arch/xtensa/platforms/iss/console.c

   1 /*
   2  * arch/xtensa/platforms/iss/console.c
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 2001-2005 Tensilica Inc.
   9  *   Authors    Christian Zankel, Joe Taylor
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/console.h>
  16 #include <linux/init.h>
  17 #include <linux/mm.h>
  18 #include <linux/major.h>
  19 #include <linux/param.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/serial.h>
  22
  23 #include <asm/uaccess.h>
  24 #include <asm/irq.h>
  25
  26 #include <platform/simcall.h>
  27
  28 #include <linux/tty.h>
  29 #include <linux/tty_flip.h>
  30
  31 #ifdef SERIAL_INLINE
  32 #define _INLINE_ inline
  33 #endif
  34
  35 #define SERIAL_MAX_NUM_LINES 1
  36 #define SERIAL_TIMER_VALUE (HZ / 10)
  37
  38 static struct tty_driver *serial_driver;
  39 static struct tty_port serial_port;
  40 static struct timer_list serial_timer;
  41
  42 static DEFINE_SPINLOCK(timer_lock);
  43
  44 static char *serial_version = "0.1";
  45 static char *serial_name = "ISS serial driver";
  46
  47 /*
  48  * This routine is called whenever a serial port is opened.  It
  49  * enables interrupts for a serial port, linking in its async structure into
  50  * the IRQ chain.   It also performs the serial-specific
  51  * initialization for the tty structure.
  52  */
  53
  54 static void rs_poll(unsigned long);
  55
  56 static int rs_open(struct tty_struct *tty, struct file * filp)
  57 {
  58         tty->port = &serial_port;
  59         spin_lock_bh(&timer_lock);
  60         if (tty->count == 1) {
  61                 setup_timer(&serial_timer, rs_poll,
  62                                 (unsigned long)&serial_port);
  63                 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
  64         }
  65         spin_unlock_bh(&timer_lock);
  66
  67         return 0;
  68 }
  69
  70
  71 /*
  72  * ------------------------------------------------------------
  73  * iss_serial_close()
  74  *
  75  * This routine is called when the serial port gets closed.  First, we
  76  * wait for the last remaining data to be sent.  Then, we unlink its
  77  * async structure from the interrupt chain if necessary, and we free
  78  * that IRQ if nothing is left in the chain.
  79  * ------------------------------------------------------------
  80  */
  81 static void rs_close(struct tty_struct *tty, struct file * filp)
  82 {
  83         spin_lock_bh(&timer_lock);
  84         if (tty->count == 1)
  85                 del_timer_sync(&serial_timer);
  86         spin_unlock_bh(&timer_lock);
  87 }
  88
  89
  90 static int rs_write(struct tty_struct * tty,
  91                     const unsigned char *buf, int count)
  92 {
  93         /* see drivers/char/serialX.c to reference original version */
  94
  95         simc_write(1, buf, count);
  96         return count;
  97 }
  98
  99 static void rs_poll(unsigned long priv)
 100 {
 101         struct tty_port *port = (struct tty_port *)priv;
 102         int i = 0;
 103         unsigned char c;
 104
 105         spin_lock(&timer_lock);
 106
 107         while (simc_poll(0)) {
 108                 simc_read(0, &c, 1);
 109                 tty_insert_flip_char(port, c, TTY_NORMAL);
 110                 i++;
 111         }
 112
 113         if (i)
 114                 tty_flip_buffer_push(port);
 115
 116
 117         mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
 118         spin_unlock(&timer_lock);
 119 }
 120
 121
 122 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 123 {
 124         return rs_write(tty, &ch, 1);
 125 }
 126
 127 static void rs_flush_chars(struct tty_struct *tty)
 128 {
 129 }
 130
 131 static int rs_write_room(struct tty_struct *tty)
 132 {
 133         /* Let's say iss can always accept 2K characters.. */
 134         return 2 * 1024;
 135 }
 136
 137 static int rs_chars_in_buffer(struct tty_struct *tty)
 138 {
 139         /* the iss doesn't buffer characters */
 140         return 0;
 141 }
 142
 143 static void rs_hangup(struct tty_struct *tty)
 144 {
 145         /* Stub, once again.. */
 146 }
 147
