1/*
2 * vio driver interface to hvc_console.c
3 *
4 * This code was moved here to allow the remaing code to be reused as a
5 * generic polling mode with semi-reliable transport driver core to the
6 * console and tty subsystems.
7 *
8 *
9 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
10 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
11 * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
12 * Copyright (C) 2004 IBM Corporation
13 *
14 * Additional Author(s):
15 *  Ryan S. Arnold <rsa@us.ibm.com>
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25 * GNU General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
30 */
31
32#include <linux/types.h>
33#include <linux/init.h>
34
35#include <asm/hvconsole.h>
36#include <asm/vio.h>
37#include <asm/prom.h>
38#include <asm/firmware.h>
39
40#include "hvc_console.h"
41
42char hvc_driver_name[] = "hvc_console";
43
44static struct vio_device_id hvc_driver_table[] __devinitdata = {
45	{"serial", "hvterm1"},
46	{ "", "" }
47};
48MODULE_DEVICE_TABLE(vio, hvc_driver_table);
49
50static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
51{
52	unsigned long got;
53	int i;
54
55	/*
56	 * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
57	 * so we play safe and avoid the situation where got > count which could
58	 * overload the flip buffer.
59	 */
60	if (count < SIZE_VIO_GET_CHARS)
61		return -EAGAIN;
62
63	got = hvc_get_chars(vtermno, buf, count);
64
65	for (i = 1; i < got; ++i) {
66		if (buf[i] == 0 && buf[i-1] == '\r') {
67			--got;
68			if (i < got)
69				memmove(&buf[i], &buf[i+1],
70					got - i);
71		}
72	}
73	return got;
74}
75
76static struct hv_ops hvc_get_put_ops = {
77	.get_chars = filtered_get_chars,
78	.put_chars = hvc_put_chars,
79};
80
81static int __devinit hvc_vio_probe(struct vio_dev *vdev,
82				const struct vio_device_id *id)
83{
84	struct hvc_struct *hp;
85
86	/* probed with invalid parameters. */
87	if (!vdev || !id)
88		return -EPERM;
89
90	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
91			MAX_VIO_PUT_CHARS);
92	if (IS_ERR(hp))
93		return PTR_ERR(hp);
94	dev_set_drvdata(&vdev->dev, hp);
95
96	return 0;
97}
98
99static int __devexit hvc_vio_remove(struct vio_dev *vdev)
100{
101	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
102
103	return hvc_remove(hp);
104}
105
106static struct vio_driver hvc_vio_driver = {
107	.id_table	= hvc_driver_table,
108	.probe		= hvc_vio_probe,
109	.remove		= hvc_vio_remove,
110	.driver		= {
111		.name	= hvc_driver_name,
112		.owner	= THIS_MODULE,
113	}
114};
115
116static int hvc_vio_init(void)
117{
118	int rc;
119
120	if (firmware_has_feature(FW_FEATURE_ISERIES))
121		return -EIO;
122
123	/* Register as a vio device to receive callbacks */
124	rc = vio_register_driver(&hvc_vio_driver);
125
126	return rc;
127}
128module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
129
130static void hvc_vio_exit(void)
131{
132	vio_unregister_driver(&hvc_vio_driver);
133}
134module_exit(hvc_vio_exit);
135
136/* the device tree order defines our numbering */
137static int hvc_find_vtys(void)
138{
139	struct device_node *vty;
140	int num_found = 0;
141
142	for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
143			vty = of_find_node_by_name(vty, "vty")) {
144		const uint32_t *vtermno;
145
146		/* We have statically defined space for only a certain number
147		 * of console adapters.
148		 */
149		if (num_found >= MAX_NR_HVC_CONSOLES)
150			break;
151
152		vtermno = of_get_property(vty, "reg", NULL);
153		if (!vtermno)
154			continue;
155
156		if (of_device_is_compatible(vty, "hvterm1")) {
157			hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
158			++num_found;
159		}
160	}
161
162	return num_found;
163}
164console_initcall(hvc_find_vtys);
165