xref: /linux/drivers/s390/char/con3215.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * 3215 line mode terminal driver.
3  *
4  * Copyright IBM Corp. 1999, 2009
5  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6  *
7  * Updated:
8  *  Aug-2000: Added tab support
9  *	      Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kdev_t.h>
15 #include <linux/tty.h>
16 #include <linux/tty_flip.h>
17 #include <linux/vt_kern.h>
18 #include <linux/init.h>
19 #include <linux/console.h>
20 #include <linux/interrupt.h>
21 #include <linux/err.h>
22 #include <linux/reboot.h>
23 #include <linux/serial.h> /* ASYNC_* flags */
24 #include <linux/slab.h>
25 #include <asm/ccwdev.h>
26 #include <asm/cio.h>
27 #include <asm/io.h>
28 #include <asm/ebcdic.h>
29 #include <asm/uaccess.h>
30 #include <asm/delay.h>
31 #include <asm/cpcmd.h>
32 #include <asm/setup.h>
33 
34 #include "ctrlchar.h"
35 
36 #define NR_3215		    1
37 #define NR_3215_REQ	    (4*NR_3215)
38 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
39 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
40 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
41 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
42 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
43 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
44 #define RAW3215_NR_CCWS	    3
45 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
46 
47 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
48 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
49 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
50 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
51 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
52 
53 #define TAB_STOP_SIZE	    8	      /* tab stop size */
54 
55 /*
56  * Request types for a 3215 device
57  */
58 enum raw3215_type {
59 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
60 };
61 
62 /*
63  * Request structure for a 3215 device
64  */
65 struct raw3215_req {
66 	enum raw3215_type type;	      /* type of the request */
67 	int start, len;		      /* start index & len in output buffer */
68 	int delayable;		      /* indication to wait for more data */
69 	int residual;		      /* residual count for read request */
70 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
71 	struct raw3215_info *info;    /* pointer to main structure */
72 	struct raw3215_req *next;     /* pointer to next request */
73 } __attribute__ ((aligned(8)));
74 
75 struct raw3215_info {
76 	struct tty_port port;
77 	struct ccw_device *cdev;      /* device for tty driver */
78 	spinlock_t *lock;	      /* pointer to irq lock */
79 	int flags;		      /* state flags */
80 	char *buffer;		      /* pointer to output buffer */
81 	char *inbuf;		      /* pointer to input buffer */
82 	int head;		      /* first free byte in output buffer */
83 	int count;		      /* number of bytes in output buffer */
84 	int written;		      /* number of bytes in write requests */
85 	struct raw3215_req *queued_read; /* pointer to queued read requests */
86 	struct raw3215_req *queued_write;/* pointer to queued write requests */
87 	struct tasklet_struct tlet;   /* tasklet to invoke tty_wakeup */
88 	wait_queue_head_t empty_wait; /* wait queue for flushing */
89 	struct timer_list timer;      /* timer for delayed output */
90 	int line_pos;		      /* position on the line (for tabs) */
91 	char ubuffer[80];	      /* copy_from_user buffer */
92 };
93 
94 /* array of 3215 devices structures */
95 static struct raw3215_info *raw3215[NR_3215];
96 /* spinlock to protect the raw3215 array */
97 static DEFINE_SPINLOCK(raw3215_device_lock);
98 /* list of free request structures */
99 static struct raw3215_req *raw3215_freelist;
100 /* spinlock to protect free list */
101 static spinlock_t raw3215_freelist_lock;
102 
103 static struct tty_driver *tty3215_driver;
104 
105 /*
106  * Get a request structure from the free list
107  */
108 static inline struct raw3215_req *raw3215_alloc_req(void)
109 {
110 	struct raw3215_req *req;
111 	unsigned long flags;
112 
113 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
114 	req = raw3215_freelist;
115 	raw3215_freelist = req->next;
116 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
117 	return req;
118 }
119 
120 /*
121  * Put a request structure back to the free list
122  */
123 static inline void raw3215_free_req(struct raw3215_req *req)
124 {
125 	unsigned long flags;
126 
127 	if (req->type == RAW3215_FREE)
128 		return;		/* don't free a free request */
129 	req->type = RAW3215_FREE;
130 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
131 	req->next = raw3215_freelist;
132 	raw3215_freelist = req;
133 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
134 }
135 
136 /*
137  * Set up a read request that reads up to 160 byte from the 3215 device.
138  * If there is a queued read request it is used, but that shouldn't happen
139  * because a 3215 terminal won't accept a new read before the old one is
140  * completed.
