C6 deep sleep driver MVP

[bugadani]

cc #375

This PR aims to implement deep sleep support for the HP core of ESP32-C6. This is a more-or-less direct port of esp-idf (v5.1.2).

We deviate from the esp-idf implementation where it doesn't fit into our current architecture:

• we create a default sleep configuration structure first, that we then manipulate
• we apply hardware changes based on the completed sleep configuration structure
• then we enter and maybe exit sleep similar to esp-idf

The difference is, that in our case, the configured wakeup sources modify the sleep config directly, instead of an after-the-fact setup down the line. This, in theory, enables us to simplify the config structure from its current "in-memory register block" representation. This is not done for the sake of reducing porting effort.

Only LP_IO is implemented as a wakeup source, and probably only deep sleep works.

Status:

• startup code
• default sleep config
• deep sleep config
• wakeup sources - LP_IO only for now

Must

• The code compiles without errors or warnings.
• All examples work.
• cargo fmt was run.
• Your changes were added to the CHANGELOG.md in the proper section.
• You updated existing examples or added examples (if applicable).
• Added examples are checked in CI

Nice to have

• You add a description of your work to this PR.
• You added proper docs for your newly added features and code.

[bugadani]

I would appreciate if someone could help me test if the current state boots and doesn't break peripherals and radio, otherwise I'll carry on and test it myself when I have my new hardware built next week or after that.

[bjoernQ]

Tested this with a couple of examples in esp-hal - still works.
Tested with esp-wifi - still works.

[jessebraham]

Just checking in here, was this ready for review or are there still remaining tasks to resolve?

[bugadani]

I'm trying to progress with my project to a point where I can start testing this.

[bugadani]

Device now seems to be entering sleep, but can't yet wake up on GPIO level change.

[bugadani]

030a38e - wakeup has been achieved

[JurajSadel]

LGTM, thank you for working on this! The example works fine for me, I left just 2 nitpicks.

[t-moe]

I'm not sure how much work this is, but I could really use Timer wakeup apart from the GPIO....

[bugadani]

I'm not sure how much work this is

After wasting three weeks on this I decided to draw the line at the bare minimum I personally needed. I'm not sure how much work it is, depends on whether it's implemented in esp-idf (probably not extreme amounts of work) or not (low power systems aren't documented currently so it may not even be possible right now).

At any rate, this PR is big enough as it is, I'm kinda burnt out on this and timer support should be mostly additive on top of this.

[jessebraham]

Thanks for all your work on this!