[mirror_edk2.git] / MdeModulePkg / Library / BaseSerialPortLib16550 / BaseSerialPortLib16550.c

/** @file\r
  16550 UART Serial Port library functions\r
\r
  Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include <Base.h>\r
#include <Library/SerialPortLib.h>\r
#include <Library/PcdLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/PlatformHookLib.h>\r
\r
//\r
// 16550 UART register offsets and bitfields\r
//\r
#define R_UART_RXBUF          0\r
#define R_UART_TXBUF          0\r
#define R_UART_BAUD_LOW       0\r
#define R_UART_BAUD_HIGH      1\r
#define R_UART_FCR            2\r
#define   B_UART_FCR_FIFOE    BIT0\r
#define   B_UART_FCR_FIFO64   BIT5\r
#define R_UART_LCR            3\r
#define   B_UART_LCR_DLAB     BIT7\r
#define R_UART_MCR            4\r
#define   B_UART_MCR_RTS      BIT1\r
#define R_UART_LSR            5\r
#define   B_UART_LSR_RXRDY    BIT0\r
#define   B_UART_LSR_TXRDY    BIT5\r
#define   B_UART_LSR_TEMT     BIT6\r
#define R_UART_MSR            6\r
#define   B_UART_MSR_CTS      BIT4\r
#define   B_UART_MSR_DSR      BIT5\r
\r
/**\r
  Read an 8-bit 16550 register.  If PcdSerialUseMmio is TRUE, then the value is read from \r
  MMIO space.  If PcdSerialUseMmio is FALSE, then the value is read from I/O space.  The\r
  parameter Offset is added to the base address of the 16550 registers that is specified \r
  by PcdSerialRegisterBase. \r
  \r
  @param  Offset  The offset of the 16550 register to read.\r
\r
  @return The value read from the 16550 register.\r
\r
**/\r
UINT8\r
SerialPortReadRegister (\r
  UINTN  Offset\r
  )\r
{\r
  if (PcdGetBool (PcdSerialUseMmio)) {\r
    return MmioRead8 ((UINTN)PcdGet64 (PcdSerialRegisterBase) + Offset);\r
  } else {\r
    return IoRead8 ((UINT16)PcdGet64 (PcdSerialRegisterBase) + Offset);\r
  }\r
}\r
\r
/**\r
  Write an 8-bit 16550 register.  If PcdSerialUseMmio is TRUE, then the value is written to\r
  MMIO space.  If PcdSerialUseMmio is FALSE, then the value is written to I/O space.  The\r
  parameter Offset is added to the base address of the 16550 registers that is specified \r
  by PcdSerialRegisterBase. \r
  \r
  @param  Offset  The offset of the 16550 register to write.\r
  @param  Value   The value to write to the 16550 register specified by Offset.\r
\r
  @return The value written to the 16550 register.\r
\r
**/\r
UINT8\r
SerialPortWriteRegister (\r
  UINTN  Offset,\r
  UINT8  Value\r
  )\r
{\r
  if (PcdGetBool (PcdSerialUseMmio)) {\r
    return MmioWrite8 ((UINTN)PcdGet64 (PcdSerialRegisterBase) + Offset, Value);\r
  } else {\r
    return IoWrite8 ((UINT16)PcdGet64 (PcdSerialRegisterBase) + Offset, Value);\r
  }\r
}\r
\r
/**\r
  Initialize the serial device hardware.\r
  \r
  If no initialization is required, then return RETURN_SUCCESS.\r
  If the serial device was successfuly initialized, then return RETURN_SUCCESS.\r
  If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.\r
  \r
  @retval RETURN_SUCCESS        The serial device was initialized.\r
  @retval RETURN_DEVICE_ERROR   The serial device could not be initialized.\r
\r
**/\r
RETURN_STATUS\r
EFIAPI\r
SerialPortInitialize (\r
  VOID\r
  )\r
{\r
  RETURN_STATUS  Status;\r
  UINTN          Divisor;\r
  BOOLEAN        Initialized;\r
\r
  //\r
  // Perform platform specific initialization required to enable use of the 16550 device\r
  // at the location specified by PcdSerialUseMmio and PcdSerialRegisterBase.\r
  //\r
  Status = PlatformHookSerialPortInitialize ();\r
