xref: /linux/Documentation/devicetree/bindings/tpm/tcg,tpm-tis-i2c.yaml (revision b19239143e393d4b52b3b9a17c7ac07138f2cfd4) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/tpm/tcg,tpm-tis-i2c.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: I²C-attached Trusted Platform Module conforming to TCG TIS specification
8
9maintainers:
10  - Lukas Wunner <lukas@wunner.de>
11
12description: |
13  The Trusted Computing Group (TCG) has defined a multi-vendor standard
14  for accessing a TPM chip.  It can be transported over various buses,
15  one of them being I²C.  The standard is named:
16  TCG PC Client Specific TPM Interface Specification (TIS)
17  https://trustedcomputinggroup.org/resource/pc-client-work-group-pc-client-specific-tpm-interface-specification-tis/
18
19  The I²C interface was not originally part of the standard, but added
20  in 2017 with a separate document:
21  TCG PC Client Platform TPM Profile Specification for TPM 2.0 (PTP)
22  https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
23
24  Recent TPM 2.0 chips conform to this generic interface, others use a
25  vendor-specific I²C interface.
26
27properties:
28  compatible:
29    oneOf:
30      - description: Generic TPM 2.0 chips conforming to TCG PTP interface
31        items:
32          - enum:
33              - infineon,slb9673
34              - nuvoton,npct75x
35              - st,st33ktpm2xi2c
36          - const: tcg,tpm-tis-i2c
37
38      - description: TPM 1.2 and 2.0 chips with vendor-specific I²C interface
39        items:
40          - enum:
41              - atmel,at97sc3204t # TPM 1.2
42              - infineon,slb9635tt # TPM 1.2 (maximum 100 kHz)
43              - infineon,slb9645tt # TPM 1.2 (maximum 400 kHz)
44              - infineon,tpm_i2c_infineon # TPM 1.2
45              - nuvoton,npct501 # TPM 1.2
46              - nuvoton,npct601 # TPM 2.0
47              - st,st33zp24-i2c # TPM 2.0
48              - winbond,wpct301 # TPM 1.2
49
50  reg:
51    description: address of TPM on the I²C bus
52
53allOf:
54  - $ref: tpm-common.yaml#
55
56required:
57  - compatible
58  - reg
59
60unevaluatedProperties: false
61
62examples:
63  - |
64    i2c {
65        #address-cells = <1>;
66        #size-cells = <0>;
67
68        tpm@57 {
69            label = "tpm";
70            compatible = "nuvoton,npct601";
71            reg = <0x57>;
72            linux,sml-base = <0x7f 0xfd450000>;
73            linux,sml-size = <0x10000>;
74        };
75    };
76
77  - |
78    #include <dt-bindings/gpio/gpio.h>
79    #include <dt-bindings/interrupt-controller/irq.h>
80    i2c {
81        #address-cells = <1>;
82        #size-cells = <0>;
83
84        tpm@13 {
85            reg = <0x13>;
86            compatible = "st,st33zp24-i2c";
87            interrupt-parent = <&gpio5>;
88            interrupts = <7 IRQ_TYPE_LEVEL_HIGH>;
89            lpcpd-gpios = <&gpio5 15 GPIO_ACTIVE_HIGH>;
90        };
91    };
92