hvc_udbg.c

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/*
 * udbg interface to hvc_console.c
 *
 * (C) Copyright David Gibson, IBM Corporation 2008.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/console.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/irq.h>

#include <asm/udbg.h>

#include "hvc_console.h"

struct hvc_struct *hvc_udbg_dev;

static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
{
    int i;

    for (i = 0; i < count && udbg_putc; i++)
        udbg_putc(buf[i]);

    return i;
}

static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
{
    int i, c;

    if (!udbg_getc_poll)
        return 0;

    for (i = 0; i < count; i++) {
        if ((c = udbg_getc_poll()) == -1)
            break;
        buf[i] = c;
    }

    return i;
}

static const struct hv_ops hvc_udbg_ops = {
    .get_chars = hvc_udbg_get,
    .put_chars = hvc_udbg_put,
};

static int __init hvc_udbg_init(void)
{
    struct hvc_struct *hp;

    if (!udbg_putc)
        return -ENODEV;

    BUG_ON(hvc_udbg_dev);

    hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
    if (IS_ERR(hp))
        return PTR_ERR(hp);

    hvc_udbg_dev = hp;

    return 0;
}
module_init(hvc_udbg_init);

static void __exit hvc_udbg_exit(void)
{
    if (hvc_udbg_dev)
        hvc_remove(hvc_udbg_dev);
}
module_exit(hvc_udbg_exit);

static int __init hvc_udbg_console_init(void)
{
    if (!udbg_putc)
        return -ENODEV;

    hvc_instantiate(0, 0, &hvc_udbg_ops);
    add_preferred_console("hvc", 0, NULL);

    return 0;
}
console_initcall(hvc_udbg_console_init);