[PATCH edk2-platforms 1/5] Platform/RaspberryPi/DualSerialPortLib: split up to ease reuse

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

In preparation of creating different versions of DualSerialPortLib,
split off the parts that will be shared between all versions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
---
 Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.inf     |   5 +-
 Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.h       |  82 +++++++
 Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c       | 229 +-------------------
 Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLibCommon.c | 218 +++++++++++++++++++
 4 files changed, 305 insertions(+), 229 deletions(-)

diff --git a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.inf b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.inf
index af1e6b026fe6..fda9ff2bcbf9 100644
--- a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.inf
+++ b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.inf
@@ -19,9 +19,8 @@ [Defines]
 
 [Packages]
   ArmPlatformPkg/ArmPlatformPkg.dec
-  EmbeddedPkg/EmbeddedPkg.dec
-  MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
   Silicon/Broadcom/Bcm283x/Bcm283x.dec
 
 [LibraryClasses]
@@ -32,6 +31,8 @@ [LibraryClasses]
 
 [Sources]
   DualSerialPortLib.c
+  DualSerialPortLib.h
+  DualSerialPortLibCommon.c
 
 [Pcd]
   gEfiMdeModulePkgTokenSpaceGuid.PcdSerialRegisterAccessWidth     ## SOMETIMES_CONSUMES
diff --git a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.h b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.h
new file mode 100644
index 000000000000..a8d150f516b9
--- /dev/null
+++ b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.h
@@ -0,0 +1,82 @@
+/** @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 <Uefi/UefiBaseType.h>
+#include <IndustryStandard/Bcm2836.h>
+#include <IndustryStandard/Bcm2836Gpio.h>
+
+#define PL011_UART_REGISTER_BASE      BCM2836_PL011_UART_BASE_ADDRESS
+#define MINI_UART_REGISTER_BASE       (BCM2836_MINI_UART_BASE_ADDRESS + 0x40)
+
+//
+// 16550 UART register offsets and bitfields
+//
+#define R_UART_RXBUF          0   // LCR_DLAB = 0
+#define R_UART_TXBUF          0   // LCR_DLAB = 0
+#define R_UART_BAUD_LOW       0   // LCR_DLAB = 1
+#define R_UART_BAUD_HIGH      1   // LCR_DLAB = 1
+#define R_UART_IER            1   // LCR_DLAB = 0
+#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
+
+extern BOOLEAN UsePl011Uart;
+extern BOOLEAN UsePl011UartSet;
+
+/**
+  Read an 8-bit 16550 register.
+
+  @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
+  );
+
+/**
+  Write an 8-bit 16550 register.
+
+  @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
+  );
+
diff --git a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c
index 05e12f383785..b1d17d3fa04a 100644
--- a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c
+++ b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLib.c
@@ -13,132 +13,13 @@
 **/
 
 #include <Base.h>
-#include <IndustryStandard/Bcm2836.h>
-#include <IndustryStandard/Bcm2836Gpio.h>
-#include <Library/BaseLib.h>
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
 #include <Library/PL011UartClockLib.h>
 #include <Library/PL011UartLib.h>
 #include <Library/SerialPortLib.h>
 
-BOOLEAN UsePl011Uart          = FALSE;
-BOOLEAN UsePl011UartSet       = FALSE;
-
-#define PL011_UART_REGISTER_BASE      BCM2836_PL011_UART_BASE_ADDRESS
-#define MINI_UART_REGISTER_BASE       (BCM2836_MINI_UART_BASE_ADDRESS + 0x40)
-
-//
-// 16550 UART register offsets and bitfields
-//
-#define R_UART_RXBUF          0   // LCR_DLAB = 0
-#define R_UART_TXBUF          0   // LCR_DLAB = 0
-#define R_UART_BAUD_LOW       0   // LCR_DLAB = 1
-#define R_UART_BAUD_HIGH      1   // LCR_DLAB = 1
-#define R_UART_IER            1   // LCR_DLAB = 0
-#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
-
-/**
-  Read an 8-bit 16550 register.
-
-  @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
-  )
-{
-  return MmioRead8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
-}
-
-/**
-  Write an 8-bit 16550 register.
-
-  @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
-  )
-{
-  return MmioWrite8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), Value);
-}
-
-/**
-  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 clar to send.        Transmit
-      //
-      return (BOOLEAN) ((SerialPortReadRegister (SerialRegisterBase, R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) != (B_UART_MSR_DSR));
-    }
-  }
-
-  return TRUE;
-}
+#include "DualSerialPortLib.h"
 
