xref: /openbmc/linux/arch/um/drivers/ssl.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
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 "chan.h"
16 #include <init.h>
17 #include <irq_user.h>
18 #include "mconsole_kern.h"
19 
20 static const int ssl_version = 1;
21 
22 #define NR_PORTS 64
23 
24 static void ssl_announce(char *dev_name, int dev)
25 {
26 	printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
27 	       dev_name);
28 }
29 
30 /* Almost const, except that xterm_title may be changed in an initcall */
31 static struct chan_opts opts = {
32 	.announce 	= ssl_announce,
33 	.xterm_title	= "Serial Line #%d",
34 	.raw		= 1,
35 };
36 
37 static int ssl_config(char *str, char **error_out);
38 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
39 static int ssl_remove(int n, char **error_out);
40 
41 
42 /* Const, except for .mc.list */
43 static struct line_driver driver = {
44 	.name 			= "UML serial line",
45 	.device_name 		= "ttyS",
46 	.major 			= TTY_MAJOR,
47 	.minor_start 		= 64,
48 	.type 		 	= TTY_DRIVER_TYPE_SERIAL,
49 	.subtype 	 	= 0,
50 	.read_irq 		= SSL_IRQ,
51 	.read_irq_name 		= "ssl",
52 	.write_irq 		= SSL_WRITE_IRQ,
53 	.write_irq_name 	= "ssl-write",
54 	.mc  = {
55 		.list		= LIST_HEAD_INIT(driver.mc.list),
56 		.name  		= "ssl",
57 		.config 	= ssl_config,
58 		.get_config 	= ssl_get_config,
59 		.id		= line_id,
60 		.remove 	= ssl_remove,
61 	},
62 };
63 
64 /* The array is initialized by line_init, at initcall time.  The
65  * elements are locked individually as needed.
66  */
67 static char *conf[NR_PORTS];
68 static char *def_conf = CONFIG_SSL_CHAN;
69 static struct line serial_lines[NR_PORTS];
70 
71 static int ssl_config(char *str, char **error_out)
72 {
73 	return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
74 			   error_out);
75 }
76 
77 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
78 {
79 	return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
80 			       size, error_out);
81 }
82 
83 static int ssl_remove(int n, char **error_out)
84 {
85 	return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
86 			   error_out);
87 }
88 
89 static int ssl_install(struct tty_driver *driver, struct tty_struct *tty)
90 {
91 	return line_install(driver, tty, &serial_lines[tty->index]);
92 }
93 
94 static const struct tty_operations ssl_ops = {
95 	.open 	 		= line_open,
96 	.close 	 		= line_close,
97 	.write 	 		= line_write,
98 	.put_char 		= line_put_char,
99 	.write_room		= line_write_room,
100 	.chars_in_buffer 	= line_chars_in_buffer,
101 	.flush_buffer 		= line_flush_buffer,
102 	.flush_chars 		= line_flush_chars,
103 	.set_termios 		= line_set_termios,
104 	.throttle 		= line_throttle,
105 	.unthrottle 		= line_unthrottle,
106 	.install		= ssl_install,
107 	.hangup			= line_hangup,
108 };
109 
110 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
111  * by being an initcall and exitcall, respectively.
112  */
113 static int ssl_init_done = 0;
114 
115 static void ssl_console_write(struct console *c, const char *string,
116 			      unsigned len)
117 {
118 	struct line *line = &serial_lines[c->index];
119 	unsigned long flags;
120 
121 	spin_lock_irqsave(&line->lock, flags);
122 	console_write_chan(line->chan_out, string, len);
123 	spin_unlock_irqrestore(&line->lock, flags);
124 }
125 
126 static struct tty_driver *ssl_console_device(struct console *c, int *index)
127 {
128 	*index = c->index;
129 	return driver.driver;
130 }
131 
132 static int ssl_console_setup(struct console *co, char *options)
133 {
134 	struct line *line = &serial_lines[co->index];
135 
136 	return console_open_chan(line, co);
137 }
138 
139 /* No locking for register_console call - relies on single-threaded initcalls */
140 static struct console ssl_cons = {
141 	.name		= "ttyS",
142 	.write		= ssl_console_write,
143 	.device		= ssl_console_device,
144 	.setup		= ssl_console_setup,
145 	.flags		= CON_PRINTBUFFER|CON_ANYTIME,
146 	.index		= -1,
147 };
148 
149 static int ssl_init(void)
150 {
151 	char *new_title;
152 	int err;
153 	int i;
154 
155 	printk(KERN_INFO "Initializing software serial port version %d\n",
156 	       ssl_version);
157 
158 	err = register_lines(&driver, &ssl_ops, serial_lines,
159 				    ARRAY_SIZE(serial_lines));
160 	if (err)
161 		return err;
162 
163 	new_title = add_xterm_umid(opts.xterm_title);
164 	if (new_title != NULL)
165 		opts.xterm_title = new_title;
166 
167 	for (i = 0; i < NR_PORTS; i++) {
168 		char *error;
169 		char *s = conf[i];
170 		if (!s)
171 			s = def_conf;
172 		if (setup_one_line(serial_lines, i, s, &opts, &error))
173 			printk(KERN_ERR "setup_one_line failed for "
174 			       "device %d : %s\n", i, error);
175 	}
176 
177 	ssl_init_done = 1;
178 	register_console(&ssl_cons);
179 	return 0;
180 }
181 late_initcall(ssl_init);
182 
183 static void ssl_exit(void)
184 {
185 	if (!ssl_init_done)
186 		return;
187 	close_lines(serial_lines, ARRAY_SIZE(serial_lines));
188 }
189 __uml_exitcall(ssl_exit);
190 
191 static int ssl_chan_setup(char *str)
192 {
193 	line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
194 	return 1;
195 }
196 
197 __setup("ssl", ssl_chan_setup);
198 __channel_help(ssl_chan_setup, "ssl");
199