[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: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/video/modedb.c b/drivers/video/modedb.c
index aadef04..1789a52 100644
--- a/drivers/video/modedb.c
+++ b/drivers/video/modedb.c
@@ -944,6 +944,66 @@
}
}
+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);