xref: /linux/drivers/video/fbdev/core/fb_procfs.c (revision a940daa52167e9db8ecce82213813b735a9d9f23)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/proc_fs.h>
4 
5 #include "fb_internal.h"
6 
7 static struct proc_dir_entry *fb_proc_dir_entry;
8 
fb_seq_start(struct seq_file * m,loff_t * pos)9 static void *fb_seq_start(struct seq_file *m, loff_t *pos)
10 {
11 	mutex_lock(&registration_lock);
12 
13 	return (*pos < FB_MAX) ? pos : NULL;
14 }
15 
fb_seq_stop(struct seq_file * m,void * v)16 static void fb_seq_stop(struct seq_file *m, void *v)
17 {
18 	mutex_unlock(&registration_lock);
19 }
20 
fb_seq_next(struct seq_file * m,void * v,loff_t * pos)21 static void *fb_seq_next(struct seq_file *m, void *v, loff_t *pos)
22 {
23 	(*pos)++;
24 
25 	return (*pos < FB_MAX) ? pos : NULL;
26 }
27 
fb_seq_show(struct seq_file * m,void * v)28 static int fb_seq_show(struct seq_file *m, void *v)
29 {
30 	int i = *(loff_t *)v;
31 	struct fb_info *fi = registered_fb[i];
32 
33 	if (fi)
34 		seq_printf(m, "%d %s\n", fi->node, fi->fix.id);
35 
36 	return 0;
37 }
38 
39 static const struct seq_operations __maybe_unused fb_proc_seq_ops = {
40 	.start	= fb_seq_start,
41 	.stop	= fb_seq_stop,
42 	.next	= fb_seq_next,
43 	.show	= fb_seq_show,
44 };
45 
fb_init_procfs(void)46 int fb_init_procfs(void)
47 {
48 	struct proc_dir_entry *proc;
49 
50 	proc = proc_create_seq("fb", 0, NULL, &fb_proc_seq_ops);
51 	if (!proc)
52 		return -ENOMEM;
53 
54 	fb_proc_dir_entry = proc;
55 
56 	return 0;
57 }
58 
fb_cleanup_procfs(void)59 void fb_cleanup_procfs(void)
60 {
61 	proc_remove(fb_proc_dir_entry);
62 }
63