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(&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(&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         struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
 103         int i = 0;
 104         unsigned char c;
 105
 106         spin_lock(&timer_lock);
 107
 108         while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){
 109                 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0);
 110                 tty_insert_flip_char(port, c, TTY_NORMAL);
 111                 i++;
 112         }
 113
 114         if (i)
 115                 tty_flip_buffer_push(port);
 116
 117
 118         mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
 119         spin_unlock(&timer_lock);
 120 }
 121
 122
 123 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 124 {
 125         return rs_write(tty, &ch, 1);
 126 }
 127
 128 static void rs_flush_chars(struct tty_struct *tty)
 129 {
 130 }
 131
 132 static int rs_write_room(struct tty_struct *tty)
 133 {
 134         /* Let's say iss can always accept 2K characters.. */
 135         return 2 * 1024;
 136 }
 137
 138 static int rs_chars_in_buffer(struct tty_struct *tty)
 139 {
 140         /* the iss doesn't buffer characters */
 141         return 0;
 142 }
 143
 144 static void rs_hangup(struct tty_struct *tty)
 145 {
 146         /* Stub, once again.. */
 147 }
 148
 149 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 150 {
 151         /* Stub, once again.. */
 152 }
 153
 154 static int rs_proc_show(struct seq_file *m, void *v)
 155 {
 156         seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
 157         return 0;
 158 }
 159
 160 static int rs_proc_open(struct inode *inode, struct file *file)
 161 {
 162         return single_open(file, rs_proc_show, NULL);
 163 }
 164
 165 static const struct file_operations rs_proc_fops = {
 166         .owner          = THIS_MODULE,
 167         .open           = rs_proc_open,
 168         .read           = seq_read,
 169         .llseek         = seq_lseek,
 170         .release        = single_release,
 171 };
 172
 173 static const struct tty_operations serial_ops = {
 174         .open = rs_open,
 175         .close = rs_close,
 176         .write = rs_write,
 177         .put_char = rs_put_char,
 178         .flush_chars = rs_flush_chars,
 179         .write_room = rs_write_room,
 180         .chars_in_buffer = rs_chars_in_buffer,
 181         .hangup = rs_hangup,
 182         .wait_until_sent = rs_wait_until_sent,
 183         .proc_fops = &rs_proc_fops,
 184 };
 185
 186 int __init rs_init(void)
 187 {
 188         tty_port_init(&serial_port);
 189
 190         serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
 191
 192         printk ("%s %s\n", serial_name, serial_version);
 193
 194         /* Initialize the tty_driver structure */
 195
 196         serial_driver->driver_name = "iss_serial";
 197         serial_driver->name = "ttyS";
 198         serial_driver->major = TTY_MAJOR;
 199         serial_driver->minor_start = 64;
 200         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
 201         serial_driver->subtype = SERIAL_TYPE_NORMAL;
 202         serial_driver->init_termios = tty_std_termios;
 203         serial_driver->init_termios.c_cflag =
 204                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 205         serial_driver->flags = TTY_DRIVER_REAL_RAW;
 206
 207         tty_set_operations(serial_driver, &serial_ops);
 208         tty_port_link_device(&serial_port, serial_driver, 0);
 209
 210         if (tty_register_driver(serial_driver))
 211                 panic("Couldn't register serial driver\n");
 212         return 0;
 213 }
 214
 215
 216 static __exit void rs_exit(void)
 217 {
 218         int error;
 219
 220         if ((error = tty_unregister_driver(serial_driver)))
 221                 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
 222                        error);
 223         put_tty_driver(serial_driver);
 224         tty_port_destroy(&serial_port);
 225 }
 226
 227
 228 /* We use `late_initcall' instead of just `__initcall' as a workaround for
 229  * the fact that (1) simcons_tty_init can't be called before tty_init,
 230  * (2) tty_init is called via `module_init', (3) if statically linked,
 231  * module_init == device_init, and (4) there's no ordering of init lists.
 232  * We can do this easily because simcons is always statically linked, but
 233  * other tty drivers that depend on tty_init and which must use
 234  * `module_init' to declare their init routines are likely to be broken.
 235  */
 236
 237 late_initcall(rs_init);
 238
 239
 240 #ifdef CONFIG_SERIAL_CONSOLE
 241
 242 static void iss_console_write(struct console *co, const char *s, unsigned count)
 243 {
 244         int len = strlen(s);
 245
 246         if (s != 0 && *s != 0)
 247                 __simc (SYS_write, 1, (unsigned long)s,
 248                         count < len ? count : len,0,0);
 249 }
 250
 251 static struct tty_driver* iss_console_device(struct console *c, int *index)
 252 {
 253         *index = c->index;
 254         return serial_driver;
 255 }
 256
 257
 258 static struct console sercons = {
 259         .name = "ttyS",
 260         .write = iss_console_write,
 261         .device = iss_console_device,
 262         .flags = CON_PRINTBUFFER,
 263         .index = -1
 264 };
 265
 266 static int __init iss_console_init(void)
 267 {
 268         register_console(&sercons);
 269         return 0;
 270 }
 271
 272 console_initcall(iss_console_init);
 273
 274 #endif /* CONFIG_SERIAL_CONSOLE */
 275