diff options
Diffstat (limited to 'Omap35xxPkg/SmbusDxe/Smbus.c')
| -rw-r--r-- | Omap35xxPkg/SmbusDxe/Smbus.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/Omap35xxPkg/SmbusDxe/Smbus.c b/Omap35xxPkg/SmbusDxe/Smbus.c new file mode 100644 index 0000000000..35b17eb1fb --- /dev/null +++ b/Omap35xxPkg/SmbusDxe/Smbus.c @@ -0,0 +1,325 @@ +/** @file + + Copyright (c) 2008-2009, Apple Inc. All rights reserved. + + All rights reserved. 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 <Omap3530/Omap3530.h> + +#include <Library/DebugLib.h> +#include <Library/IoLib.h> +#include <Library/UefiBootServicesTableLib.h> + +#include <Protocol/SmbusHc.h> + +#define MAX_RETRY 1000 + +// +// Internal Functions +// +STATIC +EFI_STATUS +WaitForBusBusy ( + VOID + ) +{ + UINTN Retry = 0; + + while (++Retry < MAX_RETRY && (MmioRead16(I2C_STAT) & BB) == 0x1); + + if (Retry == MAX_RETRY) { + return EFI_TIMEOUT; + } + + return EFI_SUCCESS; +} + +STATIC +EFI_STATUS +PollForStatus( + UINT16 StatusBit + ) +{ + UINTN Retry = 0; + + while(Retry < MAX_RETRY) { + if (MmioRead16(I2C_STAT) & StatusBit) { + //Clear particular status bit from Status register. + MmioOr16(I2C_STAT, StatusBit); + break; + } + Retry++; + } + + if (Retry == MAX_RETRY) { + return EFI_TIMEOUT; + } + + return EFI_SUCCESS; +} + +STATIC +EFI_STATUS +ConfigureI2c ( + VOID + ) +{ + //Program prescaler to obtain 12-MHz clock + MmioWrite16(I2C_PSC, 0x0000); + + //Program SCLL and SCLH + //NOTE: Following values are the register dump after U-Boot code executed. + //We need to figure out how its calculated based on the I2C functional clock and I2C_PSC. + MmioWrite16(I2C_SCLL, 0x0035); + MmioWrite16(I2C_SCLH, 0x0035); + + //Take the I2C controller out of reset. + MmioOr16(I2C_CON, I2C_EN); + + //Initialize the I2C controller. + + //Set I2C controller in Master mode. + MmioOr16(I2C_CON, MST); + + //Enable interrupts for receive/transmit mode. + MmioOr16(I2C_IE, (XRDY_IE | RRDY_IE | ARDY_IE | NACK_IE)); + + return EFI_SUCCESS; +} + +STATIC +EFI_STATUS +I2CReadOneByte ( + UINT8 *Data + ) +{ + EFI_STATUS Status; + + //I2C bus status checking + Status = WaitForBusBusy(); + if (EFI_ERROR(Status)) { + return Status; + } + + //Poll till Receive ready bit is set. + Status = PollForStatus(RRDY); + if (EFI_ERROR(Status)) { + return Status; + } + + *Data = MmioRead8(I2C_DATA); + + return EFI_SUCCESS; +} + +STATIC +EFI_STATUS +I2CWriteOneByte ( + UINT8 Data + ) +{ + EFI_STATUS Status; + + //I2C bus status checking + Status = WaitForBusBusy(); + if (EFI_ERROR(Status)) { + return Status; + } + + //Data transfer + //Poll till Transmit ready bit is set + Status = PollForStatus(XRDY); + if (EFI_ERROR(Status)) { + return Status; + } + + MmioWrite8(I2C_DATA, Data); + + //Wait and check if the NACK is not set. + gBS->Stall(1000); + if (MmioRead16(I2C_STAT) & NACK) { + return EFI_DEVICE_ERROR; + } + + return EFI_SUCCESS; +} + +STATIC +EFI_STATUS +SmbusBlockRead ( + OUT UINT8 *Buffer, + IN UINTN Length + ) +{ + UINTN Index = 0; + EFI_STATUS Status = EFI_SUCCESS; + + //Transfer configuration for receiving data. + MmioWrite16(I2C_CNT, Length); + //Need