[thirdparty/kernel/linux.git] / arch / ia64 / hp / sim / simserial.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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).
 *
 * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
 *	Stephane Eranian <eranian@hpl.hp.com>
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 */

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/capability.h>
#include <linux/circ_buf.h>
#include <linux/console.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/uaccess.h>

#include <asm/hpsim.h>

#include "hpsim_ssc.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 */

struct serial_state {
	struct tty_port port;
	struct circ_buf xmit;
	int irq;
	int x_char;
};

static struct serial_state rs_table[NR_PORTS];

struct tty_driver *hp_simserial_driver;

static struct console *console;

static void receive_chars(struct tty_port *port)
{
	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);
			}
#endif
			seen_esc = 0;
			continue;
		}
		seen_esc = 0;

		if (tty_insert_flip_char(port, ch, TTY_NORMAL) == 0)
			break;
	}
	tty_flip_buffer_push(port);
}

/*
 * This is the serial driver's interrupt routine for a single port
 */
static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
{
	struct serial_state *info = dev_id;

	receive_chars(&info->port);

	return IRQ_HANDLED;
}

/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */

static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	if (!info->xmit.buf)
		return 0;

	local_irq_save(flags);
	if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
		local_irq_restore(flags);
		return 0;
	}
	info->xmit.buf[info->xmit.head] = ch;
	info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
	local_irq_restore(flags);
	return 1;
}

static void transmit_chars(struct tty_struct *tty, struct serial_state *info,
		int *intr_done)
{
	int count;
	unsigned long flags;

	local_irq_save(flags);

	if (info->x_char) {
		char c = info->x_char;

		console->write(console, &c, 1);

		info->x_char = 0;

		goto out;
	}

	if (info->xmit.head == info->xmit.tail || tty->stopped) {
#ifdef SIMSERIAL_DEBUG
		printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
		       info->xmit.head, info->xmit.tail, tty->stopped);
#endif
		goto out;
	}
	/*
	 * We removed the loop and try to do it in to chunks. We need
	 * 2 operations maximum because it's a ring buffer.
	 *
	 * First from current to tail if possible.
	 * Then from the beginning of the buffer until necessary
	 */

	count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
		    SERIAL_XMIT_SIZE - info->xmit.tail);
	console->write(console, info->xmit.buf+info->xmit.tail, count);

	info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);

	/*
	 * We have more at the beginning of the buffer
	 */
	count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
	if (count) {
		console->write(console, info->xmit.buf, count);
		info->xmit.tail += count;
	}
out:
	local_irq_restore(flags);
}

static void rs_flush_chars(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	if (info->xmit.head == info->xmit.tail || tty->stopped ||
			!info->xmit.buf)
		return;

	transmit_chars(tty, info, NULL);
}

static int rs_write(struct tty_struct * tty,
		    const unsigned char *buf, int count)
{
	struct serial_state *info = tty->driver_data;
	int	c, ret = 0;
	unsigned long flags;

	if (!info->xmit.buf)
		return 0;

	local_irq_save(flags);
	while (1) {
		c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
		if (count < c)
			c = count;
		if (c <= 0) {
			break;
		}
		memcpy(info->xmit.buf + info->xmit.head, buf, c);
		info->xmit.head = ((info->xmit.head + c) &
				   (SERIAL_XMIT_SIZE-1));
		buf += c;
		count -= c;
		ret += c;
	}
	local_irq_restore(flags);
	/*
	 * Hey, we transmit directly from here in our case
	 */
	if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) &&
			!tty->stopped)
		transmit_chars(tty, info, NULL);

	return ret;
}

static int rs_write_room(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static int rs_chars_in_buffer(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}

static void rs_flush_buffer(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;
	unsigned long flags;

	local_irq_save(flags);
	info->xmit.head = info->xmit.tail = 0;
	local_irq_restore(flags);

	tty_wakeup(tty);
}

/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
	struct serial_state *info = tty->driver_data;

	info->x_char = ch;
	if (ch) {
		/*
		 * I guess we could call console->write() directly but
		 * let's do that for now.
		 */
		transmit_chars(tty, info, NULL);
	}
}

/*
 * ------------------------------------------------------------
 * rs_throttle()
 *
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
	if (I_IXOFF(tty))
		rs_send_xchar(tty, STOP_CHAR(tty));

	printk(KERN_INFO "simrs_throttle called\n");
}

static void rs_unthrottle(struct tty_struct * tty)
{
	struct serial_state *info = tty->driver_data;

