1/*
2 * hvconsole.c
3 * Copyright (C) 2004 Hollis Blanchard, IBM Corporation
4 * Copyright (C) 2004 IBM Corporation
5 *
6 * Additional Author(s):
7 *  Ryan S. Arnold <rsa@us.ibm.com>
8 *
9 * LPAR console support.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24 */
25
26#include <linux/kernel.h>
27#include <linux/export.h>
28#include <linux/errno.h>
29#include <asm/hvcall.h>
30#include <asm/hvconsole.h>
31#include <asm/plpar_wrappers.h>
32
33/**
34 * hvc_get_chars - retrieve characters from firmware for denoted vterm adatper
35 * @vtermno: The vtermno or unit_address of the adapter from which to fetch the
36 *	data.
37 * @buf: The character buffer into which to put the character data fetched from
38 *	firmware.
39 * @count: not used?
40 */
41int hvc_get_chars(uint32_t vtermno, char *buf, int count)
42{
43	long ret;
44	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
45	unsigned long *lbuf = (unsigned long *)buf;
46
47	ret = plpar_hcall(H_GET_TERM_CHAR, retbuf, vtermno);
48	lbuf[0] = be64_to_cpu(retbuf[1]);
49	lbuf[1] = be64_to_cpu(retbuf[2]);
50
51	if (ret == H_SUCCESS)
52		return retbuf[0];
53
54	return 0;
55}
56
57EXPORT_SYMBOL(hvc_get_chars);
58
59
60/**
61 * hvc_put_chars: send characters to firmware for denoted vterm adapter
62 * @vtermno: The vtermno or unit_address of the adapter from which the data
63 *	originated.
64 * @buf: The character buffer that contains the character data to send to
65 *	firmware.
66 * @count: Send this number of characters.
67 */
68int hvc_put_chars(uint32_t vtermno, const char *buf, int count)
69{
70	unsigned long *lbuf = (unsigned long *) buf;
71	long ret;
72
73
74	/* hcall will ret H_PARAMETER if 'count' exceeds firmware max.*/
75	if (count > MAX_VIO_PUT_CHARS)
76		count = MAX_VIO_PUT_CHARS;
77
78	ret = plpar_hcall_norets(H_PUT_TERM_CHAR, vtermno, count,
79				 cpu_to_be64(lbuf[0]),
80				 cpu_to_be64(lbuf[1]));
81	if (ret == H_SUCCESS)
82		return count;
83	if (ret == H_BUSY)
84		return -EAGAIN;
85	return -EIO;
86}
87
88EXPORT_SYMBOL(hvc_put_chars);
89