[PATCH] iio: gyro: mpu3050: fix sign of raw angular velocity readings
Cong Nguyen <[email protected]> Sun, 2 Aug 2026 13:55:40 +0700
| Newsgroups | org.kernel.vger.linux-iio,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
The MPU-3050 gyroscope output registers hold 16-bit two's complement
values; the angular velocity channels are declared with .sign = 's'.
When mpu3050_read_raw() handles IIO_CHAN_INFO_RAW it reads the register
via a big-endian regmap_bulk_read() and assigns it with:
*val = be16_to_cpu(raw_val);
be16_to_cpu() yields an unsigned 16-bit quantity, so negative rates
(bit 15 set) are reported to userspace as large positive integers
(e.g. -1 becomes 65535) instead of the correct negative value.
Cast to s16 before the assignment, matching the temperature channel a
few lines above which already handles the sign correctly.
Fixes: 3904b28efb2c ("iio: gyro: Add driver for the MPU-3050 gyroscope")
Cc: [email protected]
Assisted-by: Claude:claude-opus-4
Signed-off-by: Cong Nguyen <[email protected]>
---
drivers/iio/gyro/mpu3050-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
index d84e04e4b431..07c0f9011c63 100644
--- a/drivers/iio/gyro/mpu3050-core.c
+++ b/drivers/iio/gyro/mpu3050-core.c
@@ -356,7 +356,7 @@ static int mpu3050_read_raw(struct iio_dev *indio_dev,
goto out_read_raw_unlock;
}
- *val = be16_to_cpu(raw_val);
+ *val = (s16)be16_to_cpu(raw_val);
ret = IIO_VAL_INT;
goto out_read_raw_unlock;
--
2.25.1