ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c

   1 /** @file
   2   Implement EFI RealTimeClock runtime services via RTC Lib.
   3
   4   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   5   Copyright (c) 2011 - 2020, Arm Limited. All rights reserved.<BR>
   6   Copyright (c) 2019, Linaro Ltd. All rights reserved.<BR>
   7
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <PiDxe.h>
  13
  14 #include <Guid/EventGroup.h>
  15 #include <Guid/GlobalVariable.h>
  16
  17 #include <Library/BaseLib.h>
  18 #include <Library/DebugLib.h>
  19 #include <Library/DxeServicesTableLib.h>
  20 #include <Library/IoLib.h>
  21 #include <Library/MemoryAllocationLib.h>
  22 #include <Library/PcdLib.h>
  23 #include <Library/RealTimeClockLib.h>
  24 #include <Library/TimeBaseLib.h>
  25 #include <Library/UefiBootServicesTableLib.h>
  26 #include <Library/UefiLib.h>
  27 #include <Library/UefiRuntimeServicesTableLib.h>
  28 #include <Library/UefiRuntimeLib.h>
  29
  30 #include <Protocol/RealTimeClock.h>
  31
  32 #include "PL031RealTimeClock.h"
  33
  34 STATIC BOOLEAN    mPL031Initialized = FALSE;
  35 STATIC EFI_EVENT  mRtcVirtualAddrChangeEvent;
  36 STATIC UINTN      mPL031RtcBase;
  37
  38 EFI_STATUS
  39 IdentifyPL031 (
  40   VOID
  41   )
  42 {
  43   EFI_STATUS  Status;
  44
  45   // Check if this is a PrimeCell Peripheral
  46   if (  (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID0) != 0x0D)
  47      || (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID1) != 0xF0)
  48      || (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID2) != 0x05)
  49      || (MmioRead8 (mPL031RtcBase + PL031_RTC_PCELL_ID3) != 0xB1))
  50   {
  51     Status = EFI_NOT_FOUND;
  52     goto EXIT;
  53   }
  54
  55   // Check if this PrimeCell Peripheral is the PL031 Real Time Clock
  56   if (  (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID0) != 0x31)
  57      || (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID1) != 0x10)
  58      || ((MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID2) & 0xF) != 0x04)
  59      || (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID3) != 0x00))
  60   {
  61     Status = EFI_NOT_FOUND;
  62     goto EXIT;
  63   }
  64
  65   Status = EFI_SUCCESS;
  66
  67 EXIT:
  68   return Status;
  69 }
  70
  71 EFI_STATUS
  72 InitializePL031 (
  73   VOID
  74   )
  75 {
  76   EFI_STATUS  Status;
  77
  78   // Prepare the hardware
  79   Status = IdentifyPL031 ();
  80   if (EFI_ERROR (Status)) {
  81     goto EXIT;
  82   }
  83
  84   // Ensure interrupts are masked. We do not want RTC interrupts in UEFI
  85   if ((MmioRead32 (mPL031RtcBase + PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER) & PL031_SET_IRQ_MASK) != 0) {
  86     MmioWrite32 (mPL031RtcBase + PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER, 0);
  87   }
  88
  89   // Clear any existing interrupts
  90   if ((MmioRead32 (mPL031RtcBase + PL031_RTC_RIS_RAW_IRQ_STATUS_REGISTER) & PL031_IRQ_TRIGGERED) == PL031_IRQ_TRIGGERED) {
  91     MmioOr32 (mPL031RtcBase + PL031_RTC_ICR_IRQ_CLEAR_REGISTER, PL031_CLEAR_IRQ);
  92   }
  93
  94   // Start the clock counter
  95   if ((MmioRead32 (mPL031RtcBase + PL031_RTC_CR_CONTROL_REGISTER) & PL031_RTC_ENABLED) != PL031_RTC_ENABLED) {
  96     MmioOr32 (mPL031RtcBase + PL031_RTC_CR_CONTROL_REGISTER, PL031_RTC_ENABLED);
  97   }
  98
  99   mPL031Initialized = TRUE;
 100
 101 EXIT:
 102   return Status;
 103 }
 104
 105 /**
 106   Returns the current time and date information, and the time-keeping capabilities
 107   of the hardware platform.
 108
 109   @param  Time                   A pointer to storage to receive a snapshot of the current time.
 110   @param  Capabilities           An optional pointer to a buffer to receive the real time clock
 111                                  device's capabilities.
 112
 113   @retval EFI_SUCCESS            The operation completed successfully.
 114   @retval EFI_INVALID_PARAMETER  Time is NULL.
