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

Antoniu Miclaus
2025-10-07T11:15:59Z

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