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- /** @file
- 16550 UART Serial Port library functions
- (C) Copyright 2014 Hewlett-Packard Development Company, L.P.<BR>
- Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
- SPDX-License-Identifier: BSD-2-Clause-Patent
- **/
- #include <Base.h>
- #include <IndustryStandard/Pci.h>
- #include <Library/SerialPortLib.h>
- #include <Library/PcdLib.h>
- #include <Library/IoLib.h>
- #include <Library/PciLib.h>
- #include <Library/PlatformHookLib.h>
- #include <Library/BaseLib.h>
- //
- // PCI Definitions.
- //
- #define PCI_BRIDGE_32_BIT_IO_SPACE 0x01
- //
- // 16550 UART register offsets and bitfields
- //
- #define R_UART_RXBUF 0
- #define R_UART_TXBUF 0
- #define R_UART_BAUD_LOW 0
- #define R_UART_BAUD_HIGH 1
- #define R_UART_FCR 2
- #define B_UART_FCR_FIFOE BIT0
- #define B_UART_FCR_FIFO64 BIT5
- #define R_UART_LCR 3
- #define B_UART_LCR_DLAB BIT7
- #define R_UART_MCR 4
- #define B_UART_MCR_DTRC BIT0
- #define B_UART_MCR_RTS BIT1
- #define R_UART_LSR 5
- #define B_UART_LSR_RXRDY BIT0
- #define B_UART_LSR_TXRDY BIT5
- #define B_UART_LSR_TEMT BIT6
- #define R_UART_MSR 6
- #define B_UART_MSR_CTS BIT4
- #define B_UART_MSR_DSR BIT5
- #define B_UART_MSR_RI BIT6
- #define B_UART_MSR_DCD BIT7
- //
- // 4-byte structure for each PCI node in PcdSerialPciDeviceInfo
- //
- typedef struct {
- UINT8 Device;
- UINT8 Function;
- UINT16 PowerManagementStatusAndControlRegister;
- } PCI_UART_DEVICE_INFO;
- /**
- Read an 8-bit 16550 register. If PcdSerialUseMmio is TRUE, then the value is read from
- MMIO space. If PcdSerialUseMmio is FALSE, then the value is read from I/O space. The
- parameter Offset is added to the base address of the 16550 registers that is specified
- by PcdSerialRegisterBase.
- @param Base The base address register of UART device.
- @param Offset The offset of the 16550 register to read.
- @return The value read from the 16550 register.
- **/
- UINT8
- SerialPortReadRegister (
- UINTN Base,
- UINTN Offset
- )
- {
- if (PcdGetBool (PcdSerialUseMmio)) {
- return MmioRead8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
- } else {
- return IoRead8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
- }
- }
- /**
- Write an 8-bit 16550 register. If PcdSerialUseMmio is TRUE, then the value is written to
- MMIO space. If PcdSerialUseMmio is FALSE, then the value is written to I/O space. The
- parameter Offset is added to the base address of the 16550 registers that is specified
- by PcdSerialRegisterBase.
- @param Base The base address register of UART device.
- @param Offset The offset of the 16550 register to write.
- @param Value The value to write to the 16550 register specified by Offset.
- @return The value written to the 16550 register.
- **/
- UINT8
- SerialPortWriteRegister (
- UINTN Base,
- UINTN Offset,
- UINT8 Value
- )
- {
- if (PcdGetBool (PcdSerialUseMmio)) {
- return MmioWrite8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), Value);
- } else {
- return IoWrite8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), Value);
- }
- }
- /**
- Update the value of an 16-bit PCI configuration register in a PCI device. If the
- PCI Configuration register specified by PciAddress is already programmed with a
- non-zero value, then return the current value. Otherwise update the PCI configuration
- register specified by PciAddress with the value specified by Value and return the
- value programmed into the PCI configuration register. All values must be masked
- using the bitmask specified by Mask.
- @param PciAddress PCI Library address of the PCI Configuration register to update.
- @param Value The value to program into the PCI Configuration Register.
- @param Mask Bitmask of the bits to check and update in the PCI configuration register.
- **/
- UINT16
- SerialPortLibUpdatePciRegister16 (
- UINTN PciAddress,
- UINT16 Value,
- UINT16 Mask
- )
- {
- UINT16 CurrentValue;
- CurrentValue = PciRead16 (PciAddress) & Mask;
- if (CurrentValue != 0) {
- return CurrentValue;
- }
- return PciWrite16 (PciAddress, Value & Mask);
- }
- /**
- Update the value of an 32-bit PCI configuration register in a PCI device. If the
- PCI Configuration register specified by PciAddress is already programmed with a
- non-zero value, then return the current value. Otherwise update the PCI configuration
- register specified by PciAddress with the value specified by Value and return the
- value programmed into the PCI configuration register. All values must be masked
- using the bitmask specified by Mask.
