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         *CompatibleItem;
  70   CONST UINT64        *RegProperty;
  71   UINTN               UartBase;
  72   RETURN_STATUS       Status;
  73
  74   DeviceTreeBase = (VOID *)(UINTN)PcdGet64 (PcdDeviceTreeInitialBaseAddress);
  75
  76   if ((DeviceTreeBase == NULL) || (fdt_check_header (DeviceTreeBase) != 0)) {
  77     return 0;
  78   }
  79
  80   //
  81   // Enumerate all FDT nodes looking for a PL011 and capture its base address
  82   //
  83   for (Prev = 0;; Prev = Node) {
  84     Node = fdt_next_node (DeviceTreeBase, Prev, NULL);
  85     if (Node < 0) {
  86       break;
  87     }
  88
  89     Compatible = fdt_getprop (DeviceTreeBase, Node, "compatible", &Len);
  90     if (Compatible == NULL) {
  91       continue;
  92     }
  93
  94     //
  95     // Iterate over the NULL-separated items in the compatible string
  96     //
  97     for (CompatibleItem = Compatible; CompatibleItem < Compatible + Len;
  98       CompatibleItem += 1 + AsciiStrLen (CompatibleItem)) {
  99
 100       if (AsciiStrCmp (CompatibleItem, "arm,pl011") == 0) {
 101         RegProperty = fdt_getprop (DeviceTreeBase, Node, "reg", &Len);
 102         if (Len != 16) {
 103           return 0;
 104         }
 105         UartBase = (UINTN)fdt64_to_cpu (ReadUnaligned64 (RegProperty));
 106
 107         BaudRate = (UINTN)FixedPcdGet64 (PcdUartDefaultBaudRate);
 108         ReceiveFifoDepth = 0; // Use the default value for Fifo depth
 109         Parity = (EFI_PARITY_TYPE)FixedPcdGet8 (PcdUartDefaultParity);
 110         DataBits = FixedPcdGet8 (PcdUartDefaultDataBits);
 111         StopBits = (EFI_STOP_BITS_TYPE) FixedPcdGet8 (PcdUartDefaultStopBits);
 112
 113         Status = PL011UartInitializePort (
 114                    UartBase,
 115                    FixedPcdGet32 (PL011UartClkInHz),
 116                    &BaudRate,
 117                    &ReceiveFifoDepth,
 118                    &Parity,
 119                    &DataBits,
 120                    &StopBits
 121                    );
 122         if (!EFI_ERROR (Status)) {
 123           return UartBase;
 124         }
 125       }
 126     }
 127   }
 128   return 0;
 129 }
 130
 131 /**
 132   Write data to serial device.
 133
 134   @param  Buffer           Point of data buffer which need to be written.
 135   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
 136
 137   @retval 0                Write data failed.
 138   @retval !0               Actual number of bytes written to serial device.
 139
 140 **/
 141 UINTN
 142 EFIAPI
 143 SerialPortWrite (
 144   IN UINT8     *Buffer,
 145   IN UINTN     NumberOfBytes
 146   )
 147 {
 148   UINT64 SerialRegisterBase;
 149
 150   SerialRegisterBase = SerialPortGetBaseAddress ();
 151   if (SerialRegisterBase != 0) {
 152     return PL011UartWrite ((UINTN)SerialRegisterBase, Buffer, NumberOfBytes);
 153   }
 154   return 0;
 155 }
 156
 157 /**
 158   Read data from serial device and save the data in buffer.
 159
 160   @param  Buffer           Point of data buffer which need to be written.
 161   @param  NumberOfBytes    Size of Buffer[].
 162
 163   @retval 0                Read data failed.
 164   @retval !0               Actual number of bytes read from serial device.
