plan9fox/sys/src/9/pc/uartisa.c
2013-05-20 17:32:48 +02:00

103 lines
1.8 KiB
C

#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/error.h"
extern PhysUart i8250physuart;
extern PhysUart isaphysuart;
extern void* i8250alloc(int, int, int);
static Uart*
uartisa(int ctlrno, ISAConf* isa)
{
int io;
void *ctlr;
Uart *uart;
char buf[64];
uart = malloc(sizeof(Uart));
if(uart == nil){
print("uartisa: no memory for Uart\n");
return nil;
}
io = isa->port;
snprint(buf, sizeof(buf), "%s%d", isaphysuart.name, ctlrno);
if(ioalloc(io, 8, 0, buf) < 0){
print("uartisa: I/O 0x%uX in use\n", io);
free(uart);
return nil;
}
ctlr = i8250alloc(io, isa->irq, BUSUNKNOWN);
if(ctlr == nil){
iofree(io);
free(uart);
return nil;
}
uart->regs = ctlr;
snprint(buf, sizeof(buf), "COM%d", ctlrno+1);
kstrdup(&uart->name, buf);
uart->freq = isa->freq;
uart->phys = &i8250physuart;
return uart;
}
static Uart*
uartisapnp(void)
{
int ctlrno;
ISAConf isa;
Uart *head, *tail, *uart;
/*
* Look for up to 4 discrete UARTs on the ISA bus.
* All suitable devices are configured to simply point
* to the generic i8250 driver.
*/
head = tail = nil;
for(ctlrno = 2; ctlrno < 6; ctlrno++){
memset(&isa, 0, sizeof(isa));
if(!isaconfig("uart", ctlrno, &isa))
continue;
if(strcmp(isa.type, "isa") != 0)
continue;
if(isa.port == 0 || isa.irq == 0)
continue;
if(isa.freq == 0)
isa.freq = 1843200;
uart = uartisa(ctlrno, &isa);
if(uart == nil)
continue;
if(head != nil)
tail->next = uart;
else
head = uart;
tail = uart;
}
return head;
}
PhysUart isaphysuart = {
.name = "UartISA",
.pnp = uartisapnp,
.enable = nil,
.disable = nil,
.kick = nil,
.dobreak = nil,
.baud = nil,
.bits = nil,
.stop = nil,
.parity = nil,
.modemctl = nil,
.rts = nil,
.dtr = nil,
.status = nil,
.fifo = nil,
};