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      1 /*	$NetBSD: ns16550.c,v 1.5 2008/04/29 15:24:50 tsutsui Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2008 Izumi Tsutsui.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #ifdef CONS_SERIAL
     28 
     29 #include <lib/libsa/stand.h>
     30 #include <lib/libkern/libkern.h>
     31 
     32 #include <dev/ic/comreg.h>
     33 
     34 #include <machine/cpu.h>
     35 
     36 #include "boot.h"
     37 #include "ns16550.h"
     38 
     39 #define CSR_READ(base, reg)		(*(volatile uint8_t *)((base) + (reg)))
     40 #define CSR_WRITE(base, reg, val)					\
     41 	do {								\
     42 		*(volatile uint8_t *)((base) + (reg)) = (val);		\
     43 	} while (/* CONSTCOND */ 0)
     44 
     45 void *
     46 com_init(int addr, int speed)
     47 {
     48 	uint8_t *com_port;
     49 
     50 	com_port = (void *)MIPS_PHYS_TO_KSEG1(COM_BASE + addr);
     51 
     52 	CSR_WRITE(com_port, com_lctl, LCR_DLAB);
     53 	speed = comspeed(speed);
     54 	CSR_WRITE(com_port, com_dlbl, speed);
     55 	CSR_WRITE(com_port, com_dlbh, speed >> 8);
     56 
     57 	CSR_WRITE(com_port, com_lctl, LCR_PNONE | LCR_8BITS);
     58 	CSR_WRITE(com_port, com_mcr, MCR_RTS | MCR_DTR);
     59 	CSR_WRITE(com_port, com_fifo,
     60 	    FIFO_XMT_RST | FIFO_RCV_RST | FIFO_ENABLE);
     61 	CSR_WRITE(com_port, com_ier, 0);
     62 
     63 	return com_port;
     64 }
     65 
     66 void
     67 com_putc(void *dev, int c)
     68 {
     69 	volatile uint8_t *com_port = dev;
     70 
     71 	while ((CSR_READ(com_port, com_lsr) & LSR_TXRDY) == 0)
     72 		;
     73 
     74 	CSR_WRITE(com_port, com_data, c);
     75 }
     76 
     77 int
     78 com_getc(void *dev)
     79 {
     80 	volatile uint8_t *com_port = dev;
     81 
     82 	while ((CSR_READ(com_port, com_lsr) & LSR_RXRDY) == 0)
     83 		;
     84 
     85 	return CSR_READ(com_port, com_data);
     86 }
     87 
     88 int
     89 com_scankbd(void *dev)
     90 {
     91 	volatile uint8_t *com_port = dev;
     92 
     93 	if ((CSR_READ(com_port, com_lsr) & LSR_RXRDY) == 0)
     94 		return -1;
     95 
     96 	return CSR_READ(com_port, com_data);
     97 }
     98 #endif /* CONS_SERIAL */
     99