Normally a syscall would check the current privilege level and then
decide to go to _impl_<syscall> directly or go through a
_handler_<syscall>.
__ZEPHYR_SUPERVISOR__ is a compiler optimization flag which will
make all the system calls from the driver files directly link
to the _impl_<syscall>. Thereby reducing the overhead of checking the
privileges.
In the previous implementation all the source files would be compiled
by zephyr_source() rule. This means that zephyr_* is a catchall CMake
library for source files that can be built purely with the include
paths, defines, and other compiler flags that all zephyr source
files uses. This states that adding one extra compiler flag for only
one complete directory would fail.
This limitation can be overcome by using zephyr_libray* APIs. This
creates a library for the required directories and it also supports
directory level properties.
Hence we use zephyr_library* to create a new library with
macro _ZEPHYR_SUPERVISOR_ for the optimization.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
The arithmetic performed on the CO2 and VOC measurements is pointless as
the units of the sensor already match those of the API, furthermore the
multiplication will overflow the u32_t with CO2 or VOC readings greater
than 4294 ppm or ppb. This CO2 concentration is achievable by breathing
at the sensor.
Signed-off-by: Aapo Vienamo <aapo.vienamo@iki.fi>
A condition is added to the Kconfig file to disable config options which
will be supplied from the dts.
Signed-off-by: Aapo Vienamo <aapo.vienamo@iki.fi>
Add support for AMS CCS811 Digital Gas Sensor for monitoring
indoor air quality. This sensor reports the following parameters:
1. Co2 concentration
2. VOC concentration
3. Sensor voltage
4. Sensor current
This driver only supports polling mode as of now.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Adithya Baglody