xref: /openbmc/linux/drivers/s390/char/con3215.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * 3215 line mode terminal driver.
4  *
5  * Copyright IBM Corp. 1999, 2009
6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7  *
8  * Updated:
9  *  Aug-2000: Added tab support
10  *	      Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>
11  */
12 
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 <linux/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_FIXED	    1	      /* 3215 console device is not be freed */
48 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
49 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
50 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
51 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
52 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
53 
54 #define TAB_STOP_SIZE	    8	      /* tab stop size */
55 
56 /*
57  * Request types for a 3215 device
58  */
59 enum raw3215_type {
60 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
61 };
62 
63 /*
64  * Request structure for a 3215 device
65  */
66 struct raw3215_req {
67 	enum raw3215_type type;	      /* type of the request */
68 	int start, len;		      /* start index & len in output buffer */
69 	int delayable;		      /* indication to wait for more data */
70 	int residual;		      /* residual count for read request */
71 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
72 	struct raw3215_info *info;    /* pointer to main structure */
73 	struct raw3215_req *next;     /* pointer to next request */
74 } __attribute__ ((aligned(8)));
75 
76 struct raw3215_info {
77 	struct tty_port port;
78 	struct ccw_device *cdev;      /* device for tty driver */
79 	spinlock_t *lock;	      /* pointer to irq lock */
80 	int flags;		      /* state flags */
81 	char *buffer;		      /* pointer to output buffer */
82 	char *inbuf;		      /* pointer to input buffer */
83 	int head;		      /* first free byte in output buffer */
84 	int count;		      /* number of bytes in output buffer */
85 	int written;		      /* number of bytes in write requests */
86 	struct raw3215_req *queued_read; /* pointer to queued read requests */
87 	struct raw3215_req *queued_write;/* pointer to queued write requests */
88 	struct tasklet_struct tlet;   /* tasklet to invoke tty_wakeup */
89 	wait_queue_head_t empty_wait; /* wait queue for flushing */
90 	struct timer_list timer;      /* timer for delayed output */
91 	int line_pos;		      /* position on the line (for tabs) */
92 	char ubuffer[80];	      /* copy_from_user buffer */
93 };
94 
95 /* array of 3215 devices structures */
96 static struct raw3215_info *raw3215[NR_3215];
97 /* spinlock to protect the raw3215 array */
98 static DEFINE_SPINLOCK(raw3215_device_lock);
99 /* list of free request structures */
100 static struct raw3215_req *raw3215_freelist;
101 /* spinlock to protect free list */
102 static spinlock_t raw3215_freelist_lock;
103 
104 static struct tty_driver *tty3215_driver;
105 
106 /*
107  * Get a request structure from the free list
108  */
109 static inline struct raw3215_req *raw3215_alloc_req(void)
110 {
111 	struct raw3215_req *req;
112 	unsigned long flags;
113 
114 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
115 	req = raw3215_freelist;
116 	raw3215_freelist = req->next;
117 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
118 	return req;
119 }
120 
121 /*
122  * Put a request structure back to the free list
123  */
124 static inline void raw3215_free_req(struct raw3215_req *req)
125 {
126 	unsigned long flags;
127 
128 	if (req->type == RAW3215_FREE)
129 		return;		/* don't free a free request */
130 	req->type = RAW3215_FREE;
131 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
132 	req->next = raw3215_freelist;
133 	raw3215_freelist = req;
134 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
135 }
136 
137 /*
138  * Set up a read request that reads up to 160 byte from the 3215 device.
139  * If there is a queued read request it is used, but that shouldn't happen
140  * because a 3215 terminal won't accept a new read before the old one is
141  * completed.
142  */
143 static void raw3215_mk_read_req(struct raw3215_info *raw)
144 {
145 	struct raw3215_req *req;
146 	struct ccw1 *ccw;
147 
148 	/* there can only be ONE read request at a time */
149 	req = raw->queued_read;
150 	if (req == NULL) {
151 		/* no queued read request, use new req structure */
152 		req = raw3215_alloc_req();
153 		req->type = RAW3215_READ;
154 		req->info = raw;
155 		raw->queued_read = req;
156 	}
157 
158 	ccw = req->ccws;
159 	ccw->cmd_code = 0x0A; /* read inquiry */
160 	ccw->flags = 0x20;    /* ignore incorrect length */
161 	ccw->count = 160;
162 	ccw->cda = (__u32) __pa(raw->inbuf);
163 }
164 
165 /*
166  * Set up a write request with the information from the main structure.
167  * A ccw chain is created that writes as much as possible from the output
168  * buffer to the 3215 device. If a queued write exists it is replaced by
169  * the new, probably lengthened request.
