r82xx: direct sampling fixes from tejeez

src/tuner_r82xx.c

@@ -946,7 +946,7 @@ static int r82xx_set_if_filter(struct r82xx_priv *priv, int hpf, int lpf) {
 	else if(cal > 15) cal = 15;
 	priv->fil_cal_code = cal;
 
-	fprintf(stderr, "Setting IF filter for %d...%d kHz: hp_cor=0x%02x, fil_cal_code=%d\n", hpf, lpf, hp_cor, cal);
+	//fprintf(stderr, "Setting IF filter for %d...%d kHz: hp_cor=0x%02x, fil_cal_code=%d\n", hpf, lpf, hp_cor, cal);
 
 	rc = r82xx_write_reg_mask(priv, 0x0a,
 				  filt_q | priv->fil_cal_code, 0x1f);
@@ -1113,17 +1113,22 @@ int r82xx_set_nomod(struct r82xx_priv *priv)
 
 	fprintf(stderr, "Using R820T no-mod direct sampling mode\n");
 
-	/*rc = r82xx_set_bw(priv, 1000000);
-	if (rc < 0)
-		goto err;*/
+	/* should probably play a bit more with the mux settings
+	    to see if something works even better than this */
 
-	/* experimentally determined magic numbers
-	 * needs more experimenting with all the registers */
 	rc = r82xx_set_mux(priv, 300000000);
-	if (rc < 0)
-		goto err;
+	if (rc < 0) goto err;
 
-	r82xx_set_pll(priv, 25000000);
+	/* the VCO frequency setting still seems to have some effect on the noise floor */
+	rc = r82xx_set_pll(priv, 50000000);
+	if (rc < 0) goto err;
+
+	/* the most important part: set a divider number that does not really work */
+	rc = r82xx_write_reg_mask(priv, 0x10, 0xd0, 0xe0);
+	if (rc < 0) goto err;
+
+	/* VCO power off? */
+	rc = r82xx_write_reg_mask(priv, 0x12, 0xe0, 0xe0);
 
 err:
 	if (rc < 0)