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 "ssl.h"
  16 #include "chan.h"
  17 #include "init.h"
  18 #include "irq_user.h"
  19 #include "mconsole_kern.h"
  20
  21 static const int ssl_version = 1;
  22
  23 /* Referenced only by tty_driver below - presumably it's locked correctly
  24  * by the tty driver.
  25  */
  26
  27 static struct tty_driver *ssl_driver;
  28
  29 #define NR_PORTS 64
  30
  31 static void ssl_announce(char *dev_name, int dev)
  32 {
  33         printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
  34                dev_name);
  35 }
  36
  37 /* Almost const, except that xterm_title may be changed in an initcall */
  38 static struct chan_opts opts = {
  39         .announce       = ssl_announce,
  40         .xterm_title    = "Serial Line #%d",
  41         .raw            = 1,
  42 };
  43
  44 static int ssl_config(char *str, char **error_out);
  45 static int ssl_get_config(char *dev, char *str, int size, char **error_out);
  46 static int ssl_remove(int n, char **error_out);
  47
  48
  49 /* Const, except for .mc.list */
  50 static struct line_driver driver = {
  51         .name                   = "UML serial line",
  52         .device_name            = "ttyS",
  53         .major                  = TTY_MAJOR,
  54         .minor_start            = 64,
  55         .type                   = TTY_DRIVER_TYPE_SERIAL,
  56         .subtype                = 0,
  57         .read_irq               = SSL_IRQ,
  58         .read_irq_name          = "ssl",
  59         .write_irq              = SSL_WRITE_IRQ,
  60         .write_irq_name         = "ssl-write",
  61         .mc  = {
  62                 .list           = LIST_HEAD_INIT(driver.mc.list),
  63                 .name           = "ssl",
  64                 .config         = ssl_config,
  65                 .get_config     = ssl_get_config,
  66                 .id             = line_id,
  67                 .remove         = ssl_remove,
  68         },
  69 };
  70
  71 /* The array is initialized by line_init, at initcall time.  The
  72  * elements are locked individually as needed.
  73  */
  74 static char *conf[NR_PORTS];
  75 static char *def_conf = CONFIG_SSL_CHAN;
  76 static struct line serial_lines[NR_PORTS];
  77
  78 static int ssl_config(char *str, char **error_out)
  79 {
  80         return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
  81                            error_out);
  82 }
  83
  84 static int ssl_get_config(char *dev, char *str, int size, char **error_out)
  85 {
  86         return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
  87                                size, error_out);
  88 }
  89
  90 static int ssl_remove(int n, char **error_out)
  91 {
  92         return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
  93                            error_out);
  94 }
  95
  96 static int ssl_open(struct tty_struct *tty, struct file *filp)
  97 {
  98         int err = line_open(serial_lines, tty);
  99
 100         if (err)
 101                 printk(KERN_ERR "Failed to open serial line %d, err = %d\n",
 102                        tty->index, err);
 103
 104         return err;
 105 }
 106
 107 #if 0
 108 static void ssl_flush_buffer(struct tty_struct *tty)
 109 {
 110         return;
 111 }
 112
 113 static void ssl_stop(struct tty_struct *tty)
 114 {
 115         printk(KERN_ERR "Someone should implement ssl_stop\n");
 116 }
 117
 118 static void ssl_start(struct tty_struct *tty)
 119 {
 120         printk(KERN_ERR "Someone should implement ssl_start\n");
 121 }
 122
 123 void ssl_hangup(struct tty_struct *tty)
 124 {
 125 }
 126 #endif
 127
 128 static const struct tty_operations ssl_ops = {
 129         .open                   = ssl_open,
 130         .close                  = line_close,
 131         .write                  = line_write,
 132         .put_char               = line_put_char,
 133         .write_room             = line_write_room,
 134         .chars_in_buffer        = line_chars_in_buffer,
 135         .flush_buffer           = line_flush_buffer,
 136         .flush_chars            = line_flush_chars,
 137         .set_termios            = line_set_termios,
 138         .ioctl                  = line_ioctl,
 139         .throttle               = line_throttle,
 140         .unthrottle             = line_unthrottle,
 141 #if 0
 142         .stop                   = ssl_stop,
 143         .start                  = ssl_start,
 144         .hangup                 = ssl_hangup,
 145 #endif
 146 };
 147
 148 /* Changed by ssl_init and referenced by ssl_exit, which are both serialized
 149  * by being an initcall and exitcall, respectively.
 150  */
 151 static int ssl_init_done = 0;
 152
 153 static void ssl_console_write(struct console *c, const char *string,
 154                               unsigned len)
 155 {
 156         struct line *line = &serial_lines[c->index];
 157         unsigned long flags;
 158
 159         spin_lock_irqsave(&line->lock, flags);
 160         console_write_chan(&line->chan_list, string, len);
 161         spin_unlock_irqrestore(&line->lock, flags);
 162 }
 163
 164 static struct tty_driver *ssl_console_device(struct console *c, int *index)
 165 {
 166         *index = c->index;
 167         return ssl_driver;
 168 }
 169
 170 static int ssl_console_setup(struct console *co, char *options)
 171 {
 172         struct line *line = &serial_lines[co->index];
 173
 174         return console_open_chan(line, co);
 175 }
 176
 177 /* No locking for register_console call - relies on single-threaded initcalls */
 178 static struct console ssl_cons = {
 179         .name           = "ttyS",
 180         .write          = ssl_console_write,
 181         .device         = ssl_console_device,
 182         .setup          = ssl_console_setup,
 183         .flags          = CON_PRINTBUFFER|CON_ANYTIME,
 184         .index          = -1,
 185 };
 186
 187 static int ssl_init(void)
 188 {
 189         char *new_title;
 190         int i;
 191
 192         printk(KERN_INFO "Initializing software serial port version %d\n",
 193                ssl_version);
 194
 195         for (i = 0; i < NR_PORTS; i++) {
 196                 char *s = conf[i];
 197                 if (!s)
 198                         s = def_conf;
 199                 if (s && strcmp(s, "none") != 0) {
 200                         serial_lines[i].init_str = s;
 201                         serial_lines[i].valid = 1;
 202                 }
 203                 spin_lock_init(&serial_lines[i].lock);
 204                 spin_lock_init(&serial_lines[i].count_lock);
 205                 serial_lines[i].driver = &driver;
 206         }
 207         ssl_driver = register_lines(&driver, &ssl_ops, serial_lines,
 208                                     ARRAY_SIZE(serial_lines));
 209
 210         new_title = add_xterm_umid(opts.xterm_title);
 211         if (new_title != NULL)
 212                 opts.xterm_title = new_title;
 213
 214         lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
 215
 216         ssl_init_done = 1;
 217         register_console(&ssl_cons);
 218         return 0;
 219 }
 220 late_initcall(ssl_init);
 221
 222 static void ssl_exit(void)
 223 {
 224         if (!ssl_init_done)
 225                 return;
 226         close_lines(serial_lines, ARRAY_SIZE(serial_lines));
 227 }
 228 __uml_exitcall(ssl_exit);
 229
 230 static int ssl_chan_setup(char *str)
 231 {
 232         line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
 233         return 1;
 234 }
 235
 236 __setup("ssl", ssl_chan_setup);
 237 __channel_help(ssl_chan_setup, "ssl");