EdkUnixPkg/Dxe/UnixThunk/Chipset/Timer/Timer.c

   1 /*++
   2
   3 Copyright (c) 2004, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   Timer.c
  15
  16 Abstract:
  17
  18   UNIX Emulation Timer Architectural Protocol Driver as defined in DXE CIS
  19
  20   This Timer module uses an UNIX Thread to simulate the timer-tick driven
  21   timer service.  In the future, the Thread creation should possibly be
  22   abstracted by the CPU architectural protocol
  23
  24 --*/
  25
  26 #include "Timer.h"
  27
  28 //
  29 // Pointer to the CPU Architectural Protocol instance
  30 //
  31 EFI_CPU_ARCH_PROTOCOL   *mCpu;
  32
  33 //
  34 // The Timer Architectural Protocol that this driver produces
  35 //
  36 EFI_TIMER_ARCH_PROTOCOL mTimer = {
  37   UnixTimerDriverRegisterHandler,
  38   UnixTimerDriverSetTimerPeriod,
  39   UnixTimerDriverGetTimerPeriod,
  40   UnixTimerDriverGenerateSoftInterrupt
  41 };
  42
  43 //
  44 // The notification function to call on every timer interrupt
  45 //
  46 EFI_TIMER_NOTIFY        mTimerNotifyFunction = NULL;
  47
  48 //
  49 // The current period of the timer interrupt
  50 //
  51 UINT64                  mTimerPeriod;
  52
  53 //
  54 // The timer value from the last timer interrupt
  55 //
  56 UINT32                  mNtLastTick;
  57
  58 VOID
  59 TimerCallback (UINT64 DeltaMs)
  60 /*++
  61
  62 Routine Description:
  63
  64   TODO: Add function description
  65
  66 Arguments:
  67
  68   wTimerID  - TODO: add argument description
  69   msg       - TODO: add argument description
  70   dwUser    - TODO: add argument description
  71   dw1       - TODO: add argument description
  72   dw2       - TODO: add argument description
  73
  74 Returns:
  75
  76   TODO: add return values
  77
  78 --*/
  79 {
  80   EFI_TPL           OriginalTPL;
  81   EFI_TIMER_NOTIFY  CallbackFunction;
  82
  83
  84   OriginalTPL = gBS->RaiseTPL (EFI_TPL_HIGH_LEVEL);
  85
  86   CallbackFunction = mTimerNotifyFunction;
  87
  88   //
  89   // Only invoke the callback function if a Non-NULL handler has been
  90   // registered. Assume all other handlers are legal.
  91   //
  92   if (CallbackFunction != NULL) {
  93     CallbackFunction ((UINT64) (DeltaMs * 10000));
  94   }
  95
  96   gBS->RestoreTPL (OriginalTPL);
  97
  98 }
  99
 100 EFI_STATUS
 101 EFIAPI
 102 UnixTimerDriverRegisterHandler (
 103   IN EFI_TIMER_ARCH_PROTOCOL           *This,
 104   IN EFI_TIMER_NOTIFY                  NotifyFunction
 105   )
 106 /*++
 107
 108 Routine Description:
 109
 110   This function registers the handler NotifyFunction so it is called every time
 111   the timer interrupt fires.  It also passes the amount of time since the last
 112   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
 113   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
 114   returned.  If the CPU does not support registering a timer interrupt handler,
 115   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
 116   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
 117   If an attempt is made to unregister a handler when a handler is not registered,
 118   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
 119   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
 120   is returned.
 121
 122 Arguments:
 123
 124   This           - The EFI_TIMER_ARCH_PROTOCOL instance.
 125
 126   NotifyFunction - The function to call when a timer interrupt fires.  This
 127                    function executes at TPL_HIGH_LEVEL.  The DXE Core will
 128                    register a handler for the timer interrupt, so it can know
 129                    how much time has passed.  This information is used to
 130                    signal timer based events.  NULL will unregister the handler.
 131
 132 Returns:
 133
 134   EFI_SUCCESS           - The timer handler was registered.
 135
 136   EFI_UNSUPPORTED       - The platform does not support timer interrupts.
 137
 138   EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already
 139                           registered.
 140
 141   EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
 142                           previously registered.
 143
 144   EFI_DEVICE_ERROR      - The timer handler could not be registered.
 145
 146 --*/
 147 {
 148   //
 149   // Check for invalid parameters
 150   //
 151   if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
 152     return EFI_INVALID_PARAMETER;
 153   }
 154
 155   if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
 156     return EFI_ALREADY_STARTED;
 157   }
 158
 159   if (NotifyFunction == NULL) {
 160     /* Disable timer.  */
 161     gUnix->SetTimer (0, TimerCallback);
 162   } else if (mTimerNotifyFunction == NULL) {
 163     /* Enable Timer.  */
 164     gUnix->SetTimer (mTimerPeriod * 10, TimerCallback);
 165   }
 166   mTimerNotifyFunction = NotifyFunction;
 167
 168   return EFI_SUCCESS;
 169 }
 170
 171 EFI_STATUS
 172 EFIAPI
 173 UnixTimerDriverSetTimerPeriod (
 174   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 175   IN UINT64                   TimerPeriod
 176   )
 177 /*++
 178
 179 Routine Description:
 180
 181   This function adjusts the period of timer interrupts to the value specified
 182   by TimerPeriod.  If the timer period is updated, then the selected timer
 183   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 184   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 185   If an error occurs while attempting to update the timer period, then the
 186   timer hardware will be put back in its state prior to this call, and
 187   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 188   is disabled.  This is not the same as disabling the CPU's interrupts.
