drm/edid: Extract drm_gtf2_mode()

Extract the GTF vs. GTF2 logic into a separate function.
We'll have a second user soon.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220927170006.27855-5-ville.syrjala@linux.intel.com

drivers/gpu/drm/drm_edid.c

@@ -3113,6 +3113,35 @@ static int drm_mode_hsync(const struct drm_display_mode *mode)
 	return DIV_ROUND_CLOSEST(mode->clock, mode->htotal);
 }
 
+static struct drm_display_mode *
+drm_gtf2_mode(struct drm_device *dev,
+	      const struct drm_edid *drm_edid,
+	      int hsize, int vsize, int vrefresh_rate)
+{
+	struct drm_display_mode *mode;
+
+	/*
+	 * This is potentially wrong if there's ever a monitor with
+	 * more than one ranges section, each claiming a different
+	 * secondary GTF curve.  Please don't do that.
+	 */
+	mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
+	if (!mode)
+		return NULL;
+
+	if (drm_mode_hsync(mode) > drm_gtf2_hbreak(drm_edid)) {
+		drm_mode_destroy(dev, mode);
+		mode = drm_gtf_mode_complex(dev, hsize, vsize,
+					    vrefresh_rate, 0, 0,
+					    drm_gtf2_m(drm_edid),
+					    drm_gtf2_2c(drm_edid),
+					    drm_gtf2_k(drm_edid),
+					    drm_gtf2_2j(drm_edid));
+	}
+
+	return mode;
+}
+
 /*
  * Take the standard timing params (in this case width, aspect, and refresh)
  * and convert them into a real mode using CVT/GTF/DMT.
@@ -3201,23 +3230,7 @@ static struct drm_display_mode *drm_mode_std(struct drm_connector *connector,
 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
 		break;
 	case LEVEL_GTF2:
-		/*
-		 * This is potentially wrong if there's ever a monitor with
-		 * more than one ranges section, each claiming a different
-		 * secondary GTF curve.  Please don't do that.
-		 */
-		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
-		if (!mode)
-			return NULL;
-		if (drm_mode_hsync(mode) > drm_gtf2_hbreak(drm_edid)) {
-			drm_mode_destroy(dev, mode);
-			mode = drm_gtf_mode_complex(dev, hsize, vsize,
-						    vrefresh_rate, 0, 0,
-						    drm_gtf2_m(drm_edid),
-						    drm_gtf2_2c(drm_edid),
-						    drm_gtf2_k(drm_edid),
-						    drm_gtf2_2j(drm_edid));
-		}
+		mode = drm_gtf2_mode(dev, drm_edid, hsize, vsize, vrefresh_rate);
 		break;
 	case LEVEL_CVT:
 		mode = drm_cvt_mode(dev, hsize, vsize, vrefresh_rate, 0, 0,