xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 8730046c)
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/types.h>
13 #include <linux/kdev_t.h>
14 #include <linux/tty.h>
15 #include <linux/tty_flip.h>
16 #include <linux/vt_kern.h>
17 #include <linux/init.h>
18 #include <linux/console.h>
19 #include <linux/interrupt.h>
20 #include <linux/err.h>
21 #include <linux/reboot.h>
22 #include <linux/serial.h> /* ASYNC_* flags */
23 #include <linux/slab.h>
24 #include <asm/ccwdev.h>
25 #include <asm/cio.h>
26 #include <asm/io.h>
27 #include <asm/ebcdic.h>
28 #include <linux/uaccess.h>
29 #include <asm/delay.h>
30 #include <asm/cpcmd.h>
31 #include <asm/setup.h>
32 
33 #include "ctrlchar.h"
34 
35 #define NR_3215		    1
36 #define NR_3215_REQ	    (4*NR_3215)
37 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
38 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
39 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
40 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
41 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
42 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
43 #define RAW3215_NR_CCWS	    3
44 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
45 
46 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
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 	raw->flags &= ~RAW3215_TIMER_RUNS;
291 	if (!tty_port_suspended(&raw->port)) {
292 		raw3215_mk_write_req(raw);
293 		raw3215_start_io(raw);
294 		if ((raw->queued_read || raw->queued_write) &&
295 		    !(raw->flags & RAW3215_WORKING) &&
296 		    !(raw->flags & RAW3215_TIMER_RUNS)) {
297 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
298 			add_timer(&raw->timer);
299 			raw->flags |= RAW3215_TIMER_RUNS;
300 		}
301 	}
302 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
303 }
304 
305 /*
306  * Function to conditionally start an IO. A read is started immediately,
307  * a write is only started immediately if the flush flag is on or the
308  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
309  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
310  */
311 static inline void raw3215_try_io(struct raw3215_info *raw)
312 {
313 	if (!tty_port_initialized(&raw->port) || tty_port_suspended(&raw->port))
314 		return;
315 	if (raw->queued_read != NULL)
316 		raw3215_start_io(raw);
317 	else if (raw->queued_write != NULL) {
318 		if ((raw->queued_write->delayable == 0) ||
319 		    (raw->flags & RAW3215_FLUSHING)) {
320 			/* execute write requests bigger than minimum size */
321 			raw3215_start_io(raw);
322 		}
323 	}
324 	if ((raw->queued_read || raw->queued_write) &&
325 	    !(raw->flags & RAW3215_WORKING) &&
326 	    !(raw->flags & RAW3215_TIMER_RUNS)) {
327 		raw->timer.expires = RAW3215_TIMEOUT + jiffies;
328 		add_timer(&raw->timer);
329 		raw->flags |= RAW3215_TIMER_RUNS;
330 	}
331 }
332 
333 /*
334  * Call tty_wakeup from tasklet context
335  */
336 static void raw3215_wakeup(unsigned long data)
337 {
338 	struct raw3215_info *raw = (struct raw3215_info *) data;
339 	struct tty_struct *tty;
340 
341 	tty = tty_port_tty_get(&raw->port);
342 	if (tty) {
343 		tty_wakeup(tty);
344 		tty_kref_put(tty);
345 	}
346 }
347 
348 /*
349  * Try to start the next IO and wake up processes waiting on the tty.
