Re: [PATCH v15 6/6] mux: add NXP MC33978/MC34978 AMUX driver

[Alvin Šipraga]

On Fri, Jul 10, 2026 at 12:13:55PM +0200, Oleksij Rempel wrote:
> Add a mux-control driver for the 24-to-1 analog multiplexer (AMUX)
> embedded in the NXP MC33978/MC34978 Multiple Switch Detection
> Interface (MSDI) devices.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>

Reviewed-by: Alvin Šipraga <alvin.sipraga@xxxxxxxxxx>

One small comment below.

[...]

> +static int mc33978_mux_set(struct mux_control *mux, int state)
> +{
> +	struct mux_chip *mux_chip = mux->chip;
> +	struct mc33978_mux_priv *priv = mux_chip_priv(mux_chip);
> +	int ret;
> +
> +	if (state < 0 || state >= MC33978_NUM_AMUX_CH)
> +		return -EINVAL;
> +
> +	ret = regmap_update_bits(priv->map, MC33978_REG_AMUX_CTRL,
> +				 MC33978_AMUX_CTRL_MASK, state);
> +	if (ret)
> +		dev_err(priv->dev, "failed to set AMUX channel %d: %d\n",
> +			state, ret);

Especially for iio, I can imagine a consumer might keep polling even if
the mux .set returns an error. So maybe ratelimit this print?

> +
> +	return ret;
> +}
> +
> +static const struct mux_control_ops mc33978_mux_ops = {
> +	.set = mc33978_mux_set,
> +};