EmbeddedPkg/TemplateTimerDxe/Timer.c

   1 /** @file
   2   Template for Timer Architecture Protocol driver of the ARM flavor
   3
   4   Copyright (c) 2008-2009, Apple Inc. All rights reserved.
   5
   6   All rights reserved. This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16
  17 #include <PiDxe.h>
  18
  19 #include <Library/BaseLib.h>
  20 #include <Library/DebugLib.h>
  21 #include <Library/BaseMemoryLib.h>
  22 #include <Library/UefiBootServicesTableLib.h>
  23 #include <Library/UefiLib.h>
  24 #include <Library/PcdLib.h>
  25 #include <Library/IoLib.h>
  26
  27 #include <Protocol/Timer.h>
  28 #include <Protocol/HardwareInterrupt.h>
  29
  30 //
  31 // Get Base Address of timer block from platform .DSC file
  32 //
  33 #define TIMER_BASE ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00c0)
  34
  35
  36 #define TIMER_CMD    ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000004)
  37 #define TIMER_DATA   ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000008)
  38
  39 //
  40 // The notification function to call on every timer interrupt.
  41 // A bug in the compiler prevents us from initializing this here.
  42 //
  43 volatile EFI_TIMER_NOTIFY mTimerNotifyFunction;
  44
  45 //
  46 // The current period of the timer interrupt
  47 //
  48 volatile UINT64           mTimerPeriod = 0;
  49
  50 //
  51 // Cached copy of the Hardware Interrupt protocol instance
  52 //
  53 EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;
  54
  55
  56 /**
  57   C Interrupt Handler calledin the interrupt context when Source interrupt is active.
  58
  59   @param Source         Source of the interrupt. Hardware routing off a specific platform defines
  60                         what source means.
  61   @param SystemContext  Pointer to system register context. Mostly used by debuggers and will
  62                         update the system context after the return from the interrupt if
  63                         modified. Don't change these values unless you know what you are doing
  64
  65 **/
  66 VOID
  67 EFIAPI
  68 TimerInterruptHandler (
  69         IN HARDWARE_INTERRUPT_SOURCE            Source,
  70   IN  EFI_SYSTEM_CONTEXT          SystemContext
  71         )
  72 {
  73         EFI_TPL                                                 OriginalTPL;
  74
  75   //
  76   // DXE core uses this callback for the EFI timer tick. The DXE core uses locks
  77   // that raise to TPL_HIGH and then restore back to current level. Thus we need
  78   // to make sure TPL level is set to TPL_HIGH while we are handling the timer tick.
  79   //
  80         OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
  81
  82   MmioWrite32 (TIMER_CMD, 0);
  83
  84         if (mTimerNotifyFunction) {
  85                 mTimerNotifyFunction (mTimerPeriod);
  86         }
  87
  88   // restore state
  89         gBS->RestoreTPL (OriginalTPL);
  90 }
  91
  92
  93
  94 /**
  95   This function registers the handler NotifyFunction so it is called every time
  96   the timer interrupt fires.  It also passes the amount of time since the last
  97   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  98   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  99   returned.  If the CPU does not support registering a timer interrupt handler,
 100   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
 101   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
 102   If an attempt is made to unregister a handler when a handler is not registered,
 103   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
 104   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
 105   is returned.
 106
 107   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 108   @param  NotifyFunction   The function to call when a timer interrupt fires. This
 109                            function executes at TPL_HIGH_LEVEL. The DXE Core will
 110                            register a handler for the timer interrupt, so it can know
 111                            how much time has passed. This information is used to
 112                            signal timer based events. NULL will unregister the handler.
 113
 114   @retval EFI_SUCCESS           The timer handler was registered.
 115   @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.
 116   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
 117                                 registered.
 118   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
 119                                 previously registered.
 120   @retval EFI_DEVICE_ERROR      The timer handler could not be registered.
