xref: /linux/arch/um/drivers/ssl.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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 };
46 
47 static int ssl_config(char *str, char **error_out);
48 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
49 static int ssl_remove(int n, char **error_out);
50 
51 
52 /* Const, except for .mc.list */
53 static struct line_driver driver = {
54 	.name 			= "UML serial line",
55 	.device_name 		= "ttyS",
56 	.major 			= TTY_MAJOR,
57 	.minor_start 		= 64,
58 	.type 		 	= TTY_DRIVER_TYPE_SERIAL,
59 	.subtype 	 	= 0,
60 	.read_irq 		= SSL_IRQ,
61 	.read_irq_name 		= "ssl",
62 	.write_irq 		= SSL_WRITE_IRQ,
63 	.write_irq_name 	= "ssl-write",
64 	.mc  = {
65 		.list		= LIST_HEAD_INIT(driver.mc.list),
66 		.name  		= "ssl",
67 		.config 	= ssl_config,
68 		.get_config 	= ssl_get_config,
69 		.id		= line_id,
70 		.remove 	= ssl_remove,
71 	},
72 };
73 
74 /* The array is initialized by line_init, at initcall time.  The
75  * elements are locked individually as needed.
76  */
77 static struct line serial_lines[NR_PORTS] =
78 	{ [0 ... NR_PORTS - 1] = LINE_INIT(CONFIG_SSL_CHAN, &driver) };
79 
80 static int ssl_config(char *str, char **error_out)
81 {
82 	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
83 			   error_out);
84 }
85 
86 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
87 {
88 	return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
89 			       size, error_out);
90 }
91 
92 static int ssl_remove(int n, char **error_out)
93 {
94 	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
95 			   error_out);
96 }
97 
98 static int ssl_open(struct tty_struct *tty, struct file *filp)
99 {
100 	int err = line_open(serial_lines, tty);
101 
102 	if (err)
103 		printk(KERN_ERR "Failed to open serial line %d, err = %d\n",
104 		       tty->index, err);
105 
106 	return err;
107 }
108 
109 #if 0
110 static void ssl_flush_buffer(struct tty_struct *tty)
111 {
112 	return;
113 }
114 
115 static void ssl_stop(struct tty_struct *tty)
116 {
117 	printk(KERN_ERR "Someone should implement ssl_stop\n");
118 }
119 
120 static void ssl_start(struct tty_struct *tty)
121 {
122 	printk(KERN_ERR "Someone should implement ssl_start\n");
123 }
124 
125 void ssl_hangup(struct tty_struct *tty)
126 {
127 }
128 #endif
129 
130 static const struct tty_operations ssl_ops = {
131 	.open 	 		= ssl_open,
132 	.close 	 		= line_close,
133 	.write 	 		= line_write,
134 	.put_char 		= line_put_char,
135 	.write_room		= line_write_room,
136 	.chars_in_buffer 	= line_chars_in_buffer,
137 	.flush_buffer 		= line_flush_buffer,
138 	.flush_chars 		= line_flush_chars,
139 	.set_termios 		= line_set_termios,
140 	.ioctl 	 		= line_ioctl,
141 	.throttle 		= line_throttle,
142 	.unthrottle 		= line_unthrottle,
143 #if 0
144 	.stop 	 		= ssl_stop,
145 	.start 	 		= ssl_start,
146 	.hangup 	 	= ssl_hangup,
147 #endif
148 };
149 
150 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
151  * by being an initcall and exitcall, respectively.
152  */
153 static int ssl_init_done = 0;
154 
155 static void ssl_console_write(struct console *c, const char *string,
156 			      unsigned len)
157 {
158 	struct line *line = &serial_lines[c->index];
159 	unsigned long flags;
160 
161 	spin_lock_irqsave(&line->lock, flags);
162 	console_write_chan(&line->chan_list, string, len);
163 	spin_unlock_irqrestore(&line->lock, flags);
164 }
165 
166 static struct tty_driver *ssl_console_device(struct console *c, int *index)
167 {
168 	*index = c->index;
169 	return ssl_driver;
170 }
171 
172 static int ssl_console_setup(struct console *co, char *options)
173 {
174 	struct line *line = &serial_lines[co->index];
175 
176 	return console_open_chan(line, co);
177 }
178 
179 /* No locking for register_console call - relies on single-threaded initcalls */
180 static struct console ssl_cons = {
181 	.name		= "ttyS",
182 	.write		= ssl_console_write,
183 	.device		= ssl_console_device,
184 	.setup		= ssl_console_setup,
185 	.flags		= CON_PRINTBUFFER|CON_ANYTIME,
186 	.index		= -1,
187 };
188 
189 static int ssl_init(void)
190 {
191 	char *new_title;
192 
193 	printk(KERN_INFO "Initializing software serial port version %d\n",
194 	       ssl_version);
195 	ssl_driver = register_lines(&driver, &ssl_ops, serial_lines,
196 				    ARRAY_SIZE(serial_lines));
197 
198 	new_title = add_xterm_umid(opts.xterm_title);
199 	if (new_title != NULL)
200 		opts.xterm_title = new_title;
201 
202 	lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
203 
204 	ssl_init_done = 1;
205 	register_console(&ssl_cons);
206 	return 0;
207 }
208 late_initcall(ssl_init);
209 
210 static void ssl_exit(void)
211 {
212 	if (!ssl_init_done)
213 		return;
214 	close_lines(serial_lines, ARRAY_SIZE(serial_lines));
215 }
216 __uml_exitcall(ssl_exit);
217 
218 static int ssl_chan_setup(char *str)
219 {
220 	char *error;
221 	int ret;
222 
223 	ret = line_setup(serial_lines, ARRAY_SIZE(serial_lines), str, &error);
224 	if(ret < 0)
225 		printk(KERN_ERR "Failed to set up serial line with "
226 		       "configuration string \"%s\" : %s\n", str, error);
227 
228 	return 1;
229 }
230 
231 __setup("ssl", ssl_chan_setup);
232 __channel_help(ssl_chan_setup, "ssl");
233