  if (RETURN_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // See if the serial port is already initialized\r
  //\r
  Initialized = TRUE;\r
  if ((SerialPortReadRegister (R_UART_FCR) & (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64)) !=\r
      (PcdGet8 (PcdSerialFifoControl)      & (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64))     ) {\r
    Initialized = FALSE;\r
  }\r
  if ((SerialPortReadRegister (R_UART_LCR) & 0x3F) != (PcdGet8 (PcdSerialLineControl) & 0x3F)) {\r
    Initialized = FALSE;\r
  }\r
  SerialPortWriteRegister (R_UART_LCR, (UINT8)(SerialPortReadRegister (R_UART_LCR) | B_UART_LCR_DLAB));\r
  Divisor =  SerialPortReadRegister (R_UART_BAUD_HIGH) << 8;\r
  Divisor |= SerialPortReadRegister (R_UART_BAUD_LOW);\r
  SerialPortWriteRegister (R_UART_LCR, (UINT8)(SerialPortReadRegister (R_UART_LCR) & ~B_UART_LCR_DLAB));\r
  if (Divisor != 115200 / PcdGet32 (PcdSerialBaudRate)) {\r
    Initialized = FALSE;\r
  }\r
  if (Initialized) {\r
    return RETURN_SUCCESS;\r
  }\r
  \r
  //\r
  // Configure baud rate\r
  //\r
  Divisor = 115200 / PcdGet32 (PcdSerialBaudRate);\r
  SerialPortWriteRegister (R_UART_LCR, B_UART_LCR_DLAB);\r
  SerialPortWriteRegister (R_UART_BAUD_HIGH, (UINT8) (Divisor >> 8));\r
  SerialPortWriteRegister (R_UART_BAUD_LOW, (UINT8) (Divisor & 0xff));\r
\r
  //\r
  // Clear DLAB and configure Data Bits, Parity, and Stop Bits.\r
  // Strip reserved bits from PcdSerialLineControl\r
  //\r
  SerialPortWriteRegister (R_UART_LCR, (UINT8)(PcdGet8 (PcdSerialLineControl) & 0x3F));\r
\r
  //\r
  // Enable and reset FIFOs\r
  // Strip reserved bits from PcdSerialFifoControl\r
  //\r
  SerialPortWriteRegister (R_UART_FCR, (UINT8)(PcdGet8 (PcdSerialFifoControl) & 0x27));\r
\r
  //\r
  // Put Modem Control Register(MCR) into its reset state of 0x00.\r
  //  \r
  SerialPortWriteRegister (R_UART_MCR, 0x00);\r
  \r
  return RETURN_SUCCESS;\r
}\r
\r
/**\r
  Write data from buffer to serial device. \r
 \r
  Writes NumberOfBytes data bytes from Buffer to the serial device.  \r
  The number of bytes actually written to the serial device is returned.\r
  If the return value is less than NumberOfBytes, then the write operation failed.\r
\r
  If Buffer is NULL, then ASSERT(). \r
\r
  If NumberOfBytes is zero, then return 0.\r
\r
  @param  Buffer           Pointer to the data buffer to be written.\r
  @param  NumberOfBytes    Number of bytes to written to the serial device.\r
\r
  @retval 0                NumberOfBytes is 0.\r
  @retval >0               The number of bytes written to the serial device.  \r
                           If this value is less than NumberOfBytes, then the read operation failed.\r
\r
**/\r
UINTN\r
EFIAPI\r
SerialPortWrite (\r
  IN UINT8     *Buffer,\r
  IN UINTN     NumberOfBytes\r
)\r
{\r
  UINTN    Result;\r
  UINTN    Index;\r
  UINTN    FifoSize;\r
\r
  if (Buffer == NULL) {\r
    return 0;\r
  }\r
\r
  //\r
  // Compute the maximum size of the Tx FIFO\r
  //\r
  FifoSize = 1;\r
  if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFOE) != 0) {\r
    if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFO64) == 0) {\r
      FifoSize = 16;\r
    } else {\r
      FifoSize = 64;\r
    }\r
  }\r
\r
  Result = NumberOfBytes;\r
  while (NumberOfBytes != 0) {\r
    //\r
    // Wait for the serial port to be ready, to make sure both the transmit FIFO\r
    // and shift register empty.\r
    //\r
    while ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_TEMT) == 0);\r
\r
    //\r
