[PATCH 1/1] Add overlay for SLB9760 Iridium /LetsTrust TPM

[Alex Murray]

From: Peter Huewe <peterhuewe at gmx.de>

BugLink: https://bugs.launchpad.net/bugs/1822036

Device Tree overlay for the Infineon SLB9670 Trusted Platform Module add-on
boards, which can be used as a secure key storage and hwrng.
available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by
pi3g.

Signed-off-by: Peter Huewe <peterhuewe at gmx.de>
(cherry picked from commit c28ac2dc08bd73963f953a757a3362c64b5524ed
https://github.com/raspberrypi/linux rpi-4.14.y)
Signed-off-by: Alex Murray <alex.murray at canonical.com>
---
 arch/arm/boot/dts/overlays/Makefile           |  1 +
 arch/arm/boot/dts/overlays/README             |  8 ++++
 .../boot/dts/overlays/tpm-slb9670-overlay.dts | 44 +++++++++++++++++++
 3 files changed, 53 insertions(+)
 create mode 100644 arch/arm/boot/dts/overlays/tpm-slb9670-overlay.dts

diff --git a/arch/arm/boot/dts/overlays/Makefile b/arch/arm/boot/dts/overlays/Makefile
index 5439afd9b28c..ea7b14b8a10d 100644
--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -123,6 +123,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	superaudioboard.dtbo \
 	sx150x.dtbo \
 	tinylcd35.dtbo \
+	tpm-slb9670.dtbo \
 	uart0.dtbo \
 	uart1.dtbo \
 	upstream.dtbo \
diff --git a/arch/arm/boot/dts/overlays/README b/arch/arm/boot/dts/overlays/README
index 7ec84713cd06..96022feff661 100644
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -1762,6 +1762,14 @@ Params: speed                   Display SPI bus speed
                 dtoverlay=tinylcd35,touch,touchgpio=3
 
 
+Name:   tpm-slb9670
+Info:   Enables support for Infineon SLB9670 Trusted Platform Module add-on
+        boards, which can be used as a secure key storage and hwrng,
+        available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
+Load:   dtoverlay=tpm-slb9670
+Params: <None>
+
+
 Name:   uart0
 Info:   Change the pin usage of uart0
 Load:   dtoverlay=uart0,<param>=<val>
diff --git a/arch/arm/boot/dts/overlays/tpm-slb9670-overlay.dts b/arch/arm/boot/dts/overlays/tpm-slb9670-overlay.dts
new file mode 100644
index 000000000000..eac4511050de
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/tpm-slb9670-overlay.dts
@@ -0,0 +1,44 @@
+/*
+ * Device Tree overlay for the Infineon SLB9670 Trusted Platform Module add-on
+ * boards, which can be used as a secure key storage and hwrng.
+ * available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+	compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";
+
+	fragment at 0 {
+		target = <&spi0>;
+		__overlay__ {
+			status = "okay";
+		};
+	};
+
+	fragment at 1 {
+		target = <&spidev1>;
+		__overlay__ {
+			status = "disabled";
+		};
+	};
+
+	fragment at 2 {
+		target = <&spi0>;
+		__overlay__ {
+			/* needed to avoid dtc warning */
+			#address-cells = <1>;
+			#size-cells = <0>;
+			slb9670: slb9670 at 1 {
+				compatible = "infineon,slb9670";
+				reg = <1>;	/* CE1 */
+				#address-cells = <1>;
+				#size-cells = <0>;
+				spi-max-frequency = <32000000>;
+				status = "okay";
+			};
+
+		};
+	};
+};
-- 
2.17.1