LXR linux/arch/powerpc/platforms/celleb/udbg

   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 long inbuflen;
  44static long inbuf[2];   /* must be 2 longs */
  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, inbuf+0, inbuf+1);
  58                if (rc != 0)
  59                        inbuflen = 0;   /* otherwise inbuflen is garbage */
  60        }
  61        if (inbuflen <= 0 || inbuflen > 16) {
  62                /* Catch error case as well as other oddities (corruption) */
  63                inbuflen = 0;
  64                return -1;
  65        }
  66        ch = buf[0];
  67        for (i = 1; i < inbuflen; i++)  /* shuffle them down. */
  68                buf[i-1] = buf[i];
  69        inbuflen--;
  70        return ch;
  71}
  72
  73static int udbg_getc_beat(void)
  74{
  75        int ch;
  76        for (;;) {
  77                ch = udbg_getc_poll_beat();
  78                if (ch == -1) {
  79                        /* This shouldn't be needed...but... */
  80                        volatile unsigned long delay;
  81                        for (delay=0; delay < 2000000; delay++)
  82                                ;
  83                } else {
  84                        return ch;
  85                }
  86        }
  87}
  88
  89/* call this from early_init() for a working debug console on
  90 * vterm capable LPAR machines
  91 */
  92void __init udbg_init_debug_beat(void)
  93{
  94        udbg_putc = udbg_putc_beat;
  95        udbg_getc = udbg_getc_beat;
  96        udbg_getc_poll = udbg_getc_poll_beat;
  97}
  98