    // Fill then entire Tx FIFO\r
    //\r
    for (Index = 0; Index < FifoSize && NumberOfBytes != 0; Index++, NumberOfBytes--, Buffer++) {\r
      if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
        if (PcdGetBool (PcdSerialDetectCable)) {\r
          //\r
          // Wait for both DSR and CTS to be set\r
          //   DSR is set if a cable is connected.\r
          //   CTS is set if it is ok to transmit data\r
          //\r
          //   DSR  CTS  Description                               Action\r
          //   ===  ===  ========================================  ========\r
          //    0    0   No cable connected.                       Wait\r
          //    0    1   No cable connected.                       Wait\r
          //    1    0   Cable connected, but not clear to send.   Wait\r
          //    1    1   Cable connected, and clear to send.       Transmit\r
          //\r
          while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) != (B_UART_MSR_DSR | B_UART_MSR_CTS));\r
        } else {\r
          //\r
          // Wait for both DSR and CTS to be set OR for DSR to be clear.  \r
          //   DSR is set if a cable is connected.\r
          //   CTS is set if it is ok to transmit data\r
          //\r
          //   DSR  CTS  Description                               Action\r
          //   ===  ===  ========================================  ========\r
          //    0    0   No cable connected.                       Transmit\r
          //    0    1   No cable connected.                       Transmit\r
          //    1    0   Cable connected, but not clear to send.   Wait\r
          //    1    1   Cable connected, and clar to send.        Transmit\r
          //\r
          while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) == (B_UART_MSR_DSR));\r
        }\r
      }\r
      \r
      //\r
      // Write byte to the transmit buffer.\r
      //\r
      SerialPortWriteRegister (R_UART_TXBUF, *Buffer);\r
    }\r
  }\r
  return Result;\r
}\r
\r
/**\r
  Reads data from a serial device into a buffer.\r
\r
  @param  Buffer           Pointer to the data buffer to store the data read from the serial device.\r
  @param  NumberOfBytes    Number of bytes to read from the serial device.\r
\r
  @retval 0                NumberOfBytes is 0.\r
  @retval >0               The number of bytes read from the serial device.  \r
                           If this value is less than NumberOfBytes, then the read operation failed.\r
\r
**/\r
UINTN\r
EFIAPI\r
SerialPortRead (\r
  OUT UINT8     *Buffer,\r
  IN  UINTN     NumberOfBytes\r
)\r
{\r
  UINTN  Result;\r
  UINT8  Mcr;\r
\r
  if (NULL == Buffer) {\r
    return 0;\r
  }\r
\r
  Mcr = (UINT8)(SerialPortReadRegister (R_UART_MCR) & ~B_UART_MCR_RTS);\r
  \r
  for (Result = 0; NumberOfBytes-- != 0; Result++, Buffer++) {\r
    //\r
    // Wait for the serial port to have some data.\r
    //\r
    while ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_RXRDY) == 0) {\r
      if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
        //\r
        // Set RTS to let the peer send some data\r
        //\r
        SerialPortWriteRegister (R_UART_MCR, (UINT8)(Mcr | B_UART_MCR_RTS));\r
      }\r
    }\r
    if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
      //\r
      // Clear RTS to prevent peer from sending data\r
      //\r
      SerialPortWriteRegister (R_UART_MCR, Mcr);\r
    }\r
    \r
    //\r
