patch "iio: adc: ad7780: Fix IRQ flag" added to staging-linus

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 <[email protected]>
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:

can be used as an interrupt to a processor"

---
 drivers/iio/adc/ad7780.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 42bb952f4738..b6e8c8abf6f4 100644
@@ -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)		\

2.33.0