linux/arch/powerpc/platforms/cell/beat_udbg.c
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   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}
  99