diff options
Diffstat (limited to 'PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c')
-rw-r--r-- | PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c b/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c new file mode 100644 index 0000000000..f0cdc4982f --- /dev/null +++ b/PcAtChipsetPkg/Library/SerialIoLib/SerialPortLib.c @@ -0,0 +1,222 @@ +/** @file
+ UART Serial Port library instance with empty functions.
+
+ Copyright (c) 2006 - 2008, Intel Corporation
+ 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 <Base.h>
+
+#include <Library/SerialPortLib.h>
+#include <Library/IoLib.h>
+
+//---------------------------------------------
+// UART Register Offsets
+//---------------------------------------------
+#define BAUD_LOW_OFFSET 0x00
+#define BAUD_HIGH_OFFSET 0x01
+#define IER_OFFSET 0x01
+#define LCR_SHADOW_OFFSET 0x01
+#define FCR_SHADOW_OFFSET 0x02
+#define IR_CONTROL_OFFSET 0x02
+#define FCR_OFFSET 0x02
+#define EIR_OFFSET 0x02
+#define BSR_OFFSET 0x03
+#define LCR_OFFSET 0x03
+#define MCR_OFFSET 0x04
+#define LSR_OFFSET 0x05
+#define MSR_OFFSET 0x06
+
+//---------------------------------------------
+// UART Register Bit Defines
+//---------------------------------------------
+#define LSR_TXRDY 0x20
+#define LSR_RXDA 0x01
+#define DLAB 0x01
+
+//---------------------------------------------
+// UART Settings
+//---------------------------------------------
+UINT16 gUartBase = 0x3F8;
+UINTN gBps = 115200;
+UINT8 gData = 8;
+UINT8 gStop = 1;
+UINT8 gParity = 0;
+UINT8 gBreakSet = 0;
+
+/**
+ Initialize the serial device hardware.
+
+ If no initialization is required, then return RETURN_SUCCESS.
+ If the serial device was successfuly 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 serail device could not be initialized.
+
+**/
+RETURN_STATUS
+EFIAPI
+SerialPortInitialize (
+ VOID
+ )
+{
+ UINTN Divisor;
+ UINT8 OutputData;
+ UINT8 Data;
+
+ //
+ // Map 5..8 to 0..3
+ //
+ Data = (UINT8) (gData - (UINT8) 5);
+
+ //
+ // Calculate divisor for baud generator
+ //
+ Divisor = 115200 / gBps;
+
+ //
+ // Set communications format
+ //
+ OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);
+ IoWrite8 ((UINTN) (gUartBase + LCR_OFFSET), OutputData);
+
+ //
+ // Configure baud rate
+ //
+ IoWrite8 ((UINTN) (gUartBase + BAUD_HIGH_OFFSET), (UINT8) (Divisor >> 8));
+ IoWrite8 ((UINTN) (gUartBase + BAUD_LOW_OFFSET), (UINT8) (Divisor & 0xff));
+
+ //
+ // Switch back to bank 0
+ //
+ OutputData = (UINT8) ((~DLAB << 7) | (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);
+ IoWrite8 ((UINTN) (gUartBase + LCR_OFFSET), OutputData);
+
+ 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;
+ UINT8 Data;
+
+ if (Buffer == NULL) {
+ return 0;
+ }
+
+ Result = NumberOfBytes;
+
+ while (NumberOfBytes--) {
+ //
+ // Wait for the serail port to be ready.
+ //
+ do {
+ Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
+ } while ((Data & LSR_TXRDY) == 0);
+ IoWrite8 ((UINT16) gUartBase, *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;
+ UINT8 Data;
+
+ if (NULL == Buffer) {
+ return 0;
+ }
+
+ Result = NumberOfBytes;
+
+ while (NumberOfBytes--) {
+ //
+ // Wait for the serail port to be ready.
+ //
+ do {
+ Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
+ } while ((Data & LSR_RXDA) == 0);
+
+ *Buffer++ = IoRead8 ((UINT16) gUartBase);
+ }
+
+ 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
+ )
+{
+ UINT8 Data;
+
+ //
+ // Read the serial port status.
+ //
+ Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
+
+ return (BOOLEAN) ((Data & LSR_RXDA) != 0);
+}
+
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