 121
 122 **/
 123 EFI_STATUS
 124 EFIAPI
 125 TimerDriverRegisterHandler (
 126   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 127   IN EFI_TIMER_NOTIFY         NotifyFunction
 128   )
 129 {
 130   //
 131   // Check for invalid parameters
 132   //
 133   if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
 134     return EFI_INVALID_PARAMETER;
 135   }
 136
 137   if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
 138     return EFI_ALREADY_STARTED;
 139   }
 140
 141   mTimerNotifyFunction = NotifyFunction;
 142
 143   return EFI_SUCCESS;
 144 }
 145
 146
 147
 148 /**
 149   This function adjusts the period of timer interrupts to the value specified
 150   by TimerPeriod.  If the timer period is updated, then the selected timer
 151   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 152   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 153   If an error occurs while attempting to update the timer period, then the
 154   timer hardware will be put back in its state prior to this call, and
 155   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 156   is disabled.  This is not the same as disabling the CPU's interrupts.
 157   Instead, it must either turn off the timer hardware, or it must adjust the
 158   interrupt controller so that a CPU interrupt is not generated when the timer
 159   interrupt fires.
 160
 161   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 162   @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
 163                            the timer hardware is not programmable, then EFI_UNSUPPORTED is
 164                            returned. If the timer is programmable, then the timer period
 165                            will be rounded up to the nearest timer period that is supported
 166                            by the timer hardware. If TimerPeriod is set to 0, then the
 167                            timer interrupts will be disabled.
 168
 169   @retval EFI_SUCCESS           The timer period was changed.
 170   @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
 171   @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.
 172
 173 **/
 174 EFI_STATUS
 175 EFIAPI
 176 TimerDriverSetTimerPeriod (
 177   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 178   IN UINT64                   TimerPeriod
 179   )
 180 {
 181   EFI_STATUS  Status;
 182   UINT64      TimerCount;
 183
 184   if (TimerPeriod == 0) {
 185     //
 186     // Disable interrupt 0 and timer
 187     //
 188     MmioAnd32 (TIMER_DATA, 0);
 189
 190                 Status = gInterrupt->DisableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector));
 191   } else {
 192                 //
 193                 // Convert TimerPeriod into Timer F counts
 194                 //
 195                 TimerCount = DivU64x32 (TimerPeriod + 5, 10);
 196
 197                 //
 198                 // Program Timer F with the new count value
 199                 //
 200                 MmioWrite32 (TIMER_DATA, (UINT32)TimerCount);
 201
 202                 //
 203                 // Enable interrupt and initialize and enable timer.
 204                 //
 205                 MmioOr32 (TIMER_CMD, 0x11);
 206
 207                 Status = gInterrupt->EnableInterruptSource (gInterrupt,  FixedPcdGet32 (PcdTimerVector));
 208   }
 209
 210         //
 211         // Save the new timer period
 212         //
 213         mTimerPeriod = TimerPeriod;
 214   return Status;
 215 }
 216
 217
 218 /**
 219   This function retrieves the period of timer interrupts in 100 ns units,
 220   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 221   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 222   returned, then the timer is currently disabled.
 223
 224   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 225   @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If
 226                            0 is returned, then the timer is currently disabled.
 227
 228   @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.
 229   @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
 230
 231 **/
 232 EFI_STATUS
 233 EFIAPI
 234 TimerDriverGetTimerPeriod (
 235   IN EFI_TIMER_ARCH_PROTOCOL   *This,
 236   OUT UINT64                   *TimerPeriod
 237   )
 238 {
 239   if (TimerPeriod == NULL) {
 240     return EFI_INVALID_PARAMETER;
 241   }
 242
 243   *TimerPeriod = mTimerPeriod;
 244   return EFI_SUCCESS;
 245 }
 246
 247
 248
 249 /**
 250   This function generates a soft timer interrupt. If the platform does not support soft
 251   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 252   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 253   service, then a soft timer interrupt will be generated. If the timer interrupt is
 254   enabled when this service is called, then the registered handler will be invoked. The
 255   registered handler should not be able to distinguish a hardware-generated timer
 256   interrupt from a software-generated timer interrupt.
 257
 258   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 259
 260   @retval EFI_SUCCESS           The soft timer interrupt was generated.
 261   @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.