    // Read byte from the receive buffer.\r
    //\r
    *Buffer = SerialPortReadRegister (R_UART_RXBUF);\r
  }\r
  \r
  return Result;\r
}\r
\r
/**\r
  Polls a serial device to see if there is any data waiting to be read.\r
\r
  Polls aserial device to see if there is any data waiting to be read.\r
  If there is data waiting to be read from the serial device, then TRUE is returned.\r
  If there is no data waiting to be read from the serial device, then FALSE is returned.\r
\r
  @retval TRUE             Data is waiting to be read from the serial device.\r
  @retval FALSE            There is no data waiting to be read from the serial device.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
SerialPortPoll (\r
  VOID\r
  )\r
{\r
  //\r
  // Read the serial port status\r
  //\r
  if ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_RXRDY) != 0) {\r
    if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
      //\r
      // Clear RTS to prevent peer from sending data\r
      //\r
      SerialPortWriteRegister (R_UART_MCR, (UINT8)(SerialPortReadRegister (R_UART_MCR) & ~B_UART_MCR_RTS));\r
    }\r
    return TRUE;\r
  }    \r
  \r
  if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
    //\r
    // Set RTS to let the peer send some data\r
    //\r
    SerialPortWriteRegister (R_UART_MCR, (UINT8)(SerialPortReadRegister (R_UART_MCR) | B_UART_MCR_RTS));\r
  }\r
  \r
  return FALSE;\r
}\r
Commit	Line	Data
467d15ae	1	/** @file\r
	2	16550 UART Serial Port library functions\r
	3	\r
db662a64	4	Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>\r
467d15ae	5	This program and the accompanying materials\r
	6	are licensed and made available under the terms and conditions of the BSD License\r
	7	which accompanies this distribution. The full text of the license may be found at\r
	8	http://opensource.org/licenses/bsd-license.php\r
	9	\r
	10	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	11	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	12	\r
	13	**/\r
	14	\r
	15	#include <Base.h>\r
	16	#include <Library/SerialPortLib.h>\r
	17	#include <Library/PcdLib.h>\r
	18	#include <Library/IoLib.h>\r
	19	#include <Library/PlatformHookLib.h>\r
	20	\r
	21	//\r
	22	// 16550 UART register offsets and bitfields\r
	23	//\r
	24	#define R_UART_RXBUF 0\r
	25	#define R_UART_TXBUF 0\r
	26	#define R_UART_BAUD_LOW 0\r
	27	#define R_UART_BAUD_HIGH 1\r
	28	#define R_UART_FCR 2\r
	29	#define B_UART_FCR_FIFOE BIT0\r
	30	#define B_UART_FCR_FIFO64 BIT5\r
	31	#define R_UART_LCR 3\r
	32	#define B_UART_LCR_DLAB BIT7\r
	33	#define R_UART_MCR 4\r
	34	#define B_UART_MCR_RTS BIT1\r
	35	#define R_UART_LSR 5\r
	36	#define B_UART_LSR_RXRDY BIT0\r
	37	#define B_UART_LSR_TXRDY BIT5\r
	38	#define B_UART_LSR_TEMT BIT6\r
	39	#define R_UART_MSR 6\r
	40	#define B_UART_MSR_CTS BIT4\r
784ce127	41	#define B_UART_MSR_DSR BIT5\r
467d15ae	42	\r
	43	/**\r
	44	Read an 8-bit 16550 register. If PcdSerialUseMmio is TRUE, then the value is read from \r
	45	MMIO space. If PcdSerialUseMmio is FALSE, then the value is read from I/O space. The\r
	46	parameter Offset is added to the base address of the 16550 registers that is specified \r
	47	by PcdSerialRegisterBase. \r
	48	\r
	49	@param Offset The offset of the 16550 register to read.\r
	50	\r
	51	@return The value read from the 16550 register.\r
	52	\r
	53	**/\r
	54	UINT8\r
	55	SerialPortReadRegister (\r
	56	UINTN Offset\r
	57	)\r
	58	{\r
	59	if (PcdGetBool (PcdSerialUseMmio)) {\r
	60	return MmioRead8 ((UINTN)PcdGet64 (PcdSerialRegisterBase) + Offset);\r
