ASoC: Only do WM8994 bias off transition from standby

Otherwise we may try to power down multiple times when the using
idle bias off and the driver is removed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/codecs/wm8994.c

@@ -3007,34 +3007,39 @@ static int wm8994_set_bias_level(struct snd_soc_codec *codec,
 		break;
 
 	case SND_SOC_BIAS_OFF:
-		/* Switch over to startup biases */
-		snd_soc_update_bits(codec, WM8994_ANTIPOP_2,
-				    WM8994_BIAS_SRC | WM8994_STARTUP_BIAS_ENA |
-				    WM8994_VMID_BUF_ENA |
-				    WM8994_VMID_RAMP_MASK,
-				    WM8994_BIAS_SRC | WM8994_STARTUP_BIAS_ENA |
-				    WM8994_VMID_BUF_ENA |
-				    (1 << WM8994_VMID_RAMP_SHIFT));
-
-		/* Disable main biases */
-		snd_soc_update_bits(codec, WM8994_POWER_MANAGEMENT_1,
-				    WM8994_BIAS_ENA | WM8994_VMID_SEL_MASK, 0);
+		if (codec->bias_level == SND_SOC_BIAS_STANDBY) {
+			/* Switch over to startup biases */
+			snd_soc_update_bits(codec, WM8994_ANTIPOP_2,
+					    WM8994_BIAS_SRC |
+					    WM8994_STARTUP_BIAS_ENA |
+					    WM8994_VMID_BUF_ENA |
+					    WM8994_VMID_RAMP_MASK,
+					    WM8994_BIAS_SRC |
+					    WM8994_STARTUP_BIAS_ENA |
+					    WM8994_VMID_BUF_ENA |
+					    (1 << WM8994_VMID_RAMP_SHIFT));
 
-		/* Discharge line */
-		snd_soc_update_bits(codec, WM8994_ANTIPOP_1,
-				    WM8994_LINEOUT1_DISCH |
-				    WM8994_LINEOUT2_DISCH,
-				    WM8994_LINEOUT1_DISCH |
-				    WM8994_LINEOUT2_DISCH);
+			/* Disable main biases */
+			snd_soc_update_bits(codec, WM8994_POWER_MANAGEMENT_1,
+					    WM8994_BIAS_ENA |
+					    WM8994_VMID_SEL_MASK, 0);
 
-		msleep(5);
+			/* Discharge line */
+			snd_soc_update_bits(codec, WM8994_ANTIPOP_1,
+					    WM8994_LINEOUT1_DISCH |
+					    WM8994_LINEOUT2_DISCH,
+					    WM8994_LINEOUT1_DISCH |
+					    WM8994_LINEOUT2_DISCH);
 
-		/* Switch off startup biases */
-		snd_soc_update_bits(codec, WM8994_ANTIPOP_2,
-				    WM8994_BIAS_SRC | WM8994_STARTUP_BIAS_ENA |
-				    WM8994_VMID_BUF_ENA |
-				    WM8994_VMID_RAMP_MASK, 0);
+			msleep(5);
 
+			/* Switch off startup biases */
+			snd_soc_update_bits(codec, WM8994_ANTIPOP_2,
+					    WM8994_BIAS_SRC |
+					    WM8994_STARTUP_BIAS_ENA |
+					    WM8994_VMID_BUF_ENA |
+					    WM8994_VMID_RAMP_MASK, 0);
+		}
 		break;
 	}
 	codec->bias_level = level;