Initial import

1 files changed, 1918 insertions, 0 deletions

diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
new file mode 100644
index 000000000..e91b89dc6
--- /dev/null
+++ b/drivers/s390/char/tty3270.c
@@ -0,0 +1,1918 @@
+/*
+ *    IBM/3270 Driver - tty functions.
+ *
+ *  Author(s):
+ *    Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
+ *    Rewritten for 2.5 by Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *	-- Copyright IBM Corp. 2003
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kdev_t.h>
+#include <linux/tty.h>
+#include <linux/vt_kern.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+
+#include <linux/slab.h>
+#include <linux/bootmem.h>
+#include <linux/compat.h>
+
+#include <asm/ccwdev.h>
+#include <asm/cio.h>
+#include <asm/ebcdic.h>
+#include <asm/uaccess.h>
+
+#include "raw3270.h"
+#include "tty3270.h"
+#include "keyboard.h"
+
+#define TTY3270_CHAR_BUF_SIZE 256
+#define TTY3270_OUTPUT_BUFFER_SIZE 1024
+#define TTY3270_STRING_PAGES 5
+
+struct tty_driver *tty3270_driver;
+static int tty3270_max_index;
+
+static struct raw3270_fn tty3270_fn;
+
+struct tty3270_cell {
+	unsigned char character;
+	unsigned char highlight;
+	unsigned char f_color;
+};
+
+struct tty3270_line {
+	struct tty3270_cell *cells;
+	int len;
+};
+
+#define ESCAPE_NPAR 8
+
+/*
+ * The main tty view data structure.
+ * FIXME:
+ * 1) describe line orientation & lines list concept against screen
+ * 2) describe conversion of screen to lines
+ * 3) describe line format.
+ */
+struct tty3270 {
+	struct raw3270_view view;
+	struct tty_port port;
+	void **freemem_pages;		/* Array of pages used for freemem. */
+	struct list_head freemem;	/* List of free memory for strings. */
+
+	/* Output stuff. */
+	struct list_head lines;		/* List of lines. */
+	struct list_head update;	/* List of lines to update. */
+	unsigned char wcc;		/* Write control character. */
+	int nr_lines;			/* # lines in list. */
+	int nr_up;			/* # lines up in history. */
+	unsigned long update_flags;	/* Update indication bits. */
+	struct string *status;		/* Lower right of display. */
+	struct raw3270_request *write;	/* Single write request. */
+	struct timer_list timer;	/* Output delay timer. */
+
+	/* Current tty screen. */
+	unsigned int cx, cy;		/* Current output position. */
+	unsigned int highlight;		/* Blink/reverse/underscore */
+	unsigned int f_color;		/* Foreground color */
+	struct tty3270_line *screen;
+	unsigned int n_model, n_cols, n_rows;	/* New model & size */
+	struct work_struct resize_work;
+
+	/* Input stuff. */
+	struct string *prompt;		/* Output string for input area. */
+	struct string *input;		/* Input string for read request. */
+	struct raw3270_request *read;	/* Single read request. */
+	struct raw3270_request *kreset;	/* Single keyboard reset request. */
+	unsigned char inattr;		/* Visible/invisible input. */
+	int throttle, attn;		/* tty throttle/unthrottle. */
+	struct tasklet_struct readlet;	/* Tasklet to issue read request. */
+	struct kbd_data *kbd;		/* key_maps stuff. */
+
+	/* Escape sequence parsing. */
+	int esc_state, esc_ques, esc_npar;
+	int esc_par[ESCAPE_NPAR];
+	unsigned int saved_cx, saved_cy;
+	unsigned int saved_highlight, saved_f_color;
+
+	/* Command recalling. */
+	struct list_head rcl_lines;	/* List of recallable lines. */
+	struct list_head *rcl_walk;	/* Point in rcl_lines list. */
+	int rcl_nr, rcl_max;		/* Number/max number of rcl_lines. */
+
+	/* Character array for put_char/flush_chars. */
+	unsigned int char_count;
+	char char_buf[TTY3270_CHAR_BUF_SIZE];
+};
+
+/* tty3270->update_flags. See tty3270_update for details. */
+#define TTY_UPDATE_ERASE	1	/* Use EWRITEA instead of WRITE. */
+#define TTY_UPDATE_LIST		2	/* Update lines in tty3270->update. */
+#define TTY_UPDATE_INPUT	4	/* Update input line. */
+#define TTY_UPDATE_STATUS	8	/* Update status line. */
+#define TTY_UPDATE_ALL		16	/* Recreate screen. */
+
+static void tty3270_update(struct tty3270 *);
+static void tty3270_resize_work(struct work_struct *work);
+
+/*
+ * Setup timeout for a device. On timeout trigger an update.
+ */
+static void tty3270_set_timer(struct tty3270 *tp, int expires)
+{
+	mod_timer(&tp->timer, jiffies + expires);
+}
+
+/*
+ * The input line are the two last lines of the screen.
+ */
+static void
+tty3270_update_prompt(struct tty3270 *tp, char *input, int count)
+{
+	struct string *line;
+	unsigned int off;
+
+	line = tp->prompt;
+	if (count != 0)
+		line->string[5] = TF_INMDT;
+	else
+		line->string[5] = tp->inattr;
+	if (count > tp->view.cols * 2 - 11)
+		count = tp->view.cols * 2 - 11;
+	memcpy(line->string + 6, input, count);
+	line->string[6 + count] = TO_IC;
+	/* Clear to end of input line. */
+	if (count < tp->view.cols * 2 - 11) {
+		line->string[7 + count] = TO_RA;
+		line->string[10 + count] = 0;
+		off = tp->view.cols * tp->view.rows - 9;
+		raw3270_buffer_address(tp->view.dev, line->string+count+8, off);
+		line->len = 11 + count;
+	} else
+		line->len = 7 + count;
+	tp->update_flags |= TTY_UPDATE_INPUT;
+}
+
+static void
+tty3270_create_prompt(struct tty3270 *tp)
+{
+	static const unsigned char blueprint[] =
+		{ TO_SBA, 0, 0, 0x6e, TO_SF, TF_INPUT,
+		  /* empty input string */
+		  TO_IC, TO_RA, 0, 0, 0 };
+	struct string *line;
+	unsigned int offset;
+
+	line = alloc_string(&tp->freemem,
+			    sizeof(blueprint) + tp->view.cols * 2 - 9);
+	tp->prompt = line;
+	tp->inattr = TF_INPUT;
+	/* Copy blueprint to status line */
+	memcpy(line->string, blueprint, sizeof(blueprint));
+	line->len = sizeof(blueprint);
+	/* Set output offsets. */
+	offset = tp->view.cols * (tp->view.rows - 2);
+	raw3270_buffer_address(tp->view.dev, line->string + 1, offset);
+	offset = tp->view.cols * tp->view.rows - 9;
+	raw3270_buffer_address(tp->view.dev, line->string + 8, offset);
+
+	/* Allocate input string for reading. */
+	tp->input = alloc_string(&tp->freemem, tp->view.cols * 2 - 9 + 6);
+}
+
+/*
+ * The status line is the last line of the screen. It shows the string
+ * "Running"/"Holding" in the lower right corner of the screen.
+ */
+static void
+tty3270_update_status(struct tty3270 * tp)
+{
+	char *str;
+
+	str = (tp->nr_up != 0) ? "History" : "Running";
+	memcpy(tp->status->string + 8, str, 7);
+	codepage_convert(tp->view.ascebc, tp->status->string + 8, 7);
+	tp->update_flags |= TTY_UPDATE_STATUS;
+}
+
+static void
+tty3270_create_status(struct tty3270 * tp)
+{
+	static const unsigned char blueprint[] =
+		{ TO_SBA, 0, 0, TO_SF, TF_LOG, TO_SA, TAT_COLOR, TAC_GREEN,
+		  0, 0, 0, 0, 0, 0, 0, TO_SF, TF_LOG, TO_SA, TAT_COLOR,
+		  TAC_RESET };
+	struct string *line;
+	unsigned int offset;
+
+	line = alloc_string(&tp->freemem,sizeof(blueprint));
+	tp->status = line;
+	/* Copy blueprint to status line */
+	memcpy(line->string, blueprint, sizeof(blueprint));
+	/* Set address to start of status string (= last 9 characters). */
+	offset = tp->view.cols * tp->view.rows - 9;
+	raw3270_buffer_address(tp->view.dev, line->string + 1, offset);
+}
+
+/*
+ * Set output offsets to 3270 datastream fragment of a tty string.