350  */
351 static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
352 {
353 	raw3215_mk_write_req(raw);
354 	raw3215_try_io(raw);
355 	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
356 		tasklet_schedule(&raw->tlet);
357 }
358 
359 /*
360  * Interrupt routine, called from common io layer
361  */
362 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
363 			struct irb *irb)
364 {
365 	struct raw3215_info *raw;
366 	struct raw3215_req *req;
367 	struct tty_struct *tty;
368 	int cstat, dstat;
369 	int count;
370 
371 	raw = dev_get_drvdata(&cdev->dev);
372 	req = (struct raw3215_req *) intparm;
373 	tty = tty_port_tty_get(&raw->port);
374 	cstat = irb->scsw.cmd.cstat;
375 	dstat = irb->scsw.cmd.dstat;
376 	if (cstat != 0)
377 		raw3215_next_io(raw, tty);
378 	if (dstat & 0x01) { /* we got a unit exception */
379 		dstat &= ~0x01;	 /* we can ignore it */
380 	}
381 	switch (dstat) {
382 	case 0x80:
383 		if (cstat != 0)
384 			break;
385 		/* Attention interrupt, someone hit the enter key */
386 		raw3215_mk_read_req(raw);
387 		raw3215_next_io(raw, tty);
388 		break;
389 	case 0x08:
390 	case 0x0C:
391 		/* Channel end interrupt. */
392 		if ((raw = req->info) == NULL)
393 			goto put_tty;	     /* That shouldn't happen ... */
394 		if (req->type == RAW3215_READ) {
395 			/* store residual count, then wait for device end */
396 			req->residual = irb->scsw.cmd.count;
397 		}
398 		if (dstat == 0x08)
399 			break;
400 	case 0x04:
401 		/* Device end interrupt. */
402 		if ((raw = req->info) == NULL)
403 			goto put_tty;	     /* That shouldn't happen ... */
404 		if (req->type == RAW3215_READ && tty != NULL) {
405 			unsigned int cchar;
406 
407 			count = 160 - req->residual;
408 			EBCASC(raw->inbuf, count);
409 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
410 			switch (cchar & CTRLCHAR_MASK) {
411 			case CTRLCHAR_SYSRQ:
412 				break;
413 
414 			case CTRLCHAR_CTRL:
415 				tty_insert_flip_char(&raw->port, cchar,
416 						TTY_NORMAL);
417 				tty_flip_buffer_push(&raw->port);
418 				break;
419 
420 			case CTRLCHAR_NONE:
421 				if (count < 2 ||
422 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
423 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
424 					/* add the auto \n */
425 					raw->inbuf[count] = '\n';
426 					count++;
427 				} else
428 					count -= 2;
429 				tty_insert_flip_string(&raw->port, raw->inbuf,
430 						count);
431 				tty_flip_buffer_push(&raw->port);
432 				break;
433 			}
434 		} else if (req->type == RAW3215_WRITE) {
435 			raw->count -= req->len;
436 			raw->written -= req->len;
437 		}
438 		raw->flags &= ~RAW3215_WORKING;
439 		raw3215_free_req(req);
440 		/* check for empty wait */
441 		if (waitqueue_active(&raw->empty_wait) &&
442 		    raw->queued_write == NULL &&
443 		    raw->queued_read == NULL) {
444 			wake_up_interruptible(&raw->empty_wait);
445 		}
446 		raw3215_next_io(raw, tty);
447 		break;
448 	default:
449 		/* Strange interrupt, I'll do my best to clean up */
450 		if (req != NULL && req->type != RAW3215_FREE) {
451 			if (req->type == RAW3215_WRITE) {
452 				raw->count -= req->len;
453 				raw->written -= req->len;
454 			}
455 			raw->flags &= ~RAW3215_WORKING;
456 			raw3215_free_req(req);
457 		}
458 		raw3215_next_io(raw, tty);
459 	}
460 put_tty:
461 	tty_kref_put(tty);
462 }
463 
464 /*
465  * Drop the oldest line from the output buffer.
466  */
467 static void raw3215_drop_line(struct raw3215_info *raw)
468 {
469 	int ix;
470 	char ch;
471 
472 	BUG_ON(raw->written != 0);
473 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
474 	while (raw->count > 0) {
475 		ch = raw->buffer[ix];
476 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
477 		raw->count--;
478 		if (ch == 0x15)
479 			break;
480 	}
481 	raw->head = ix;
482 }
483 
484 /*
485  * Wait until length bytes are available int the output buffer.
486  * Has to be called with the s390irq lock held. Can be called
487  * disabled.
