openwrt/target/linux/brcm2708/patches-4.4/0318-BCM270X_DT-i2c0-bcm2708-pin-group-params.patch

From 9b6cc71b7159bebe78cd1ee823a479c0ca485c82 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Fri, 6 May 2016 12:53:16 +0100
Subject: [PATCH] BCM270X_DT: i2c0-bcm2708 - pin group params

Add parameters to set pin groups as a unit, setting the pin function
appropriately. The parameters are:
  pins_0_1
  pins_28_29
  pins_44_45
  pins_46_47

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
 arch/arm/boot/dts/overlays/README                  | 11 ++++--
 .../arm/boot/dts/overlays/i2c0-bcm2708-overlay.dts | 43 +++++++++++++++++-----
 2 files changed, 42 insertions(+), 12 deletions(-)

--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -449,10 +449,15 @@ Params: ds1307                  Select t
 
 
 Name:   i2c0-bcm2708
-Info:   Enable the i2c_bcm2708 driver for the i2c0 bus
+Info:   Enable the i2c_bcm2708 driver for the i2c0 bus. Not all pin combinations
+        are usable on all platforms.
 Load:   dtoverlay=i2c0-bcm2708,<param>=<val>
-Params: sda0_pin                GPIO pin for SDA0 (0, 28 [or 44] - default 0)
-        scl0_pin                GPIO pin for SCL0 (1, 29 [or 45] - default 1)
+Params: sda0_pin                GPIO pin for SDA0 (deprecated - use pins_*)
+        scl0_pin                GPIO pin for SCL0 (deprecated - use pins_*)
+        pins_0_1                Use pins 0 and 1 (default)
+        pins_28_29              Use pins 28 and 29
+        pins_44_45              Use pins 44 and 45
+        pins_46_47              Use pins 46 and 47
 
 
 Name:   i2c1-bcm2708
--- a/arch/arm/boot/dts/overlays/i2c0-bcm2708-overlay.dts
+++ b/arch/arm/boot/dts/overlays/i2c0-bcm2708-overlay.dts
@@ -14,23 +14,48 @@
    fragment@0 {
       target = <&i2c0>;
       __overlay__ {
-         pinctrl-0 = <&i2c0_pins>;
          status = "okay";
       };
    };
 
    fragment@1 {
-      target = <&gpio>;
-      __overlay__ {
-         i2c0_pins: i2c0 {
-            brcm,pins = <0 1>;
-            brcm,function = <4>; /* alt0 */
-         };
+      target = <&i2c0_pins>;
+      frag1: __overlay__ {
+         brcm,pins = <0 1>;
+         brcm,function = <4>; /* alt0 */
+      };
+   };
+
+   fragment@2 {
+      target = <&i2c0_pins>;
+      __dormant__ {
+         brcm,pins = <28 29>;
+         brcm,function = <4>; /* alt0 */
+      };
+   };
+
+   fragment@3 {
+      target = <&i2c0_pins>;
+      __dormant__ {
+         brcm,pins = <44 45>;
+         brcm,function = <5>; /* alt1 */
+      };
+   };
+
+   fragment@4 {
+      target = <&i2c0_pins>;
+      __dormant__ {
+         brcm,pins = <46 47>;
+         brcm,function = <4>; /* alt0 */
       };
    };
 
    __overrides__ {
-      sda0_pin = <&i2c0_pins>,"brcm,pins:0";
-      scl0_pin = <&i2c0_pins>,"brcm,pins:4";
+      sda0_pin = <&frag1>,"brcm,pins:0";
+      scl0_pin = <&frag1>,"brcm,pins:4";
+      pins_0_1   = <0>,"+1-2-3-4";
+      pins_28_29 = <0>,"-1+2-3-4";
+      pins_44_45 = <0>,"-1-2+3-4";
+      pins_46_47 = <0>,"-1-2-3+4";
    };
 };