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[PATCH v3 1/6] iio: adc: ad4080: fix chip identification

Antoniu Miclaus posted 6 patches 4 months ago
[PATCH v3 1/6] iio: adc: ad4080: fix chip identification
Posted by Antoniu Miclaus 4 months ago 
Fix AD4080 chip identification by using the correct 16-bit product ID
(0x0050) instead of GENMASK(2, 0). Update the chip reading logic to
use regmap_bulk_read to read both PRODUCT_ID_L and PRODUCT_ID_H
registers and combine them into a 16-bit value.

The original implementation was incorrectly reading only 3 bits,
which would not correctly identify the AD4080 chip.

Fixes: 6b31ba1811b6 ("iio: adc: ad4080: add driver support")
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
changes in v3:
 - use le16_to_cpu to convert the read little-endian value to CPU endianness
 drivers/iio/adc/ad4080.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/ad4080.c b/drivers/iio/adc/ad4080.c
index 6e61787ed321..ae5a975a47a5 100644
--- a/drivers/iio/adc/ad4080.c
+++ b/drivers/iio/adc/ad4080.c
@@ -125,7 +125,7 @@
 
 /* Miscellaneous Definitions */
 #define AD4080_SPI_READ						BIT(7)
-#define AD4080_CHIP_ID						GENMASK(2, 0)
+#define AD4080_CHIP_ID						0x0050
 
 #define AD4080_LVDS_CNV_CLK_CNT_MAX				7
 
@@ -445,7 +445,8 @@ static int ad4080_setup(struct iio_dev *indio_dev)
 {
 	struct ad4080_state *st = iio_priv(indio_dev);
 	struct device *dev = regmap_get_device(st->regmap);
-	unsigned int id;
+	__le16 id_le;
+	u16 id;
 	int ret;
 
 	ret = regmap_write(st->regmap, AD4080_REG_INTERFACE_CONFIG_A,
@@ -458,10 +459,11 @@ static int ad4080_setup(struct iio_dev *indio_dev)
 	if (ret)
 		return ret;
 
-	ret = regmap_read(st->regmap, AD4080_REG_CHIP_TYPE, &id);
+	ret = regmap_bulk_read(st->regmap, AD4080_REG_PRODUCT_ID_L, &id_le, 2);
 	if (ret)
 		return ret;
 
+	id = le16_to_cpu(id_le);
 	if (id != AD4080_CHIP_ID)
 		dev_info(dev, "Unrecognized CHIP_ID 0x%X\n", id);
 
-- 
2.43.0
Re: [PATCH v3 1/6] iio: adc: ad4080: fix chip identification
Posted by Nuno Sá 4 months ago 
On Tue, 2025-10-07 at 11:15 +0000, Antoniu Miclaus wrote:
> Fix AD4080 chip identification by using the correct 16-bit product ID
> (0x0050) instead of GENMASK(2, 0). Update the chip reading logic to
> use regmap_bulk_read to read both PRODUCT_ID_L and PRODUCT_ID_H
> registers and combine them into a 16-bit value.
> 
> The original implementation was incorrectly reading only 3 bits,
> which would not correctly identify the AD4080 chip.
> 
> Fixes: 6b31ba1811b6 ("iio: adc: ad4080: add driver support")
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---

Small nitpick below that Jonathan might tweak if he thinks it's worth it.
Anyways,

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

> changes in v3:
>  - use le16_to_cpu to convert the read little-endian value to CPU endianness
>  drivers/iio/adc/ad4080.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad4080.c b/drivers/iio/adc/ad4080.c
> index 6e61787ed321..ae5a975a47a5 100644
> --- a/drivers/iio/adc/ad4080.c
> +++ b/drivers/iio/adc/ad4080.c
> @@ -125,7 +125,7 @@
>  
>  /* Miscellaneous Definitions */
>  #define
> AD4080_SPI_READ						BIT(7)
> -#define AD4080_CHIP_ID						GENMASK(2, 0)
> +#define AD4080_CHIP_ID						0x0050
>  
>  #define AD4080_LVDS_CNV_CLK_CNT_MAX				7
>  
> @@ -445,7 +445,8 @@ static int ad4080_setup(struct iio_dev *indio_dev)
>  {
>  	struct ad4080_state *st = iio_priv(indio_dev);
>  	struct device *dev = regmap_get_device(st->regmap);
> -	unsigned int id;
> +	__le16 id_le;
> +	u16 id;
>  	int ret;
>  
>  	ret = regmap_write(st->regmap, AD4080_REG_INTERFACE_CONFIG_A,
> @@ -458,10 +459,11 @@ static int ad4080_setup(struct iio_dev *indio_dev)
>  	if (ret)
>  		return ret;
>  
> -	ret = regmap_read(st->regmap, AD4080_REG_CHIP_TYPE, &id);
> +	ret = regmap_bulk_read(st->regmap, AD4080_REG_PRODUCT_ID_L, &id_le,
> 2);

sizeof(id_le)