	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			rs_send_xchar(tty, START_CHAR(tty));
	}
	printk(KERN_INFO "simrs_unthrottle called\n");
}

static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
{
	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
	    (cmd != TIOCMIWAIT)) {
		if (tty_io_error(tty))
		    return -EIO;
	}

	switch (cmd) {
	case TIOCGSERIAL:
	case TIOCSSERIAL:
	case TIOCSERGSTRUCT:
	case TIOCMIWAIT:
		return 0;
	case TIOCSERCONFIG:
	case TIOCSERGETLSR: /* Get line status register */
		return -EINVAL;
	case TIOCSERGWILD:
	case TIOCSERSWILD:
		/* "setserial -W" is called in Debian boot */
		printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
		return 0;
	}
	return -ENOIOCTLCMD;
}

#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

/*
 * This routine will shutdown a serial port; interrupts are disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void shutdown(struct tty_port *port)
{
	struct serial_state *info = container_of(port, struct serial_state,
			port);
	unsigned long flags;

	local_irq_save(flags);
	if (info->irq)
		free_irq(info->irq, info);

	if (info->xmit.buf) {
		free_page((unsigned long) info->xmit.buf);
		info->xmit.buf = NULL;
	}
	local_irq_restore(flags);
}

static void rs_close(struct tty_struct *tty, struct file * filp)
{
	struct serial_state *info = tty->driver_data;

	tty_port_close(&info->port, tty, filp);
}

static void rs_hangup(struct tty_struct *tty)
{
	struct serial_state *info = tty->driver_data;

	rs_flush_buffer(tty);
	tty_port_hangup(&info->port);
}

static int activate(struct tty_port *port, struct tty_struct *tty)
{
	struct serial_state *state = container_of(port, struct serial_state,
			port);
	unsigned long flags, page;
	int retval = 0;

	page = get_zeroed_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	local_irq_save(flags);

	if (state->xmit.buf)
		free_page(page);
	else
		state->xmit.buf = (unsigned char *) page;

	if (state->irq) {
		retval = request_irq(state->irq, rs_interrupt_single, 0,
				"simserial", state);
		if (retval)
			goto errout;
	}

	state->xmit.head = state->xmit.tail = 0;
errout:
	local_irq_restore(flags);
	return retval;
}


/*
 * 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 int rs_open(struct tty_struct *tty, struct file * filp)
{
	struct serial_state *info = rs_table + tty->index;
	struct tty_port *port = &info->port;

	tty->driver_data = info;
	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

	/*
	 * figure out which console to use (should be one already)
	 */
	console = console_drivers;
	while (console) {
		if ((console->flags & CON_ENABLED) && console->write) break;
		console = console->next;
	}

	return tty_port_open(port, tty, filp);
}

/*
 * /proc fs routines....
 */

static int rs_proc_show(struct seq_file *m, void *v)
{
	int i;

	seq_printf(m, "simserinfo:1.0\n");
	for (i = 0; i < NR_PORTS; i++)
		seq_printf(m, "%d: uart:16550 port:3F8 irq:%d\n",
		       i, rs_table[i].irq);
	return 0;
}

static int rs_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, rs_proc_show, NULL);
}

static const struct file_operations rs_proc_fops = {
	.owner		= THIS_MODULE,
	.open		= rs_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct tty_operations hp_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,
	.flush_buffer = rs_flush_buffer,
	.ioctl = rs_ioctl,
	.throttle = rs_throttle,
	.unthrottle = rs_unthrottle,
	.send_xchar = rs_send_xchar,
	.hangup = rs_hangup,
	.proc_fops = &rs_proc_fops,
};

static const struct tty_port_operations hp_port_ops = {
	.activate = activate,
	.shutdown = shutdown,
};

static int __init simrs_init(void)
{
	struct serial_state *state;
	int retval;

	if (!ia64_platform_is("hpsim"))
		return -ENODEV;

	hp_simserial_driver = alloc_tty_driver(NR_PORTS);
	if (!hp_simserial_driver)
		return -ENOMEM;

	printk(KERN_INFO "SimSerial driver with no serial options enabled\n");

