x52test used to assume that a positive return code indicated a signal
was received and a negative return code indicated an error in libx52.
However, libx52 was changed a while back to return only a positive error
code of type `libx52_error_code`.
This commit changes that assumption, so that:
* The first check is always against `LIBX52_SUCCESS`, to ensure that any
change in the enumeration won't break the rest of the code.
* Tests terminated by a signal return the negated value of the signal,
i.e. -15 is SIGTERM and -2 is SIGINT.
* Tests that fail within libx52 return a standard `libx52_error_code`.
* Error printing uses `libx52_strerror`.
Addresses #19.
x52test by default expects to run with an attached X52 unit. Since the
primary goal of the program is to test the hardware, it has embedded
delays to allow the user to verify the individual LEDs, MFD, brightness,
etc.
However, the complete test takes about 6 minutes. When using the stub
libusb library, the goal is to capture the requests, not verify it
against the hardware. In this case, the delays serve no useful purpose.
This change adds a nodelay flag, which is controlled by the presence of
a `NO_DELAY` environment variable, or the `LD_PRELOAD` environment
variable. As long as either of these variables are present in the
environment block, there will be no delays in the test execution.
- libx52_init returns the libx52_device in an output parameter and
returns a libx52_error_code
- Make all functions return libx52_error_code
- Update package version to indicate incompatible API change
nirenjan