xref: /openbmc/linux/arch/um/drivers/fd.c (revision 87c2ce3b)
1 /*
2  * Copyright (C) 2001 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <unistd.h>
9 #include <termios.h>
10 #include <errno.h>
11 #include "user.h"
12 #include "user_util.h"
13 #include "chan_user.h"
14 
15 struct fd_chan {
16 	int fd;
17 	int raw;
18 	struct termios tt;
19 	char str[sizeof("1234567890\0")];
20 };
21 
22 static void *fd_init(char *str, int device, struct chan_opts *opts)
23 {
24 	struct fd_chan *data;
25 	char *end;
26 	int n;
27 
28 	if(*str != ':'){
29 		printk("fd_init : channel type 'fd' must specify a file "
30 		       "descriptor\n");
31 		return(NULL);
32 	}
33 	str++;
34 	n = strtoul(str, &end, 0);
35 	if((*end != '\0') || (end == str)){
36 		printk("fd_init : couldn't parse file descriptor '%s'\n", str);
37 		return(NULL);
38 	}
39 	data = um_kmalloc(sizeof(*data));
40 	if(data == NULL) return(NULL);
41 	*data = ((struct fd_chan) { .fd  	= n,
42 				    .raw  	= opts->raw });
43 	return(data);
44 }
45 
46 static int fd_open(int input, int output, int primary, void *d, char **dev_out)
47 {
48 	struct fd_chan *data = d;
49 	int err;
50 
51 	if(data->raw && isatty(data->fd)){
52 		CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
53 		if(err)
54 			return(err);
55 
56 		err = raw(data->fd);
57 		if(err)
58 			return(err);
59 	}
60 	sprintf(data->str, "%d", data->fd);
61 	*dev_out = data->str;
62 	return(data->fd);
63 }
64 
65 static void fd_close(int fd, void *d)
66 {
67 	struct fd_chan *data = d;
68 	int err;
69 
70 	if(data->raw && isatty(fd)){
71 		CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
72 		if(err)
73 			printk("Failed to restore terminal state - "
74 			       "errno = %d\n", -err);
75 		data->raw = 0;
76 	}
77 }
78 
79 struct chan_ops fd_ops = {
80 	.type		= "fd",
81 	.init		= fd_init,
82 	.open		= fd_open,
83 	.close		= fd_close,
84 	.read		= generic_read,
85 	.write		= generic_write,
86 	.console_write	= generic_console_write,
87 	.window_size	= generic_window_size,
88 	.free		= generic_free,
89 	.winch		= 1,
90 };
91 
92 /*
93  * Overrides for Emacs so that we follow Linus's tabbing style.
94  * Emacs will notice this stuff at the end of the file and automatically
95  * adjust the settings for this buffer only.  This must remain at the end
96  * of the file.
97  * ---------------------------------------------------------------------------
98  * Local variables:
99  * c-file-style: "linux"
100  * End:
101  */
102