mg5uart.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 *  This file contains the termios TTY driver for the UART found
 *  on the Synova Mongoose-V.
 *
 *  COPYRIGHT (c) 1989-2001.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.com/license/LICENSE.
 *
 *  $Id: mg5uart.c,v 1.4.6.1 2003/09/04 18:45:49 joel Exp $
 */

#include <rtems.h>
#include <rtems/libio.h>
#include <stdlib.h>

#include <libchip/serial.h>
#include <libchip/mg5uart.h>
#include <libchip/sersupp.h>
#include <libcpu/mongoose-v.h>

extern void set_vector( rtems_isr_entry, rtems_vector_number, int );

/*
 *  Indices of registers
 */

/*
 *  Per chip context control
 */

typedef struct _mg5uart_context
{
  int            mate;
} mg5uart_context;

/*
 *  Define MG5UART_STATIC to nothing while debugging so the entry points
 *  will show up in the symbol table.
 */

#define MG5UART_STATIC

/* #define MG5UART_STATIC static */



#define MG5UART_SETREG( _base, _register, _value ) \
        MONGOOSEV_WRITE_REGISTER( _base, _register, _value )

#define MG5UART_GETREG( _base, _register ) \
        MONGOOSEV_READ_REGISTER( _base, _register )


/*
 *  Console Device Driver Support Functions
 */

MG5UART_STATIC int mg5uart_baud_rate(
  int           minor,
  int           baud,
  unsigned int *code
);

MG5UART_STATIC void mg5uart_enable_interrupts(
  int minor,
  int mask
);

/*
 *  mg5uart_set_attributes
 *
 *  This function sets the UART channel to reflect the requested termios
 *  port settings.
 */

MG5UART_STATIC int mg5uart_set_attributes(
  int minor,
  const struct termios *t
)
{
  unsigned32             pMG5UART_port;
  unsigned32             pMG5UART;
  unsigned32             cmd, cmdSave;
  unsigned32             baudcmd;
  unsigned32             shift;
  rtems_interrupt_level  Irql;

  pMG5UART      = Console_Port_Tbl[minor].ulCtrlPort1;
  pMG5UART_port = Console_Port_Tbl[minor].ulCtrlPort2;

  /*
   *  Set the baud rate
   */

  if (mg5uart_baud_rate( minor, t->c_cflag, &baudcmd ) == -1)
    return -1;

  /*
   *  Base settings
   */

  /*
   *  Base settings
   */

  cmd = MONGOOSEV_UART_CMD_RX_ENABLE | MONGOOSEV_UART_CMD_TX_ENABLE;

  /*
   *  Parity
   */

  if (t->c_cflag & PARENB) {
    cmd |= MONGOOSEV_UART_CMD_PARITY_ENABLE;
    if (t->c_cflag & PARODD)
      cmd |= MONGOOSEV_UART_CMD_PARITY_ODD;
    else
      cmd |= MONGOOSEV_UART_CMD_PARITY_EVEN;
  } else {
    cmd |= MONGOOSEV_UART_CMD_PARITY_DISABLE;
  }

  /*
   *  Character Size
   */

  if (t->c_cflag & CSIZE) {
    switch (t->c_cflag & CSIZE) {
      case CS5:
      case CS6:
      case CS7:
        return -1;
        break;
      case CS8:
        /* Mongoose-V only supports CS8 */
        break;

    }
  } /* else default to CS8 */

  /*
   *  Stop Bits
   */

#if 0
  if (t->c_cflag & CSTOPB) {
    /* 2 stop bits not supported by Mongoose-V uart */
    return -1;
  }
#endif

  /*
   *  XXX what about CTS/RTS
   */

  /* XXX */

  /*
   *  Now write the registers
   */

  if ( Console_Port_Tbl[minor].ulDataPort == MG5UART_UART0 )
    shift = MONGOOSEV_UART0_CMD_SHIFT;
  else
    shift = MONGOOSEV_UART1_CMD_SHIFT;



  rtems_interrupt_disable(Irql);

  cmdSave = MG5UART_GETREG( pMG5UART, MG5UART_COMMAND_REGISTER );

