Add a slightly modified dev/ic/com.c that supports the Alchemy

Semiconductor Au1x00 series on-chip UARTs.  Will be merged with
the original com.c driver once a few issues are tidied up.  Main
differences from a standard 16550 UART are:
 - separate rxdata and txdata registers
 - single 16-bit register for the clock divisor
 - "enable uart" register

sys/arch/mips/alchemy/dev/aucomreg.h

@@ -0,0 +1,41 @@
+/* $NetBSD: aucomreg.h,v 1.1 2002/07/29 15:42:42 simonb Exp $ */
+
+/* copyright */
+
+#include <dev/ic/comreg.h>
+
+#undef com_data		/* XXX ... */
+#undef com_dlbl
+#undef com_dlbh
+#undef com_ier
+#undef com_iir
+#undef com_fifo
+#undef com_lctl
+#undef com_cfcr
+#undef com_mcr
+#undef com_lsr
+#undef com_msr
+#undef com_scratch
+
+#undef	COM_FREQ	/* relative to CPU clock speed on Au1X00 */
+
+/*
+ * Alchemy Semi Au1X00 UART registers
+ */
+
+#define	com_rxdata	0x00	/* receive data register (R) */
+#define	com_txdata	0x04	/* transmit data register (W) */
+#define	com_ier		0x08	/* interrupt enable (R/W) */
+#define	com_iir		0x0c	/* interrupt identification (R) */
+#define	com_fifo	0x10	/* FIFO control (R/W) */
+#define	com_lctl	0x14	/* line control register (R/W) */
+#define	com_cfcr	0x14	/* line control register (R/W) */
+#define	com_mcr		0x18	/* modem control register (R/W) */
+#define	com_lsr		0x1c	/* line status register (R) */
+#define	com_msr		0x20	/* modem status register (R) */
+#define	com_dlb		0x28	/* divisor latch (16bit) (R/W) */
+#define	com_modctl	0x100	/* module control register (R/W) */
+
+/* XXX ISA-specific. */
+#undef COM_NPORTS
+#define	COM_NPORTS	0x104

sys/arch/mips/alchemy/dev/aucomvar.h

@@ -0,0 +1,29 @@
+/* $NetBSD: aucomvar.h,v 1.1 2002/07/29 15:42:42 simonb Exp $ */
+
+/* copyright */
+
+/* Renamed externally visible functions */
+#define	com_attach_subr	aucom_attach_subr
+#define	comintr		aucomintr
+#define	comcnattach	aucomcnattach
+#define	com_is_console	aucom_is_console
+#define	com_kgdb_attach	aucom_kgdb_attach
+
+#define	comprobe1	xxx_aucomprobe1		/* unused */
+#define	com_detach	xxx_aucom_detach	/* unused */
+#define	com_activate	xxx_aucom_activate	/* unused */
+
+/* Renamed externally visible variables */
+#define	comcons		aucomcons
+#define	com_cd		aucom_cd
+#define	com_rbuf_size	aucom_rbuf_size
+#define	com_rbuf_hiwat	aucom_rbuf_hiwat
+#define	com_rbuf_lowat	aucom_rbuf_lowat
+#define	com_debug	aucom_debug
+
+#include <dev/ic/comvar.h>
+
+#undef COM_MPLOCK	/* just in case... */
+#undef COM_DEBUG
+#undef COM_HAYESP
+#undef COM16650