[PATCH] iio: adc: ad4080: enable address ascension for chip identification

[Antoniu Miclaus <antoniu.miclaus@analog.com>]

The two byte bulk read at AD4080_REG_PRODUCT_ID_L expects PRODUCT_ID_L
followed by PRODUCT_ID_H. After a software reset the AD408x defaults to
descending address mode, so the second byte comes from CHIP_TYPE (0x03)
instead. CHIP_TYPE reads 0x07 on all AD408x parts, so an AD4080 reports
0x0750 rather than 0x0050 and every part logs "Unrecognized CHIP_ID".

Set ADDR_ASC along with SDO_ENABLE before the read. This is the only
multi byte transfer in the driver, so no other access is affected.

Fixes: b66cddc8be72 ("iio: adc: ad4080: fix chip identification")
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
 drivers/iio/adc/ad4080.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad4080.c b/drivers/iio/adc/ad4080.c
index 4843ecdd91a8..4ed82aa42400 100644
--- a/drivers/iio/adc/ad4080.c
+++ b/drivers/iio/adc/ad4080.c
@@ -710,7 +710,8 @@ static int ad4080_setup_channel(struct ad4080_state *st, unsigned int ch)
 		return ret;
 
 	ret = regmap_write(st->regmap[ch], AD4080_REG_INTERFACE_CONFIG_A,
-			   AD4080_INTERFACE_CONFIG_A_SDO_ENABLE);
+			   AD4080_INTERFACE_CONFIG_A_SDO_ENABLE |
+			   AD4080_INTERFACE_CONFIG_A_ADDR_ASC);
 	if (ret)
 		return ret;
 

base-commit: dceba8e581e3e8f475da0efbd7a73f3d9524ddd2
-- 
2.43.0