141  */
142 static void raw3215_mk_read_req(struct raw3215_info *raw)
143 {
144 	struct raw3215_req *req;
145 	struct ccw1 *ccw;
146 
147 	/* there can only be ONE read request at a time */
148 	req = raw->queued_read;
149 	if (req == NULL) {
150 		/* no queued read request, use new req structure */
151 		req = raw3215_alloc_req();
152 		req->type = RAW3215_READ;
153 		req->info = raw;
154 		raw->queued_read = req;
155 	}
156 
157 	ccw = req->ccws;
158 	ccw->cmd_code = 0x0A; /* read inquiry */
159 	ccw->flags = 0x20;    /* ignore incorrect length */
160 	ccw->count = 160;
161 	ccw->cda = (__u32) __pa(raw->inbuf);
162 }
163 
164 /*
165  * Set up a write request with the information from the main structure.
166  * A ccw chain is created that writes as much as possible from the output
167  * buffer to the 3215 device. If a queued write exists it is replaced by
168  * the new, probably lengthened request.
169  */
170 static void raw3215_mk_write_req(struct raw3215_info *raw)
171 {
172 	struct raw3215_req *req;
173 	struct ccw1 *ccw;
174 	int len, count, ix, lines;
175 
176 	if (raw->count <= raw->written)
177 		return;
178 	/* check if there is a queued write request */
179 	req = raw->queued_write;
180 	if (req == NULL) {
181 		/* no queued write request, use new req structure */
182 		req = raw3215_alloc_req();
183 		req->type = RAW3215_WRITE;
184 		req->info = raw;
185 		raw->queued_write = req;
186 	} else {
187 		raw->written -= req->len;
188 	}
189 
190 	ccw = req->ccws;
191 	req->start = (raw->head - raw->count + raw->written) &
192 		     (RAW3215_BUFFER_SIZE - 1);
193 	/*
194 	 * now we have to count newlines. We can at max accept
195 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
196 	 * a restriction in VM
197 	 */
198 	lines = 0;
199 	ix = req->start;
200 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
201 		if (raw->buffer[ix] == 0x15)
202 			lines++;
203 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
204 	}
205 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
206 	if (len > RAW3215_MAX_BYTES)
207 		len = RAW3215_MAX_BYTES;
208 	req->len = len;
209 	raw->written += len;
210 
211 	/* set the indication if we should try to enlarge this request */
212 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
213 
214 	ix = req->start;
215 	while (len > 0) {
216 		if (ccw > req->ccws)
217 			ccw[-1].flags |= 0x40; /* use command chaining */
218 		ccw->cmd_code = 0x01; /* write, auto carrier return */
219 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
220 		ccw->cda =
221 			(__u32) __pa(raw->buffer + ix);
222 		count = len;
223 		if (ix + count > RAW3215_BUFFER_SIZE)
224 			count = RAW3215_BUFFER_SIZE - ix;
225 		ccw->count = count;
226 		len -= count;
227 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
228 		ccw++;
229 	}
230 	/*
231 	 * Add a NOP to the channel program. 3215 devices are purely
232 	 * emulated and its much better to avoid the channel end
233 	 * interrupt in this case.
234 	 */
235 	if (ccw > req->ccws)
236 		ccw[-1].flags |= 0x40; /* use command chaining */
237 	ccw->cmd_code = 0x03; /* NOP */
238 	ccw->flags = 0;
239 	ccw->cda = 0;
240 	ccw->count = 1;
241 }
242 
243 /*
244  * Start a read or a write request
245  */
246 static void raw3215_start_io(struct raw3215_info *raw)
247 {
248 	struct raw3215_req *req;
249 	int res;
250 
251 	req = raw->queued_read;
252 	if (req != NULL &&
253 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
254 		/* dequeue request */
255 		raw->queued_read = NULL;
256 		res = ccw_device_start(raw->cdev, req->ccws,
257 				       (unsigned long) req, 0, 0);
258 		if (res != 0) {
259 			/* do_IO failed, put request back to queue */
260 			raw->queued_read = req;
261 		} else {
262 			raw->flags |= RAW3215_WORKING;
263 		}
264 	}
265 	req = raw->queued_write;
266 	if (req != NULL &&
267 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
268 		/* dequeue request */
269 		raw->queued_write = NULL;
270 		res = ccw_device_start(raw->cdev, req->ccws,
271 				       (unsigned long) req, 0, 0);
272 		if (res != 0) {
273 			/* do_IO failed, put request back to queue */
274 			raw->queued_write = req;
275 		} else {
276 			raw->flags |= RAW3215_WORKING;
277 		}
278 	}
279 }
280 
281 /*
282  * Function to start a delayed output after RAW3215_TIMEOUT seconds
283  */
284 static void raw3215_timeout(unsigned long __data)
285 {
286 	struct raw3215_info *raw = (struct raw3215_info *) __data;
287 	unsigned long flags;
288 
289 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
290 	if (raw->flags & RAW3215_TIMER_RUNS) {
291 		del_timer(&raw->timer);
292 		raw->flags &= ~RAW3215_TIMER_RUNS;
293 		if (!(raw->port.flags & ASYNC_SUSPENDED)) {
294 			raw3215_mk_write_req(raw);
295 			raw3215_start_io(raw);
296 		}
297 	}
298 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
299 }
300 
301 /*
