iio: adc: xilinx-xadc: Fix sequencer mode in postdisable for dual mux

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xadc_postdisable() unconditionally sets the sequencer to continuous
mode. For dual external multiplexer configurations this is incorrect:
simultaneous sampling mode is required so that ADC-A samples through
the mux on VAUX[0-7] while ADC-B simultaneously samples through the
mux on VAUX[8-15]. In continuous mode only ADC-A is active, so
VAUX[8-15] channels return incorrect data.

Since postdisable is also called from xadc_probe() to set the initial
idle state, the wrong sequencer mode is active from the moment the
driver loads.

The preenable path already uses xadc_get_seq_mode() which returns
SIMULTANEOUS for dual mux. Fix postdisable to do the same.

Fixes: bdc8cda1d0 ("iio:adc: Add Xilinx XADC driver")
Cc: stable@vger.kernel.org
Signed-off-by: Christofer Jonason <christofer.jonason@guidelinegeo.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Salih Erim <salih.erim@amd.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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Christofer Jonason 2026-03-04 10:07:27 +01:00 • committed by Jonathan Cameron

parent 254f49634e

commit 852534744c

1 changed files with 9 additions and 2 deletions

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drivers/iio/adc/xilinx-xadc-core.c

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