Re: [PATCH 2/2] iio: addac: ad74413r: wire up digital-input-threshold-microvolt DT property

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 23 Jun 2023 13:33:26 +0200
Rasmus Villemoes <linux@rasmusvillemoes.dk> wrote:

> The threshold is common to all channels configured as digital
> input.
> 
> So far, we have not seen the settings in the DIN_THRESH affecting
> functions other than digital input, but with a4cba07e64e6 ("iio:
> addac: ad74413: don't set DIN_SINK for functions other than digital
> input") in mind, do not read and apply the
> digital-input-threshold-microvolt setting unless at least one channel
> has been configured as one of the digital input variants.
> 
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
LGTM. Will pick up once the minor change in binding is done if no
other feedback comes in.

Thanks,

Jonathan

> ---
>  drivers/iio/addac/ad74413r.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
> index e3366cf5eb31..efdd7fdd7ab9 100644
> --- a/drivers/iio/addac/ad74413r.c
> +++ b/drivers/iio/addac/ad74413r.c
> @@ -129,6 +129,12 @@ struct ad74413r_state {
>  #define AD74413R_GPO_CONFIG_COMPARATOR		0b011
>  #define AD74413R_GPO_CONFIG_HIGH_IMPEDANCE	0b100
>  
> +#define AD74413R_REG_DIN_THRESH		0x22
> +#define AD74413R_DIN_COMP_THRESH_MASK	GENMASK(5, 1)
> +#define AD74413R_DIN_THRESH_MODE	BIT(0)
> +#define AD74413R_DIN_THRESH_MODE_16V	BIT(0)
> +#define AD74413R_DIN_THRESH_MODE_AVDD	0
> +
>  #define AD74413R_REG_ADC_CONV_CTRL	0x23
>  #define AD74413R_CONV_SEQ_MASK		GENMASK(9, 8)
>  #define AD74413R_CONV_SEQ_ON		0b00
> @@ -1446,6 +1452,20 @@ static int ad74413r_probe(struct spi_device *spi)
>  	}
>  
>  	if (st->num_comparator_gpios) {
> +		u32 thresh, val, mask;
> +
> +		if (!device_property_read_u32(st->dev, "digital-input-threshold-microvolt",
> +					      &thresh)) {
> +			val = thresh/500000 - 1;
> +			val = FIELD_PREP(AD74413R_DIN_COMP_THRESH_MASK, val);
> +			val |= AD74413R_DIN_THRESH_MODE_16V;
> +			mask = AD74413R_DIN_COMP_THRESH_MASK | AD74413R_DIN_THRESH_MODE;
> +			ret = regmap_update_bits(st->regmap, AD74413R_REG_DIN_THRESH,
> +						 mask, val);
> +			if (ret)
> +				return ret;
> +		}
> +
>  		st->comp_gpiochip.owner = THIS_MODULE;
>  		st->comp_gpiochip.label = st->chip_info->name;
>  		st->comp_gpiochip.base = -1;