170  */
171 static void raw3215_mk_write_req(struct raw3215_info *raw)
172 {
173 	struct raw3215_req *req;
174 	struct ccw1 *ccw;
175 	int len, count, ix, lines;
176 
177 	if (raw->count <= raw->written)
178 		return;
179 	/* check if there is a queued write request */
180 	req = raw->queued_write;
181 	if (req == NULL) {
182 		/* no queued write request, use new req structure */
183 		req = raw3215_alloc_req();
184 		req->type = RAW3215_WRITE;
185 		req->info = raw;
186 		raw->queued_write = req;
187 	} else {
188 		raw->written -= req->len;
189 	}
190 
191 	ccw = req->ccws;
192 	req->start = (raw->head - raw->count + raw->written) &
193 		     (RAW3215_BUFFER_SIZE - 1);
194 	/*
195 	 * now we have to count newlines. We can at max accept
196 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
197 	 * a restriction in VM
198 	 */
199 	lines = 0;
200 	ix = req->start;
201 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
202 		if (raw->buffer[ix] == 0x15)
203 			lines++;
204 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
205 	}
206 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
207 	if (len > RAW3215_MAX_BYTES)
208 		len = RAW3215_MAX_BYTES;
209 	req->len = len;
210 	raw->written += len;
211 
212 	/* set the indication if we should try to enlarge this request */
213 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
214 
215 	ix = req->start;
216 	while (len > 0) {
217 		if (ccw > req->ccws)
218 			ccw[-1].flags |= 0x40; /* use command chaining */
219 		ccw->cmd_code = 0x01; /* write, auto carrier return */
220 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
221 		ccw->cda =
222 			(__u32) __pa(raw->buffer + ix);
223 		count = len;
224 		if (ix + count > RAW3215_BUFFER_SIZE)
225 			count = RAW3215_BUFFER_SIZE - ix;
226 		ccw->count = count;
227 		len -= count;
228 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
229 		ccw++;
230 	}
231 	/*
232 	 * Add a NOP to the channel program. 3215 devices are purely
233 	 * emulated and its much better to avoid the channel end
234 	 * interrupt in this case.
235 	 */
236 	if (ccw > req->ccws)
237 		ccw[-1].flags |= 0x40; /* use command chaining */
238 	ccw->cmd_code = 0x03; /* NOP */
239 	ccw->flags = 0;
240 	ccw->cda = 0;
241 	ccw->count = 1;
242 }
243 
244 /*
245  * Start a read or a write request
246  */
247 static void raw3215_start_io(struct raw3215_info *raw)
248 {
249 	struct raw3215_req *req;
250 	int res;
251 
252 	req = raw->queued_read;
253 	if (req != NULL &&
254 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
255 		/* dequeue request */
256 		raw->queued_read = NULL;
257 		res = ccw_device_start(raw->cdev, req->ccws,
258 				       (unsigned long) req, 0, 0);
259 		if (res != 0) {
260 			/* do_IO failed, put request back to queue */
261 			raw->queued_read = req;
262 		} else {
263 			raw->flags |= RAW3215_WORKING;
264 		}
265 	}
266 	req = raw->queued_write;
267 	if (req != NULL &&
268 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
269 		/* dequeue request */
270 		raw->queued_write = NULL;
271 		res = ccw_device_start(raw->cdev, req->ccws,
272 				       (unsigned long) req, 0, 0);
273 		if (res != 0) {
274 			/* do_IO failed, put request back to queue */
275 			raw->queued_write = req;
276 		} else {
277 			raw->flags |= RAW3215_WORKING;
278 		}
279 	}
280 }
281 
282 /*
283  * Function to start a delayed output after RAW3215_TIMEOUT seconds
284  */
285 static void raw3215_timeout(struct timer_list *t)
286 {
287 	struct raw3215_info *raw = from_timer(raw, t, timer);
288 	unsigned long flags;
289 
290 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
291 	raw->flags &= ~RAW3215_TIMER_RUNS;
292 	if (!tty_port_suspended(&raw->port)) {
293 		raw3215_mk_write_req(raw);
294 		raw3215_start_io(raw);
295 		if ((raw->queued_read || raw->queued_write) &&
296 		    !(raw->flags & RAW3215_WORKING) &&
297 		    !(raw->flags & RAW3215_TIMER_RUNS)) {
298 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
299 			add_timer(&raw->timer);
300 			raw->flags |= RAW3215_TIMER_RUNS;
301 		}
302 	}
303 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
304 }
305 
306 /*
307  * Function to conditionally start an IO. A read is started immediately,
308  * a write is only started immediately if the flush flag is on or the
309  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
310  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
311  */
312 static inline void raw3215_try_io(struct raw3215_info *raw)
313 {
314 	if (!tty_port_initialized(&raw->port) || tty_port_suspended(&raw->port))
315 		return;
316 	if (raw->queued_read != NULL)
317 		raw3215_start_io(raw);
318 	else if (raw->queued_write != NULL) {
319 		if ((raw->queued_write->delayable == 0) ||
320 		    (raw->flags & RAW3215_FLUSHING)) {
321 			/* execute write requests bigger than minimum size */
322 			raw3215_start_io(raw);
323 		}
324 	}
325 	if ((raw->queued_read || raw->queued_write) &&
326 	    !(raw->flags & RAW3215_WORKING) &&
327 	    !(raw->flags & RAW3215_TIMER_RUNS)) {
328 		raw->timer.expires = RAW3215_TIMEOUT + jiffies;
329 		add_timer(&raw->timer);
330 		raw->flags |= RAW3215_TIMER_RUNS;
331 	}
332 }
333 
334 /*
335  * Call tty_wakeup from tasklet context
336  */
337 static void raw3215_wakeup(unsigned long data)
338 {
339 	struct raw3215_info *raw = (struct raw3215_info *) data;
340 	struct tty_struct *tty;
341 
342 	tty = tty_port_tty_get(&raw->port);
343 	if (tty) {
344 		tty_wakeup(tty);
345 		tty_kref_put(tty);
346 	}
347 }
348 
349 /*
350  * Try to start the next IO and wake up processes waiting on the tty.
