diff options
| author | phk <phk@FreeBSD.org> | 1997-05-18 20:53:52 +0000 |
|---|---|---|
| committer | phk <phk@FreeBSD.org> | 1997-05-18 20:53:52 +0000 |
| commit | 051d52fdad2544e1ad6604da5d137fe0d6bab7bd (patch) | |
| tree | 893201624114301f110af2a1351fb4391e222b4d /sys/isa | |
| parent | 02bc7ae6ab212db5f109ee89bbd2b724dd1e4732 (diff) | |
| download | FreeBSD-src-051d52fdad2544e1ad6604da5d137fe0d6bab7bd.zip FreeBSD-src-051d52fdad2544e1ad6604da5d137fe0d6bab7bd.tar.gz | |
Detect various supersets of 16550A based on fifo depth.
PR: i386/3523
Reviewed by: phk
Submitted by: vak@cronyx.ru
Diffstat (limited to 'sys/isa')
| -rw-r--r-- | sys/isa/sio.c | 43 |
1 files changed, 39 insertions, 4 deletions
diff --git a/sys/isa/sio.c b/sys/isa/sio.c index 54420e8..d31ded2 100644 --- a/sys/isa/sio.c +++ b/sys/isa/sio.c @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * from: @(#)com.c 7.5 (Berkeley) 5/16/91 - * $Id: sio.c,v 1.163 1997/04/18 18:28:09 bde Exp $ + * $Id: sio.c,v 1.164 1997/04/26 11:46:06 peter Exp $ */ #include "opt_comconsole.h" @@ -881,12 +881,47 @@ sioattach(isdp) printf(" 16550?"); break; case FIFO_RX_HIGH: - printf(" 16550A"); if (COM_NOFIFO(isdp)) { - printf(" fifo disabled"); + printf(" 16550A fifo disabled"); } else { + /* Detect the fifo size. */ + int i, n; + + /* Enable and reset the FIFO. */ + outb (iobase+com_fifo, FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST); + + /* Set the loopback mode, 57600 baud. */ + outb (iobase+com_cfcr, CFCR_DLAB); + outb (iobase+com_dlbh, 0); + outb (iobase+com_dlbl, 2); + outb (iobase+com_cfcr, CFCR_8BITS); + outb (iobase+com_mcr, MCR_LOOPBACK); + inb (iobase+com_lsr); + + /* Put data into transmit FIFO and wait until overrun. */ + for (i=n=0; i<20000; ++i) { + unsigned char lsr = inb (iobase+com_lsr); + if (lsr & LSR_OE) + break; + if (lsr & LSR_TXRDY) { + outb (iobase+com_data, 0x5A); + ++n; + } + } + outb (iobase+com_mcr, 0); + outb (iobase+com_fifo, 0); + com->hasfifo = TRUE; - com->tx_fifo_size = 16; + if (n > 40) { + com->tx_fifo_size = 64; + printf(" 16750"); + } else if (n > 24) { + com->tx_fifo_size = 32; + printf(" 16650"); + } else { + com->tx_fifo_size = 16; + printf(" 16550A"); + } #ifdef COM_ESP for (espp = likely_esp_ports; *espp != 0; espp++) if (espattach(isdp, com, *espp)) { |
