void Clock_exit(void) { /* Set the decrementer to the maximum value */ ppc_set_decrementer_register( PPC_CLOCK_DECREMENTER_MAX); /* Use default clock handler */ ppc_clock_tick = ppc_clock_no_tick; }
static void t32mppc_clock_initialize(void) { uint64_t frequency = bsp_time_base_frequency / 10; uint32_t us_per_tick = rtems_configuration_get_microseconds_per_tick(); uint32_t interval = (uint32_t) ((frequency * us_per_tick) / 1000000); PPC_SET_SPECIAL_PURPOSE_REGISTER(BOOKE_DECAR, interval - 1); PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS( BOOKE_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE ); ppc_set_decrementer_register(interval - 1); t32mppc_clock_tc.tc_get_timecount = t32mppc_clock_get_timecount; t32mppc_clock_tc.tc_counter_mask = 0xffffffff; t32mppc_clock_tc.tc_frequency = bsp_time_base_frequency; t32mppc_clock_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER; rtems_timecounter_install(&t32mppc_clock_tc); }
static int ppc_clock_exception_handler( BSP_Exception_frame *frame, unsigned number ) { uint32_t delta = ppc_clock_decrementer_value; uint32_t next = ppc_clock_next_time_base; uint32_t dec = 0; uint32_t now = 0; uint32_t msr = 0; do { /* Increment clock ticks */ Clock_driver_ticks += 1; /* Enable external exceptions */ msr = ppc_external_exceptions_enable(); /* Call clock ticker */ ppc_clock_tick(); /* Restore machine state */ ppc_external_exceptions_disable( msr); /* Next time base */ next += delta; /* Current time */ now = ppc_time_base(); /* New decrementer value */ dec = next - now; } while (dec > delta); /* Set decrementer */ ppc_set_decrementer_register( dec); /* Expected next time base */ ppc_clock_next_time_base = next; return 0; }
/* Default decrementer exception handler */ static int mpc83xx_decrementer_exception_handler( BSP_Exception_frame *frame, unsigned number) { ppc_set_decrementer_register(UINT32_MAX); return 0; }
rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_device_minor_number minor, void *arg) { /* Current CPU type */ ppc_cpu_id_t cpu_type = get_ppc_cpu_type(); /* Make major/minor available to others such as shared memory driver */ rtems_clock_major = major; rtems_clock_minor = minor; /* * Set default ticker. * * The function rtems_clock_tick() returns a status code. This value * will be discarded since the RTEMS documentation claims that it is * always successful. */ ppc_clock_tick = (void (*)(void)) rtems_clock_tick; /* Set the decrementer to the maximum value */ ppc_set_decrementer_register( PPC_CLOCK_DECREMENTER_MAX); /* Decrementer value */ ppc_clock_decrementer_value = bsp_clicks_per_usec * rtems_configuration_get_microseconds_per_tick() - 1; /* Check decrementer value */ if (ppc_clock_decrementer_value == 0) { ppc_clock_decrementer_value = PPC_CLOCK_DECREMENTER_MAX; RTEMS_SYSLOG_ERROR( "decrementer value would be zero, will be set to maximum value instead\n"); } /* Set the nanoseconds since last tick handler */ rtems_clock_set_nanoseconds_extension( ppc_clock_nanoseconds_since_last_tick); if (ppc_cpu_is_bookE()) { /* Set decrementer auto-reload value */ PPC_SET_SPECIAL_PURPOSE_REGISTER( BOOKE_DECAR, ppc_clock_decrementer_value); /* Install exception handler */ ppc_exc_set_handler( ASM_BOOKE_DEC_VECTOR, ppc_clock_exception_handler_booke); /* Enable decrementer and auto-reload */ PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS( BOOKE_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE); } else if (cpu_type == PPC_e300c2 || cpu_type == PPC_e300c3) { /* TODO: Not tested for e300c2 */ /* Enable auto-reload */ PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS( HID0, 0x00000040); /* Install exception handler */ ppc_exc_set_handler( ASM_DEC_VECTOR, ppc_clock_exception_handler_e300); } else { /* Here the decrementer value is actually the interval */ ++ppc_clock_decrementer_value; /* Initialize next time base */ ppc_clock_next_time_base = ppc_time_base() + ppc_clock_decrementer_value; /* Install exception handler */ ppc_exc_set_handler( ASM_DEC_VECTOR, ppc_clock_exception_handler_first); } /* Set the decrementer value */ ppc_set_decrementer_register( ppc_clock_decrementer_value); return RTEMS_SUCCESSFUL; }
rtems_device_driver Clock_initialize( rtems_device_major_number major, rtems_device_minor_number minor, void *arg ) { uint64_t frequency = bsp_time_base_frequency; uint64_t us_per_tick = rtems_configuration_get_microseconds_per_tick(); uint32_t interval = (uint32_t) ((frequency * us_per_tick) / 1000000); /* * Set default ticker. */ ppc_clock_tick = rtems_timecounter_tick; if (ppc_cpu_is_bookE() != PPC_BOOKE_405) { /* Decrementer value */ ppc_clock_decrementer_value = interval - 1; /* Check decrementer value */ if (ppc_clock_decrementer_value == 0) { ppc_clock_decrementer_value = PPC_CLOCK_DECREMENTER_MAX; RTEMS_SYSLOG_ERROR( "decrementer value would be zero, will be set to maximum value instead\n"); } if (ppc_cpu_is_bookE()) { /* Set decrementer auto-reload value */ PPC_SET_SPECIAL_PURPOSE_REGISTER( BOOKE_DECAR, ppc_clock_decrementer_value); /* Install exception handler */ ppc_exc_set_handler( ASM_BOOKE_DEC_VECTOR, ppc_clock_exception_handler_booke); /* Enable decrementer and auto-reload */ PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS( BOOKE_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE); } else { /* Here the decrementer value is actually the interval */ ++ppc_clock_decrementer_value; /* Initialize next time base */ ppc_clock_next_time_base = ppc_time_base() + ppc_clock_decrementer_value; /* Install exception handler */ ppc_exc_set_handler( ASM_DEC_VECTOR, ppc_clock_exception_handler_first); } /* Set the decrementer value */ ppc_set_decrementer_register( ppc_clock_decrementer_value); } else { /* PIT interval value */ ppc_clock_decrementer_value = interval; /* Install exception handler */ ppc_exc_set_handler(ASM_BOOKE_DEC_VECTOR, ppc_clock_exception_handler_ppc405); /* Enable PIT and auto-reload */ PPC_SET_SPECIAL_PURPOSE_REGISTER_BITS(PPC405_TCR, BOOKE_TCR_DIE | BOOKE_TCR_ARE); /* Set PIT auto-reload and initial value */ PPC_SET_SPECIAL_PURPOSE_REGISTER(PPC405_PIT, interval); } /* Install timecounter */ ppc_tc.tc_get_timecount = ppc_get_timecount; ppc_tc.tc_counter_mask = 0xffffffff; ppc_tc.tc_frequency = frequency; ppc_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER; rtems_timecounter_install(&ppc_tc); return RTEMS_SUCCESSFUL; }