// SPDX-License-Identifier: GPL-2.0
/*
 * console.c: Routines that deal with sending and receiving IO
 *            to/from the current console device using the PROM.
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1998 Pete Zaitcev <zaitcev@yahoo.com>
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <linux/string.h>

extern void restore_current(void);

/* Non blocking put character to console device, returns -1 if
 * unsuccessful.
 */
static int prom_nbputchar(const char *buf)
{
        unsigned long flags;
        int i = -1;

        spin_lock_irqsave(&prom_lock, flags);
        switch(prom_vers) {
        case PROM_V0:
                if ((*(romvec->pv_nbputchar))(*buf))
                        i = 1;
                break;
        case PROM_V2:
        case PROM_V3:
                if ((*(romvec->pv_v2devops).v2_dev_write)(*romvec->pv_v2bootargs.fd_stdout,
                                                          buf, 0x1) == 1)
                        i = 1;
                break;
        default:
                break;
        }
        restore_current();
        spin_unlock_irqrestore(&prom_lock, flags);
        return i; /* Ugh, we could spin forever on unsupported proms ;( */
}

void prom_console_write_buf(const char *buf, int len)
{
        while (len) {
                int n = prom_nbputchar(buf);
                if (n < 0)
                        continue;
                len--;
                buf++;
        }
}