/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2008 David Gibson, IBM Corporation
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2017 SiFive
 */

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

#include <asm/sbi.h>

#include "hvc_console.h"

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

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

        return i;
}

static ssize_t hvc_sbi_tty_get(uint32_t vtermno, u8 *buf, size_t count)
{
        size_t i;
        int c;

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

        return i;
}

static const struct hv_ops hvc_sbi_v01_ops = {
        .get_chars = hvc_sbi_tty_get,
        .put_chars = hvc_sbi_tty_put,
};

static ssize_t hvc_sbi_dbcn_tty_put(uint32_t vtermno, const u8 *buf, size_t count)
{
        return sbi_debug_console_write(buf, count);
}

static ssize_t hvc_sbi_dbcn_tty_get(uint32_t vtermno, u8 *buf, size_t count)
{
        return sbi_debug_console_read(buf, count);
}

static const struct hv_ops hvc_sbi_dbcn_ops = {
        .put_chars = hvc_sbi_dbcn_tty_put,
        .get_chars = hvc_sbi_dbcn_tty_get,
};

static int __init hvc_sbi_init(void)
{
        int err;

        if (sbi_debug_console_available) {
                err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_dbcn_ops, 256));
                if (err)
                        return err;
                hvc_instantiate(0, 0, &hvc_sbi_dbcn_ops);
        } else if (IS_ENABLED(CONFIG_RISCV_SBI_V01)) {
                err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_v01_ops, 256));
                if (err)
                        return err;
                hvc_instantiate(0, 0, &hvc_sbi_v01_ops);
        } else {
                return -ENODEV;
        }

        return 0;
}
device_initcall(hvc_sbi_init);