--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -721,6 +721,7 @@ struct ath_spec_scan {
  * @config_pci_powersave:
  * @calibrate: periodic calibration for NF, ANI, IQ, ADC gain, ADC-DC
  *
+ * @get_adc_entropy: get entropy from the raw ADC I/Q output
  * @spectral_scan_config: set parameters for spectral scan and enable/disable it
  * @spectral_scan_trigger: trigger a spectral scan run
  * @spectral_scan_wait: wait for a spectral scan run to finish
@@ -743,6 +744,7 @@ struct ath_hw_ops {
 			struct ath_hw_antcomb_conf *antconf);
 	void (*antdiv_comb_conf_set)(struct ath_hw *ah,
 			struct ath_hw_antcomb_conf *antconf);
+	void (*get_adc_entropy)(struct ath_hw *ah, u8 *buf, size_t len);
 	void (*spectral_scan_config)(struct ath_hw *ah,
 				     struct ath_spec_scan *param);
 	void (*spectral_scan_trigger)(struct ath_hw *ah);
--- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
@@ -1947,6 +1947,26 @@ void ar9003_hw_init_rate_txpower(struct
 	}
 }
 
+static void ar9003_hw_get_adc_entropy(struct ath_hw *ah, u8 *buf, size_t len)
+{
+	int i, j;
+
+	REG_RMW_FIELD(ah, AR_PHY_TEST, AR_PHY_TEST_BBB_OBS_SEL, 1);
+	REG_CLR_BIT(ah, AR_PHY_TEST, AR_PHY_TEST_RX_OBS_SEL_BIT5);
+	REG_RMW_FIELD(ah, AR_PHY_TEST_CTL_STATUS, AR_PHY_TEST_CTL_RX_OBS_SEL, 0);
+
+	memset(buf, 0, len);
+	for (i = 0; i < len; i++) {
+		for (j = 0; j < 4; j++) {
+			u32 regval = REG_READ(ah, AR_PHY_TST_ADC);
+
+			buf[i] <<= 2;
+			buf[i] |= (regval & 1) | ((regval & BIT(10)) >> 9);
+			udelay(1);
+		}
+	}
+}
+
 void ar9003_hw_attach_phy_ops(struct ath_hw *ah)
 {
 	struct ath_hw_private_ops *priv_ops = ath9k_hw_private_ops(ah);
@@ -1983,6 +2003,7 @@ void ar9003_hw_attach_phy_ops(struct ath
 	priv_ops->set_radar_params = ar9003_hw_set_radar_params;
 	priv_ops->fast_chan_change = ar9003_hw_fast_chan_change;
 
+	ops->get_adc_entropy = ar9003_hw_get_adc_entropy;
 	ops->antdiv_comb_conf_get = ar9003_hw_antdiv_comb_conf_get;
 	ops->antdiv_comb_conf_set = ar9003_hw_antdiv_comb_conf_set;
 	ops->spectral_scan_config = ar9003_hw_spectral_scan_config;
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -765,7 +765,8 @@ static void ath9k_init_txpower_limits(st
 	if (ah->caps.hw_caps & ATH9K_HW_CAP_5GHZ)
 		ath9k_init_band_txpower(sc, NL80211_BAND_5GHZ);
 
-	ah->curchan = curchan;
+	if (curchan)
+		ah->curchan = curchan;
 }
 
 static const struct ieee80211_iface_limit if_limits[] = {
@@ -958,6 +959,18 @@ static void ath9k_set_hw_capab(struct at
 	SET_IEEE80211_PERM_ADDR(hw, common->macaddr);
 }
 
+static void ath_get_initial_entropy(struct ath_softc *sc)
+{
+	struct ath_hw *ah = sc->sc_ah;
+	char buf[256];
+
+	/* reuse last channel initialized by the tx power test */
+	ath9k_hw_reset(ah, ah->curchan, NULL, false);
+
+	ath9k_hw_get_adc_entropy(ah, buf, sizeof(buf));
+	add_device_randomness(buf, sizeof(buf));
+}
+
 int ath9k_init_device(u16 devid, struct ath_softc *sc,
 		    const struct ath_bus_ops *bus_ops)
 {
@@ -1003,6 +1016,8 @@ int ath9k_init_device(u16 devid, struct
 		ARRAY_SIZE(ath9k_tpt_blink));
 #endif
 
