iio: adc: ad4080: fix chip identification

commit b66cddc upstream.

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: 6b31ba1 ("iio: adc: ad4080: add driver support")
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: amiclaus

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 +459,12 @@ 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,
+			       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);