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1e57a462 | 1 | /** @file\r |
2 | *\r | |
b2ce4a39 | 3 | * Copyright (c) 2011-2013, ARM Limited. All rights reserved.\r |
e3fa3d83 | 4 | * Copyright (c) 2018, Linaro Limited. All rights reserved.\r |
1e57a462 | 5 | *\r |
6 | * This program and the accompanying materials\r | |
7 | * are licensed and made available under the terms and conditions of the BSD License\r | |
8 | * which accompanies this distribution. The full text of the license may be found at\r | |
9 | * http://opensource.org/licenses/bsd-license.php\r | |
10 | *\r | |
11 | * THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
12 | * WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
13 | *\r | |
14 | **/\r | |
15 | \r | |
16 | \r | |
17 | #include <PiDxe.h>\r | |
18 | \r | |
19 | #include <Library/BaseLib.h>\r | |
20 | #include <Library/BaseMemoryLib.h>\r | |
21 | #include <Library/DebugLib.h>\r | |
22 | #include <Library/IoLib.h>\r | |
1e57a462 | 23 | #include <Library/UefiBootServicesTableLib.h>\r |
5afabd5e | 24 | #include <Library/UefiRuntimeServicesTableLib.h>\r |
1e57a462 | 25 | \r |
5afabd5e | 26 | #include <Protocol/HardwareInterrupt.h>\r |
1e57a462 | 27 | #include <Protocol/WatchdogTimer.h>\r |
b9fddfb8 AB |
28 | \r |
29 | #include "SP805Watchdog.h"\r | |
1e57a462 | 30 | \r |
5afabd5e AB |
31 | STATIC EFI_EVENT mEfiExitBootServicesEvent;\r |
32 | STATIC EFI_HARDWARE_INTERRUPT_PROTOCOL *mInterrupt;\r | |
33 | STATIC EFI_WATCHDOG_TIMER_NOTIFY mWatchdogNotify;\r | |
34 | STATIC UINT32 mTimerPeriod;\r | |
1e57a462 | 35 | \r |
36 | /**\r | |
37 | Make sure the SP805 registers are unlocked for writing.\r | |
38 | \r | |
39 | Note: The SP805 Watchdog Timer supports locking of its registers,\r | |
40 | i.e. it inhibits all writes to avoid rogue software accidentally\r | |
41 | corrupting their contents.\r | |
42 | **/\r | |
b2ce4a39 | 43 | STATIC\r |
1e57a462 | 44 | VOID\r |
45 | SP805Unlock (\r | |
46 | VOID\r | |
47 | )\r | |
48 | {\r | |
e3fa3d83 AB |
49 | if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_LOCKED) {\r |
50 | MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_SPECIAL_UNLOCK_CODE);\r | |
1e57a462 | 51 | }\r |
52 | }\r | |
53 | \r | |
54 | /**\r | |
55 | Make sure the SP805 registers are locked and can not be overwritten.\r | |
56 | \r | |
57 | Note: The SP805 Watchdog Timer supports locking of its registers,\r | |
58 | i.e. it inhibits all writes to avoid rogue software accidentally\r | |
59 | corrupting their contents.\r | |
60 | **/\r | |
b2ce4a39 | 61 | STATIC\r |
1e57a462 | 62 | VOID\r |
63 | SP805Lock (\r | |
64 | VOID\r | |
65 | )\r | |
66 | {\r | |
e3fa3d83 | 67 | if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_UNLOCKED) {\r |
1e57a462 | 68 | // To lock it, just write in any number (except the special unlock code).\r |
e3fa3d83 | 69 | MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_LOCK_IS_LOCKED);\r |
1e57a462 | 70 | }\r |
71 | }\r | |
72 | \r | |
5afabd5e AB |
73 | STATIC\r |
74 | VOID\r | |
75 | EFIAPI\r | |
76 | SP805InterruptHandler (\r | |
77 | IN HARDWARE_INTERRUPT_SOURCE Source,\r | |
78 | IN EFI_SYSTEM_CONTEXT SystemContext\r | |
79 | )\r | |
80 | {\r | |
81 | SP805Unlock ();\r | |
82 | MmioWrite32 (SP805_WDOG_INT_CLR_REG, 0); // write of any value clears the irq\r | |
83 | SP805Lock ();\r | |
84 | \r | |
85 | mInterrupt->EndOfInterrupt (mInterrupt, Source);\r | |
86 | \r | |
87 | //\r | |
88 | // The notify function should be called with the elapsed number of ticks\r | |
89 | // since the watchdog was armed, which should exceed the timer period.\r | |
90 | // We don't actually know the elapsed number of ticks, so let's return\r | |
91 | // the timer period plus 1.\r | |