+ * (TO_SBA offset at the start and TO_RA offset at the end of the string)
+ */
+static void
+tty3270_update_string(struct tty3270 *tp, struct string *line, int nr)
+{
+	unsigned char *cp;
+
+	raw3270_buffer_address(tp->view.dev, line->string + 1,
+			       tp->view.cols * nr);
+	cp = line->string + line->len - 4;
+	if (*cp == TO_RA)
+		raw3270_buffer_address(tp->view.dev, cp + 1,
+				       tp->view.cols * (nr + 1));
+}
+
+/*
+ * Rebuild update list to print all lines.
+ */
+static void
+tty3270_rebuild_update(struct tty3270 *tp)
+{
+	struct string *s, *n;
+	int line, nr_up;
+
+	/* 
+	 * Throw away update list and create a new one,
+	 * containing all lines that will fit on the screen.
+	 */
+	list_for_each_entry_safe(s, n, &tp->update, update)
+		list_del_init(&s->update);
+	line = tp->view.rows - 3;
+	nr_up = tp->nr_up;
+	list_for_each_entry_reverse(s, &tp->lines, list) {
+		if (nr_up > 0) {
+			nr_up--;
+			continue;
+		}
+		tty3270_update_string(tp, s, line);
+		list_add(&s->update, &tp->update);
+		if (--line < 0)
+			break;
+	}
+	tp->update_flags |= TTY_UPDATE_LIST;
+}
+
+/*
+ * Alloc string for size bytes. If there is not enough room in
+ * freemem, free strings until there is room.
+ */
+static struct string *
+tty3270_alloc_string(struct tty3270 *tp, size_t size)
+{
+	struct string *s, *n;
+
+	s = alloc_string(&tp->freemem, size);
+	if (s)
+		return s;
+	list_for_each_entry_safe(s, n, &tp->lines, list) {
+		BUG_ON(tp->nr_lines <= tp->view.rows - 2);
+		list_del(&s->list);
+		if (!list_empty(&s->update))
+			list_del(&s->update);
+		tp->nr_lines--;
+		if (free_string(&tp->freemem, s) >= size)
+			break;
+	}
+	s = alloc_string(&tp->freemem, size);
+	BUG_ON(!s);
+	if (tp->nr_up != 0 &&
+	    tp->nr_up + tp->view.rows - 2 >= tp->nr_lines) {
+		tp->nr_up = tp->nr_lines - tp->view.rows + 2;
+		tty3270_rebuild_update(tp);
+		tty3270_update_status(tp);
+	}
+	return s;
+}
+
+/*
+ * Add an empty line to the list.
+ */
+static void
+tty3270_blank_line(struct tty3270 *tp)
+{
+	static const unsigned char blueprint[] =
+		{ TO_SBA, 0, 0, TO_SA, TAT_EXTHI, TAX_RESET,
+		  TO_SA, TAT_COLOR, TAC_RESET, TO_RA, 0, 0, 0 };
+	struct string *s;
+
+	s = tty3270_alloc_string(tp, sizeof(blueprint));
+	memcpy(s->string, blueprint, sizeof(blueprint));
+	s->len = sizeof(blueprint);
+	list_add_tail(&s->list, &tp->lines);
+	tp->nr_lines++;
+	if (tp->nr_up != 0)
+		tp->nr_up++;
+}
+
+/*
+ * Write request completion callback.
+ */
+static void
+tty3270_write_callback(struct raw3270_request *rq, void *data)
+{
+	struct tty3270 *tp = container_of(rq->view, struct tty3270, view);
+
+	if (rq->rc != 0) {
+		/* Write wasn't successful. Refresh all. */
+		tp->update_flags = TTY_UPDATE_ALL;
+		tty3270_set_timer(tp, 1);
+	}
+	raw3270_request_reset(rq);
+	xchg(&tp->write, rq);
+}
+
+/*
+ * Update 3270 display.
+ */
+static void
+tty3270_update(struct tty3270 *tp)
+{
+	static char invalid_sba[2] = { 0xff, 0xff };
+	struct raw3270_request *wrq;
+	unsigned long updated;
+	struct string *s, *n;
+	char *sba, *str;
+	int rc, len;
+
+	wrq = xchg(&tp->write, 0);
+	if (!wrq) {
+		tty3270_set_timer(tp, 1);
+		return;
+	}
+
+	spin_lock(&tp->view.lock);
+	updated = 0;
+	if (tp->update_flags & TTY_UPDATE_ALL) {
+		tty3270_rebuild_update(tp);
+		tty3270_update_status(tp);
+		tp->update_flags = TTY_UPDATE_ERASE | TTY_UPDATE_LIST |
+			TTY_UPDATE_INPUT | TTY_UPDATE_STATUS;
+	}
+	if (tp->update_flags & TTY_UPDATE_ERASE) {
+		/* Use erase write alternate to erase display. */
+		raw3270_request_set_cmd(wrq, TC_EWRITEA);
+		updated |= TTY_UPDATE_ERASE;
+	} else
+		raw3270_request_set_cmd(wrq, TC_WRITE);
+
+	raw3270_request_add_data(wrq, &tp->wcc, 1);
+	tp->wcc = TW_NONE;
+
+	/*
+	 * Update status line.
+	 */
+	if (tp->update_flags & TTY_UPDATE_STATUS)
+		if (raw3270_request_add_data(wrq, tp->status->string,
+					     tp->status->len) == 0)
+			updated |= TTY_UPDATE_STATUS;
+
+	/*
+	 * Write input line.
+	 */
+	if (tp->update_flags & TTY_UPDATE_INPUT)
+		if (raw3270_request_add_data(wrq, tp->prompt->string,
+					     tp->prompt->len) == 0)
+			updated |= TTY_UPDATE_INPUT;
+
+	sba = invalid_sba;
+	
+	if (tp->update_flags & TTY_UPDATE_LIST) {
+		/* Write strings in the update list to the screen. */
+		list_for_each_entry_safe(s, n, &tp->update, update) {
+			str = s->string;
+			len = s->len;
+			/*
+			 * Skip TO_SBA at the start of the string if the
+			 * last output position matches the start address
+			 * of this line.
+			 */
+			if (s->string[1] == sba[0] && s->string[2] == sba[1])
+				str += 3, len -= 3;
+			if (raw3270_request_add_data(wrq, str, len) != 0)
+				break;
+			list_del_init(&s->update);
+			sba = s->string + s->len - 3;
+		}
+		if (list_empty(&tp->update))
+			updated |= TTY_UPDATE_LIST;
+	}
+	wrq->callback = tty3270_write_callback;
+	rc = raw3270_start(&tp->view, wrq);
+	if (rc == 0) {
+		tp->update_flags &= ~updated;
+		if (tp->update_flags)
+			tty3270_set_timer(tp, 1);
+	} else {
+		raw3270_request_reset(wrq);
+		xchg(&tp->write, wrq);
+	}
+	spin_unlock(&tp->view.lock);
+}
+
+/*
+ * Command recalling.
