EmbeddedPkg/RealTimeClockRuntimeDxe/RealTimeClock.c

   1 /** @file
   2   Implement EFI RealTimeClock runtime services via RTC Lib.
   3
   4   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   5   Copyright (c) 2017, Linaro, Ltd. All rights reserved.<BR>
   6   Copyright (c) 2021, Ampere Computing LLC. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <PiDxe.h>
  13 #include <Library/DebugLib.h>
  14 #include <Library/RealTimeClockLib.h>
  15 #include <Library/TimeBaseLib.h>
  16 #include <Library/UefiLib.h>
  17 #include <Library/UefiBootServicesTableLib.h>
  18 #include <Library/UefiRuntimeLib.h>
  19 #include <Protocol/RealTimeClock.h>
  20
  21 EFI_HANDLE  mHandle = NULL;
  22
  23 //
  24 // These values can be set by SetTime () and need to be returned by GetTime ()
  25 // but cannot usually be kept by the RTC hardware, so we store them in a UEFI
  26 // variable instead.
  27 //
  28 typedef struct {
  29   INT16    TimeZone;
  30   UINT8    Daylight;
  31 } NON_VOLATILE_TIME_SETTINGS;
  32
  33 STATIC CONST CHAR16                mTimeSettingsVariableName[] = L"RtcTimeSettings";
  34 STATIC NON_VOLATILE_TIME_SETTINGS  mTimeSettings;
  35
  36 /**
  37   Returns the current time and date information, and the time-keeping capabilities
  38   of the hardware platform.
  39
  40   @param  Time                  A pointer to storage to receive a snapshot of the current time.
  41   @param  Capabilities          An optional pointer to a buffer to receive the real time clock
  42                                 device's capabilities.
  43
  44   @retval EFI_SUCCESS           The operation completed successfully.
  45   @retval EFI_INVALID_PARAMETER Time is NULL.
  46   @retval EFI_DEVICE_ERROR      The time could not be retrieved due to hardware error.
  47
  48 **/
  49 EFI_STATUS
  50 EFIAPI
  51 GetTime (
  52   OUT EFI_TIME               *Time,
  53   OUT EFI_TIME_CAPABILITIES  *Capabilities
  54   )
  55 {
  56   if (Time == NULL) {
  57     return EFI_INVALID_PARAMETER;
  58   }
  59
  60   //
  61   // Set these first so the RealTimeClockLib implementation
  62   // can override them based on its own settings.
  63   //
  64   Time->TimeZone = mTimeSettings.TimeZone;
  65   Time->Daylight = mTimeSettings.Daylight;
  66
  67   return LibGetTime (Time, Capabilities);
  68 }
  69
  70 /**
  71   Sets the current local time and date information.
  72
  73   @param  Time                  A pointer to the current time.
  74
  75   @retval EFI_SUCCESS           The operation completed successfully.
  76   @retval EFI_INVALID_PARAMETER A time field is out of range.
  77   @retval EFI_DEVICE_ERROR      The time could not be set due to hardware error.
  78
  79 **/
  80 EFI_STATUS
  81 EFIAPI
  82 SetTime (
  83   IN EFI_TIME  *Time
  84   )
  85 {
  86   EFI_STATUS  Status;
  87   BOOLEAN     TimeSettingsChanged;
  88
  89   if ((Time == NULL) || !IsTimeValid (Time)) {
  90     return EFI_INVALID_PARAMETER;
  91   }
  92
  93   TimeSettingsChanged = FALSE;
  94   if ((mTimeSettings.TimeZone != Time->TimeZone) ||
  95       (mTimeSettings.Daylight != Time->Daylight))
  96   {
  97     mTimeSettings.TimeZone = Time->TimeZone;
  98     mTimeSettings.Daylight = Time->Daylight;
  99     TimeSettingsChanged    = TRUE;
 100   }
 101
 102   Status = LibSetTime (Time);
 103   if (EFI_ERROR (Status)) {
 104     return Status;
 105   }
 106
 107   if (TimeSettingsChanged) {
 108     Status = EfiSetVariable (
 109                (CHAR16 *)mTimeSettingsVariableName,
 110                &gEfiCallerIdGuid,
 111                EFI_VARIABLE_NON_VOLATILE |
 112                EFI_VARIABLE_BOOTSERVICE_ACCESS |
 113                EFI_VARIABLE_RUNTIME_ACCESS,
 114                sizeof (mTimeSettings),
 115                (VOID *)&mTimeSettings
 116                );
 117     if (EFI_ERROR (Status)) {
 118       return EFI_DEVICE_ERROR;
 119     }
 120   }
 121
 122   return EFI_SUCCESS;
 123 }
 124
 125 /**
 126   Returns the current wakeup alarm clock setting.
 127
 128   @param  Enabled               Indicates if the alarm is currently enabled or disabled.