+	ath_get_initial_entropy(sc);
+
 	/* Register with mac80211 */
 	error = ieee80211_register_hw(hw);
 	if (error)
--- a/drivers/net/wireless/ath/ath9k/hw-ops.h
+++ b/drivers/net/wireless/ath/ath9k/hw-ops.h
@@ -100,6 +100,12 @@ static inline void ath9k_hw_tx99_set_txp
 		ath9k_hw_ops(ah)->tx99_set_txpower(ah, power);
 }
 
+static inline void ath9k_hw_get_adc_entropy(struct ath_hw *ah,
+		u8 *buf, size_t len)
+{
+	ath9k_hw_ops(ah)->get_adc_entropy(ah, buf, len);
+}
+
 #ifdef CPTCFG_ATH9K_BTCOEX_SUPPORT
 
 static inline void ath9k_hw_set_bt_ant_diversity(struct ath_hw *ah, bool enable)
--- a/drivers/net/wireless/ath/ath9k/ar5008_phy.c
+++ b/drivers/net/wireless/ath/ath9k/ar5008_phy.c
@@ -1322,9 +1322,30 @@ void ar5008_hw_init_rate_txpower(struct
 	}
 }
 
+static void ar5008_hw_get_adc_entropy(struct ath_hw *ah, u8 *buf, size_t len)
+{
+	int i, j;
+
+	REG_RMW_FIELD(ah, AR_PHY_TEST, AR_PHY_TEST_BBB_OBS_SEL, 1);
+	REG_CLR_BIT(ah, AR_PHY_TEST, AR_PHY_TEST_RX_OBS_SEL_BIT5);
+	REG_RMW_FIELD(ah, AR_PHY_TEST2, AR_PHY_TEST2_RX_OBS_SEL, 0);
+
+	memset(buf, 0, len);
+	for (i = 0; i < len; i++) {
+		for (j = 0; j < 4; j++) {
+			u32 regval = REG_READ(ah, AR_PHY_TST_ADC);
+
+			buf[i] <<= 2;
+			buf[i] |= (regval & 1) | ((regval & BIT(9)) >> 8);
+			udelay(1);
+		}
+	}
+}
+
 int ar5008_hw_attach_phy_ops(struct ath_hw *ah)
 {
 	struct ath_hw_private_ops *priv_ops = ath9k_hw_private_ops(ah);
+	struct ath_hw_ops *ops = ath9k_hw_ops(ah);
 	static const u32 ar5416_cca_regs[6] = {
 		AR_PHY_CCA,
 		AR_PHY_CH1_CCA,
@@ -1339,6 +1360,8 @@ int ar5008_hw_attach_phy_ops(struct ath_
 	if (ret)
 	    return ret;
 
+	ops->get_adc_entropy = ar5008_hw_get_adc_entropy;
+
 	priv_ops->rf_set_freq = ar5008_hw_set_channel;
 	priv_ops->spur_mitigate_freq = ar5008_hw_spur_mitigate;
 
--- a/drivers/net/wireless/ath/ath9k/ar9002_phy.h
+++ b/drivers/net/wireless/ath/ath9k/ar9002_phy.h
@@ -20,6 +20,12 @@
 #define PHY_AGC_CLR             0x10000000
 #define RFSILENT_BB             0x00002000
 
+#define AR_PHY_TEST_BBB_OBS_SEL       0x780000
+#define AR_PHY_TEST_BBB_OBS_SEL_S     19
+
+#define AR_PHY_TEST_RX_OBS_SEL_BIT5_S 23
+#define AR_PHY_TEST_RX_OBS_SEL_BIT5   (1 << AR_PHY_TEST_RX_OBS_SEL_BIT5_S)
+
 #define AR_PHY_TURBO                0x9804
 #define AR_PHY_FC_TURBO_MODE        0x00000001
 #define AR_PHY_FC_TURBO_SHORT       0x00000002
@@ -36,6 +42,9 @@
 
 #define AR_PHY_TEST2			0x9808
 
+#define AR_PHY_TEST2_RX_OBS_SEL        0x3C00
+#define AR_PHY_TEST2_RX_OBS_SEL_S      10
+
 #define AR_PHY_TIMING2           0x9810
 #define AR_PHY_TIMING3           0x9814
 #define AR_PHY_TIMING3_DSC_MAN   0xFFFE0000
@@ -393,6 +402,8 @@
 #define AR_PHY_RFBUS_GRANT       0x9C20
 #define AR_PHY_RFBUS_GRANT_EN    0x00000001
 
+#define AR_PHY_TST_ADC      0x9C24
+
 #define AR_PHY_CHAN_INFO_GAIN_DIFF             0x9CF4
 #define AR_PHY_CHAN_INFO_GAIN_DIFF_UPPER_LIMIT 320
 
