ArmEbPkg/TimerDxe/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.<BR>
   5
   6   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 #include <ArmEb/ArmEb.h>
  31
  32
  33 // The notification function to call on every timer interrupt.
  34 volatile EFI_TIMER_NOTIFY      mTimerNotifyFunction   = (EFI_TIMER_NOTIFY)NULL;
  35
  36
  37 // The current period of the timer interrupt
  38 volatile UINT64 mTimerPeriod = 0;
  39
  40 // Cached copy of the Hardware Interrupt protocol instance
  41 EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;
  42
  43 // Cached interrupt vector
  44 UINTN  gVector;
  45
  46 UINT32 mLastTickCount;
  47
  48
  49 /**
  50
  51   C Interrupt Handler calledin the interrupt context when Source interrupt is active.
  52
  53
  54   @param Source         Source of the interrupt. Hardware routing off a specific platform defines
  55                         what source means.
  56
  57   @param SystemContext  Pointer to system register context. Mostly used by debuggers and will
  58                         update the system context after the return from the interrupt if
  59                         modified. Don't change these values unless you know what you are doing
  60
  61 **/
  62 VOID
  63 EFIAPI
  64 TimerInterruptHandler (
  65   IN  HARDWARE_INTERRUPT_SOURCE   Source,
  66   IN  EFI_SYSTEM_CONTEXT          SystemContext
  67   )
  68 {
  69   EFI_TPL OriginalTPL;
  70
  71   //
  72   // DXE core uses this callback for the EFI timer tick. The DXE core uses locks
  73   // that raise to TPL_HIGH and then restore back to current level. Thus we need
  74   // to make sure TPL level is set to TPL_HIGH while we are handling the timer tick.
  75   //
  76   OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
  77
  78   // clear the periodic interrupt
  79   MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_INT_CLR_REG, 0);
  80
  81   // signal end of interrupt early to help avoid losing subsequent ticks from long duration handlers
  82   gInterrupt->EndOfInterrupt (gInterrupt, Source);
  83
  84   if (mTimerNotifyFunction) {
  85     mTimerNotifyFunction (mTimerPeriod);
  86   }
  87
  88   gBS->RestoreTPL (OriginalTPL);
  89 }
  90
  91
  92 /**
  93   This function registers the handler NotifyFunction so it is called every time
  94   the timer interrupt fires.  It also passes the amount of time since the last
  95   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  96   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  97   returned.  If the CPU does not support registering a timer interrupt handler,
  98   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
  99   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
 100   If an attempt is made to unregister a handler when a handler is not registered,
 101   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
 102   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
 103   is returned.
 104
 105   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 106   @param  NotifyFunction   The function to call when a timer interrupt fires. This
 107                            function executes at TPL_HIGH_LEVEL. The DXE Core will
 108                            register a handler for the timer interrupt, so it can know
 109                            how much time has passed. This information is used to
 110                            signal timer based events. NULL will unregister the handler.
 111   @retval EFI_SUCCESS           The timer handler was registered.
 112   @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.
 113   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
 114                                 registered.
 115   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
 116                                 previously registered.
 117   @retval EFI_DEVICE_ERROR      The timer handler could not be registered.
 118
 119 **/
 120 EFI_STATUS
 121 EFIAPI
 122 TimerDriverRegisterHandler (
 123   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 124   IN EFI_TIMER_NOTIFY         NotifyFunction
 125   )
 126 {
 127   if ((NotifyFunction == NULL) && (mTimerNotifyFunction == NULL)) {
 128     return EFI_INVALID_PARAMETER;
 129   }
 130
 131   if ((NotifyFunction != NULL) && (mTimerNotifyFunction != NULL)) {
 132     return EFI_ALREADY_STARTED;
 133   }
 134
 135   mTimerNotifyFunction = NotifyFunction;
 136
 137   return EFI_SUCCESS;
 138 }
 139
 140 /**
 141
 142   This function adjusts the period of timer interrupts to the value specified
 143   by TimerPeriod.  If the timer period is updated, then the selected timer
 144   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 145   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 146   If an error occurs while attempting to update the timer period, then the
 147   timer hardware will be put back in its state prior to this call, and
 148   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 149   is disabled.  This is not the same as disabling the CPU's interrupts.
