openwrt_lede/target/linux/brcm2708/patches-4.4/0570-BCM270X_DT-Add-spi0-cs-overlay.patch

From 1a2339385e478e3ae3ee4f79edbfefd7fd22e96c Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Mon, 16 Jan 2017 14:53:12 +0000
Subject: [PATCH] BCM270X_DT: Add spi0-cs overlay

The spi0-cs overlay allows the software chip selectts to be modified
using the cs0_pin and cs1_pin parameters.
---
 arch/arm/boot/dts/overlays/Makefile            |  1 +
 arch/arm/boot/dts/overlays/README              |  9 +++++++-
 arch/arm/boot/dts/overlays/spi0-cs-overlay.dts | 29 ++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/boot/dts/overlays/spi0-cs-overlay.dts

--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -93,6 +93,7 @@ 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-$(RPI_DT_OVERLAYS) += spi0-cs.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi0-hw-cs.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi1-1cs.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += spi1-2cs.dtbo
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -1131,7 +1131,7 @@ Params: <None>
 
 
 Name:   spi-gpio35-39
-Info:   move SPI function block to GPIO 35 to 39
+Info:   Move SPI function block to GPIO 35 to 39
 Load:   dtoverlay=spi-gpio35-39
 Params: <None>
 
@@ -1142,6 +1142,13 @@ Load:   dtoverlay=spi-rtc,<param>=<val>
 Params: pcf2123                 Select the PCF2123 device
 
 
+Name:   spi0-cs
+Info:   Allows the (software) CS pins for SPI0 to be changed
+Load:   dtoverlay=spi0-cs,<param>=<val>
+Params: cs0_pin                 GPIO pin for CS0 (default 8)
+        cs1_pin                 GPIO pin for CS1 (default 7)
+
+
 Name:   spi0-hw-cs
 Info:   Re-enables hardware CS/CE (chip selects) for SPI0
 Load:   dtoverlay=spi0-hw-cs
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/spi0-cs-overlay.dts
@@ -0,0 +1,29 @@
+/dts-v1/;
+/plugin/;
+
+
+/ {
+	compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";
+
+	fragment@0 {
+		target = <&spi0_cs_pins>;
+		frag0: __overlay__ {
+			brcm,pins = <8 7>;
+		};
+	};
+
+	fragment@1 {
+		target = <&spi0>;
+		frag1: __overlay__ {
+			cs-gpios = <&gpio 8 1>, <&gpio 7 1>;
+			status = "okay";
+		};
+	};
+
+	__overrides__ {
+		cs0_pin  = <&frag0>,"brcm,pins:0",
+			   <&frag1>,"cs-gpios:4";
+		cs1_pin  = <&frag0>,"brcm,pins:4",
+			   <&frag1>,"cs-gpios:16";
+	};
+};