	/* Initialize the tty_driver structure */

	hp_simserial_driver->driver_name = "simserial";
	hp_simserial_driver->name = "ttyS";
	hp_simserial_driver->major = TTY_MAJOR;
	hp_simserial_driver->minor_start = 64;
	hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
	hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
	hp_simserial_driver->init_termios = tty_std_termios;
	hp_simserial_driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
	tty_set_operations(hp_simserial_driver, &hp_ops);

	state = rs_table;
	tty_port_init(&state->port);
	state->port.ops = &hp_port_ops;
	state->port.close_delay = 0; /* XXX really 0? */

	retval = hpsim_get_irq(KEYBOARD_INTR);
	if (retval < 0) {
		printk(KERN_ERR "%s: out of interrupt vectors!\n",
				__func__);
		goto err_free_tty;
	}

	state->irq = retval;

	/* the port is imaginary */
	printk(KERN_INFO "ttyS0 at 0x03f8 (irq = %d) is a 16550\n", state->irq);

	tty_port_link_device(&state->port, hp_simserial_driver, 0);
	retval = tty_register_driver(hp_simserial_driver);
	if (retval) {
		printk(KERN_ERR "Couldn't register simserial driver\n");
		goto err_free_tty;
	}

	return 0;
err_free_tty:
	put_tty_driver(hp_simserial_driver);
	tty_port_destroy(&state->port);
	return retval;
}