92 | //\r | |
93 | if (mWatchdogNotify != NULL) {\r | |
94 | mWatchdogNotify (mTimerPeriod + 1);\r | |
95 | }\r | |
96 | \r | |
97 | gRT->ResetSystem (EfiResetCold, EFI_TIMEOUT, 0, NULL);\r | |
98 | }\r | |
99 | \r | |
1e57a462 | 100 | /**\r |
101 | Stop the SP805 watchdog timer from counting down by disabling interrupts.\r | |
102 | **/\r | |
b2ce4a39 | 103 | STATIC\r |
1e57a462 | 104 | VOID\r |
105 | SP805Stop (\r | |
106 | VOID\r | |
107 | )\r | |
108 | {\r | |
109 | // Disable interrupts\r | |
e3fa3d83 AB |
110 | if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) != 0) {\r |
111 | MmioAnd32 (SP805_WDOG_CONTROL_REG, ~SP805_WDOG_CTRL_INTEN);\r | |
1e57a462 | 112 | }\r |
113 | }\r | |
114 | \r | |
115 | /**\r | |
116 | Starts the SP805 counting down by enabling interrupts.\r | |
117 | The count down will start from the value stored in the Load register,\r | |
118 | not from the value where it was previously stopped.\r | |
119 | **/\r | |
b2ce4a39 | 120 | STATIC\r |
1e57a462 | 121 | VOID\r |
122 | SP805Start (\r | |
123 | VOID\r | |
124 | )\r | |
125 | {\r | |
126 | // Enable interrupts\r | |
e3fa3d83 AB |
127 | if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0) {\r |
128 | MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_INTEN);\r | |
1e57a462 | 129 | }\r |
130 | }\r | |
131 | \r | |
132 | /**\r | |
133 | On exiting boot services we must make sure the SP805 Watchdog Timer\r | |
134 | is stopped.\r | |
135 | **/\r | |
e3fa3d83 | 136 | STATIC\r |
1e57a462 | 137 | VOID\r |
138 | EFIAPI\r | |
139 | ExitBootServicesEvent (\r | |
140 | IN EFI_EVENT Event,\r | |
141 | IN VOID *Context\r | |
142 | )\r | |
143 | {\r | |
e3fa3d83 AB |
144 | SP805Unlock ();\r |
145 | SP805Stop ();\r | |
146 | SP805Lock ();\r | |
1e57a462 | 147 | }\r |
148 | \r | |
149 | /**\r | |
150 | This function registers the handler NotifyFunction so it is called every time\r | |
151 | the watchdog timer expires. It also passes the amount of time since the last\r | |
152 | handler call to the NotifyFunction.\r | |
153 | If NotifyFunction is not NULL and a handler is not already registered,\r | |
154 | then the new handler is registered and EFI_SUCCESS is returned.\r | |
155 | If NotifyFunction is NULL, and a handler is already registered,\r | |
156 | then that handler is unregistered.\r | |
157 | If an attempt is made to register a handler when a handler is already registered,\r | |
158 | then EFI_ALREADY_STARTED is returned.\r | |
159 | If an attempt is made to unregister a handler when a handler is not registered,\r | |
160 | then EFI_INVALID_PARAMETER is returned.\r | |
161 | \r | |
162 | @param This The EFI_TIMER_ARCH_PROTOCOL instance.\r | |
163 | @param NotifyFunction The function to call when a timer interrupt fires. This\r | |
164 | function executes at TPL_HIGH_LEVEL. The DXE Core will\r | |
165 | register a handler for the timer interrupt, so it can know\r | |
166 | how much time has passed. This information is used to\r | |
167 | signal timer based events. NULL will unregister the handler.\r | |
168 | \r | |
169 | @retval EFI_SUCCESS The watchdog timer handler was registered.\r | |
170 | @retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already\r | |
171 | registered.\r | |
172 | @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not\r | |
173 | previously registered.\r | |
174 | \r | |
175 | **/\r | |
e3fa3d83 | 176 | STATIC\r |
1e57a462 | 177 | EFI_STATUS\r |
178 | EFIAPI\r | |
179 | SP805RegisterHandler (\r | |
e3fa3d83 | 180 | IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,\r |
1e57a462 | 181 | IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction\r |
182 | )\r | |
183 | {\r | |
5afabd5e AB |
