ArmPlatformPkg/Library/PL031RealTimeClockLib/PL031RealTimeClockLib.c
/** @file
Implement EFI RealTimeClock runtime services via RTC Lib.
Currently this driver does not support runtime virtual calling.
Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
Copyright (c) 2011-2013, ARM Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Uefi.h>
#include <PiDxe.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/UefiLib.h>
#include <Library/IoLib.h>
#include <Library/RealTimeClockLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/PcdLib.h>
#include <Library/ArmPlatformSysConfigLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Protocol/RealTimeClock.h>
#include <Guid/GlobalVariable.h>
#include <Drivers/PL031RealTimeClock.h>
#include <ArmPlatform.h>
STATIC CONST CHAR16 mTimeZoneVariableName[] = L"PL031RtcTimeZone";
STATIC CONST CHAR16 mDaylightVariableName[] = L"PL031RtcDaylight";
STATIC BOOLEAN mPL031Initialized = FALSE;
EFI_STATUS
IdentifyPL031 (
VOID
)
{
EFI_STATUS Status;
// Check if this is a PrimeCell Peripheral
if ( (MmioRead8 (PL031_RTC_PCELL_ID0) != 0x0D)
|| (MmioRead8 (PL031_RTC_PCELL_ID1) != 0xF0)
|| (MmioRead8 (PL031_RTC_PCELL_ID2) != 0x05)
|| (MmioRead8 (PL031_RTC_PCELL_ID3) != 0xB1)) {
Status = EFI_NOT_FOUND;
goto EXIT;
}
// Check if this PrimeCell Peripheral is the PL031 Real Time Clock
if ( (MmioRead8 (PL031_RTC_PERIPH_ID0) != 0x31)
|| (MmioRead8 (PL031_RTC_PERIPH_ID1) != 0x10)
|| ((MmioRead8 (PL031_RTC_PERIPH_ID2) & 0xF) != 0x04)
|| (MmioRead8 (PL031_RTC_PERIPH_ID3) != 0x00)) {
Status = EFI_NOT_FOUND;
goto EXIT;
}
Status = EFI_SUCCESS;
EXIT:
return Status;
}
EFI_STATUS
InitializePL031 (
VOID
)
{
EFI_STATUS Status;
// Prepare the hardware
Status = IdentifyPL031();
if (EFI_ERROR (Status)) {
goto EXIT;
}
// Ensure interrupts are masked. We do not want RTC interrupts in UEFI
if ((MmioRead32 (PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER) & PL031_SET_IRQ_MASK) != PL031_SET_IRQ_MASK) {
MmioOr32 (PL031_RTC_IMSC_IRQ_MASK_SET_CLEAR_REGISTER, PL031_SET_IRQ_MASK);
}
// Clear any existing interrupts
if ((MmioRead32 (PL031_RTC_RIS_RAW_IRQ_STATUS_REGISTER) & PL031_IRQ_TRIGGERED) == PL031_IRQ_TRIGGERED) {
MmioOr32 (PL031_RTC_ICR_IRQ_CLEAR_REGISTER, PL031_CLEAR_IRQ);
}
// Start the clock counter
if ((MmioRead32 (PL031_RTC_CR_CONTROL_REGISTER) & PL031_RTC_ENABLED) != PL031_RTC_ENABLED) {
MmioOr32 (PL031_RTC_CR_CONTROL_REGISTER, PL031_RTC_ENABLED);
}
mPL031Initialized = TRUE;
EXIT:
return Status;
}
/**
Converts Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC) to EFI_TIME
**/
VOID
EpochToEfiTime (
IN UINTN EpochSeconds,
OUT EFI_TIME *Time
)
{
UINTN a;
UINTN b;
UINTN c;
UINTN d;
UINTN g;
UINTN j;
UINTN m;
UINTN y;
UINTN da;
UINTN db;
UINTN dc;
UINTN dg;
UINTN hh;
UINTN mm;
UINTN ss;
UINTN J;
J = (EpochSeconds / 86400) + 2440588;
j = J + 32044;
g = j / 146097;
dg = j % 146097;
c = (((dg / 36524) + 1) * 3) / 4;
dc = dg - (c * 36524);
b = dc / 1461;
db = dc % 1461;
a = (((db / 365) + 1) * 3) / 4;
da = db - (a * 365);
y = (g * 400) + (c * 100) + (b * 4) + a;
m = (((da * 5) + 308) / 153) - 2;
d = da - (((m + 4) * 153) / 5) + 122;
Time->Year = y - 4800 + ((m + 2) / 12);
Time->Month = ((m + 2) % 12) + 1;
Time->Day = d + 1;
ss = EpochSeconds % 60;
a = (EpochSeconds - ss) / 60;
mm = a % 60;
b = (a - mm) / 60;
hh = b % 24;
Time->Hour = hh;
Time->Minute = mm;
Time->Second = ss;
Time->Nanosecond = 0;
}
/**