#ifndef MODULE
__initcall(simrs_init);
#endif
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* Simulated Serial Driver (fake serial)
	4	*
	5	* This driver is mostly used for bringup purposes and will go away.
	6	* It has a strong dependency on the system console. All outputs
	7	* are rerouted to the same facility as the one used by printk which, in our
adb636fe	8	* case means sys_sim.c console (goes via the simulator).
1da177e4 LT	9	*
	10	* Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
	11	* Stephane Eranian <eranian@hpl.hp.com>
	12	* David Mosberger-Tang <davidm@hpl.hp.com>
1da177e4 LT	13	*/
1da177e4 LT	14
1da177e4 LT	15	#include <linux/init.h>
	16	#include <linux/errno.h>
	17	#include <linux/sched.h>
b17b0153	18	#include <linux/sched/debug.h>
1da177e4 LT	19	#include <linux/tty.h>
	20	#include <linux/tty_flip.h>
	21	#include <linux/major.h>
	22	#include <linux/fcntl.h>
	23	#include <linux/mm.h>
bf54215e	24	#include <linux/seq_file.h>
1da177e4	25	#include <linux/slab.h>
a9415644	26	#include <linux/capability.h>
3c4782dc	27	#include <linux/circ_buf.h>
1da177e4	28	#include <linux/console.h>
8b916330	29	#include <linux/irq.h>
1da177e4 LT	30	#include <linux/module.h>
1da177e4 LT	31	#include <linux/serial.h>
819c67e6	32	#include <linux/sysrq.h>
8b916330	33	#include <linux/uaccess.h>
1da177e4	34
035cfe5a	35	#include <asm/hpsim.h>
1da177e4	36
035cfe5a JS	37	#include "hpsim_ssc.h"
035cfe5a JS	38
1da177e4 LT	39	#undef SIMSERIAL_DEBUG /* define this to get some debug information */
	40
	41	#define KEYBOARD_INTR 3 /* must match with simulator! */
	42
	43	#define NR_PORTS 1 /* only one port for now */
1da177e4	44
3c4782dc	45	struct serial_state {
7f32f8dd	46	struct tty_port port;
3c4782dc JS	47	struct circ_buf xmit;
	48	int irq;
	49	int x_char;
	50	};
	51
fd2d7a6e	52	static struct serial_state rs_table[NR_PORTS];
1da177e4 LT	53
	54	struct tty_driver *hp_simserial_driver;
	55
1da177e4 LT	56	static struct console *console;
1da177e4 LT	57
2e124b4a	58	static void receive_chars(struct tty_port *port)
1da177e4 LT	59	{
	60	unsigned char ch;
	61	static unsigned char seen_esc = 0;
	62
	63	while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
f66279cd	64	if (ch == 27 && seen_esc == 0) {
1da177e4 LT	65	seen_esc = 1;
1da177e4 LT	66	continue;
f66279cd JS	67	} else if (seen_esc == 1 && ch == 'O') {
	68	seen_esc = 2;
	69	continue;
	70	} else if (seen_esc == 2) {
	71	if (ch == 'P') /* F1 */
	72	show_state();
819c67e6	73	#ifdef CONFIG_MAGIC_SYSRQ
f66279cd JS	74	if (ch == 'S') { /* F4 */
	75	do {
	76	ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR);
	77	} while (!ch);
	78	handle_sysrq(ch);
1da177e4	79	}
f66279cd JS	80	#endif
	81	seen_esc = 0;
	82	continue;
1da177e4 LT	83	}
1da177e4 LT	84	seen_esc = 0;
1da177e4	85
92a19f9c	86	if (tty_insert_flip_char(port, ch, TTY_NORMAL) == 0)
d50f5c5c	87	break;
1da177e4	88	}
2e124b4a	89	tty_flip_buffer_push(port);
1da177e4 LT	90	}
	91
	92	/*
	93	* This is the serial driver's interrupt routine for a single port
	94	*/
5dcded1b	95	static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
1da177e4	96	{
916b7656	97	struct serial_state *info = dev_id;
1da177e4	98
2e124b4a JS	99	receive_chars(&info->port);
2e124b4a JS	100
1da177e4 LT	101	return IRQ_HANDLED;
	102	}
	103
	104	/*
	105	* -------------------------------------------------------------------
	106	* Here ends the serial interrupt routines.
	107	* -------------------------------------------------------------------
	108	*/
	109
f34d7a5b	110	static int rs_put_char(struct tty_struct *tty, unsigned char ch)
1da177e4	111	{
916b7656	112	struct serial_state *info = tty->driver_data;
1da177e4 LT	113	unsigned long flags;
1da177e4 LT	114
6e9ebcfa	115	if (!info->xmit.buf)
f34d7a5b	116	return 0;
1da177e4 LT	117
	118	local_irq_save(flags);
	119	if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
	120	local_irq_restore(flags);
f34d7a5b	121	return 0;
1da177e4 LT	122	}
	123	info->xmit.buf[info->xmit.head] = ch;
	124	info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
	125	local_irq_restore(flags);
f34d7a5b	126	return 1;
1da177e4 LT	127	}
1da177e4 LT	128
5e99d545 JS	129	static void transmit_chars(struct tty_struct tty, struct serial_state info,
