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   // Mask all interrupts
  76         OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
  77
  78   MmioWrite32 (TIMER_CMD, 0);
  79
  80         if (mTimerNotifyFunction) {
  81                 mTimerNotifyFunction (mTimerPeriod);
  82         }
  83
  84   // restore state
  85         gBS->RestoreTPL (OriginalTPL);
  86 }
  87
  88
  89
  90 /**
  91   This function registers the handler NotifyFunction so it is called every time
  92   the timer interrupt fires.  It also passes the amount of time since the last
  93   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  94   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  95   returned.  If the CPU does not support registering a timer interrupt handler,
  96   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
  97   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  98   If an attempt is made to unregister a handler when a handler is not registered,
  99   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
 100   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
 101   is returned.
 102
 103   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 104   @param  NotifyFunction   The function to call when a timer interrupt fires. This
 105                            function executes at TPL_HIGH_LEVEL. The DXE Core will
 106                            register a handler for the timer interrupt, so it can know
 107                            how much time has passed. This information is used to
 108                            signal timer based events. NULL will unregister the handler.
 109
 110   @retval EFI_SUCCESS           The timer handler was registered.
 111   @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.
 112   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
 113                                 registered.
 114   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
 115                                 previously registered.
 116   @retval EFI_DEVICE_ERROR      The timer handler could not be registered.
 117
 118 **/
 119 EFI_STATUS
 120 EFIAPI
 121 TimerDriverRegisterHandler (
 122   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 123   IN EFI_TIMER_NOTIFY         NotifyFunction
 124   )
 125 {
 126   //
 127   // Check for invalid parameters
 128   //
 129   if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
 130     return EFI_INVALID_PARAMETER;
 131   }
 132
 133   if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
 134     return EFI_ALREADY_STARTED;
 135   }
 136
 137   mTimerNotifyFunction = NotifyFunction;
 138
 139   return EFI_SUCCESS;
 140 }
 141
 142
 143
 144 /**
 145   This function adjusts the period of timer interrupts to the value specified
 146   by TimerPeriod.  If the timer period is updated, then the selected timer
 147   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 148   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 149   If an error occurs while attempting to update the timer period, then the
 150   timer hardware will be put back in its state prior to this call, and
 151   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 152   is disabled.  This is not the same as disabling the CPU's interrupts.
 153   Instead, it must either turn off the timer hardware, or it must adjust the
 154   interrupt controller so that a CPU interrupt is not generated when the timer
 155   interrupt fires.
 156
 157   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 158   @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
 159                            the timer hardware is not programmable, then EFI_UNSUPPORTED is
 160                            returned. If the timer is programmable, then the timer period
 161                            will be rounded up to the nearest timer period that is supported
 162                            by the timer hardware. If TimerPeriod is set to 0, then the
 163                            timer interrupts will be disabled.
 164
 165   @retval EFI_SUCCESS           The timer period was changed.
 166   @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
 167   @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.
 168
 169 **/
 170 EFI_STATUS
 171 EFIAPI
 172 TimerDriverSetTimerPeriod (
 173   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 174   IN UINT64                   TimerPeriod
 175   )
 176 {
 177   EFI_STATUS  Status;
 178   UINT64      TimerCount;
 179
 180   if (TimerPeriod == 0) {
 181     //
 182     // Disable interrupt 0 and timer
 183     //
 184     MmioAnd32 (TIMER_DATA, 0);
 185
 186                 Status = gInterrupt->DisableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector));
 187   } else {
 188                 //
 189                 // Convert TimerPeriod into Timer F counts
 190                 //
 191                 TimerCount = DivU64x32 (TimerPeriod + 5, 10);
 192
 193                 //
 194                 // Program Timer F with the new count value
 195                 //
 196                 MmioWrite32 (TIMER_DATA, (UINT32)TimerCount);
 197
 198                 //
 199                 // Enable interrupt and initialize and enable timer.
 200                 //
 201                 MmioOr32 (TIMER_CMD, 0x11);
 202
 203                 Status = gInterrupt->EnableInterruptSource (gInterrupt,  FixedPcdGet32 (PcdTimerVector));
 204   }
 205
 206         //
 207         // Save the new timer period
 208         //
 209         mTimerPeriod = TimerPeriod;
 210   return Status;
 211 }
 212
 213
 214 /**
 215   This function retrieves the period of timer interrupts in 100 ns units,
 216   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 217   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 218   returned, then the timer is currently disabled.