+ */
+static void
+tty3270_rcl_add(struct tty3270 *tp, char *input, int len)
+{
+	struct string *s;
+
+	tp->rcl_walk = NULL;
+	if (len <= 0)
+		return;
+	if (tp->rcl_nr >= tp->rcl_max) {
+		s = list_entry(tp->rcl_lines.next, struct string, list);
+		list_del(&s->list);
+		free_string(&tp->freemem, s);
+		tp->rcl_nr--;
+	}
+	s = tty3270_alloc_string(tp, len);
+	memcpy(s->string, input, len);
+	list_add_tail(&s->list, &tp->rcl_lines);
+	tp->rcl_nr++;
+}
+
+static void
+tty3270_rcl_backward(struct kbd_data *kbd)
+{
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
+	struct string *s;
+
+	spin_lock_bh(&tp->view.lock);
+	if (tp->inattr == TF_INPUT) {
+		if (tp->rcl_walk && tp->rcl_walk->prev != &tp->rcl_lines)
+			tp->rcl_walk = tp->rcl_walk->prev;
+		else if (!list_empty(&tp->rcl_lines))
+			tp->rcl_walk = tp->rcl_lines.prev;
+		s = tp->rcl_walk ? 
+			list_entry(tp->rcl_walk, struct string, list) : NULL;
+		if (tp->rcl_walk) {
+			s = list_entry(tp->rcl_walk, struct string, list);
+			tty3270_update_prompt(tp, s->string, s->len);
+		} else
+			tty3270_update_prompt(tp, NULL, 0);
+		tty3270_set_timer(tp, 1);
+	}
+	spin_unlock_bh(&tp->view.lock);
+}
+
+/*
+ * Deactivate tty view.
+ */
+static void
+tty3270_exit_tty(struct kbd_data *kbd)
+{
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
+
+	raw3270_deactivate_view(&tp->view);
+}
+
+/*
+ * Scroll forward in history.
+ */
+static void
+tty3270_scroll_forward(struct kbd_data *kbd)
+{
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
+	int nr_up;
+
+	spin_lock_bh(&tp->view.lock);
+	nr_up = tp->nr_up - tp->view.rows + 2;
+	if (nr_up < 0)
+		nr_up = 0;
+	if (nr_up != tp->nr_up) {
+		tp->nr_up = nr_up;
+		tty3270_rebuild_update(tp);
+		tty3270_update_status(tp);
+		tty3270_set_timer(tp, 1);
+	}
+	spin_unlock_bh(&tp->view.lock);
+}
+
+/*
+ * Scroll backward in history.
+ */
+static void
+tty3270_scroll_backward(struct kbd_data *kbd)
+{
+	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
+	int nr_up;
+
+	spin_lock_bh(&tp->view.lock);
+	nr_up = tp->nr_up + tp->view.rows - 2;
+	if (nr_up + tp->view.rows - 2 > tp->nr_lines)
+		nr_up = tp->nr_lines - tp->view.rows + 2;
+	if (nr_up != tp->nr_up) {
+		tp->nr_up = nr_up;
+		tty3270_rebuild_update(tp);
+		tty3270_update_status(tp);
+		tty3270_set_timer(tp, 1);
+	}
+	spin_unlock_bh(&tp->view.lock);
+}
+
+/*
+ * Pass input line to tty.
+ */
+static void
+tty3270_read_tasklet(struct raw3270_request *rrq)
+{
+	static char kreset_data = TW_KR;
+	struct tty3270 *tp = container_of(rrq->view, struct tty3270, view);
+	char *input;
+	int len;
+
+	spin_lock_bh(&tp->view.lock);
+	/*
+	 * Two AID keys are special: For 0x7d (enter) the input line
+	 * has to be emitted to the tty and for 0x6d the screen
+	 * needs to be redrawn.
+	 */
+	input = NULL;
+	len = 0;
+	if (tp->input->string[0] == 0x7d) {
+		/* Enter: write input to tty. */
+		input = tp->input->string + 6;
+		len = tp->input->len - 6 - rrq->rescnt;
+		if (tp->inattr != TF_INPUTN)
+			tty3270_rcl_add(tp, input, len);
+		if (tp->nr_up > 0) {
+			tp->nr_up = 0;
+			tty3270_rebuild_update(tp);
+			tty3270_update_status(tp);
+		}
+		/* Clear input area. */
+		tty3270_update_prompt(tp, NULL, 0);
+		tty3270_set_timer(tp, 1);
+	} else if (tp->input->string[0] == 0x6d) {
+		/* Display has been cleared. Redraw. */
+		tp->update_flags = TTY_UPDATE_ALL;
+		tty3270_set_timer(tp, 1);
+	}
+	spin_unlock_bh(&tp->view.lock);
+
+	/* Start keyboard reset command. */
+	raw3270_request_reset(tp->kreset);
+	raw3270_request_set_cmd(tp->kreset, TC_WRITE);
+	raw3270_request_add_data(tp->kreset, &kreset_data, 1);
+	raw3270_start(&tp->view, tp->kreset);
+
+	while (len-- > 0)
+		kbd_keycode(tp->kbd, *input++);
+	/* Emit keycode for AID byte. */
+	kbd_keycode(tp->kbd, 256 + tp->input->string[0]);
+
+	raw3270_request_reset(rrq);
+	xchg(&tp->read, rrq);
+	raw3270_put_view(&tp->view);
+}
+
+/*
+ * Read request completion callback.
+ */
+static void
+tty3270_read_callback(struct raw3270_request *rq, void *data)
+{
+	struct tty3270 *tp = container_of(rq->view, struct tty3270, view);
+	raw3270_get_view(rq->view);
+	/* Schedule tasklet to pass input to tty. */
+	tasklet_schedule(&tp->readlet);
+}
+
+/*
+ * Issue a read request. Call with device lock.
+ */
+static void
+tty3270_issue_read(struct tty3270 *tp, int lock)
+{
+	struct raw3270_request *rrq;
+	int rc;
+
+	rrq = xchg(&tp->read, 0);
+	if (!rrq)
+		/* Read already scheduled. */
+		return;
+	rrq->callback = tty3270_read_callback;
+	rrq->callback_data = tp;
+	raw3270_request_set_cmd(rrq, TC_READMOD);
+	raw3270_request_set_data(rrq, tp->input->string, tp->input->len);
+	/* Issue the read modified request. */
+	if (lock) {
+		rc = raw3270_start(&tp->view, rrq);
+	} else
+		rc = raw3270_start_irq(&tp->view, rrq);
+	if (rc) {
+		raw3270_request_reset(rrq);
+		xchg(&tp->read, rrq);
+	}
+}
+
+/*
+ * Switch to the tty view.
+ */
+static int
+tty3270_activate(struct raw3270_view *view)
+{
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+
+	tp->update_flags = TTY_UPDATE_ALL;
+	tty3270_set_timer(tp, 1);
+	return 0;
+}
+
+static void
+tty3270_deactivate(struct raw3270_view *view)
+{
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+
+	del_timer(&tp->timer);
+}
+
+static int
+tty3270_irq(struct tty3270 *tp, struct raw3270_request *rq, struct irb *irb)
+{
+	/* Handle ATTN. Schedule tasklet to read aid. */
+	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
+		if (!tp->throttle)
+			tty3270_issue_read(tp, 0);
+		else
+			tp->attn = 1;
+	}
+
+	if (rq) {
+		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
+			rq->rc = -EIO;
+		else
+			/* Normal end. Copy residual count. */
+			rq->rescnt = irb->scsw.cmd.count;
+	}
+	return RAW3270_IO_DONE;
+}
+
+/*
+ * Allocate tty3270 structure.
