ArmVirtPkg/Library/FdtPL011SerialPortLib/EarlyFdtPL011SerialPortLib.c

   1 /** @file
   2   Serial I/O Port library functions with base address discovered from FDT
   3
   4   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   5   Copyright (c) 2012 - 2013, ARM Ltd. All rights reserved.<BR>
   6   Copyright (c) 2014, Linaro Ltd. All rights reserved.<BR>
   7   Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
   8
   9   This program and the accompanying materials
  10   are licensed and made available under the terms and conditions of the BSD License
  11   which accompanies this distribution.  The full text of the license may be found at
  12   http://opensource.org/licenses/bsd-license.php
  13
  14   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  15   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16
  17 **/
  18
  19 #include <Base.h>
  20
  21 #include <Library/PcdLib.h>
  22 #include <Library/SerialPortLib.h>
  23 #include <libfdt.h>
  24
  25 #include <Drivers/PL011Uart.h>
  26
  27 RETURN_STATUS
  28 EFIAPI
  29 SerialPortInitialize (
  30   VOID
  31   )
  32 {
  33   //
  34   // This SerialPortInitialize() function is completely empty, for a number of
  35   // reasons:
  36   // - if we are executing from flash, it is hard to keep state (i.e., store the
  37   //   discovered base address in a global), and the most robust way to deal
  38   //   with this is to discover the base address at every Write ();
  39   // - calls to the Write() function in this module may be issued before this
  40   //   initialization function is called: this is not a problem when the base
  41   //   address of the UART is hardcoded, and only the baud rate may be wrong,
  42   //   but if we don't know the base address yet, we may be poking into memory
  43   //   that does not tolerate being poked into;
  44   // - SEC and PEI phases produce debug output only, so with debug disabled, no
  45   //   initialization (or device tree parsing) is performed at all.
  46   //
  47   // Note that this means that on *every* Write () call, the device tree will be
  48   // parsed and the UART re-initialized. However, this is a small price to pay
  49   // for having serial debug output on a UART with no fixed base address.
  50   //
  51   return RETURN_SUCCESS;
  52 }
  53
  54 STATIC
  55 UINT64
  56 SerialPortGetBaseAddress (
  57   VOID
  58   )
  59 {
  60   UINT64              BaudRate;
  61   UINT32              ReceiveFifoDepth;
  62   EFI_PARITY_TYPE     Parity;
  63   UINT8               DataBits;
  64   EFI_STOP_BITS_TYPE  StopBits;
  65   VOID                *DeviceTreeBase;
  66   INT32               Node, Prev;
  67   INT32               Len;
  68   CONST CHAR8         *Compatible;
  69   CONST CHAR8         *NodeStatus;
  70   CONST CHAR8         *CompatibleItem;
  71   CONST UINT64        *RegProperty;
  72   UINTN               UartBase;
  73   RETURN_STATUS       Status;
  74
  75   DeviceTreeBase = (VOID *)(UINTN)PcdGet64 (PcdDeviceTreeInitialBaseAddress);
  76
  77   if ((DeviceTreeBase == NULL) || (fdt_check_header (DeviceTreeBase) != 0)) {
  78     return 0;
  79   }
  80
  81   //
  82   // Enumerate all FDT nodes looking for a PL011 and capture its base address
  83   //
  84   for (Prev = 0;; Prev = Node) {
  85     Node = fdt_next_node (DeviceTreeBase, Prev, NULL);
  86     if (Node < 0) {
  87       break;
  88     }
  89
  90     Compatible = fdt_getprop (DeviceTreeBase, Node, "compatible", &Len);
  91     if (Compatible == NULL) {
  92       continue;
  93     }
  94
  95     //
  96     // Iterate over the NULL-separated items in the compatible string
  97     //
  98     for (CompatibleItem = Compatible; CompatibleItem < Compatible + Len;
  99       CompatibleItem += 1 + AsciiStrLen (CompatibleItem)) {
 100
 101       if (AsciiStrCmp (CompatibleItem, "arm,pl011") == 0) {
 102         NodeStatus = fdt_getprop (DeviceTreeBase, Node, "status", &Len);
 103         if (NodeStatus != NULL && AsciiStrCmp (NodeStatus, "okay") != 0) {
 104           continue;
 105         }
 106
 107         RegProperty = fdt_getprop (DeviceTreeBase, Node, "reg", &Len);
 108         if (Len != 16) {
 109           return 0;
 110         }
 111         UartBase = (UINTN)fdt64_to_cpu (ReadUnaligned64 (RegProperty));
 112
 113         BaudRate = (UINTN)FixedPcdGet64 (PcdUartDefaultBaudRate);
 114         ReceiveFifoDepth = 0; // Use the default value for Fifo depth
 115         Parity = (EFI_PARITY_TYPE)FixedPcdGet8 (PcdUartDefaultParity);
 116         DataBits = FixedPcdGet8 (PcdUartDefaultDataBits);
 117         StopBits = (EFI_STOP_BITS_TYPE) FixedPcdGet8 (PcdUartDefaultStopBits);
 118
 119         Status = PL011UartInitializePort (
 120                    UartBase,
 121                    FixedPcdGet32 (PL011UartClkInHz),
 122                    &BaudRate,
 123                    &ReceiveFifoDepth,
 124                    &Parity,
 125                    &DataBits,
 126                    &StopBits
 127                    );
 128         if (!EFI_ERROR (Status)) {
 129           return UartBase;
 130         }
 131       }
 132     }
 133   }
 134   return 0;
 135 }
 136
 137 /**
 138   Write data to serial device.
 139
 140   @param  Buffer           Point of data buffer which need to be written.
