/** @file
  16550 and PL011 Serial Port library functions for Raspberry Pi

  Copyright (c) 2020, Pete Batard <pete@akeo.ie>
  Copyright (c) 2018, AMD Incorporated. All rights reserved.<BR>
  Copyright (c) 2014, Hewlett-Packard Development Company, L.P.<BR>
  Copyright (c) 2012 - 2016, ARM Ltd. All rights reserved.<BR>
  Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
  Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>

  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <Base.h>
#include <Library/IoLib.h>
#include <Library/PcdLib.h>
#include <Library/PL011UartClockLib.h>
#include <Library/PL011UartLib.h>
#include <Library/SerialPortLib.h>

#include "DualSerialPortLib.h"

/**
  Return the baud generator divisor to use for 16650 setup.

  @param  SerialBaudRate The desired baud rate.

  @return The baud generator divisor.
**/
STATIC
UINT32
SerialPortGetDivisor (
  UINT32  SerialBaudRate
)
{
  UINT32              BaseClockRate;
  UINT32              Divisor;

  BaseClockRate = PcdGet32 (PcdSerialClockRate);

  //
  // As per the BCM2xxx datasheets:
  // baudrate = system_clock_freq / (8 * (divisor + 1)).
  //
  Divisor = BaseClockRate / (SerialBaudRate * 8);
  if (Divisor != 0) {
    Divisor--;
  }
  return Divisor;
}

/**
  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
  )
{
  UINTN               SerialRegisterBase;
  UINT32              Divisor;
  UINT32              CurrentDivisor;
  BOOLEAN             Initialized;
  UINT64              BaudRate;
  UINT32              ReceiveFifoDepth;
  EFI_PARITY_TYPE     Parity;
  UINT8               DataBits;
  EFI_STOP_BITS_TYPE  StopBits;

  //
  // First thing we need to do is determine which of PL011 or miniUART is selected
  //
  if (!UsePl011UartSet) {
    UsePl011Uart = ((MmioRead32(GPIO_BASE_ADDRESS + 4) & 0x0003F000) == 0x00024000);
    UsePl011UartSet = TRUE;
  }

  if (UsePl011Uart) {
    BaudRate = FixedPcdGet64 (PcdUartDefaultBaudRate);
    ReceiveFifoDepth = 0;         // Use default FIFO depth
    Parity = (EFI_PARITY_TYPE)FixedPcdGet8 (PcdUartDefaultParity);
    DataBits = FixedPcdGet8 (PcdUartDefaultDataBits);
    StopBits = (EFI_STOP_BITS_TYPE) FixedPcdGet8 (PcdUartDefaultStopBits);

    return PL011UartInitializePort (
             PL011_UART_REGISTER_BASE,
             PL011UartClockGetFreq(),
             &BaudRate,
             &ReceiveFifoDepth,
             &Parity,
             &DataBits,
             &StopBits
             );
  } else {
    SerialRegisterBase = MINI_UART_REGISTER_BASE;
    Divisor = SerialPortGetDivisor (PcdGet32 (PcdSerialBaudRate));

    //
    // 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 FIFO Polled Mode by clearing IER after setting FCR
    //
    SerialPortWriteRegister (SerialRegisterBase, R_UART_IER, 0x00);

    //
    // Put Modem Control Register(MCR) into its reset state of 0x00.
    //
    SerialPortWriteRegister (SerialRegisterBase, R_UART_MCR, 0x00);

    return RETURN_SUCCESS;
  }
}

/**
  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 (UsePl011Uart) {
    return PL011UartRead (PL011_UART_REGISTER_BASE, Buffer, NumberOfBytes);
  } else {
    if (NULL == Buffer) {
      return 0;
    }

    SerialRegisterBase = MINI_UART_REGISTER_BASE;

    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 aserial 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;

  if (UsePl011Uart) {
    return PL011UartPoll (PL011_UART_REGISTER_BASE);
  } else {
    SerialRegisterBase = MINI_UART_REGISTER_BASE;

    //
    // 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;

  if (UsePl011Uart) {
    return PL011UartSetControl (PL011_UART_REGISTER_BASE, Control);
  } else {
    //
    // 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 = MINI_UART_REGISTER_BASE;

    //
    // 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;

  if (UsePl011Uart) {
    return PL011UartGetControl (PL011_UART_REGISTER_BASE, Control);
  } else {
    SerialRegisterBase = MINI_UART_REGISTER_BASE;

    *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/receice 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 ReveiveFifoDepth   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
                            vaule 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;

  if (UsePl011Uart) {
    return PL011UartInitializePort (
             PL011_UART_REGISTER_BASE,
             PL011UartClockGetFreq(),
             BaudRate,
             ReceiveFifoDepth,
             Parity,
             DataBits,
             StopBits
             );
  } else {
    SerialRegisterBase = MINI_UART_REGISTER_BASE;

    //
    // 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;
      }
    }

    //
    // Configure baud rate
    //
    Divisor = SerialPortGetDivisor (SerialBaudRate);
    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;
  }
}