+ */
+static struct tty3270 *
+tty3270_alloc_view(void)
+{
+	struct tty3270 *tp;
+	int pages;
+
+	tp = kzalloc(sizeof(struct tty3270), GFP_KERNEL);
+	if (!tp)
+		goto out_err;
+	tp->freemem_pages =
+		kmalloc(sizeof(void *) * TTY3270_STRING_PAGES, GFP_KERNEL);
+	if (!tp->freemem_pages)
+		goto out_tp;
+	INIT_LIST_HEAD(&tp->freemem);
+	INIT_LIST_HEAD(&tp->lines);
+	INIT_LIST_HEAD(&tp->update);
+	INIT_LIST_HEAD(&tp->rcl_lines);
+	tp->rcl_max = 20;
+
+	for (pages = 0; pages < TTY3270_STRING_PAGES; pages++) {
+		tp->freemem_pages[pages] = (void *)
+			__get_free_pages(GFP_KERNEL|GFP_DMA, 0);
+		if (!tp->freemem_pages[pages])
+			goto out_pages;
+		add_string_memory(&tp->freemem,
+				  tp->freemem_pages[pages], PAGE_SIZE);
+	}
+	tp->write = raw3270_request_alloc(TTY3270_OUTPUT_BUFFER_SIZE);
+	if (IS_ERR(tp->write))
+		goto out_pages;
+	tp->read = raw3270_request_alloc(0);
+	if (IS_ERR(tp->read))
+		goto out_write;
+	tp->kreset = raw3270_request_alloc(1);
+	if (IS_ERR(tp->kreset))
+		goto out_read;
+	tp->kbd = kbd_alloc();
+	if (!tp->kbd)
+		goto out_reset;
+
+	tty_port_init(&tp->port);
+	setup_timer(&tp->timer, (void (*)(unsigned long)) tty3270_update,
+		    (unsigned long) tp);
+	tasklet_init(&tp->readlet,
+		     (void (*)(unsigned long)) tty3270_read_tasklet,
+		     (unsigned long) tp->read);
+	INIT_WORK(&tp->resize_work, tty3270_resize_work);
+
+	return tp;
+
+out_reset:
+	raw3270_request_free(tp->kreset);
+out_read:
+	raw3270_request_free(tp->read);
+out_write:
+	raw3270_request_free(tp->write);
+out_pages:
+	while (pages--)
+		free_pages((unsigned long) tp->freemem_pages[pages], 0);
+	kfree(tp->freemem_pages);
+	tty_port_destroy(&tp->port);
+out_tp:
+	kfree(tp);
+out_err:
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Free tty3270 structure.
+ */
+static void
+tty3270_free_view(struct tty3270 *tp)
+{
+	int pages;
+
+	kbd_free(tp->kbd);
+	raw3270_request_free(tp->kreset);
+	raw3270_request_free(tp->read);
+	raw3270_request_free(tp->write);
+	for (pages = 0; pages < TTY3270_STRING_PAGES; pages++)
+		free_pages((unsigned long) tp->freemem_pages[pages], 0);
+	kfree(tp->freemem_pages);
+	tty_port_destroy(&tp->port);
+	kfree(tp);
+}
+
+/*
+ * Allocate tty3270 screen.
+ */
+static struct tty3270_line *
+tty3270_alloc_screen(unsigned int rows, unsigned int cols)
+{
+	struct tty3270_line *screen;
+	unsigned long size;
+	int lines;
+
+	size = sizeof(struct tty3270_line) * (rows - 2);
+	screen = kzalloc(size, GFP_KERNEL);
+	if (!screen)
+		goto out_err;
+	for (lines = 0; lines < rows - 2; lines++) {
+		size = sizeof(struct tty3270_cell) * cols;
+		screen[lines].cells = kzalloc(size, GFP_KERNEL);
+		if (!screen[lines].cells)
+			goto out_screen;
+	}
+	return screen;
+out_screen:
+	while (lines--)
+		kfree(screen[lines].cells);
+	kfree(screen);
+out_err:
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Free tty3270 screen.
+ */
+static void
+tty3270_free_screen(struct tty3270_line *screen, unsigned int rows)
+{
+	int lines;
+
+	for (lines = 0; lines < rows - 2; lines++)
+		kfree(screen[lines].cells);
+	kfree(screen);
+}
+
+/*
+ * Resize tty3270 screen
+ */
+static void tty3270_resize_work(struct work_struct *work)
+{
+	struct tty3270 *tp = container_of(work, struct tty3270, resize_work);
+	struct tty3270_line *screen, *oscreen;
+	struct tty_struct *tty;
+	unsigned int orows;
+	struct winsize ws;
+
+	screen = tty3270_alloc_screen(tp->n_rows, tp->n_cols);
+	if (IS_ERR(screen))
+		return;
+	/* Switch to new output size */
+	spin_lock_bh(&tp->view.lock);
+	oscreen = tp->screen;
+	orows = tp->view.rows;
+	tp->view.model = tp->n_model;
+	tp->view.rows = tp->n_rows;
+	tp->view.cols = tp->n_cols;
+	tp->screen = screen;
+	free_string(&tp->freemem, tp->prompt);
+	free_string(&tp->freemem, tp->status);
+	tty3270_create_prompt(tp);
+	tty3270_create_status(tp);
+	tp->nr_up = 0;
+	while (tp->nr_lines < tp->view.rows - 2)
+		tty3270_blank_line(tp);
+	tp->update_flags = TTY_UPDATE_ALL;
+	spin_unlock_bh(&tp->view.lock);
+	tty3270_free_screen(oscreen, orows);
+	tty3270_set_timer(tp, 1);
+	/* Informat tty layer about new size */
+	tty = tty_port_tty_get(&tp->port);
+	if (!tty)
+		return;
+	ws.ws_row = tp->view.rows - 2;
+	ws.ws_col = tp->view.cols;
+	tty_do_resize(tty, &ws);
+}
+
+static void
+tty3270_resize(struct raw3270_view *view, int model, int rows, int cols)
+{
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+
+	tp->n_model = model;
+	tp->n_rows = rows;
+	tp->n_cols = cols;
+	schedule_work(&tp->resize_work);
+}
+
+/*
+ * Unlink tty3270 data structure from tty.
+ */
+static void
+tty3270_release(struct raw3270_view *view)
+{
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+	struct tty_struct *tty = tty_port_tty_get(&tp->port);
+
+	if (tty) {
+		tty->driver_data = NULL;
+		tty_port_tty_set(&tp->port, NULL);
+		tty_hangup(tty);
+		raw3270_put_view(&tp->view);
+		tty_kref_put(tty);
+	}
+}
+
+/*
+ * Free tty3270 data structure
+ */
+static void
+tty3270_free(struct raw3270_view *view)
+{
+	struct tty3270 *tp = container_of(view, struct tty3270, view);
+
+	del_timer_sync(&tp->timer);
+	tty3270_free_screen(tp->screen, tp->view.rows);
+	tty3270_free_view(tp);
+}
+
+/*
+ * Delayed freeing of tty3270 views.
+ */
+static void
+tty3270_del_views(void)
+{
+	int i;
+
+	for (i = RAW3270_FIRSTMINOR; i <= tty3270_max_index; i++) {
+		struct raw3270_view *view = raw3270_find_view(&tty3270_fn, i);
+		if (!IS_ERR(view))
+			raw3270_del_view(view);
+	}
+}
+
+static struct raw3270_fn tty3270_fn = {
+	.activate = tty3270_activate,
+	.deactivate = tty3270_deactivate,
+	.intv = (void *) tty3270_irq,
+	.release = tty3270_release,
+	.free = tty3270_free,
+	.resize = tty3270_resize
+};
+
+/*
+ * This routine is called whenever a 3270 tty is opened first time.
