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pickmode.c revision 1.2 
      1 /* $NetBSD: pickmode.c,v 1.2 2010/10/12 16:18:19 macallan Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2006 The NetBSD Foundation
      5  * All rights reserved.
      6  *
      7  * this code was contributed to The NetBSD Foundation by Michael Lorenz
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  *
     18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS
     19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE NETBSD FOUNDATION BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     24  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     27  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 __KERNEL_RCSID(0, "$NetBSD: pickmode.c,v 1.2 2010/10/12 16:18:19 macallan Exp $");
     33 
     34 #include <sys/param.h>
     35 #include <dev/videomode/videomode.h>
     36 #include "opt_videomode.h"
     37 
     38 #ifdef PICKMODE_DEBUG
     39 #define DPRINTF printf
     40 #else
     41 #define DPRINTF while (0) printf
     42 #endif
     43 
     44 const struct videomode *
     45 pick_mode_by_dotclock(int width, int height, int dotclock)
     46 {
     47 	const struct videomode *this, *best = NULL;
     48 	int i;
     49 
     50 	DPRINTF("%s: looking for %d x %d at up to %d kHz\n", __func__, width,
     51 	    height, dotclock);
     52 	for (i = 0; i < videomode_count; i++) {
     53 
     54 		this = &videomode_list[i];
     55 		if ((this->hdisplay != width) || (this->vdisplay != height) ||
     56 		    (this->dot_clock > dotclock))
     57 			continue;
     58 		if (best != NULL) {
     59 
     60 			if (this->dot_clock > best->dot_clock)
     61 				best = this;
     62 		} else
     63 			best = this;
     64 	}
     65 	if (best!= NULL)
     66 		DPRINTF("found %s\n", best->name);
     67 
     68 	return best;
     69 }
     70 
     71 const struct videomode *
     72 pick_mode_by_ref(int width, int height, int refresh)
     73 {
     74 	const struct videomode *this, *best = NULL;
     75 	int mref, closest = 1000, i, diff;
     76 
     77 	DPRINTF("%s: looking for %d x %d at up to %d Hz\n", __func__, width,
     78 	    height, refresh);
     79 	for (i = 0; i < videomode_count; i++) {
     80 
     81 		this = &videomode_list[i];
     82 		mref = this->dot_clock * 1000 / (this->htotal * this->vtotal);
     83 		diff = abs(mref - refresh);
     84 		if ((this->hdisplay != width) || (this->vdisplay != height))
     85 			continue;
     86 		DPRINTF("%s in %d hz, diff %d\n", this->name, mref, diff);
     87 		if (best != NULL) {
     88 
     89 			if (diff < closest) {
     90 
     91 				best = this;
     92 				closest = diff;
     93 			}
     94 		} else {
     95 			best = this;
     96 			closest = diff;
     97 		}
     98 	}
     99 	if (best!= NULL)
    100 		DPRINTF("found %s %d\n", best->name, best->dot_clock);
    101 
    102 	return best;
    103 }
    104