Clock feature

[IFX-Anusha]

• machine.freq() implementation for setting clock by the user
• Remove clock init from I2S and modified tests
• Documentation

[NikhitaR-IFX]

Nice!🚀

[jaenrig-ifx]

Very good! 😃 A couple of things that we should refine 📏

[jaenrig-ifx]

We should keep this part checking that the rate is a valid one or?
Otherwise, the use could pass any integer. But actually only the ones filtered where valid?

Additionally, here I would check if the clock is properly for that rate, and raise exception if that is not the case.

[jaenrig-ifx]

These flags would not be sufficient to properly check the current clock configuration, because there aren´t deinited anywhere or?

Think of the following case:

• you set the machine.freq(AUDIO_I2S_98_MHZ)
• the clock_set_i2s = true;
• then you set machine.freq(AUDIO_PDM_22_579_200_HZ)
• then clock_set_pdm = true;
• then you try to use machine.I2S. It will consider that the i2s clock is set, but actually isn´t.

I would say inside the i2s or the pdm we need to check the right configuration (also for the given rates). A function to get freq setup can be called by each module (i2s, pdm, ...) and they can check if that is the right one. Raise an exception otherwise.

Alternatively, you have to keep track of those 2 flags (and any future one), and set them to false, when other functions reconfigure those clocks. I think that is less maintainable because every function needs to keep track of "which setup an I going to break".

[ramya-subramanyam]

Looks good!

[jaenrig-ifx]

Nice 👯