- @param PciAddress PCI Library address of the PCI Configuration register to update.
- @param Value The value to program into the PCI Configuration Register.
- @param Mask Bitmask of the bits to check and update in the PCI configuration register.
- @return The Secondary bus number that is actually programed into the PCI to PCI Bridge device.
- **/
- UINT32
- SerialPortLibUpdatePciRegister32 (
- UINTN PciAddress,
- UINT32 Value,
- UINT32 Mask
- )
- {
- UINT32 CurrentValue;
- CurrentValue = PciRead32 (PciAddress) & Mask;
- if (CurrentValue != 0) {
- return CurrentValue;
- }
- return PciWrite32 (PciAddress, Value & Mask);
- }
- /**
- Retrieve the I/O or MMIO base address register for the PCI UART device.
- This function assumes Root Bus Numer is Zero, and enables I/O and MMIO in PCI UART
- Device if they are not already enabled.
- @return The base address register of the UART device.
- **/
- UINTN
- GetSerialRegisterBase (
- VOID
- )
- {
- UINTN PciLibAddress;
- UINTN BusNumber;
- UINTN SubordinateBusNumber;
- UINT32 ParentIoBase;
- UINT32 ParentIoLimit;
- UINT16 ParentMemoryBase;
- UINT16 ParentMemoryLimit;
- UINT32 IoBase;
- UINT32 IoLimit;
- UINT16 MemoryBase;
- UINT16 MemoryLimit;
- UINTN SerialRegisterBase;
- UINTN BarIndex;
- UINT32 RegisterBaseMask;
- PCI_UART_DEVICE_INFO *DeviceInfo;
- //
- // Get PCI Device Info
- //
- DeviceInfo = (PCI_UART_DEVICE_INFO *) PcdGetPtr (PcdSerialPciDeviceInfo);
- //
- // If PCI Device Info is empty, then assume fixed address UART and return PcdSerialRegisterBase
- //
- if (DeviceInfo->Device == 0xff) {
- return (UINTN)PcdGet64 (PcdSerialRegisterBase);
- }
- //
- // Assume PCI Bus 0 I/O window is 0-64KB and MMIO windows is 0-4GB
- //
- ParentMemoryBase = 0 >> 16;
- ParentMemoryLimit = 0xfff00000 >> 16;
- ParentIoBase = 0 >> 12;
- ParentIoLimit = 0xf000 >> 12;
- //
- // Enable I/O and MMIO in PCI Bridge
- // Assume Root Bus Numer is Zero.
- //
- for (BusNumber = 0; (DeviceInfo + 1)->Device != 0xff; DeviceInfo++) {
- //
- // Compute PCI Lib Address to PCI to PCI Bridge
- //
- PciLibAddress = PCI_LIB_ADDRESS (BusNumber, DeviceInfo->Device, DeviceInfo->Function, 0);
- //
- // Retrieve and verify the bus numbers in the PCI to PCI Bridge
- //
- BusNumber = PciRead8 (PciLibAddress + PCI_BRIDGE_SECONDARY_BUS_REGISTER_OFFSET);
- SubordinateBusNumber = PciRead8 (PciLibAddress + PCI_BRIDGE_SUBORDINATE_BUS_REGISTER_OFFSET);
- if (BusNumber == 0 || BusNumber > SubordinateBusNumber) {
- return 0;
- }
- //
- // Retrieve and verify the I/O or MMIO decode window in the PCI to PCI Bridge
- //
- if (PcdGetBool (PcdSerialUseMmio)) {
- MemoryLimit = PciRead16 (PciLibAddress + OFFSET_OF (PCI_TYPE01, Bridge.MemoryLimit)) & 0xfff0;
- MemoryBase = PciRead16 (PciLibAddress + OFFSET_OF (PCI_TYPE01, Bridge.MemoryBase)) & 0xfff0;
- //
- // If PCI Bridge MMIO window is disabled, then return 0
- //
- if (MemoryLimit < MemoryBase) {
- return 0;
- }
- //
- // If PCI Bridge MMIO window is not in the address range decoded by the parent PCI Bridge, then return 0
- //
- if (MemoryBase < ParentMemoryBase || MemoryBase > ParentMemoryLimit || MemoryLimit > ParentMemoryLimit) {
- return 0;
- }
- ParentMemoryBase = MemoryBase;
- ParentMemoryLimit = MemoryLimit;
- } else {
- IoLimit = PciRead8 (PciLibAddress + OFFSET_OF (PCI_TYPE01, Bridge.IoLimit));
