ref: cabbe0a84c7aae53316347185a5bdf8095bac9c8
dir: /sys/src/9/pc/uartisa.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, };