| Tom Rini | 93743d2 | 2024-04-01 09:08:13 -0400 | [diff] [blame] | 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 | |
| 7 | title: Google Security Chip H1 (running Cr50 firmware) |
| 8 | |
| 9 | maintainers: |
| 10 | - Andrey Pronin <apronin@chromium.org> |
| 11 | |
| 12 | description: | |
| 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 | |
| 22 | properties: |
| 23 | compatible: |
| 24 | const: google,cr50 |
| 25 | |
| 26 | allOf: |
| 27 | - $ref: tpm-common.yaml# |
| 28 | |
| 29 | anyOf: |
| 30 | - $ref: /schemas/spi/spi-peripheral-props.yaml# |
| 31 | - $ref: tcg,tpm-tis-i2c.yaml#/properties/reg |
| 32 | |
| 33 | required: |
| 34 | - compatible |
| 35 | - reg |
| 36 | |
| 37 | unevaluatedProperties: false |
| 38 | |
| 39 | examples: |
| 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 | }; |