302  * Function to conditionally start an IO. A read is started immediately,
303  * a write is only started immediately if the flush flag is on or the
304  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
305  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
306  */
307 static inline void raw3215_try_io(struct raw3215_info *raw)
308 {
309 	if (!(raw->port.flags & ASYNC_INITIALIZED) ||
310 			(raw->port.flags & ASYNC_SUSPENDED))
311 		return;
312 	if (raw->queued_read != NULL)
313 		raw3215_start_io(raw);
314 	else if (raw->queued_write != NULL) {
315 		if ((raw->queued_write->delayable == 0) ||
316 		    (raw->flags & RAW3215_FLUSHING)) {
317 			/* execute write requests bigger than minimum size */
318 			raw3215_start_io(raw);
319 			if (raw->flags & RAW3215_TIMER_RUNS) {
320 				del_timer(&raw->timer);
321 				raw->flags &= ~RAW3215_TIMER_RUNS;
322 			}
323 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
324 			/* delay small writes */
325 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
326 			add_timer(&raw->timer);
327 			raw->flags |= RAW3215_TIMER_RUNS;
328 		}
329 	}
330 }
331 
332 /*
333  * Call tty_wakeup from tasklet context
334  */
335 static void raw3215_wakeup(unsigned long data)
336 {
337 	struct raw3215_info *raw = (struct raw3215_info *) data;
338 	struct tty_struct *tty;
339 
340 	tty = tty_port_tty_get(&raw->port);
341 	if (tty) {
342 		tty_wakeup(tty);
343 		tty_kref_put(tty);
344 	}
345 }
346 
347 /*
348  * Try to start the next IO and wake up processes waiting on the tty.
349  */
350 static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
351 {
352 	raw3215_mk_write_req(raw);
353 	raw3215_try_io(raw);
354 	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
355 		tasklet_schedule(&raw->tlet);
356 }
357 
358 /*
359  * Interrupt routine, called from common io layer
360  */
361 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
362 			struct irb *irb)
363 {
364 	struct raw3215_info *raw;
365 	struct raw3215_req *req;
366 	struct tty_struct *tty;
367 	int cstat, dstat;
368 	int count;
369 
370 	raw = dev_get_drvdata(&cdev->dev);
371 	req = (struct raw3215_req *) intparm;
372 	tty = tty_port_tty_get(&raw->port);
373 	cstat = irb->scsw.cmd.cstat;
374 	dstat = irb->scsw.cmd.dstat;
375 	if (cstat != 0)
376 		raw3215_next_io(raw, tty);
377 	if (dstat & 0x01) { /* we got a unit exception */
378 		dstat &= ~0x01;	 /* we can ignore it */
379 	}
380 	switch (dstat) {
381 	case 0x80:
382 		if (cstat != 0)
383 			break;
384 		/* Attention interrupt, someone hit the enter key */
385 		raw3215_mk_read_req(raw);
386 		raw3215_next_io(raw, tty);
387 		break;
388 	case 0x08:
389 	case 0x0C:
390 		/* Channel end interrupt. */
391 		if ((raw = req->info) == NULL)
392 			goto put_tty;	     /* That shouldn't happen ... */
393 		if (req->type == RAW3215_READ) {
394 			/* store residual count, then wait for device end */
395 			req->residual = irb->scsw.cmd.count;
396 		}
397 		if (dstat == 0x08)
398 			break;
399 	case 0x04:
400 		/* Device end interrupt. */
401 		if ((raw = req->info) == NULL)
402 			goto put_tty;	     /* That shouldn't happen ... */
403 		if (req->type == RAW3215_READ && tty != NULL) {
404 			unsigned int cchar;
405 
406 			count = 160 - req->residual;
407 			EBCASC(raw->inbuf, count);
408 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
409 			switch (cchar & CTRLCHAR_MASK) {
410 			case CTRLCHAR_SYSRQ:
411 				break;
412 
413 			case CTRLCHAR_CTRL:
414 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
415 				tty_flip_buffer_push(tty);
416 				break;
417 
418 			case CTRLCHAR_NONE:
419 				if (count < 2 ||
420 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
421 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
422 					/* add the auto \n */
423 					raw->inbuf[count] = '\n';
424 					count++;
425 				} else
426 					count -= 2;
427 				tty_insert_flip_string(tty, raw->inbuf, count);
428 				tty_flip_buffer_push(tty);
429 				break;
430 			}
431 		} else if (req->type == RAW3215_WRITE) {
432 			raw->count -= req->len;
433 			raw->written -= req->len;
434 		}
435 		raw->flags &= ~RAW3215_WORKING;
436 		raw3215_free_req(req);
437 		/* check for empty wait */
438 		if (waitqueue_active(&raw->empty_wait) &&
439 		    raw->queued_write == NULL &&
440 		    raw->queued_read == NULL) {
441 			wake_up_interruptible(&raw->empty_wait);
442 		}
443 		raw3215_next_io(raw, tty);
444 		break;
445 	default:
446 		/* Strange interrupt, I'll do my best to clean up */
447 		if (req != NULL && req->type != RAW3215_FREE) {
448 			if (req->type == RAW3215_WRITE) {
449 				raw->count -= req->len;
450 				raw->written -= req->len;
451 			}
452 			raw->flags &= ~RAW3215_WORKING;
453 			raw3215_free_req(req);
454 		}
455 		raw3215_next_io(raw, tty);
456 	}
457 put_tty:
458 	tty_kref_put(tty);
459 }
460 
461 /*
462  * Drop the oldest line from the output buffer.
