[[PATCH v2] tpm: Add wolfTPM library support for TPM 2.0 04/12] dts: add TPM device tree nodes for RPi4, QEMU, and sandbox

[David Garske]

From: Aidan <aidan at wolfssl.com>

Add device tree entries for TPM devices across three platforms:

bcm2711-rpi-4-b.dts:
  Add SPI0 node with Infineon SLB9670/9672 TPM on CE1 (GPIO7),
  matching the standard Linux tpm-slb9670 overlay. Add spi0 alias
  so wolfTPM finds the bus at index 0.

bcm2711-rpi-4-b-u-boot.dtsi (new file):
  Add soft-SPI (GPIO bit-bang) fallback node for TPM communication.
  This uses spi-gpio with GPIO11/10/9/7 and provides an alternative
  to the hardware SPI driver when pinctrl naming differs between
  U-Boot and Linux device trees.

qemu-arm64.dts:
  Add MMIO-based TPM TIS node at 0x0c000000 for QEMU virt machine
  with swtpm. This allows wolfTPM testing via QEMU without hardware.

sandbox.dtsi:
  Add sandbox TPM SPI device (sandbox,tpm-spi) on SPI bus CS1 with
  a phandle reference to a sandbox TPM SPI emulator node. This
  enables wolfTPM SPI HAL testing in the sandbox environment.

Signed-off-by: Aidan Garske <aidan at wolfssl.com>
---
 arch/arm/dts/bcm2711-rpi-4-b-u-boot.dtsi | 54 ++++++++++++++++++++++++
 arch/arm/dts/bcm2711-rpi-4-b.dts         | 20 +++++++++
 arch/arm/dts/qemu-arm64.dts              |  4 ++
 arch/sandbox/dts/sandbox.dtsi            | 11 +++++
 4 files changed, 89 insertions(+)
 create mode 100644 arch/arm/dts/bcm2711-rpi-4-b-u-boot.dtsi

diff --git a/arch/arm/dts/bcm2711-rpi-4-b-u-boot.dtsi b/arch/arm/dts/bcm2711-rpi-4-b-u-boot.dtsi
new file mode 100644
index 00000000000..c38276abee9
--- /dev/null
+++ b/arch/arm/dts/bcm2711-rpi-4-b-u-boot.dtsi
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * U-Boot specific additions for Raspberry Pi 4 Model B
+ *
+ * Adds soft SPI support for Infineon SLB9670/9672 TPM HAT
+ * connected to SPI0 CE1 (GPIO 7)
+ *
+ * Uses GPIO bit-banging instead of hardware SPI to avoid
+ * GPIO chip naming issues (pinctrl-bcm2835 vs pinctrl-bcm2711)
+ */
+
+#include "bcm283x-u-boot.dtsi"
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+	aliases {
+		spi0 = &soft_spi;
+	};
+
+	soft_spi: soft-spi {
+		compatible = "spi-gpio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		status = "okay";
+		bootph-all;
+
+		/*
+		 * GPIO pins for SPI0 on Raspberry Pi 4:
+		 * GPIO 11 = SCLK
+		 * GPIO 10 = MOSI
+		 * GPIO 9  = MISO
+		 * GPIO 7  = CE1 (chip select for TPM)
+		 */
+		gpio-sck = <&gpio 11 GPIO_ACTIVE_HIGH>;
+		gpio-mosi = <&gpio 10 GPIO_ACTIVE_HIGH>;
+		gpio-miso = <&gpio 9 GPIO_ACTIVE_HIGH>;
+		cs-gpios = <&gpio 7 GPIO_ACTIVE_LOW>;
+		num-chipselects = <1>;
+		spi-delay-us = <1>;
+
+		/* Infineon SLB9672 TPM on CS1 */
+		tpm at 0 {
+			compatible = "infineon,slb9672", "tcg,tpm-tis-spi";
+			reg = <0>;
+			spi-max-frequency = <10000000>;
+			status = "okay";
+			bootph-all;
+		};
+	};
+};
+
+&gpio {
+	bootph-all;
+};
diff --git a/arch/arm/dts/bcm2711-rpi-4-b.dts b/arch/arm/dts/bcm2711-rpi-4-b.dts
index 72ce80fbf26..a09276dc279 100644
--- a/arch/arm/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/dts/bcm2711-rpi-4-b.dts
@@ -8,6 +8,11 @@
 	compatible = "raspberrypi,4-model-b", "brcm,bcm2711";
 	model = "Raspberry Pi 4 Model B";
 
+	/* Alias hardware SPI as spi0 so wolfTPM finds it at bus 0 */
+	aliases {
+		spi0 = &spi;
+	};
+
 	chosen {
 		/* 8250 auxiliary UART instead of pl011 */
 		stdout-path = "serial1:115200n8";
@@ -54,6 +59,21 @@
 		enable-active-high;
 		gpio = <&expgpio 6 GPIO_ACTIVE_HIGH>;
 	};
+
+};
+
+/* Hardware SPI with TPM - matches Linux tpm-slb9670 overlay */
+&spi {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi0_gpio7>;
+
+	/* Infineon SLB9670/9672 TPM 2.0 on CE1 (GPIO7) */
+	tpm at 1 {
+		compatible = "infineon,slb9670", "tcg,tpm_tis-spi";
+		reg = <1>;  /* CE1 */
+		spi-max-frequency = <32000000>;
+	};
 };
 
 &ddc0 {
diff --git a/arch/arm/dts/qemu-arm64.dts b/arch/arm/dts/qemu-arm64.dts
index 95fcf53ed74..e74d036a532 100644
--- a/arch/arm/dts/qemu-arm64.dts
+++ b/arch/arm/dts/qemu-arm64.dts
@@ -12,4 +12,8 @@
 #endif
 
 / {
+	tpm at 0c000000 {
+		compatible = "tcg,tpm-tis-mmio";
+		reg = <0x0 0x0c000000 0x0 0x5000>;
+	};
 };
diff --git a/arch/sandbox/dts/sandbox.dtsi b/arch/sandbox/dts/sandbox.dtsi
index 02b03894eaf..2fdd7f0e942 100644
--- a/arch/sandbox/dts/sandbox.dtsi
+++ b/arch/sandbox/dts/sandbox.dtsi
@@ -286,6 +286,17 @@
 			spi-max-frequency = <40000000>;
 			sandbox,filename = "spi.bin";
 		};
+
+		tpm_spi: tpm at 1 {
+			reg = <1>;
+			compatible = "sandbox,tpm-spi";
+			spi-max-frequency = <10000000>;
+			sandbox,emul = <&tpm_spi_emul>;
+		};
+	};
+
+	tpm_spi_emul: tpm-spi-emul {
+		compatible = "sandbox,tpm-spi-emul";
 	};
 
 	spl-test {
-- 
2.43.0