R820T2 Max VGA gain mod

Max VGA gain mod based on http://www.pabr.org/radio/leandvb-satmodem/leandvb-satmodem.en.html
mutability/rtl-sdr#2

Author: Mr-Precise

src/tuner_r82xx.c

@@ -1029,21 +1029,21 @@ int r82xx_set_gain(struct r82xx_priv *priv, int set_manual_gain, int gain)
 		uint8_t data[4];
 
 		/* LNA auto off */
-		rc = r82xx_write_reg_mask(priv, 0x05, 0x10, 0x10);
+		rc = r82xx_write_reg_mask(priv, 0x05, 0x04, 0x10);
 		if (rc < 0)
 			return rc;
 
 		 /* Mixer auto off */
-		rc = r82xx_write_reg_mask(priv, 0x07, 0, 0x10);
+		rc = r82xx_write_reg_mask(priv, 0x07, 0x04, 0x10);
 		if (rc < 0)
 			return rc;
 
 		rc = r82xx_read(priv, 0x00, data, sizeof(data));
 		if (rc < 0)
 			return rc;
 
-		/* set fixed VGA gain for now (16.3 dB) */
-		rc = r82xx_write_reg_mask(priv, 0x0c, 0x08, 0x9f);
+		/* set max VGA gain */
+		rc = r82xx_write_reg_mask(priv, 0x0c, 0x0f, 0x9f);
 		if (rc < 0)
 			return rc;
 
@@ -1070,17 +1070,17 @@ int r82xx_set_gain(struct r82xx_priv *priv, int set_manual_gain, int gain)
 			return rc;
 	} else {
 		/* LNA */
-		rc = r82xx_write_reg_mask(priv, 0x05, 0, 0x10);
+		rc = r82xx_write_reg_mask(priv, 0x05, 0x04, 0x10);
 		if (rc < 0)
 			return rc;
 
 		/* Mixer */
-		rc = r82xx_write_reg_mask(priv, 0x07, 0x10, 0x10);
+		rc = r82xx_write_reg_mask(priv, 0x07, 0x04, 0x10);
 		if (rc < 0)
 			return rc;
 
-		/* set fixed VGA gain for now (26.5 dB) */
-		rc = r82xx_write_reg_mask(priv, 0x0c, 0x0b, 0x9f);
+		/* set max VGA gain */
+		rc = r82xx_write_reg_mask(priv, 0x0c, 0x0f, 0x9f);
 		if (rc < 0)
 			return rc;
 	}