1// SPDX-License-Identifier: GPL-2.0
2/*
3 *    Copyright IBM Corp. 2017
4 */
5
6#include <linux/console.h>
7#include <linux/kernel.h>
8#include <linux/init.h>
9#include <asm/sclp.h>
10
11static void sclp_early_write(struct console *con, const char *s, unsigned int len)
12{
13	__sclp_early_printk(s, len);
14}
15
16static struct console sclp_early_console = {
17	.name  = "earlysclp",
18	.write = sclp_early_write,
19	.flags = CON_PRINTBUFFER | CON_BOOT,
20	.index = -1,
21};
22
23static int __init setup_early_printk(char *buf)
24{
25	if (early_console)
26		return 0;
27	/* Accept only "earlyprintk" and "earlyprintk=sclp" */
28	if (buf && !str_has_prefix(buf, "sclp"))
29		return 0;
30	if (!sclp.has_linemode && !sclp.has_vt220)
31		return 0;
32	early_console = &sclp_early_console;
33	register_console(early_console);
34	return 0;
35}
36early_param("earlyprintk", setup_early_printk);
37