- if ((IoLimit & PCI_BRIDGE_32_BIT_IO_SPACE ) == 0) {
- IoLimit = IoLimit >> 4;
- } else {
- IoLimit = (PciRead16 (PciLibAddress + OFFSET_OF (PCI_TYPE01, Bridge.IoLimitUpper16)) << 4) | (IoLimit >> 4);
- }
- IoBase = PciRead8 (PciLibAddress + OFFSET_OF (PCI_TYPE01, Bridge.IoBase));
- if ((IoBase & PCI_BRIDGE_32_BIT_IO_SPACE ) == 0) {
- IoBase = IoBase >> 4;
- } else {
- IoBase = (PciRead16 (PciLibAddress + OFFSET_OF (PCI_TYPE01, Bridge.IoBaseUpper16)) << 4) | (IoBase >> 4);
- }
- //
- // If PCI Bridge I/O window is disabled, then return 0
- //
- if (IoLimit < IoBase) {
- return 0;
- }
- //
- // If PCI Bridge I/O window is not in the address range decoded by the parent PCI Bridge, then return 0
- //
- if (IoBase < ParentIoBase || IoBase > ParentIoLimit || IoLimit > ParentIoLimit) {
- return 0;
- }
- ParentIoBase = IoBase;
- ParentIoLimit = IoLimit;
- }
- }
- //
- // Compute PCI Lib Address to PCI UART
- //
- PciLibAddress = PCI_LIB_ADDRESS (BusNumber, DeviceInfo->Device, DeviceInfo->Function, 0);
- //
- // Find the first IO or MMIO BAR
- //
- RegisterBaseMask = 0xFFFFFFF0;
- for (BarIndex = 0; BarIndex < PCI_MAX_BAR; BarIndex ++) {
- SerialRegisterBase = PciRead32 (PciLibAddress + PCI_BASE_ADDRESSREG_OFFSET + BarIndex * 4);
- if (PcdGetBool (PcdSerialUseMmio) && ((SerialRegisterBase & BIT0) == 0)) {
- //
- // MMIO BAR is found
- //
- RegisterBaseMask = 0xFFFFFFF0;
- break;
- }
- if ((!PcdGetBool (PcdSerialUseMmio)) && ((SerialRegisterBase & BIT0) != 0)) {
- //
- // IO BAR is found
- //
- RegisterBaseMask = 0xFFFFFFF8;
- break;
- }
- }
- //
- // MMIO or IO BAR is not found.
- //
- if (BarIndex == PCI_MAX_BAR) {
- return 0;
- }
- //
- // Program UART BAR
- //
- SerialRegisterBase = SerialPortLibUpdatePciRegister32 (
- PciLibAddress + PCI_BASE_ADDRESSREG_OFFSET + BarIndex * 4,
- (UINT32)PcdGet64 (PcdSerialRegisterBase),
- RegisterBaseMask
- );
- //
- // Verify that the UART BAR is in the address range decoded by the parent PCI Bridge
- //
- if (PcdGetBool (PcdSerialUseMmio)) {
- if (((SerialRegisterBase >> 16) & 0xfff0) < ParentMemoryBase || ((SerialRegisterBase >> 16) & 0xfff0) > ParentMemoryLimit) {
- return 0;
- }
- } else {
- if ((SerialRegisterBase >> 12) < ParentIoBase || (SerialRegisterBase >> 12) > ParentIoLimit) {
- return 0;
- }
- }
- //
- // Enable I/O and MMIO in PCI UART Device if they are not already enabled
- //
- PciOr16 (
- PciLibAddress + PCI_COMMAND_OFFSET,
- PcdGetBool (PcdSerialUseMmio) ? EFI_PCI_COMMAND_MEMORY_SPACE : EFI_PCI_COMMAND_IO_SPACE
- );
- //
- // Force D0 state if a Power Management and Status Register is specified
- //
- if (DeviceInfo->PowerManagementStatusAndControlRegister != 0x00) {
- if ((PciRead16 (PciLibAddress + DeviceInfo->PowerManagementStatusAndControlRegister) & (BIT0 | BIT1)) != 0x00) {
- PciAnd16 (PciLibAddress + DeviceInfo->PowerManagementStatusAndControlRegister, (UINT16)~(BIT0 | BIT1));
- //
- // If PCI UART was not in D0, then make sure FIFOs are enabled, but do not reset FIFOs
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_FCR, (UINT8)(PcdGet8 (PcdSerialFifoControl) & (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64)));
- }
- }
- //
- // Get PCI Device Info
- //
- DeviceInfo = (PCI_UART_DEVICE_INFO *) PcdGetPtr (PcdSerialPciDeviceInfo);
- //
- // Enable I/O or MMIO in PCI Bridge
- // Assume Root Bus Numer is Zero.
