The NVIDIA Tegra186 SoC has a Tachometer Controller that analyzes the
PWM signal of a Fan and reports the period value through pwm interface.

Signed-off-by: Rajkumar Rampelli <rrajk@nvidia.com>
---

V2: Renamed clock-names/reset-names dt properties values to "tachometer"
    Renamed compatible property value to "nvidia-tegra186-pwm-tachometer"

 arch/arm64/boot/dts/nvidia/tegra186-p2771-0000.dts |  5 +++++
 arch/arm64/boot/dts/nvidia/tegra186.dtsi           | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/arm64/boot/dts/nvidia/tegra186-p2771-0000.dts b/arch/arm64/boot/dts/nvidia/tegra186-p2771-0000.dts
index bd5305a..13c3e59 100644
--- a/arch/arm64/boot/dts/nvidia/tegra186-p2771-0000.dts
+++ b/arch/arm64/boot/dts/nvidia/tegra186-p2771-0000.dts
@@ -172,4 +172,9 @@
 			vin-supply = <&vdd_5v0_sys>;
 		};
 	};
+
+	tachometer@39c0000 {
+		nvidia,pulse-per-rev = <2>;
+		nvidia,capture-window-len = <2>;
+	};
 };
diff --git a/arch/arm64/boot/dts/nvidia/tegra186.dtsi b/arch/arm64/boot/dts/nvidia/tegra186.dtsi
index 731cd01..19e1afc 100644
--- a/arch/arm64/boot/dts/nvidia/tegra186.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra186.dtsi
@@ -1042,4 +1042,15 @@
 		reset-names = "pwm";
 		status = "disabled";
 	};
+
+	tegra_tachometer: tachometer@39c0000 {
+		compatible = "nvidia,tegra186-pwm-tachometer";
+		reg = <0x0 0x039c0000 0x0 0x10>;
+		#pwm-cells = <2>;
+		clocks = <&bpmp TEGRA186_CLK_TACH>;
+		clock-names = "tachometer";
+		resets = <&bpmp TEGRA186_RESET_TACH>;
+		reset-names = "tachometer";
+		status = "disabled";
+	};
 };
-- 
2.1.4