[PATCH] iio: adc: nxp-sar-adc: use field_get() for EOC bit check

[PATCH] iio: adc: nxp-sar-adc: use field_get() for EOC bit check

[Piyush Patle]

The driver uses FIELD_GET() for constant-mask fields but falls back
to a raw bit test for the per-channel EOC bit, as the mask depends
on the runtime channel index. A TODO notes that this should switch
to field_get() when available.

Use field_get() here now that runtime-mask support exists, and drop
the obsolete TODO. Since NXP_SAR_ADC_EOC_CH(c) is BIT(c), the
resulting !-test is semantically identical.

No functional change.

Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>
---
 drivers/iio/adc/nxp-sar-adc.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/iio/adc/nxp-sar-adc.c b/drivers/iio/adc/nxp-sar-adc.c
index 58103bf16aff..d6c2a0d50bb4 100644
--- a/drivers/iio/adc/nxp-sar-adc.c
+++ b/drivers/iio/adc/nxp-sar-adc.c
@@ -316,11 +316,7 @@ static int nxp_sar_adc_read_data(struct nxp_sar_adc *info, unsigned int chan)
 
 	ceocfr = readl(NXP_SAR_ADC_CEOCFR0(info->regs));
 
-	/*
-	 * FIELD_GET() can not be used here because EOC_CH is not constant.
-	 * TODO: Switch to field_get() when it will be available.
-	 */
-	if (!(NXP_SAR_ADC_EOC_CH(chan) & ceocfr))
+	if (!field_get(NXP_SAR_ADC_EOC_CH(chan), ceocfr))
 		return -EIO;
 
 	cdr = readl(NXP_SAR_ADC_CDR(info->regs, chan));
-- 
2.43.0

Re: [PATCH] iio: adc: nxp-sar-adc: use field_get() for EOC bit check

[David Lechner]

On 4/10/26 4:13 PM, Piyush Patle wrote:
> The driver uses FIELD_GET() for constant-mask fields but falls back
> to a raw bit test for the per-channel EOC bit, as the mask depends
> on the runtime channel index. A TODO notes that this should switch
> to field_get() when available.

Could drop this first paragraph, it is a bit redundant.

> 
> Use field_get() here now that runtime-mask support exists, and drop

We like for commit messages to start with the verb like this, so
this would be ideal for the first paragraph of the commit message.

> the obsolete TODO. Since NXP_SAR_ADC_EOC_CH(c) is BIT(c), the
> resulting !-test is semantically identical.
> 
> No functional change.
> 
> Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>
> ---
Reviewed-by: David Lechner <dlechner@baylibre.com>


And if you are interested in doing more like this, search the IIO
subsystem for __ffs. If it is used with << or >> then there is a
good chance it could be replaced with field_get() or field_prep().

Re: [PATCH] iio: adc: nxp-sar-adc: use field_get() for EOC bit check

[Piyush Patle]

> On 4/10/26 4:13 PM, Piyush Patle wrote:
> > The driver uses FIELD_GET() for constant-mask fields but falls back
> > to a raw bit test for the per-channel EOC bit, as the mask depends
> > on the runtime channel index. A TODO notes that this should switch
> > to field_get() when available.
>
> Could drop this first paragraph, it is a bit redundant.
>
> >
> > Use field_get() here now that runtime-mask support exists, and drop
>
> We like for commit messages to start with the verb like this, so
> this would be ideal for the first paragraph of the commit message.

I have addressed all your comments.

>
> > the obsolete TODO. Since NXP_SAR_ADC_EOC_CH(c) is BIT(c), the
> > resulting !-test is semantically identical.
> >
> > No functional change.
> >
> > Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>
> > ---
> Reviewed-by: David Lechner <dlechner@baylibre.com>
>

Thanks for the review. Sent v2!

>
> And if you are interested in doing more like this, search the IIO
> subsystem for __ffs. If it is used with << or >> then there is a
> good chance it could be replaced with field_get() or field_prep().
>

I'll also look for similar __ffs() patterns in IIO and convert them
to field_get()/field_prep() where appropriate.

Re: [PATCH] iio: adc: nxp-sar-adc: use field_get() for EOC bit check

[David Laight]

On Fri, 10 Apr 2026 16:26:05 -0500
David Lechner <dlechner@baylibre.com> wrote:

> On 4/10/26 4:13 PM, Piyush Patle wrote:
> > The driver uses FIELD_GET() for constant-mask fields but falls back
> > to a raw bit test for the per-channel EOC bit, as the mask depends
> > on the runtime channel index. A TODO notes that this should switch
> > to field_get() when available.  
> 
> Could drop this first paragraph, it is a bit redundant.
> 
> > 
> > Use field_get() here now that runtime-mask support exists, and drop  
> 
> We like for commit messages to start with the verb like this, so
> this would be ideal for the first paragraph of the commit message.
> 
> > the obsolete TODO. Since NXP_SAR_ADC_EOC_CH(c) is BIT(c), the
> > resulting !-test is semantically identical.
> > 
> > No functional change.
> > 
> > Signed-off-by: Piyush Patle <piyushpatle228@gmail.com>
> > ---  
> Reviewed-by: David Lechner <dlechner@baylibre.com>
> 
> 
> And if you are interested in doing more like this, search the IIO
> subsystem for __ffs. If it is used with << or >> then there is a
> good chance it could be replaced with field_get() or field_prep().
> 
> 

And likely make the code larger and slower :-)
At least run the bloat-o-meter.

	David