Re: [PATCH v6 8/9] iio: pressure: bmp280: Add SCALE, RAW values in channels and refactorize them

[Jonathan Cameron <jic23@kernel.org>]

On Wed,  8 May 2024 18:52:06 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> Add extra IIO_CHAN_INFO_SCALE and IIO_CHAN_INFO_RAW channels in order
> to be able to calculate the processed value with standard userspace
> IIO tools. Can be used for triggered buffers as well.
> 
> Even though it is not a good design choice to have SCALE, RAW and
> PROCESSED together, the PROCESSED channel is kept for ABI compatibility.
> 
> While at it, separate BMPxxx and BMExxx device channels since BME
> supports also humidity measurements.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
num channels is now ARRAY_SIZE(xxx) for all of these rather than
the previous trick of using the same array and different numbers of channels.

As such I think you can just replace the 2, 3 with ARRAY_SIZE(bmp280_channels)
and ARRAY_SIZE(bme280_channels) which will give more obviously correct
and maintainable code.

Jonathan


> ---
>  drivers/iio/pressure/bmp280-core.c | 86 +++++++++++++++++++++++++++---
>  1 file changed, 78 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 70ce37370ac6..3f8144a0355b 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -137,17 +137,45 @@ enum {
>  static const struct iio_chan_spec bmp280_channels[] = {
>  	{
>  		.type = IIO_PRESSURE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  	{
>  		.type = IIO_TEMP,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
> +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> +	},
> +};
> +
> +static const struct iio_chan_spec bme280_channels[] = {
> +	{
> +		.type = IIO_PRESSURE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
> +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> +	},
> +	{
> +		.type = IIO_TEMP,
> +		/* PROCESSED maintained for ABI backwards compatibility */
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  	{
>  		.type = IIO_HUMIDITYRELATIVE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  };
> @@ -155,21 +183,20 @@ static const struct iio_chan_spec bmp280_channels[] = {
>  static const struct iio_chan_spec bmp380_channels[] = {
>  	{
>  		.type = IIO_PRESSURE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>  					   BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
>  	},
>  	{
>  		.type = IIO_TEMP,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> -				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> -		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> -					   BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
> -	},
> -	{
> -		.type = IIO_HUMIDITYRELATIVE,
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
>  					   BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
> @@ -537,6 +564,49 @@ static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
>  		default:
>  			return -EINVAL;
>  		}
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_HUMIDITYRELATIVE:
> +			ret = data->chip_info->read_humid(data, &chan_value);
> +			if (ret)
> +				return ret;
> +
> +			*val = chan_value;
> +			return IIO_VAL_INT;
> +		case IIO_PRESSURE:
> +			ret = data->chip_info->read_press(data, &chan_value);
> +			if (ret)
> +				return ret;
> +
> +			*val = chan_value;
> +			return IIO_VAL_INT;
> +		case IIO_TEMP:
> +			ret = data->chip_info->read_temp(data, &chan_value);
> +			if (ret)
> +				return ret;
> +
> +			*val = chan_value;
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_HUMIDITYRELATIVE:
> +			*val = data->chip_info->humid_coeffs[0];
> +			*val2 = data->chip_info->humid_coeffs[1];
> +			return data->chip_info->humid_coeffs_type;
> +		case IIO_PRESSURE:
> +			*val = data->chip_info->press_coeffs[0];
> +			*val2 = data->chip_info->press_coeffs[1];
> +			return data->chip_info->press_coeffs_type;
> +		case IIO_TEMP:
> +			*val = data->chip_info->temp_coeffs[0];
> +			*val2 = data->chip_info->temp_coeffs[1];
> +			return data->chip_info->temp_coeffs_type;
> +		default:
> +			return -EINVAL;
> +		}
>  	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
>  		switch (chan->type) {
>  		case IIO_HUMIDITYRELATIVE:
> @@ -903,7 +973,7 @@ const struct bmp280_chip_info bme280_chip_info = {
>  	.num_chip_id = ARRAY_SIZE(bme280_chip_ids),
>  	.regmap_config = &bmp280_regmap_config,
>  	.start_up_time = 2000,
> -	.channels = bmp280_channels,
> +	.channels = bme280_channels,
>  	.num_channels = 3,
>  
>  	.oversampling_temp_avail = bmp280_oversampling_avail,