 115   @retval EFI_DEVICE_ERROR       The time could not be retrieved due to hardware error.
 116   @retval EFI_SECURITY_VIOLATION The time could not be retrieved due to an authentication failure.
 117
 118 **/
 119 EFI_STATUS
 120 EFIAPI
 121 LibGetTime (
 122   OUT EFI_TIME               *Time,
 123   OUT EFI_TIME_CAPABILITIES  *Capabilities
 124   )
 125 {
 126   EFI_STATUS  Status;
 127   UINT32      EpochSeconds;
 128
 129   // Ensure Time is a valid pointer
 130   if (Time == NULL) {
 131     return EFI_INVALID_PARAMETER;
 132   }
 133
 134   // Initialize the hardware if not already done
 135   if (!mPL031Initialized) {
 136     Status = InitializePL031 ();
 137     if (EFI_ERROR (Status)) {
 138       return Status;
 139     }
 140   }
 141
 142   EpochSeconds = MmioRead32 (mPL031RtcBase + PL031_RTC_DR_DATA_REGISTER);
 143
 144   // Adjust for the correct time zone
 145   // The timezone setting also reflects the DST setting of the clock
 146   if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
 147     EpochSeconds += Time->TimeZone * SEC_PER_MIN;
 148   } else if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
 149     // Convert to adjusted time, i.e. spring forwards one hour
 150     EpochSeconds += SEC_PER_HOUR;
 151   }
 152
 153   // Convert from internal 32-bit time to UEFI time
 154   EpochToEfiTime (EpochSeconds, Time);
 155
 156   // Update the Capabilities info
 157   if (Capabilities != NULL) {
 158     // PL031 runs at frequency 1Hz
 159     Capabilities->Resolution = PL031_COUNTS_PER_SECOND;
 160     // Accuracy in ppm multiplied by 1,000,000, e.g. for 50ppm set 50,000,000
 161     Capabilities->Accuracy = (UINT32)PcdGet32 (PcdPL031RtcPpmAccuracy);
 162     // FALSE: Setting the time does not clear the values below the resolution level
 163     Capabilities->SetsToZero = FALSE;
 164   }
 165
 166   return EFI_SUCCESS;
 167 }
 168
 169 /**
 170   Sets the current local time and date information.
 171
 172   @param  Time                  A pointer to the current time.
 173
 174   @retval EFI_SUCCESS           The operation completed successfully.
 175   @retval EFI_INVALID_PARAMETER A time field is out of range.
 176   @retval EFI_DEVICE_ERROR      The time could not be set due to hardware error.
 177
 178 **/
 179 EFI_STATUS
 180 EFIAPI
 181 LibSetTime (
 182   IN  EFI_TIME  *Time
 183   )
 184 {
 185   EFI_STATUS  Status;
 186   UINT32      EpochSeconds;
 187
 188   // Because the PL031 is a 32-bit counter counting seconds,
 189   // the maximum time span is just over 136 years.
 190   // Time is stored in Unix Epoch format, so it starts in 1970,
 191   // Therefore it can not exceed the year 2106.
 192   if ((Time->Year < 1970) || (Time->Year >= 2106)) {
 193     return EFI_UNSUPPORTED;
 194   }
 195
 196   // Initialize the hardware if not already done
 197   if (!mPL031Initialized) {
 198     Status = InitializePL031 ();
 199     if (EFI_ERROR (Status)) {
 200       return Status;
 201     }
 202   }
 203
 204   EpochSeconds = (UINT32)EfiTimeToEpoch (Time);
 205
 206   // Adjust for the correct time zone, i.e. convert to UTC time zone
 207   // The timezone setting also reflects the DST setting of the clock
 208   if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
 209     EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
 210   } else if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
 211     // Convert to un-adjusted time, i.e. fall back one hour
 212     EpochSeconds -= SEC_PER_HOUR;
 213   }
 214
 215   // Set the PL031
 216   MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
 217
 218   return EFI_SUCCESS;
 219 }
 220
 221 /**
 222   Returns the current wakeup alarm clock setting.
 223
 224   @param  Enabled               Indicates if the alarm is currently enabled or disabled.
 225   @param  Pending               Indicates if the alarm signal is pending and requires acknowledgement.
 226   @param  Time                  The current alarm setting.
 227
 228   @retval EFI_SUCCESS           The alarm settings were returned.
 229   @retval EFI_INVALID_PARAMETER Any parameter is NULL.
 230   @retval EFI_DEVICE_ERROR      The wakeup time could not be retrieved due to a hardware error.
