rt2800: radio 3xxx: program RF_R1 during channel switch

Synchronize code with Ralink driver:
2011_0719_RT3070_RT3370_RT5370_RT5372_Linux_STA_V2.5.0.3_DPO
Based on functions:
RT33xx_ChipSwitchChannel
RT30xx_ChipSwitchChannel
RT33xx_Init
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -1665,6 +1665,40 @@ static void rt2800_config_channel_rf3xxx(struct rt2x00_dev *rt2x00dev,
 	rt2x00_set_field8(&rfcsr, RFCSR13_TX_POWER, info->default_power2);
 	rt2800_rfcsr_write(rt2x00dev, 13, rfcsr);
 
+	rt2800_rfcsr_read(rt2x00dev, 1, &rfcsr);
+	rt2x00_set_field8(&rfcsr, RFCSR1_RX0_PD, 0);
+	rt2x00_set_field8(&rfcsr, RFCSR1_TX0_PD, 0);
+	if (rt2x00_rt(rt2x00dev, RT3390)) {
+		rt2x00_set_field8(&rfcsr, RFCSR1_RX1_PD,
+				  rt2x00dev->default_ant.rx_chain_num == 1);
+		rt2x00_set_field8(&rfcsr, RFCSR1_TX1_PD,
+				  rt2x00dev->default_ant.tx_chain_num == 1);
+	} else {
+		rt2x00_set_field8(&rfcsr, RFCSR1_RX1_PD, 0);
+		rt2x00_set_field8(&rfcsr, RFCSR1_TX1_PD, 0);
+		rt2x00_set_field8(&rfcsr, RFCSR1_RX2_PD, 0);
+		rt2x00_set_field8(&rfcsr, RFCSR1_TX2_PD, 0);
+
+		switch (rt2x00dev->default_ant.tx_chain_num) {
+		case 1:
+			rt2x00_set_field8(&rfcsr, RFCSR1_TX1_PD, 1);
+			/* fall through */
+		case 2:
+			rt2x00_set_field8(&rfcsr, RFCSR1_TX2_PD, 1);
+			break;
+		}
+
+		switch (rt2x00dev->default_ant.rx_chain_num) {
+		case 1:
+			rt2x00_set_field8(&rfcsr, RFCSR1_RX1_PD, 1);
+			/* fall through */
+		case 2:
+			rt2x00_set_field8(&rfcsr, RFCSR1_RX2_PD, 1);
+			break;
+		}
+	}
+	rt2800_rfcsr_write(rt2x00dev, 1, rfcsr);
+
 	rt2800_rfcsr_read(rt2x00dev, 23, &rfcsr);
 	rt2x00_set_field8(&rfcsr, RFCSR23_FREQ_OFFSET, rt2x00dev->freq_offset);
 	rt2800_rfcsr_write(rt2x00dev, 23, rfcsr);