5e99d545 JS	130	int *intr_done)
1da177e4 LT	131	{
	132	int count;
	133	unsigned long flags;
	134
1da177e4 LT	135	local_irq_save(flags);
	136
	137	if (info->x_char) {
	138	char c = info->x_char;
	139
	140	console->write(console, &c, 1);
	141
1da177e4 LT	142	info->x_char = 0;
	143
	144	goto out;
	145	}
	146
ee797069	147	if (info->xmit.head == info->xmit.tail \|\| tty->stopped) {
1da177e4 LT	148	#ifdef SIMSERIAL_DEBUG
1da177e4 LT	149	printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
5e99d545	150	info->xmit.head, info->xmit.tail, tty->stopped);
1da177e4 LT	151	#endif
	152	goto out;
	153	}
	154	/*
	155	* We removed the loop and try to do it in to chunks. We need
	156	* 2 operations maximum because it's a ring buffer.
	157	*
	158	* First from current to tail if possible.
	159	* Then from the beginning of the buffer until necessary
	160	*/
	161
	162	count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
	163	SERIAL_XMIT_SIZE - info->xmit.tail);
	164	console->write(console, info->xmit.buf+info->xmit.tail, count);
	165
	166	info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);
	167
	168	/*
	169	* We have more at the beginning of the buffer
	170	*/
	171	count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
	172	if (count) {
	173	console->write(console, info->xmit.buf, count);
	174	info->xmit.tail += count;
	175	}
	176	out:
	177	local_irq_restore(flags);
	178	}
	179
	180	static void rs_flush_chars(struct tty_struct *tty)
	181	{
916b7656	182	struct serial_state *info = tty->driver_data;
1da177e4	183
f66279cd	184	if (info->xmit.head == info->xmit.tail \|\| tty->stopped \|\|
ee797069	185	!info->xmit.buf)
1da177e4 LT	186	return;
1da177e4 LT	187
5e99d545	188	transmit_chars(tty, info, NULL);
1da177e4 LT	189	}
1da177e4 LT	190
1da177e4 LT	191	static int rs_write(struct tty_struct * tty,
	192	const unsigned char *buf, int count)
	193	{
916b7656	194	struct serial_state *info = tty->driver_data;
1da177e4	195	int c, ret = 0;
1da177e4 LT	196	unsigned long flags;
1da177e4 LT	197
6e9ebcfa	198	if (!info->xmit.buf)
d88405d4	199	return 0;
1da177e4 LT	200
	201	local_irq_save(flags);
	202	while (1) {
	203	c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
	204	if (count < c)
	205	c = count;
	206	if (c <= 0) {
	207	break;
	208	}
	209	memcpy(info->xmit.buf + info->xmit.head, buf, c);
	210	info->xmit.head = ((info->xmit.head + c) &
	211	(SERIAL_XMIT_SIZE-1));
	212	buf += c;
	213	count -= c;
	214	ret += c;
	215	}
	216	local_irq_restore(flags);
	217	/*
	218	* Hey, we transmit directly from here in our case
	219	*/
f66279cd	220	if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) &&
ee797069	221	!tty->stopped)
5e99d545	222	transmit_chars(tty, info, NULL);
f66279cd	223
1da177e4 LT	224	return ret;
	225	}
	226
	227	static int rs_write_room(struct tty_struct *tty)
	228	{
916b7656	229	struct serial_state *info = tty->driver_data;
1da177e4 LT	230
	231	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
	232	}
	233
	234	static int rs_chars_in_buffer(struct tty_struct *tty)
	235	{
916b7656	236	struct serial_state *info = tty->driver_data;
1da177e4 LT	237
	238	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
	239	}
	240
	241	static void rs_flush_buffer(struct tty_struct *tty)
	242	{
916b7656	243	struct serial_state *info = tty->driver_data;
1da177e4 LT	244	unsigned long flags;
	245
	246	local_irq_save(flags);
	247	info->xmit.head = info->xmit.tail = 0;
	248	local_irq_restore(flags);
	249
15648f15	250	tty_wakeup(tty);
1da177e4 LT	251	}
	252
	253	/*
	254	* This function is used to send a high-priority XON/XOFF character to
	255	* the device
	256	*/
	257	static void rs_send_xchar(struct tty_struct *tty, char ch)
	258	{
916b7656	259	struct serial_state *info = tty->driver_data;
1da177e4 LT	260
	261	info->x_char = ch;
	262	if (ch) {
	263	/*
	264	* I guess we could call console->write() directly but
	265	* let's do that for now.
	266	*/
5e99d545	267	transmit_chars(tty, info, NULL);
1da177e4 LT	268	}
	269	}
	270
	271	/*
	272	* ------------------------------------------------------------
	273	* rs_throttle()
	274	*
	275	* This routine is called by the upper-layer tty layer to signal that