 231
 232 **/
 233 EFI_STATUS
 234 EFIAPI
 235 LibGetWakeupTime (
 236   OUT BOOLEAN   *Enabled,
 237   OUT BOOLEAN   *Pending,
 238   OUT EFI_TIME  *Time
 239   )
 240 {
 241   // Not a required feature
 242   return EFI_UNSUPPORTED;
 243 }
 244
 245 /**
 246   Sets the system wakeup alarm clock time.
 247
 248   @param  Enabled               Enable or disable the wakeup alarm.
 249   @param  Time                  If Enable is TRUE, the time to set the wakeup alarm for.
 250
 251   @retval EFI_SUCCESS           If Enable is TRUE, then the wakeup alarm was enabled. If
 252                                 Enable is FALSE, then the wakeup alarm was disabled.
 253   @retval EFI_INVALID_PARAMETER A time field is out of range.
 254   @retval EFI_DEVICE_ERROR      The wakeup time could not be set due to a hardware error.
 255   @retval EFI_UNSUPPORTED       A wakeup timer is not supported on this platform.
 256
 257 **/
 258 EFI_STATUS
 259 EFIAPI
 260 LibSetWakeupTime (
 261   IN BOOLEAN    Enabled,
 262   OUT EFI_TIME  *Time
 263   )
 264 {
 265   // Not a required feature
 266   return EFI_UNSUPPORTED;
 267 }
 268
 269 /**
 270   Fixup internal data so that EFI can be call in virtual mode.
 271   Call the passed in Child Notify event and convert any pointers in
 272   lib to virtual mode.
 273
 274   @param[in]    Event   The Event that is being processed
 275   @param[in]    Context Event Context
 276 **/
 277 VOID
 278 EFIAPI
 279 LibRtcVirtualNotifyEvent (
 280   IN EFI_EVENT  Event,
 281   IN VOID       *Context
 282   )
 283 {
 284   //
 285   // Only needed if you are going to support the OS calling RTC functions in virtual mode.
 286   // You will need to call EfiConvertPointer (). To convert any stored physical addresses
 287   // to virtual address. After the OS transitions to calling in virtual mode, all future
 288   // runtime calls will be made in virtual mode.
 289   //
 290   EfiConvertPointer (0x0, (VOID **)&mPL031RtcBase);
 291   return;
 292 }
 293
 294 /**
 295   This is the declaration of an EFI image entry point. This can be the entry point to an application
 296   written to this specification, an EFI boot service driver, or an EFI runtime driver.
 297
 298   @param  ImageHandle           Handle that identifies the loaded image.
 299   @param  SystemTable           System Table for this image.
 300
 301   @retval EFI_SUCCESS           The operation completed successfully.
 302
 303 **/
 304 EFI_STATUS
 305 EFIAPI
 306 LibRtcInitialize (
 307   IN EFI_HANDLE        ImageHandle,
 308   IN EFI_SYSTEM_TABLE  *SystemTable
 309   )
 310 {
 311   EFI_STATUS  Status;
 312   EFI_HANDLE  Handle;
 313
 314   // Initialize RTC Base Address
 315   mPL031RtcBase = PcdGet32 (PcdPL031RtcBase);
 316
 317   // Declare the controller as EFI_MEMORY_RUNTIME
 318   Status = gDS->AddMemorySpace (
 319                   EfiGcdMemoryTypeMemoryMappedIo,
 320                   mPL031RtcBase,
 321                   SIZE_4KB,
 322                   EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
 323                   );
 324   if (EFI_ERROR (Status)) {
 325     return Status;
 326   }
 327
 328   Status = gDS->SetMemorySpaceAttributes (mPL031RtcBase, SIZE_4KB, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME);
 329   if (EFI_ERROR (Status)) {
 330     return Status;
 331   }
 332
 333   // Install the protocol
 334   Handle = NULL;
 335   Status = gBS->InstallMultipleProtocolInterfaces (
 336                   &Handle,
 337                   &gEfiRealTimeClockArchProtocolGuid,
 338                   NULL,
 339                   NULL
 340                   );
 341   ASSERT_EFI_ERROR (Status);
 342
 343   //
 344   // Register for the virtual address change event
 345   //
 346   Status = gBS->CreateEventEx (
 347                   EVT_NOTIFY_SIGNAL,
 348                   TPL_NOTIFY,
 349                   LibRtcVirtualNotifyEvent,
 350                   NULL,
 351                   &gEfiEventVirtualAddressChangeGuid,
 352                   &mRtcVirtualAddrChangeEvent
 353                   );
 354   ASSERT_EFI_ERROR (Status);
 355
 356   return Status;
 357 }