On Mon, 6 Sep 2021 09:56:29 +0300
<alexandru.tachici@xxxxxxxxxx> wrote:
> From: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
>
> Correct IRQ flag here is falling.
>
> 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 imediately 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 AD7780 datasheet: " The DOUT/Figure 22 RDY falling edge
> can be used as an interrupt to a processor"
>
> Fixes: da4d3d6bb9f6 ("iio: adc: ad-sigma-delta: Allow custom IRQ flags")
> Signed-off-by: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
Applied and marked for stable.
Thanks,
Jonathan
> ---
> drivers/iio/adc/ad7780.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/ad7780.c b/drivers/iio/adc/ad7780.c
> index 42bb952f4738..b6e8c8abf6f4 100644
> --- a/drivers/iio/adc/ad7780.c
> +++ b/drivers/iio/adc/ad7780.c
> @@ -203,7 +203,7 @@ static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
> .set_mode = ad7780_set_mode,
> .postprocess_sample = ad7780_postprocess_sample,
> .has_registers = false,
> - .irq_flags = IRQF_TRIGGER_LOW,
> + .irq_flags = IRQF_TRIGGER_FALLING,
> };
>
> #define _AD7780_CHANNEL(_bits, _wordsize, _mask_all) \
