sys/arch/evbarm/stand/board/ns16550.c

   1 /*      $NetBSD: ns16550.c,v 1.3 2005/12/24 20:07:03 perry Exp $        */
   2
   3 /*
   4  * Copyright (c) 2002 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /*
  39  * This file provides the cons_init() function and console I/O routines
  40  * for boards that use 16550-compatible UARTs.
  41  */
  42
  43 #include <sys/types.h>
  44 #include <dev/ic/comreg.h>
  45 #include <lib/libsa/stand.h>
  46
  47 #include "board.h"
  48
  49 #ifdef NS16550_AX4
  50 #define INB(x)          *((volatile uint8_t *) (CONADDR + ((x) * 4)))
  51 #define OUTB(x, v)      *((volatile uint8_t *) (CONADDR + ((x) * 4))) = (v)
  52 #else
  53 #define INB(x)          *((volatile uint8_t *) (CONADDR + (x)))
  54 #define OUTB(x, v)      *((volatile uint8_t *) (CONADDR + (x))) = (v)
  55 #endif
  56
  57 #define ISSET(t,f)      ((t) & (f))
  58
  59 #ifndef NS16550_FREQ
  60 #define NS16550_FREQ    COM_FREQ
  61 #endif
  62
  63 static int
  64 comspeed(int speed)
  65 {
  66 #define divrnd(n, q)    (((n)*2/(q)+1)/2)       /* divide and round off */
  67
  68         int x, err;
  69
  70         if (speed <= 0)
  71                 return (-1);
  72         x = divrnd((NS16550_FREQ / 16), speed);
  73         if (x <= 0)
  74                 return (-1);
  75         err = divrnd((((quad_t)NS16550_FREQ) / 16) * 1000, speed * x) - 1000;
  76         if (err < 0)
  77                 err = -err;
  78         if (err > COM_TOLERANCE)
  79                 return (-1);
  80         return (x);
  81 #undef divrnd
  82 }
  83
  84 void
  85 cons_init(void)
  86 {
  87         int rate;
  88
  89         OUTB(com_cfcr, LCR_DLAB);
  90         rate = comspeed(CONSPEED);
  91         OUTB(com_dlbl, rate);
  92         OUTB(com_dlbh, rate >> 8);
  93         OUTB(com_cfcr, LCR_8BITS);
  94         OUTB(com_mcr, MCR_DTR | MCR_RTS);
  95         OUTB(com_fifo,
  96             FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
  97         OUTB(com_ier, 0);
  98 }
  99
 100 int
 101 getchar(void)
 102 {
 103         uint8_t stat;
 104
 105         while (!ISSET(stat = INB(com_lsr), LSR_RXRDY))
 106                 /* spin */ ;
 107         return (INB(com_data));
 108 }
 109
 110 static void
 111 iputchar(int c)
 112 {
 113         uint8_t stat;
 114         int timo;
 115
 116         /* Wait for any pending transmission to finish. */
 117         timo = 50000;
 118         while (!ISSET(stat = INB(com_lsr), LSR_TXRDY) && --timo)
 119                 /* spin */ ;
 120
 121         OUTB(com_data, c);
 122
 123         /* Wait for this transmission to complete. */
 124         timo = 1500000;
 125         while (!ISSET(stat = INB(com_lsr), LSR_TXRDY) && --timo)
 126                 /* spin */ ;
 127
 128         /* Clear any interrupts generated by this transmission. */
 129         (void) INB(com_iir);
 130 }
 131
 132 void
 133 putchar(int c)
 134 {
 135
 136         if (c == '\n')
 137                 iputchar('\r');
 138         iputchar(c);
 139 }