351  */
352 static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
353 {
354 	raw3215_mk_write_req(raw);
355 	raw3215_try_io(raw);
356 	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
357 		tasklet_schedule(&raw->tlet);
358 }
359 
360 /*
361  * Interrupt routine, called from common io layer
362  */
363 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
364 			struct irb *irb)
365 {
366 	struct raw3215_info *raw;
367 	struct raw3215_req *req;
368 	struct tty_struct *tty;
369 	int cstat, dstat;
370 	int count;
371 
372 	raw = dev_get_drvdata(&cdev->dev);
373 	req = (struct raw3215_req *) intparm;
374 	tty = tty_port_tty_get(&raw->port);
375 	cstat = irb->scsw.cmd.cstat;
376 	dstat = irb->scsw.cmd.dstat;
377 	if (cstat != 0)
378 		raw3215_next_io(raw, tty);
379 	if (dstat & 0x01) { /* we got a unit exception */
380 		dstat &= ~0x01;	 /* we can ignore it */
381 	}
382 	switch (dstat) {
383 	case 0x80:
384 		if (cstat != 0)
385 			break;
386 		/* Attention interrupt, someone hit the enter key */
387 		raw3215_mk_read_req(raw);
388 		raw3215_next_io(raw, tty);
389 		break;
390 	case 0x08:
391 	case 0x0C:
392 		/* Channel end interrupt. */
393 		if ((raw = req->info) == NULL)
394 			goto put_tty;	     /* That shouldn't happen ... */
395 		if (req->type == RAW3215_READ) {
396 			/* store residual count, then wait for device end */
397 			req->residual = irb->scsw.cmd.count;
398 		}
399 		if (dstat == 0x08)
400 			break;
401 	case 0x04:
402 		/* Device end interrupt. */
403 		if ((raw = req->info) == NULL)
404 			goto put_tty;	     /* That shouldn't happen ... */
405 		if (req->type == RAW3215_READ && tty != NULL) {
406 			unsigned int cchar;
407 
408 			count = 160 - req->residual;
409 			EBCASC(raw->inbuf, count);
410 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
411 			switch (cchar & CTRLCHAR_MASK) {
412 			case CTRLCHAR_SYSRQ:
413 				break;
414 
415 			case CTRLCHAR_CTRL:
416 				tty_insert_flip_char(&raw->port, cchar,
417 						TTY_NORMAL);
418 				tty_flip_buffer_push(&raw->port);
419 				break;
420 
421 			case CTRLCHAR_NONE:
422 				if (count < 2 ||
423 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
424 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
425 					/* add the auto \n */
426 					raw->inbuf[count] = '\n';
427 					count++;
428 				} else
429 					count -= 2;
430 				tty_insert_flip_string(&raw->port, raw->inbuf,
431 						count);
432 				tty_flip_buffer_push(&raw->port);
433 				break;
434 			}
435 		} else if (req->type == RAW3215_WRITE) {
436 			raw->count -= req->len;
437 			raw->written -= req->len;
438 		}
439 		raw->flags &= ~RAW3215_WORKING;
440 		raw3215_free_req(req);
441 		/* check for empty wait */
442 		if (waitqueue_active(&raw->empty_wait) &&
443 		    raw->queued_write == NULL &&
444 		    raw->queued_read == NULL) {
445 			wake_up_interruptible(&raw->empty_wait);
446 		}
447 		raw3215_next_io(raw, tty);
448 		break;
449 	default:
450 		/* Strange interrupt, I'll do my best to clean up */
451 		if (req != NULL && req->type != RAW3215_FREE) {
452 			if (req->type == RAW3215_WRITE) {
453 				raw->count -= req->len;
454 				raw->written -= req->len;
455 			}
456 			raw->flags &= ~RAW3215_WORKING;
457 			raw3215_free_req(req);
458 		}
459 		raw3215_next_io(raw, tty);
460 	}
461 put_tty:
462 	tty_kref_put(tty);
463 }
464 
465 /*
466  * Drop the oldest line from the output buffer.