 189   Instead, it must either turn off the timer hardware, or it must adjust the
 190   interrupt controller so that a CPU interrupt is not generated when the timer
 191   interrupt fires.
 192
 193 Arguments:
 194
 195   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 196
 197   TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If
 198                 the timer hardware is not programmable, then EFI_UNSUPPORTED is
 199                 returned.  If the timer is programmable, then the timer period
 200                 will be rounded up to the nearest timer period that is supported
 201                 by the timer hardware.  If TimerPeriod is set to 0, then the
 202                 timer interrupts will be disabled.
 203
 204 Returns:
 205
 206   EFI_SUCCESS      - The timer period was changed.
 207
 208   EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.
 209
 210   EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.
 211
 212 --*/
 213 {
 214
 215   //
 216   // If TimerPeriod is 0, then the timer thread should be canceled
 217   // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread
 218   //
 219   if (TimerPeriod == 0
 220       || ((TimerPeriod > TIMER_MINIMUM_VALUE)
 221           && (TimerPeriod < TIMER_MAXIMUM_VALUE))) {
 222     mTimerPeriod = TimerPeriod;
 223
 224     gUnix->SetTimer (TimerPeriod * 10, TimerCallback);
 225   }
 226
 227   return EFI_SUCCESS;
 228 }
 229
 230 EFI_STATUS
 231 EFIAPI
 232 UnixTimerDriverGetTimerPeriod (
 233   IN EFI_TIMER_ARCH_PROTOCOL            *This,
 234   OUT UINT64                            *TimerPeriod
 235   )
 236 /*++
 237
 238 Routine Description:
 239
 240   This function retrieves the period of timer interrupts in 100 ns units,
 241   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 242   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 243   returned, then the timer is currently disabled.
 244
 245 Arguments:
 246
 247   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 248
 249   TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If
 250                 0 is returned, then the timer is currently disabled.
 251
 252 Returns:
 253
 254   EFI_SUCCESS           - The timer period was returned in TimerPeriod.
 255
 256   EFI_INVALID_PARAMETER - TimerPeriod is NULL.
 257
 258 --*/
 259 {
 260   if (TimerPeriod == NULL) {
 261     return EFI_INVALID_PARAMETER;
 262   }
 263
 264   *TimerPeriod = mTimerPeriod;
 265
 266   return EFI_SUCCESS;
 267 }
 268
 269 EFI_STATUS
 270 EFIAPI
 271 UnixTimerDriverGenerateSoftInterrupt (
 272   IN EFI_TIMER_ARCH_PROTOCOL  *This
 273   )
 274 /*++
 275
 276 Routine Description:
 277
 278   This function generates a soft timer interrupt. If the platform does not support soft
 279   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 280   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 281   service, then a soft timer interrupt will be generated. If the timer interrupt is
 282   enabled when this service is called, then the registered handler will be invoked. The
 283   registered handler should not be able to distinguish a hardware-generated timer
 284   interrupt from a software-generated timer interrupt.
 285
 286 Arguments:
 287
 288   This  -  The EFI_TIMER_ARCH_PROTOCOL instance.
 289
 290 Returns:
 291
 292   EFI_SUCCESS       - The soft timer interrupt was generated.
 293
 294   EFI_UNSUPPORTEDT  - The platform does not support the generation of soft timer interrupts.
 295
 296 --*/
 297 {
 298   return EFI_UNSUPPORTED;
 299 }
 300
 301 EFI_STATUS
 302 EFIAPI
 303 UnixTimerDriverInitialize (
 304   IN EFI_HANDLE        ImageHandle,
 305   IN EFI_SYSTEM_TABLE  *SystemTable
 306   )
 307 /*++
 308
 309 Routine Description:
 310
 311   Initialize the Timer Architectural Protocol driver
 312
 313 Arguments:
 314
 315   ImageHandle - ImageHandle of the loaded driver
 316
 317   SystemTable - Pointer to the System Table
 318
 319 Returns:
 320
 321   EFI_SUCCESS           - Timer Architectural Protocol created
 322
 323   EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.
 324
 325   EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.
 326
 327 --*/
 328 {
 329   EFI_STATUS  Status;
 330   EFI_HANDLE  Handle;
 331
 332   //
 333   // Make sure the Timer Architectural Protocol is not already installed in the system
 334   //
 335   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);
 336
 337   //
 338   // Get the CPU Architectural Protocol instance
 339   //
 340   Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu);
 341   ASSERT_EFI_ERROR (Status);
 342
 343   //
 344   // Install the Timer Architectural Protocol onto a new handle
 345   //
 346   Handle = NULL;
 347   Status = gBS->InstallProtocolInterface (
 348                   &Handle,
 349                   &gEfiTimerArchProtocolGuid,
 350                   EFI_NATIVE_INTERFACE,
 351                   &mTimer
 352                   );
 353   if (EFI_ERROR (Status)) {
 354     return Status;
 355   }
 356
 357   return EFI_SUCCESS;
 358 }