| MAGMA(4) | Device Drivers Manual (sparc) | MAGMA(4) | 
magma —
magma* at sbus? slot ? offset ?
mtty* at magma?
mbpp* at magma?
magma driver provides an interface to Magma LC2+1Sp,
  2+1Sp, 4+1Sp, 8+2Sp, 4Sp, 8Sp, 12Sp, 16Sp, 1P and 2P boards. These boards are
  based around the Cirrus Logic CD1400 serial/parallel communications engine and
  the Cirrus Logic CD1190 parallel communications engine.
The device minor numbers for this driver are encoded as follows:
    +---+---+---+---+---+---+---+---+
    | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
    +---+---+---+---+---+---+---+---+
      |   |   |   |   |   |   |   |
      |   |   |   |   +---+---+---+---> port number
      |   |   |   |
      |   |   |   +-------------------> dial-out (on tty ports)
      |   |   |
      |   |   +-----------------------> unused
      |   |
      +---+---------------------------> card number
Up to four cards are supported in the system.
All tty ports have full automatic hardware (RTS/CTS) flow control available and a 12 byte FIFO on the chip in each direction so errors should be minimal.
If need be you can make the ring buffer bigger by changing the
        MAGMA_RBUF_SIZE #define to something bigger, but
        it should be a multiple of two.
Reducing the value of either the
        MTTY_RX_FIFO_THRESHOLD or
        MTTY_RX_DTR_THRESHOLD #define's to something
        smaller may help slow machines avoid this problem.
“bpp” input.
Dial-out (cua) devices are not yet supported.
“mdmbuf” is unsupported (see tty(4) and termios(4)).
Automatic XON/XOFF handshaking could be implemented fairly easily.
It would be good if the tty port waited for the FIFO to empty before allowing a close, so that I could turn off the channel interrupts at that time. It can be done.
| April 21, 1998 | NetBSD 10.1 |