xref: /openbmc/linux/fs/proc/consoles.c (revision 4cff79e9)
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_putc(m, '\n');
59 	return 0;
60 }
61 
62 static void *c_start(struct seq_file *m, loff_t *pos)
63 {
64 	struct console *con;
65 	loff_t off = 0;
66 
67 	console_lock();
68 	for_each_console(con)
69 		if (off++ == *pos)
70 			break;
71 
72 	return con;
73 }
74 
75 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
76 {
77 	struct console *con = v;
78 	++*pos;
79 	return con->next;
80 }
81 
82 static void c_stop(struct seq_file *m, void *v)
83 {
84 	console_unlock();
85 }
86 
87 static const struct seq_operations consoles_op = {
88 	.start	= c_start,
89 	.next	= c_next,
90 	.stop	= c_stop,
91 	.show	= show_console_dev
92 };
93 
94 static int consoles_open(struct inode *inode, struct file *file)
95 {
96 	return seq_open(file, &consoles_op);
97 }
98 
99 static const struct file_operations proc_consoles_operations = {
100 	.open		= consoles_open,
101 	.read		= seq_read,
102 	.llseek		= seq_lseek,
103 	.release	= seq_release,
104 };
105 
106 static int __init proc_consoles_init(void)
107 {
108 	proc_create("consoles", 0, NULL, &proc_consoles_operations);
109 	return 0;
110 }
111 fs_initcall(proc_consoles_init);
112