	276	* incoming characters should be throttled.
	277	* ------------------------------------------------------------
	278	*/
	279	static void rs_throttle(struct tty_struct * tty)
	280	{
f66279cd JS	281	if (I_IXOFF(tty))
f66279cd JS	282	rs_send_xchar(tty, STOP_CHAR(tty));
1da177e4 LT	283
	284	printk(KERN_INFO "simrs_throttle called\n");
	285	}
	286
	287	static void rs_unthrottle(struct tty_struct * tty)
	288	{
916b7656	289	struct serial_state *info = tty->driver_data;
1da177e4 LT	290
	291	if (I_IXOFF(tty)) {
	292	if (info->x_char)
	293	info->x_char = 0;
	294	else
	295	rs_send_xchar(tty, START_CHAR(tty));
	296	}
	297	printk(KERN_INFO "simrs_unthrottle called\n");
	298	}
	299
10e82f6c	300	static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1da177e4 LT	301	{
	302	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	303	(cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
0587102c	304	(cmd != TIOCMIWAIT)) {
18900ca6	305	if (tty_io_error(tty))
1da177e4 LT	306	return -EIO;
	307	}
	308
	309	switch (cmd) {
f66279cd JS	310	case TIOCGSERIAL:
	311	case TIOCSSERIAL:
	312	case TIOCSERGSTRUCT:
	313	case TIOCMIWAIT:
	314	return 0;
	315	case TIOCSERCONFIG:
	316	case TIOCSERGETLSR: /* Get line status register */
	317	return -EINVAL;
	318	case TIOCSERGWILD:
	319	case TIOCSERSWILD:
	320	/* "setserial -W" is called in Debian boot */
	321	printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
	322	return 0;
	323	}
	324	return -ENOIOCTLCMD;
1da177e4 LT	325	}
	326
	327	#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK\|BRKINT\|IGNPAR\|PARMRK\|INPCK))
	328
1da177e4 LT	329	/*
	330	* This routine will shutdown a serial port; interrupts are disabled, and
	331	* DTR is dropped if the hangup on close termio flag is on.
	332	*/
458cd31a	333	static void shutdown(struct tty_port *port)
1da177e4	334	{
458cd31a JS	335	struct serial_state *info = container_of(port, struct serial_state,
	336	port);
	337	unsigned long flags;
1da177e4 LT	338
1da177e4 LT	339	local_irq_save(flags);
f66279cd JS	340	if (info->irq)
f66279cd JS	341	free_irq(info->irq, info);
1da177e4	342
f66279cd JS	343	if (info->xmit.buf) {
	344	free_page((unsigned long) info->xmit.buf);
	345	info->xmit.buf = NULL;
1da177e4 LT	346	}
	347	local_irq_restore(flags);
	348	}
	349
1da177e4 LT	350	static void rs_close(struct tty_struct tty, struct file filp)
1da177e4 LT	351	{
916b7656	352	struct serial_state *info = tty->driver_data;
37343030	353
458cd31a	354	tty_port_close(&info->port, tty, filp);
1da177e4 LT	355	}
1da177e4 LT	356
1da177e4 LT	357	static void rs_hangup(struct tty_struct *tty)
1da177e4 LT	358	{
916b7656	359	struct serial_state *info = tty->driver_data;
1da177e4	360
1da177e4	361	rs_flush_buffer(tty);
458cd31a	362	tty_port_hangup(&info->port);
1da177e4 LT	363	}
1da177e4 LT	364
9aead90a	365	static int activate(struct tty_port port, struct tty_struct tty)
1da177e4	366	{
9aead90a JS	367	struct serial_state *state = container_of(port, struct serial_state,
9aead90a JS	368	port);
f66279cd JS	369	unsigned long flags, page;
f66279cd JS	370	int retval = 0;
1da177e4 LT	371
	372	page = get_zeroed_page(GFP_KERNEL);
	373	if (!page)
	374	return -ENOMEM;
	375
	376	local_irq_save(flags);
	377
916b7656	378	if (state->xmit.buf)
1da177e4 LT	379	free_page(page);
1da177e4 LT	380	else
916b7656	381	state->xmit.buf = (unsigned char *) page;
1da177e4	382
964105b5	383	if (state->irq) {
2f8c521a	384	retval = request_irq(state->irq, rs_interrupt_single, 0,
916b7656	385	"simserial", state);
9e12dd5f	386	if (retval)
1da177e4	387	goto errout;
1da177e4 LT	388	}
1da177e4 LT	389
916b7656	390	state->xmit.head = state->xmit.tail = 0;
1da177e4 LT	391	errout:
	392	local_irq_restore(flags);
	393	return retval;
	394	}
	395
	396
	397	/*
	398	* This routine is called whenever a serial port is opened. It
	399	* enables interrupts for a serial port, linking in its async structure into
	400	* the IRQ chain. It also performs the serial-specific
	401	* initialization for the tty structure.
	402	*/
	403	static int rs_open(struct tty_struct tty, struct file filp)
	404	{
916b7656	405	struct serial_state *info = rs_table + tty->index;
7f32f8dd	406	struct tty_port *port = &info->port;