 165
 166 **/
 167 UINTN
 168 EFIAPI
 169 SerialPortRead (
 170   OUT UINT8     *Buffer,
 171   IN  UINTN     NumberOfBytes
 172 )
 173 {
 174   return 0;
 175 }
 176
 177 /**
 178   Check to see if any data is available to be read from the debug device.
 179
 180   @retval TRUE       At least one byte of data is available to be read
 181   @retval FALSE      No data is available to be read
 182
 183 **/
 184 BOOLEAN
 185 EFIAPI
 186 SerialPortPoll (
 187   VOID
 188   )
 189 {
 190   return FALSE;
 191 }
 192
 193 /**
 194   Sets the control bits on a serial device.
 195
 196   @param[in] Control            Sets the bits of Control that are settable.
 197
 198   @retval RETURN_SUCCESS        The new control bits were set on the serial device.
 199   @retval RETURN_UNSUPPORTED    The serial device does not support this operation.
 200   @retval RETURN_DEVICE_ERROR   The serial device is not functioning correctly.
 201
 202 **/
 203 RETURN_STATUS
 204 EFIAPI
 205 SerialPortSetControl (
 206   IN UINT32 Control
 207   )
 208 {
 209   return RETURN_UNSUPPORTED;
 210 }
 211
 212 /**
 213   Retrieve the status of the control bits on a serial device.
 214
 215   @param[out] Control           A pointer to return the current control signals from the serial device.
 216
 217   @retval RETURN_SUCCESS        The control bits were read from the serial device.
 218   @retval RETURN_UNSUPPORTED    The serial device does not support this operation.
 219   @retval RETURN_DEVICE_ERROR   The serial device is not functioning correctly.
 220
 221 **/
 222 RETURN_STATUS
 223 EFIAPI
 224 SerialPortGetControl (
 225   OUT UINT32 *Control
 226   )
 227 {
 228   return RETURN_UNSUPPORTED;
 229 }
 230
 231 /**
 232   Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
 233   data bits, and stop bits on a serial device.
 234
 235   @param BaudRate           The requested baud rate. A BaudRate value of 0 will use the
 236                             device's default interface speed.
 237                             On output, the value actually set.
 238   @param ReveiveFifoDepth   The requested depth of the FIFO on the receive side of the
 239                             serial interface. A ReceiveFifoDepth value of 0 will use
 240                             the device's default FIFO depth.
 241                             On output, the value actually set.
 242   @param Timeout            The requested time out for a single character in microseconds.
 243                             This timeout applies to both the transmit and receive side of the
 244                             interface. A Timeout value of 0 will use the device's default time
 245                             out value.
 246                             On output, the value actually set.
 247   @param Parity             The type of parity to use on this serial device. A Parity value of
 248                             DefaultParity will use the device's default parity value.
 249                             On output, the value actually set.
 250   @param DataBits           The number of data bits to use on the serial device. A DataBits
 251                             vaule of 0 will use the device's default data bit setting.
 252                             On output, the value actually set.
 253   @param StopBits           The number of stop bits to use on this serial device. A StopBits
 254                             value of DefaultStopBits will use the device's default number of
 255                             stop bits.
 256                             On output, the value actually set.
 257
 258   @retval RETURN_SUCCESS            The new attributes were set on the serial device.
 259   @retval RETURN_UNSUPPORTED        The serial device does not support this operation.
 260   @retval RETURN_INVALID_PARAMETER  One or more of the attributes has an unsupported value.
 261   @retval RETURN_DEVICE_ERROR       The serial device is not functioning correctly.
 262
 263 **/
 264 RETURN_STATUS
 265 EFIAPI
 266 SerialPortSetAttributes (
 267   IN OUT UINT64             *BaudRate,
 268   IN OUT UINT32             *ReceiveFifoDepth,
 269   IN OUT UINT32             *Timeout,
 270   IN OUT EFI_PARITY_TYPE    *Parity,
 271   IN OUT UINT8              *DataBits,
 272   IN OUT EFI_STOP_BITS_TYPE *StopBits
 273   )
 274 {
 275   return RETURN_UNSUPPORTED;
 276 }
 277