  MG5UART_SETREG( pMG5UART, 
		  MG5UART_COMMAND_REGISTER, 
		  (cmdSave & ~(MONGOOSEV_UART_ALL_STATUS_BITS << shift)) | (cmd << shift) );

  MG5UART_SETREG( pMG5UART_port, MG5UART_BAUD_RATE, baudcmd );

  rtems_interrupt_enable(Irql);
  return 0;
}

/*
 *  mg5uart_initialize_context
 *
 *  This function sets the default values of the per port context structure.
 */

MG5UART_STATIC void mg5uart_initialize_context(
  int               minor,
  mg5uart_context  *pmg5uartContext
)
{
  int          port;
  unsigned int pMG5UART;
  unsigned int pMG5UART_port;

  pMG5UART      = Console_Port_Tbl[minor].ulCtrlPort1;
  pMG5UART_port = Console_Port_Tbl[minor].ulCtrlPort2;

  pmg5uartContext->mate = -1;

  for (port=0 ; port<Console_Port_Count ; port++ ) {
    if ( Console_Port_Tbl[port].ulCtrlPort1 == pMG5UART &&
         Console_Port_Tbl[port].ulCtrlPort2 != pMG5UART_port ) {
      pmg5uartContext->mate = port;
      break;
    }
  }

}

/*
 *  mg5uart_init
 *
 *  This function initializes the DUART to a quiecsent state.
 */

MG5UART_STATIC void mg5uart_init(int minor)
{
  unsigned32            pMG5UART_port;
  unsigned32            pMG5UART;
  unsigned32		cmdSave;
  unsigned32		shift;

  mg5uart_context        *pmg5uartContext;

  pmg5uartContext = (mg5uart_context *) malloc(sizeof(mg5uart_context));

  Console_Port_Data[minor].pDeviceContext = (void *)pmg5uartContext;

  mg5uart_initialize_context( minor, pmg5uartContext );

  pMG5UART      = Console_Port_Tbl[minor].ulCtrlPort1;
  pMG5UART_port = Console_Port_Tbl[minor].ulCtrlPort2;

  if ( Console_Port_Tbl[minor].ulDataPort == MG5UART_UART0 )
     shift = MONGOOSEV_UART0_CMD_SHIFT;
  else
     shift = MONGOOSEV_UART1_CMD_SHIFT;

  /*
   *  Disable the uart and leave this port disabled.
   */

  cmdSave = MG5UART_GETREG(pMG5UART, MG5UART_COMMAND_REGISTER) & ~(MONGOOSEV_UART_ALL_STATUS_BITS << shift);

  MG5UART_SETREG( pMG5UART, MG5UART_COMMAND_REGISTER, cmdSave );

  /*
   *  Disable interrupts on RX and TX for this port
   */
  mg5uart_enable_interrupts( minor, MG5UART_DISABLE_ALL );
}

/*
 *  mg5uart_open
 *
 *  This function opens a port for communication.
 *
 *  Default state is 9600 baud, 8 bits, No parity, and 1 stop bit.
 */

MG5UART_STATIC int mg5uart_open(
  int      major,
  int      minor,
  void    *arg
)
{
  unsigned32    pMG5UART;
  unsigned32    pMG5UART_port;
  unsigned32	vector;
  unsigned32    cmd, cmdSave;
  unsigned32    baudcmd;
  unsigned32    shift;

  rtems_interrupt_level  Irql;

  pMG5UART      = Console_Port_Tbl[minor].ulCtrlPort1;
  pMG5UART_port = Console_Port_Tbl[minor].ulCtrlPort2;
  vector        = Console_Port_Tbl[minor].ulIntVector;

  if ( Console_Port_Tbl[minor].ulDataPort == MG5UART_UART0 )
    shift = MONGOOSEV_UART0_CMD_SHIFT;
  else
    shift = MONGOOSEV_UART1_CMD_SHIFT;


  /* XXX default baud rate could be from configuration table */

  (void) mg5uart_baud_rate( minor, B19200, &baudcmd );

  /*
   *  Set the DUART channel to a default useable state
   *  B19200, 8Nx since there is no stop bit control.
   */

  cmd = MONGOOSEV_UART_CMD_TX_ENABLE | MONGOOSEV_UART_CMD_RX_ENABLE;

  rtems_interrupt_disable(Irql);

  cmdSave = MG5UART_GETREG( pMG5UART, MG5UART_COMMAND_REGISTER );