463  */
464 static void raw3215_drop_line(struct raw3215_info *raw)
465 {
466 	int ix;
467 	char ch;
468 
469 	BUG_ON(raw->written != 0);
470 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
471 	while (raw->count > 0) {
472 		ch = raw->buffer[ix];
473 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
474 		raw->count--;
475 		if (ch == 0x15)
476 			break;
477 	}
478 	raw->head = ix;
479 }
480 
481 /*
482  * Wait until length bytes are available int the output buffer.
483  * Has to be called with the s390irq lock held. Can be called
484  * disabled.
485  */
486 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
487 {
488 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
489 		/* While console is frozen for suspend we have no other
490 		 * choice but to drop message from the buffer to make
491 		 * room for even more messages. */
492 		if (raw->port.flags & ASYNC_SUSPENDED) {
493 			raw3215_drop_line(raw);
494 			continue;
495 		}
496 		/* there might be a request pending */
497 		raw->flags |= RAW3215_FLUSHING;
498 		raw3215_mk_write_req(raw);
499 		raw3215_try_io(raw);
500 		raw->flags &= ~RAW3215_FLUSHING;
501 #ifdef CONFIG_TN3215_CONSOLE
502 		wait_cons_dev();
503 #endif
504 		/* Enough room freed up ? */
505 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
506 			break;
507 		/* there might be another cpu waiting for the lock */
508 		spin_unlock(get_ccwdev_lock(raw->cdev));
509 		udelay(100);
510 		spin_lock(get_ccwdev_lock(raw->cdev));
511 	}
512 }
513 
514 /*
515  * String write routine for 3215 devices
516  */
517 static void raw3215_write(struct raw3215_info *raw, const char *str,
518 			  unsigned int length)
519 {
520 	unsigned long flags;
521 	int c, count;
522 
523 	while (length > 0) {
524 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
525 		count = (length > RAW3215_BUFFER_SIZE) ?
526 					     RAW3215_BUFFER_SIZE : length;
527 		length -= count;
528 
529 		raw3215_make_room(raw, count);
530 
531 		/* copy string to output buffer and convert it to EBCDIC */
532 		while (1) {
533 			c = min_t(int, count,
534 				  min(RAW3215_BUFFER_SIZE - raw->count,
535 				      RAW3215_BUFFER_SIZE - raw->head));
536 			if (c <= 0)
537 				break;
538 			memcpy(raw->buffer + raw->head, str, c);
539 			ASCEBC(raw->buffer + raw->head, c);
540 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
541 			raw->count += c;
542 			raw->line_pos += c;
543 			str += c;
544 			count -= c;
545 		}
546 		if (!(raw->flags & RAW3215_WORKING)) {
547 			raw3215_mk_write_req(raw);
548 			/* start or queue request */
549 			raw3215_try_io(raw);
550 		}
551 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
552 	}
553 }
554 
555 /*
556  * Put character routine for 3215 devices
557  */
558 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
559 {
560 	unsigned long flags;
561 	unsigned int length, i;
562 
563 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
564 	if (ch == '\t') {
565 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
566 		raw->line_pos += length;
567 		ch = ' ';
568 	} else if (ch == '\n') {
569 		length = 1;
570 		raw->line_pos = 0;
571 	} else {
572 		length = 1;
573 		raw->line_pos++;
574 	}
575 	raw3215_make_room(raw, length);
576 
577 	for (i = 0; i < length; i++) {
578 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
579 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
580 		raw->count++;
581 	}
582 	if (!(raw->flags & RAW3215_WORKING)) {
583 		raw3215_mk_write_req(raw);
584 		/* start or queue request */
585 		raw3215_try_io(raw);
586 	}
587 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
588 }
589 
590 /*
591  * Flush routine, it simply sets the flush flag and tries to start
592  * pending IO.
593  */
594 static void raw3215_flush_buffer(struct raw3215_info *raw)
595 {
596 	unsigned long flags;
597 
598 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
599 	if (raw->count > 0) {
600 		raw->flags |= RAW3215_FLUSHING;
601 		raw3215_try_io(raw);
602 		raw->flags &= ~RAW3215_FLUSHING;
603 	}
604 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
605 }
606 
607 /*
608  * Fire up a 3215 device.
609  */
610 static int raw3215_startup(struct raw3215_info *raw)
611 {
612 	unsigned long flags;
613 
614 	if (raw->port.flags & ASYNC_INITIALIZED)
615 		return 0;
616 	raw->line_pos = 0;
617 	raw->port.flags |= ASYNC_INITIALIZED;
618 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
619 	raw3215_try_io(raw);
620 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
621 
622 	return 0;
623 }
624 
625 /*
626  * Shutdown a 3215 device.
627  */
628 static void raw3215_shutdown(struct raw3215_info *raw)
629 {
630 	DECLARE_WAITQUEUE(wait, current);
631 	unsigned long flags;
632 
633 	if (!(raw->port.flags & ASYNC_INITIALIZED))
634 		return;
635 	/* Wait for outstanding requests, then free irq */
636 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
637 	if ((raw->flags & RAW3215_WORKING) ||
638 	    raw->queued_write != NULL ||
639 	    raw->queued_read != NULL) {
640 		raw->port.flags |= ASYNC_CLOSING;
641 		add_wait_queue(&raw->empty_wait, &wait);
642 		set_current_state(TASK_INTERRUPTIBLE);
643 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
644 		schedule();
645 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
646 		remove_wait_queue(&raw->empty_wait, &wait);
647 		set_current_state(TASK_RUNNING);
648 		raw->port.flags &= ~(ASYNC_INITIALIZED | ASYNC_CLOSING);
649 	}
650 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
651 }
652 
653 static struct raw3215_info *raw3215_alloc_info(void)
654 {
655 	struct raw3215_info *info;
656 
657 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
658 	if (!info)
659 		return NULL;
660 
661 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
662 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
663 	if (!info->buffer || !info->inbuf) {
664 		kfree(info);
665 		return NULL;
666 	}
667 
668 	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
669 	init_waitqueue_head(&info->empty_wait);
670 	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
671 	tty_port_init(&info->port);
672 
673 	return info;
674 }
675 
676 static void raw3215_free_info(struct raw3215_info *raw)
677 {
678 	kfree(raw->inbuf);
679 	kfree(raw->buffer);
680 	tty_port_destroy(&raw->port);
681 	kfree(raw);
682 }
683 
684 static int raw3215_probe (struct ccw_device *cdev)
685 {
686 	struct raw3215_info *raw;
687 	int line;
688 
689 	/* Console is special. */
690 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
691 		return 0;
692 
693 	raw = raw3215_alloc_info();
694 	if (raw == NULL)
695 		return -ENOMEM;
696 
697 	raw->cdev = cdev;
698 	dev_set_drvdata(&cdev->dev, raw);
699 	cdev->handler = raw3215_irq;
700 
701 	spin_lock(&raw3215_device_lock);
702 	for (line = 0; line < NR_3215; line++) {
703 		if (!raw3215[line]) {
704 			raw3215[line] = raw;
705 			break;
706 		}
707 	}
708 	spin_unlock(&raw3215_device_lock);
709 	if (line == NR_3215) {
710 		raw3215_free_info(raw);
711 		return -ENODEV;
712 	}
713 
714 	return 0;
715 }
716 
717 static void raw3215_remove (struct ccw_device *cdev)
718 {
719 	struct raw3215_info *raw;
720 	unsigned int line;
721 
722 	ccw_device_set_offline(cdev);
723 	raw = dev_get_drvdata(&cdev->dev);
724 	if (raw) {
725 		spin_lock(&raw3215_device_lock);
726 		for (line = 0; line < NR_3215; line++)
727 			if (raw3215[line] == raw)
728 				break;
729 		raw3215[line] = NULL;
730 		spin_unlock(&raw3215_device_lock);
731 		dev_set_drvdata(&cdev->dev, NULL);
732 		raw3215_free_info(raw);
733 	}
734 }
735 
736 static int raw3215_set_online (struct ccw_device *cdev)
737 {
738 	struct raw3215_info *raw;
739 
740 	raw = dev_get_drvdata(&cdev->dev);
741 	if (!raw)
742 		return -ENODEV;
