Implementing `impl From<SystemClock> for Hertz` is a footgun, as
SystemClock is not Copy, so the automatic conversion consumes the
owned clock.
This is visible in the example i2c.rs:
```
let mut i2c = hal::I2C::i2c1(
pac.I2C1,
sda_pin,
scl_pin, // Try `not_an_scl_pin` here
400.kHz(),
&mut pac.RESETS,
clocks.peripheral_clock,
);
```
If the user wants to use both `i2c0` and `i2c1` at the same time,
copying from this example won't work:
```
error[E0382]: use of moved value: `clocks.peripheral_clock`
--> rp2040-hal/examples/i2c.rs:106:9
|
97 | clocks.peripheral_clock,
| ----------------------- value moved here
...
106 | clocks.peripheral_clock,
| ^^^^^^^^^^^^^^^^^^^^^^^ value used here after move
|
= note: move occurs because `clocks.peripheral_clock` has type
`PeripheralClock`, which does not implement the `Copy` trait
```
As getting the frequency from a clock doesn't really need ownership,
changing it to `impl From<&SystemClock> for Hertz` is both more
logical and provides better usability.
This is, however, a breaking change: Code relying on this trait
implementation needs to be changed by adding a `&`.
Fix: The divider for watchdog tick generation is now being set to the
source clock frequency in MHz, instead of the clock frequency in Hz.
Watchdog ticks will now be generated at 1 microsecond intervals
as intended.
The newer version of svd2rust used in the PAC marks write_with_zero calls as unsafe, where the old one did not.
This PR wraps the only 2 calls instances of this in the HAL with unsafe blocks to fix the compile errors.
* Improve clock frequency stuff for uninitialized clocks
- Made clocks singletons so the frequency handling actually works as expected
- Added initial frequencies
- Improved the docs
- Added a Clock trait
* Add pico examples.
These have the benefit of knowing which external crystal is attached.
Even though it always should be a 12 MHz crystal.
Thus we can setup the clocks properly
I also changed the rp2040 examples to work out of the box for pico boards since that will probably be used most of the time
Bring in line with atsamd-hal GPIO v2
Copied as much as possible. Docs lifted mostly as-is.
Also add sample BSP for the Feather RP2040 in boards/feather_rp2040
May include a few random fixes from currently futile attempt to get doctests working.
