diff options
Diffstat (limited to 'cpukit/score/cpu/powerpc/rtems/score/cpu.h')
| -rw-r--r-- | cpukit/score/cpu/powerpc/rtems/score/cpu.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/cpukit/score/cpu/powerpc/rtems/score/cpu.h b/cpukit/score/cpu/powerpc/rtems/score/cpu.h index 57fac52df3..3c561c0ae1 100644 --- a/cpukit/score/cpu/powerpc/rtems/score/cpu.h +++ b/cpukit/score/cpu/powerpc/rtems/score/cpu.h @@ -115,5 +115,35 @@ static inline uint32_t CPU_swap_u32( #endif /* ASM */ +#ifndef /* ASM */ +/* + * Simple spin delay in microsecond units for device drivers. + * This is very dependent on the clock speed of the target. + */ + +#define CPU_Get_timebase_low( _value ) \ + asm volatile( "mftb %0" : "=r" (_value) ) + +#define rtems_bsp_delay( _microseconds ) \ + do { \ + uint32_t start, ticks, now; \ + CPU_Get_timebase_low( start ) ; \ + ticks = (_microseconds) * rtems_cpu_configuration_get_clicks_per_usec(); \ + do \ + CPU_Get_timebase_low( now ) ; \ + while (now - start < ticks); \ + } while (0) + +#define rtems_bsp_delay_in_bus_cycles( _cycles ) \ + do { \ + uint32_t start, now; \ + CPU_Get_timebase_low( start ); \ + do \ + CPU_Get_timebase_low( now ); \ + while (now - start < (_cycles)); \ + } while (0) + +#endif /* ASM */ + #endif /* _RTEMS_SCORE_CPU_H */ |