184 | if (mWatchdogNotify == NULL && NotifyFunction == NULL) {\r |
185 | return EFI_INVALID_PARAMETER;\r | |
186 | }\r | |
187 | \r | |
188 | if (mWatchdogNotify != NULL && NotifyFunction != NULL) {\r | |
189 | return EFI_ALREADY_STARTED;\r | |
190 | }\r | |
191 | \r | |
192 | mWatchdogNotify = NotifyFunction;\r | |
193 | return EFI_SUCCESS;\r | |
1e57a462 | 194 | }\r |
195 | \r | |
196 | /**\r | |
197 | \r | |
198 | This function adjusts the period of timer interrupts to the value specified\r | |
199 | by TimerPeriod. If the timer period is updated, then the selected timer\r | |
200 | period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If\r | |
201 | the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.\r | |
202 | If an error occurs while attempting to update the timer period, then the\r | |
203 | timer hardware will be put back in its state prior to this call, and\r | |
204 | EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt\r | |
205 | is disabled. This is not the same as disabling the CPU's interrupts.\r | |
206 | Instead, it must either turn off the timer hardware, or it must adjust the\r | |
207 | interrupt controller so that a CPU interrupt is not generated when the timer\r | |
208 | interrupt fires.\r | |
209 | \r | |
210 | @param This The EFI_TIMER_ARCH_PROTOCOL instance.\r | |
211 | @param TimerPeriod The rate to program the timer interrupt in 100 nS units. If\r | |
212 | the timer hardware is not programmable, then EFI_UNSUPPORTED is\r | |
213 | returned. If the timer is programmable, then the timer period\r | |
214 | will be rounded up to the nearest timer period that is supported\r | |
215 | by the timer hardware. If TimerPeriod is set to 0, then the\r | |
216 | timer interrupts will be disabled.\r | |
217 | \r | |
218 | \r | |
219 | @retval EFI_SUCCESS The timer period was changed.\r | |
220 | @retval EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt.\r | |
221 | @retval EFI_DEVICE_ERROR The timer period could not be changed due to a device error.\r | |
222 | \r | |
223 | **/\r | |
e3fa3d83 | 224 | STATIC\r |
1e57a462 | 225 | EFI_STATUS\r |
226 | EFIAPI\r | |
227 | SP805SetTimerPeriod (\r | |
e3fa3d83 | 228 | IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,\r |
1e57a462 | 229 | IN UINT64 TimerPeriod // In 100ns units\r |
230 | )\r | |
231 | {\r | |
e3fa3d83 | 232 | EFI_STATUS Status;\r |
1e57a462 | 233 | UINT64 Ticks64bit;\r |
234 | \r | |
e3fa3d83 | 235 | SP805Unlock ();\r |
1e57a462 | 236 | \r |
e3fa3d83 AB |
237 | Status = EFI_SUCCESS;\r |
238 | \r | |
239 | if (TimerPeriod == 0) {\r | |
1e57a462 | 240 | // This is a watchdog stop request\r |
e3fa3d83 | 241 | SP805Stop ();\r |
1e57a462 | 242 | } else {\r |
243 | // Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds\r | |
5afabd5e | 244 | // The SP805 will count down to zero and generate an interrupt.\r |
1e57a462 | 245 | //\r |
5afabd5e | 246 | // WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz);\r |
1e57a462 | 247 | //\r |
248 | // i.e.:\r | |
249 | //\r | |
5afabd5e | 250 | // WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 10 MHz ;\r |
1e57a462 | 251 | \r |
e3fa3d83 | 252 | Ticks64bit = MultU64x32 (TimerPeriod, PcdGet32 (PcdSP805WatchdogClockFrequencyInHz));\r |
5afabd5e | 253 | Ticks64bit = DivU64x32 (Ticks64bit, 10 * 1000 * 1000);\r |
1e57a462 | 254 | \r |
255 | // The registers in the SP805 are only 32 bits\r | |
e3fa3d83 | 256 | if (Ticks64bit > MAX_UINT32) {\r |
1e57a462 | 257 | // We could load the watchdog with the maximum supported value but\r |
258 | // if a smaller value was requested, this could have the watchdog\r | |
259 | // triggering before it was intended.\r | |
260 | // Better generate an error to let the caller know.\r | |
