drivers: sensor: APDS9306: Lux conversion

[Kampi]

• Add lux conversion to APDS-9306 driver
• Change settings of gain, resolution and frequency to index-based settings
• Add Device Tree overlay sample for APDS-9306
• Fix wrong board name in light_polling README
• Add value checks for the attribute set API call
• Remove the reading of the sensor attributes from the sensor and use buffered values instead
• Rename frequency property to measurement period

Closes #91104

[msalau]

There is a disconnect between gain property set in the devicetree and the ALS_GAIN register. Property defines the desired gain value, but register expects an index, not the value itself. The same issue exists for the ALS_MEAS_RATE register values (resolution and rate).

A possible solution:

1. Reorder gain values in the yaml file to match the datasheet:

  gain:
    type: int
    default: 1
    enum:
      - 1
      - 3
      - 6
      - 9
      - 18

2. Save the gain enum's index in config:

.gain_idx = DT_INST_ENUM_IDX(inst, gain), \

3. Write index into the register:

	value = config->gain_idx;
	LOG_DBG("Write configuration 0x%x to register 0x%x", value, APDS9306_REGISTER_ALS_GAIN);
	if (i2c_reg_write_byte_dt(&config->i2c, APDS9306_REGISTER_ALS_GAIN, value)) {
		return -EFAULT;
	}

This should fix initialization, I believe.

I can't comment about the conversion part though.

addressed

[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[kartben]

Hi, please wait a bit before accepting this PR. I want to check the results against a lux meter and I will do this this week.

It probably won't make it in 4.2 anyway as it's now entered feature freeze, so no rush :)

[MaureenHelm]

please wait a bit before accepting this PR. I want to check the results against a lux meter and I will do this this week.

Adding the DNM label to prevent merge. Please remove the label when you're done testing

[Kampi]

please wait a bit before accepting this PR. I want to check the results against a lux meter and I will do this this week.

Adding the DNM label to prevent merge. Please remove the label when you're done testing

Thanks :)
I´ve tested it already and compared it against a cheap luxmeter. The results are good.

Edit: How can I remove the label?