Annotation of sys/arch/armish/stand/boot/ns16550.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: ns16550.c,v 1.2 2006/07/29 15:01:49 kettenis Exp $ */
2: /* $NetBSD: ns16550.c,v 1.3 2005/12/24 20:07:03 perry Exp $ */
3:
4: /*
5: * Copyright (c) 2002 Wasabi Systems, Inc.
6: * All rights reserved.
7: *
8: * Written by Jason R. Thorpe for Wasabi Systems, Inc.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed for the NetBSD Project by
21: * Wasabi Systems, Inc.
22: * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23: * or promote products derived from this software without specific prior
24: * written permission.
25: *
26: * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
30: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36: * POSSIBILITY OF SUCH DAMAGE.
37: */
38:
39: /*
40: * This file provides console I/O routines for boards that use
41: * 16550-compatible UARTs.
42: */
43:
44: #include <sys/types.h>
45:
46: #include <dev/cons.h>
47: #include <dev/ic/comreg.h>
48:
49: #include "libsa.h"
50:
51: #define INB(x) *((volatile uint8_t *) (CONADDR + (x)))
52: #define OUTB(x, v) *((volatile uint8_t *) (CONADDR + (x))) = (v)
53:
54: #define ISSET(t,f) ((t) & (f))
55:
56: #ifndef NS16550_FREQ
57: #define NS16550_FREQ COM_FREQ
58: #endif
59:
60: static int
61: comspeed(int speed)
62: {
63: #define divrnd(n, q) (((n)*2/(q)+1)/2) /* divide and round off */
64:
65: int x, err;
66:
67: if (speed <= 0)
68: return (-1);
69: x = divrnd((NS16550_FREQ / 16), speed);
70: if (x <= 0)
71: return (-1);
72: err = divrnd((((quad_t)NS16550_FREQ) / 16) * 1000, speed * x) - 1000;
73: if (err < 0)
74: err = -err;
75: if (err > COM_TOLERANCE)
76: return (-1);
77: return (x);
78: #undef divrnd
79: }
80:
81: void
82: com_probe(struct consdev *cn)
83: {
84: cn->cn_pri = CN_NORMAL;
85: cn->cn_dev = makedev(12, 0);
86: }
87:
88: void
89: com_init(struct consdev *cn)
90: {
91: int rate;
92:
93: OUTB(com_cfcr, LCR_DLAB);
94: rate = comspeed(CONSPEED);
95: OUTB(com_dlbl, rate);
96: OUTB(com_dlbh, rate >> 8);
97: OUTB(com_cfcr, LCR_8BITS);
98: OUTB(com_mcr, MCR_DTR | MCR_RTS);
99: OUTB(com_fifo,
100: FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
101: OUTB(com_ier, 0);
102: }
103:
104: int
105: com_getc(dev_t dev)
106: {
107: uint8_t stat;
108:
109: if (dev & 0x80)
110: return ISSET(stat = INB(com_lsr), LSR_RXRDY);
111:
112: while (!ISSET(stat = INB(com_lsr), LSR_RXRDY))
113: /* spin */ ;
114: return (INB(com_data));
115: }
116:
117: void
118: com_putc(dev_t dev, int c)
119: {
120: uint8_t stat;
121: int timo;
122:
123: /* Wait for any pending transmission to finish. */
124: timo = 50000;
125: while (!ISSET(stat = INB(com_lsr), LSR_TXRDY) && --timo)
126: /* spin */ ;
127:
128: OUTB(com_data, c);
129:
130: /* Wait for this transmission to complete. */
131: timo = 1500000;
132: while (!ISSET(stat = INB(com_lsr), LSR_TXRDY) && --timo)
133: /* spin */ ;
134:
135: /* Clear any interrupts generated by this transmission. */
136: (void) INB(com_iir);
137: }
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