Subversion Repositories openrisc_2011-10-31

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#  $Id: README,v 1.2 2001-09-27 12:00:18 chris Exp $

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This driver was submitted by Katsutoshi Shibuya .

Configuration

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The application can choose this driver by using "CONSOLEX_DRIVER_TABLE_ENTRY"

in the driver table definition, in place of "CONSOLE_DRIVER_TABLE_ENTRY".

See consolex/cTest.c for an example and consolex/README for more information.

Programmatic Usage

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- You can open 9 devices; console tty00, tty01, tty02, tty03,

  rtty00, rtty01, rtty02, rtty03

  tty00, rtty00 and console correspond to port#1 of MVME162LX,

  tty01 and rtty01 correspond to port#2, and so on.

- tty0x are "cooked" devices. They support following flags on termios

  definition;

    ISTRIP, INLCR, IGNCR, ICRNL, IUCLC, OLCUC, ONLCR, OCRNL, ICANON, ECHO,

    CBAUD, B38400, B19200, B9600, CSIZE, CS8, CS7, PARENB, PARODD, CSTOPB,

- rtty0x are "raw" devices. They support following flags on termios

  definition;

    CBAUD, B38400, B19200, B9600, CSIZE, CS8, CS7, PARENB, PARODD, CSTOPB,

- The default parameter is;

    B38400, CS8, ICRNL, ONLCR, ICANON, ECHO

  (but all flags except B38400 and CS8 will be ignored on raw device.)

- All devices support O_NDELAY (non blocking read/write) mode operation.

  (Non-blocking cooked mode output is valid, but will not work fine.)

  (Non-blocking cooked mode input with ECHO flag may be blocked while sending

  echoed character.)

- All devices support hardware flow control by CTS/RTS.

  (There is no way to disable it. There are no supports for soft flow control.)

- The application can use tcgetattr or ioctl to obtain the parameters of the

  device into struct termios.

- The application can use tcsetattr or ioctl to set the parameters of the

  device within the struct temios. The action argument (2nd arg) of the

  tcsetattr must be TCSANOW.

- On opening the device, the driver activate DTR line.  On closing the device,

  the driver deactivate DTR line.

  If 2 or more device opening occures at the same time on the same port, only

  the first open procedure activates DTR line, and only the last close

  procedure deactivate it.

- There are no device locking mechanisms. Application can open same device

  several times.

  But 2 simultanious reading operation on the same port will cause unexpected

  result.

Porting Notes

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- This code can be used for any Zilog SCC based board.

  Change the time constant parameters and SCC register base addresses.

- This code is well separated into "device depended part" and "device

  independed part".

  They can use device independed part for any other board. The device

  independed part requires following functions;

  void SCCInitialize();

    Initialize hardware.

  rtems_boolean SCCGetOne(int port, char *ch);

    Get one character from port. If no character is in the receiver buffer,

    this function returns FALSE, otherwise TRUE.

  char SCCGetOneBlocked(int port);

    Get one character from port. If no character is in the receiver buffer,

    wait it passing the CPU to the other task.

  rtems_boolean SCCSendOne(int port, char ch);

    Send one character via port. If the transmitter is not ready, this function

    returns FALSE, otherwise TRUE.

  void SCCSendOneBlocked(int port, char ch);

    Send one character via port. Wait until the transmitter is ready, passing

    the CPU to the other task.

  unsigned32 SCCSetAttributes(int port, struct termios *tm);

    Set device attribute according to the information in the struct termios.

    c_cflags parameter (baud, parity, stopbits and code size) will be checked.

    On the successful completion, this function should return 0.

  unsigned32 SCCGetAttributes(int port, struct termios *tm);

    Get device attribute according into the struct termios.

    c_cflags parameter (baud, parity, stopbits and code size) will be set.

    On the successful completion, this function should return 0.

  void SCCSetDTR(port);

    Activate DTR line.

  void SCCResetDTR(port);

    Deactivate DTR line.

  void SCCSetRTS(port);

    Activate RTS line.

  void SCCResetRTS(port);

    Deactivate RTS line.

  int SCCGetCTS(port);

    Return non zero when CTS line is activated.

- If you don't want console port, undefine "CONSOLEPORT".

- This code does not use ESCC feature; i.e. does not read register #4/#5/#14