	61	} else {\r
	62	return IoRead8 ((UINT16)PcdGet64 (PcdSerialRegisterBase) + Offset);\r
	63	}\r
	64	}\r
	65	\r
	66	/**\r
	67	Write an 8-bit 16550 register. If PcdSerialUseMmio is TRUE, then the value is written to\r
	68	MMIO space. If PcdSerialUseMmio is FALSE, then the value is written to I/O space. The\r
	69	parameter Offset is added to the base address of the 16550 registers that is specified \r
	70	by PcdSerialRegisterBase. \r
	71	\r
e25fb2c0	72	@param Offset The offset of the 16550 register to write.\r
e25fb2c0	73	@param Value The value to write to the 16550 register specified by Offset.\r
467d15ae	74	\r
	75	@return The value written to the 16550 register.\r
	76	\r
	77	**/\r
	78	UINT8\r
	79	SerialPortWriteRegister (\r
	80	UINTN Offset,\r
	81	UINT8 Value\r
	82	)\r
	83	{\r
	84	if (PcdGetBool (PcdSerialUseMmio)) {\r
	85	return MmioWrite8 ((UINTN)PcdGet64 (PcdSerialRegisterBase) + Offset, Value);\r
	86	} else {\r
	87	return IoWrite8 ((UINT16)PcdGet64 (PcdSerialRegisterBase) + Offset, Value);\r
	88	}\r
	89	}\r
	90	\r
	91	/**\r
	92	Initialize the serial device hardware.\r
	93	\r
	94	If no initialization is required, then return RETURN_SUCCESS.\r
	95	If the serial device was successfuly initialized, then return RETURN_SUCCESS.\r
	96	If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.\r
	97	\r
	98	@retval RETURN_SUCCESS The serial device was initialized.\r
	99	@retval RETURN_DEVICE_ERROR The serial device could not be initialized.\r
	100	\r
	101	**/\r
	102	RETURN_STATUS\r
	103	EFIAPI\r
	104	SerialPortInitialize (\r
	105	VOID\r
	106	)\r
	107	{\r
	108	RETURN_STATUS Status;\r
	109	UINTN Divisor;\r
	110	BOOLEAN Initialized;\r
	111	\r
	112	//\r
	113	// Perform platform specific initialization required to enable use of the 16550 device\r
	114	// at the location specified by PcdSerialUseMmio and PcdSerialRegisterBase.\r
	115	//\r
	116	Status = PlatformHookSerialPortInitialize ();\r
	117	if (RETURN_ERROR (Status)) {\r
	118	return Status;\r
	119	}\r
	120	\r
	121	//\r
	122	// See if the serial port is already initialized\r
	123	//\r
	124	Initialized = TRUE;\r
	125	if ((SerialPortReadRegister (R_UART_FCR) & (B_UART_FCR_FIFOE \| B_UART_FCR_FIFO64)) !=\r
	126	(PcdGet8 (PcdSerialFifoControl) & (B_UART_FCR_FIFOE \| B_UART_FCR_FIFO64)) ) {\r
	127	Initialized = FALSE;\r
	128	}\r
	129	if ((SerialPortReadRegister (R_UART_LCR) & 0x3F) != (PcdGet8 (PcdSerialLineControl) & 0x3F)) {\r
	130	Initialized = FALSE;\r
	131	}\r
f2ad9497	132	SerialPortWriteRegister (R_UART_LCR, (UINT8)(SerialPortReadRegister (R_UART_LCR) \| B_UART_LCR_DLAB));\r
	133	Divisor = SerialPortReadRegister (R_UART_BAUD_HIGH) << 8;\r
	134	Divisor \|= SerialPortReadRegister (R_UART_BAUD_LOW);\r
	135	SerialPortWriteRegister (R_UART_LCR, (UINT8)(SerialPortReadRegister (R_UART_LCR) & ~B_UART_LCR_DLAB));\r
467d15ae	136	if (Divisor != 115200 / PcdGet32 (PcdSerialBaudRate)) {\r
	137	Initialized = FALSE;\r
	138	}\r
	139	if (Initialized) {\r
	140	return RETURN_SUCCESS;\r
	141	}\r
	142	\r
	143	//\r
	144	// Configure baud rate\r
	145	//\r
	146	Divisor = 115200 / PcdGet32 (PcdSerialBaudRate);\r
	147	SerialPortWriteRegister (R_UART_LCR, B_UART_LCR_DLAB);\r
	148	SerialPortWriteRegister (R_UART_BAUD_HIGH, (UINT8) (Divisor >> 8));\r
	149	SerialPortWriteRegister (R_UART_BAUD_LOW, (UINT8) (Divisor & 0xff));\r
	150	\r
	151	//\r
	152	// Clear DLAB and configure Data Bits, Parity, and Stop Bits.\r
	153	// Strip reserved bits from PcdSerialLineControl\r
	154	//\r
