ktime accessors

Device drivers can read the current time using ktime_get() and the many related functions declared in linux/timekeeping.h. As a rule of thumb, using an accessor with a shorter name is preferred over one with a longer name if both are equally fit for a particular use case.

Basic ktime_t based interfaces

The recommended simplest form returns an opaque ktime_t, with variants that return time for different clock references:

nanosecond, timespec64, and second output

For all of the above, there are variants that return the time in a different format depending on what is required by the user:

Coarse and fast_ns access

Some additional variants exist for more specialized cases:

Deprecated time interfaces

Older kernels used some other interfaces that are now being phased out but may appear in third-party drivers being ported here. In particular, all interfaces returning a 'struct timeval' or 'struct timespec' have been replaced because the tv_sec member overflows in year 2038 on 32-bit architectures. These are the recommended replacements: