tty3270.c

linux-2.6.15.6

/*
 *  drivers/s390/char/tty3270.c
 *    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 <[e-mail]>
 *	-- Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
 */

#include <linux/config.h>
#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/slab.h>
#include <linux/bootmem.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/ebcdic.h>
#include <asm/uaccess.h>


#include "raw3270.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;

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_struct *tty;		/* Pointer to tty structure */
	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;

	/* 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		15

static void tty3270_update(struct tty3270 *);

/*
 * Setup timeout for a device. On timeout trigger an update.
 */
void
tty3270_set_timer(struct tty3270 *tp, int expires)
{
	if (expires == 0) {
		if (timer_pending(&tp->timer) && del_timer(&tp->timer))
			raw3270_put_view(&tp->view);
		return;
	}
	if (timer_pending(&tp->timer) &&
	    mod_timer(&tp->timer, jiffies + expires))
		return;
	raw3270_get_view(&tp->view);
	tp->timer.function = (void (*)(unsigned long)) tty3270_update;
	tp->timer.data = (unsigned long) tp;
	tp->timer.expires = jiffies + expires;
	add_timer(&tp->timer);
}

/*
 * 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;

	tp = (struct tty3270 *) rq->view;
	if (rq->rc != 0) {
		/* Write wasn't successfull. Refresh all. */
		tty3270_rebuild_update(tp);
		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_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);
	raw3270_put_view(&tp->view);
}

/*
 * Command recalling.
 */
static void
tty3270_rcl_add(struct tty3270 *tp, char *input, int len)
{
	struct string *s;

	tp->rcl_walk = 0;
	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;
	struct string *s;

	tp = kbd->tty->driver_data;
	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) : 0;
		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, 0, 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;

	tp = kbd->tty->driver_data;
	raw3270_deactivate_view(&tp->view);
}

/*
 * Scroll forward in history.
 */
static void
tty3270_scroll_forward(struct kbd_data *kbd)
{
	struct tty3270 *tp;
	int nr_up;

	tp = kbd->tty->driver_data;
	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;
	int nr_up;

	tp = kbd->tty->driver_data;
	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;
	char *input;
	int len;

	tp = (struct tty3270 *) rrq->view;
	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 = 0;
	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, 0, 0);
		tty3270_set_timer(tp, 1);
	} else if (tp->input->string[0] == 0x6d) {
		/* Display has been cleared. Redraw. */
		tty3270_rebuild_update(tp);
		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);

	/* Emit input string. */
	if (tp->tty) {
		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)
{
	raw3270_get_view(rq->view);
	/* Schedule tasklet to pass input to tty. */
	tasklet_schedule(&((struct tty3270 *) rq->view)->readlet);
}

/*
 * Issue a read request. Call with device lock.