xref: /linux/Documentation/devicetree/bindings/tpm/tcg,tpm-tis-i2c.yaml (revision a23e1966932464e1c5226cb9ac4ce1d5fc10ba22) 
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          - const: tcg,tpm-tis-i2c
36
37      - description: TPM 1.2 and 2.0 chips with vendor-specific I²C interface
38        items:
39          - enum:
40              - atmel,at97sc3204t # TPM 1.2
41              - infineon,slb9635tt # TPM 1.2 (maximum 100 kHz)
42              - infineon,slb9645tt # TPM 1.2 (maximum 400 kHz)
43              - infineon,tpm_i2c_infineon # TPM 1.2
44              - nuvoton,npct501 # TPM 1.2
45              - nuvoton,npct601 # TPM 2.0
46              - st,st33zp24-i2c # TPM 2.0
47              - winbond,wpct301 # TPM 1.2
48
49  reg:
50    description: address of TPM on the I²C bus
51
52allOf:
53  - $ref: tpm-common.yaml#
54
55required:
56  - compatible
57  - reg
58
59unevaluatedProperties: false
60
61examples:
62  - |
63    i2c {
64        #address-cells = <1>;
65        #size-cells = <0>;
66
67        tpm@57 {
68            label = "tpm";
69            compatible = "nuvoton,npct601";
70            reg = <0x57>;
71            linux,sml-base = <0x7f 0xfd450000>;
72            linux,sml-size = <0x10000>;
73        };
74    };
75
76  - |
77    #include <dt-bindings/gpio/gpio.h>
78    #include <dt-bindings/interrupt-controller/irq.h>
79    i2c {
80        #address-cells = <1>;
81        #size-cells = <0>;
82
83        tpm@13 {
84            reg = <0x13>;
85            compatible = "st,st33zp24-i2c";
86            interrupt-parent = <&gpio5>;
87            interrupts = <7 IRQ_TYPE_LEVEL_HIGH>;
88            lpcpd-gpios = <&gpio5 15 GPIO_ACTIVE_HIGH>;
89        };
90    };
91