tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * udbg function for Beat
3 *
4 * (C) Copyright 2006 TOSHIBA CORPORATION
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21#include <linux/kernel.h>
22#include <linux/console.h>
23
24#include <asm/machdep.h>
25#include <asm/prom.h>
26#include <asm/udbg.h>
27
28#include "beat.h"
29
30#define celleb_vtermno 0
31
32static void udbg_putc_beat(char c)
33{
34 unsigned long rc;
35
36 if (c == '\n')
37 udbg_putc_beat('\r');
38
39 rc = beat_put_term_char(celleb_vtermno, 1, (uint64_t)c << 56, 0);
40}
41
42/* Buffered chars getc */
43static u64 inbuflen;
44static u64 inbuf[2]; /* must be 2 u64s */
45
46static int udbg_getc_poll_beat(void)
47{
48 /* The interface is tricky because it may return up to 16 chars.
49 * We save them statically for future calls to udbg_getc().
50 */
51 char ch, *buf = (char *)inbuf;
52 int i;
53 long rc;
54 if (inbuflen == 0) {
55 /* get some more chars. */
56 inbuflen = 0;
57 rc = beat_get_term_char(celleb_vtermno, &inbuflen,
58 inbuf+0, inbuf+1);
59 if (rc != 0)
60 inbuflen = 0; /* otherwise inbuflen is garbage */
61 }
62 if (inbuflen <= 0 || inbuflen > 16) {
63 /* Catch error case as well as other oddities (corruption) */
64 inbuflen = 0;
65 return -1;
66 }
67 ch = buf[0];
68 for (i = 1; i < inbuflen; i++) /* shuffle them down. */
69 buf[i-1] = buf[i];
70 inbuflen--;
71 return ch;
72}
73
74static int udbg_getc_beat(void)
75{
76 int ch;
77 for (;;) {
78 ch = udbg_getc_poll_beat();
79 if (ch == -1) {
80 /* This shouldn't be needed...but... */
81 volatile unsigned long delay;
82 for (delay = 0; delay < 2000000; delay++)
83 ;
84 } else {
85 return ch;
86 }
87 }
88}
89
90/* call this from early_init() for a working debug console on
91 * vterm capable LPAR machines
92 */
93void __init udbg_init_debug_beat(void)
94{
95 udbg_putc = udbg_putc_beat;
96 udbg_getc = udbg_getc_beat;
97 udbg_getc_poll = udbg_getc_poll_beat;
98}