summaryrefslogtreecommitdiffstats
path: root/drivers/char/hvc_vio.c
blob: 94a542e20efb02eb07beb1266567e444b396219f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/*
 * vio driver interface to hvc_console.c
 *
 * This code was moved here to allow the remaing code to be reused as a
 * generic polling mode with semi-reliable transport driver core to the
 * console and tty subsystems.
 *
 *
 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
 * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
 * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
 * Copyright (C) 2004 IBM Corporation
 *
 * Additional Author(s):
 *  Ryan S. Arnold <rsa@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/types.h>
#include <linux/init.h>

#include <asm/hvconsole.h>
#include <asm/vio.h>
#include <asm/prom.h>
#include <asm/firmware.h>

#include "hvc_console.h"

char hvc_driver_name[] = "hvc_console";

static struct vio_device_id hvc_driver_table[] __devinitdata = {
	{"serial", "hvterm1"},
	{ "", "" }
};
MODULE_DEVICE_TABLE(vio, hvc_driver_table);

static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
{
	unsigned long got;
	int i;

	/*
	 * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
	 * so we play safe and avoid the situation where got > count which could
	 * overload the flip buffer.
	 */
	if (count < SIZE_VIO_GET_CHARS)
		return -EAGAIN;

	got = hvc_get_chars(vtermno, buf, count);

	/*
	 * Work around a HV bug where it gives us a null
	 * after every \r.  -- paulus
	 */
	for (i = 1; i < got; ++i) {
		if (buf[i] == 0 && buf[i-1] == '\r') {
			--got;
			if (i < got)
				memmove(&buf[i], &buf[i+1],
					got - i);
		}
	}
	return got;
}

static struct hv_ops hvc_get_put_ops = {
	.get_chars = filtered_get_chars,
	.put_chars = hvc_put_chars,
};

static int __devinit hvc_vio_probe(struct vio_dev *vdev,
				const struct vio_device_id *id)
{
	struct hvc_struct *hp;

	/* probed with invalid parameters. */
	if (!vdev || !id)
		return -EPERM;

	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
			MAX_VIO_PUT_CHARS);
	if (IS_ERR(hp))
		return PTR_ERR(hp);
	dev_set_drvdata(&vdev->dev, hp);

	return 0;
}

static int __devexit hvc_vio_remove(struct vio_dev *vdev)
{
	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);

	return hvc_remove(hp);
}

static struct vio_driver hvc_vio_driver = {
	.id_table	= hvc_driver_table,
	.probe		= hvc_vio_probe,
	.remove		= hvc_vio_remove,
	.driver		= {
		.name	= hvc_driver_name,
		.owner	= THIS_MODULE,
	}
};

static int hvc_vio_init(void)
{
	int rc;

	if (firmware_has_feature(FW_FEATURE_ISERIES))
		return -EIO;

	/* Register as a vio device to receive callbacks */
	rc = vio_register_driver(&hvc_vio_driver);

	return rc;
}
module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */

static void hvc_vio_exit(void)
{
	vio_unregister_driver(&hvc_vio_driver);
}
module_exit(hvc_vio_exit);

/* the device tree order defines our numbering */
static int hvc_find_vtys(void)
{
	struct device_node *vty;
	int num_found = 0;

	for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
			vty = of_find_node_by_name(vty, "vty")) {
		const uint32_t *vtermno;

		/* We have statically defined space for only a certain number
		 * of console adapters.
		 */
		if (num_found >= MAX_NR_HVC_CONSOLES)
			break;

		vtermno = of_get_property(vty, "reg", NULL);
		if (!vtermno)
			continue;

		if (device_is_compatible(vty, "hvterm1")) {
			hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
			++num_found;
		}
	}

	return num_found;
}
console_initcall(hvc_find_vtys);