743 
744 	return raw3215_startup(raw);
745 }
746 
747 static int raw3215_set_offline (struct ccw_device *cdev)
748 {
749 	struct raw3215_info *raw;
750 
751 	raw = dev_get_drvdata(&cdev->dev);
752 	if (!raw)
753 		return -ENODEV;
754 
755 	raw3215_shutdown(raw);
756 
757 	return 0;
758 }
759 
760 static int raw3215_pm_stop(struct ccw_device *cdev)
761 {
762 	struct raw3215_info *raw;
763 	unsigned long flags;
764 
765 	/* Empty the output buffer, then prevent new I/O. */
766 	raw = dev_get_drvdata(&cdev->dev);
767 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
768 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
769 	raw->port.flags |= ASYNC_SUSPENDED;
770 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
771 	return 0;
772 }
773 
774 static int raw3215_pm_start(struct ccw_device *cdev)
775 {
776 	struct raw3215_info *raw;
777 	unsigned long flags;
778 
779 	/* Allow I/O again and flush output buffer. */
780 	raw = dev_get_drvdata(&cdev->dev);
781 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
782 	raw->port.flags &= ~ASYNC_SUSPENDED;
783 	raw->flags |= RAW3215_FLUSHING;
784 	raw3215_try_io(raw);
785 	raw->flags &= ~RAW3215_FLUSHING;
786 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
787 	return 0;
788 }
789 
790 static struct ccw_device_id raw3215_id[] = {
791 	{ CCW_DEVICE(0x3215, 0) },
792 	{ /* end of list */ },
793 };
794 
795 static struct ccw_driver raw3215_ccw_driver = {
796 	.driver = {
797 		.name	= "3215",
798 		.owner	= THIS_MODULE,
799 	},
800 	.ids		= raw3215_id,
801 	.probe		= &raw3215_probe,
802 	.remove		= &raw3215_remove,
803 	.set_online	= &raw3215_set_online,
804 	.set_offline	= &raw3215_set_offline,
805 	.freeze		= &raw3215_pm_stop,
806 	.thaw		= &raw3215_pm_start,
807 	.restore	= &raw3215_pm_start,
808 	.int_class	= IOINT_C15,
809 };
810 
811 #ifdef CONFIG_TN3215_CONSOLE
812 /*
813  * Write a string to the 3215 console
814  */
815 static void con3215_write(struct console *co, const char *str,
816 			  unsigned int count)
817 {
818 	struct raw3215_info *raw;
819 	int i;
820 
821 	if (count <= 0)
822 		return;
823 	raw = raw3215[0];	/* console 3215 is the first one */
824 	while (count > 0) {
825 		for (i = 0; i < count; i++)
826 			if (str[i] == '\t' || str[i] == '\n')
827 				break;
828 		raw3215_write(raw, str, i);
829 		count -= i;
830 		str += i;
831 		if (count > 0) {
832 			raw3215_putchar(raw, *str);
833 			count--;
834 			str++;
835 		}
836 	}
837 }
838 
839 static struct tty_driver *con3215_device(struct console *c, int *index)
840 {
841 	*index = c->index;
842 	return tty3215_driver;
843 }
844 
845 /*
846  * panic() calls con3215_flush through a panic_notifier
847  * before the system enters a disabled, endless loop.
848  */
849 static void con3215_flush(void)
850 {
851 	struct raw3215_info *raw;
852 	unsigned long flags;
853 
854 	raw = raw3215[0];  /* console 3215 is the first one */
855 	if (raw->port.flags & ASYNC_SUSPENDED)
856 		/* The console is still frozen for suspend. */
857 		if (ccw_device_force_console())
858 			/* Forcing didn't work, no panic message .. */
859 			return;
860 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
861 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
862 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
863 }
864 
865 static int con3215_notify(struct notifier_block *self,
866 			  unsigned long event, void *data)
867 {
868 	con3215_flush();
869 	return NOTIFY_OK;
870 }
871 
872 static struct notifier_block on_panic_nb = {
873 	.notifier_call = con3215_notify,
874 	.priority = 0,
875 };
876 
877 static struct notifier_block on_reboot_nb = {
878 	.notifier_call = con3215_notify,
879 	.priority = 0,
880 };
881 
882 /*
883  *  The console structure for the 3215 console
884  */
885 static struct console con3215 = {
886 	.name	 = "ttyS",
887 	.write	 = con3215_write,
888 	.device	 = con3215_device,
889 	.flags	 = CON_PRINTBUFFER,
890 };
891 
892 /*
893  * 3215 console initialization code called from console_init().
