path: root/arch/ia64/hp/sim/simserial.c

/*
 * Simulated Serial Driver (fake serial)
 *
 * This driver is mostly used for bringup purposes and will go away.
 * It has a strong dependency on the system console. All outputs
 * are rerouted to the same facility as the one used by printk which, in our
 * case means sys_sim.c console (goes via the simulator). The code hereafter
 * is completely leveraged from the serial.c driver.
 *
 * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * 02/04/00 D. Mosberger	Merged in serial.c bug fixes in rs_close().
 * 02/25/00 D. Mosberger	Synced up with 2.3.99pre-5 version of serial.c.
 * 07/30/02 D. Mosberger	Replace sti()/cli() with explicit spinlocks & local irq masking
 */

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/capability.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/sysrq.h>

#include <asm/irq.h>
#include <asm/hw_irq.h>
#include <asm/uaccess.h>

#undef SIMSERIAL_DEBUG	/* define this to get some debug information */

#define KEYBOARD_INTR	3	/* must match with simulator! */

#define NR_PORTS	1	/* only one port for now */

#define IRQ_T(info) ((info->flags & ASYNC_SHARE_IRQ) ? IRQF_SHARED : IRQF_DISABLED)

#define SSC_GETCHAR	21

extern long ia64_ssc (long, long, long, long, int);
extern void ia64_ssc_connect_irq (long intr, long irq);

static char *serial_name = "SimSerial driver";
static char *serial_version = "0.6";

/*
 * This has been extracted from asm/serial.h. We need one eventually but
 * I don't know exactly what we're going to put in it so just fake one
 * for now.
 */
#define BASE_BAUD ( 1843200 / 16 )

#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)

/*
 * Most of the values here are meaningless to this particular driver.
 * However some values must be preserved for the code (leveraged from serial.c
 * to work correctly).
 * port must not be 0
 * type must not be UNKNOWN
 * So I picked arbitrary (guess from where?) values instead
 */
static struct serial_state rs_table[NR_PORTS]={
  /* UART CLK   PORT IRQ     FLAGS        */
  { 0, BASE_BAUD, 0x3F8, 0, STD_COM_FLAGS,0,PORT_16550 }  /* ttyS0 */
};

/*
 * Just for the fun of it !
 */
static struct serial_uart_config uart_config[] = {
	{ "unknown", 1, 0 },
	{ "8250", 1, 0 },
	{ "16450", 1, 0 },
	{ "16550", 1, 0 },
	{ "16550A", 16, UART_CLEAR_FIFO | UART_USE_FIFO },
	{ "cirrus", 1, 0 },
	{ "ST16650", 1, UART_CLEAR_FIFO | UART_STARTECH },
	{ "ST16650V2", 32, UART_CLEAR_FIFO | UART_USE_FIFO |
		  UART_STARTECH },
	{ "TI16750", 64, UART_CLEAR_FIFO | UART_USE_FIFO},
	{ NULL, 0}
};

struct tty_driver *hp_simserial_driver;

static struct async_struct *IRQ_ports[NR_IRQS];

static struct console *console;

static unsigned char *tmp_buf;

extern struct console *console_drivers; /* from kernel/printk.c */

/*
 * ------------------------------------------------------------
 * rs_stop() and rs_start()
 *
 * This routines are called before setting or resetting tty->stopped.
 * They enable or disable transmitter interrupts, as necessary.
 * ------------------------------------------------------------
 */
static void rs_stop(struct tty_struct *tty)
{
#ifdef SIMSERIAL_DEBUG
	printk("rs_stop: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
		tty->stopped, tty->hw_stopped, tty->flow_stopped);
#endif

}

static void rs_start(struct tty_struct *tty)
{
#ifdef SIMSERIAL_DEBUG
	printk("rs_start: tty->stopped=%d tty->hw_stopped=%d tty->flow_stopped=%d\n",
		tty->stopped, tty->hw_stopped, tty->flow_stopped);
#endif
}

static  void receive_chars(struct tty_struct *tty)
{
	unsigned char ch;
	static unsigned char seen_esc = 0;

	while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
		if ( ch == 27 && seen_esc == 0 ) {
			seen_esc = 1;
			continue;
		} else {
			if ( seen_esc==1 && ch == 'O' ) {
				seen_esc = 2;
				continue;
			} else if ( seen_esc == 2 ) {
				if ( ch == 'P' ) /* F1 */
					show_state();
#ifdef CONFIG_MAGIC_SYSRQ
				if ( ch == 'S' ) { /* F4 */
					do
						ch = ia64_ssc(0, 0, 0, 0,
							      SSC_GETCHAR);
					while (!ch);
					handle_sysrq(ch, NULL);
				}
#endif
				seen_esc = 0;
				continue;
			}
		}
		seen_esc = 0;

		if (tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0)
			break;