Re: [RFC 0/3] Enable firmware-managed USB resources on Qcom targets
From: Sriram Dash
Date: Wed Mar 06 2024 - 11:01:09 EST
On 3/6/2024 12:34 PM, Krzysztof Kozlowski wrote:
On 05/03/2024 19:04, Sriram Dash wrote:
On 3/5/2024 10:42 PM, Krzysztof Kozlowski wrote:
On 05/03/2024 17:57, Sriram Dash wrote:
Some target systems allow multiple resources to be managed by firmware.
Which? Why this is so vague...
SA8775 will be using it as pilot. Will include the target name.
On these targets, tasks related to clocks, regulators, resets, and
interconnects can be delegated to the firmware, while the remaining
responsibilities are handled by Linux.
To support the management of partial resources in Linux and leave the rest
to firmware, multiple power domains are introduced. Each power domain can
manage one or more resources, depending on the specific use case.
These power domains handle SCMI calls to the firmware, enabling the
activation and deactivation of firmware-managed resources.
The driver is responsible for managing multiple power domains and
linking them to consumers as needed. Incase there is only single
power domain, it is considered to be a standard GDSC hooked on to
the qcom dt node which is read and assigned to device structure
(by genpd framework) before the driver probe even begins.
This will break the ABI. Sorry, come with an ABI stable solution.
The plan is to include multiple power-domains and fw-managed
property or similar in the device tree and fw-managed property
will be deciding if we need some resource management offloaded
to firmware. So, OS is always in control here. The decision
making will be done in the drivers. Also, there will be no
separate vendor hooks.
This does not answer ABI breakage. Also, I don't have a clue what are
"vendor hooks".
Apologies for the confusion, Krysztof.
The bindings will depict whether the compatible will use
clocks/ regulators, etc or not. Will take care in the
next version on top of the scmi based dt solution.
Best regards,
Krzysztof