Re: [PATCH v6 9/9] iio: adc: ad7173: Add support for AD411x devices

[Nuno Sá]

On Thu, 2024-06-06 at 19:07 +0300, Dumitru Ceclan via B4 Relay wrote:
> From: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx>
> 
> Add support for AD4111/AD4112/AD4114/AD4115/AD4116.
> 
> The AD411X family encompasses a series of low power, low noise, 24-bit,
> sigma-delta analog-to-digital converters that offer a versatile range of
> specifications.
> 
> This family of ADCs integrates an analog front end suitable for processing
> both fully differential and single-ended, bipolar voltage inputs
> addressing a wide array of industrial and instrumentation requirements.
> 
> - All ADCs have inputs with a precision voltage divider with a division
>   ratio of 10.
> - AD4116 has 5 low level inputs without a voltage divider.
> - AD4111 and AD4112 support current inputs (0 mA to 20 mA) using a 50ohm
>   shunt resistor.
> 
> Signed-off-by: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx>
> ---
>  drivers/iio/adc/ad7173.c | 317 ++++++++++++++++++++++++++++++++++++++++++----
> -
>  1 file changed, 285 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
> index 58da5717fd36..cfcd12447e24 100644
> --- a/drivers/iio/adc/ad7173.c
> +++ b/drivers/iio/adc/ad7173.c
> 
...

>  static const struct ad7173_device_info ad7172_2_device_info = {
>  	.name = "ad7172-2",
>  	.id = AD7172_2_ID,
> -	.num_inputs = 5,
> +	.num_voltage_in = 5,
>  	.num_channels = 4,
>  	.num_configs = 4,
>  	.num_gpios = 2,
> +	.higher_gpio_bits = false,

No need to explicitly set to 'false'. Ditto for the other places...

...

> 
>  static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
>  					      unsigned int ain0, unsigned int
> ain1)
>  {
> @@ -946,15 +1145,30 @@ static int ad7173_validate_voltage_ain_inputs(struct
> ad7173_state *st,
>  	    st->info->has_pow_supply_monitoring)
>  		return 0;
>  
> -	special_input0 = AD7173_IS_REF_INPUT(ain0);
> -	special_input1 = AD7173_IS_REF_INPUT(ain1);
> +	special_input0 = AD7173_IS_REF_INPUT(ain0) ||
> +			 (ain0 == AD4111_VINCOM_INPUT && st->info-
> >has_vincom_input);
> +	special_input1 = AD7173_IS_REF_INPUT(ain1) ||
> +			 (ain1 == AD4111_VINCOM_INPUT && st->info-
> >has_vincom_input);
> +

Wondering... can ain1 (or ain0) be AD4111_VINCOM_INPUT and !st->info-
>has_vincom_input? Would that actually be acceptable? It would assume it's not
so we should check that right? Or am I missing something?

- Nuno Sá