c865415838
The simcall asm macro assumes Windowed ABI parameter passing in registers, and doesn't work if its containing function gets inlined. This fix prevents that from happening. Signed-off-by: Marc Gauthier <marc@tensilica.com>
298 lines
6.8 KiB
C
298 lines
6.8 KiB
C
/*
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* arch/xtensa/platform-iss/console.c
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001-2005 Tensilica Inc.
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* Authors Christian Zankel, Joe Taylor
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/console.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/major.h>
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#include <linux/param.h>
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#include <linux/serial.h>
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#include <linux/serialP.h>
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#include <asm/uaccess.h>
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#include <asm/irq.h>
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#include <asm/platform/simcall.h>
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#include <linux/tty.h>
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#include <linux/tty_flip.h>
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#ifdef SERIAL_INLINE
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#define _INLINE_ inline
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#endif
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#define SERIAL_MAX_NUM_LINES 1
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#define SERIAL_TIMER_VALUE (20 * HZ)
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static struct tty_driver *serial_driver;
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static struct timer_list serial_timer;
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static DEFINE_SPINLOCK(timer_lock);
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int errno;
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static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__));
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static int __simc (int a, int b, int c, int d, int e, int f)
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{
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int ret;
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__asm__ __volatile__ ("simcall\n"
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"mov %0, a2\n"
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"mov %1, a3\n" : "=a" (ret), "=a" (errno)
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: : "a2", "a3");
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return ret;
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}
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static char *serial_version = "0.1";
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static char *serial_name = "ISS serial driver";
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/*
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* This routine is called whenever a serial port is opened. It
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* enables interrupts for a serial port, linking in its async structure into
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* the IRQ chain. It also performs the serial-specific
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* initialization for the tty structure.
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*/
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static void rs_poll(unsigned long);
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static int rs_open(struct tty_struct *tty, struct file * filp)
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{
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int line = tty->index;
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if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES))
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return -ENODEV;
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spin_lock(&timer_lock);
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if (tty->count == 1) {
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init_timer(&serial_timer);
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serial_timer.data = (unsigned long) tty;
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serial_timer.function = rs_poll;
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mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
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}
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spin_unlock(&timer_lock);
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return 0;
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}
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/*
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* ------------------------------------------------------------
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* iss_serial_close()
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*
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* This routine is called when the serial port gets closed. First, we
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* wait for the last remaining data to be sent. Then, we unlink its
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* async structure from the interrupt chain if necessary, and we free
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* that IRQ if nothing is left in the chain.
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* ------------------------------------------------------------
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*/
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static void rs_close(struct tty_struct *tty, struct file * filp)
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{
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spin_lock(&timer_lock);
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if (tty->count == 1)
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del_timer_sync(&serial_timer);
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spin_unlock(&timer_lock);
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}
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static int rs_write(struct tty_struct * tty,
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const unsigned char *buf, int count)
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{
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/* see drivers/char/serialX.c to reference original version */
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__simc (SYS_write, 1, (unsigned long)buf, count, 0, 0);
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return count;
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}
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static void rs_poll(unsigned long priv)
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{
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struct tty_struct* tty = (struct tty_struct*) priv;
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struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
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int i = 0;
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unsigned char c;
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spin_lock(&timer_lock);
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while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){
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__simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0);
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tty_insert_flip_char(tty, c, TTY_NORMAL);
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i++;
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}
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if (i)
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tty_flip_buffer_push(tty);
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mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
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spin_unlock(&timer_lock);
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}
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static void rs_put_char(struct tty_struct *tty, unsigned char ch)
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{
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char buf[2];
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if (!tty)
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return;
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buf[0] = ch;
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buf[1] = '\0'; /* Is this NULL necessary? */
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__simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0);
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}
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static void rs_flush_chars(struct tty_struct *tty)
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{
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}
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static int rs_write_room(struct tty_struct *tty)
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{
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/* Let's say iss can always accept 2K characters.. */
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return 2 * 1024;
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}
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static int rs_chars_in_buffer(struct tty_struct *tty)
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{
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/* the iss doesn't buffer characters */
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return 0;
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}
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static void rs_hangup(struct tty_struct *tty)
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{
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/* Stub, once again.. */
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}
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static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
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{
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/* Stub, once again.. */
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}
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static int rs_read_proc(char *page, char **start, off_t off, int count,
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int *eof, void *data)
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{
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int len = 0;
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off_t begin = 0;
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len += sprintf(page, "serinfo:1.0 driver:%s\n", serial_version);
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*eof = 1;
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if (off >= len + begin)
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return 0;
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*start = page + (off - begin);
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return ((count < begin + len - off) ? count : begin + len - off);
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}
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static struct tty_operations serial_ops = {
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.open = rs_open,
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.close = rs_close,
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.write = rs_write,
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.put_char = rs_put_char,
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.flush_chars = rs_flush_chars,
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.write_room = rs_write_room,
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.chars_in_buffer = rs_chars_in_buffer,
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.hangup = rs_hangup,
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.wait_until_sent = rs_wait_until_sent,
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.read_proc = rs_read_proc
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};
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int __init rs_init(void)
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{
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serial_driver = alloc_tty_driver(1);
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printk ("%s %s\n", serial_name, serial_version);
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/* Initialize the tty_driver structure */
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serial_driver->owner = THIS_MODULE;
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serial_driver->driver_name = "iss_serial";
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serial_driver->name = "ttyS";
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serial_driver->major = TTY_MAJOR;
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serial_driver->minor_start = 64;
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serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
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serial_driver->subtype = SERIAL_TYPE_NORMAL;
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serial_driver->init_termios = tty_std_termios;
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serial_driver->init_termios.c_cflag =
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B9600 | CS8 | CREAD | HUPCL | CLOCAL;
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serial_driver->flags = TTY_DRIVER_REAL_RAW;
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tty_set_operations(serial_driver, &serial_ops);
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if (tty_register_driver(serial_driver))
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panic("Couldn't register serial driver\n");
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return 0;
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}
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static __exit void rs_exit(void)
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{
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int error;
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if ((error = tty_unregister_driver(serial_driver)))
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printk("ISS_SERIAL: failed to unregister serial driver (%d)\n",
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error);
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put_tty_driver(serial_driver);
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}
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/* We use `late_initcall' instead of just `__initcall' as a workaround for
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* the fact that (1) simcons_tty_init can't be called before tty_init,
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* (2) tty_init is called via `module_init', (3) if statically linked,
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* module_init == device_init, and (4) there's no ordering of init lists.
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* We can do this easily because simcons is always statically linked, but
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* other tty drivers that depend on tty_init and which must use
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* `module_init' to declare their init routines are likely to be broken.
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*/
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late_initcall(rs_init);
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#ifdef CONFIG_SERIAL_CONSOLE
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static void iss_console_write(struct console *co, const char *s, unsigned count)
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{
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int len = strlen(s);
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if (s != 0 && *s != 0)
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__simc (SYS_write, 1, (unsigned long)s,
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count < len ? count : len,0,0);
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}
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static struct tty_driver* iss_console_device(struct console *c, int *index)
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{
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*index = c->index;
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return serial_driver;
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}
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static struct console sercons = {
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.name = "ttyS",
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.write = iss_console_write,
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.device = iss_console_device,
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.flags = CON_PRINTBUFFER,
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.index = -1
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};
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static int __init iss_console_init(void)
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{
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register_console(&sercons);
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return 0;
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}
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console_initcall(iss_console_init);
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#endif /* CONFIG_SERIAL_CONSOLE */
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