1da177e4	407
916b7656	408	tty->driver_data = info;
d6c53c0e	409	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1da177e4	410
1da177e4 LT	411	/*
	412	* figure out which console to use (should be one already)
	413	*/
	414	console = console_drivers;
	415	while (console) {
	416	if ((console->flags & CON_ENABLED) && console->write) break;
	417	console = console->next;
	418	}
	419
9aead90a	420	return tty_port_open(port, tty, filp);
1da177e4 LT	421	}
	422
	423	/*
	424	* /proc fs routines....
	425	*/
	426
bf54215e	427	static int rs_proc_show(struct seq_file m, void v)
1da177e4	428	{
bf54215e AD	429	int i;
bf54215e AD	430
6e9ebcfa	431	seq_printf(m, "simserinfo:1.0\n");
bf54215e	432	for (i = 0; i < NR_PORTS; i++)
98e3a9e6 JS	433	seq_printf(m, "%d: uart:16550 port:3F8 irq:%d\n",
98e3a9e6 JS	434	i, rs_table[i].irq);
bf54215e	435	return 0;
1da177e4 LT	436	}
1da177e4 LT	437
bf54215e AD	438	static int rs_proc_open(struct inode inode, struct file file)
	439	{
	440	return single_open(file, rs_proc_show, NULL);
	441	}
	442
	443	static const struct file_operations rs_proc_fops = {
	444	.owner = THIS_MODULE,
	445	.open = rs_proc_open,
	446	.read = seq_read,
	447	.llseek = seq_lseek,
	448	.release = single_release,
	449	};
	450
b68e31d0	451	static const struct tty_operations hp_ops = {
1da177e4 LT	452	.open = rs_open,
	453	.close = rs_close,
	454	.write = rs_write,
	455	.put_char = rs_put_char,
	456	.flush_chars = rs_flush_chars,
	457	.write_room = rs_write_room,
	458	.chars_in_buffer = rs_chars_in_buffer,
	459	.flush_buffer = rs_flush_buffer,
	460	.ioctl = rs_ioctl,
	461	.throttle = rs_throttle,
	462	.unthrottle = rs_unthrottle,
	463	.send_xchar = rs_send_xchar,
1da177e4	464	.hangup = rs_hangup,
bf54215e	465	.proc_fops = &rs_proc_fops,
1da177e4 LT	466	};
1da177e4 LT	467
37343030	468	static const struct tty_port_operations hp_port_ops = {
9aead90a	469	.activate = activate,
458cd31a	470	.shutdown = shutdown,
37343030 JS	471	};
37343030 JS	472
fd2d7a6e	473	static int __init simrs_init(void)
1da177e4	474	{
fd2d7a6e JS	475	struct serial_state *state;
fd2d7a6e JS	476	int retval;
1da177e4 LT	477
	478	if (!ia64_platform_is("hpsim"))
	479	return -ENODEV;
	480
410235fd	481	hp_simserial_driver = alloc_tty_driver(NR_PORTS);
1da177e4 LT	482	if (!hp_simserial_driver)
	483	return -ENOMEM;
	484
6e9ebcfa	485	printk(KERN_INFO "SimSerial driver with no serial options enabled\n");
1da177e4 LT	486
	487	/* Initialize the tty_driver structure */
	488
1da177e4 LT	489	hp_simserial_driver->driver_name = "simserial";
	490	hp_simserial_driver->name = "ttyS";
	491	hp_simserial_driver->major = TTY_MAJOR;
	492	hp_simserial_driver->minor_start = 64;
	493	hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
	494	hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
	495	hp_simserial_driver->init_termios = tty_std_termios;
	496	hp_simserial_driver->init_termios.c_cflag =
	497	B9600 \| CS8 \| CREAD \| HUPCL \| CLOCAL;
	498	hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
	499	tty_set_operations(hp_simserial_driver, &hp_ops);
	500
fd2d7a6e	501	state = rs_table;
7f32f8dd	502	tty_port_init(&state->port);
37343030	503	state->port.ops = &hp_port_ops;
7f32f8dd	504	state->port.close_delay = 0; /* XXX really 0? */
fd2d7a6e JS	505
	506	retval = hpsim_get_irq(KEYBOARD_INTR);
	507	if (retval < 0) {
	508	printk(KERN_ERR "%s: out of interrupt vectors!\n",
	509	__func__);
	510	goto err_free_tty;
	511	}
1da177e4	512
fd2d7a6e	513	state->irq = retval;
1da177e4	514
fd2d7a6e	515	/* the port is imaginary */
98e3a9e6	516	printk(KERN_INFO "ttyS0 at 0x03f8 (irq = %d) is a 16550\n", state->irq);
1da177e4	517
b19e2ca7	518	tty_port_link_device(&state->port, hp_simserial_driver, 0);
fd2d7a6e JS	519	retval = tty_register_driver(hp_simserial_driver);
	520	if (retval) {
	521	printk(KERN_ERR "Couldn't register simserial driver\n");
	522	goto err_free_tty;
1da177e4 LT	523	}
1da177e4 LT	524
1da177e4	525	return 0;
fd2d7a6e JS	526	err_free_tty:
fd2d7a6e JS	527	put_tty_driver(hp_simserial_driver);
191c5f10	528	tty_port_destroy(&state->port);
fd2d7a6e	529	return retval;
1da177e4 LT	530	}
	531
	532	#ifndef MODULE
	533	__initcall(simrs_init);
	534	#endif