 150   Instead, it must either turn off the timer hardware, or it must adjust the
 151   interrupt controller so that a CPU interrupt is not generated when the timer
 152   interrupt fires.
 153
 154   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 155   @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
 156                            the timer hardware is not programmable, then EFI_UNSUPPORTED is
 157                            returned. If the timer is programmable, then the timer period
 158                            will be rounded up to the nearest timer period that is supported
 159                            by the timer hardware. If TimerPeriod is set to 0, then the
 160                            timer interrupts will be disabled.
 161
 162
 163   @retval EFI_SUCCESS           The timer period was changed.
 164   @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
 165   @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.
 166
 167 **/
 168 EFI_STATUS
 169 EFIAPI
 170 TimerDriverSetTimerPeriod (
 171   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 172   IN UINT64                   TimerPeriod
 173   )
 174 {
 175   EFI_STATUS  Status;
 176   UINT64      TimerTicks;
 177
 178   // always disable the timer
 179   MmioAnd32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, ~SP804_TIMER_CTRL_ENABLE);
 180
 181   if (TimerPeriod == 0) {
 182     // leave timer disabled from above, and...
 183     // disable timer 0/1 interrupt for a TimerPeriod of 0
 184
 185     Status = gInterrupt->DisableInterruptSource (gInterrupt, gVector);
 186   } else {
 187     // Convert TimerPeriod into 1MHz clock counts (us units = 100ns units / 10)
 188     TimerTicks = DivU64x32 (TimerPeriod, 10);
 189
 190     // if it's larger than 32-bits, pin to highest value
 191     if (TimerTicks > 0xffffffff) {
 192       TimerTicks = 0xffffffff;
 193     }
 194
 195     // Program the SP804 timer with the new count value
 196     MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_LOAD_REG, TimerTicks);
 197
 198     // enable the timer
 199     MmioOr32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
 200
 201     // enable timer 0/1 interrupts
 202     Status = gInterrupt->EnableInterruptSource (gInterrupt, gVector);
 203   }
 204
 205   //
 206   // Save the new timer period
 207   //
 208   mTimerPeriod = TimerPeriod;
 209   return Status;
 210 }
 211
 212
 213 /**
 214   This function retrieves the period of timer interrupts in 100 ns units,
 215   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 216   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 217   returned, then the timer is currently disabled.
 218
 219   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 220   @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If
 221                            0 is returned, then the timer is currently disabled.
 222
 223
 224   @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.
 225   @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
 226
 227 **/
 228 EFI_STATUS
 229 EFIAPI
 230 TimerDriverGetTimerPeriod (
 231   IN EFI_TIMER_ARCH_PROTOCOL   *This,
 232   OUT UINT64                   *TimerPeriod
 233   )
 234 {
 235   if (TimerPeriod == NULL) {
 236     return EFI_INVALID_PARAMETER;
 237   }
 238
 239   *TimerPeriod = mTimerPeriod;
 240   return EFI_SUCCESS;
 241 }
 242
 243 /**
 244   This function generates a soft timer interrupt. If the platform does not support soft
 245   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 246   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 247   service, then a soft timer interrupt will be generated. If the timer interrupt is
 248   enabled when this service is called, then the registered handler will be invoked. The
 249   registered handler should not be able to distinguish a hardware-generated timer
 250   interrupt from a software-generated timer interrupt.
 251
 252   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 253
 254   @retval EFI_SUCCESS           The soft timer interrupt was generated.
 255   @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.
 256
 257 **/
 258 EFI_STATUS
 259 EFIAPI
 260 TimerDriverGenerateSoftInterrupt (
 261   IN EFI_TIMER_ARCH_PROTOCOL  *This
 262   )
 263 {
 264   return EFI_UNSUPPORTED;
 265 }
 266
 267
 268
 269 /**
 270   Interface stucture for the Timer Architectural Protocol.
 271
 272   @par Protocol Description:
 273   This protocol provides the services to initialize a periodic timer
 274   interrupt, and to register a handler that is called each time the timer
 275   interrupt fires.  It may also provide a service to adjust the rate of the
 276   periodic timer interrupt.  When a timer interrupt occurs, the handler is
 277   passed the amount of time that has passed since the previous timer
 278   interrupt.
