Re: [PATCH v2 2/2] iio: adc: add Nuvoton NCT720x ADC driver

[David Lechner <dlechner@baylibre.com>]

On 12/5/24 12:22 PM, David Lechner wrote:
> On 12/3/24 3:15 AM, Eason Yang wrote:


>> +static int nct720x_read_raw(struct iio_dev *indio_dev,
>> +			    struct iio_chan_spec const *chan,
>> +			    int *val, int *val2, long mask)
>> +{
>> +	int index = nct720x_chan_to_index[chan->address];
>> +	u16 volt;
>> +	unsigned int value;
>> +	int err;
>> +	struct nct720x_chip_info *chip = iio_priv(indio_dev);
>> +
>> +	if (chan->type != IIO_VOLTAGE)
>> +		return -EOPNOTSUPP;
>> +
>> +	guard(mutex)(&chip->access_lock);
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		err = regmap_read(chip->regmap16, REG_VIN[index], &value);
>> +		if (err < 0)
>> +			return err;
>> +		volt = (u16)value;
>> +		*val = volt >> 3;
> 
> It seems strange that this is 13 bits when the chips are 8 and 12 bit.
> 
>> +		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		/* From the datasheet, we have to multiply by 0.0004995 */
> 
> The scale is the same for both 8 bit and 12 bit chips?
> 
>> +		*val = 0;
>> +		*val2 = 499500;
>> +		return IIO_VAL_INT_PLUS_NANO;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +

Sorry, I got confused. The difference between the two chips is the
number of channels, not the number of bits. Please ignore these two
comments.