xref: /openbmc/linux/fs/proc/consoles.c (revision 12eb4683)
1 /*
2  * Copyright (c) 2010 Werner Fink, Jiri Slaby
3  *
4  * Licensed under GPLv2
5  */
6 
7 #include <linux/console.h>
8 #include <linux/kernel.h>
9 #include <linux/proc_fs.h>
10 #include <linux/seq_file.h>
11 #include <linux/tty_driver.h>
12 
13 /*
14  * This is handler for /proc/consoles
15  */
16 static int show_console_dev(struct seq_file *m, void *v)
17 {
18 	static const struct {
19 		short flag;
20 		char name;
21 	} con_flags[] = {
22 		{ CON_ENABLED,		'E' },
23 		{ CON_CONSDEV,		'C' },
24 		{ CON_BOOT,		'B' },
25 		{ CON_PRINTBUFFER,	'p' },
26 		{ CON_BRL,		'b' },
27 		{ CON_ANYTIME,		'a' },
28 	};
29 	char flags[ARRAY_SIZE(con_flags) + 1];
30 	struct console *con = v;
31 	unsigned int a;
32 	dev_t dev = 0;
33 
34 	if (con->device) {
35 		const struct tty_driver *driver;
36 		int index;
37 		driver = con->device(con, &index);
38 		if (driver) {
39 			dev = MKDEV(driver->major, driver->minor_start);
40 			dev += index;
41 		}
42 	}
43 
44 	for (a = 0; a < ARRAY_SIZE(con_flags); a++)
45 		flags[a] = (con->flags & con_flags[a].flag) ?
46 			con_flags[a].name : ' ';
47 	flags[a] = 0;
48 
49 	seq_setwidth(m, 21 - 1);
50 	seq_printf(m, "%s%d", con->name, con->index);
51 	seq_pad(m, ' ');
52 	seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',
53 			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
54 			flags);
55 	if (dev)
56 		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
57 
58 	seq_printf(m, "\n");
59 
60 	return 0;
61 }
62 
63 static void *c_start(struct seq_file *m, loff_t *pos)
64 {
65 	struct console *con;
66 	loff_t off = 0;
67 
68 	console_lock();
69 	for_each_console(con)
70 		if (off++ == *pos)
71 			break;
72 
73 	return con;
74 }
75 
76 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
77 {
78 	struct console *con = v;
79 	++*pos;
80 	return con->next;
81 }
82 
83 static void c_stop(struct seq_file *m, void *v)
84 {
85 	console_unlock();
86 }
87 
88 static const struct seq_operations consoles_op = {
89 	.start	= c_start,
90 	.next	= c_next,
91 	.stop	= c_stop,
92 	.show	= show_console_dev
93 };
94 
95 static int consoles_open(struct inode *inode, struct file *file)
96 {
97 	return seq_open(file, &consoles_op);
98 }
99 
100 static const struct file_operations proc_consoles_operations = {
101 	.open		= consoles_open,
102 	.read		= seq_read,
103 	.llseek		= seq_lseek,
104 	.release	= seq_release,
105 };
106 
107 static int __init proc_consoles_init(void)
108 {
109 	proc_create("consoles", 0, NULL, &proc_consoles_operations);
110 	return 0;
111 }
112 module_init(proc_consoles_init);
113