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 - 2014, ARM Ltd. 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     Status = EFI_NOT_FOUND;
  51     goto EXIT;
  52   }
  53
  54   // Check if this PrimeCell Peripheral is the PL031 Real Time Clock
  55   if (  (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID0) != 0x31)
  56       || (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID1) != 0x10)
  57       || ((MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID2) & 0xF) != 0x04)
  58       || (MmioRead8 (mPL031RtcBase + PL031_RTC_PERIPH_ID3) != 0x00)) {
  59     Status = EFI_NOT_FOUND;
  60     goto EXIT;
  61   }
  62
  63   Status = EFI_SUCCESS;
  64
  65   EXIT:
  66   return Status;
  67 }
  68
  69 EFI_STATUS
  70 InitializePL031 (
  71   VOID
  72   )
  73 {
  74   EFI_STATUS    Status;
  75
  76   // Prepare the hardware
  77   Status = IdentifyPL031();
  78   if (EFI_ERROR (Status)) {
  79     goto EXIT;
  80   }
  81
  82   // Ensure interrupts are masked. We do not want RTC interrupts in UEFI
  83   if ((MmioRead32 (mPL031RtcBase + PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER) & PL031_SET_IRQ_MASK) != PL031_SET_IRQ_MASK) {
  84     MmioOr32 (mPL031RtcBase + PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER, PL031_SET_IRQ_MASK);
  85   }
  86
  87   // Clear any existing interrupts
  88   if ((MmioRead32 (mPL031RtcBase + PL031_RTC_RIS_RAW_IRQ_STATUS_REGISTER) & PL031_IRQ_TRIGGERED) == PL031_IRQ_TRIGGERED) {
  89     MmioOr32 (mPL031RtcBase + PL031_RTC_ICR_IRQ_CLEAR_REGISTER, PL031_CLEAR_IRQ);
  90   }
  91
  92   // Start the clock counter
  93   if ((MmioRead32 (mPL031RtcBase + PL031_RTC_CR_CONTROL_REGISTER) & PL031_RTC_ENABLED) != PL031_RTC_ENABLED) {
  94     MmioOr32 (mPL031RtcBase + PL031_RTC_CR_CONTROL_REGISTER, PL031_RTC_ENABLED);
  95   }
  96
  97   mPL031Initialized = TRUE;
  98
  99   EXIT:
 100   return Status;
 101 }
 102
 103 /**
 104   Returns the current time and date information, and the time-keeping capabilities
 105   of the hardware platform.
 106
 107   @param  Time                   A pointer to storage to receive a snapshot of the current time.
 108   @param  Capabilities           An optional pointer to a buffer to receive the real time clock
 109                                  device's capabilities.
 110
 111   @retval EFI_SUCCESS            The operation completed successfully.
 112   @retval EFI_INVALID_PARAMETER  Time is NULL.
 113   @retval EFI_DEVICE_ERROR       The time could not be retrieved due to hardware error.
 114   @retval EFI_SECURITY_VIOLATION The time could not be retrieved due to an authentication failure.
 115
 116 **/
 117 EFI_STATUS
 118 EFIAPI
 119 LibGetTime (
 120   OUT EFI_TIME                *Time,
 121   OUT EFI_TIME_CAPABILITIES   *Capabilities
 122   )
 123 {
 124   EFI_STATUS  Status = EFI_SUCCESS;
 125   UINT32      EpochSeconds;
 126
 127   // Ensure Time is a valid pointer
 128   if (Time == NULL) {
 129     return EFI_INVALID_PARAMETER;
 130   }
 131
 132   // Initialize the hardware if not already done
 133   if (!mPL031Initialized) {
 134     Status = InitializePL031 ();
 135     if (EFI_ERROR (Status)) {
 136       return Status;
 137     }
 138   }
 139
 140   EpochSeconds = MmioRead32 (mPL031RtcBase + PL031_RTC_DR_DATA_REGISTER);
 141
 142   // Adjust for the correct time zone
 143   // The timezone setting also reflects the DST setting of the clock
 144   if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
 145     EpochSeconds += Time->TimeZone * SEC_PER_MIN;
 146   } else if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
 147     // Convert to adjusted time, i.e. spring forwards one hour
 148     EpochSeconds += SEC_PER_HOUR;
 149   }
 150
 151   // Convert from internal 32-bit time to UEFI time
 152   EpochToEfiTime (EpochSeconds, Time);
 153
 154   // Update the Capabilities info
 155   if (Capabilities != NULL) {
 156     // PL031 runs at frequency 1Hz
 157     Capabilities->Resolution  = PL031_COUNTS_PER_SECOND;
 158     // Accuracy in ppm multiplied by 1,000,000, e.g. for 50ppm set 50,000,000
 159     Capabilities->Accuracy    = (UINT32)PcdGet32 (PcdPL031RtcPpmAccuracy);
 160     // FALSE: Setting the time does not clear the values below the resolution level
 161     Capabilities->SetsToZero  = FALSE;
 162   }
 163
 164   return EFI_SUCCESS;
 165 }
 166
 167
 168 /**
 169   Sets the current local time and date information.
 170
 171   @param  Time                  A pointer to the current time.
 172
 173   @retval EFI_SUCCESS           The operation completed successfully.
