rt2x00: rt2800lib: add BBP register initialization for RT3593

Based on the Ralink DPO_RT5572_LinuxSTA_2.6.0.1_20120629
driver.

References:
  NICInitRT3593BbpRegisters in chips/rt3593.c
  NICInitBBP in common/rtmp_init.c
  NICInitAsicFromEEPROM in common/rtmp_init.c
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Acked-by: NStanislaw Gruszka <stf_xl@wp.pl>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -4504,6 +4504,22 @@ static void rt2800_init_bbp_3572(struct rt2x00_dev *rt2x00dev)
 	rt2800_disable_unused_dac_adc(rt2x00dev);
 }
 
+static void rt2800_init_bbp_3593(struct rt2x00_dev *rt2x00dev)
+{
+	rt2800_init_bbp_early(rt2x00dev);
+
+	rt2800_bbp_write(rt2x00dev, 79, 0x13);
+	rt2800_bbp_write(rt2x00dev, 80, 0x05);
+	rt2800_bbp_write(rt2x00dev, 81, 0x33);
+	rt2800_bbp_write(rt2x00dev, 137, 0x0f);
+
+	rt2800_bbp_write(rt2x00dev, 84, 0x19);
+
+	/* Enable DC filter */
+	if (rt2x00_rt_rev_gte(rt2x00dev, RT3593, REV_RT3593E))
+		rt2800_bbp_write(rt2x00dev, 103, 0xc0);
+}
+
 static void rt2800_init_bbp_53xx(struct rt2x00_dev *rt2x00dev)
 {
 	int ant, div_mode;
@@ -4719,6 +4735,9 @@ static void rt2800_init_bbp(struct rt2x00_dev *rt2x00dev)
 	case RT3572:
 		rt2800_init_bbp_3572(rt2x00dev);
 		break;
+	case RT3593:
+		rt2800_init_bbp_3593(rt2x00dev);
+		return;
 	case RT5390:
 	case RT5392:
 		rt2800_init_bbp_53xx(rt2x00dev);