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 "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");