Re: [PATCH v4 4/4] iio: adc: ad7192: Add AD7194 support

[David Lechner <dlechner@xxxxxxxxxxxx>]

On Wed, Feb 28, 2024 at 6:26 AM Alisa-Dariana Roman
<alisadariana@xxxxxxxxx> wrote:
>

...

> @@ -1012,6 +1052,73 @@ static const struct iio_chan_spec ad7193_channels[] = {
>         IIO_CHAN_SOFT_TIMESTAMP(14),
>  };
>
> +static struct iio_chan_spec ad7194_channels[] = {
> +       AD7193_DIFF_CHANNEL(0, 1, 0, AD7194_CH_AIN1),
> +       AD7193_DIFF_CHANNEL(1, 2, 0, AD7194_CH_AIN2),
> +       AD7193_DIFF_CHANNEL(2, 3, 0, AD7194_CH_AIN3),
> +       AD7193_DIFF_CHANNEL(3, 4, 0, AD7194_CH_AIN4),
> +       AD7193_DIFF_CHANNEL(4, 5, 0, AD7194_CH_AIN5),
> +       AD7193_DIFF_CHANNEL(5, 6, 0, AD7194_CH_AIN6),
> +       AD7193_DIFF_CHANNEL(6, 7, 0, AD7194_CH_AIN7),
> +       AD7193_DIFF_CHANNEL(7, 8, 0, AD7194_CH_AIN8),
> +       AD7193_DIFF_CHANNEL(8, 9, 0, AD7194_CH_AIN9),
> +       AD7193_DIFF_CHANNEL(9, 10, 0, AD7194_CH_AIN10),
> +       AD7193_DIFF_CHANNEL(10, 11, 0, AD7194_CH_AIN11),
> +       AD7193_DIFF_CHANNEL(11, 12, 0, AD7194_CH_AIN12),
> +       AD7193_DIFF_CHANNEL(12, 13, 0, AD7194_CH_AIN13),
> +       AD7193_DIFF_CHANNEL(13, 14, 0, AD7194_CH_AIN14),
> +       AD7193_DIFF_CHANNEL(14, 15, 0, AD7194_CH_AIN15),
> +       AD7193_DIFF_CHANNEL(15, 16, 0, AD7194_CH_AIN16),
> +       AD719x_TEMP_CHANNEL(16, AD7194_CH_TEMP),
> +       IIO_CHAN_SOFT_TIMESTAMP(17),
> +};

Based on the discussion on the v3 patch I was expecting this to be
fully dynamic rather than having a fixed number of channels since
there are so many possible combinations and the fact that
pseudo-differential channels should be using AD7193_CHANNEL() rather
than AD7193_DIFF_CHANNEL().

> +
> +static int ad7192_parse_channel(struct fwnode_handle *child)
> +{
> +       u32 reg, ain[2];
> +       int ret;
> +
> +       ret = fwnode_property_read_u32(child, "reg", &reg);
> +       if (ret)
> +               return ret;
> +
> +       if (!in_range(reg, AD7194_CH_DIFF_START, AD7194_CH_DIFF_NR))
> +               return -EINVAL;
> +
> +       ret = fwnode_property_read_u32_array(child, "diff-channels", ain,
> +                                            ARRAY_SIZE(ain));
> +       if (ret)
> +               return ret;
> +
> +       if (!in_range(ain[0], AD7194_CH_AIN0_START, AD7194_CH_AIN0_NR) ||
> +           !in_range(ain[1], AD7194_CH_AIN1_START, AD7194_CH_AIN1_NR))
> +               return -EINVAL;
> +
> +       reg--;
> +       ad7194_channels[reg].channel = ain[0];
> +       ad7194_channels[reg].channel2 = ain[1];

Needs to set ad7194_channels[reg].differential = ain[1] != 0.

> +       ad7194_channels[reg].address = AD7194_CH_DIFF(ain[0], ain[1]);
> +
> +       return 0;
> +}
> +