arch/um/drivers/ssl.c

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