+ */
+static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct raw3270_view *view;
+	struct tty3270 *tp;
+	int i, rc;
+
+	/* Check if the tty3270 is already there. */
+	view = raw3270_find_view(&tty3270_fn, tty->index + RAW3270_FIRSTMINOR);
+	if (!IS_ERR(view)) {
+		tp = container_of(view, struct tty3270, view);
+		tty->driver_data = tp;
+		tty->winsize.ws_row = tp->view.rows - 2;
+		tty->winsize.ws_col = tp->view.cols;
+		tp->port.low_latency = 0;
+		/* why to reassign? */
+		tty_port_tty_set(&tp->port, tty);
+		tp->inattr = TF_INPUT;
+		return tty_port_install(&tp->port, driver, tty);
+	}
+	if (tty3270_max_index < tty->index + 1)
+		tty3270_max_index = tty->index + 1;
+
+	/* Allocate tty3270 structure on first open. */
+	tp = tty3270_alloc_view();
+	if (IS_ERR(tp))
+		return PTR_ERR(tp);
+
+	rc = raw3270_add_view(&tp->view, &tty3270_fn,
+			      tty->index + RAW3270_FIRSTMINOR);
+	if (rc) {
+		tty3270_free_view(tp);
+		return rc;
+	}
+
+	tp->screen = tty3270_alloc_screen(tp->view.rows, tp->view.cols);
+	if (IS_ERR(tp->screen)) {
+		rc = PTR_ERR(tp->screen);
+		raw3270_put_view(&tp->view);
+		raw3270_del_view(&tp->view);
+		tty3270_free_view(tp);
+		return rc;
+	}
+
+	tty_port_tty_set(&tp->port, tty);
+	tp->port.low_latency = 0;
+	tty->winsize.ws_row = tp->view.rows - 2;
+	tty->winsize.ws_col = tp->view.cols;
+
+	tty3270_create_prompt(tp);
+	tty3270_create_status(tp);
+	tty3270_update_status(tp);
+
+	/* Create blank line for every line in the tty output area. */
+	for (i = 0; i < tp->view.rows - 2; i++)
+		tty3270_blank_line(tp);
+
+	tp->kbd->port = &tp->port;
+	tp->kbd->fn_handler[KVAL(K_INCRCONSOLE)] = tty3270_exit_tty;
+	tp->kbd->fn_handler[KVAL(K_SCROLLBACK)] = tty3270_scroll_backward;
+	tp->kbd->fn_handler[KVAL(K_SCROLLFORW)] = tty3270_scroll_forward;
+	tp->kbd->fn_handler[KVAL(K_CONS)] = tty3270_rcl_backward;
+	kbd_ascebc(tp->kbd, tp->view.ascebc);
+
+	raw3270_activate_view(&tp->view);
+
+	rc = tty_port_install(&tp->port, driver, tty);
+	if (rc) {
+		raw3270_put_view(&tp->view);
+		return rc;
+	}
+
+	tty->driver_data = tp;
+
+	return 0;
+}
+
+/*
+ * This routine is called whenever a 3270 tty is opened.
+ */
+static int
+tty3270_open(struct tty_struct *tty, struct file *filp)
+{
+	struct tty3270 *tp = tty->driver_data;
+	struct tty_port *port = &tp->port;
+
+	port->count++;
+	tty_port_tty_set(port, tty);
+	return 0;
+}
+
+/*
+ * This routine is called when the 3270 tty is closed. We wait
+ * for the remaining request to be completed. Then we clean up.
+ */
+static void
+tty3270_close(struct tty_struct *tty, struct file * filp)
+{
+	struct tty3270 *tp = tty->driver_data;
+
+	if (tty->count > 1)
+		return;
+	if (tp) {
+		tty->driver_data = NULL;
+		tty_port_tty_set(&tp->port, NULL);
+	}
+}
+
+static void tty3270_cleanup(struct tty_struct *tty)
+{
+	struct tty3270 *tp = tty->driver_data;
+
+	if (tp)
+		raw3270_put_view(&tp->view);
+}
+
+/*
+ * We always have room.
+ */
+static int
+tty3270_write_room(struct tty_struct *tty)
+{
+	return INT_MAX;
+}
+
+/*
+ * Insert character into the screen at the current position with the
+ * current color and highlight. This function does NOT do cursor movement.
+ */
+static void tty3270_put_character(struct tty3270 *tp, char ch)
+{
+	struct tty3270_line *line;
+	struct tty3270_cell *cell;
+
+	line = tp->screen + tp->cy;
+	if (line->len <= tp->cx) {
+		while (line->len < tp->cx) {
+			cell = line->cells + line->len;
+			cell->character = tp->view.ascebc[' '];
+			cell->highlight = tp->highlight;
+			cell->f_color = tp->f_color;
+			line->len++;
+		}
+		line->len++;
+	}
+	cell = line->cells + tp->cx;
+	cell->character = tp->view.ascebc[(unsigned int) ch];
+	cell->highlight = tp->highlight;
+	cell->f_color = tp->f_color;
+}
+
+/*
+ * Convert a tty3270_line to a 3270 data fragment usable for output.
+ */
+static void
+tty3270_convert_line(struct tty3270 *tp, int line_nr)
+{
+	struct tty3270_line *line;
+	struct tty3270_cell *cell;
+	struct string *s, *n;
+	unsigned char highlight;
+	unsigned char f_color;
+	char *cp;
+	int flen, i;
+
+	/* Determine how long the fragment will be. */
+	flen = 3;		/* Prefix (TO_SBA). */
+	line = tp->screen + line_nr;
+	flen += line->len;
+	highlight = TAX_RESET;
+	f_color = TAC_RESET;
+	for (i = 0, cell = line->cells; i < line->len; i++, cell++) {
+		if (cell->highlight != highlight) {
+			flen += 3;	/* TO_SA to switch highlight. */
+			highlight = cell->highlight;
+		}
+		if (cell->f_color != f_color) {
+			flen += 3;	/* TO_SA to switch color. */
+			f_color = cell->f_color;
+		}
+	}
+	if (highlight != TAX_RESET)
+		flen += 3;	/* TO_SA to reset hightlight. */
+	if (f_color != TAC_RESET)
+		flen += 3;	/* TO_SA to reset color. */
+	if (line->len < tp->view.cols)
+		flen += 4;	/* Postfix (TO_RA). */
+
+	/* Find the line in the list. */
+	i = tp->view.rows - 2 - line_nr;
+	list_for_each_entry_reverse(s, &tp->lines, list)
+		if (--i <= 0)
+			break;
+	/*
+	 * Check if the line needs to get reallocated.
+	 */
+	if (s->len != flen) {
+		/* Reallocate string. */
+		n = tty3270_alloc_string(tp, flen);
+		list_add(&n->list, &s->list);
+		list_del_init(&s->list);
+		if (!list_empty(&s->update))
+			list_del_init(&s->update);
+		free_string(&tp->freemem, s);
+		s = n;
+	}
+
+	/* Write 3270 data fragment. */
+	cp = s->string;
+	*cp++ = TO_SBA;
+	*cp++ = 0;
+	*cp++ = 0;
+
+	highlight = TAX_RESET;
+	f_color = TAC_RESET;
+	for (i = 0, cell = line->cells; i < line->len; i++, cell++) {
+		if (cell->highlight != highlight) {
+			*cp++ = TO_SA;
+			*cp++ = TAT_EXTHI;
+			*cp++ = cell->highlight;
+			highlight = cell->highlight;
+		}
+		if (cell->f_color != f_color) {
+			*cp++ = TO_SA;
+			*cp++ = TAT_COLOR;
+			*cp++ = cell->f_color;
+			f_color = cell->f_color;
+		}
+		*cp++ = cell->character;
+	}
+	if (highlight != TAX_RESET) {
+		*cp++ = TO_SA;
+		*cp++ = TAT_EXTHI;
+		*cp++ = TAX_RESET;
+	}
+	if (f_color != TAC_RESET) {
+		*cp++ = TO_SA;
+		*cp++ = TAT_COLOR;
+		*cp++ = TAC_RESET;
+	}
+	if (line->len < tp->view.cols) {
+		*cp++ = TO_RA;
+		*cp++ = 0;
+		*cp++ = 0;
+		*cp++ = 0;
+	}
+
+	if (tp->nr_up + line_nr < tp->view.rows - 2) {
+		/* Line is currently visible on screen. */
+		tty3270_update_string(tp, s, line_nr);
+		/* Add line to update list. */
+		if (list_empty(&s->update)) {
+			list_add_tail(&s->update, &tp->update);
+			tp->update_flags |= TTY_UPDATE_LIST;
+		}
+	}
+}
+
+/*
+ * Do carriage return.
+ */
+static void
+tty3270_cr(struct tty3270 *tp)
+{
+	tp->cx = 0;
+}
+
+/*
+ * Do line feed.
