commit 4241665e6ea063a9c1d734de790121a71db763fc upstream.
A read operation is happening as follows:
a) Set sensor to forced mode
b) Sensor measures values and update data registers and sleeps again
c) Read data registers
In the current implementation the read operation happens immediately
after the sensor is set to forced mode so the sensor does not have
the time to update properly the registers. This leads to the following
2 problems:
1) The first ever value which is read by the register is always wrong
2) Every read operation, puts the register into forced mode and reads
the data that were calculated in the previous conversion.
This behaviour was tested in 2 ways:
1) The internal meas_status_0 register was read before and after every
read operation in order to verify that the data were ready even before
the register was set to forced mode and also to check that after the
forced mode was set the new data were not yet ready.
2) Physically changing the temperature and measuring the temperature
This commit adds the waiting time in between the set of the forced mode
and the read of the data. The function is taken from the Bosch BME68x
Sensor API [1].
[1]: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L490
Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor")
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://lore.kernel.org/r/20240606212313.207550-5-vassilisamir@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fdd478c3ae98c3f13628e110dce9b6cfb0d9b3c8 upstream.
There are cases in the compensate functions of the driver that
there could be overflows of variables due to bit shifting ops.
These implications were initially discussed here [1] and they
were mentioned in log message of Commit 1b3bd8592780 ("iio:
chemical: Add support for Bosch BME680 sensor").
[1]: https://lore.kernel.org/linux-iio/20180728114028.3c1bbe81@archlinux/
Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor")
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://lore.kernel.org/r/20240606212313.207550-4-vassilisamir@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b47c0fee73a810c4503c4a94ea34858a1d865bba upstream.
According to the BME68x Sensor API [1], the h6 calibration
data variable should be an unsigned integer of size 8.
[1]: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x_defs.h#L789
Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor")
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://lore.kernel.org/r/20240606212313.207550-3-vassilisamir@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ae1f7b93b52095be6776d0f34957b4f35dda44d9 upstream.
The IIO standard units are measured in kPa while the driver
is using hPa.
Apart from checking the userspace value itself, it is mentioned also
in the Bosch API [1] that the pressure value is in Pascal.
[1]: https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x_defs.h#L742
Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor")
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Link: https://lore.kernel.org/r/20240606212313.207550-2-vassilisamir@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