467  */
468 static void raw3215_drop_line(struct raw3215_info *raw)
469 {
470 	int ix;
471 	char ch;
472 
473 	BUG_ON(raw->written != 0);
474 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
475 	while (raw->count > 0) {
476 		ch = raw->buffer[ix];
477 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
478 		raw->count--;
479 		if (ch == 0x15)
480 			break;
481 	}
482 	raw->head = ix;
483 }
484 
485 /*
486  * Wait until length bytes are available int the output buffer.
487  * Has to be called with the s390irq lock held. Can be called
488  * disabled.
489  */
490 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
491 {
492 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
493 		/* While console is frozen for suspend we have no other
494 		 * choice but to drop message from the buffer to make
495 		 * room for even more messages. */
496 		if (tty_port_suspended(&raw->port)) {
497 			raw3215_drop_line(raw);
498 			continue;
499 		}
500 		/* there might be a request pending */
501 		raw->flags |= RAW3215_FLUSHING;
502 		raw3215_mk_write_req(raw);
503 		raw3215_try_io(raw);
504 		raw->flags &= ~RAW3215_FLUSHING;
505 #ifdef CONFIG_TN3215_CONSOLE
506 		ccw_device_wait_idle(raw->cdev);
507 #endif
508 		/* Enough room freed up ? */
509 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
510 			break;
511 		/* there might be another cpu waiting for the lock */
512 		spin_unlock(get_ccwdev_lock(raw->cdev));
513 		udelay(100);
514 		spin_lock(get_ccwdev_lock(raw->cdev));
515 	}
516 }
517 
518 /*
519  * String write routine for 3215 devices
520  */
521 static void raw3215_write(struct raw3215_info *raw, const char *str,
522 			  unsigned int length)
523 {
524 	unsigned long flags;
525 	int c, count;
526 
527 	while (length > 0) {
528 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
529 		count = (length > RAW3215_BUFFER_SIZE) ?
530 					     RAW3215_BUFFER_SIZE : length;
531 		length -= count;
532 
533 		raw3215_make_room(raw, count);
534 
535 		/* copy string to output buffer and convert it to EBCDIC */
536 		while (1) {
537 			c = min_t(int, count,
538 				  min(RAW3215_BUFFER_SIZE - raw->count,
539 				      RAW3215_BUFFER_SIZE - raw->head));
540 			if (c <= 0)
541 				break;
542 			memcpy(raw->buffer + raw->head, str, c);
543 			ASCEBC(raw->buffer + raw->head, c);
544 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
545 			raw->count += c;
546 			raw->line_pos += c;
547 			str += c;
548 			count -= c;
549 		}
550 		if (!(raw->flags & RAW3215_WORKING)) {
551 			raw3215_mk_write_req(raw);
552 			/* start or queue request */
553 			raw3215_try_io(raw);
554 		}
555 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
556 	}
557 }
558 
559 /*
560  * Put character routine for 3215 devices
561  */
562 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
563 {
564 	unsigned long flags;
565 	unsigned int length, i;
566 
567 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
568 	if (ch == '\t') {
569 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
570 		raw->line_pos += length;
571 		ch = ' ';
572 	} else if (ch == '\n') {
573 		length = 1;
574 		raw->line_pos = 0;
575 	} else {
576 		length = 1;
577 		raw->line_pos++;
578 	}
579 	raw3215_make_room(raw, length);
580 
581 	for (i = 0; i < length; i++) {
582 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
583 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
584 		raw->count++;
585 	}
586 	if (!(raw->flags & RAW3215_WORKING)) {
587 		raw3215_mk_write_req(raw);
588 		/* start or queue request */
589 		raw3215_try_io(raw);
590 	}
591 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
592 }
593 
594 /*
595  * Flush routine, it simply sets the flush flag and tries to start
596  * pending IO.
597  */
598 static void raw3215_flush_buffer(struct raw3215_info *raw)
599 {
600 	unsigned long flags;
601 
602 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
603 	if (raw->count > 0) {
604 		raw->flags |= RAW3215_FLUSHING;
605 		raw3215_try_io(raw);
606 		raw->flags &= ~RAW3215_FLUSHING;
607 	}
608 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
609 }
610 
611 /*
612  * Fire up a 3215 device.