- //
- for (BusNumber = 0; (DeviceInfo + 1)->Device != 0xff; DeviceInfo++) {
- //
- // Compute PCI Lib Address to PCI to PCI Bridge
- //
- PciLibAddress = PCI_LIB_ADDRESS (BusNumber, DeviceInfo->Device, DeviceInfo->Function, 0);
- //
- // Enable the I/O or MMIO decode windows in the PCI to PCI Bridge
- //
- PciOr16 (
- PciLibAddress + PCI_COMMAND_OFFSET,
- PcdGetBool (PcdSerialUseMmio) ? EFI_PCI_COMMAND_MEMORY_SPACE : EFI_PCI_COMMAND_IO_SPACE
- );
- //
- // Force D0 state if a Power Management and Status Register is specified
- //
- if (DeviceInfo->PowerManagementStatusAndControlRegister != 0x00) {
- if ((PciRead16 (PciLibAddress + DeviceInfo->PowerManagementStatusAndControlRegister) & (BIT0 | BIT1)) != 0x00) {
- PciAnd16 (PciLibAddress + DeviceInfo->PowerManagementStatusAndControlRegister, (UINT16)~(BIT0 | BIT1));
- }
- }
- BusNumber = PciRead8 (PciLibAddress + PCI_BRIDGE_SECONDARY_BUS_REGISTER_OFFSET);
- }
- return SerialRegisterBase;
- }
- /**
- Return whether the hardware flow control signal allows writing.
- @param SerialRegisterBase The base address register of UART device.
- @retval TRUE The serial port is writable.
- @retval FALSE The serial port is not writable.
- **/
- BOOLEAN
- SerialPortWritable (
- UINTN SerialRegisterBase
- )
- {
- if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
- if (PcdGetBool (PcdSerialDetectCable)) {
- //
- // Wait for both DSR and CTS to be set
- // DSR is set if a cable is connected.
- // CTS is set if it is ok to transmit data
- //
- // DSR CTS Description Action
- // === === ======================================== ========
- // 0 0 No cable connected. Wait
- // 0 1 No cable connected. Wait
- // 1 0 Cable connected, but not clear to send. Wait
- // 1 1 Cable connected, and clear to send. Transmit
- //
- return (BOOLEAN) ((SerialPortReadRegister (SerialRegisterBase, R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) == (B_UART_MSR_DSR | B_UART_MSR_CTS));
- } else {
- //
- // Wait for both DSR and CTS to be set OR for DSR to be clear.
- // DSR is set if a cable is connected.
- // CTS is set if it is ok to transmit data
- //
- // DSR CTS Description Action
- // === === ======================================== ========
- // 0 0 No cable connected. Transmit
- // 0 1 No cable connected. Transmit
- // 1 0 Cable connected, but not clear to send. Wait
- // 1 1 Cable connected, and clear to send. Transmit
- //
- return (BOOLEAN) ((SerialPortReadRegister (SerialRegisterBase, R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) != (B_UART_MSR_DSR));
- }
- }
- return TRUE;
- }
- /**
- Initialize the serial device hardware.
- If no initialization is required, then return RETURN_SUCCESS.
- If the serial device was successfully initialized, then return RETURN_SUCCESS.
- If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.
- @retval RETURN_SUCCESS The serial device was initialized.
- @retval RETURN_DEVICE_ERROR The serial device could not be initialized.
- **/
- RETURN_STATUS
- EFIAPI
- SerialPortInitialize (
- VOID
- )
- {
- RETURN_STATUS Status;
- UINTN SerialRegisterBase;
- UINT32 Divisor;
- UINT32 CurrentDivisor;
- BOOLEAN Initialized;
- //
- // Perform platform specific initialization required to enable use of the 16550 device
- // at the location specified by PcdSerialUseMmio and PcdSerialRegisterBase.
