xref: /linux/arch/um/drivers/ssl.c (revision f8343685643f2901fe11aa9d0358cafbeaf7b4c3)
1 /*
2  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/fs.h"
7 #include "linux/tty.h"
8 #include "linux/tty_driver.h"
9 #include "linux/major.h"
10 #include "linux/mm.h"
11 #include "linux/init.h"
12 #include "linux/console.h"
13 #include "asm/termbits.h"
14 #include "asm/irq.h"
15 #include "line.h"
16 #include "ssl.h"
17 #include "chan_kern.h"
18 #include "kern_util.h"
19 #include "kern.h"
20 #include "init.h"
21 #include "irq_user.h"
22 #include "mconsole_kern.h"
23 
24 static const int ssl_version = 1;
25 
26 /* Referenced only by tty_driver below - presumably it's locked correctly
27  * by the tty driver.
28  */
29 
30 static struct tty_driver *ssl_driver;
31 
32 #define NR_PORTS 64
33 
34 static void ssl_announce(char *dev_name, int dev)
35 {
36 	printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
37 	       dev_name);
38 }
39 
40 /* Almost const, except that xterm_title may be changed in an initcall */
41 static struct chan_opts opts = {
42 	.announce 	= ssl_announce,
43 	.xterm_title	= "Serial Line #%d",
44 	.raw		= 1,
45 	.tramp_stack 	= 0,
46 	.in_kernel 	= 1,
47 };
48 
49 static int ssl_config(char *str, char **error_out);
50 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
51 static int ssl_remove(int n, char **error_out);
52 
53 
54 /* Const, except for .mc.list */
55 static struct line_driver driver = {
56 	.name 			= "UML serial line",
57 	.device_name 		= "ttyS",
58 	.major 			= TTY_MAJOR,
59 	.minor_start 		= 64,
60 	.type 		 	= TTY_DRIVER_TYPE_SERIAL,
61 	.subtype 	 	= 0,
62 	.read_irq 		= SSL_IRQ,
63 	.read_irq_name 		= "ssl",
64 	.write_irq 		= SSL_WRITE_IRQ,
65 	.write_irq_name 	= "ssl-write",
66 	.mc  = {
67 		.list		= LIST_HEAD_INIT(driver.mc.list),
68 		.name  		= "ssl",
69 		.config 	= ssl_config,
70 		.get_config 	= ssl_get_config,
71 		.id		= line_id,
72 		.remove 	= ssl_remove,
73 	},
74 };
75 
76 /* The array is initialized by line_init, at initcall time.  The
77  * elements are locked individually as needed.
78  */
79 static struct line serial_lines[NR_PORTS] =
80 	{ [0 ... NR_PORTS - 1] = LINE_INIT(CONFIG_SSL_CHAN, &driver) };
81 
82 static int ssl_config(char *str, char **error_out)
83 {
84 	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
85 			   error_out);
86 }
87 
88 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
89 {
90 	return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
91 			       size, error_out);
92 }
93 
94 static int ssl_remove(int n, char **error_out)
95 {
96 	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
97 			   error_out);
98 }
99 
100 static int ssl_open(struct tty_struct *tty, struct file *filp)
101 {
102 	return line_open(serial_lines, tty);
103 }
104 
105 #if 0
106 static void ssl_flush_buffer(struct tty_struct *tty)
107 {
108 	return;
109 }
110 
111 static void ssl_stop(struct tty_struct *tty)
112 {
113 	printk(KERN_ERR "Someone should implement ssl_stop\n");
114 }
115 
116 static void ssl_start(struct tty_struct *tty)
117 {
118 	printk(KERN_ERR "Someone should implement ssl_start\n");
119 }
120 
121 void ssl_hangup(struct tty_struct *tty)
122 {
123 }
124 #endif
125 
126 static const struct tty_operations ssl_ops = {
127 	.open 	 		= ssl_open,
128 	.close 	 		= line_close,
129 	.write 	 		= line_write,
130 	.put_char 		= line_put_char,
131 	.write_room		= line_write_room,
132 	.chars_in_buffer 	= line_chars_in_buffer,
133 	.flush_buffer 		= line_flush_buffer,
134 	.flush_chars 		= line_flush_chars,
135 	.set_termios 		= line_set_termios,
136 	.ioctl 	 		= line_ioctl,
137 	.throttle 		= line_throttle,
138 	.unthrottle 		= line_unthrottle,
139 #if 0
140 	.stop 	 		= ssl_stop,
141 	.start 	 		= ssl_start,
142 	.hangup 	 	= ssl_hangup,
143 #endif
144 };
145 
146 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
147  * by being an initcall and exitcall, respectively.
148  */
149 static int ssl_init_done = 0;
150 
151 static void ssl_console_write(struct console *c, const char *string,
152 			      unsigned len)
153 {
154 	struct line *line = &serial_lines[c->index];
155 	unsigned long flags;
156 
157 	spin_lock_irqsave(&line->lock, flags);
158 	console_write_chan(&line->chan_list, string, len);
159 	spin_unlock_irqrestore(&line->lock, flags);
160 }
161 
162 static struct tty_driver *ssl_console_device(struct console *c, int *index)
163 {
164 	*index = c->index;
165 	return ssl_driver;
166 }
167 
168 static int ssl_console_setup(struct console *co, char *options)
169 {
170 	struct line *line = &serial_lines[co->index];
171 
172 	return console_open_chan(line, co);
173 }
174 
175 /* No locking for register_console call - relies on single-threaded initcalls */
176 static struct console ssl_cons = {
177 	.name		= "ttyS",
178 	.write		= ssl_console_write,
179 	.device		= ssl_console_device,
180 	.setup		= ssl_console_setup,
181 	.flags		= CON_PRINTBUFFER|CON_ANYTIME,
182 	.index		= -1,
183 };
184 
185 static int ssl_init(void)
186 {
187 	char *new_title;
188 
189 	printk(KERN_INFO "Initializing software serial port version %d\n",
190 	       ssl_version);
191 	ssl_driver = register_lines(&driver, &ssl_ops, serial_lines,
192 				    ARRAY_SIZE(serial_lines));
193 
194 	new_title = add_xterm_umid(opts.xterm_title);
195 	if (new_title != NULL)
196 		opts.xterm_title = new_title;
197 
198 	lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
199 
200 	ssl_init_done = 1;
201 	register_console(&ssl_cons);
202 	return 0;
203 }
204 late_initcall(ssl_init);
205 
206 static void ssl_exit(void)
207 {
208 	if (!ssl_init_done)
209 		return;
210 	close_lines(serial_lines, ARRAY_SIZE(serial_lines));
211 }
212 __uml_exitcall(ssl_exit);
213 
214 static int ssl_chan_setup(char *str)
215 {
216 	char *error;
217 	int ret;
218 
219 	ret = line_setup(serial_lines, ARRAY_SIZE(serial_lines), str, &error);
220 	if(ret < 0)
221 		printk(KERN_ERR "Failed to set up serial line with "
222 		       "configuration string \"%s\" : %s\n", str, error);
223 
224 	return 1;
225 }
226 
227 __setup("ssl", ssl_chan_setup);
228 __channel_help(ssl_chan_setup, "ssl");
229