613  */
614 static int raw3215_startup(struct raw3215_info *raw)
615 {
616 	unsigned long flags;
617 
618 	if (tty_port_initialized(&raw->port))
619 		return 0;
620 	raw->line_pos = 0;
621 	tty_port_set_initialized(&raw->port, 1);
622 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
623 	raw3215_try_io(raw);
624 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
625 
626 	return 0;
627 }
628 
629 /*
630  * Shutdown a 3215 device.
631  */
632 static void raw3215_shutdown(struct raw3215_info *raw)
633 {
634 	DECLARE_WAITQUEUE(wait, current);
635 	unsigned long flags;
636 
637 	if (!tty_port_initialized(&raw->port) || (raw->flags & RAW3215_FIXED))
638 		return;
639 	/* Wait for outstanding requests, then free irq */
640 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
641 	if ((raw->flags & RAW3215_WORKING) ||
642 	    raw->queued_write != NULL ||
643 	    raw->queued_read != NULL) {
644 		add_wait_queue(&raw->empty_wait, &wait);
645 		set_current_state(TASK_INTERRUPTIBLE);
646 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
647 		schedule();
648 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
649 		remove_wait_queue(&raw->empty_wait, &wait);
650 		set_current_state(TASK_RUNNING);
651 		tty_port_set_initialized(&raw->port, 1);
652 	}
653 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
654 }
655 
656 static struct raw3215_info *raw3215_alloc_info(void)
657 {
658 	struct raw3215_info *info;
659 
660 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
661 	if (!info)
662 		return NULL;
663 
664 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
665 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
666 	if (!info->buffer || !info->inbuf) {
667 		kfree(info->inbuf);
668 		kfree(info->buffer);
669 		kfree(info);
670 		return NULL;
671 	}
672 
673 	timer_setup(&info->timer, raw3215_timeout, 0);
674 	init_waitqueue_head(&info->empty_wait);
675 	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
676 	tty_port_init(&info->port);
677 
678 	return info;
679 }
680 
681 static void raw3215_free_info(struct raw3215_info *raw)
682 {
683 	kfree(raw->inbuf);
684 	kfree(raw->buffer);
685 	tty_port_destroy(&raw->port);
686 	kfree(raw);
687 }
688 
689 static int raw3215_probe (struct ccw_device *cdev)
690 {
691 	struct raw3215_info *raw;
692 	int line;
693 
694 	/* Console is special. */
695 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
696 		return 0;
697 
698 	raw = raw3215_alloc_info();
699 	if (raw == NULL)
700 		return -ENOMEM;
701 
702 	raw->cdev = cdev;
703 	dev_set_drvdata(&cdev->dev, raw);
704 	cdev->handler = raw3215_irq;
705 
706 	spin_lock(&raw3215_device_lock);
707 	for (line = 0; line < NR_3215; line++) {
708 		if (!raw3215[line]) {
709 			raw3215[line] = raw;
710 			break;
711 		}
712 	}
713 	spin_unlock(&raw3215_device_lock);
714 	if (line == NR_3215) {
715 		raw3215_free_info(raw);
716 		return -ENODEV;
717 	}
718 
719 	return 0;
720 }
721 
722 static void raw3215_remove (struct ccw_device *cdev)
723 {
724 	struct raw3215_info *raw;
725 	unsigned int line;
726 
727 	ccw_device_set_offline(cdev);
728 	raw = dev_get_drvdata(&cdev->dev);
729 	if (raw) {
730 		spin_lock(&raw3215_device_lock);
731 		for (line = 0; line < NR_3215; line++)
732 			if (raw3215[line] == raw)
733 				break;
734 		raw3215[line] = NULL;
735 		spin_unlock(&raw3215_device_lock);
736 		dev_set_drvdata(&cdev->dev, NULL);
737 		raw3215_free_info(raw);
738 	}
739 }
740 
741 static int raw3215_set_online (struct ccw_device *cdev)
742 {
743 	struct raw3215_info *raw;
744 
745 	raw = dev_get_drvdata(&cdev->dev);
746 	if (!raw)
747 		return -ENODEV;
748 
749 	return raw3215_startup(raw);
750 }
751 
752 static int raw3215_set_offline (struct ccw_device *cdev)
753 {
754 	struct raw3215_info *raw;
755 
756 	raw = dev_get_drvdata(&cdev->dev);
