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Diffstat (limited to 'ReferenceCode/ME/Heci/Dxe/HeciHpet.c')
| -rw-r--r-- | ReferenceCode/ME/Heci/Dxe/HeciHpet.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/ReferenceCode/ME/Heci/Dxe/HeciHpet.c b/ReferenceCode/ME/Heci/Dxe/HeciHpet.c new file mode 100644 index 0000000..318757c --- /dev/null +++ b/ReferenceCode/ME/Heci/Dxe/HeciHpet.c @@ -0,0 +1,168 @@ +/** @file + Definitions for HECI driver + +@copyright + Copyright (c) 2006 - 2012 Intel Corporation. All rights reserved + This software and associated documentation (if any) is furnished + under a license and may only be used or copied in accordance + with the terms of the license. Except as permitted by such + license, no part of this software or documentation may be + reproduced, stored in a retrieval system, or transmitted in any + form or by any means without the express written consent of + Intel Corporation. + + This file contains an 'Intel Peripheral Driver' and uniquely + identified as "Intel Reference Module" and is + licensed for Intel CPUs and chipsets under the terms of your + license agreement with Intel or your vendor. This file may + be modified by the user, subject to additional terms of the + license agreement +**/ +#include "HeciDrv.h" +#include "HeciHpet.h" +#include "HeciRegs.h" +#include "HeciCore.h" + +// +// Extern for shared HECI data and protocols +// +extern HECI_INSTANCE *mHeciContext; +VOLATILE UINT32 mSaveHpetConfigReg; + +/** + Store the value of High Performance Timer + + @param[in] None + + @retval None +**/ +VOID +SaveHpet ( + VOID + ) +{ + mSaveHpetConfigReg = MmioRead32 (PCH_RCRB_BASE + R_PCH_RCRB_HPTC); +} + +/** + Restore the value of High Performance Timer + + @param[in] None + + @retval None +**/ +VOID +RestoreHpet ( + VOID + ) +{ + MmioWrite32 (PCH_RCRB_BASE + R_PCH_RCRB_HPTC, mSaveHpetConfigReg); +} + +/** + Used for calculating timeouts + + @param[out] Start Snapshot of the HPET timer + @param[out] End Calculated time when timeout period will be done + @param[in] Time Timeout period in microseconds + + @retval None +**/ +VOID +StartTimer ( + OUT UINT32 *Start, + OUT UINT32 *End, + IN UINT32 Time + ) +{ + UINT32 Ticks; + + /// + /// Make sure that HPET is enabled and running + /// + EnableHpet (); + + /// + /// Read current timer value into start time from HPET + /// + *Start = mHeciContext->HpetTimer[HPET_MAIN_COUNTER_LOW]; + + /// + /// Convert microseconds into 70ns timer ticks + /// + Ticks = Time * HPET_TICKS_PER_MICRO; + + /// + /// Compute end time + /// + *End = *Start + Ticks; + + return ; +} + +/** + Used to determine if a timeout has occured. + + @param[in] Start Snapshot of the HPET timer when the timeout period started. + @param[in] End Calculated time when timeout period will be done. + + @retval EFI_TIMEOUT Timeout occured. + @retval EFI_SUCCESS Not yet timed out +**/ +EFI_STATUS +Timeout ( + IN UINT32 Start, + IN UINT32 End + ) +{ + UINT32 Current; + + /// + /// Read HPET and assign the value as the current time. + /// + Current = mHeciContext->HpetTimer[HPET_MAIN_COUNTER_LOW]; + + /// + /// Test basic case (no overflow) + /// + if ((Start < End) && (End <= Current)) { + return EFI_TIMEOUT; + } + /// + /// Test basic start/end conditions with overflowed timer + /// + if ((Start < End) && (Current < Start)) { + return EFI_TIMEOUT; + } + /// + /// Test for overflowed start/end condition + /// + if ((Start > End) && ((Current < Start) && (Current > End))) { + return EFI_TIMEOUT; + } + /// + /// Catch corner case of broken arguments + /// + if (Start == End) { + return EFI_TIMEOUT; + } + /// + /// Else, we have not yet timed out + /// + return EFI_SUCCESS; +} + +/** + Delay for at least the request number of microseconds + + @param[in] delayTime Number of microseconds to delay. + + @retval None +**/ +VOID +IoDelay ( + IN UINT32 delayTime + ) +{ + gBS->Stall (delayTime); +} |