e4bfcfe8550ba91cc7515c3d3bd46bd7e39ba325
[linux-3.10.git] / arch / um / drivers / stdio_console.c
1 /* 
2  * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5
6 #include "linux/config.h"
7 #include "linux/posix_types.h"
8 #include "linux/tty.h"
9 #include "linux/tty_flip.h"
10 #include "linux/types.h"
11 #include "linux/major.h"
12 #include "linux/kdev_t.h"
13 #include "linux/console.h"
14 #include "linux/string.h"
15 #include "linux/sched.h"
16 #include "linux/list.h"
17 #include "linux/init.h"
18 #include "linux/interrupt.h"
19 #include "linux/slab.h"
20 #include "linux/hardirq.h"
21 #include "asm/current.h"
22 #include "asm/irq.h"
23 #include "stdio_console.h"
24 #include "line.h"
25 #include "chan_kern.h"
26 #include "user_util.h"
27 #include "kern_util.h"
28 #include "irq_user.h"
29 #include "mconsole_kern.h"
30 #include "init.h"
31
32 #define MAX_TTYS (16)
33
34 /* ----------------------------------------------------------------------------- */
35
36 /* Referenced only by tty_driver below - presumably it's locked correctly
37  * by the tty driver.
38  */
39
40 static struct tty_driver *console_driver;
41
42 void stdio_announce(char *dev_name, int dev)
43 {
44         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
45                dev_name);
46 }
47
48 static struct chan_opts opts = {
49         .announce       = stdio_announce,
50         .xterm_title    = "Virtual Console #%d",
51         .raw            = 1,
52         .tramp_stack    = 0,
53         .in_kernel      = 1,
54 };
55
56 static int con_config(char *str);
57 static int con_get_config(char *dev, char *str, int size, char **error_out);
58 static int con_remove(int n);
59
60 static struct line_driver driver = {
61         .name                   = "UML console",
62         .device_name            = "tty",
63         .major                  = TTY_MAJOR,
64         .minor_start            = 0,
65         .type                   = TTY_DRIVER_TYPE_CONSOLE,
66         .subtype                = SYSTEM_TYPE_CONSOLE,
67         .read_irq               = CONSOLE_IRQ,
68         .read_irq_name          = "console",
69         .write_irq              = CONSOLE_WRITE_IRQ,
70         .write_irq_name         = "console-write",
71         .symlink_from           = "ttys",
72         .symlink_to             = "vc",
73         .mc  = {
74                 .name           = "con",
75                 .config         = con_config,
76                 .get_config     = con_get_config,
77                 .id             = line_id,
78                 .remove         = con_remove,
79         },
80 };
81
82 static struct lines console_lines = LINES_INIT(MAX_TTYS);
83
84 /* The array is initialized by line_init, which is an initcall.  The 
85  * individual elements are protected by individual semaphores.
86  */
87 struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
88                               [ 1 ... MAX_TTYS - 1 ] =
89                               LINE_INIT(CONFIG_CON_CHAN, &driver) };
90
91 static int con_config(char *str)
92 {
93         return line_config(vts, ARRAY_SIZE(vts), str, &opts);
94 }
95
96 static int con_get_config(char *dev, char *str, int size, char **error_out)
97 {
98         return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out);
99 }
100
101 static int con_remove(int n)
102 {
103         return line_remove(vts, ARRAY_SIZE(vts), n);
104 }
105
106 static int con_open(struct tty_struct *tty, struct file *filp)
107 {
108         return line_open(vts, tty);
109 }
110
111 /* Set in an initcall, checked in an exitcall */
112 static int con_init_done = 0;
113
114 static const struct tty_operations console_ops = {
115         .open                   = con_open,
116         .close                  = line_close,
117         .write                  = line_write,
118         .put_char               = line_put_char,
119         .write_room             = line_write_room,
120         .chars_in_buffer        = line_chars_in_buffer,
121         .flush_buffer           = line_flush_buffer,
122         .flush_chars            = line_flush_chars,
123         .set_termios            = line_set_termios,
124         .ioctl                  = line_ioctl,
125         .throttle               = line_throttle,
126         .unthrottle             = line_unthrottle,
127 };
128
129 static void uml_console_write(struct console *console, const char *string,
130                               unsigned len)
131 {
132         struct line *line = &vts[console->index];
133         unsigned long flags;
134
135         spin_lock_irqsave(&line->lock, flags);
136         console_write_chan(&line->chan_list, string, len);
137         spin_unlock_irqrestore(&line->lock, flags);
138 }
139
140 static struct tty_driver *uml_console_device(struct console *c, int *index)
141 {
142         *index = c->index;
143         return console_driver;
144 }
145
146 static int uml_console_setup(struct console *co, char *options)
147 {
148         struct line *line = &vts[co->index];
149
150         return console_open_chan(line, co, &opts);
151 }
152
153 static struct console stdiocons = {
154         .name           = "tty",
155         .write          = uml_console_write,
156         .device         = uml_console_device,
157         .setup          = uml_console_setup,
158         .flags          = CON_PRINTBUFFER,
159         .index          = -1,
160         .data           = &vts,
161 };
162
163 int stdio_init(void)
164 {
165         char *new_title;
166
167         console_driver = line_register_devfs(&console_lines, &driver,
168                                              &console_ops, vts,
169                                              ARRAY_SIZE(vts));
170         if (console_driver == NULL)
171                 return -1;
172         printk(KERN_INFO "Initialized stdio console driver\n");
173
174         lines_init(vts, ARRAY_SIZE(vts), &opts);
175
176         new_title = add_xterm_umid(opts.xterm_title);
177         if(new_title != NULL)
178                 opts.xterm_title = new_title;
179
180         con_init_done = 1;
181         register_console(&stdiocons);
182         return 0;
183 }
184 late_initcall(stdio_init);
185
186 static void console_exit(void)
187 {
188         if (!con_init_done)
189                 return;
190         close_lines(vts, ARRAY_SIZE(vts));
191 }
192 __uml_exitcall(console_exit);
193
194 static int console_chan_setup(char *str)
195 {
196         return line_setup(vts, ARRAY_SIZE(vts), str);
197 }
198 __setup("con", console_chan_setup);
199 __channel_help(console_chan_setup, "con");