f2ad9497	155	SerialPortWriteRegister (R_UART_LCR, (UINT8)(PcdGet8 (PcdSerialLineControl) & 0x3F));\r
467d15ae	156	\r
	157	//\r
	158	// Enable and reset FIFOs\r
	159	// Strip reserved bits from PcdSerialFifoControl\r
	160	//\r
acaa2726	161	SerialPortWriteRegister (R_UART_FCR, (UINT8)(PcdGet8 (PcdSerialFifoControl) & 0x27));\r
467d15ae	162	\r
	163	//\r
	164	// Put Modem Control Register(MCR) into its reset state of 0x00.\r
	165	// \r
	166	SerialPortWriteRegister (R_UART_MCR, 0x00);\r
	167	\r
	168	return RETURN_SUCCESS;\r
	169	}\r
	170	\r
	171	/**\r
	172	Write data from buffer to serial device. \r
	173	\r
	174	Writes NumberOfBytes data bytes from Buffer to the serial device. \r
	175	The number of bytes actually written to the serial device is returned.\r
	176	If the return value is less than NumberOfBytes, then the write operation failed.\r
	177	\r
	178	If Buffer is NULL, then ASSERT(). \r
	179	\r
	180	If NumberOfBytes is zero, then return 0.\r
	181	\r
	182	@param Buffer Pointer to the data buffer to be written.\r
	183	@param NumberOfBytes Number of bytes to written to the serial device.\r
	184	\r
	185	@retval 0 NumberOfBytes is 0.\r
	186	@retval >0 The number of bytes written to the serial device. \r
	187	If this value is less than NumberOfBytes, then the read operation failed.\r
	188	\r
	189	**/\r
	190	UINTN\r
	191	EFIAPI\r
	192	SerialPortWrite (\r
	193	IN UINT8 *Buffer,\r
	194	IN UINTN NumberOfBytes\r
	195	)\r
	196	{\r
db662a64	197	UINTN Result;\r
	198	UINTN Index;\r
	199	UINTN FifoSize;\r
467d15ae	200	\r
	201	if (Buffer == NULL) {\r
	202	return 0;\r
	203	}\r
	204	\r
	205	//\r
	206	// Compute the maximum size of the Tx FIFO\r
	207	//\r
	208	FifoSize = 1;\r
	209	if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFOE) != 0) {\r
	210	if ((PcdGet8 (PcdSerialFifoControl) & B_UART_FCR_FIFO64) == 0) {\r
	211	FifoSize = 16;\r
	212	} else {\r
	213	FifoSize = 64;\r
	214	}\r
	215	}\r
db662a64	216	\r
467d15ae	217	Result = NumberOfBytes;\r
	218	while (NumberOfBytes != 0) {\r
	219	//\r
	220	// Wait for the serial port to be ready, to make sure both the transmit FIFO\r
	221	// and shift register empty.\r
	222	//\r
	223	while ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_TEMT) == 0);\r
	224	\r
	225	//\r
	226	// Fill then entire Tx FIFO\r
	227	//\r
	228	for (Index = 0; Index < FifoSize && NumberOfBytes != 0; Index++, NumberOfBytes--, Buffer++) {\r
	229	if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
784ce127	230	if (PcdGetBool (PcdSerialDetectCable)) {\r
	231	//\r
	232	// Wait for both DSR and CTS to be set\r
	233	// DSR is set if a cable is connected.\r
	234	// CTS is set if it is ok to transmit data\r
	235	//\r
	236	// DSR CTS Description Action\r
	237	// === === ======================================== ========\r
	238	// 0 0 No cable connected. Wait\r
	239	// 0 1 No cable connected. Wait\r
	240	// 1 0 Cable connected, but not clear to send. Wait\r
	241	// 1 1 Cable connected, and clear to send. Transmit\r
	242	//\r
	243	while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_DSR \| B_UART_MSR_CTS)) != (B_UART_MSR_DSR \| B_UART_MSR_CTS));\r
	244	} else {\r
	245	//\r
	246	// Wait for both DSR and CTS to be set OR for DSR to be clear. \r
	247	// DSR is set if a cable is connected.\r
	248	// CTS is set if it is ok to transmit data\r
	249	//\r
	250	// DSR CTS Description Action\r
	251	// === === ======================================== ========\r
	252	// 0 0 No cable connected. Transmit\r
