openwrt_lede/target/linux/brcm2708/patches-4.4/0418-dts-Add-overlay-for-NXP-SC16IS752-Dual-UART-with-SPI.patch

From 2770e16422c3d3df76bb510a309877b507d4553f Mon Sep 17 00:00:00 2001
From: Erdem MEYDANLI <erdem.meydanli@punica.com.tr>
Date: Thu, 30 Jun 2016 21:05:08 +0300
Subject: [PATCH] dts: Add overlay for NXP SC16IS752 Dual UART with SPI
 Interface

---
 arch/arm/boot/dts/overlays/Makefile                |  1 +
 arch/arm/boot/dts/overlays/README                  | 10 ++++
 .../boot/dts/overlays/sc16is752-spi1-overlay.dts   | 61 ++++++++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/sc16is752-spi1-overlay.dts

--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -71,6 +71,7 @@ dtbo-$(RPI_DT_OVERLAYS) += rpi-ft5406.dt
 dtbo-$(RPI_DT_OVERLAYS) += rpi-proto.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += rpi-sense.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += rra-digidac1-wm8741-audio.dtbo
+dtbo-$(RPI_DT_OVERLAYS) += sc16is752-spi1.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += sdhost.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += sdio.dtbo
 dtbo-$(RPI_DT_OVERLAYS) += sdio-1bit.dtbo
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -888,6 +888,16 @@ Load:   dtoverlay=rra-digidac1-wm8741-au
 Params: <None>
 
 
+Name:   sc16is752-spi1
+Info:   Overlay for the NXP SC16IS752 Dual UART with SPI Interface
+        Enables the chip on SPI1.
+        N.B.: spi1 is only accessible on devices with a 40pin header, eg:
+              A+, B+, Zero and PI2 B; as well as the Compute Module.
+
+Load:   dtoverlay=sc16is752-spi1,<param>=<val>
+Params: int_pin                 GPIO used for IRQ (default 24)
+
+
 Name:   sdhost
 Info:   Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
         N.B. This overlay is designed for situations where the mmc driver is
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/sc16is752-spi1-overlay.dts
@@ -0,0 +1,61 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+	compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";
+
+	fragment@0 {
+		target = <&gpio>;
+		__overlay__ {
+			spi1_pins: spi1_pins {
+				brcm,pins = <19 20 21>;
+				brcm,function = <3>; /* alt4 */
+			};
+
+			spi1_cs_pins: spi1_cs_pins {
+				brcm,pins = <18>;
+				brcm,function = <1>; /* output */
+			};
+		};
+	};
+
+	fragment@1 {
+		target = <&spi1>;
+		frag1: __overlay__ {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&spi1_pins &spi1_cs_pins>;
+			cs-gpios = <&gpio 18 1>;
+			status = "okay";
+
+			sc16is752: sc16is752@0 {
+				compatible = "nxp,sc16is752";
+				reg = <0>; /* CE0 */
+				clocks = <&sc16is752_clk>;
+				interrupt-parent = <&gpio>;
+				interrupts = <24 2>; /* IRQ_TYPE_EDGE_FALLING */
+				#gpio-controller;
+				#gpio-cells = <2>;
+				spi-max-frequency = <4000000>;
+
+				sc16is752_clk: sc16is752_clk {
+					compatible = "fixed-clock";
+					#clock-cells = <0>;
+					clock-frequency = <14745600>;
+				};
+			};
+		};
+	};
+
+	fragment@2 {
+		target = <&aux>;
+		__overlay__ {
+			status = "okay";
+		};
+	};
+
+    __overrides__ {
+      int_pin = <&sc16is752>,"interrupts:0";
+    };
+};