+ */
+static void
+tty3270_lf(struct tty3270 *tp)
+{
+	struct tty3270_line temp;
+	int i;
+
+	tty3270_convert_line(tp, tp->cy);
+	if (tp->cy < tp->view.rows - 3) {
+		tp->cy++;
+		return;
+	}
+	/* Last line just filled up. Add new, blank line. */
+	tty3270_blank_line(tp);
+	temp = tp->screen[0];
+	temp.len = 0;
+	for (i = 0; i < tp->view.rows - 3; i++)
+		tp->screen[i] = tp->screen[i+1];
+	tp->screen[tp->view.rows - 3] = temp;
+	tty3270_rebuild_update(tp);
+}
+
+static void
+tty3270_ri(struct tty3270 *tp)
+{
+	if (tp->cy > 0) {
+	    tty3270_convert_line(tp, tp->cy);
+	    tp->cy--;
+	}
+}
+
+/*
+ * Insert characters at current position.
+ */
+static void
+tty3270_insert_characters(struct tty3270 *tp, int n)
+{
+	struct tty3270_line *line;
+	int k;
+
+	line = tp->screen + tp->cy;
+	while (line->len < tp->cx) {
+		line->cells[line->len].character = tp->view.ascebc[' '];
+		line->cells[line->len].highlight = TAX_RESET;
+		line->cells[line->len].f_color = TAC_RESET;
+		line->len++;
+	}
+	if (n > tp->view.cols - tp->cx)
+		n = tp->view.cols - tp->cx;
+	k = min_t(int, line->len - tp->cx, tp->view.cols - tp->cx - n);
+	while (k--)
+		line->cells[tp->cx + n + k] = line->cells[tp->cx + k];
+	line->len += n;
+	if (line->len > tp->view.cols)
+		line->len = tp->view.cols;
+	while (n-- > 0) {
+		line->cells[tp->cx + n].character = tp->view.ascebc[' '];
+		line->cells[tp->cx + n].highlight = tp->highlight;
+		line->cells[tp->cx + n].f_color = tp->f_color;
+	}
+}
+
+/*
+ * Delete characters at current position.
+ */
+static void
+tty3270_delete_characters(struct tty3270 *tp, int n)
+{
+	struct tty3270_line *line;
+	int i;
+
+	line = tp->screen + tp->cy;
+	if (line->len <= tp->cx)
+		return;
+	if (line->len - tp->cx <= n) {
+		line->len = tp->cx;
+		return;
+	}
+	for (i = tp->cx; i + n < line->len; i++)
+		line->cells[i] = line->cells[i + n];
+	line->len -= n;
+}
+
+/*
+ * Erase characters at current position.
+ */
+static void
+tty3270_erase_characters(struct tty3270 *tp, int n)
+{
+	struct tty3270_line *line;
+	struct tty3270_cell *cell;
+
+	line = tp->screen + tp->cy;
+	while (line->len > tp->cx && n-- > 0) {
+		cell = line->cells + tp->cx++;
+		cell->character = ' ';
+		cell->highlight = TAX_RESET;
+		cell->f_color = TAC_RESET;
+	}
+	tp->cx += n;
+	tp->cx = min_t(int, tp->cx, tp->view.cols - 1);
+}
+
+/*
+ * Erase line, 3 different cases:
+ *  Esc [ 0 K	Erase from current position to end of line inclusive
+ *  Esc [ 1 K	Erase from beginning of line to current position inclusive
+ *  Esc [ 2 K	Erase entire line (without moving cursor)
+ */
+static void
+tty3270_erase_line(struct tty3270 *tp, int mode)
+{
+	struct tty3270_line *line;
+	struct tty3270_cell *cell;
+	int i;
+
+	line = tp->screen + tp->cy;
+	if (mode == 0)
+		line->len = tp->cx;
+	else if (mode == 1) {
+		for (i = 0; i < tp->cx; i++) {
+			cell = line->cells + i;
+			cell->character = ' ';
+			cell->highlight = TAX_RESET;
+			cell->f_color = TAC_RESET;
+		}
+		if (line->len <= tp->cx)
+			line->len = tp->cx + 1;
+	} else if (mode == 2)
+		line->len = 0;
+	tty3270_convert_line(tp, tp->cy);
+}
+
+/*
+ * Erase display, 3 different cases:
+ *  Esc [ 0 J	Erase from current position to bottom of screen inclusive
+ *  Esc [ 1 J	Erase from top of screen to current position inclusive
+ *  Esc [ 2 J	Erase entire screen (without moving the cursor)
+ */
+static void
+tty3270_erase_display(struct tty3270 *tp, int mode)
+{
+	int i;
+
+	if (mode == 0) {
+		tty3270_erase_line(tp, 0);
+		for (i = tp->cy + 1; i < tp->view.rows - 2; i++) {
+			tp->screen[i].len = 0;
+			tty3270_convert_line(tp, i);
+		}
+	} else if (mode == 1) {
+		for (i = 0; i < tp->cy; i++) {
+			tp->screen[i].len = 0;
+			tty3270_convert_line(tp, i);
+		}
+		tty3270_erase_line(tp, 1);
+	} else if (mode == 2) {
+		for (i = 0; i < tp->view.rows - 2; i++) {
+			tp->screen[i].len = 0;
+			tty3270_convert_line(tp, i);
+		}
+	}
+	tty3270_rebuild_update(tp);
+}
+
+/*
+ * Set attributes found in an escape sequence.
+ *  Esc [ <attr> ; <attr> ; ... m
+ */
+static void
+tty3270_set_attributes(struct tty3270 *tp)
+{
+	static unsigned char f_colors[] = {
+		TAC_DEFAULT, TAC_RED, TAC_GREEN, TAC_YELLOW, TAC_BLUE,
+		TAC_PINK, TAC_TURQ, TAC_WHITE, 0, TAC_DEFAULT
+	};
+	int i, attr;
+
+	for (i = 0; i <= tp->esc_npar; i++) {
+		attr = tp->esc_par[i];
+		switch (attr) {
+		case 0:		/* Reset */
+			tp->highlight = TAX_RESET;
+			tp->f_color = TAC_RESET;
+			break;
+		/* Highlight. */
+		case 4:		/* Start underlining. */
+			tp->highlight = TAX_UNDER;
+			break;
+		case 5:		/* Start blink. */
+			tp->highlight = TAX_BLINK;
+			break;
+		case 7:		/* Start reverse. */
+			tp->highlight = TAX_REVER;
+			break;
+		case 24:	/* End underlining */
+			if (tp->highlight == TAX_UNDER)
+				tp->highlight = TAX_RESET;
+			break;
+		case 25:	/* End blink. */
+			if (tp->highlight == TAX_BLINK)
+				tp->highlight = TAX_RESET;
+			break;
+		case 27:	/* End reverse. */
+			if (tp->highlight == TAX_REVER)
+				tp->highlight = TAX_RESET;
+			break;
+		/* Foreground color. */
+		case 30:	/* Black */
+		case 31:	/* Red */
+		case 32:	/* Green */
+		case 33:	/* Yellow */
+		case 34:	/* Blue */
+		case 35:	/* Magenta */
+		case 36:	/* Cyan */
+		case 37:	/* White */
+		case 39:	/* Black */
+			tp->f_color = f_colors[attr - 30];
+			break;
+		}
+	}
+}
+
+static inline int
+tty3270_getpar(struct tty3270 *tp, int ix)
+{
+	return (tp->esc_par[ix] > 0) ? tp->esc_par[ix] : 1;
+}
+
+static void
+tty3270_goto_xy(struct tty3270 *tp, int cx, int cy)
+{
+	int max_cx = max(0, cx);
+	int max_cy = max(0, cy);
+
+	tp->cx = min_t(int, tp->view.cols - 1, max_cx);
+	cy = min_t(int, tp->view.rows - 3, max_cy);
+	if (cy != tp->cy) {
+		tty3270_convert_line(tp, tp->cy);
+		tp->cy = cy;
+	}
+}
+
+/*
+ * Process escape sequences. Known sequences:
+ *  Esc 7			Save Cursor Position
+ *  Esc 8			Restore Cursor Position
+ *  Esc [ Pn ; Pn ; .. m	Set attributes
+ *  Esc [ Pn ; Pn H		Cursor Position
+ *  Esc [ Pn ; Pn f		Cursor Position
+ *  Esc [ Pn A			Cursor Up
+ *  Esc [ Pn B			Cursor Down
+ *  Esc [ Pn C			Cursor Forward
+ *  Esc [ Pn D			Cursor Backward
+ *  Esc [ Pn G			Cursor Horizontal Absolute
+ *  Esc [ Pn X			Erase Characters
+ *  Esc [ Ps J			Erase in Display
+ *  Esc [ Ps K			Erase in Line
+ * // FIXME: add all the new ones.
