viafb: add new funcions to select a single mode

This patch introduces 2 new functions for selecting a single mode
based on hres, vres and refresh rate and changes some uses to use
those. The advantage is that it is less error prone than doing the
selection based on refresh rate everywhere and allows replacing the
modetable structure. This includes a little change that users may
notice: If a refresh rate was given as module parameters but does
not exist in the modetable prior to this patch a refresh rate of 60
was assumed and after this patch the closest supported refresh rate
to the one provided by the user is used.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 43 insertions, 13 deletions

diff --git a/drivers/video/via/viamode.c b/drivers/video/via/viamode.c
index 8a9f4fc..88096e5 100644
--- a/drivers/video/via/viamode.c
+++ b/drivers/video/via/viamode.c
@@ -863,26 +863,56 @@ int NUM_TOTAL_CLE266_ModeXregs = ARRAY_SIZE(CLE266_ModeXregs);
 int NUM_TOTAL_PATCH_MODE = ARRAY_SIZE(res_patch_table);
 
 
-struct VideoModeTable *viafb_get_mode(int hres, int vres)
+static struct VideoModeTable *get_modes(struct VideoModeTable *vmt, int n,
+	int hres, int vres)
 {
-	u32 i;
-	for (i = 0; i < ARRAY_SIZE(viafb_modes); i++)
-		if (viafb_modes[i].mode_array &&
-			viafb_modes[i].crtc[0].crtc.hor_addr == hres &&
-			viafb_modes[i].crtc[0].crtc.ver_addr == vres)
+	int i;
+
+	for (i = 0; i < n; i++)
+		if (vmt[i].mode_array &&
+			vmt[i].crtc[0].crtc.hor_addr == hres &&
+			vmt[i].crtc[0].crtc.ver_addr == vres)
 			return &viafb_modes[i];
 
 	return NULL;
 }
 
+static struct crt_mode_table *get_best_mode(struct VideoModeTable *vmt,
+	int refresh)
+{
+	struct crt_mode_table *best;
+	int i;
+
+	if (!vmt)
+		return NULL;
+
+	best = &vmt->crtc[0];
+	for (i = 1; i < vmt->mode_array; i++) {
+		if (abs(vmt->crtc[i].refresh_rate - refresh)
+			< abs(best->refresh_rate - refresh))
+			best = &vmt->crtc[i];
+	}
+
+	return best;
+}
+
+struct VideoModeTable *viafb_get_mode(int hres, int vres)
+{
+	return get_modes(viafb_modes, ARRAY_SIZE(viafb_modes), hres, vres);
+}
+
+struct crt_mode_table *viafb_get_best_mode(int hres, int vres, int refresh)
+{
+	return get_best_mode(viafb_get_mode(hres, vres), refresh);
+}
+
 struct VideoModeTable *viafb_get_rb_mode(int hres, int vres)
 {
-	u32 i;
-	for (i = 0; i < ARRAY_SIZE(viafb_rb_modes); i++)
-		if (viafb_rb_modes[i].mode_array &&
-			viafb_rb_modes[i].crtc[0].crtc.hor_addr == hres &&
-			viafb_rb_modes[i].crtc[0].crtc.ver_addr == vres)
-			return &viafb_rb_modes[i];
+	return get_modes(viafb_rb_modes, ARRAY_SIZE(viafb_rb_modes), hres,
+		vres);
+}
 
-	return NULL;
+struct crt_mode_table *viafb_get_best_rb_mode(int hres, int vres, int refresh)
+{
+	return get_best_mode(viafb_get_rb_mode(hres, vres), refresh);
 }