Re: [PATCH v2 1/6] iio: adc: ad4080: fix chip identification
From: Nuno Sá <hidden>
Date: 2025-09-30 12:35:19
Also in:
linux-iio, lkml
Hi Antoniu, I think that for a series like this you should include a cover letter... On Tue, 2025-09-30 at 10:32 +0000, Antoniu Miclaus wrote:
quoted hunk ↗ jump to hunk
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 v2: - add the chip id handling into a separate commit. - use regmap_bulk_read. drivers/iio/adc/ad4080.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/iio/adc/ad4080.c b/drivers/iio/adc/ad4080.c index 6e61787ed321..b80560aebe2d 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@@ -458,10 +458,11 @@ 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, 2); if (ret) return ret; + id = get_unaligned_le16(&id);
Being id an 'unsigned int' I'm not really sure the above will work on big endian machines as we should only populate the 2 MSB, right? But independent of that, id is only being used in here so I would use proper __le16 (and u16) and le16_to_cpu(). - Nuno Sá
if (id != AD4080_CHIP_ID) dev_info(dev, "Unrecognized CHIP_ID 0x%X\n", id);