261 | Status = EFI_DEVICE_ERROR;\r | |
262 | goto EXIT;\r | |
263 | }\r | |
264 | \r | |
265 | // Update the watchdog with a 32-bit value.\r | |
e3fa3d83 | 266 | MmioWrite32 (SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);\r |
1e57a462 | 267 | \r |
268 | // Start the watchdog\r | |
e3fa3d83 | 269 | SP805Start ();\r |
1e57a462 | 270 | }\r |
271 | \r | |
5afabd5e AB |
272 | mTimerPeriod = TimerPeriod;\r |
273 | \r | |
e3fa3d83 | 274 | EXIT:\r |
1e57a462 | 275 | // Ensure the watchdog is locked before exiting.\r |
e3fa3d83 | 276 | SP805Lock ();\r |
5afabd5e | 277 | ASSERT_EFI_ERROR (Status);\r |
1e57a462 | 278 | return Status;\r |
279 | }\r | |
280 | \r | |
281 | /**\r | |
282 | This function retrieves the period of timer interrupts in 100 ns units,\r | |
283 | returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod\r | |
284 | is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is\r | |
285 | returned, then the timer is currently disabled.\r | |
286 | \r | |
287 | @param This The EFI_TIMER_ARCH_PROTOCOL instance.\r | |
288 | @param TimerPeriod A pointer to the timer period to retrieve in 100 ns units. If\r | |
289 | 0 is returned, then the timer is currently disabled.\r | |
290 | \r | |
291 | \r | |
292 | @retval EFI_SUCCESS The timer period was returned in TimerPeriod.\r | |
293 | @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.\r | |
294 | \r | |
295 | **/\r | |
e3fa3d83 | 296 | STATIC\r |
1e57a462 | 297 | EFI_STATUS\r |
298 | EFIAPI\r | |
299 | SP805GetTimerPeriod (\r | |
e3fa3d83 | 300 | IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,\r |
1e57a462 | 301 | OUT UINT64 *TimerPeriod\r |
302 | )\r | |
303 | {\r | |
1e57a462 | 304 | if (TimerPeriod == NULL) {\r |
305 | return EFI_INVALID_PARAMETER;\r | |
306 | }\r | |
307 | \r | |
5afabd5e | 308 | *TimerPeriod = mTimerPeriod;\r |
e3fa3d83 | 309 | return EFI_SUCCESS;\r |
1e57a462 | 310 | }\r |
311 | \r | |
312 | /**\r | |
313 | Interface structure for the Watchdog Architectural Protocol.\r | |
314 | \r | |
315 | @par Protocol Description:\r | |
316 | This protocol provides a service to set the amount of time to wait\r | |
317 | before firing the watchdog timer, and it also provides a service to\r | |
318 | register a handler that is invoked when the watchdog timer fires.\r | |
319 | \r | |
320 | @par When the watchdog timer fires, control will be passed to a handler\r | |
321 | if one has been registered. If no handler has been registered,\r | |
322 | or the registered handler returns, then the system will be\r | |
323 | reset by calling the Runtime Service ResetSystem().\r | |
324 | \r | |
325 | @param RegisterHandler\r | |
326 | Registers a handler that will be called each time the\r | |
327 | watchdogtimer interrupt fires. TimerPeriod defines the minimum\r | |
328 | time between timer interrupts, so TimerPeriod will also\r | |
329 | be the minimum time between calls to the registered\r | |
330 | handler.\r | |
331 | NOTE: If the watchdog resets the system in hardware, then\r | |
332 | this function will not have any chance of executing.\r | |
333 | \r | |
334 | @param SetTimerPeriod\r | |
335 | Sets the period of the timer interrupt in 100 nS units.\r | |
336 | This function is optional, and may return EFI_UNSUPPORTED.\r | |
337 | If this function is supported, then the timer period will\r | |
338 | be rounded up to the nearest supported timer period.\r | |
339 | \r | |
340 | @param GetTimerPeriod\r | |
341 | Retrieves the period of the timer interrupt in 100 nS units.\r | |
342 | \r | |
343 | **/\r | |
e3fa3d83 AB |
344 | STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer = {\r |
345 | SP805RegisterHandler,\r | |
346 | SP805SetTimerPeriod,\r | |