 279
 280   @param RegisterHandler
 281   Registers a handler that will be called each time the
 282   timer interrupt fires.  TimerPeriod defines the minimum
 283   time between timer interrupts, so TimerPeriod will also
 284   be the minimum time between calls to the registered
 285   handler.
 286
 287   @param SetTimerPeriod
 288   Sets the period of the timer interrupt in 100 nS units.
 289   This function is optional, and may return EFI_UNSUPPORTED.
 290   If this function is supported, then the timer period will
 291   be rounded up to the nearest supported timer period.
 292
 293
 294   @param GetTimerPeriod
 295   Retrieves the period of the timer interrupt in 100 nS units.
 296
 297   @param GenerateSoftInterrupt
 298   Generates a soft timer interrupt that simulates the firing of
 299   the timer interrupt. This service can be used to invoke the   registered handler if the timer interrupt has been masked for
 300   a period of time.
 301
 302 **/
 303 EFI_TIMER_ARCH_PROTOCOL   gTimer = {
 304   TimerDriverRegisterHandler,
 305   TimerDriverSetTimerPeriod,
 306   TimerDriverGetTimerPeriod,
 307   TimerDriverGenerateSoftInterrupt
 308 };
 309
 310
 311 /**
 312   Initialize the state information for the Timer Architectural Protocol and
 313   the Timer Debug support protocol that allows the debugger to break into a
 314   running program.
 315
 316   @param  ImageHandle   of the loaded driver
 317   @param  SystemTable   Pointer to the System Table
 318
 319   @retval EFI_SUCCESS           Protocol registered
 320   @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
 321   @retval EFI_DEVICE_ERROR      Hardware problems
 322
 323 **/
 324 EFI_STATUS
 325 EFIAPI
 326 TimerInitialize (
 327   IN EFI_HANDLE         ImageHandle,
 328   IN EFI_SYSTEM_TABLE   *SystemTable
 329   )
 330 {
 331   EFI_HANDLE  Handle = NULL;
 332   EFI_STATUS  Status;
 333   UINT32      TimerBaseAddress;
 334
 335   // configure free running timer (TIMER1) for 1MHz operation
 336
 337   // AND disable clock, OR configure 1MHz clock
 338   MmioAndThenOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER1_EN, SP810_SYS_CTRL_TIMER1_TIMCLK);
 339
 340   // Renable timer
 341   MmioOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, SP810_SYS_CTRL_TIMER1_EN);
 342
 343
 344   // configure timer 1 for free running operation, 32 bits, no prescaler, interrupt disabled
 345   MmioWrite32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
 346
 347   // enable the free running timer
 348   MmioOr32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
 349
 350   // record free running tick value (should be close to 0xffffffff)
 351   mLastTickCount = MmioRead32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CURRENT_REG);
 352
 353   // Disable the timer
 354   Status = TimerDriverSetTimerPeriod (&gTimer, 0);
 355   ASSERT_EFI_ERROR (Status);
 356
 357   // Install interrupt handler
 358   gVector = EB_TIMER01_INTERRUPT_NUM;
 359   Status = gInterrupt->RegisterInterruptSource (gInterrupt, gVector, TimerInterruptHandler);
 360   ASSERT_EFI_ERROR (Status);
 361
 362
 363   // configure periodic timer (TIMER0) for 1MHz operation
 364   MmioAndThenOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER0_EN, SP810_SYS_CTRL_TIMER0_TIMCLK);
 365
 366   // Renable timer
 367   MmioOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, SP810_SYS_CTRL_TIMER0_EN);
 368
 369   // configure timer 0 for periodic operation, 32 bits, no prescaler, and interrupt enabled
 370   MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_PERIODIC | SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1 | SP804_TIMER_CTRL_INT_ENABLE);
 371
 372
 373   // Set up default timer
 374   Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod)); // TIMER_DEFAULT_PERIOD
 375   ASSERT_EFI_ERROR (Status);
 376
 377   // Install the Timer Architectural Protocol onto a new handle
 378   Status = gBS->InstallMultipleProtocolInterfaces(
 379                   &Handle,
 380                   &gEfiTimerArchProtocolGuid,      &gTimer,
 381                   NULL
 382                   );
 383   ASSERT_EFI_ERROR(Status);
 384
 385   return Status;
 386 }
 387