Converts EFI_TIME to Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC)
**/
UINTN
EfiTimeToEpoch (
IN EFI_TIME *Time
)
{
UINTN a;
UINTN y;
UINTN m;
UINTN JulianDate; // Absolute Julian Date representation of the supplied Time
UINTN EpochDays; // Number of days elapsed since EPOCH_JULIAN_DAY
UINTN EpochSeconds;
a = (14 - Time->Month) / 12 ;
y = Time->Year + 4800 - a;
m = Time->Month + (12*a) - 3;
JulianDate = Time->Day + ((153*m + 2)/5) + (365*y) + (y/4) - (y/100) + (y/400) - 32045;
ASSERT (JulianDate >= EPOCH_JULIAN_DATE);
EpochDays = JulianDate - EPOCH_JULIAN_DATE;
EpochSeconds = (EpochDays * SEC_PER_DAY) + ((UINTN)Time->Hour * SEC_PER_HOUR) + (Time->Minute * SEC_PER_MIN) + Time->Second;
return EpochSeconds;
}
BOOLEAN
IsLeapYear (
IN EFI_TIME *Time
)
{
if (Time->Year % 4 == 0) {
if (Time->Year % 100 == 0) {
if (Time->Year % 400 == 0) {
return TRUE;
} else {
return FALSE;
}
} else {
return TRUE;
}
} else {
return FALSE;
}
}
BOOLEAN
DayValid (
IN EFI_TIME *Time
)
{
INTN DayOfMonth[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
if (Time->Day < 1 ||
Time->Day > DayOfMonth[Time->Month - 1] ||
(Time->Month == 2 && (!IsLeapYear (Time) && Time->Day > 28))
) {
return FALSE;
}
return TRUE;
}
/**
Returns the current time and date information, and the time-keeping capabilities
of the hardware platform.
@param Time A pointer to storage to receive a snapshot of the current time.
@param Capabilities An optional pointer to a buffer to receive the real time clock
device's capabilities.
@retval EFI_SUCCESS The operation completed successfully.
@retval EFI_INVALID_PARAMETER Time is NULL.
@retval EFI_DEVICE_ERROR The time could not be retrieved due to hardware error.
@retval EFI_SECURITY_VIOLATION The time could not be retrieved due to an authentication failure.
**/
EFI_STATUS
EFIAPI
LibGetTime (
OUT EFI_TIME *Time,
OUT EFI_TIME_CAPABILITIES *Capabilities
)
{
EFI_STATUS Status = EFI_SUCCESS;
UINT32 EpochSeconds;
INT16 TimeZone;
UINT8 Daylight;
UINTN Size;
// Initialize the hardware if not already done
if (!mPL031Initialized) {
Status = InitializePL031 ();
if (EFI_ERROR (Status)) {
goto EXIT;
}
}
// Snapshot the time as early in the function call as possible
// On some platforms we may have access to a battery backed up hardware clock.
// If such RTC exists try to use it first.
Status = ArmPlatformSysConfigGet (SYS_CFG_RTC, &EpochSeconds);
if (Status == EFI_UNSUPPORTED) {
// Battery backed up hardware RTC does not exist, revert to PL031
EpochSeconds = MmioRead32 (PL031_RTC_DR_DATA_REGISTER);
Status = EFI_SUCCESS;
} else if (EFI_ERROR (Status)) {
// Battery backed up hardware RTC exists but could not be read due to error. Abort.
goto EXIT;
} else {
// Battery backed up hardware RTC exists and we read the time correctly from it.
// Now sync the PL031 to the new time.
MmioWrite32 (PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
}
// Ensure Time is a valid pointer
if (Time == NULL) {
Status = EFI_INVALID_PARAMETER;
goto EXIT;
}
// Get the current time zone information from non-volatile storage
Size = sizeof (TimeZone);
Status = gRT->GetVariable (
(CHAR16 *)mTimeZoneVariableName,
&gEfiCallerIdGuid,
NULL,
&Size,
(VOID *)&TimeZone
);
if (EFI_ERROR (Status)) {
ASSERT(Status != EFI_INVALID_PARAMETER);
ASSERT(Status != EFI_BUFFER_TOO_SMALL);
if (Status != EFI_NOT_FOUND)
goto EXIT;
// The time zone variable does not exist in non-volatile storage, so create it.
Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
// Store it
Status = gRT->SetVariable (
(CHAR16 *)mTimeZoneVariableName,
&gEfiCallerIdGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
Size,
(VOID *)&(Time->TimeZone)
);
if (EFI_ERROR (Status)) {
DEBUG ((
EFI_D_ERROR,
"LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
mTimeZoneVariableName,
Status
));
goto EXIT;
}
} else {
// Got the time zone
Time->TimeZone = TimeZone;
// Check TimeZone bounds: -1440 to 1440 or 2047
if (((Time->TimeZone < -1440) || (Time->TimeZone > 1440))
&& (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE)) {
Time->TimeZone = EFI_UNSPECIFIED_TIMEZONE;
}
// Adjust for the correct time zone
if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
EpochSeconds += Time->TimeZone * SEC_PER_MIN;
}
}
// Get the current daylight information from non-volatile storage
Size = sizeof (Daylight);
Status = gRT->GetVariable (
(CHAR16 *)mDaylightVariableName,
&gEfiCallerIdGuid,
NULL,
&Size,
(VOID *)&Daylight
);
if (EFI_ERROR (Status)) {
ASSERT(Status != EFI_INVALID_PARAMETER);
ASSERT(Status != EFI_BUFFER_TOO_SMALL);
if (Status != EFI_NOT_FOUND)
goto EXIT;
// The daylight variable does not exist in non-volatile storage, so create it.
Time->Daylight = 0;
// Store it
Status = gRT->SetVariable (
(CHAR16 *)mDaylightVariableName,
&gEfiCallerIdGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
Size,
(VOID *)&(Time->Daylight)
);
if (EFI_ERROR (Status)) {
DEBUG ((
EFI_D_ERROR,
"LibGetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
mDaylightVariableName,
Status
));
goto EXIT;
}
} else {
// Got the daylight information
Time->Daylight = Daylight;
// Adjust for the correct period
if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
// Convert to adjusted time, i.e. spring forwards one hour
EpochSeconds += SEC_PER_HOUR;
}
}
// Convert from internal 32-bit time to UEFI time
EpochToEfiTime (EpochSeconds, Time);
// Update the Capabilities info
if (Capabilities != NULL) {
// PL031 runs at frequency 1Hz
Capabilities->Resolution = PL031_COUNTS_PER_SECOND;
// Accuracy in ppm multiplied by 1,000,000, e.g. for 50ppm set 50,000,000
Capabilities->Accuracy = (UINT32)PcdGet32 (PcdPL031RtcPpmAccuracy);
// FALSE: Setting the time does not clear the values below the resolution level
Capabilities->SetsToZero = FALSE;
}
EXIT:
return Status;
}
/**
Sets the current local time and date information.
@param Time A pointer to the current time.
@retval EFI_SUCCESS The operation completed successfully.
@retval EFI_INVALID_PARAMETER A time field is out of range.
@retval EFI_DEVICE_ERROR The time could not be set due due to hardware error.
**/
EFI_STATUS
EFIAPI
LibSetTime (
IN EFI_TIME *Time
)
{
EFI_STATUS Status;
UINTN EpochSeconds;
// Check the input parameters are within the range specified by UEFI
if ((Time->Year < 1900) ||
(Time->Year > 9999) ||
(Time->Month < 1 ) ||
(Time->Month > 12 ) ||
(!DayValid (Time) ) ||
(Time->Hour > 23 ) ||
(Time->Minute > 59 ) ||
(Time->Second > 59 ) ||
(Time->Nanosecond > 999999999) ||
(!((Time->TimeZone == EFI_UNSPECIFIED_TIMEZONE) || ((Time->TimeZone >= -1440) && (Time->TimeZone <= 1440)))) ||
(Time->Daylight & (~(EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT)))
) {
Status = EFI_INVALID_PARAMETER;
goto EXIT;
}
// Because the PL031 is a 32-bit counter counting seconds,
// the maximum time span is just over 136 years.
// Time is stored in Unix Epoch format, so it starts in 1970,
// Therefore it can not exceed the year 2106.
if ((Time->Year < 1970) || (Time->Year >= 2106)) {
Status = EFI_UNSUPPORTED;
goto EXIT;
}
// Initialize the hardware if not already done
if (!mPL031Initialized) {
Status = InitializePL031 ();
if (EFI_ERROR (Status)) {
goto EXIT;
}
}
EpochSeconds = EfiTimeToEpoch (Time);
// Adjust for the correct time zone, i.e. convert to UTC time zone
if (Time->TimeZone != EFI_UNSPECIFIED_TIMEZONE) {
EpochSeconds -= Time->TimeZone * SEC_PER_MIN;
}
// TODO: Automatic Daylight activation
// Adjust for the correct period
if ((Time->Daylight & EFI_TIME_IN_DAYLIGHT) == EFI_TIME_IN_DAYLIGHT) {
// Convert to un-adjusted time, i.e. fall back one hour
EpochSeconds -= SEC_PER_HOUR;
}
// On some platforms we may have access to a battery backed up hardware clock.
