1370: stm32/i2c: fix races when using dma. r=Dirbaio a=xoviat
This change addresses two races:
1. It removes the `chunks_transferred` state variable that is modified inside the interrupt. Analysis of the code reveals that the only time the waker can be woken is when `chunks_transferred` is incremented. Therefore, waking is enough to signal the `poll_fn` that the `chunks_transferred` has incremented. Moving to `remaining_len` clarifies the code, since there is no need to track how many chunks are remaining.
2. It moves the start of the transfer until after the waker is registered, which could theoretically occur if the clock speed is very low, but probably never would even if this wasn't fixed.
There is another race that I noticed: between writes the waker may not yet be registered. In that case, the code would simply be stuck and the `poll_fn` would never be woken. There is no way to resolve this without broadening the scope of the analysis, and this will likely never occur.
Co-authored-by: xoviat <xoviat@users.noreply.github.com>
1371: RTC r=Dirbaio a=xoviat
This adds RTC for most of the stm32 chips. Nearly all of the work was not done by me, but I took it the last bit by disabling the chips that weren't working. I think it would be easier to enable them in future PRs if requested.
1374: stm32: remove TIMX singleton when used on timer driver r=Dirbaio a=xoviat
After multiple ways of looking at this, this is the best solution I could think of.
Co-authored-by: Mathias <mk@blackbird.online>
Co-authored-by: xoviat <xoviat@users.noreply.github.com>
1360: stm32/rcc: add i2s pll on some f4 micros r=Dirbaio a=xoviat
Adds the i2s pll on some f4 micros.
1361: Executor: Replace unnecessary atomics in runqueue r=Dirbaio a=GrantM11235
Only the head pointer needs to be atomic. The `RunQueueItem` pointers are only loaded and stored, and never concurrently
Co-authored-by: xoviat <xoviat@users.noreply.github.com>
Co-authored-by: Grant Miller <GrantM11235@gmail.com>
1330: stm32/pwm: add complementary pwm r=Dirbaio a=xoviat
This implements complementary PWM with dead time on many supported targets. The specific dead-time programming functions are passed through directly to the user, which is a bit ugly but the best compromise I could reach for now.
Co-authored-by: xoviat <xoviat@users.noreply.github.com>
