Re: [PATCH v1 10/15] arm64: dts: imx8mn-var-som-symphony: Add TPM2 support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Incomplete hardware initialization for the TPM device due to missing `reset-gpios` driver handling.
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Note: The format of this review is altered and does not include direct quotes 
of the patch code due to recitation restrictions. I am providing a free-form 
summary of the review findings instead.

commit 752fc746ff7ba94f6473f1446bfe64ae3aa4003c
Author: Stefano Radaelli <stefano.r@variscite.com>
Subject: arm64: dts: imx8mn-var-som-symphony: Add TPM2 support

This commit adds support for the ST33K TPM2 device on the VAR-SOM Symphony 
carrier board. It introduces device tree nodes for the ST33K TPM2 connected 
over I2C and a PCA6408 GPIO expander intended to control the TPM reset signal.

[Severity: Medium]
In the newly added st33ktpm2xi2c node, there is a reset-gpios property
referencing pin 4 of the pca6408 GPIO expander. Will this actually bring
the TPM out of reset during boot?

Looking at the tpm_tis_i2c driver, it does not appear to contain code to
request and drive the reset-gpios property.

Furthermore, the pca6408 node does not declare a gpio-hog to statically
configure the pin state. This implies the GPIO expander pin will default to a
high-impedance input when the kernel boots.

Unless the board has a hardware pull-up resistor or the bootloader
specifically configures this pin as an active output before handing off to
Linux, won't the TPM remain held in reset and fail to probe?

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Sashiko AI review · https://sashiko.dev/#/patchset/cover.1783067947.git.stefano.r@variscite.com?part=10