src/system/kernel/arch/ppc/arch_real_time_clock.cpp

   1 /*
   2  * Copyright 2006, Ingo Weinhold <bonefish@cs.tu-berlin.de>.
   3  * All rights reserved. Distributed under the terms of the MIT License.
   4  */
   5
   6 #include <arch/real_time_clock.h>
   7
   8 #include <arch_platform.h>
   9 #include <boot/kernel_args.h>
  10 #include <real_time_data.h>
  11 #include <smp.h>
  12
  13
  14 static spinlock sSetArchDataLock;
  15
  16 status_t
  17 arch_rtc_init(kernel_args *args, struct real_time_data *data)
  18 {
  19         // init the platform RTC service
  20         status_t error = PPCPlatform::Default()->InitRTC(args, data);
  21         if (error != B_OK)
  22                 return error;
  23
  24         // init the arch specific part of the real_time_data
  25         data->arch_data.data[0].system_time_offset = 0;
  26         // cvFactor = 2^32 * 1000000 / tbFreq
  27         // => (tb * cvFactor) >> 32 = (tb * 2^32 * 1000000 / tbFreq) >> 32
  28         //    = tb / tbFreq * 1000000 = time in us
  29         data->arch_data.system_time_conversion_factor
  30                 = uint32((uint64(1) << 32) * 1000000
  31                         / args->arch_args.time_base_frequency);
  32         data->arch_data.version = 0;
  33
  34         // init spinlock
  35         B_INITIALIZE_SPINLOCK(&sSetArchDataLock);
  36
  37         // init system_time() conversion factor
  38         __ppc_setup_system_time(&data->arch_data.system_time_conversion_factor);
  39
  40         return B_OK;
  41 }
  42
  43
  44 uint32
  45 arch_rtc_get_hw_time(void)
  46 {
  47         return PPCPlatform::Default()->GetHardwareRTC();
  48 }
  49
  50
  51 void
  52 arch_rtc_set_hw_time(uint32 seconds)
  53 {
  54         PPCPlatform::Default()->SetHardwareRTC(seconds);
  55 }
  56
  57
  58 void
  59 arch_rtc_set_system_time_offset(struct real_time_data *data, bigtime_t offset)
  60 {
  61         cpu_status state = disable_interrupts();
  62         acquire_spinlock(&sSetArchDataLock);
  63
  64         int32 version = data->arch_data.version + 1;
  65         data->arch_data.data[version % 2].system_time_offset = offset;
  66         data->arch_data.version = version;
  67
  68         release_spinlock(&sSetArchDataLock);
  69         restore_interrupts(state);
  70 }
  71
  72
  73 bigtime_t
  74 arch_rtc_get_system_time_offset(struct real_time_data *data)
  75 {
  76         int32 version;
  77         bigtime_t offset;
  78         do {
  79                 version = data->arch_data.version;
  80                 offset = data->arch_data.data[version % 2].system_time_offset;
  81         } while (version != data->arch_data.version);
  82
  83         return offset;
  84 }