 219
 220   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 221   @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If
 222                            0 is returned, then the timer is currently disabled.
 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
 245 /**
 246   This function generates a soft timer interrupt. If the platform does not support soft
 247   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 248   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 249   service, then a soft timer interrupt will be generated. If the timer interrupt is
 250   enabled when this service is called, then the registered handler will be invoked. The
 251   registered handler should not be able to distinguish a hardware-generated timer
 252   interrupt from a software-generated timer interrupt.
 253
 254   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 255
 256   @retval EFI_SUCCESS           The soft timer interrupt was generated.
 257   @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.
 258
 259 **/
 260 EFI_STATUS
 261 EFIAPI
 262 TimerDriverGenerateSoftInterrupt (
 263   IN EFI_TIMER_ARCH_PROTOCOL  *This
 264   )
 265 {
 266   return EFI_UNSUPPORTED;
 267 }
 268
 269
 270 /**
 271   Interface stucture for the Timer Architectural Protocol.
 272
 273   @par Protocol Description:
 274   This protocol provides the services to initialize a periodic timer
 275   interrupt, and to register a handler that is called each time the timer
 276   interrupt fires.  It may also provide a service to adjust the rate of the
 277   periodic timer interrupt.  When a timer interrupt occurs, the handler is
 278   passed the amount of time that has passed since the previous timer
 279   interrupt.
 280
 281   @param RegisterHandler
 282   Registers a handler that will be called each time the
 283   timer interrupt fires.  TimerPeriod defines the minimum
 284   time between timer interrupts, so TimerPeriod will also
 285   be the minimum time between calls to the registered
 286   handler.
 287
 288   @param SetTimerPeriod
 289   Sets the period of the timer interrupt in 100 nS units.
 290   This function is optional, and may return EFI_UNSUPPORTED.
 291   If this function is supported, then the timer period will
 292   be rounded up to the nearest supported timer period.
 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
 300   registered handler if the timer interrupt has been masked for
 301   a period of time.
 302
 303 **/
 304 EFI_TIMER_ARCH_PROTOCOL   gTimer = {
 305   TimerDriverRegisterHandler,
 306   TimerDriverSetTimerPeriod,
 307   TimerDriverGetTimerPeriod,
 308   TimerDriverGenerateSoftInterrupt
 309 };
 310
 311 EFI_HANDLE  gTimerHandle = NULL;
 312
 313
 314 /**
 315   Initialize the state information for the Timer Architectural Protocol
 316
 317   @param  ImageHandle   of the loaded driver
 318   @param  SystemTable   Pointer to the System Table
 319
 320   @retval EFI_SUCCESS           Protocol registered
 321   @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
 322   @retval EFI_DEVICE_ERROR      Hardware problems
 323
 324 **/
 325 EFI_STATUS
 326 EFIAPI
 327 TimerInitialize (
 328   IN EFI_HANDLE         ImageHandle,
 329   IN EFI_SYSTEM_TABLE   *SystemTable
 330   )
 331 {
 332   EFI_STATUS  Status;
 333
 334         //
 335         // Find the interrupt controller protocol.  ASSERT if not found.
 336         //
 337         Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, ( VOID ** )&gInterrupt);
 338         ASSERT_EFI_ERROR (Status);
 339
 340   MmioWrite32 (TIMER_CMD, 0x01);
 341
 342   //
 343   // Force the timer to be disabled
 344   //
 345   Status = TimerDriverSetTimerPeriod (&gTimer, 0);
 346         ASSERT_EFI_ERROR (Status);
 347
 348   //
 349   // Install interrupt handler
 350   //
 351   Status = gInterrupt->RegisterInterruptSource (gInterrupt,  FixedPcdGet32 (PcdTimerVector), TimerInterruptHandler);
 352         ASSERT_EFI_ERROR (Status);
 353
 354         //
 355         // Force the timer to be enabled at its default period
 356         //
 357         Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32 (PcdTimerPeriod));
 358         ASSERT_EFI_ERROR (Status);
 359
 360
 361   //
 362   // Install the Timer Architectural Protocol onto a new handle
 363   //
 364   Status = gBS->InstallMultipleProtocolInterfaces (
 365                   &gTimerHandle,
 366                   &gEfiTimerArchProtocolGuid,  &gTimer,
 367                   NULL
 368                   );
 369   ASSERT_EFI_ERROR (Status);
 370
 371   return Status;
 372 }
 373