Re: [PATCH v4 07/13] iio: adc: ad4134: Support buffered data read

[Andy Shevchenko]

On Tue, Oct 06, 2026 at 03:17:56PM -0300, Marcelo Schmitt wrote:
> Enable users to run buffered data captures triggered by IIO trigger device.
> Add an IIO timestamp channel so each data scan is provided with measurement
> time information. Require single-read operations to be in IIO device direct
> access mode to prevent buffered and single-shot data captures to disrupt
> each other.

...

> +static irqreturn_t ad4134_trigger_handler(int irq, void *p)
> +{
> +	IIO_DECLARE_BUFFER_WITH_TS(u32, channels, AD4134_NUM_CHANNELS) = { };
> +	unsigned int chan_bytes = BITS_TO_BYTES(AD4134_CHAN_PRECISION_BITS);
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct ad4134_state *st = iio_priv(indio_dev);
> +	struct spi_transfer xfer = {
> +		.rx_buf = st->rx_buf,
> +		.cs_off = true,
> +		.len = chan_bytes * AD4134_NUM_CHANNELS,
> +	};
> +	int ret;
> +
> +	gpiod_set_value_cansleep(st->odr_gpio, 1);
> +	fsleep(1);
> +	gpiod_set_value_cansleep(st->odr_gpio, 0);
> +
> +	/* Run enough DCLK cycles to match the data frame length. */
> +	ret = spi_sync_transfer(st->spi, &xfer, 1);
> +	if (ret)
> +		goto out;

> +	for (int ch = 0, i = 0; ch < AD4134_NUM_CHANNELS; ch++) {
> +		if (!test_bit(ch, indio_dev->active_scan_mask))
> +			continue;

for_each_set_bit() ?

> +		channels[i++] = get_unaligned_be24(&st->rx_buf[ch * chan_bytes]);
> +	}
> +
> +	iio_push_to_buffers_with_ts(indio_dev, channels, sizeof(channels),
> +				    pf->timestamp);
> +
> +out:
> +	iio_trigger_notify_done(indio_dev->trig);
> +	return IRQ_HANDLED;
> +}

-- 
With Best Regards,
Andy Shevchenko