Re: [PATCH v13 5/6] i2c: tegra: Add support for SW mutex register

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

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On Tue, Nov 18, 2025 at 07:36:19PM +0530, Akhil R wrote:
> From: Kartik Rajput <kkartik@nvidia.com>
> 
> Add support for SW mutex register introduced in Tegra264 to provide
> an option to share the interface between multiple firmwares and/or
> VMs. This involves following steps:
> 
>  - A firmware/OS writes its unique ID to the mutex REQUEST field.
>  - Ownership is established when reading the GRANT field returns the
>    same ID.
>  - If GRANT shows a different non-zero ID, the firmware/OS retries
>    until timeout.
>  - After completing access, it releases the mutex by writing 0.
> 
> However, the hardware does not ensure any protection based on the
> values. The driver/firmware should honor the peer who already holds
> the mutex.
> 
> Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
> Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
> Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
> Acked-by: Thierry Reding <treding@nvidia.com>

Applied to for-next, thanks!


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