Commit 003cfc0c authored by Antonino A. Daplas's avatar Antonino A. Daplas Committed by Linus Torvalds
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[PATCH] fbdev: Add helper to get an appropriate initial mode 



Add new helper, fb_find_best_display(), which will search the modelist for the
best mode for the attached display.  This requires an EDID block that is
converted to struct fb_monspecs and a private modelist.  The search will be
done in this manner:

- if 1st detailed timing is preferred, use that
- else if dimensions of the display are known, use that to estimate xres and
- else if modelist has detailed timings, use the first detailed timing
- else, use the very first entry from the modelist

Signed-off-by: default avatarAntonino Daplas <adaplas@pol.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 14c8102f

drivers/video/modedb.c

+60 −0
Original line number Diff line number Diff line
@@ -944,6 +944,66 @@ void fb_videomode_to_modelist(struct fb_videomode *modedb, int num, 
	}

}



struct fb_videomode *fb_find_best_display(struct fb_monspecs *specs,

					  struct list_head *head)

{

	struct list_head *pos;

	struct fb_modelist *modelist;

	struct fb_videomode *m, *m1 = NULL, *md = NULL, *best = NULL;

	int first = 0;



	if (!head->prev || !head->next || list_empty(head))

		goto finished;



	/* get the first detailed mode and the very first mode */

	list_for_each(pos, head) {

		modelist = list_entry(pos, struct fb_modelist, list);

		m = &modelist->mode;



		if (!first) {

			m1 = m;

			first = 1;

		}



		if (m->flag & FB_MODE_IS_FIRST) {

 			md = m;

			break;

		}

	}



	/* first detailed timing is preferred */

	if (specs->misc & FB_MISC_1ST_DETAIL) {

		best = md;

		goto finished;

	}



	/* find best mode based on display width and height */

	if (specs->max_x && specs->max_y) {

		struct fb_var_screeninfo var;



		memset(&var, 0, sizeof(struct fb_var_screeninfo));

		var.xres = (specs->max_x * 7200)/254;

		var.yres = (specs->max_y * 7200)/254;

		m = fb_find_best_mode(&var, head);

		if (m) {

			best = m;

			goto finished;

		}

	}



	/* use first detailed mode */

	if (md) {

		best = md;

		goto finished;

	}



	/* last resort, use the very first mode */

	best = m1;

finished:

	return best;

}

EXPORT_SYMBOL(fb_find_best_display);



EXPORT_SYMBOL(fb_videomode_to_var);

EXPORT_SYMBOL(fb_var_to_videomode);

EXPORT_SYMBOL(fb_mode_is_equal);

include/linux/fb.h

+2 −0
Original line number Diff line number Diff line
@@ -902,6 +902,8 @@ extern struct fb_videomode *fb_find_nearest_mode(struct fb_videomode *mode, 
extern void fb_destroy_modelist(struct list_head *head);

extern void fb_videomode_to_modelist(struct fb_videomode *modedb, int num,

				     struct list_head *head);

extern struct fb_videomode *fb_find_best_display(struct fb_monspecs *specs,

						 struct list_head *head);



/* drivers/video/fbcmap.c */

extern int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp);

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