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authorDmitry Osipenko <digetx@gmail.com>2021-04-23 05:09:59 +0300
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2021-05-10 14:01:48 +0100
commitf73c730774d88a14d7b60feee6d0e13570f99499 (patch)
tree3f9bb847fca6ded4db46132bfd6a46e1e3565640 /drivers/iio
parent7061803522ee7876df1ca18cdd1e1551f761352d (diff)
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iio: gyro: mpu3050: Fix reported temperature value
The raw temperature value is a 16-bit signed integer. The sign casting is missing in the code, which results in a wrong temperature reported by userspace tools, fix it. Cc: stable@vger.kernel.org Fixes: 3904b28efb2c ("iio: gyro: Add driver for the MPU-3050 gyroscope") Datasheet: https://www.cdiweb.com/datasheets/invensense/mpu-3000a.pdf Tested-by: Maxim Schwalm <maxim.schwalm@gmail.com> # Asus TF700T Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # Asus TF201 Reported-by: Svyatoslav Ryhel <clamor95@gmail.com> Reviewed-by: Andy Shevchenko <Andy.Shevchenko@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Acked-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com> Link: https://lore.kernel.org/r/20210423020959.5023-1-digetx@gmail.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/gyro/mpu3050-core.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
index ac90be03332a..f17a93519535 100644
--- a/drivers/iio/gyro/mpu3050-core.c
+++ b/drivers/iio/gyro/mpu3050-core.c
@@ -272,7 +272,16 @@ static int mpu3050_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_OFFSET:
switch (chan->type) {
case IIO_TEMP:
- /* The temperature scaling is (x+23000)/280 Celsius */
+ /*
+ * The temperature scaling is (x+23000)/280 Celsius
+ * for the "best fit straight line" temperature range
+ * of -30C..85C. The 23000 includes room temperature
+ * offset of +35C, 280 is the precision scale and x is
+ * the 16-bit signed integer reported by hardware.
+ *
+ * Temperature value itself represents temperature of
+ * the sensor die.
+ */
*val = 23000;
return IIO_VAL_INT;
default:
@@ -329,7 +338,7 @@ 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;