 129   @param  Pending               Indicates if the alarm signal is pending and requires acknowledgement.
 130   @param  Time                  The current alarm setting.
 131
 132   @retval EFI_SUCCESS           The alarm settings were returned.
 133   @retval EFI_INVALID_PARAMETER Any parameter is NULL.
 134   @retval EFI_DEVICE_ERROR      The wakeup time could not be retrieved due to a hardware error.
 135
 136 **/
 137 EFI_STATUS
 138 EFIAPI
 139 GetWakeupTime (
 140   OUT BOOLEAN   *Enabled,
 141   OUT BOOLEAN   *Pending,
 142   OUT EFI_TIME  *Time
 143   )
 144 {
 145   if ((Time == NULL) || (Enabled == NULL) || (Pending == NULL)) {
 146     return EFI_INVALID_PARAMETER;
 147   }
 148
 149   //
 150   // Set these first so the RealTimeClockLib implementation
 151   // can override them based on its own settings.
 152   //
 153   Time->TimeZone = mTimeSettings.TimeZone;
 154   Time->Daylight = mTimeSettings.Daylight;
 155
 156   return LibGetWakeupTime (Enabled, Pending, Time);
 157 }
 158
 159 /**
 160   Sets the system wakeup alarm clock time.
 161
 162   @param  Enabled               Enable or disable the wakeup alarm.
 163   @param  Time                  If Enable is TRUE, the time to set the wakeup alarm for.
 164
 165   @retval EFI_SUCCESS           If Enable is TRUE, then the wakeup alarm was enabled. If
 166                                 Enable is FALSE, then the wakeup alarm was disabled.
 167   @retval EFI_INVALID_PARAMETER A time field is out of range.
 168   @retval EFI_DEVICE_ERROR      The wakeup time could not be set due to a hardware error.
 169   @retval EFI_UNSUPPORTED       A wakeup timer is not supported on this platform.
 170
 171 **/
 172 EFI_STATUS
 173 EFIAPI
 174 SetWakeupTime (
 175   IN BOOLEAN    Enabled,
 176   OUT EFI_TIME  *Time
 177   )
 178 {
 179   return LibSetWakeupTime (Enabled, Time);
 180 }
 181
 182 /**
 183   This is the declaration of an EFI image entry point. This can be the entry point to an application
 184   written to this specification, an EFI boot service driver, or an EFI runtime driver.
 185
 186   @param  ImageHandle           Handle that identifies the loaded image.
 187   @param  SystemTable           System Table for this image.
 188
 189   @retval EFI_SUCCESS           The operation completed successfully.
 190
 191 **/
 192 EFI_STATUS
 193 EFIAPI
 194 InitializeRealTimeClock (
 195   IN EFI_HANDLE        ImageHandle,
 196   IN EFI_SYSTEM_TABLE  *SystemTable
 197   )
 198 {
 199   EFI_STATUS  Status;
 200   UINTN       Size;
 201
 202   Status = LibRtcInitialize (ImageHandle, SystemTable);
 203   if (EFI_ERROR (Status)) {
 204     return Status;
 205   }
 206
 207   Size   = sizeof (mTimeSettings);
 208   Status = EfiGetVariable (
 209              (CHAR16 *)mTimeSettingsVariableName,
 210              &gEfiCallerIdGuid,
 211              NULL,
 212              &Size,
 213              (VOID *)&mTimeSettings
 214              );
 215   if (EFI_ERROR (Status) ||
 216       !IsValidTimeZone (mTimeSettings.TimeZone) ||
 217       !IsValidDaylight (mTimeSettings.Daylight))
 218   {
 219     DEBUG ((
 220       DEBUG_WARN,
 221       "%a: using default timezone/daylight settings\n",
 222       __FUNCTION__
 223       ));
 224
 225     mTimeSettings.TimeZone = EFI_UNSPECIFIED_TIMEZONE;
 226     mTimeSettings.Daylight = 0;
 227   }
 228
 229   SystemTable->RuntimeServices->GetTime       = GetTime;
 230   SystemTable->RuntimeServices->SetTime       = SetTime;
 231   SystemTable->RuntimeServices->GetWakeupTime = GetWakeupTime;
 232   SystemTable->RuntimeServices->SetWakeupTime = SetWakeupTime;
 233
 234   Status = gBS->InstallMultipleProtocolInterfaces (
 235                   &mHandle,
 236                   &gEfiRealTimeClockArchProtocolGuid,
 237                   NULL,
 238                   NULL
 239                   );
 240
 241   return Status;
 242 }