 /**
   Return the baud generator divisor to use for 16650 setup.
@@ -147,6 +28,7 @@ SerialPortWritable (
 
   @return The baud generator divisor.
 **/
+STATIC
 UINT32
 SerialPortGetDivisor (
   UINT32  SerialBaudRate
@@ -288,113 +170,6 @@ SerialPortInitialize (
   }
 }
 
-/**
-  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;
-
-  //
-  // Serial writes may happen *before* the UART has been initialized
-  // and if we use the wrong UART then, all kind of bad things happen.
-  // To alleviate this, we add UART detection in SerialPortWrite and
-  // guard the UART detection with a second boolean.
-  //
-  if (!UsePl011UartSet) {
-    UsePl011Uart = ((MmioRead32(GPIO_BASE_ADDRESS + 4) & 0x0003F000) == 0x00024000);
-    UsePl011UartSet = TRUE;
-  }
-
-  if (UsePl011Uart) {
-    return PL011UartWrite (PL011_UART_REGISTER_BASE, Buffer, NumberOfBytes);
-  } else {
-    if (Buffer == NULL) {
-      return 0;
-    }
-
-    SerialRegisterBase = MINI_UART_REGISTER_BASE;
-
-    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 | B_UART_LSR_TXRDY)) != (B_UART_LSR_TEMT | B_UART_LSR_TXRDY));
-
-      //
-      // 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.
 
diff --git a/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLibCommon.c b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLibCommon.c
new file mode 100644
index 000000000000..48d8df280640
--- /dev/null
+++ b/Platform/RaspberryPi/Library/DualSerialPortLib/DualSerialPortLibCommon.c
@@ -0,0 +1,218 @@
+/** @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/PL011UartLib.h>
+#include <Library/SerialPortLib.h>
+
+#include "DualSerialPortLib.h"
+
+BOOLEAN UsePl011Uart          = FALSE;
+BOOLEAN UsePl011UartSet       = FALSE;
+
+/**
+  Read an 8-bit 16550 register.
+
+  @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
+  )
+{
+  return MmioRead8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride));
+}
+
+/**
+  Write an 8-bit 16550 register.
+
+  @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
+  )
+{
+  return MmioWrite8 (Base + Offset * PcdGet32 (PcdSerialRegisterStride), Value);
+}
+
+/**
+  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.
+**/
+STATIC
+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 clar to send.        Transmit
+      //
+      return (BOOLEAN) ((SerialPortReadRegister (SerialRegisterBase, R_UART_MSR) & (B_UART_MSR_DSR | B_UART_MSR_CTS)) != (B_UART_MSR_DSR));
+    }
+  }
+
+  return TRUE;
+}
+
+/**
+  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;
+
+  //
+  // Serial writes may happen *before* the UART has been initialized
+  // and if we use the wrong UART then, all kind of bad things happen.
+  // To alleviate this, we add UART detection in SerialPortWrite and
+  // guard the UART detection with a second boolean.
+  //
+  if (!UsePl011UartSet) {
+    UsePl011Uart = ((MmioRead32(GPIO_BASE_ADDRESS + 4) & 0x0003F000) == 0x00024000);
+    UsePl011UartSet = TRUE;
+  }
+
+  if (UsePl011Uart) {
+    return PL011UartWrite (PL011_UART_REGISTER_BASE, Buffer, NumberOfBytes);
+  } else {
+    if (Buffer == NULL) {
+      return 0;
+    }
+
+    SerialRegisterBase = MINI_UART_REGISTER_BASE;
+
+    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 | B_UART_LSR_TXRDY)) != (B_UART_LSR_TEMT | B_UART_LSR_TXRDY));
+
+      //
+      // 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;
+  }
+}
-- 
2.17.1