- //
- Status = PlatformHookSerialPortInitialize ();
- if (RETURN_ERROR (Status)) {
- return Status;
- }
- //
- // Calculate divisor for baud generator
- // Ref_Clk_Rate / Baud_Rate / 16
- //
- Divisor = PcdGet32 (PcdSerialClockRate) / (PcdGet32 (PcdSerialBaudRate) * 16);
- if ((PcdGet32 (PcdSerialClockRate) % (PcdGet32 (PcdSerialBaudRate) * 16)) >= PcdGet32 (PcdSerialBaudRate) * 8) {
- Divisor++;
- }
- //
- // Get the base address of the serial port in either I/O or MMIO space
- //
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return RETURN_DEVICE_ERROR;
- }
- //
- // See if the serial port is already initialized
- //
- Initialized = TRUE;
- if ((SerialPortReadRegister (SerialRegisterBase, R_UART_LCR) & 0x3F) != (PcdGet8 (PcdSerialLineControl) & 0x3F)) {
- Initialized = FALSE;
- }
- SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, (UINT8)(SerialPortReadRegister (SerialRegisterBase, R_UART_LCR) | B_UART_LCR_DLAB));
- CurrentDivisor = SerialPortReadRegister (SerialRegisterBase, R_UART_BAUD_HIGH) << 8;
- CurrentDivisor |= (UINT32) SerialPortReadRegister (SerialRegisterBase, R_UART_BAUD_LOW);
- SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, (UINT8)(SerialPortReadRegister (SerialRegisterBase, R_UART_LCR) & ~B_UART_LCR_DLAB));
- if (CurrentDivisor != Divisor) {
- Initialized = FALSE;
- }
- if (Initialized) {
- return RETURN_SUCCESS;
- }
- //
- // Wait for the serial port to be ready.
- // Verify that both the transmit FIFO and the shift register are empty.
- //
- while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) != (B_UART_LSR_TEMT | B_UART_LSR_TXRDY));
- //
- // Configure baud rate
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, B_UART_LCR_DLAB);
- SerialPortWriteRegister (SerialRegisterBase, R_UART_BAUD_HIGH, (UINT8) (Divisor >> 8));
- SerialPortWriteRegister (SerialRegisterBase, R_UART_BAUD_LOW, (UINT8) (Divisor & 0xff));
- //
- // Clear DLAB and configure Data Bits, Parity, and Stop Bits.
- // Strip reserved bits from PcdSerialLineControl
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, (UINT8)(PcdGet8 (PcdSerialLineControl) & 0x3F));
- //
- // Enable and reset FIFOs
- // Strip reserved bits from PcdSerialFifoControl
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_FCR, 0x00);
- SerialPortWriteRegister (SerialRegisterBase, R_UART_FCR, (UINT8)(PcdGet8 (PcdSerialFifoControl) & (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64)));
- //
- // Set RTS and DTR in Modem Control Register(MCR)
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR,
- EFI_SERIAL_REQUEST_TO_SEND | EFI_SERIAL_DATA_TERMINAL_READY);
- return RETURN_SUCCESS;
- }
- /**
- Write data from buffer to serial device.
- Writes NumberOfBytes data bytes from Buffer to the serial device.
- The number of bytes actually written to the serial device is returned.
- If the return value is less than NumberOfBytes, then the write operation failed.
- If Buffer is NULL, then ASSERT().
- If NumberOfBytes is zero, then return 0.
- @param Buffer Pointer to the data buffer to be written.
- @param NumberOfBytes Number of bytes to written to the serial device.
- @retval 0 NumberOfBytes is 0.
- @retval >0 The number of bytes written to the serial device.
- If this value is less than NumberOfBytes, then the write operation failed.
- **/
- UINTN
- EFIAPI
- SerialPortWrite (
- IN UINT8 *Buffer,
- IN UINTN NumberOfBytes
- )
- {
- UINTN SerialRegisterBase;
- UINTN Result;
- UINTN Index;
- UINTN FifoSize;
- if (Buffer == NULL) {
- return 0;
- }
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return 0;
- }
- if (NumberOfBytes == 0) {
- //
- // Flush the hardware
- //
- //
- // Wait for both the transmit FIFO and shift register empty.
- //
- while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) != (B_UART_LSR_TEMT | B_UART_LSR_TXRDY));
- //
- // Wait for the hardware flow control signal
- //
- while (!SerialPortWritable (SerialRegisterBase));
- return 0;
- }
- //
- // Compute the maximum size of the Tx FIFO
- //
- FifoSize = 1;
- if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFOE) != 0) {
- if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFO64) == 0) {
- FifoSize = 16;
- } else {
- FifoSize = PcdGet32 (PcdSerialExtendedTxFifoSize);
- }
- }
- Result = NumberOfBytes;
- while (NumberOfBytes != 0) {
- //
- // Wait for the serial port to be ready, to make sure both the transmit FIFO
- // and shift register empty.