stop bit before sending data. + MmioWrite16(I2C_CON, (I2C_EN | MST | STP | STT)); + + while (Index < Length) { + //Read a byte + Status = I2CReadOneByte(&Buffer[Index++]); + if (EFI_ERROR(Status)) { + return Status; + } + } + + //Transfer completion + Status = PollForStatus(ARDY); + if (EFI_ERROR(Status)) { + return Status; + } + + return Status; +} + +STATIC +EFI_STATUS +SmbusBlockWrite ( + IN UINT8 *Buffer, + IN UINTN Length + ) +{ + UINTN Index = 0; + EFI_STATUS Status = EFI_SUCCESS; + + //Transfer configuration for transmitting data + MmioWrite16(I2C_CNT, Length); + MmioWrite16(I2C_CON, (I2C_EN | TRX | MST | STT | STP)); + + while (Index < Length) { + //Send a byte + Status = I2CWriteOneByte(Buffer[Index++]); + if (EFI_ERROR(Status)) { + return Status; + } + } + + //Transfer completion + Status = PollForStatus(ARDY); + if (EFI_ERROR(Status)) { + return Status; + } + + return Status; +} + +// +// Public Functions. +// +EFI_STATUS +EFIAPI +SmbusExecute ( + IN CONST EFI_SMBUS_HC_PROTOCOL *This, + IN CONST EFI_SMBUS_DEVICE_ADDRESS SlaveAddress, + IN CONST EFI_SMBUS_DEVICE_COMMAND Command, + IN CONST EFI_SMBUS_OPERATION Operation, + IN CONST BOOLEAN PecCheck, + IN OUT UINTN *Length, + IN OUT VOID *Buffer + ) +{ + UINT8 *ByteBuffer = Buffer; + EFI_STATUS Status = EFI_SUCCESS; + UINT8 SlaveAddr = (UINT8)(SlaveAddress.SmbusDeviceAddress); + + if (PecCheck) { + return EFI_UNSUPPORTED; + } + + if ((Operation != EfiSmbusWriteBlock) && (Operation != EfiSmbusReadBlock)) { + return EFI_UNSUPPORTED; + } + + //Set the Slave address. + MmioWrite16(I2C_SA, SlaveAddr); + + if (Operation == EfiSmbusReadBlock) { + Status = SmbusBlockRead(ByteBuffer, *Length); + } else if (Operation == EfiSmbusWriteBlock) { + Status = SmbusBlockWrite(ByteBuffer, *Length); + } + + return Status; +} + +EFI_STATUS +EFIAPI +SmbusArpDevice ( + IN CONST EFI_SMBUS_HC_PROTOCOL *This, + IN CONST BOOLEAN ArpAll, + IN CONST EFI_SMBUS_UDID *SmbusUdid OPTIONAL, + IN OUT EFI_SMBUS_DEVICE_ADDRESS *SlaveAddress OPTIONAL + ) +{ + return EFI_UNSUPPORTED; +} + + +EFI_STATUS +EFIAPI +SmbusGetArpMap ( + IN CONST EFI_SMBUS_HC_PROTOCOL *This, + IN OUT UINTN *Length, + IN OUT EFI_SMBUS_DEVICE_MAP **SmbusDeviceMap + ) +{ + return EFI_UNSUPPORTED; +} + + +EFI_STATUS +EFIAPI +SmbusNotify ( + IN CONST EFI_SMBUS_HC_PROTOCOL *This, + IN CONST EFI_SMBUS_DEVICE_ADDRESS SlaveAddress, + IN CONST UINTN Data, + IN CONST EFI_SMBUS_NOTIFY_FUNCTION NotifyFunction + ) +{ + return EFI_UNSUPPORTED; +} + +EFI_SMBUS_HC_PROTOCOL SmbusProtocol = +{ + SmbusExecute, + SmbusArpDevice, + SmbusGetArpMap, + SmbusNotify +}; + +EFI_STATUS +InitializeSmbus ( + IN EFI_HANDLE ImageHandle, + IN EFI_SYSTEM_TABLE *SystemTable + ) +{ + EFI_HANDLE Handle = NULL; + EFI_STATUS Status; + + //Configure I2C controller. + Status = ConfigureI2c(); + if (EFI_ERROR(Status)) { + DEBUG ((EFI_D_ERROR, "InitializeI2c fails.\n")); + return Status; + } + + // Install the SMBUS interface + Status = gBS->InstallMultipleProtocolInterfaces(&Handle, &gEfiSmbusHcProtocolGuid, &SmbusProtocol, NULL); + ASSERT_EFI_ERROR(Status); + + return Status; +} + |