LXR linux/drivers/char/hvc

   1/*
   2 * udbg interface to hvc_console.c
   3 *
   4 * (C) Copyright David Gibson, IBM Corporation 2008.
   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
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19 */
  20
  21#include <linux/console.h>
  22#include <linux/delay.h>
  23#include <linux/err.h>
  24#include <linux/init.h>
  25#include <linux/moduleparam.h>
  26#include <linux/types.h>
  27#include <linux/irq.h>
  28
  29#include <asm/udbg.h>
  30
  31#include "hvc_console.h"
  32
  33struct hvc_struct *hvc_udbg_dev;
  34
  35static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
  36{
  37        int i;
  38
  39        for (i = 0; i < count; i++)
  40                udbg_putc(buf[i]);
  41
  42        return i;
  43}
  44
  45static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
  46{
  47        int i, c;
  48
  49        if (!udbg_getc_poll)
  50                return 0;
  51
  52        for (i = 0; i < count; i++) {
  53                if ((c = udbg_getc_poll()) == -1)
  54                        break;
  55                buf[i] = c;
  56        }
  57
  58        return i;
  59}
  60
  61static struct hv_ops hvc_udbg_ops = {
  62        .get_chars = hvc_udbg_get,
  63        .put_chars = hvc_udbg_put,
  64};
  65
  66static int __init hvc_udbg_init(void)
  67{
  68        struct hvc_struct *hp;
  69
  70        BUG_ON(hvc_udbg_dev);
  71
  72        hp = hvc_alloc(0, NO_IRQ, &hvc_udbg_ops, 16);
  73        if (IS_ERR(hp))
  74                return PTR_ERR(hp);
  75
  76        hvc_udbg_dev = hp;
  77
  78        return 0;
  79}
  80module_init(hvc_udbg_init);
  81
  82static void __exit hvc_udbg_exit(void)
  83{
  84        if (hvc_udbg_dev)
  85                hvc_remove(hvc_udbg_dev);
  86}
  87module_exit(hvc_udbg_exit);
  88
  89static int __init hvc_udbg_console_init(void)
  90{
  91        hvc_instantiate(0, 0, &hvc_udbg_ops);
  92        add_preferred_console("hvc", 0, NULL);
  93
  94        return 0;
  95}
  96console_initcall(hvc_udbg_console_init);
  97