arm64: dts: ti: am62x-sk: Add overlay for HDMI audio

Enable audio output over HDMI instead of the 3.5mm jack.

A FET switch (U65) on the EVM muxes serial audio lines coming from McASP
between the codec (tlv320aic3106) and the HDMI bridge (sii9022).

By default it uses the codec, but it can be toggled to use the HDMI
bridge by shorting a (J24) header on the board.

Signed-off-by: Jai Luthra <j-luthra@ti.com>
[a-bhatia1: Cosmetic changes]
Signed-off-by: Aradhya Bhatia <a-bhatia1@ti.com>
Link: https://lore.kernel.org/r/20230809084559.17322-5-a-bhatia1@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>

Author: jailuthra

arch/arm64/boot/dts/ti/Makefile

@@ -19,6 +19,7 @@ dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-wifi-dahlia.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-wifi-dev.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am625-verdin-wifi-yavia.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am62-lp-sk.dtb
+dtb-$(CONFIG_ARCH_K3) += k3-am62x-sk-hdmi-audio.dtbo
 
 # Boards with AM62Ax SoC
 dtb-$(CONFIG_ARCH_K3) += k3-am62a7-sk.dtb
@@ -68,6 +69,8 @@ dtb-$(CONFIG_ARCH_K3) += k3-am69-sk.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-j784s4-evm.dtb
 
 # Enable support for device-tree overlays
+DTC_FLAGS_k3-am625-sk += -@
+DTC_FLAGS_k3-am62-lp-sk += -@
 DTC_FLAGS_k3-am6548-iot2050-advanced-m2 += -@
 DTC_FLAGS_k3-j721e-common-proc-board += -@
 DTC_FLAGS_k3-j721s2-common-proc-board += -@

arch/arm64/boot/dts/ti/k3-am62x-sk-hdmi-audio.dtso

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Audio playback via HDMI for AM625-SK and AM62-LP SK.
+ *
+ * Links:
+ * AM625 SK: https://www.ti.com/tool/SK-AM62
+ * AM62-LP SK: https://www.ti.com/tool/SK-AM62-LP
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+/dts-v1/;
+/plugin/;
+
+&{/} {
+	hdmi_audio: sound-sii9022 {
+		compatible = "simple-audio-card";
+		simple-audio-card,name = "AM62x-Sil9022-HDMI";
+		simple-audio-card,format = "i2s";
+		simple-audio-card,bitclock-master = <&hdmi_dailink_master>;
+		simple-audio-card,frame-master = <&hdmi_dailink_master>;
+
+		hdmi_dailink_master: simple-audio-card,cpu {
+			sound-dai = <&mcasp1>;
+			system-clock-direction-out;
+		};
+
+		simple-audio-card,codec {
+			sound-dai = <&sii9022>;
+		};
+	};
+};
+
+&mcasp1 {
+	auxclk-fs-ratio = <2177>;
+};
+
+&codec_audio {
+	status = "disabled";
+};