xref: /linux/Documentation/devicetree/bindings/tpm/google,cr50.yaml (revision ae22a94997b8a03dcb3c922857c203246711f9d4) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/tpm/google,cr50.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Google Security Chip H1 (running Cr50 firmware)
8
9maintainers:
10  - Andrey Pronin <apronin@chromium.org>
11
12description: |
13  Google has designed a family of security chips called "Titan".
14  One member is the H1 built into Chromebooks and running Cr50 firmware:
15  https://www.osfc.io/2018/talks/google-secure-microcontroller-and-ccd-closed-case-debugging/
16
17  The chip provides several functions, including TPM 2.0 like functionality.
18  It communicates over SPI or I²C using the FIFO protocol described in the
19  TCG PC Client Platform TPM Profile Specification for TPM 2.0 (PTP), sec 6:
20  https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
21
22properties:
23  compatible:
24    const: google,cr50
25
26allOf:
27  - $ref: tpm-common.yaml#
28
29anyOf:
30  - $ref: /schemas/spi/spi-peripheral-props.yaml#
31  - $ref: tcg,tpm-tis-i2c.yaml#/properties/reg
32
33required:
34  - compatible
35  - reg
36
37unevaluatedProperties: false
38
39examples:
40  - |
41    spi {
42        #address-cells = <1>;
43        #size-cells = <0>;
44
45        tpm@0 {
46            reg = <0>;
47            compatible = "google,cr50";
48            spi-max-frequency = <800000>;
49        };
50    };
51
52  - |
53    #include <dt-bindings/interrupt-controller/irq.h>
54    i2c {
55        #address-cells = <1>;
56        #size-cells = <0>;
57
58        tpm@50 {
59            compatible = "google,cr50";
60            reg = <0x50>;
61            interrupts-extended = <&pio 88 IRQ_TYPE_EDGE_FALLING>;
62            pinctrl-names = "default";
63            pinctrl-0 = <&cr50_int>;
64        };
65    };
66