347 | SP805GetTimerPeriod\r | |
1e57a462 | 348 | };\r |
349 | \r | |
350 | /**\r | |
351 | Initialize the state information for the Watchdog Timer Architectural Protocol.\r | |
352 | \r | |
353 | @param ImageHandle of the loaded driver\r | |
354 | @param SystemTable Pointer to the System Table\r | |
355 | \r | |
356 | @retval EFI_SUCCESS Protocol registered\r | |
357 | @retval EFI_OUT_OF_RESOURCES Cannot allocate protocol data structure\r | |
358 | @retval EFI_DEVICE_ERROR Hardware problems\r | |
359 | \r | |
360 | **/\r | |
361 | EFI_STATUS\r | |
362 | EFIAPI\r | |
363 | SP805Initialize (\r | |
364 | IN EFI_HANDLE ImageHandle,\r | |
365 | IN EFI_SYSTEM_TABLE *SystemTable\r | |
366 | )\r | |
367 | {\r | |
368 | EFI_STATUS Status;\r | |
369 | EFI_HANDLE Handle;\r | |
370 | \r | |
5afabd5e AB |
371 | // Find the interrupt controller protocol. ASSERT if not found.\r |
372 | Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL,\r | |
373 | (VOID **)&mInterrupt);\r | |
374 | ASSERT_EFI_ERROR (Status);\r | |
375 | \r | |
1e57a462 | 376 | // Unlock access to the SP805 registers\r |
377 | SP805Unlock ();\r | |
378 | \r | |
379 | // Stop the watchdog from triggering unexpectedly\r | |
380 | SP805Stop ();\r | |
381 | \r | |
382 | // Set the watchdog to reset the board when triggered\r | |
5afabd5e | 383 | // This is a last resort in case the interrupt handler fails\r |
e3fa3d83 | 384 | if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_RESEN) == 0) {\r |
1e57a462 | 385 | MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_RESEN);\r |
386 | }\r | |
387 | \r | |
5afabd5e AB |
388 | // Clear any pending interrupts\r |
389 | MmioWrite32 (SP805_WDOG_INT_CLR_REG, 0); // write of any value clears the irq\r | |
390 | \r | |
1e57a462 | 391 | // Prohibit any rogue access to SP805 registers\r |
e3fa3d83 | 392 | SP805Lock ();\r |
3402aac7 | 393 | \r |
5afabd5e AB |
394 | if (PcdGet32 (PcdSP805WatchdogInterrupt) > 0) {\r |
395 | Status = mInterrupt->RegisterInterruptSource (mInterrupt,\r | |
396 | PcdGet32 (PcdSP805WatchdogInterrupt),\r | |
397 | SP805InterruptHandler);\r | |
398 | if (EFI_ERROR (Status)) {\r | |
399 | DEBUG ((DEBUG_ERROR, "%a: failed to register watchdog interrupt - %r\n",\r | |
400 | __FUNCTION__, Status));\r | |
401 | return Status;\r | |
402 | }\r | |
403 | } else {\r | |
404 | DEBUG ((DEBUG_WARN, "%a: no interrupt specified, running in RESET mode only\n",\r | |
405 | __FUNCTION__));\r | |
406 | }\r | |
407 | \r | |
1e57a462 | 408 | //\r |
409 | // Make sure the Watchdog Timer Architectural Protocol has not been installed in the system yet.\r | |
410 | // This will avoid conflicts with the universal watchdog\r | |
411 | //\r | |
412 | ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid);\r | |
413 | \r | |
414 | // Register for an ExitBootServicesEvent\r | |
e3fa3d83 AB |
415 | Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY,\r |
416 | ExitBootServicesEvent, NULL, &mEfiExitBootServicesEvent);\r | |
417 | if (EFI_ERROR (Status)) {\r | |
1e57a462 | 418 | Status = EFI_OUT_OF_RESOURCES;\r |
419 | goto EXIT;\r | |
420 | }\r | |
421 | \r | |
422 | // Install the Timer Architectural Protocol onto a new handle\r | |
423 | Handle = NULL;\r | |
e3fa3d83 | 424 | Status = gBS->InstallMultipleProtocolInterfaces (\r |
1e57a462 | 425 | &Handle,\r |
e3fa3d83 | 426 | &gEfiWatchdogTimerArchProtocolGuid, &mWatchdogTimer,\r |
1e57a462 | 427 | NULL\r |
428 | );\r | |
e3fa3d83 | 429 | if (EFI_ERROR (Status)) {\r |
1e57a462 | 430 | Status = EFI_OUT_OF_RESOURCES;\r |
431 | goto EXIT;\r | |
432 | }\r | |
433 | \r | |
434 | EXIT:\r | |
e3fa3d83 | 435 | ASSERT_EFI_ERROR (Status);\r |
1e57a462 | 436 | return Status;\r |
437 | }\r |