From 314347ab28a26ed9cc05777b74f6054a4d6db458 Mon Sep 17 00:00:00 2001
From: Thomas Kriechbaumer <thomas@kriechbaumer.name>
Date: Fri, 10 Jun 2016 20:07:01 +0200
Subject: [PATCH] add SPI RTC overlay

This currently supports PCF2123 chips on SPI0.0
---
 arch/arm/boot/dts/overlays/Makefile    |  1 +
 arch/arm/boot/dts/overlays/README      |  4 ++++
 arch/arm/boot/dts/overlays/spi-rtc.dts | 31 ++++++++++++++++++++++++++
 3 files changed, 36 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/spi-rtc.dts

diff --git a/arch/arm/boot/dts/overlays/Makefile b/arch/arm/boot/dts/overlays/Makefile
index e17bea26c888d8..f528bd4a33ca33 100644
--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -78,6 +78,7 @@ dtbo-$(RPI_DT_OVERLAYS) += smi.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += smi-dev.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += smi-nand.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi-gpio35-39.dtbo
+dtbo-$(RPI_DT_OVERLAYS) += spi-rtc.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi1-1cs.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi1-2cs.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi1-3cs.dtbo
diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
index dcb6849b0bc0ca..70e755ea8e7798 100644
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -974,6 +974,10 @@ Info:   move SPI function block to GPIO 35 to 39
 Load:   dtoverlay=spi-gpio35-39
 Params: <None>
 
+Name:   spi-rtc
+Info:   Adds support for a number of SPI Real Time Clock devices
+Load:   dtoverlay=spi-rtc,<param>=<val>
+Params: pcf2123                 Select the PCF2123 device
 
 Name:   spi1-1cs
 Info:   Enables spi1 with a single chip select (CS) line and associated spidev
diff --git a/arch/arm/boot/dts/overlays/spi-rtc.dts b/arch/arm/boot/dts/overlays/spi-rtc.dts
new file mode 100644
index 00000000000000..c65c17b9cce9b5
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/spi-rtc.dts
@@ -0,0 +1,31 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+  compatible = "brcm,bcm2708";
+
+  fragment@0 {
+    target = <&spidev0>;
+    __dormant__ {
+      status = "disabled";
+    };
+  };
+
+  fragment@1 {
+    target = <&spi0>;
+    __dormant__ {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      rtc-pcf2123@0 {
+        compatible = "nxp,rtc-pcf2123";
+        spi-max-frequency = <5000000>;
+        spi-cs-high = <1>;
+        reg = <0>;
+      };
+    };
+  };
+
+  __overrides__ {
+    pcf2123 = <0>, "=0=1";
+  };
+};