Re: [PATCH v4 3/6] iio: adc: ad7173: refactor ain and vref selection

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 31 May 2024 22:42:29 +0300
Dumitru Ceclan via B4 Relay <devnull+dumitru.ceclan.analog.com@kernel.org> wrote:

> From: Dumitru Ceclan <dumitru.ceclan@analog.com>
> 
> Move validation of analog inputs and reference voltage selection to
> separate functions to reduce the size of the channel config parsing
> function and improve readability.
> Add defines for the number of analog inputs in a channel.
> 
> Reviewed-by: David Lechner <dlechner@baylibre.com>
> Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
> ---
>  drivers/iio/adc/ad7173.c | 71 ++++++++++++++++++++++++++++++++++--------------
>  1 file changed, 50 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
> index 6e249628bc64..a20831d99aa5 100644
> --- a/drivers/iio/adc/ad7173.c
> +++ b/drivers/iio/adc/ad7173.c
> @@ -60,6 +60,7 @@
>  #define AD7173_CH_SETUP_AINPOS_MASK	GENMASK(9, 5)
>  #define AD7173_CH_SETUP_AINNEG_MASK	GENMASK(4, 0)
>  
> +#define AD7173_NO_AINS_PER_CHANNEL	2
>  #define AD7173_CH_ADDRESS(pos, neg) \
>  	(FIELD_PREP(AD7173_CH_SETUP_AINPOS_MASK, pos) | \
>  	 FIELD_PREP(AD7173_CH_SETUP_AINNEG_MASK, neg))
> @@ -623,6 +624,7 @@ static int ad7173_setup(struct iio_dev *indio_dev)
>  static unsigned int ad7173_get_ref_voltage_milli(struct ad7173_state *st,
>  						 u8 reference_select)
>  {
> +	struct device *dev = &st->sd.spi->dev;
>  	int vref;
>  
>  	switch (reference_select) {
> @@ -646,9 +648,11 @@ static unsigned int ad7173_get_ref_voltage_milli(struct ad7173_state *st,
>  		return -EINVAL;
>  	}
>  
> -	if (vref < 0)
> +	if (vref < 0) {
> +		dev_err(dev, "Cannot use reference %u. Error:%d\n",
> +			reference_select, vref);
>  		return vref;
> -
> +	}
>  	return vref / (MICRO / MILLI);
>  }
>  
> @@ -905,13 +909,50 @@ static int ad7173_register_clk_provider(struct iio_dev *indio_dev)
>  					   &st->int_clk_hw);
>  }
>  
> +static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
> +					      const unsigned int ain[AD7173_NO_AINS_PER_CHANNEL])
I was late to the game in replying to previous thread.

This is neater without the loop and with 2 parameters.  Anyhow see reply to v3.

If you end up respining for other reasons consider doing that as well.
Maybe keep the struct device *dev though which I suggested dropping as
looking at the full patch it is more consistent to keep that.

> +{
> +	struct device *dev = &st->sd.spi->dev;
> +
> +	for (int i = 0; i < AD7173_NO_AINS_PER_CHANNEL; i++) {
> +		if (ain[i] < st->info->num_inputs)
> +			continue;
> +
> +		return dev_err_probe(dev, -EINVAL,
> +			"Input pin number out of range for pair (%d %d).\n",
> +			ain[0], ain[1]);
> +	}
> +
> +	return 0;
> +}
> +
> +static int ad7173_validate_reference(struct ad7173_state *st, int ref_sel)
> +{
> +	struct device *dev = &st->sd.spi->dev;
> +	int ret;
> +
> +	if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF && !st->info->has_int_ref)
> +		return dev_err_probe(dev, -EINVAL,
> +			"Internal reference is not available on current model.\n");
> +
> +	if (ref_sel == AD7173_SETUP_REF_SEL_EXT_REF2 && !st->info->has_ref2)
> +		return dev_err_probe(dev, -EINVAL,
> +			"External reference 2 is not available on current model.\n");
> +
> +	ret = ad7173_get_ref_voltage_milli(st, ref_sel);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
>  static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
>  {
>  	struct ad7173_channel *chans_st_arr, *chan_st_priv;
>  	struct ad7173_state *st = iio_priv(indio_dev);
>  	struct device *dev = indio_dev->dev.parent;
>  	struct iio_chan_spec *chan_arr, *chan;
> -	unsigned int ain[2], chan_index = 0;
> +	unsigned int ain[AD7173_NO_AINS_PER_CHANNEL], chan_index = 0;
>  	int ref_sel, ret, num_channels;
>  
>  	num_channels = device_get_child_node_count(dev);
> @@ -965,11 +1006,9 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
>  		if (ret)
>  			return ret;
>  
> -		if (ain[0] >= st->info->num_inputs ||
> -		    ain[1] >= st->info->num_inputs)
> -			return dev_err_probe(dev, -EINVAL,
> -				"Input pin number out of range for pair (%d %d).\n",
> -				ain[0], ain[1]);
> +		ret = ad7173_validate_voltage_ain_inputs(st, ain);
> +		if (ret)
> +			return ret;
>  
>  		ret = fwnode_property_match_property_string(child,
>  							    "adi,reference-select",
> @@ -980,19 +1019,9 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
>  		else
>  			ref_sel = ret;
>  
> -		if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF &&
> -		    !st->info->has_int_ref)
> -			return dev_err_probe(dev, -EINVAL,
> -				"Internal reference is not available on current model.\n");
> -
> -		if (ref_sel == AD7173_SETUP_REF_SEL_EXT_REF2 && !st->info->has_ref2)
> -			return dev_err_probe(dev, -EINVAL,
> -				"External reference 2 is not available on current model.\n");
> -
> -		ret = ad7173_get_ref_voltage_milli(st, ref_sel);
> -		if (ret < 0)
> -			return dev_err_probe(dev, ret,
> -					     "Cannot use reference %u\n", ref_sel);
> +		ret = ad7173_validate_reference(st, ref_sel);
> +		if (ret)
> +			return ret;
>  
>  		if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF)
>  			st->adc_mode |= AD7173_ADC_MODE_REF_EN;
>