	253	// 0 1 No cable connected. Transmit\r
	254	// 1 0 Cable connected, but not clear to send. Wait\r
	255	// 1 1 Cable connected, and clar to send. Transmit\r
	256	//\r
	257	while ((SerialPortReadRegister (R_UART_MSR) & (B_UART_MSR_DSR \| B_UART_MSR_CTS)) == (B_UART_MSR_DSR));\r
	258	}\r
467d15ae	259	}\r
	260	\r
	261	//\r
	262	// Write byte to the transmit buffer.\r
	263	//\r
	264	SerialPortWriteRegister (R_UART_TXBUF, *Buffer);\r
	265	}\r
	266	}\r
	267	return Result;\r
	268	}\r
	269	\r
	270	/**\r
	271	Reads data from a serial device into a buffer.\r
	272	\r
	273	@param Buffer Pointer to the data buffer to store the data read from the serial device.\r
	274	@param NumberOfBytes Number of bytes to read from the serial device.\r
	275	\r
	276	@retval 0 NumberOfBytes is 0.\r
	277	@retval >0 The number of bytes read from the serial device. \r
	278	If this value is less than NumberOfBytes, then the read operation failed.\r
	279	\r
	280	**/\r
	281	UINTN\r
	282	EFIAPI\r
	283	SerialPortRead (\r
	284	OUT UINT8 *Buffer,\r
	285	IN UINTN NumberOfBytes\r
	286	)\r
	287	{\r
	288	UINTN Result;\r
	289	UINT8 Mcr;\r
	290	\r
	291	if (NULL == Buffer) {\r
	292	return 0;\r
	293	}\r
	294	\r
f2ad9497	295	Mcr = (UINT8)(SerialPortReadRegister (R_UART_MCR) & ~B_UART_MCR_RTS);\r
467d15ae	296	\r
	297	for (Result = 0; NumberOfBytes-- != 0; Result++, Buffer++) {\r
	298	//\r
	299	// Wait for the serial port to have some data.\r
	300	//\r
	301	while ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_RXRDY) == 0) {\r
	302	if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
	303	//\r
	304	// Set RTS to let the peer send some data\r
	305	//\r
f2ad9497	306	SerialPortWriteRegister (R_UART_MCR, (UINT8)(Mcr \| B_UART_MCR_RTS));\r
467d15ae	307	}\r
	308	}\r
	309	if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
	310	//\r
	311	// Clear RTS to prevent peer from sending data\r
	312	//\r
	313	SerialPortWriteRegister (R_UART_MCR, Mcr);\r
	314	}\r
	315	\r
	316	//\r
	317	// Read byte from the receive buffer.\r
	318	//\r
	319	*Buffer = SerialPortReadRegister (R_UART_RXBUF);\r
	320	}\r
	321	\r
	322	return Result;\r
	323	}\r
	324	\r
	325	/**\r
	326	Polls a serial device to see if there is any data waiting to be read.\r
	327	\r
	328	Polls aserial device to see if there is any data waiting to be read.\r
	329	If there is data waiting to be read from the serial device, then TRUE is returned.\r
	330	If there is no data waiting to be read from the serial device, then FALSE is returned.\r
	331	\r
	332	@retval TRUE Data is waiting to be read from the serial device.\r
	333	@retval FALSE There is no data waiting to be read from the serial device.\r
	334	\r
	335	**/\r
	336	BOOLEAN\r
	337	EFIAPI\r
	338	SerialPortPoll (\r
	339	VOID\r
	340	)\r
	341	{\r
	342	//\r
	343	// Read the serial port status\r
	344	//\r
	345	if ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_RXRDY) != 0) {\r
	346	if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
	347	//\r
	348	// Clear RTS to prevent peer from sending data\r
	349	//\r
f2ad9497	350	SerialPortWriteRegister (R_UART_MCR, (UINT8)(SerialPortReadRegister (R_UART_MCR) & ~B_UART_MCR_RTS));\r
467d15ae	351	}\r
	352	return TRUE;\r
	353	} \r
	354	\r
	355	if (PcdGetBool (PcdSerialUseHardwareFlowControl)) {\r
	356	//\r
	357	// Set RTS to let the peer send some data\r
	358	//\r
f2ad9497	359	SerialPortWriteRegister (R_UART_MCR, (UINT8)(SerialPortReadRegister (R_UART_MCR) \| B_UART_MCR_RTS));\r
467d15ae	360	}\r
	361	\r
	362	return FALSE;\r
	363	}\r