Add support for audio playback via WCD937X/WSA881X. From DSP
and rxmacro the sound stream goes into AUX port of wcd codec.
wcd codec decodes digital audio into analog and outputs it to
single wsa amplifier hence only the mono configuration.

The audio playback is verified using the following commands:

amixer -c0 cset iface=MIXER,name='AUX_RDAC Switch' 1
amixer -c0 cset iface=MIXER,name='RX_RX2 Digital Volume' 80
amixer -c0 cset iface=MIXER,name='RX INT2_1 MIX1 INP0' 'RX2'
amixer -c0 cset iface=MIXER,name='RX_CODEC_DMA_RX_1 Audio Mixer MultiMedia1' 1
amixer -c0 cset iface=MIXER,name='RX_MACRO RX2 MUX' 'AIF2_PB'
amixer -c0 cset iface=MIXER,name='SpkrMono WSA_RDAC' 1
amixer -c0 cset iface=MIXER,name='LO Switch' 1

aplay -D hw:0,0 /usr/share/sounds/alsa/Front_Center.wav

Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
 arch/arm64/boot/dts/qcom/qrb4210-rb2.dts | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
index 76b9ae1b0ebc..b37b872f1a89 100644
--- a/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
+++ b/arch/arm64/boot/dts/qcom/qrb4210-rb2.dts
@@ -121,7 +121,9 @@ sound {
 		pinctrl-0 = <&lpi_i2s2_active>;
 		pinctrl-names = "default";
 		model = "Qualcomm-RB2-WSA8815-Speakers-DMIC0";
-		audio-routing = "MM_DL1", "MultiMedia1 Playback",
+		audio-routing = "IN3_AUX", "AUX_OUT",
+				"SpkrMono WSA_IN", "AUX",
+				"MM_DL1", "MultiMedia1 Playback",
 				"MM_DL2", "MultiMedia2 Playback";
 
 		mm1-dai-link {
@@ -163,6 +165,22 @@ codec {
 				sound-dai = <&lt9611_codec 0>;
 			};
 		};
+
+		wsa-dai-link {
+			link-name = "WSA Playback";
+
+			cpu {
+				sound-dai = <&q6afedai RX_CODEC_DMA_RX_1>;
+			};
+
+			platform {
+				sound-dai = <&q6routing>;
+			};
+
+			codec {
+				sound-dai = <&wsa881x>, <&wcd937x 0>, <&swr1 3>, <&rxmacro 1>;
+			};
+		};
 	};
 
 	wcd937x: codec {
-- 
2.45.2