757 	if (!raw)
758 		return -ENODEV;
759 
760 	raw3215_shutdown(raw);
761 
762 	return 0;
763 }
764 
765 static int raw3215_pm_stop(struct ccw_device *cdev)
766 {
767 	struct raw3215_info *raw;
768 	unsigned long flags;
769 
770 	/* Empty the output buffer, then prevent new I/O. */
771 	raw = dev_get_drvdata(&cdev->dev);
772 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
773 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
774 	tty_port_set_suspended(&raw->port, 1);
775 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
776 	return 0;
777 }
778 
779 static int raw3215_pm_start(struct ccw_device *cdev)
780 {
781 	struct raw3215_info *raw;
782 	unsigned long flags;
783 
784 	/* Allow I/O again and flush output buffer. */
785 	raw = dev_get_drvdata(&cdev->dev);
786 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
787 	tty_port_set_suspended(&raw->port, 0);
788 	raw->flags |= RAW3215_FLUSHING;
789 	raw3215_try_io(raw);
790 	raw->flags &= ~RAW3215_FLUSHING;
791 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
792 	return 0;
793 }
794 
795 static struct ccw_device_id raw3215_id[] = {
796 	{ CCW_DEVICE(0x3215, 0) },
797 	{ /* end of list */ },
798 };
799 
800 static struct ccw_driver raw3215_ccw_driver = {
801 	.driver = {
802 		.name	= "3215",
803 		.owner	= THIS_MODULE,
804 	},
805 	.ids		= raw3215_id,
806 	.probe		= &raw3215_probe,
807 	.remove		= &raw3215_remove,
808 	.set_online	= &raw3215_set_online,
809 	.set_offline	= &raw3215_set_offline,
810 	.freeze		= &raw3215_pm_stop,
811 	.thaw		= &raw3215_pm_start,
812 	.restore	= &raw3215_pm_start,
813 	.int_class	= IRQIO_C15,
814 };
815 
816 #ifdef CONFIG_TN3215_CONSOLE
817 /*
818  * Write a string to the 3215 console
819  */
820 static void con3215_write(struct console *co, const char *str,
821 			  unsigned int count)
822 {
823 	struct raw3215_info *raw;
824 	int i;
825 
826 	if (count <= 0)
827 		return;
828 	raw = raw3215[0];	/* console 3215 is the first one */
829 	while (count > 0) {
830 		for (i = 0; i < count; i++)
831 			if (str[i] == '\t' || str[i] == '\n')
832 				break;
833 		raw3215_write(raw, str, i);
834 		count -= i;
835 		str += i;
836 		if (count > 0) {
837 			raw3215_putchar(raw, *str);
838 			count--;
839 			str++;
840 		}
841 	}
842 }
843 
844 static struct tty_driver *con3215_device(struct console *c, int *index)
845 {
846 	*index = c->index;
847 	return tty3215_driver;
848 }
849 
850 /*
851  * panic() calls con3215_flush through a panic_notifier
852  * before the system enters a disabled, endless loop.
853  */
854 static void con3215_flush(void)
855 {
856 	struct raw3215_info *raw;
857 	unsigned long flags;
858 
859 	raw = raw3215[0];  /* console 3215 is the first one */
860 	if (tty_port_suspended(&raw->port))
861 		/* The console is still frozen for suspend. */
862 		if (ccw_device_force_console(raw->cdev))
863 			/* Forcing didn't work, no panic message .. */
864 			return;
865 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
866 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
867 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
868 }
869 
870 static int con3215_notify(struct notifier_block *self,
871 			  unsigned long event, void *data)
872 {
873 	con3215_flush();
874 	return NOTIFY_OK;
875 }
876 
877 static struct notifier_block on_panic_nb = {
878 	.notifier_call = con3215_notify,
879 	.priority = 0,
880 };
881 
882 static struct notifier_block on_reboot_nb = {
883 	.notifier_call = con3215_notify,
884 	.priority = 0,
885 };
886 
887 /*
888  *  The console structure for the 3215 console
889  */
890 static struct console con3215 = {
891 	.name	 = "ttyS",
892 	.write	 = con3215_write,
893 	.device	 = con3215_device,
894 	.flags	 = CON_PRINTBUFFER,
895 };
896 
897 /*
898  * 3215 console initialization code called from console_init().