//
// If such RTC exists then it must be updated first, before the PL031,
// to minimise any time drift. This is important because the battery backed-up
// RTC maintains the master time for the platform across reboots.
//
// If such RTC does not exist then the following function returns UNSUPPORTED.
Status = ArmPlatformSysConfigSet (SYS_CFG_RTC, EpochSeconds);
if ((EFI_ERROR (Status)) && (Status != EFI_UNSUPPORTED)){
// Any status message except SUCCESS and UNSUPPORTED indicates a hardware failure.
goto EXIT;
}
// Set the PL031
MmioWrite32 (PL031_RTC_LR_LOAD_REGISTER, EpochSeconds);
// The accesses to Variable Services can be very slow, because we may be writing to Flash.
// Do this after having set the RTC.
// Save the current time zone information into non-volatile storage
Status = gRT->SetVariable (
(CHAR16 *)mTimeZoneVariableName,
&gEfiCallerIdGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
sizeof (Time->TimeZone),
(VOID *)&(Time->TimeZone)
);
if (EFI_ERROR (Status)) {
DEBUG ((
EFI_D_ERROR,
"LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
mTimeZoneVariableName,
Status
));
goto EXIT;
}
// Save the current daylight information into non-volatile storage
Status = gRT->SetVariable (
(CHAR16 *)mDaylightVariableName,
&gEfiCallerIdGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
sizeof(Time->Daylight),
(VOID *)&(Time->Daylight)
);
if (EFI_ERROR (Status)) {
DEBUG ((
EFI_D_ERROR,
"LibSetTime: Failed to save %s variable to non-volatile storage, Status = %r\n",
mDaylightVariableName,
Status
));
goto EXIT;
}
EXIT:
return Status;
}
/**
Returns the current wakeup alarm clock setting.
@param Enabled Indicates if the alarm is currently enabled or disabled.
@param Pending Indicates if the alarm signal is pending and requires acknowledgement.
@param Time The current alarm setting.
@retval EFI_SUCCESS The alarm settings were returned.
@retval EFI_INVALID_PARAMETER Any parameter is NULL.
@retval EFI_DEVICE_ERROR The wakeup time could not be retrieved due to a hardware error.
**/
EFI_STATUS
EFIAPI
LibGetWakeupTime (
OUT BOOLEAN *Enabled,
OUT BOOLEAN *Pending,
OUT EFI_TIME *Time
)
{
// Not a required feature
return EFI_UNSUPPORTED;
}
/**
Sets the system wakeup alarm clock time.
@param Enabled Enable or disable the wakeup alarm.
@param Time If Enable is TRUE, the time to set the wakeup alarm for.
@retval EFI_SUCCESS If Enable is TRUE, then the wakeup alarm was enabled. If
Enable is FALSE, then the wakeup alarm was disabled.
@retval EFI_INVALID_PARAMETER A time field is out of range.
@retval EFI_DEVICE_ERROR The wakeup time could not be set due to a hardware error.
@retval EFI_UNSUPPORTED A wakeup timer is not supported on this platform.
**/
EFI_STATUS
EFIAPI
LibSetWakeupTime (
IN BOOLEAN Enabled,
OUT EFI_TIME *Time
)
{
// Not a required feature
return EFI_UNSUPPORTED;
}
/**
This is the declaration of an EFI image entry point. This can be the entry point to an application
written to this specification, an EFI boot service driver, or an EFI runtime driver.
@param ImageHandle Handle that identifies the loaded image.
@param SystemTable System Table for this image.
@retval EFI_SUCCESS The operation completed successfully.
**/
EFI_STATUS
EFIAPI
LibRtcInitialize (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
EFI_HANDLE Handle;
// Setup the setters and getters
gRT->GetTime = LibGetTime;
gRT->SetTime = LibSetTime;
gRT->GetWakeupTime = LibGetWakeupTime;
gRT->SetWakeupTime = LibSetWakeupTime;
// Install the protocol
Handle = NULL;
Status = gBS->InstallMultipleProtocolInterfaces (
&Handle,
&gEfiRealTimeClockArchProtocolGuid, NULL,
NULL
);
return Status;
}
/**
Fixup internal data so that EFI can be call in virtual mode.
Call the passed in Child Notify event and convert any pointers in
lib to virtual mode.
@param[in] Event The Event that is being processed
@param[in] Context Event Context
**/
VOID
EFIAPI
LibRtcVirtualNotifyEvent (
IN EFI_EVENT Event,
IN VOID *Context
)
{
//
// Only needed if you are going to support the OS calling RTC functions in virtual mode.
// You will need to call EfiConvertPointer (). To convert any stored physical addresses
// to virtual address. After the OS transitions to calling in virtual mode, all future
// runtime calls will be made in virtual mode.
//
return;
}