sys/src/9/pc/uartisa.c

   1 #include "u.h"
   2 #include "../port/lib.h"
   3 #include "mem.h"
   4 #include "dat.h"
   5 #include "fns.h"
   6 #include "io.h"
   7 #include "../port/error.h"
   8
   9 extern PhysUart i8250physuart;
  10 extern PhysUart isaphysuart;
  11 extern void* i8250alloc(int, int, int);
  12
  13 static Uart*
  14 uartisa(int ctlrno, ISAConf* isa)
  15 {
  16         int io;
  17         void *ctlr;
  18         Uart *uart;
  19         char buf[64];
  20
  21         uart = malloc(sizeof(Uart));
  22         if(uart == nil){
  23                 print("uartisa: no memory for Uart\n");
  24                 return nil;
  25         }
  26
  27         io = isa->port;
  28         snprint(buf, sizeof(buf), "%s%d", isaphysuart.name, ctlrno);
  29         if(ioalloc(io, 8, 0, buf) < 0){
  30                 print("uartisa: I/O 0x%uX in use\n", io);
  31                 free(uart);
  32                 return nil;
  33         }
  34
  35         ctlr = i8250alloc(io, isa->irq, BUSUNKNOWN);
  36         if(ctlr == nil){
  37                 iofree(io);
  38                 free(uart);
  39                 return nil;
  40         }
  41
  42         uart->regs = ctlr;
  43         snprint(buf, sizeof(buf), "COM%d", ctlrno+1);
  44         kstrdup(&uart->name, buf);
  45         uart->freq = isa->freq;
  46         uart->phys = &i8250physuart;
  47
  48         return uart;
  49 }
  50
  51 static Uart*
  52 uartisapnp(void)
  53 {
  54         int ctlrno;
  55         ISAConf isa;
  56         Uart *head, *tail, *uart;
  57
  58         /*
  59          * Look for up to 4 discrete UARTs on the ISA bus.
  60          * All suitable devices are configured to simply point
  61          * to the generic i8250 driver.
  62          */
  63         head = tail = nil;
  64         for(ctlrno = 2; ctlrno < 6; ctlrno++){
  65                 memset(&isa, 0, sizeof(isa));
  66                 if(!isaconfig("uart", ctlrno, &isa))
  67                         continue;
  68                 if(strcmp(isa.type, "isa") != 0)
  69                         continue;
  70                 if(isa.port == 0 || isa.irq == 0)
  71                         continue;
  72                 if(isa.freq == 0)
  73                         isa.freq = 1843200;
  74                 uart = uartisa(ctlrno, &isa);
  75                 if(uart == nil)
  76                         continue;
  77                 if(head != nil)
  78                         tail->next = uart;
  79                 else
  80                         head = uart;
  81                 tail = uart;
  82         }
  83
  84         return head;
  85 }
  86
  87 PhysUart isaphysuart = {
  88         .name           = "UartISA",
  89         .pnp            = uartisapnp,
  90         .enable         = nil,
  91         .disable        = nil,
  92         .kick           = nil,
  93         .dobreak        = nil,
  94         .baud           = nil,
  95         .bits           = nil,
  96         .stop           = nil,
  97         .parity         = nil,
  98         .modemctl       = nil,
  99         .rts            = nil,
 100         .dtr            = nil,
 101         .status         = nil,
 102         .fifo           = nil,
 103 };