// SPDX-License-Identifier: GPL-2.0+
/*
 * udbg interface to hvc_console.c
 *
 * (C) Copyright David Gibson, IBM Corporation 2008.
 */

#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"

static struct hvc_struct *hvc_udbg_dev;

static ssize_t hvc_udbg_put(uint32_t vtermno, const u8 *buf, size_t count)
{
        size_t i;

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

        return i;
}

static ssize_t hvc_udbg_get(uint32_t vtermno, u8 *buf, size_t count)
{
        size_t i;
        int 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;
}
device_initcall(hvc_udbg_init);

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);