- //
- while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & B_UART_LSR_TEMT) == 0);
- //
- // Fill then entire Tx FIFO
- //
- for (Index = 0; Index < FifoSize && NumberOfBytes != 0; Index++, NumberOfBytes--, Buffer++) {
- //
- // Wait for the hardware flow control signal
- //
- while (!SerialPortWritable (SerialRegisterBase));
- //
- // Write byte to the transmit buffer.
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_TXBUF, *Buffer);
- }
- }
- return Result;
- }
- /**
- Reads data from a serial device into a buffer.
- @param Buffer Pointer to the data buffer to store the data read from the serial device.
- @param NumberOfBytes Number of bytes to read from the serial device.
- @retval 0 NumberOfBytes is 0.
- @retval >0 The number of bytes read from the serial device.
- If this value is less than NumberOfBytes, then the read operation failed.
- **/
- UINTN
- EFIAPI
- SerialPortRead (
- OUT UINT8 *Buffer,
- IN UINTN NumberOfBytes
- )
- {
- UINTN SerialRegisterBase;
- UINTN Result;
- UINT8 Mcr;
- if (NULL == Buffer) {
- return 0;
- }
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return 0;
- }
- Mcr = (UINT8)(SerialPortReadRegister (SerialRegisterBase, R_UART_MCR) & ~B_UART_MCR_RTS);
- for (Result = 0; NumberOfBytes-- != 0; Result++, Buffer++) {
- //
- // Wait for the serial port to have some data.
- //
- while ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & B_UART_LSR_RXRDY) == 0) {
- if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
- //
- // Set RTS to let the peer send some data
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, (UINT8)(Mcr | B_UART_MCR_RTS));
- }
- }
- if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
- //
- // Clear RTS to prevent peer from sending data
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, Mcr);
- }
- //
- // Read byte from the receive buffer.
- //
- *Buffer = SerialPortReadRegister (SerialRegisterBase, R_UART_RXBUF);
- }
- return Result;
- }
- /**
- Polls a serial device to see if there is any data waiting to be read.
- Polls a serial device to see if there is any data waiting to be read.
- If there is data waiting to be read from the serial device, then TRUE is returned.
- If there is no data waiting to be read from the serial device, then FALSE is returned.
- @retval TRUE Data is waiting to be read from the serial device.
- @retval FALSE There is no data waiting to be read from the serial device.
- **/
- BOOLEAN
- EFIAPI
- SerialPortPoll (
- VOID
- )
- {
- UINTN SerialRegisterBase;
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return FALSE;
- }
- //
- // Read the serial port status
- //
- if ((SerialPortReadRegister (SerialRegisterBase, R_UART_LSR) & B_UART_LSR_RXRDY) != 0) {
- if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
- //
- // Clear RTS to prevent peer from sending data
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, (UINT8)(SerialPortReadRegister (SerialRegisterBase, R_UART_MCR) & ~B_UART_MCR_RTS));
- }
- return TRUE;
- }
- if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
- //
- // Set RTS to let the peer send some data
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, (UINT8)(SerialPortReadRegister (SerialRegisterBase, R_UART_MCR) | B_UART_MCR_RTS));
- }
- return FALSE;
- }
- /**
- Sets the control bits on a serial device.
- @param Control Sets the bits of Control that are settable.
- @retval RETURN_SUCCESS The new control bits were set on the serial device.
- @retval RETURN_UNSUPPORTED The serial device does not support this operation.
- @retval RETURN_DEVICE_ERROR The serial device is not functioning correctly.
- **/
- RETURN_STATUS
- EFIAPI
- SerialPortSetControl (
- IN UINT32 Control
- )
- {
- UINTN SerialRegisterBase;
- UINT8 Mcr;
- //
- // First determine the parameter is invalid.
- //
- if ((Control & (~(EFI_SERIAL_REQUEST_TO_SEND | EFI_SERIAL_DATA_TERMINAL_READY |
- EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE))) != 0) {
- return RETURN_UNSUPPORTED;
- }
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return RETURN_UNSUPPORTED;
- }
- //
- // Read the Modem Control Register.
