1 files changed, 98 insertions, 0 deletions
diff --git a/os/pc/uartisa.c b/os/pc/uartisa.c
new file mode 100644
index 00000000..de4a8dcc
--- /dev/null
+++ b/os/pc/uartisa.c
@@ -0,0 +1,98 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+#include "../port/error.h"
+#include "../port/uart.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];
+
+	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);
+		return nil;
+	}
+
+	uart = malloc(sizeof(Uart));
+	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,
+};