894  */
895 static int __init con3215_init(void)
896 {
897 	struct ccw_device *cdev;
898 	struct raw3215_info *raw;
899 	struct raw3215_req *req;
900 	int i;
901 
902 	/* Check if 3215 is to be the console */
903 	if (!CONSOLE_IS_3215)
904 		return -ENODEV;
905 
906 	/* Set the console mode for VM */
907 	if (MACHINE_IS_VM) {
908 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
909 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
910 	}
911 
912 	/* allocate 3215 request structures */
913 	raw3215_freelist = NULL;
914 	spin_lock_init(&raw3215_freelist_lock);
915 	for (i = 0; i < NR_3215_REQ; i++) {
916 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
917 		req->next = raw3215_freelist;
918 		raw3215_freelist = req;
919 	}
920 
921 	cdev = ccw_device_probe_console();
922 	if (IS_ERR(cdev))
923 		return -ENODEV;
924 
925 	raw3215[0] = raw = raw3215_alloc_info();
926 	raw->cdev = cdev;
927 	dev_set_drvdata(&cdev->dev, raw);
928 	cdev->handler = raw3215_irq;
929 
930 	/* Request the console irq */
931 	if (raw3215_startup(raw) != 0) {
932 		raw3215_free_info(raw);
933 		raw3215[0] = NULL;
934 		return -ENODEV;
935 	}
936 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
937 	register_reboot_notifier(&on_reboot_nb);
938 	register_console(&con3215);
939 	return 0;
940 }
941 console_initcall(con3215_init);
942 #endif
943 
944 static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
945 {
946 	struct raw3215_info *raw;
947 
948 	raw = raw3215[tty->index];
949 	if (raw == NULL)
950 		return -ENODEV;
951 
952 	tty->driver_data = raw;
953 
954 	return tty_port_install(&raw->port, driver, tty);
955 }
956 
957 /*
958  * tty3215_open
959  *
960  * This routine is called whenever a 3215 tty is opened.
961  */
962 static int tty3215_open(struct tty_struct *tty, struct file * filp)
963 {
964 	struct raw3215_info *raw = tty->driver_data;
965 	int retval;
966 
967 	tty_port_tty_set(&raw->port, tty);
968 
969 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
970 	/*
971 	 * Start up 3215 device
972 	 */
973 	retval = raw3215_startup(raw);
974 	if (retval)
975 		return retval;
976 
977 	return 0;
978 }
979 
980 /*
981  * tty3215_close()
982  *
983  * This routine is called when the 3215 tty is closed. We wait
984  * for the remaining request to be completed. Then we clean up.
985  */
986 static void tty3215_close(struct tty_struct *tty, struct file * filp)
987 {
988 	struct raw3215_info *raw;
989 
990 	raw = (struct raw3215_info *) tty->driver_data;
991 	if (raw == NULL || tty->count > 1)
992 		return;
993 	tty->closing = 1;
994 	/* Shutdown the terminal */
995 	raw3215_shutdown(raw);
996 	tasklet_kill(&raw->tlet);
997 	tty->closing = 0;
998 	tty_port_tty_set(&raw->port, NULL);
999 }
1000 
1001 /*
1002  * Returns the amount of free space in the output buffer.
1003  */
1004 static int tty3215_write_room(struct tty_struct *tty)
1005 {
1006 	struct raw3215_info *raw;
1007 
1008 	raw = (struct raw3215_info *) tty->driver_data;
1009 
1010 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1011 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1012 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1013 	else
1014 		return 0;
1015 }
1016 
1017 /*
1018  * String write routine for 3215 ttys
1019  */
1020 static int tty3215_write(struct tty_struct * tty,
1021 			 const unsigned char *buf, int count)
1022 {
1023 	struct raw3215_info *raw;
1024 
1025 	if (!tty)
1026 		return 0;
1027 	raw = (struct raw3215_info *) tty->driver_data;
1028 	raw3215_write(raw, buf, count);
1029 	return count;
1030 }
1031 
1032 /*
1033  * Put character routine for 3215 ttys
1034  */
1035 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1036 {
1037 	struct raw3215_info *raw;
1038 
1039 	if (!tty)
1040 		return 0;
1041 	raw = (struct raw3215_info *) tty->driver_data;
1042 	raw3215_putchar(raw, ch);
1043 	return 1;
1044 }
1045 
1046 static void tty3215_flush_chars(struct tty_struct *tty)
1047 {
1048 }
1049 
1050 /*
1051  * Returns the number of characters in the output buffer
1052  */
1053 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1054 {
