Commit 63275731 authored by David Lechner's avatar David Lechner Committed by Jonathan Cameron
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iio: adc: ad7380: fix SPI offload trigger rate 



Add a special case to double the SPI offload trigger rate when all
channels of a single-ended chip are enabled in a buffered read.

The single-ended chips in the AD738x family can only do simultaneous
sampling of half their channels and have a multiplexer to allow reading
the other half. To comply with the IIO definition of sampling_frequency,
we need to trigger twice as often when the sequencer is enabled to so
that both banks can be read in a single sample period.

Fixes: bbeaec81 ("iio: ad7380: add support for SPI offload")
Signed-off-by: default avatarDavid Lechner <dlechner@baylibre.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 9b45744b

drivers/iio/adc/ad7380.c

+8 −0
Original line number Diff line number Diff line
@@ -1227,6 +1227,14 @@ static int ad7380_offload_buffer_postenable(struct iio_dev *indio_dev) 
	if (ret)

		return ret;



	/*

	 * When the sequencer is required to read all channels, we need to

	 * trigger twice per sample period in order to read one complete set

	 * of samples.

	 */

	if (st->seq)

		config.periodic.frequency_hz *= 2;



	ret = spi_offload_trigger_enable(st->offload, st->offload_trigger, &config);

	if (ret)

		spi_unoptimize_message(&st->offload_msg);