This is a note to let you know that I've just added the patch titled
iio: adc: ad7780: Fix IRQ flag
to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From e081102f3077aa716974ccebec97003c890d5641 Mon Sep 17 00:00:00 2001
From: Alexandru Tachici alexandru.tachici@analog.com Date: Mon, 6 Sep 2021 09:56:29 +0300 Subject: iio: adc: ad7780: Fix IRQ flag
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 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 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@analog.com Cc: Stable@vger.kernel.org Link: https://lore.kernel.org/r/20210906065630.16325-3-alexandru.tachici@analog.co... Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- 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) \