[U-Boot] [PATCH 11/60] ARM: tegra: add DT alias for GPIO controller

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

Future Tegra chips contain multiple entirely separate GPIO controllers. It
is plausible that boards using those chips will end up with non-DT-driven
code that manipulates GPIOs, just like a few Tegra boards do today. In
that case, we'll want to make sure that the mapping from the global
integer GPIO numbering to GPIO controller occurs in a defined order, so
that the right GPIO is chosen in each case. To guarantee that order, GPIO
controllers must have specific DM "seq" values. This can be ensured via DT
aliases.

This is a no-op for current chips since there's only one GPIO controller.
However, it provides a good example for cargo-cult programming:-)

The aliases are added to the SoC DTSI files since there is no need for
them to vary between boards, and doing so avoids having to duplicate the
entry in each board's DT file. Any additional board-specific GPIO
controllers can be referenced by additional aliases (starting at 1) in
board DT files if needed.

Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
 arch/arm/dts/tegra114.dtsi | 4 ++++
 arch/arm/dts/tegra20.dtsi  | 4 ++++
 arch/arm/dts/tegra210.dtsi | 4 ++++
 arch/arm/dts/tegra30.dtsi  | 4 ++++
 4 files changed, 16 insertions(+)

diff --git a/arch/arm/dts/tegra114.dtsi b/arch/arm/dts/tegra114.dtsi
index 88bdc4904508..fd43cb1805aa 100644
--- a/arch/arm/dts/tegra114.dtsi
+++ b/arch/arm/dts/tegra114.dtsi
@@ -7,6 +7,10 @@
 / {
 	compatible = "nvidia,tegra114";
 
+	aliases {
+		gpio0 = "/gpio at 6000d000";
+	};
+
 	tegra_car: clock {
 		compatible = "nvidia,tegra114-car";
 		reg = <0x60006000 0x1000>;
diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi
index 31223e4fc9aa..fd1197e73d30 100644
--- a/arch/arm/dts/tegra20.dtsi
+++ b/arch/arm/dts/tegra20.dtsi
@@ -9,6 +9,10 @@
 	compatible = "nvidia,tegra20";
 	interrupt-parent = <&lic>;
 
+	aliases {
+		gpio0 = "/gpio at 6000d000";
+	};
+
 	host1x at 50000000 {
 		u-boot,dm-pre-reloc;
 		compatible = "nvidia,tegra20-host1x", "simple-bus";
diff --git a/arch/arm/dts/tegra210.dtsi b/arch/arm/dts/tegra210.dtsi
index fd4cc793d906..8f6a30851e21 100644
--- a/arch/arm/dts/tegra210.dtsi
+++ b/arch/arm/dts/tegra210.dtsi
@@ -12,6 +12,10 @@
 	#address-cells = <2>;
 	#size-cells = <2>;
 
+	aliases {
+		gpio0 = "/gpio at 6000d000";
+	};
+
 	pcie-controller at 01003000 {
 		compatible = "nvidia,tegra210-pcie";
 		device_type = "pci";
diff --git a/arch/arm/dts/tegra30.dtsi b/arch/arm/dts/tegra30.dtsi
index 5ea7e347f3fa..f6d4fd54d4f3 100644
--- a/arch/arm/dts/tegra30.dtsi
+++ b/arch/arm/dts/tegra30.dtsi
@@ -8,6 +8,10 @@
 	compatible = "nvidia,tegra30";
 	interrupt-parent = <&intc>;
 
+	aliases {
+		gpio0 = "/gpio at 6000d000";
+	};
+
 	intc: interrupt-controller at 50041000 {
 		compatible = "arm,cortex-a9-gic";
 		reg = <0x50041000 0x1000
-- 
2.8.1