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 <linux/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 #define SERIAL_MAX_NUM_LINES 1
  32 #define SERIAL_TIMER_VALUE (HZ / 10)
  33
  34 static void rs_poll(struct timer_list *);
  35
  36 static struct tty_driver *serial_driver;
  37 static struct tty_port serial_port;
  38 static DEFINE_TIMER(serial_timer, rs_poll);
  39 static DEFINE_SPINLOCK(timer_lock);
  40
  41 static int rs_open(struct tty_struct *tty, struct file * filp)
  42 {
  43         spin_lock_bh(&timer_lock);
  44         if (tty->count == 1)
  45                 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
  46         spin_unlock_bh(&timer_lock);
  47
  48         return 0;
  49 }
  50
  51 static void rs_close(struct tty_struct *tty, struct file * filp)
  52 {
  53         spin_lock_bh(&timer_lock);
  54         if (tty->count == 1)
  55                 del_timer_sync(&serial_timer);
  56         spin_unlock_bh(&timer_lock);
  57 }
  58
  59
  60 static int rs_write(struct tty_struct * tty,
  61                     const unsigned char *buf, int count)
  62 {
  63         /* see drivers/char/serialX.c to reference original version */
  64
  65         simc_write(1, buf, count);
  66         return count;
  67 }
  68
  69 static void rs_poll(struct timer_list *unused)
  70 {
  71         struct tty_port *port = &serial_port;
  72         int i = 0;
  73         int rd = 1;
  74         unsigned char c;
  75
  76         spin_lock(&timer_lock);
  77
  78         while (simc_poll(0)) {
  79                 rd = simc_read(0, &c, 1);
  80                 if (rd <= 0)
  81                         break;
  82                 tty_insert_flip_char(port, c, TTY_NORMAL);
  83                 i++;
  84         }
  85
  86         if (i)
  87                 tty_flip_buffer_push(port);
  88         if (rd)
  89                 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
  90         spin_unlock(&timer_lock);
  91 }
  92
  93
  94 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
  95 {
  96         return rs_write(tty, &ch, 1);
  97 }
  98
  99 static void rs_flush_chars(struct tty_struct *tty)
 100 {
 101 }
 102
 103 static int rs_write_room(struct tty_struct *tty)
 104 {
 105         /* Let's say iss can always accept 2K characters.. */
 106         return 2 * 1024;
 107 }
 108
 109 static int rs_chars_in_buffer(struct tty_struct *tty)
 110 {
 111         /* the iss doesn't buffer characters */
 112         return 0;
 113 }
 114
 115 static void rs_hangup(struct tty_struct *tty)
 116 {
 117         /* Stub, once again.. */
 118 }
 119
 120 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 121 {
 122         /* Stub, once again.. */
 123 }
 124
 125 static int rs_proc_show(struct seq_file *m, void *v)
 126 {
 127         seq_printf(m, "serinfo:1.0 driver:0.1\n");
 128         return 0;
 129 }
 130
 131 static const struct tty_operations serial_ops = {
 132         .open = rs_open,
 133         .close = rs_close,
 134         .write = rs_write,
 135         .put_char = rs_put_char,
 136         .flush_chars = rs_flush_chars,
 137         .write_room = rs_write_room,
 138         .chars_in_buffer = rs_chars_in_buffer,
 139         .hangup = rs_hangup,
 140         .wait_until_sent = rs_wait_until_sent,
 141         .proc_show = rs_proc_show,
 142 };
 143
 144 static int __init rs_init(void)
 145 {
 146         tty_port_init(&serial_port);
 147
 148         serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
 149
 150         /* Initialize the tty_driver structure */
 151
 152         serial_driver->driver_name = "iss_serial";
 153         serial_driver->name = "ttyS";
 154         serial_driver->major = TTY_MAJOR;
 155         serial_driver->minor_start = 64;
 156         serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
 157         serial_driver->subtype = SERIAL_TYPE_NORMAL;
 158         serial_driver->init_termios = tty_std_termios;
 159         serial_driver->init_termios.c_cflag =
 160                 B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 161         serial_driver->flags = TTY_DRIVER_REAL_RAW;
 162
 163         tty_set_operations(serial_driver, &serial_ops);
 164         tty_port_link_device(&serial_port, serial_driver, 0);
 165
 166         if (tty_register_driver(serial_driver))
 167                 panic("Couldn't register serial driver\n");
 168         return 0;
 169 }
 170
 171
 172 static __exit void rs_exit(void)
 173 {
 174         tty_unregister_driver(serial_driver);
 175         put_tty_driver(serial_driver);
 176         tty_port_destroy(&serial_port);
 177 }
 178
 179
 180 /* We use `late_initcall' instead of just `__initcall' as a workaround for
 181  * the fact that (1) simcons_tty_init can't be called before tty_init,
 182  * (2) tty_init is called via `module_init', (3) if statically linked,
 183  * module_init == device_init, and (4) there's no ordering of init lists.
 184  * We can do this easily because simcons is always statically linked, but
 185  * other tty drivers that depend on tty_init and which must use
 186  * `module_init' to declare their init routines are likely to be broken.
 187  */
 188
 189 late_initcall(rs_init);
 190
 191
 192 #ifdef CONFIG_SERIAL_CONSOLE
 193
 194 static void iss_console_write(struct console *co, const char *s, unsigned count)
 195 {
 196         int len = strlen(s);
 197
 198         if (s != 0 && *s != 0)
 199                 simc_write(1, s, count < len ? count : len);
 200 }
 201
 202 static struct tty_driver* iss_console_device(struct console *c, int *index)
 203 {
 204         *index = c->index;
 205         return serial_driver;
 206 }
 207
 208
 209 static struct console sercons = {
 210         .name = "ttyS",
 211         .write = iss_console_write,
 212         .device = iss_console_device,
 213         .flags = CON_PRINTBUFFER,
 214         .index = -1
 215 };
 216
 217 static int __init iss_console_init(void)
 218 {
 219         register_console(&sercons);
 220         return 0;
 221 }
 222
 223 console_initcall(iss_console_init);
 224
 225 #endif /* CONFIG_SERIAL_CONSOLE */
 226