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