+ *
+ *  Pn is a numeric parameter, a string of zero or more decimal digits.
+ *  Ps is a selective parameter.
+ */
+static void
+tty3270_escape_sequence(struct tty3270 *tp, char ch)
+{
+	enum { ESnormal, ESesc, ESsquare, ESgetpars };
+
+	if (tp->esc_state == ESnormal) {
+		if (ch == 0x1b)
+			/* Starting new escape sequence. */
+			tp->esc_state = ESesc;
+		return;
+	}
+	if (tp->esc_state == ESesc) {
+		tp->esc_state = ESnormal;
+		switch (ch) {
+		case '[':
+			tp->esc_state = ESsquare;
+			break;
+		case 'E':
+			tty3270_cr(tp);
+			tty3270_lf(tp);
+			break;
+		case 'M':
+			tty3270_ri(tp);
+			break;
+		case 'D':
+			tty3270_lf(tp);
+			break;
+		case 'Z':		/* Respond ID. */
+			kbd_puts_queue(&tp->port, "\033[?6c");
+			break;
+		case '7':		/* Save cursor position. */
+			tp->saved_cx = tp->cx;
+			tp->saved_cy = tp->cy;
+			tp->saved_highlight = tp->highlight;
+			tp->saved_f_color = tp->f_color;
+			break;
+		case '8':		/* Restore cursor position. */
+			tty3270_convert_line(tp, tp->cy);
+			tty3270_goto_xy(tp, tp->saved_cx, tp->saved_cy);
+			tp->highlight = tp->saved_highlight;
+			tp->f_color = tp->saved_f_color;
+			break;
+		case 'c':		/* Reset terminal. */
+			tp->cx = tp->saved_cx = 0;
+			tp->cy = tp->saved_cy = 0;
+			tp->highlight = tp->saved_highlight = TAX_RESET;
+			tp->f_color = tp->saved_f_color = TAC_RESET;
+			tty3270_erase_display(tp, 2);
+			break;
+		}
+		return;
+	}
+	if (tp->esc_state == ESsquare) {
+		tp->esc_state = ESgetpars;
+		memset(tp->esc_par, 0, sizeof(tp->esc_par));
+		tp->esc_npar = 0;
+		tp->esc_ques = (ch == '?');
+		if (tp->esc_ques)
+			return;
+	}
+	if (tp->esc_state == ESgetpars) {
+		if (ch == ';' && tp->esc_npar < ESCAPE_NPAR - 1) {
+			tp->esc_npar++;
+			return;
+		}
+		if (ch >= '0' && ch <= '9') {
+			tp->esc_par[tp->esc_npar] *= 10;
+			tp->esc_par[tp->esc_npar] += ch - '0';
+			return;
+		}
+	}
+	tp->esc_state = ESnormal;
+	if (ch == 'n' && !tp->esc_ques) {
+		if (tp->esc_par[0] == 5)		/* Status report. */
+			kbd_puts_queue(&tp->port, "\033[0n");
+		else if (tp->esc_par[0] == 6) {	/* Cursor report. */
+			char buf[40];
+			sprintf(buf, "\033[%d;%dR", tp->cy + 1, tp->cx + 1);
+			kbd_puts_queue(&tp->port, buf);
+		}
+		return;
+	}
+	if (tp->esc_ques)
+		return;
+	switch (ch) {
+	case 'm':
+		tty3270_set_attributes(tp);
+		break;
+	case 'H':	/* Set cursor position. */
+	case 'f':
+		tty3270_goto_xy(tp, tty3270_getpar(tp, 1) - 1,
+				tty3270_getpar(tp, 0) - 1);
+		break;
+	case 'd':	/* Set y position. */
+		tty3270_goto_xy(tp, tp->cx, tty3270_getpar(tp, 0) - 1);
+		break;
+	case 'A':	/* Cursor up. */
+	case 'F':
+		tty3270_goto_xy(tp, tp->cx, tp->cy - tty3270_getpar(tp, 0));
+		break;
+	case 'B':	/* Cursor down. */
+	case 'e':
+	case 'E':
+		tty3270_goto_xy(tp, tp->cx, tp->cy + tty3270_getpar(tp, 0));
+		break;
+	case 'C':	/* Cursor forward. */
+	case 'a':
+		tty3270_goto_xy(tp, tp->cx + tty3270_getpar(tp, 0), tp->cy);
+		break;
+	case 'D':	/* Cursor backward. */
+		tty3270_goto_xy(tp, tp->cx - tty3270_getpar(tp, 0), tp->cy);
+		break;
+	case 'G':	/* Set x position. */
+	case '`':
+		tty3270_goto_xy(tp, tty3270_getpar(tp, 0), tp->cy);
+		break;
+	case 'X':	/* Erase Characters. */
+		tty3270_erase_characters(tp, tty3270_getpar(tp, 0));
+		break;
+	case 'J':	/* Erase display. */
+		tty3270_erase_display(tp, tp->esc_par[0]);
+		break;
+	case 'K':	/* Erase line. */
+		tty3270_erase_line(tp, tp->esc_par[0]);
+		break;
+	case 'P':	/* Delete characters. */
+		tty3270_delete_characters(tp, tty3270_getpar(tp, 0));
+		break;
+	case '@':	/* Insert characters. */
+		tty3270_insert_characters(tp, tty3270_getpar(tp, 0));
+		break;
+	case 's':	/* Save cursor position. */
+		tp->saved_cx = tp->cx;
+		tp->saved_cy = tp->cy;
+		tp->saved_highlight = tp->highlight;
+		tp->saved_f_color = tp->f_color;
+		break;
+	case 'u':	/* Restore cursor position. */
+		tty3270_convert_line(tp, tp->cy);
+		tty3270_goto_xy(tp, tp->saved_cx, tp->saved_cy);
+		tp->highlight = tp->saved_highlight;
+		tp->f_color = tp->saved_f_color;
+		break;
+	}
+}
+
+/*
+ * String write routine for 3270 ttys
+ */
+static void
+tty3270_do_write(struct tty3270 *tp, struct tty_struct *tty,
+		const unsigned char *buf, int count)
+{
+	int i_msg, i;
+
+	spin_lock_bh(&tp->view.lock);
+	for (i_msg = 0; !tty->stopped && i_msg < count; i_msg++) {
+		if (tp->esc_state != 0) {
+			/* Continue escape sequence. */
+			tty3270_escape_sequence(tp, buf[i_msg]);
+			continue;
+		}
+
+		switch (buf[i_msg]) {
+		case 0x07:		/* '\a' -- Alarm */
+			tp->wcc |= TW_PLUSALARM;
+			break;
+		case 0x08:		/* Backspace. */
+			if (tp->cx > 0) {
+				tp->cx--;
+				tty3270_put_character(tp, ' ');
+			}
+			break;
+		case 0x09:		/* '\t' -- Tabulate */
+			for (i = tp->cx % 8; i < 8; i++) {
+				if (tp->cx >= tp->view.cols) {
+					tty3270_cr(tp);
+					tty3270_lf(tp);
+					break;
+				}
+				tty3270_put_character(tp, ' ');
+				tp->cx++;
+			}
+			break;
+		case 0x0a:		/* '\n' -- New Line */
+			tty3270_cr(tp);
+			tty3270_lf(tp);
+			break;
+		case 0x0c:		/* '\f' -- Form Feed */
+			tty3270_erase_display(tp, 2);
+			tp->cx = tp->cy = 0;
+			break;
+		case 0x0d:		/* '\r' -- Carriage Return */
+			tp->cx = 0;
+			break;
+		case 0x0f:		/* SuSE "exit alternate mode" */
+			break;
+		case 0x1b:		/* Start escape sequence. */
+			tty3270_escape_sequence(tp, buf[i_msg]);
+			break;
+		default:		/* Insert normal character. */
+			if (tp->cx >= tp->view.cols) {
+				tty3270_cr(tp);
+				tty3270_lf(tp);
+			}
+			tty3270_put_character(tp, buf[i_msg]);
+			tp->cx++;
+			break;
+		}
+	}
+	/* Convert current line to 3270 data fragment. */
+	tty3270_convert_line(tp, tp->cy);
+
+	/* Setup timer to update display after 1/10 second */
+	if (!timer_pending(&tp->timer))
+		tty3270_set_timer(tp, HZ/10);
+
+	spin_unlock_bh(&tp->view.lock);
+}
+
+/*
+ * String write routine for 3270 ttys
+ */
+static int
+tty3270_write(struct tty_struct * tty,
+	      const unsigned char *buf, int count)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return 0;
+	if (tp->char_count > 0) {
+		tty3270_do_write(tp, tty, tp->char_buf, tp->char_count);
+		tp->char_count = 0;
+	}
+	tty3270_do_write(tp, tty, buf, count);
+	return count;
+}
+
+/*
+ * Put single characters to the ttys character buffer
+ */
+static int tty3270_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp || tp->char_count >= TTY3270_CHAR_BUF_SIZE)
+		return 0;
+	tp->char_buf[tp->char_count++] = ch;
+	return 1;
+}
+
+/*
+ * Flush all characters from the ttys characeter buffer put there
+ * by tty3270_put_char.
