Async WiFi: connect/disconnect/scan/wait_for_event

[MabezDev]

First off, I'm sorry. This PR got a bit out of hand scope-wise and ends up doing a few things, hopefully reviewing it isn't too much of a pain!

This PR accomplishes the following:

• Adds and implements async variants of the embedded::wifi::Wifi trait
• Plus one more, wait_for_event to asynchronously wait for any Wifi related events
• splits wifi into two parts, device and controller
  • where device is the thing passed into stacks for packet send/recv
  • where controller handles the link/connection
• Closes wifi_connect and co don't use the svc configuration parameters #120
• Closes embedded-svc::Wifi::is_started is wrong #126
• Moves the transmit waker inside the check as to whether we actually sent the packet! This didn't break anything but was less efficient
  • This can actually be improved even further later on down the line, see Improve efficiency of embassy::net::Stack.poll() embassy-rs/embassy#1212 (comment)
• Clears scan memory on failure to avoid memory leaks

[bjoernQ]

Nice changes - especially "splits wifi into two parts, device and controlle" is something I already had in mind.

Unfortunately, this breaks esp-now examples since it needs the wifi adapter to be in STA mode and started which always was the case after initialize before

Second thing, compiling embassy-dhcp / embassy-esp-now generates compiler errors

error[E0599]: `&'static AtomicWaker` is not an iterator
   --> esp-wifi\src\wifi\os_adapter.rs:932:19
    |
932 |     event.waker().map(|w| w.wake());
    |                   ^^^ `&'static AtomicWaker` is not an iterator
    |
   ::: ....\.cargo\registry\src\github.com-1ecc6299db9ec823\embassy-sync-0.1.0\src\waitqueue\waker.rs:59:1
    |
59  | pub struct AtomicWaker {
    | ---------------------- doesn't satisfy `AtomicWaker: Iterator`
    |
    = note: the following trait bounds were not satisfied:
            `&'static AtomicWaker: Iterator`
            which is required by `&mut &'static AtomicWaker: Iterator`
            `AtomicWaker: Iterator`
            which is required by `&mut AtomicWaker: Iterator`

[MabezDev]

Oops, my commit last night broke it 😅, should be fixed now :)

[bjoernQ]

LGTM! Thanks!

[SergioGasquez]

LGTM! I have very limited knowledge about esp-wifi but the changes make sense to me. I've tested the dhcp example to check #120, and it was working fine for me.

Just two small question, that can ofc be addressed, if needed, in other PRs:

• Shall we cover embassy_dhcp example in CI? embassy_esp_now and esp-now are not covered either.
• Shall we include a column for async wifi in the current support table?

[bjoernQ]

LGTM! I have very limited knowledge about esp-wifi but the changes make sense to me. I've tested the dhcp example to check #120, and it was working fine for me.

Just two small question, that can ofc be addressed, if needed, in other PRs:

• Shall we cover embassy_dhcp example in CI? embassy_esp_now and esp-now are not covered either.

That is a good idea! As you said probably in a separate PR

• Shall we include a column for async wifi in the current support table?

Not sure since it's not chip specific. Now if we have WiFi we also have Async-WiFi

[MabezDev]

Thanks for the reviews! I'll create an issue about adding CI and merge this now :)