  MG5UART_SETREG( pMG5UART_port, MG5UART_BAUD_RATE, baudcmd );

  MG5UART_SETREG( pMG5UART, 
		  MG5UART_COMMAND_REGISTER, 
		  cmd = (cmdSave & ~(MONGOOSEV_UART_ALL_STATUS_BITS << shift)) | (cmd << shift) );

  rtems_interrupt_enable(Irql);

  return RTEMS_SUCCESSFUL;
}

/*
 *  mg5uart_close
 *
 *  This function shuts down the requested port.
 */

MG5UART_STATIC int mg5uart_close(
  int      major,
  int      minor,
  void    *arg
)
{
  unsigned32    pMG5UART;
  unsigned32    pMG5UART_port;
  unsigned32	cmd, cmdSave;
  unsigned32    shift;
  rtems_interrupt_level  Irql;

  pMG5UART      = Console_Port_Tbl[minor].ulCtrlPort1;
  pMG5UART_port = Console_Port_Tbl[minor].ulCtrlPort2;

  /*
   *  Disable interrupts from this channel and then disable it totally.
   */

  /* XXX interrupts */

  cmd = MONGOOSEV_UART_CMD_TX_DISABLE | MONGOOSEV_UART_CMD_RX_DISABLE;

  if ( Console_Port_Tbl[minor].ulDataPort == MG5UART_UART0 )
    shift = MONGOOSEV_UART0_CMD_SHIFT;
  else
    shift = MONGOOSEV_UART1_CMD_SHIFT;


  rtems_interrupt_disable(Irql);
  cmdSave = MG5UART_GETREG( pMG5UART, MG5UART_COMMAND_REGISTER );

  MG5UART_SETREG( pMG5UART, 
		  MG5UART_COMMAND_REGISTER,  
		  (cmdSave & ~(MONGOOSEV_UART_ALL_STATUS_BITS << shift)) | (cmd << shift) );
  rtems_interrupt_enable(Irql);

  return(RTEMS_SUCCESSFUL);
}




/*
 *  mg5uart_write_polled
 *
 *  This routine polls out the requested character.
 */

MG5UART_STATIC void mg5uart_write_polled(
  int   minor,
  char  c
)
{
  unsigned32              pMG5UART;
  unsigned32              pMG5UART_port;
  unsigned32              status;
  int                     shift;
  int                     timeout;

  pMG5UART      = Console_Port_Tbl[minor].ulCtrlPort1;
  pMG5UART_port = Console_Port_Tbl[minor].ulCtrlPort2;

  if ( Console_Port_Tbl[minor].ulDataPort == MG5UART_UART0 )
    shift = MONGOOSEV_UART0_IRQ_SHIFT;
  else
    shift = MONGOOSEV_UART1_IRQ_SHIFT;

  /*
   * wait for transmitter holding register to be empty
   */
  timeout = 2000;

  while( --timeout ) 
  {
    status = MG5UART_GETREG(pMG5UART, MG5UART_STATUS_REGISTER) >> shift;

    /*
    if ( (status & (MONGOOSEV_UART_TX_READY | MONGOOSEV_UART_TX_EMPTY)) ==
            (MONGOOSEV_UART_TX_READY | MONGOOSEV_UART_TX_EMPTY) )
      break;
    */

    if( (status & (MONGOOSEV_UART_TX_READY | MONGOOSEV_UART_TX_EMPTY)) )
       break;

    /*
     * Yield while we wait
     */

#if 0
     if(_System_state_Is_up(_System_state_Get())) 
     {
       rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
     }
#endif
  }

  /*
   * transmit character
   */

  MG5UART_SETREG(pMG5UART_port, MG5UART_TX_BUFFER, c);
}




/*
 *  mg5uart_isr_XXX
 *
 *  This is the single interrupt entry point which parcels interrupts
 *  out to the handlers for specific sources and makes sure that the
 *  shared handler gets the right arguments.
 *
 *  NOTE: Yes .. this is ugly but it provides 5 interrupt source