488  */
489 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
490 {
491 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
492 		/* While console is frozen for suspend we have no other
493 		 * choice but to drop message from the buffer to make
494 		 * room for even more messages. */
495 		if (tty_port_suspended(&raw->port)) {
496 			raw3215_drop_line(raw);
497 			continue;
498 		}
499 		/* there might be a request pending */
500 		raw->flags |= RAW3215_FLUSHING;
501 		raw3215_mk_write_req(raw);
502 		raw3215_try_io(raw);
503 		raw->flags &= ~RAW3215_FLUSHING;
504 #ifdef CONFIG_TN3215_CONSOLE
505 		ccw_device_wait_idle(raw->cdev);
506 #endif
507 		/* Enough room freed up ? */
508 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
509 			break;
510 		/* there might be another cpu waiting for the lock */
511 		spin_unlock(get_ccwdev_lock(raw->cdev));
512 		udelay(100);
513 		spin_lock(get_ccwdev_lock(raw->cdev));
514 	}
515 }
516 
517 /*
518  * String write routine for 3215 devices
519  */
520 static void raw3215_write(struct raw3215_info *raw, const char *str,
521 			  unsigned int length)
522 {
523 	unsigned long flags;
524 	int c, count;
525 
526 	while (length > 0) {
527 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
528 		count = (length > RAW3215_BUFFER_SIZE) ?
529 					     RAW3215_BUFFER_SIZE : length;
530 		length -= count;
531 
532 		raw3215_make_room(raw, count);
533 
534 		/* copy string to output buffer and convert it to EBCDIC */
535 		while (1) {
536 			c = min_t(int, count,
537 				  min(RAW3215_BUFFER_SIZE - raw->count,
538 				      RAW3215_BUFFER_SIZE - raw->head));
539 			if (c <= 0)
540 				break;
541 			memcpy(raw->buffer + raw->head, str, c);
542 			ASCEBC(raw->buffer + raw->head, c);
543 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
544 			raw->count += c;
545 			raw->line_pos += c;
546 			str += c;
547 			count -= c;
548 		}
549 		if (!(raw->flags & RAW3215_WORKING)) {
550 			raw3215_mk_write_req(raw);
551 			/* start or queue request */
552 			raw3215_try_io(raw);
553 		}
554 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
555 	}
556 }
557 
558 /*
559  * Put character routine for 3215 devices
560  */
561 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
562 {
563 	unsigned long flags;
564 	unsigned int length, i;
565 
566 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
567 	if (ch == '\t') {
568 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
569 		raw->line_pos += length;
570 		ch = ' ';
571 	} else if (ch == '\n') {
572 		length = 1;
573 		raw->line_pos = 0;
574 	} else {
575 		length = 1;
576 		raw->line_pos++;
577 	}
578 	raw3215_make_room(raw, length);
579 
580 	for (i = 0; i < length; i++) {
581 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
582 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
583 		raw->count++;
584 	}
585 	if (!(raw->flags & RAW3215_WORKING)) {
586 		raw3215_mk_write_req(raw);
587 		/* start or queue request */
588 		raw3215_try_io(raw);
589 	}
590 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
591 }
592 
593 /*
594  * Flush routine, it simply sets the flush flag and tries to start
595  * pending IO.
596  */
597 static void raw3215_flush_buffer(struct raw3215_info *raw)
598 {
599 	unsigned long flags;
600 
601 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
602 	if (raw->count > 0) {
603 		raw->flags |= RAW3215_FLUSHING;
604 		raw3215_try_io(raw);
605 		raw->flags &= ~RAW3215_FLUSHING;
606 	}
607 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
608 }
609 
610 /*
611  * Fire up a 3215 device.
612  */
613 static int raw3215_startup(struct raw3215_info *raw)
614 {
615 	unsigned long flags;
616 
617 	if (tty_port_initialized(&raw->port))
618 		return 0;
619 	raw->line_pos = 0;
620 	tty_port_set_initialized(&raw->port, 1);
621 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
622 	raw3215_try_io(raw);
623 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
624 
625 	return 0;
626 }
627 
628 /*
629  * Shutdown a 3215 device.