 148 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 149 {
 150         /* Stub, once again.. */
 151 }
 152
 153 static int rs_proc_show(struct seq_file *m, void *v)
 154 {
 155         seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
 156         return 0;
 157 }
 158
 159 static int rs_proc_open(struct inode *inode, struct file *file)
 160 {
 161         return single_open(file, rs_proc_show, NULL);
 162 }
 163
 164 static const struct file_operations rs_proc_fops = {
 165         .owner          = THIS_MODULE,
 166         .open           = rs_proc_open,
 167         .read           = seq_read,
 168         .llseek         = seq_lseek,
 169         .release        = single_release,
 170 };
 171
 172 static const struct tty_operations serial_ops = {
 173         .open = rs_open,
 174         .close = rs_close,
 175         .write = rs_write,
 176         .put_char = rs_put_char,
 177         .flush_chars = rs_flush_chars,
 178         .write_room = rs_write_room,
 179         .chars_in_buffer = rs_chars_in_buffer,
 180         .hangup = rs_hangup,
 181         .wait_until_sent = rs_wait_until_sent,
 182         .proc_fops = &rs_proc_fops,
 183 };
 184
 185 int __init rs_init(void)
 186 {
 187         tty_port_init(&serial_port);
 188
 189         serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
 190
 191         printk ("%s %s\n", serial_name, serial_version);
 192
 193         /* Initialize the tty_driver structure */
 194
 195         serial_driver->driver_name = "iss_serial";
 196         serial_driver->name = "ttyS";
 197         serial_driver->major = TTY_MAJOR;
 198         serial_driver->minor_start = 64;
 199         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
 200         serial_driver->subtype = SERIAL_TYPE_NORMAL;
 201         serial_driver->init_termios = tty_std_termios;
 202         serial_driver->init_termios.c_cflag =
 203                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 204         serial_driver->flags = TTY_DRIVER_REAL_RAW;
 205
 206         tty_set_operations(serial_driver, &serial_ops);
 207         tty_port_link_device(&serial_port, serial_driver, 0);
 208
 209         if (tty_register_driver(serial_driver))
 210                 panic("Couldn't register serial driver\n");
 211         return 0;
 212 }
 213
 214
 215 static __exit void rs_exit(void)
 216 {
 217         int error;
 218
 219         if ((error = tty_unregister_driver(serial_driver)))
 220                 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
 221                        error);
 222         put_tty_driver(serial_driver);
 223         tty_port_destroy(&serial_port);
 224 }
 225
 226
 227 /* We use `late_initcall' instead of just `__initcall' as a workaround for
 228  * the fact that (1) simcons_tty_init can't be called before tty_init,
 229  * (2) tty_init is called via `module_init', (3) if statically linked,
 230  * module_init == device_init, and (4) there's no ordering of init lists.
 231  * We can do this easily because simcons is always statically linked, but
 232  * other tty drivers that depend on tty_init and which must use
 233  * `module_init' to declare their init routines are likely to be broken.
 234  */
 235
 236 late_initcall(rs_init);
 237
 238
 239 #ifdef CONFIG_SERIAL_CONSOLE
 240
 241 static void iss_console_write(struct console *co, const char *s, unsigned count)
 242 {
 243         int len = strlen(s);
 244
 245         if (s != 0 && *s != 0)
 246                 simc_write(1, s, count < len ? count : len);
 247 }
 248
 249 static struct tty_driver* iss_console_device(struct console *c, int *index)
 250 {
 251         *index = c->index;
 252         return serial_driver;
 253 }
 254
 255
 256 static struct console sercons = {
 257         .name = "ttyS",
 258         .write = iss_console_write,
 259         .device = iss_console_device,
 260         .flags = CON_PRINTBUFFER,
 261         .index = -1
 262 };
 263
 264 static int __init iss_console_init(void)
 265 {
 266         register_console(&sercons);
 267         return 0;
 268 }
 269
 270 console_initcall(iss_console_init);
 271
 272 #endif /* CONFIG_SERIAL_CONSOLE */
 273