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From 5962d99b5efed4297ed5c1807d21b406ab86aef1 Mon Sep 17 00:00:00 2001
From: wavelet2 <20504977+wavelet2@users.noreply.github.com>
Date: Mon, 15 Apr 2019 10:00:20 +0100
Subject: [PATCH] Maxim MAX98357A I2S DAC overlay (#2935)
Add overlay for Maxim MAX98357A I2S DAC.
Signed-off-by: Richard Steedman <richard.steedman@gmail.com>
---
arch/arm/boot/dts/overlays/Makefile | 1 +
arch/arm/boot/dts/overlays/README | 9 ++
.../boot/dts/overlays/max98357a-overlay.dts | 84 +++++++++++++++++++
3 files changed, 94 insertions(+)
create mode 100644 arch/arm/boot/dts/overlays/max98357a-overlay.dts
--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -75,6 +75,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
justboom-dac.dtbo \
justboom-digi.dtbo \
ltc294x.dtbo \
+ max98357a.dtbo \
mbed-dac.dtbo \
mcp23017.dtbo \
mcp23s17.dtbo \
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -1276,6 +1276,15 @@ Params: ltc2941 Select t
See the datasheet for more information.
+Name: max98357a
+Info: Configures the Maxim MAX98357A I2S DAC
+Load: dtoverlay=max98357a,<param>=<val>
+Params: no-sdmode Driver does not manage the state of the DAC's
+ SD_MODE pin (i.e. chip is always on).
+ sdmode-pin integer, GPIO pin connected to the SD_MODE input
+ of the DAC (default GPIO4 if parameter omitted).
+
+
Name: mbed-dac
Info: Configures the mbed AudioCODEC (TLV320AIC23B)
Load: dtoverlay=mbed-dac
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/max98357a-overlay.dts
@@ -0,0 +1,84 @@
+// Overlay for Maxim MAX98357A audio DAC
+
+// dtparams:
+// no-sdmode - SD_MODE pin not managed by driver.
+// sdmode-pin - Specify GPIO pin to which SD_MODE is connected (default 4).
+
+/dts-v1/;
+/plugin/;
+
+/ {
+ compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";
+
+ /* Enable I2S */
+ fragment@0 {
+ target = <&i2s>;
+ __overlay__ {
+ status = "okay";
+ };
+ };
+
+ /* DAC whose SD_MODE pin is managed by driver (via GPIO pin) */
+ fragment@1 {
+ target-path = "/";
+ __overlay__ {
+ max98357a_dac: max98357a {
+ compatible = "maxim,max98357a";
+ #sound-dai-cells = <0>;
+ sdmode-gpios = <&gpio 4 0>; /* 2nd word overwritten by sdmode-pin parameter */
+ status = "okay";
+ };
+ };
+ };
+
+ /* DAC whose SD_MODE pin is not managed by driver */
+ fragment@2 {
+ target-path = "/";
+ __dormant__ {
+ max98357a_nsd: max98357a {
+ compatible = "maxim,max98357a";
+ #sound-dai-cells = <0>;
+ status = "okay";
+ };
+ };
+ };
+
+ /* Soundcard connecting I2S to DAC with SD_MODE */
+ fragment@3 {
+ target = <&sound>;
+ __overlay__ {
+ compatible = "simple-audio-card";
+ simple-audio-card,format = "i2s";
+ simple-audio-card,name = "MAX98357A";
+ status = "okay";
+ simple-audio-card,cpu {
+ sound-dai = <&i2s>;
+ };
+ simple-audio-card,codec {
+ sound-dai = <&max98357a_dac>;
+ };
+ };
+ };
+
+ /* Soundcard connecting I2S to DAC without SD_MODE */
+ fragment@4 {
+ target = <&sound>;
+ __dormant__ {
+ compatible = "simple-audio-card";
+ simple-audio-card,format = "i2s";
+ simple-audio-card,name = "MAX98357A";
+ status = "okay";
+ simple-audio-card,cpu {
+ sound-dai = <&i2s>;
+ };
+ simple-audio-card,codec {
+ sound-dai = <&max98357a_nsd>;
+ };
+ };
+ };
+
+ __overrides__ {
+ no-sdmode = <0>,"-1+2-3+4";
+ sdmode-pin = <&max98357a_dac>,"sdmode-gpios:4";
+ };
+};
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