diff mbox series

[v2,3/3] iio: adc: ad7793: Fix IRQ flag

Message ID 20210906065630.16325-4-alexandru.tachici@analog.com (mailing list archive)
State Accepted
Headers show
Series iio: adc: Fix flags in sigma-delta drivers | expand

Commit Message

Alexandru Tachici Sept. 6, 2021, 6:56 a.m. UTC 
From: Alexandru Tachici <alexandru.tachici@analog.com>

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 AD7793 datasheet: " The DOUT/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>
---
 drivers/iio/adc/ad7793.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jonathan Cameron Sept. 11, 2021, 5:46 p.m. UTC | #1 
On Mon, 6 Sep 2021 09:56:30 +0300
<alexandru.tachici@analog.com> wrote:

> From: Alexandru Tachici <alexandru.tachici@analog.com>
> 
> 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 AD7793 datasheet: " The DOUT/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>
Applied to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/ad7793.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
> index ef3e2d3ecb0c..0e7ab3fb072a 100644
> --- a/drivers/iio/adc/ad7793.c
> +++ b/drivers/iio/adc/ad7793.c
> @@ -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] = {
diff mbox series

Patch

diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
index ef3e2d3ecb0c..0e7ab3fb072a 100644
--- a/drivers/iio/adc/ad7793.c
+++ b/drivers/iio/adc/ad7793.c
@@ -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] = {