- //
- Mcr = SerialPortReadRegister (SerialRegisterBase, R_UART_MCR);
- Mcr &= (~(B_UART_MCR_DTRC | B_UART_MCR_RTS));
- if ((Control & EFI_SERIAL_DATA_TERMINAL_READY) == EFI_SERIAL_DATA_TERMINAL_READY) {
- Mcr |= B_UART_MCR_DTRC;
- }
- if ((Control & EFI_SERIAL_REQUEST_TO_SEND) == EFI_SERIAL_REQUEST_TO_SEND) {
- Mcr |= B_UART_MCR_RTS;
- }
- //
- // Write the Modem Control Register.
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, Mcr);
- return RETURN_SUCCESS;
- }
- /**
- Retrieve the status of the control bits on a serial device.
- @param Control A pointer to return the current control signals from the serial device.
- @retval RETURN_SUCCESS The control bits were read from the serial device.
- @retval RETURN_UNSUPPORTED The serial device does not support this operation.
- @retval RETURN_DEVICE_ERROR The serial device is not functioning correctly.
- **/
- RETURN_STATUS
- EFIAPI
- SerialPortGetControl (
- OUT UINT32 *Control
- )
- {
- UINTN SerialRegisterBase;
- UINT8 Msr;
- UINT8 Mcr;
- UINT8 Lsr;
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return RETURN_UNSUPPORTED;
- }
- *Control = 0;
- //
- // Read the Modem Status Register.
- //
- Msr = SerialPortReadRegister (SerialRegisterBase, R_UART_MSR);
- if ((Msr & B_UART_MSR_CTS) == B_UART_MSR_CTS) {
- *Control |= EFI_SERIAL_CLEAR_TO_SEND;
- }
- if ((Msr & B_UART_MSR_DSR) == B_UART_MSR_DSR) {
- *Control |= EFI_SERIAL_DATA_SET_READY;
- }
- if ((Msr & B_UART_MSR_RI) == B_UART_MSR_RI) {
- *Control |= EFI_SERIAL_RING_INDICATE;
- }
- if ((Msr & B_UART_MSR_DCD) == B_UART_MSR_DCD) {
- *Control |= EFI_SERIAL_CARRIER_DETECT;
- }
- //
- // Read the Modem Control Register.
- //
- Mcr = SerialPortReadRegister (SerialRegisterBase, R_UART_MCR);
- if ((Mcr & B_UART_MCR_DTRC) == B_UART_MCR_DTRC) {
- *Control |= EFI_SERIAL_DATA_TERMINAL_READY;
- }
- if ((Mcr & B_UART_MCR_RTS) == B_UART_MCR_RTS) {
- *Control |= EFI_SERIAL_REQUEST_TO_SEND;
- }
- if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {
- *Control |= EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE;
- }
- //
- // Read the Line Status Register.
- //
- Lsr = SerialPortReadRegister (SerialRegisterBase, R_UART_LSR);
- if ((Lsr & (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) == (B_UART_LSR_TEMT | B_UART_LSR_TXRDY)) {
- *Control |= EFI_SERIAL_OUTPUT_BUFFER_EMPTY;
- }
- if ((Lsr & B_UART_LSR_RXRDY) == 0) {
- *Control |= EFI_SERIAL_INPUT_BUFFER_EMPTY;
- }
- return RETURN_SUCCESS;
- }
- /**
- Sets the baud rate, receive FIFO depth, transmit/receive time out, parity,
- data bits, and stop bits on a serial device.
- @param BaudRate The requested baud rate. A BaudRate value of 0 will use the
- device's default interface speed.
- On output, the value actually set.
- @param ReceiveFifoDepth The requested depth of the FIFO on the receive side of the
- serial interface. A ReceiveFifoDepth value of 0 will use
- the device's default FIFO depth.
- On output, the value actually set.
- @param Timeout The requested time out for a single character in microseconds.
- This timeout applies to both the transmit and receive side of the
- interface. A Timeout value of 0 will use the device's default time
- out value.
- On output, the value actually set.
- @param Parity The type of parity to use on this serial device. A Parity value of
- DefaultParity will use the device's default parity value.
- On output, the value actually set.
- @param DataBits The number of data bits to use on the serial device. A DataBits
- value of 0 will use the device's default data bit setting.
- On output, the value actually set.
- @param StopBits The number of stop bits to use on this serial device. A StopBits
- value of DefaultStopBits will use the device's default number of
- stop bits.
- On output, the value actually set.
- @retval RETURN_SUCCESS The new attributes were set on the serial device.
- @retval RETURN_UNSUPPORTED The serial device does not support this operation.
