Apds9960 polling without interrupt pin

[batkay]

Description
This change allows for I2C communication with APDS9960 sensor without using the interrupt pin. If a sample is not available, it will block for the default amount of time between samples (2.78ms) before trying again. This allows it to work with boards like the Adafruit APDS9960 breakout with a QWIIC connector.

Specific Changes:

• Made interrupt pin assignment optional
• Added new configuration option to disable the interrupt
• Use status register to determine whether a sample is ready or not
• Sleep if a sample is not ready, and try again in non interrupt mode

By default, interrupt pin is enabled when the int-gpios property is provided so older projects are not effected.

Testing
Build the sample APDS9960 sensor code with CONFIG_APDS9960_INTERRUPT_PIN set to n and CONFIG_APDS9960_TRIGGER_GLOBAL_THREAD set to n, or alternatively delete the property int-gpios from the devicetree overlay.

Logic analyzer shows i2c checking status, and waiting if a sample is not ready

RTT viewer shows the proximity and ambient light data being printed (same as before behavior)

[github-actions]

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[ubieda]

Thanks for your contribution and for the detailed testing proof. I've left some comments I've caught at a glance. Let me know your thoughts!

[ubieda]

Specific Changes:

• Made interrupt pin assignment optional
• Added new configuration option to disable the interrupt
• Use status register to determine whether a sample is ready or not
• Sleep if a sample is not ready, and try again in non interrupt mode

By default, interrupt pin is enabled when the int-gpios property is provided so older projects are not effected.

Also, it seems some changes got lost in the way. Please revisit the commits and their contents. As it is right now, it seems only the driver changes are present in the PR.

[batkay]

@ubieda Just as a response to the previous comment, some of the changes are in the same commits. For example, making the interrupt optional and creating config options to enable/ disable its functionality were in the same commit since it didn't make sense (in my opinion) to break those up.

[ubieda]

The changes seem to meet the initial review.

I'm a bit concerned that apds9960_sample_fetch() is turning cumbersome with a bunch of ifdef directives, but I acknowledge it was like that to begin with.

Let's wait for other reviewers to chime in. Thanks for your contribution!