src/dev/uart8250.hh

   1 /*
   2  * Copyright (c) 2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Ali Saidi
  29  */
  30
  31 /** @file
  32  * Defines a 8250 UART
  33  */
  34
  35 #ifndef __DEV_UART8250_HH__
  36 #define __DEV_UART8250_HH__
  37
  38 #include "dev/io_device.hh"
  39 #include "dev/uart.hh"
  40 #include "params/Uart8250.hh"
  41
  42 /* UART8250 Interrupt ID Register
  43  *  bit 0    Interrupt Pending 0 = true, 1 = false
  44  *  bit 2:1  ID of highest priority interrupt
  45  *  bit 7:3  zeroes
  46  */
  47 const uint8_t IIR_NOPEND = 0x1;
  48
  49 // Interrupt IDs
  50 const uint8_t IIR_MODEM = 0x00; /* Modem Status (lowest priority) */
  51 const uint8_t IIR_TXID  = 0x02; /* Tx Data */
  52 const uint8_t IIR_RXID  = 0x04; /* Rx Data */
  53 const uint8_t IIR_LINE  = 0x06; /* Rx Line Status (highest priority)*/
  54
  55 const uint8_t UART_IER_RDI  = 0x01;
  56 const uint8_t UART_IER_THRI = 0x02;
  57 const uint8_t UART_IER_RLSI = 0x04;
  58
  59
  60 const uint8_t UART_LSR_TEMT = 0x40;
  61 const uint8_t UART_LSR_THRE = 0x20;
  62 const uint8_t UART_LSR_DR   = 0x01;
  63
  64 const uint8_t UART_MCR_LOOP = 0x10;
  65
  66
  67 class Terminal;
  68 class Platform;
  69
  70 class Uart8250 : public Uart
  71 {
  72   protected:
  73     uint8_t IER, DLAB, LCR, MCR;
  74     Tick lastTxInt;
  75
  76     class IntrEvent : public Event
  77     {
  78         protected:
  79             Uart8250 *uart;
  80             int intrBit;
  81         public:
  82             IntrEvent(Uart8250 *u, int bit);
  83             virtual void process();
  84             virtual const char *description() const;
  85             void scheduleIntr();
  86     };
  87
  88     IntrEvent txIntrEvent;
  89     IntrEvent rxIntrEvent;
  90
  91   public:
  92     typedef Uart8250Params Params;
  93     const Params *
  94     params() const
  95     {
  96         return dynamic_cast<const Params *>(_params);
  97     }
  98     Uart8250(const Params *p);
  99
 100     virtual Tick read(PacketPtr pkt);
 101     virtual Tick write(PacketPtr pkt);
 102     virtual AddrRangeList getAddrRanges() const;
 103
 104     /**
 105      * Inform the uart that there is data available.
 106      */
 107     virtual void dataAvailable();
 108
 109
 110     /**
 111      * Return if we have an interrupt pending
 112      * @return interrupt status
 113      */
 114     virtual bool intStatus() { return status ? true : false; }
 115
 116     virtual void serialize(std::ostream &os);
 117     virtual void unserialize(Checkpoint *cp, const std::string &section);
 118
 119 };
 120
 121 #endif // __TSUNAMI_UART_HH__