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From: Vasileios Amoiridis <vassilisamir@gmail.com>
Date: Sun, 12 May 2024 20:48:45 +0200
To: Jonathan Cameron <jic23@kernel.org>
Cc: Vasileios Amoiridis <vassilisamir@gmail.com>, lars@metafoo.de,
	andriy.shevchenko@linux.intel.com, ang.iglesiasg@gmail.com,
	mazziesaccount@gmail.com, ak@it-klinger.de,
	petre.rodan@subdimension.ro, phil@raspberrypi.com, 579lpy@gmail.com,
	linus.walleij@linaro.org, semen.protsenko@linaro.org,
	linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 8/9] iio: pressure: bmp280: Add SCALE, RAW values in
 channels and refactorize them
Message-ID: <20240512184845.GB24095@vamoiridPC>
References: <20240508165207.145554-1-vassilisamir@gmail.com>
 <20240508165207.145554-9-vassilisamir@gmail.com>
 <20240512132914.34f2a571@jic23-huawei>
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In-Reply-To: <20240512132914.34f2a571@jic23-huawei>

On Sun, May 12, 2024 at 01:29:14PM +0100, Jonathan Cameron wrote:
> 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
> 

Hi Jonathan!

Indeed, this is a very good addition!!!

Cheers,
Vasilis

> 
> > ---
> >  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,
>