4dd$19fe65a0$0f01a8c0@max> References: <41A36DA5.8090200@fujitsu-siemens.com> <010501c4d490$e9edee40$0f01a8c0@max> <200411280643.14171.adaplas@hotpop.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1CYCTJ-0006zi-Vn for linux-fbdev-devel@lists.sourceforge.net; Sat, 27 Nov 2004 15:59:21 -0800 Received: from tim.rpsys.net ([194.106.48.114] ident=0) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1CYCTE-0002Wr-9b for linux-fbdev-devel@lists.sourceforge.net; Sat, 27 Nov 2004 15:59:21 -0800 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; format="flowed"; charset="us-ascii"; reply-type="original" To: adaplas@pol.net, linux-fbdev-devel@lists.sourceforge.net Antonino A. Daplas: > On Saturday 27 November 2004 22:53, Richard Purdie wrote: >> I have two places where they need to talk. The first is for the touch >> screen to query the x resolution (and to know if the screen is >> blanked)[1]. >> The second is to turn the backlight off when the console is blanked. > > Can you adopt the backlight support infrastructure in powermacs? See > arch/ppc/platforms/pmac_backlight.c Currently, it's PPC-specific, but it > can be extended to other platforms. A few drivers use this, rivafb is one > of > them (drivers/video/fbdev.c), and aty. There are two issues here and this addresses the wrong one. My Issue: I have a backlight driver that shares no code with the framebuffer driver - the hardware is totally separate. I have there written them as two spate drivers which seems to make sense. The problem is that there is no method to communicate blanking to the external backlight driver (which is all it needs to know about). Obviously I can add links between them but I feel that's ugly. Adding a couple of extra events to the fb_register_client system would be much neater. The Other Issue: There is no common method to access and control backlight levels within the kernel. My feeling on this is that they should appear in sysfs as their own class. I need to look into this as I know there has been discussion in the past and I don't know what the issues are. I'd welcome any comments on this though. -- Richard ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/