xref: /openbmc/linux/arch/um/drivers/tty.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
4  */
5 
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <termios.h>
9 #include "chan_user.h"
10 #include <os.h>
11 #include <um_malloc.h>
12 
13 struct tty_chan {
14 	char *dev;
15 	int raw;
16 	struct termios tt;
17 };
18 
19 static void *tty_chan_init(char *str, int device, const struct chan_opts *opts)
20 {
21 	struct tty_chan *data;
22 
23 	if (*str != ':') {
24 		printk(UM_KERN_ERR "tty_init : channel type 'tty' must specify "
25 		       "a device\n");
26 		return NULL;
27 	}
28 	str++;
29 
30 	data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
31 	if (data == NULL)
32 		return NULL;
33 	*data = ((struct tty_chan) { .dev 	= str,
34 				     .raw 	= opts->raw });
35 
36 	return data;
37 }
38 
39 static int tty_open(int input, int output, int primary, void *d,
40 		    char **dev_out)
41 {
42 	struct tty_chan *data = d;
43 	int fd, err, mode = 0;
44 
45 	if (input && output)
46 		mode = O_RDWR;
47 	else if (input)
48 		mode = O_RDONLY;
49 	else if (output)
50 		mode = O_WRONLY;
51 
52 	fd = open(data->dev, mode);
53 	if (fd < 0)
54 		return -errno;
55 
56 	if (data->raw) {
57 		CATCH_EINTR(err = tcgetattr(fd, &data->tt));
58 		if (err)
59 			return err;
60 
61 		err = raw(fd);
62 		if (err)
63 			return err;
64 	}
65 
66 	*dev_out = data->dev;
67 	return fd;
68 }
69 
70 const struct chan_ops tty_ops = {
71 	.type		= "tty",
72 	.init		= tty_chan_init,
73 	.open		= tty_open,
74 	.close		= generic_close,
75 	.read		= generic_read,
76 	.write		= generic_write,
77 	.console_write	= generic_console_write,
78 	.window_size	= generic_window_size,
79 	.free		= generic_free,
80 	.winch		= 0,
81 };
82