From 96f25d50e2352922e16ae74bb16fd8b6985f0f66 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Wed, 30 Sep 2020 12:17:48 +0100
Subject: [PATCH] overlays: Add ghost-amp overlay

Add an overlay for the Ghost amplifier.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
 arch/arm/boot/dts/overlays/Makefile           |   1 +
 arch/arm/boot/dts/overlays/README             |   7 ++
 .../boot/dts/overlays/ghost-amp-overlay.dts   | 119 ++++++++++++++++++
 3 files changed, 127 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/ghost-amp-overlay.dts

--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -45,6 +45,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	exc3000.dtbo \
 	fe-pi-audio.dtbo \
 	fsm-demo.dtbo \
+	ghost-amp.dtbo \
 	goodix.dtbo \
 	googlevoicehat-soundcard.dtbo \
 	gpio-fan.dtbo \
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -775,6 +775,13 @@ Load:   dtoverlay=fsm-demo,<param>=<val>
 Params: fsm_debug               Enable debug logging (default off)
 
 
+Name:   ghost-amp
+Info:   An overlay for the Ghost amplifier.
+Load:   dtoverlay=ghost-amp,<param>=<val>
+Params: fsm_debug               Enable debug logging of the GPIO FSM (default
+                                off)
+
+
 Name:   goodix
 Info:   Enables I2C connected Goodix gt9271 multiple touch controller using
         GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/ghost-amp-overlay.dts
@@ -0,0 +1,119 @@
+// Overlay for the PCM5122-based Ghost amplifier using gpio-fsm
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio-fsm.h>
+
+#define ENABLE GF_SW(0)
+#define FAULT  GF_IP(0) // GPIO5
+#define RELAY1 GF_OP(0) // GPIO22
+#define RELAY2 GF_OP(1) // GPIO23
+
+/ {
+	compatible = "brcm,bcm2835";
+
+	fragment@0 {
+		target = <&i2s>;
+		__overlay__ {
+			status = "okay";
+		};
+	};
+
+	fragment@1 {
+		target = <&i2c1>;
+		__overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "okay";
+
+			pcm5122@4c {
+				#sound-dai-cells = <0>;
+				compatible = "ti,pcm5122";
+				reg = <0x4c>;
+				AVDD-supply = <&vdd_3v3_reg>;
+				DVDD-supply = <&vdd_3v3_reg>;
+				CPVDD-supply = <&vdd_3v3_reg>;
+				status = "okay";
+			};
+		};
+	};
+
+	fragment@2 {
+		target = <&sound>;
+		iqaudio_dac: __overlay__ {
+			compatible = "iqaudio,iqaudio-dac";
+			i2s-controller = <&i2s>;
+			mute-gpios = <&amp 0 0>;
+			iqaudio-dac,auto-mute-amp;
+			status = "okay";
+		};
+	};
+
+	fragment@3 {
+		target-path = "/";
+		__overlay__ {
+			amp: ghost-amp {
+				compatible = "rpi,gpio-fsm";
+
+				debug = <0>;
+				gpio-controller;
+				#gpio-cells = <2>;
+				num-soft-gpios = <1>;
+				gpio-line-names = "enable";
+				input-gpios  = <&gpio 5 1>;  // FAULT (active low)
+				output-gpios = <&gpio 22 0>, // RELAY1
+					       <&gpio 23 0>; // RELAY2
+				shutdown-timeout-ms = <1000>;
+
+				amp_off {
+					start_state;
+					shutdown_state;
+
+					set = <RELAY2 0>,
+					      <RELAY1 0>;
+					amp_on_1 = <ENABLE 1>;
+					fault = <FAULT 1>;
+				};
+
+				amp_on_1 {
+					set = <RELAY1 1>;
+					amp_on = <GF_DELAY 1500>;
+					amp_off = <ENABLE 0>;
+					fault = <FAULT 1>;
+				};
+
+				amp_on {
+					set = <RELAY2 1>;
+					amp_off_wait = <ENABLE 0>;
+					fault = <FAULT 1>;
+				};
+
+				amp_off_wait {
+					amp_off_1 = <GF_DELAY (30*60*1000)>,
+						    <GF_SHUTDOWN 0>;
+					amp_on = <ENABLE 1>;
+					fault = <FAULT 1>;
+				};
+
+				amp_off_1 {
+					set = <RELAY2 0>;
+					amp_on = <ENABLE 1>;
+					amp_off = <GF_DELAY 100>;
+					fault = <FAULT 1>;
+				};
+
+				// Keep this a distinct state to prevent
+				// changes and for the diagnostic output
+				fault {
+					set = <RELAY2 0>,
+					      <RELAY1 0>;
+					shutdown_state;
+				};
+			};
+		};
+	};
+
+	__overrides__ {
+		fsm_debug = <&amp>,"debug:0";
+	};
+};