1055 	struct raw3215_info *raw;
1056 
1057 	raw = (struct raw3215_info *) tty->driver_data;
1058 	return raw->count;
1059 }
1060 
1061 static void tty3215_flush_buffer(struct tty_struct *tty)
1062 {
1063 	struct raw3215_info *raw;
1064 
1065 	raw = (struct raw3215_info *) tty->driver_data;
1066 	raw3215_flush_buffer(raw);
1067 	tty_wakeup(tty);
1068 }
1069 
1070 /*
1071  * Disable reading from a 3215 tty
1072  */
1073 static void tty3215_throttle(struct tty_struct * tty)
1074 {
1075 	struct raw3215_info *raw;
1076 
1077 	raw = (struct raw3215_info *) tty->driver_data;
1078 	raw->flags |= RAW3215_THROTTLED;
1079 }
1080 
1081 /*
1082  * Enable reading from a 3215 tty
1083  */
1084 static void tty3215_unthrottle(struct tty_struct * tty)
1085 {
1086 	struct raw3215_info *raw;
1087 	unsigned long flags;
1088 
1089 	raw = (struct raw3215_info *) tty->driver_data;
1090 	if (raw->flags & RAW3215_THROTTLED) {
1091 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1092 		raw->flags &= ~RAW3215_THROTTLED;
1093 		raw3215_try_io(raw);
1094 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1095 	}
1096 }
1097 
1098 /*
1099  * Disable writing to a 3215 tty
1100  */
1101 static void tty3215_stop(struct tty_struct *tty)
1102 {
1103 	struct raw3215_info *raw;
1104 
1105 	raw = (struct raw3215_info *) tty->driver_data;
1106 	raw->flags |= RAW3215_STOPPED;
1107 }
1108 
1109 /*
1110  * Enable writing to a 3215 tty
1111  */
1112 static void tty3215_start(struct tty_struct *tty)
1113 {
1114 	struct raw3215_info *raw;
1115 	unsigned long flags;
1116 
1117 	raw = (struct raw3215_info *) tty->driver_data;
1118 	if (raw->flags & RAW3215_STOPPED) {
1119 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1120 		raw->flags &= ~RAW3215_STOPPED;
1121 		raw3215_try_io(raw);
1122 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1123 	}
1124 }
1125 
1126 static const struct tty_operations tty3215_ops = {
1127 	.install = tty3215_install,
1128 	.open = tty3215_open,
1129 	.close = tty3215_close,
1130 	.write = tty3215_write,
1131 	.put_char = tty3215_put_char,
1132 	.flush_chars = tty3215_flush_chars,
1133 	.write_room = tty3215_write_room,
1134 	.chars_in_buffer = tty3215_chars_in_buffer,
1135 	.flush_buffer = tty3215_flush_buffer,
1136 	.throttle = tty3215_throttle,
1137 	.unthrottle = tty3215_unthrottle,
1138 	.stop = tty3215_stop,
1139 	.start = tty3215_start,
1140 };
1141 
1142 /*
1143  * 3215 tty registration code called from tty_init().
1144  * Most kernel services (incl. kmalloc) are available at this poimt.
1145  */
1146 static int __init tty3215_init(void)
1147 {
1148 	struct tty_driver *driver;
1149 	int ret;
1150 
1151 	if (!CONSOLE_IS_3215)
1152 		return 0;
1153 
1154 	driver = alloc_tty_driver(NR_3215);
1155 	if (!driver)
1156 		return -ENOMEM;
1157 
1158 	ret = ccw_driver_register(&raw3215_ccw_driver);
1159 	if (ret) {
1160 		put_tty_driver(driver);
1161 		return ret;
1162 	}
1163 	/*
1164 	 * Initialize the tty_driver structure
1165 	 * Entries in tty3215_driver that are NOT initialized:
1166 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1167 	 */
1168 
1169 	driver->driver_name = "tty3215";
1170 	driver->name = "ttyS";
1171 	driver->major = TTY_MAJOR;
1172 	driver->minor_start = 64;
1173 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1174 	driver->subtype = SYSTEM_TYPE_TTY;
1175 	driver->init_termios = tty_std_termios;
1176 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1177 	driver->init_termios.c_oflag = ONLCR | XTABS;
1178 	driver->init_termios.c_lflag = ISIG;
1179 	driver->flags = TTY_DRIVER_REAL_RAW;
1180 	tty_set_operations(driver, &tty3215_ops);
1181 	ret = tty_register_driver(driver);
1182 	if (ret) {
1183 		put_tty_driver(driver);
1184 		return ret;
1185 	}
1186 	tty3215_driver = driver;
1187 	return 0;
1188 }
1189 
1190 static void __exit tty3215_exit(void)
1191 {
1192 	tty_unregister_driver(tty3215_driver);
1193 	put_tty_driver(tty3215_driver);
1194 	ccw_driver_unregister(&raw3215_ccw_driver);
1195 }
1196 
1197 module_init(tty3215_init);
1198 module_exit(tty3215_exit);
1199