Re: [PATCH v3 3/3] iio: adc: ti-ads112c14: add continuous mode support

On Fri, Aug 07, 2026 at 04:19:48PM -0500, David Lechner (TI) wrote:
> Add support for continuous mode in the TI ADS112C14 ADC driver. In this
> mode the ADC itself is starting each conversion, so we add a trigger
> based on the DRDY interrupt to read each sample. This mode is also
> limited in that only one channel can be enabled at a time since the
> chip does not have a sequencer or simultaneous sampling capability.
> Continuous mode will only be used when this new trigger is the current
> trigger.

...

> static irqreturn_t ads112c14_trigger_handler(int irq, void *private)

>  	struct iio_poll_func *pf = private;
>  	struct iio_dev *indio_dev = pf->indio_dev;
>  	struct ads112c14_data *data = iio_priv(indio_dev);
> +	unsigned int scan_mask_len = iio_get_masklength(indio_dev);

This is from indio_dev, which is defined two lines up, so this, longer one, can
be bumped one line up.

>  	u32 offset = 0;
>  	u32 i;
>  	int ret;
>  
> +	if (iio_trigger_using_own(indio_dev)) {
> +		i = find_first_bit(indio_dev->active_scan_mask, scan_mask_len);
> +		if (i >= scan_mask_len)

'>' is redundant, '==' suffices.

> +			goto out;
> +
> +		ret = ads112c14_scan_read(data, (u8 *)&data->scan[0]);
> +		if (ret) {
> +			const struct iio_chan_spec *chan = &indio_dev->channels[i];
> +
> +			dev_err_once(indio_dev->dev.parent,
> +				     "failed to read channel %d: %pe; additional errors will be suppressed\n",
> +				     chan->channel, ERR_PTR(ret));
> +			goto out;
> +		}
> +
> +		iio_push_to_buffers_with_ts(indio_dev, data->scan,
> +					    sizeof(data->scan), pf->timestamp);
> +		goto out;
> +	}

...

> +static int ads112c14_buffer_postenable(struct iio_dev *indio_dev)
> +{
> +	unsigned int scan_mask_len = iio_get_masklength(indio_dev);
> +	struct ads112c14_data *data = iio_priv(indio_dev);
> +	const struct iio_chan_spec *chan;
> +	unsigned int i;
> +	int ret;
> +
> +	if (!ads112c14_using_drdy_trigger(indio_dev))
> +		return 0;

> +	i = find_first_bit(indio_dev->active_scan_mask, scan_mask_len);
> +	if (i >= scan_mask_len)
> +		return -EINVAL;
> +
> +	chan = &indio_dev->channels[i];

These lines repeat what you have in ads112c14_trigger_handler(). Perhaps
a helper to return a channel or error pointer or NULL?

> +	guard(mutex)(&data->lock);
> +
> +	ret = ads112c14_prepare_channel(data, chan);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_assign_bits(data->regmap, ADS112C14_REG_DEVICE_CFG,
> +				 ADS112C14_DEVICE_CFG_CONV_MODE,
> +				 ADS112C14_DEVICE_CFG_CONV_MODE_CONTINUOUS);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_write(data->regmap, ADS112C14_REG_CONVERSION_CTRL,
> +			   ADS112C14_CONVERSION_CTRL_START);
> +	if (ret) {
> +		regmap_assign_bits(data->regmap, ADS112C14_REG_DEVICE_CFG,
> +				   ADS112C14_DEVICE_CFG_CONV_MODE,
> +				   ADS112C14_DEVICE_CFG_CONV_MODE_SINGLE_SHOT);
> +		return ret;
> +	}
> +
> +	return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko