From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Richard Purdie" Subject: Re: FB_EVENT (blank and unblank?) Date: Sun, 28 Nov 2004 00:59:02 -0000 Message-ID: <02cc01c4d4e5$75e4e170$0f01a8c0@max> References: <41A36DA5.8090200@fujitsu-siemens.com> <200411280643.14171.adaplas@hotpop.com> <027d01c4d4dd$19fe65a0$0f01a8c0@max> <200411280824.01338.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 1CYDPE-0001gT-QE for linux-fbdev-devel@lists.sourceforge.net; Sat, 27 Nov 2004 16:59:12 -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 1CYDP4-0003rU-P7 for linux-fbdev-devel@lists.sourceforge.net; Sat, 27 Nov 2004 16:59:12 -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: >> 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 > > Of course there is. Your backlight driver does a > register_backlight_controllers(). Then your fb driver does a > set_backlight_enable(!blank) in its xxxfb_blank implementation. Yes, you could do that. I was trying to look for a method than meant no specific action by the framebuffer driver was required. It shouldn't have to care if a backlight is present or not... On the other hand, the console system shouldn't have to either. Hence the suggestion that blank and unblank events are added. It may be there's a layer of backlight glue added to the drivers/video directory drivers/video/backlight? that catches those events and calls set_backlight_enable(!blank) and provides functions like register_backlight_controllers(). >> The Other Issue: There is no common method to access and control >> backlight > > Not yet, but if the powermac backlight support is extended, then we > suddenly > have a common method. Right now, pmac's backlight support has this as > exportable symbols: > > set_backlight_enable() > get_backlight_enable() > set_backlight_level() > get_backlight_level() > > And all of the above calls specific hooks to the backlight driver. I agree that would go part of the way towards a common method (the other part being a sysfs representation or similar). That sysfs representation could even be provided by backlight "core" in drivers/video/backlight?. > We don't have a common architecture yet for backlight control, and I don't > know where this is really going. Anyone here have more info? I'd be interested to know the current position... 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/