 262
 263 **/
 264 EFI_STATUS
 265 EFIAPI
 266 TimerDriverGenerateSoftInterrupt (
 267   IN EFI_TIMER_ARCH_PROTOCOL  *This
 268   )
 269 {
 270   return EFI_UNSUPPORTED;
 271 }
 272
 273
 274 /**
 275   Interface stucture for the Timer Architectural Protocol.
 276
 277   @par Protocol Description:
 278   This protocol provides the services to initialize a periodic timer
 279   interrupt, and to register a handler that is called each time the timer
 280   interrupt fires.  It may also provide a service to adjust the rate of the
 281   periodic timer interrupt.  When a timer interrupt occurs, the handler is
 282   passed the amount of time that has passed since the previous timer
 283   interrupt.
 284
 285   @param RegisterHandler
 286   Registers a handler that will be called each time the
 287   timer interrupt fires.  TimerPeriod defines the minimum
 288   time between timer interrupts, so TimerPeriod will also
 289   be the minimum time between calls to the registered
 290   handler.
 291
 292   @param SetTimerPeriod
 293   Sets the period of the timer interrupt in 100 nS units.
 294   This function is optional, and may return EFI_UNSUPPORTED.
 295   If this function is supported, then the timer period will
 296   be rounded up to the nearest supported timer period.
 297
 298   @param GetTimerPeriod
 299   Retrieves the period of the timer interrupt in 100 nS units.
 300
 301   @param GenerateSoftInterrupt
 302   Generates a soft timer interrupt that simulates the firing of
 303   the timer interrupt. This service can be used to invoke the
 304   registered handler if the timer interrupt has been masked for
 305   a period of time.
 306
 307 **/
 308 EFI_TIMER_ARCH_PROTOCOL   gTimer = {
 309   TimerDriverRegisterHandler,
 310   TimerDriverSetTimerPeriod,
 311   TimerDriverGetTimerPeriod,
 312   TimerDriverGenerateSoftInterrupt
 313 };
 314
 315 EFI_HANDLE  gTimerHandle = NULL;
 316
 317
 318 /**
 319   Initialize the state information for the Timer Architectural Protocol
 320
 321   @param  ImageHandle   of the loaded driver
 322   @param  SystemTable   Pointer to the System Table
 323
 324   @retval EFI_SUCCESS           Protocol registered
 325   @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
 326   @retval EFI_DEVICE_ERROR      Hardware problems
 327
 328 **/
 329 EFI_STATUS
 330 EFIAPI
 331 TimerInitialize (
 332   IN EFI_HANDLE         ImageHandle,
 333   IN EFI_SYSTEM_TABLE   *SystemTable
 334   )
 335 {
 336   EFI_STATUS  Status;
 337
 338         //
 339         // Find the interrupt controller protocol.  ASSERT if not found.
 340         //
 341         Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, ( VOID ** )&gInterrupt);
 342         ASSERT_EFI_ERROR (Status);
 343
 344   MmioWrite32 (TIMER_CMD, 0x01);
 345
 346   //
 347   // Force the timer to be disabled
 348   //
 349   Status = TimerDriverSetTimerPeriod (&gTimer, 0);
 350         ASSERT_EFI_ERROR (Status);
 351
 352   //
 353   // Install interrupt handler
 354   //
 355   Status = gInterrupt->RegisterInterruptSource (gInterrupt,  FixedPcdGet32 (PcdTimerVector), TimerInterruptHandler);
 356         ASSERT_EFI_ERROR (Status);
 357
 358         //
 359         // Force the timer to be enabled at its default period
 360         //
 361         Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32 (PcdTimerPeriod));
 362         ASSERT_EFI_ERROR (Status);
 363
 364
 365   //
 366   // Install the Timer Architectural Protocol onto a new handle
 367   //
 368   Status = gBS->InstallMultipleProtocolInterfaces (
 369                   &gTimerHandle,
 370                   &gEfiTimerArchProtocolGuid,  &gTimer,
 371                   NULL
 372                   );
 373   ASSERT_EFI_ERROR (Status);
 374
 375   return Status;
 376 }
 377