 141   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
 142
 143   @retval 0                Write data failed.
 144   @retval !0               Actual number of bytes written to serial device.
 145
 146 **/
 147 UINTN
 148 EFIAPI
 149 SerialPortWrite (
 150   IN UINT8     *Buffer,
 151   IN UINTN     NumberOfBytes
 152   )
 153 {
 154   UINT64 SerialRegisterBase;
 155
 156   SerialRegisterBase = SerialPortGetBaseAddress ();
 157   if (SerialRegisterBase != 0) {
 158     return PL011UartWrite ((UINTN)SerialRegisterBase, Buffer, NumberOfBytes);
 159   }
 160   return 0;
 161 }
 162
 163 /**
 164   Read data from serial device and save the data in buffer.
 165
 166   @param  Buffer           Point of data buffer which need to be written.
 167   @param  NumberOfBytes    Size of Buffer[].
 168
 169   @retval 0                Read data failed.
 170   @retval !0               Actual number of bytes read from serial device.
 171
 172 **/
 173 UINTN
 174 EFIAPI
 175 SerialPortRead (
 176   OUT UINT8     *Buffer,
 177   IN  UINTN     NumberOfBytes
 178 )
 179 {
 180   return 0;
 181 }
 182
 183 /**
 184   Check to see if any data is available to be read from the debug device.
 185
 186   @retval TRUE       At least one byte of data is available to be read
 187   @retval FALSE      No data is available to be read
 188
 189 **/
 190 BOOLEAN
 191 EFIAPI
 192 SerialPortPoll (
 193   VOID
 194   )
 195 {
 196   return FALSE;
 197 }
 198
 199 /**
 200   Sets the control bits on a serial device.
 201
 202   @param[in] Control            Sets the bits of Control that are settable.
 203
 204   @retval RETURN_SUCCESS        The new control bits were set on the serial device.
 205   @retval RETURN_UNSUPPORTED    The serial device does not support this operation.
 206   @retval RETURN_DEVICE_ERROR   The serial device is not functioning correctly.
 207
 208 **/
 209 RETURN_STATUS
 210 EFIAPI
 211 SerialPortSetControl (
 212   IN UINT32 Control
 213   )
 214 {
 215   return RETURN_UNSUPPORTED;
 216 }
 217
 218 /**
 219   Retrieve the status of the control bits on a serial device.
 220
 221   @param[out] Control           A pointer to return the current control signals from the serial device.
 222
 223   @retval RETURN_SUCCESS        The control bits were read from the serial device.
 224   @retval RETURN_UNSUPPORTED    The serial device does not support this operation.
 225   @retval RETURN_DEVICE_ERROR   The serial device is not functioning correctly.
 226
 227 **/
 228 RETURN_STATUS
 229 EFIAPI
 230 SerialPortGetControl (
 231   OUT UINT32 *Control
 232   )
 233 {
 234   return RETURN_UNSUPPORTED;
 235 }
 236
 237 /**
 238   Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
 239   data bits, and stop bits on a serial device.
 240
 241   @param BaudRate           The requested baud rate. A BaudRate value of 0 will use the
 242                             device's default interface speed.
 243                             On output, the value actually set.
 244   @param ReveiveFifoDepth   The requested depth of the FIFO on the receive side of the
 245                             serial interface. A ReceiveFifoDepth value of 0 will use
 246                             the device's default FIFO depth.
 247                             On output, the value actually set.
 248   @param Timeout            The requested time out for a single character in microseconds.
 249                             This timeout applies to both the transmit and receive side of the
 250                             interface. A Timeout value of 0 will use the device's default time
 251                             out value.
 252                             On output, the value actually set.
 253   @param Parity             The type of parity to use on this serial device. A Parity value of
 254                             DefaultParity will use the device's default parity value.
 255                             On output, the value actually set.
 256   @param DataBits           The number of data bits to use on the serial device. A DataBits
 257                             vaule of 0 will use the device's default data bit setting.
 258                             On output, the value actually set.
 259   @param StopBits           The number of stop bits to use on this serial device. A StopBits
 260                             value of DefaultStopBits will use the device's default number of
 261                             stop bits.
 262                             On output, the value actually set.
 263
 264   @retval RETURN_SUCCESS            The new attributes were set on the serial device.
 265   @retval RETURN_UNSUPPORTED        The serial device does not support this operation.
 266   @retval RETURN_INVALID_PARAMETER  One or more of the attributes has an unsupported value.
 267   @retval RETURN_DEVICE_ERROR       The serial device is not functioning correctly.
 268
 269 **/
 270 RETURN_STATUS
 271 EFIAPI
 272 SerialPortSetAttributes (
 273   IN OUT UINT64             *BaudRate,
 274   IN OUT UINT32             *ReceiveFifoDepth,
 275   IN OUT UINT32             *Timeout,
 276   IN OUT EFI_PARITY_TYPE    *Parity,
 277   IN OUT UINT8              *DataBits,
 278   IN OUT EFI_STOP_BITS_TYPE *StopBits
 279   )
 280 {
 281   return RETURN_UNSUPPORTED;
 282 }
 283