- @retval RETURN_INVALID_PARAMETER One or more of the attributes has an unsupported value.
- @retval RETURN_DEVICE_ERROR The serial device is not functioning correctly.
- **/
- RETURN_STATUS
- EFIAPI
- SerialPortSetAttributes (
- IN OUT UINT64 *BaudRate,
- IN OUT UINT32 *ReceiveFifoDepth,
- IN OUT UINT32 *Timeout,
- IN OUT EFI_PARITY_TYPE *Parity,
- IN OUT UINT8 *DataBits,
- IN OUT EFI_STOP_BITS_TYPE *StopBits
- )
- {
- UINTN SerialRegisterBase;
- UINT32 SerialBaudRate;
- UINTN Divisor;
- UINT8 Lcr;
- UINT8 LcrData;
- UINT8 LcrParity;
- UINT8 LcrStop;
- SerialRegisterBase = GetSerialRegisterBase ();
- if (SerialRegisterBase ==0) {
- return RETURN_UNSUPPORTED;
- }
- //
- // Check for default settings and fill in actual values.
- //
- if (*BaudRate == 0) {
- *BaudRate = PcdGet32 (PcdSerialBaudRate);
- }
- SerialBaudRate = (UINT32) *BaudRate;
- if (*DataBits == 0) {
- LcrData = (UINT8) (PcdGet8 (PcdSerialLineControl) & 0x3);
- *DataBits = LcrData + 5;
- } else {
- if ((*DataBits < 5) || (*DataBits > 8)) {
- return RETURN_INVALID_PARAMETER;
- }
- //
- // Map 5..8 to 0..3
- //
- LcrData = (UINT8) (*DataBits - (UINT8) 5);
- }
- if (*Parity == DefaultParity) {
- LcrParity = (UINT8) ((PcdGet8 (PcdSerialLineControl) >> 3) & 0x7);
- switch (LcrParity) {
- case 0:
- *Parity = NoParity;
- break;
- case 3:
- *Parity = EvenParity;
- break;
- case 1:
- *Parity = OddParity;
- break;
- case 7:
- *Parity = SpaceParity;
- break;
- case 5:
- *Parity = MarkParity;
- break;
- default:
- break;
- }
- } else {
- switch (*Parity) {
- case NoParity:
- LcrParity = 0;
- break;
- case EvenParity:
- LcrParity = 3;
- break;
- case OddParity:
- LcrParity = 1;
- break;
- case SpaceParity:
- LcrParity = 7;
- break;
- case MarkParity:
- LcrParity = 5;
- break;
- default:
- return RETURN_INVALID_PARAMETER;
- }
- }
- if (*StopBits == DefaultStopBits) {
- LcrStop = (UINT8) ((PcdGet8 (PcdSerialLineControl) >> 2) & 0x1);
- switch (LcrStop) {
- case 0:
- *StopBits = OneStopBit;
- break;
- case 1:
- if (*DataBits == 5) {
- *StopBits = OneFiveStopBits;
- } else {
- *StopBits = TwoStopBits;
- }
- break;
- default:
- break;
- }
- } else {
- switch (*StopBits) {
- case OneStopBit:
- LcrStop = 0;
- break;
- case OneFiveStopBits:
- case TwoStopBits:
- LcrStop = 1;
- break;
- default:
- return RETURN_INVALID_PARAMETER;
- }
- }
- //
- // Calculate divisor for baud generator
- // Ref_Clk_Rate / Baud_Rate / 16
- //
- Divisor = PcdGet32 (PcdSerialClockRate) / (SerialBaudRate * 16);
- if ((PcdGet32 (PcdSerialClockRate) % (SerialBaudRate * 16)) >= SerialBaudRate * 8) {
- Divisor++;
- }
- //
- // Configure baud rate
- //
- SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, B_UART_LCR_DLAB);
- SerialPortWriteRegister (SerialRegisterBase, R_UART_BAUD_HIGH, (UINT8) (Divisor >> 8));
- SerialPortWriteRegister (SerialRegisterBase, R_UART_BAUD_LOW, (UINT8) (Divisor & 0xff));
- //
- // Clear DLAB and configure Data Bits, Parity, and Stop Bits.
- // Strip reserved bits from line control value
- //
- Lcr = (UINT8) ((LcrParity << 3) | (LcrStop << 2) | LcrData);
- SerialPortWriteRegister (SerialRegisterBase, R_UART_LCR, (UINT8) (Lcr & 0x3F));
- return RETURN_SUCCESS;
- }
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