+ */
+static void
+tty3270_flush_chars(struct tty_struct *tty)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return;
+	if (tp->char_count > 0) {
+		tty3270_do_write(tp, tty, tp->char_buf, tp->char_count);
+		tp->char_count = 0;
+	}
+}
+
+/*
+ * Returns the number of characters in the output buffer. This is
+ * used in tty_wait_until_sent to wait until all characters have
+ * appeared on the screen.
+ */
+static int
+tty3270_chars_in_buffer(struct tty_struct *tty)
+{
+	return 0;
+}
+
+static void
+tty3270_flush_buffer(struct tty_struct *tty)
+{
+}
+
+/*
+ * Check for visible/invisible input switches
+ */
+static void
+tty3270_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+	struct tty3270 *tp;
+	int new;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return;
+	spin_lock_bh(&tp->view.lock);
+	if (L_ICANON(tty)) {
+		new = L_ECHO(tty) ? TF_INPUT: TF_INPUTN;
+		if (new != tp->inattr) {
+			tp->inattr = new;
+			tty3270_update_prompt(tp, NULL, 0);
+			tty3270_set_timer(tp, 1);
+		}
+	}
+	spin_unlock_bh(&tp->view.lock);
+}
+
+/*
+ * Disable reading from a 3270 tty
+ */
+static void
+tty3270_throttle(struct tty_struct * tty)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return;
+	tp->throttle = 1;
+}
+
+/*
+ * Enable reading from a 3270 tty
+ */
+static void
+tty3270_unthrottle(struct tty_struct * tty)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return;
+	tp->throttle = 0;
+	if (tp->attn)
+		tty3270_issue_read(tp, 1);
+}
+
+/*
+ * Hang up the tty device.
+ */
+static void
+tty3270_hangup(struct tty_struct *tty)
+{
+	// FIXME: implement
+}
+
+static void
+tty3270_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+}
+
+static int tty3270_ioctl(struct tty_struct *tty, unsigned int cmd,
+			 unsigned long arg)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return -ENODEV;
+	if (tty->flags & (1 << TTY_IO_ERROR))
+		return -EIO;
+	return kbd_ioctl(tp->kbd, cmd, arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long tty3270_compat_ioctl(struct tty_struct *tty,
+				 unsigned int cmd, unsigned long arg)
+{
+	struct tty3270 *tp;
+
+	tp = tty->driver_data;
+	if (!tp)
+		return -ENODEV;
+	if (tty->flags & (1 << TTY_IO_ERROR))
+		return -EIO;
+	return kbd_ioctl(tp->kbd, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static const struct tty_operations tty3270_ops = {
+	.install = tty3270_install,
+	.cleanup = tty3270_cleanup,
+	.open = tty3270_open,
+	.close = tty3270_close,
+	.write = tty3270_write,
+	.put_char = tty3270_put_char,
+	.flush_chars = tty3270_flush_chars,
+	.write_room = tty3270_write_room,
+	.chars_in_buffer = tty3270_chars_in_buffer,
+	.flush_buffer = tty3270_flush_buffer,
+	.throttle = tty3270_throttle,
+	.unthrottle = tty3270_unthrottle,
+	.hangup = tty3270_hangup,
+	.wait_until_sent = tty3270_wait_until_sent,
+	.ioctl = tty3270_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = tty3270_compat_ioctl,
+#endif
+	.set_termios = tty3270_set_termios
+};
+
+static void tty3270_create_cb(int minor)
+{
+	tty_register_device(tty3270_driver, minor - RAW3270_FIRSTMINOR, NULL);
+}
+
+static void tty3270_destroy_cb(int minor)
+{
+	tty_unregister_device(tty3270_driver, minor - RAW3270_FIRSTMINOR);
+}
+
+static struct raw3270_notifier tty3270_notifier =
+{
+	.create = tty3270_create_cb,
+	.destroy = tty3270_destroy_cb,
+};
+
+/*
+ * 3270 tty registration code called from tty_init().
+ * Most kernel services (incl. kmalloc) are available at this poimt.
+ */
+static int __init tty3270_init(void)
+{
+	struct tty_driver *driver;
+	int ret;
+
+	driver = tty_alloc_driver(RAW3270_MAXDEVS,
+				  TTY_DRIVER_REAL_RAW |
+				  TTY_DRIVER_DYNAMIC_DEV |
+				  TTY_DRIVER_RESET_TERMIOS);
+	if (IS_ERR(driver))
+		return PTR_ERR(driver);
+
+	/*
+	 * Initialize the tty_driver structure
+	 * Entries in tty3270_driver that are NOT initialized:
+	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
+	 */
+	driver->driver_name = "tty3270";
+	driver->name = "3270/tty";
+	driver->major = IBM_TTY3270_MAJOR;
+	driver->minor_start = RAW3270_FIRSTMINOR;
+	driver->name_base = RAW3270_FIRSTMINOR;
+	driver->type = TTY_DRIVER_TYPE_SYSTEM;
+	driver->subtype = SYSTEM_TYPE_TTY;
+	driver->init_termios = tty_std_termios;
+	tty_set_operations(driver, &tty3270_ops);
+	ret = tty_register_driver(driver);
+	if (ret) {
+		put_tty_driver(driver);
+		return ret;
+	}
+	tty3270_driver = driver;
+	raw3270_register_notifier(&tty3270_notifier);
+	return 0;
+}
+
+static void __exit
+tty3270_exit(void)
+{
+	struct tty_driver *driver;
+
+	raw3270_unregister_notifier(&tty3270_notifier);
+	driver = tty3270_driver;
+	tty3270_driver = NULL;
+	tty_unregister_driver(driver);
+	put_tty_driver(driver);
+	tty3270_del_views();
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(IBM_TTY3270_MAJOR);
+
+module_init(tty3270_init);
+module_exit(tty3270_exit);