 174   @retval EFI_INVALID_PARAMETER A time field is out of range.
 175   @retval EFI_DEVICE_ERROR      The time could not be set due due to hardware error.
 176
 177 **/
 178 EFI_STATUS
 179 EFIAPI
 180 LibSetTime (
 181   IN  EFI_TIME                *Time
 182   )
 183 {
 184   EFI_STATUS  Status;
 185   UINT32      EpochSeconds;
 186
 187   // Because the PL031 is a 32-bit counter counting seconds,
 188   // the maximum time span is just over 136 years.
 189   // Time is stored in Unix Epoch format, so it starts in 1970,
 190   // Therefore it can not exceed the year 2106.
 191   if ((Time->Year < 1970) || (Time->Year >= 2106)) {
 192     return EFI_UNSUPPORTED;
 193   }
 194
 195   // Initialize the hardware if not already done
 196   if (!mPL031Initialized) {
 197     Status = InitializePL031 ();
 198     if (EFI_ERROR (Status)) {
 199       return Status;
 200     }
 201   }
 202
 203   EpochSeconds = EfiTimeToEpoch (Time);
 204
 205   // Adjust for the correct time zone, i.e. convert to UTC time zone
 206   // The timezone setting also reflects the DST setting of the clock
 207   if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
 208     EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
 209   } else if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
 210     // Convert to un-adjusted time, i.e. fall back one hour
 211     EpochSeconds -= SEC_PER_HOUR;
 212   }
 213
 214   // Set the PL031
 215   MmioWrite32 (mPL031RtcBase + PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
 216
 217   return EFI_SUCCESS;
 218 }
 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 /**
 247   Sets the system wakeup alarm clock time.
 248
 249   @param  Enabled               Enable or disable the wakeup alarm.
 250   @param  Time                  If Enable is TRUE, the time to set the wakeup alarm for.
 251
 252   @retval EFI_SUCCESS           If Enable is TRUE, then the wakeup alarm was enabled. If
 253                                 Enable is FALSE, then the wakeup alarm was disabled.
 254   @retval EFI_INVALID_PARAMETER A time field is out of range.
 255   @retval EFI_DEVICE_ERROR      The wakeup time could not be set due to a hardware error.
 256   @retval EFI_UNSUPPORTED       A wakeup timer is not supported on this platform.
 257
 258 **/
 259 EFI_STATUS
 260 EFIAPI
 261 LibSetWakeupTime (
 262   IN BOOLEAN      Enabled,
 263   OUT EFI_TIME    *Time
 264   )
 265 {
 266   // Not a required feature
 267   return EFI_UNSUPPORTED;
 268 }
 269
 270 /**
 271   Fixup internal data so that EFI can be call in virtual mode.
 272   Call the passed in Child Notify event and convert any pointers in
 273   lib to virtual mode.
 274
 275   @param[in]    Event   The Event that is being processed
 276   @param[in]    Context Event Context
 277 **/
 278 VOID
 279 EFIAPI
 280 LibRtcVirtualNotifyEvent (
 281   IN EFI_EVENT        Event,
 282   IN VOID             *Context
 283   )
 284 {
 285   //
 286   // Only needed if you are going to support the OS calling RTC functions in virtual mode.
 287   // You will need to call EfiConvertPointer (). To convert any stored physical addresses
 288   // to virtual address. After the OS transitions to calling in virtual mode, all future
 289   // runtime calls will be made in virtual mode.
 290   //
 291   EfiConvertPointer (0x0, (VOID**)&mPL031RtcBase);
 292   return;
 293 }
 294
 295 /**
 296   This is the declaration of an EFI image entry point. This can be the entry point to an application
 297   written to this specification, an EFI boot service driver, or an EFI runtime driver.
 298
 299   @param  ImageHandle           Handle that identifies the loaded image.
 300   @param  SystemTable           System Table for this image.
 301
 302   @retval EFI_SUCCESS           The operation completed successfully.
 303
 304 **/
 305 EFI_STATUS
 306 EFIAPI
 307 LibRtcInitialize (
 308   IN EFI_HANDLE                            ImageHandle,
 309   IN EFI_SYSTEM_TABLE                      *SystemTable
 310   )
 311 {
 312   EFI_STATUS    Status;
 313   EFI_HANDLE    Handle;
 314
 315   // Initialize RTC Base Address
 316   mPL031RtcBase = PcdGet32 (PcdPL031RtcBase);
 317
 318   // Declare the controller as EFI_MEMORY_RUNTIME
 319   Status = gDS->AddMemorySpace (
 320                   EfiGcdMemoryTypeMemoryMappedIo,
 321                   mPL031RtcBase, 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,  NULL,
 338                   NULL
 339                  );
 340   ASSERT_EFI_ERROR (Status);
 341
 342   //
 343   // Register for the virtual address change event
 344   //
 345   Status = gBS->CreateEventEx (
 346                   EVT_NOTIFY_SIGNAL,
 347                   TPL_NOTIFY,
 348                   LibRtcVirtualNotifyEvent,
 349                   NULL,
 350                   &gEfiEventVirtualAddressChangeGuid,
 351                   &mRtcVirtualAddrChangeEvent
 352                   );
 353   ASSERT_EFI_ERROR (Status);
 354
 355   return Status;
 356 }