>  	if (ret)
>  		return ret;
>  
> +	id = le16_to_cpu(id_le);
>  	if (id != AD4080_CHIP_ID)
>  		dev_info(dev, "Unrecognized CHIP_ID 0x%X\n", id);
>  
Re: [PATCH v3 1/6] iio: adc: ad4080: fix chip identification
Posted by Jonathan Cameron 3 months, 4 weeks ago 
On Tue, 07 Oct 2025 15:41:02 +0100
Nuno Sá <noname.nuno@gmail.com> wrote:

> On Tue, 2025-10-07 at 11:15 +0000, Antoniu Miclaus wrote:
> > Fix AD4080 chip identification by using the correct 16-bit product ID
> > (0x0050) instead of GENMASK(2, 0). Update the chip reading logic to
> > use regmap_bulk_read to read both PRODUCT_ID_L and PRODUCT_ID_H
> > registers and combine them into a 16-bit value.
> > 
> > The original implementation was incorrectly reading only 3 bits,
> > which would not correctly identify the AD4080 chip.
> > 
> > Fixes: 6b31ba1811b6 ("iio: adc: ad4080: add driver support")
> > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> > ---  
> 
> Small nitpick below that Jonathan might tweak if he thinks it's worth it.
> Anyways,
> 
> Reviewed-by: Nuno Sá <nuno.sa@analog.com>

I'll tidy that up.

I'm currently taking a possibly controversial route with this patch.

Given I think we just get a false warning message without it, I'm going
to assume this isn't critical and queue it up for next merge window.
The advantage is I don't have to deal with tracking this patch going upstream
before I can apply the others in the series...

Shout if you'd prefer the harder route that gets this upstream faster.

Jonathan

> 
> > changes in v3:
> >  - use le16_to_cpu to convert the read little-endian value to CPU endianness
> >  drivers/iio/adc/ad4080.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/iio/adc/ad4080.c b/drivers/iio/adc/ad4080.c
> > index 6e61787ed321..ae5a975a47a5 100644
> > --- a/drivers/iio/adc/ad4080.c
> > +++ b/drivers/iio/adc/ad4080.c
> > @@ -125,7 +125,7 @@
> >  
> >  /* Miscellaneous Definitions */
> >  #define
> > AD4080_SPI_READ						BIT(7)
> > -#define AD4080_CHIP_ID						GENMASK(2, 0)
> > +#define AD4080_CHIP_ID						0x0050
> >  
> >  #define AD4080_LVDS_CNV_CLK_CNT_MAX				7
> >  
> > @@ -445,7 +445,8 @@ static int ad4080_setup(struct iio_dev *indio_dev)
> >  {
> >  	struct ad4080_state *st = iio_priv(indio_dev);
> >  	struct device *dev = regmap_get_device(st->regmap);
> > -	unsigned int id;
> > +	__le16 id_le;
> > +	u16 id;
> >  	int ret;
> >  
> >  	ret = regmap_write(st->regmap, AD4080_REG_INTERFACE_CONFIG_A,
> > @@ -458,10 +459,11 @@ static int ad4080_setup(struct iio_dev *indio_dev)
> >  	if (ret)
> >  		return ret;
> >  
> > -	ret = regmap_read(st->regmap, AD4080_REG_CHIP_TYPE, &id);
> > +	ret = regmap_bulk_read(st->regmap, AD4080_REG_PRODUCT_ID_L, &id_le,
> > 2);  
> 
> sizeof(id_le)
> 
> >  	if (ret)
> >  		return ret;
> >  
> > +	id = le16_to_cpu(id_le);
> >  	if (id != AD4080_CHIP_ID)
> >  		dev_info(dev, "Unrecognized CHIP_ID 0x%X\n", id);
> >  

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