iio: adc: ad7793: Fix IRQ flag

In Sigma-Delta devices the SDO line is also used as an interrupt.
Leaving IRQ on level instead of falling might trigger a sample read
when the IRQ is enabled, as the SDO line is already low. Not sure
if SDO line will always immediately go high in ad_sd_buffer_postenable
before the IRQ is enabled.

Also the datasheet seem to explicitly say the falling edge of the SDO
should be used as an interrupt:
>From the AD7793 datasheet: " The DOUT/RDY falling edge can be
used as an interrupt to a processor"

Fixes: da4d3d6bb9 ("iio: adc: ad-sigma-delta: Allow custom IRQ flags")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210906065630.16325-4-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Alexandru Tachici 2021-09-06 09:56:30 +03:00 committed by Jonathan Cameron
parent e081102f30
commit 1a913270e5

View File

@ -206,7 +206,7 @@ static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
.has_registers = true,
.addr_shift = 3,
.read_mask = BIT(6),
.irq_flags = IRQF_TRIGGER_LOW,
.irq_flags = IRQF_TRIGGER_FALLING,
};
static const struct ad_sd_calib_data ad7793_calib_arr[6] = {