899  */
900 static int __init con3215_init(void)
901 {
902 	struct ccw_device *cdev;
903 	struct raw3215_info *raw;
904 	struct raw3215_req *req;
905 	int i;
906 
907 	/* Check if 3215 is to be the console */
908 	if (!CONSOLE_IS_3215)
909 		return -ENODEV;
910 
911 	/* Set the console mode for VM */
912 	if (MACHINE_IS_VM) {
913 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
914 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
915 	}
916 
917 	/* allocate 3215 request structures */
918 	raw3215_freelist = NULL;
919 	spin_lock_init(&raw3215_freelist_lock);
920 	for (i = 0; i < NR_3215_REQ; i++) {
921 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
922 		if (!req)
923 			return -ENOMEM;
924 		req->next = raw3215_freelist;
925 		raw3215_freelist = req;
926 	}
927 
928 	cdev = ccw_device_create_console(&raw3215_ccw_driver);
929 	if (IS_ERR(cdev))
930 		return -ENODEV;
931 
932 	raw3215[0] = raw = raw3215_alloc_info();
933 	raw->cdev = cdev;
934 	dev_set_drvdata(&cdev->dev, raw);
935 	cdev->handler = raw3215_irq;
936 
937 	raw->flags |= RAW3215_FIXED;
938 	if (ccw_device_enable_console(cdev)) {
939 		ccw_device_destroy_console(cdev);
940 		raw3215_free_info(raw);
941 		raw3215[0] = NULL;
942 		return -ENODEV;
943 	}
944 
945 	/* Request the console irq */
946 	if (raw3215_startup(raw) != 0) {
947 		raw3215_free_info(raw);
948 		raw3215[0] = NULL;
949 		return -ENODEV;
950 	}
951 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
952 	register_reboot_notifier(&on_reboot_nb);
953 	register_console(&con3215);
954 	return 0;
955 }
956 console_initcall(con3215_init);
957 #endif
958 
959 static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
960 {
961 	struct raw3215_info *raw;
962 
963 	raw = raw3215[tty->index];
964 	if (raw == NULL)
965 		return -ENODEV;
966 
967 	tty->driver_data = raw;
968 
969 	return tty_port_install(&raw->port, driver, tty);
970 }
971 
972 /*
973  * tty3215_open
974  *
975  * This routine is called whenever a 3215 tty is opened.
976  */
977 static int tty3215_open(struct tty_struct *tty, struct file * filp)
978 {
979 	struct raw3215_info *raw = tty->driver_data;
980 	int retval;
981 
982 	tty_port_tty_set(&raw->port, tty);
983 
984 	raw->port.low_latency = 0; /* don't use bottom half for pushing chars */
985 	/*
986 	 * Start up 3215 device
987 	 */
988 	retval = raw3215_startup(raw);
989 	if (retval)
990 		return retval;
991 
992 	return 0;
993 }
994 
995 /*
996  * tty3215_close()
997  *
998  * This routine is called when the 3215 tty is closed. We wait
999  * for the remaining request to be completed. Then we clean up.
1000  */
1001 static void tty3215_close(struct tty_struct *tty, struct file * filp)
1002 {
1003 	struct raw3215_info *raw;
1004 
1005 	raw = (struct raw3215_info *) tty->driver_data;
1006 	if (raw == NULL || tty->count > 1)
1007 		return;
1008 	tty->closing = 1;
1009 	/* Shutdown the terminal */
1010 	raw3215_shutdown(raw);
1011 	tasklet_kill(&raw->tlet);
1012 	tty->closing = 0;
1013 	tty_port_tty_set(&raw->port, NULL);
1014 }
1015 
1016 /*
1017  * Returns the amount of free space in the output buffer.
1018  */
1019 static int tty3215_write_room(struct tty_struct *tty)
1020 {
1021 	struct raw3215_info *raw;
1022 
1023 	raw = (struct raw3215_info *) tty->driver_data;
1024 
1025 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1026 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1027 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1028 	else
1029 		return 0;
1030 }
1031 
1032 /*
1033  * String write routine for 3215 ttys
1034  */
1035 static int tty3215_write(struct tty_struct * tty,
1036 			 const unsigned char *buf, int count)
1037 {
1038 	struct raw3215_info *raw;
1039 	int i, written;
1040 
1041 	if (!tty)
1042 		return 0;
1043 	raw = (struct raw3215_info *) tty->driver_data;
1044 	written = count;
1045 	while (count > 0) {
1046 		for (i = 0; i < count; i++)
1047 			if (buf[i] == '\t' || buf[i] == '\n')
1048 				break;
1049 		raw3215_write(raw, buf, i);
1050 		count -= i;
1051 		buf += i;
1052 		if (count > 0) {
1053 			raw3215_putchar(raw, *buf);
1054 			count--;
1055 			buf++;
1056 		}
1057 	}
1058 	return written;
1059 }
1060 
1061 /*
1062  * Put character routine for 3215 ttys
1063  */
1064 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1065 {
