xref: /openbmc/linux/drivers/tty/hvc/hvc_vio.c (revision 4800cd83)
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 
42 static const char hvc_driver_name[] = "hvc_console";
43 
44 static struct vio_device_id hvc_driver_table[] __devinitdata = {
45 	{"serial", "hvterm1"},
46 	{ "", "" }
47 };
48 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
49 
50 static 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 	/*
66 	 * Work around a HV bug where it gives us a null
67 	 * after every \r.  -- paulus
68 	 */
69 	for (i = 1; i < got; ++i) {
70 		if (buf[i] == 0 && buf[i-1] == '\r') {
71 			--got;
72 			if (i < got)
73 				memmove(&buf[i], &buf[i+1],
74 					got - i);
75 		}
76 	}
77 	return got;
78 }
79 
80 static const struct hv_ops hvc_get_put_ops = {
81 	.get_chars = filtered_get_chars,
82 	.put_chars = hvc_put_chars,
83 	.notifier_add = notifier_add_irq,
84 	.notifier_del = notifier_del_irq,
85 	.notifier_hangup = notifier_hangup_irq,
86 };
87 
88 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
89 				const struct vio_device_id *id)
90 {
91 	struct hvc_struct *hp;
92 
93 	/* probed with invalid parameters. */
94 	if (!vdev || !id)
95 		return -EPERM;
96 
97 	hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
98 			MAX_VIO_PUT_CHARS);
99 	if (IS_ERR(hp))
100 		return PTR_ERR(hp);
101 	dev_set_drvdata(&vdev->dev, hp);
102 
103 	return 0;
104 }
105 
106 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
107 {
108 	struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
109 
110 	return hvc_remove(hp);
111 }
112 
113 static struct vio_driver hvc_vio_driver = {
114 	.id_table	= hvc_driver_table,
115 	.probe		= hvc_vio_probe,
116 	.remove		= __devexit_p(hvc_vio_remove),
117 	.driver		= {
118 		.name	= hvc_driver_name,
119 		.owner	= THIS_MODULE,
120 	}
121 };
122 
123 static int __init hvc_vio_init(void)
124 {
125 	int rc;
126 
127 	if (firmware_has_feature(FW_FEATURE_ISERIES))
128 		return -EIO;
129 
130 	/* Register as a vio device to receive callbacks */
131 	rc = vio_register_driver(&hvc_vio_driver);
132 
133 	return rc;
134 }
135 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
136 
137 static void __exit hvc_vio_exit(void)
138 {
139 	vio_unregister_driver(&hvc_vio_driver);
140 }
141 module_exit(hvc_vio_exit);
142 
143 /* the device tree order defines our numbering */
144 static int hvc_find_vtys(void)
145 {
146 	struct device_node *vty;
147 	int num_found = 0;
148 
149 	for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
150 			vty = of_find_node_by_name(vty, "vty")) {
151 		const uint32_t *vtermno;
152 
153 		/* We have statically defined space for only a certain number
154 		 * of console adapters.
155 		 */
156 		if (num_found >= MAX_NR_HVC_CONSOLES) {
157 			of_node_put(vty);
158 			break;
159 		}
160 
161 		vtermno = of_get_property(vty, "reg", NULL);
162 		if (!vtermno)
163 			continue;
164 
165 		if (of_device_is_compatible(vty, "hvterm1")) {
166 			hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
167 			++num_found;
168 		}
169 	}
170 
171 	return num_found;
172 }
173 console_initcall(hvc_find_vtys);
174