diff options
Diffstat (limited to 'CorebootPayloadPkg/Library/SerialPortLib/SerialPortLib.c')
| -rw-r--r-- | CorebootPayloadPkg/Library/SerialPortLib/SerialPortLib.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/CorebootPayloadPkg/Library/SerialPortLib/SerialPortLib.c b/CorebootPayloadPkg/Library/SerialPortLib/SerialPortLib.c new file mode 100644 index 0000000000..0d87e62b1b --- /dev/null +++ b/CorebootPayloadPkg/Library/SerialPortLib/SerialPortLib.c @@ -0,0 +1,316 @@ +/** @file
+ SerialPortLib instance for UART device upon coreboot
+
+ Copyright (c) 2014, Intel Corporation. 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/UefiBaseType.h>
+#include <Library/SerialPortLib.h>
+#include <Library/PcdLib.h>
+#include <Library/IoLib.h>
+#include <Library/CbParseLib.h>
+
+//
+// 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_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
+
+UINT32 mSerialRegBase = 0;
+UINT32 mSerialRegAccessType = 0;
+
+/**
+ 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 Offset The offset of the 16550 register to read.
+
+ @return The value read from the 16550 register.
+
+**/
+UINT8
+SerialPortReadRegister (
+ UINTN Offset
+ )
+{
+ if (mSerialRegAccessType == 2) { //MMIO
+ return MmioRead8 (mSerialRegBase + Offset);
+ } else { //IO
+ return IoRead8 ((UINT16)mSerialRegBase + Offset);
+ }
+}
+
+/**
+ 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 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 Offset,
+ UINT8 Value
+ )
+{
+ if (mSerialRegAccessType == 2) { //MMIO
+ return MmioWrite8 (mSerialRegBase + Offset, Value);
+ } else {// IO
+ return IoWrite8 ((UINT16)mSerialRegBase + Offset, Value);
+ }
+}
+
+/**
+ 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 Divisor;
+ BOOLEAN Initialized;
+
+ Status = CbParseSerialInfo (&mSerialRegBase, &mSerialRegAccessType, NULL);
+ if (RETURN_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // See if the serial port is already initialized
+ //
+ Initialized = TRUE;
+ if ((SerialPortReadRegister (R_UART_FCR) & (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64)) !=
+ (PcdGet8 (PcdSerialFifoControl) & (B_UART_FCR_FIFOE | B_UART_FCR_FIFO64)) ) {
+ Initialized = FALSE;
+ }
+
+ if ((SerialPortReadRegister (R_UART_LCR) & 0x3F) != (PcdGet8 (PcdSerialLineControl) & 0x3F)) {
+ Initialized = FALSE;
+ }
+ SerialPortWriteRegister (R_UART_LCR, (UINT8)(SerialPortReadRegister (R_UART_LCR) | B_UART_LCR_DLAB));
+ Divisor = SerialPortReadRegister (R_UART_BAUD_HIGH) << 8;
+ Divisor |= SerialPortReadRegister (R_UART_BAUD_LOW);
+ SerialPortWriteRegister (R_UART_LCR, (UINT8)(SerialPortReadRegister (R_UART_LCR) & ~B_UART_LCR_DLAB));
+ if (Divisor != 115200 / PcdGet32 (PcdSerialBaudRate)) {
+ Initialized = FALSE;
+ }
+ if (Initialized) {
+ return RETURN_SUCCESS;
+ }
+
+ //
+ // Configure baud rate
+ //
+ Divisor = 115200 / PcdGet32 (PcdSerialBaudRate);
+ SerialPortWriteRegister (R_UART_LCR, B_UART_LCR_DLAB);
+ SerialPortWriteRegister (R_UART_BAUD_HIGH, (UINT8) (Divisor >> 8));
+ SerialPortWriteRegister (R_UART_BAUD_LOW, (UINT8) (Divisor & 0xff));
+
+ //
+ // Clear DLAB and configure Data Bits, Parity, and Stop Bits.
+ // Strip reserved bits from PcdSerialLineControl
+ //
+ SerialPortWriteRegister (R_UART_LCR, (UINT8)(PcdGet8 (PcdSerialLineControl) & 0x3F));
+
+ //
+ // Enable and reset FIFOs
+ // Strip reserved bits from PcdSerialFifoControl
+ //
+ SerialPortWriteRegister (R_UART_FCR, (UINT8)(PcdGet8 (PcdSerialFifoControl) & 0x27));
+
+ //
+ // Put Modem Control Register(MCR) into its reset state of 0x00.
+ //
+ SerialPortWriteRegister (R_UART_MCR, 0x00);
+
+ 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 read operation failed.
+
+**/
+UINTN
+EFIAPI
+SerialPortWrite (
+ IN UINT8 *Buffer,
+ IN UINTN NumberOfBytes
+)
+{
+ UINTN Result;
+ UINTN Index;
+ UINTN FifoSize;
+
+ if (Buffer == NULL) {
+ return 0;
+ }
+
+ if (NumberOfBytes == 0) {
+ //
+ // Flush the hardware
+ //
+
+ //
+ // Wait for both the transmit FIFO and shift register empty.
+ //
+ while ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_TEMT) == 0);
+
+ 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 = 64;
+ }
+ }
+
+ 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 (R_UART_LSR) & B_UART_LSR_TEMT) == 0);
+
+ //
+ // Fill then entire Tx FIFO
+ //
+ for (Index = 0; Index < FifoSize && NumberOfBytes != 0; Index++, NumberOfBytes--, Buffer++) {
+
+ //
+ // Write byte to the transmit buffer.
+ //
+ SerialPortWriteRegister (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 Result;
+
+ if (NULL == Buffer) {
+ return 0;
+ }
+
+ for (Result = 0; NumberOfBytes-- != 0; Result++, Buffer++) {
+ //
+ // Wait for the serial port to have some data.
+ //
+ while ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_RXRDY) == 0);
+
+ //
+ // Read byte from the receive buffer.
+ //
+ *Buffer = SerialPortReadRegister (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
+ )
+{
+ //
+ // Read the serial port status
+ //
+ if ((SerialPortReadRegister (R_UART_LSR) & B_UART_LSR_RXRDY) != 0) {
+ return TRUE;
+ }
+
+ return FALSE;
+}
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