1066 	struct raw3215_info *raw;
1067 
1068 	if (!tty)
1069 		return 0;
1070 	raw = (struct raw3215_info *) tty->driver_data;
1071 	raw3215_putchar(raw, ch);
1072 	return 1;
1073 }
1074 
1075 static void tty3215_flush_chars(struct tty_struct *tty)
1076 {
1077 }
1078 
1079 /*
1080  * Returns the number of characters in the output buffer
1081  */
1082 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1083 {
1084 	struct raw3215_info *raw;
1085 
1086 	raw = (struct raw3215_info *) tty->driver_data;
1087 	return raw->count;
1088 }
1089 
1090 static void tty3215_flush_buffer(struct tty_struct *tty)
1091 {
1092 	struct raw3215_info *raw;
1093 
1094 	raw = (struct raw3215_info *) tty->driver_data;
1095 	raw3215_flush_buffer(raw);
1096 	tty_wakeup(tty);
1097 }
1098 
1099 /*
1100  * Disable reading from a 3215 tty
1101  */
1102 static void tty3215_throttle(struct tty_struct * tty)
1103 {
1104 	struct raw3215_info *raw;
1105 
1106 	raw = (struct raw3215_info *) tty->driver_data;
1107 	raw->flags |= RAW3215_THROTTLED;
1108 }
1109 
1110 /*
1111  * Enable reading from a 3215 tty
1112  */
1113 static void tty3215_unthrottle(struct tty_struct * tty)
1114 {
1115 	struct raw3215_info *raw;
1116 	unsigned long flags;
1117 
1118 	raw = (struct raw3215_info *) tty->driver_data;
1119 	if (raw->flags & RAW3215_THROTTLED) {
1120 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1121 		raw->flags &= ~RAW3215_THROTTLED;
1122 		raw3215_try_io(raw);
1123 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1124 	}
1125 }
1126 
1127 /*
1128  * Disable writing to a 3215 tty
1129  */
1130 static void tty3215_stop(struct tty_struct *tty)
1131 {
1132 	struct raw3215_info *raw;
1133 
1134 	raw = (struct raw3215_info *) tty->driver_data;
1135 	raw->flags |= RAW3215_STOPPED;
1136 }
1137 
1138 /*
1139  * Enable writing to a 3215 tty
1140  */
1141 static void tty3215_start(struct tty_struct *tty)
1142 {
1143 	struct raw3215_info *raw;
1144 	unsigned long flags;
1145 
1146 	raw = (struct raw3215_info *) tty->driver_data;
1147 	if (raw->flags & RAW3215_STOPPED) {
1148 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1149 		raw->flags &= ~RAW3215_STOPPED;
1150 		raw3215_try_io(raw);
1151 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1152 	}
1153 }
1154 
1155 static const struct tty_operations tty3215_ops = {
1156 	.install = tty3215_install,
1157 	.open = tty3215_open,
1158 	.close = tty3215_close,
1159 	.write = tty3215_write,
1160 	.put_char = tty3215_put_char,
1161 	.flush_chars = tty3215_flush_chars,
1162 	.write_room = tty3215_write_room,
1163 	.chars_in_buffer = tty3215_chars_in_buffer,
1164 	.flush_buffer = tty3215_flush_buffer,
1165 	.throttle = tty3215_throttle,
1166 	.unthrottle = tty3215_unthrottle,
1167 	.stop = tty3215_stop,
1168 	.start = tty3215_start,
1169 };
1170 
1171 /*
1172  * 3215 tty registration code called from tty_init().
1173  * Most kernel services (incl. kmalloc) are available at this poimt.
1174  */
1175 static int __init tty3215_init(void)
1176 {
1177 	struct tty_driver *driver;
1178 	int ret;
1179 
1180 	if (!CONSOLE_IS_3215)
1181 		return 0;
1182 
1183 	driver = alloc_tty_driver(NR_3215);
1184 	if (!driver)
1185 		return -ENOMEM;
1186 
1187 	ret = ccw_driver_register(&raw3215_ccw_driver);
1188 	if (ret) {
1189 		put_tty_driver(driver);
1190 		return ret;
1191 	}
1192 	/*
1193 	 * Initialize the tty_driver structure
1194 	 * Entries in tty3215_driver that are NOT initialized:
1195 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1196 	 */
1197 
1198 	driver->driver_name = "tty3215";
1199 	driver->name = "ttyS";
1200 	driver->major = TTY_MAJOR;
1201 	driver->minor_start = 64;
1202 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1203 	driver->subtype = SYSTEM_TYPE_TTY;
1204 	driver->init_termios = tty_std_termios;
1205 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1206 	driver->init_termios.c_oflag = ONLCR;
1207 	driver->init_termios.c_lflag = ISIG;
1208 	driver->flags = TTY_DRIVER_REAL_RAW;
1209 	tty_set_operations(driver, &tty3215_ops);
1210 	ret = tty_register_driver(driver);
1211 	if (ret) {
1212 		put_tty_driver(driver);
1213 		return ret;
1214 	}
1215 	tty3215_driver = driver;
1216 	return 0;
1217 }
1218 device_initcall(tty3215_init);
1219