630  */
631 static void raw3215_shutdown(struct raw3215_info *raw)
632 {
633 	DECLARE_WAITQUEUE(wait, current);
634 	unsigned long flags;
635 
636 	if (!tty_port_initialized(&raw->port) || (raw->flags & RAW3215_FIXED))
637 		return;
638 	/* Wait for outstanding requests, then free irq */
639 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
640 	if ((raw->flags & RAW3215_WORKING) ||
641 	    raw->queued_write != NULL ||
642 	    raw->queued_read != NULL) {
643 		add_wait_queue(&raw->empty_wait, &wait);
644 		set_current_state(TASK_INTERRUPTIBLE);
645 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
646 		schedule();
647 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
648 		remove_wait_queue(&raw->empty_wait, &wait);
649 		set_current_state(TASK_RUNNING);
650 		tty_port_set_initialized(&raw->port, 1);
651 	}
652 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
653 }
654 
655 static struct raw3215_info *raw3215_alloc_info(void)
656 {
657 	struct raw3215_info *info;
658 
659 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
660 	if (!info)
661 		return NULL;
662 
663 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
664 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
665 	if (!info->buffer || !info->inbuf) {
666 		kfree(info->inbuf);
667 		kfree(info->buffer);
668 		kfree(info);
669 		return NULL;
670 	}
671 
672 	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
673 	init_waitqueue_head(&info->empty_wait);
674 	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
675 	tty_port_init(&info->port);
676 
677 	return info;
678 }
679 
680 static void raw3215_free_info(struct raw3215_info *raw)
681 {
682 	kfree(raw->inbuf);
683 	kfree(raw->buffer);
684 	tty_port_destroy(&raw->port);
685 	kfree(raw);
686 }
687 
688 static int raw3215_probe (struct ccw_device *cdev)
689 {
690 	struct raw3215_info *raw;
691 	int line;
692 
693 	/* Console is special. */
694 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
695 		return 0;
696 
697 	raw = raw3215_alloc_info();
698 	if (raw == NULL)
699 		return -ENOMEM;
700 
701 	raw->cdev = cdev;
702 	dev_set_drvdata(&cdev->dev, raw);
703 	cdev->handler = raw3215_irq;
704 
705 	spin_lock(&raw3215_device_lock);
706 	for (line = 0; line < NR_3215; line++) {
707 		if (!raw3215[line]) {
708 			raw3215[line] = raw;
709 			break;
710 		}
711 	}
712 	spin_unlock(&raw3215_device_lock);
713 	if (line == NR_3215) {
714 		raw3215_free_info(raw);
715 		return -ENODEV;
716 	}
717 
718 	return 0;
719 }
720 
721 static void raw3215_remove (struct ccw_device *cdev)
722 {
723 	struct raw3215_info *raw;
724 	unsigned int line;
725 
726 	ccw_device_set_offline(cdev);
727 	raw = dev_get_drvdata(&cdev->dev);
728 	if (raw) {
729 		spin_lock(&raw3215_device_lock);
730 		for (line = 0; line < NR_3215; line++)
731 			if (raw3215[line] == raw)
732 				break;
733 		raw3215[line] = NULL;
734 		spin_unlock(&raw3215_device_lock);
735 		dev_set_drvdata(&cdev->dev, NULL);
736 		raw3215_free_info(raw);
737 	}
738 }
739 
740 static int raw3215_set_online (struct ccw_device *cdev)
741 {
742 	struct raw3215_info *raw;
743 
744 	raw = dev_get_drvdata(&cdev->dev);
745 	if (!raw)
746 		return -ENODEV;
747 
748 	return raw3215_startup(raw);
749 }
750 
751 static int raw3215_set_offline (struct ccw_device *cdev)
752 {
753 	struct raw3215_info *raw;
754 
755 	raw = dev_get_drvdata(&cdev->dev);
756 	if (!raw)
757 		return -ENODEV;
758 
759 	raw3215_shutdown(raw);
760 
761 	return 0;
762 }
763 
764 static int raw3215_pm_stop(struct ccw_device *cdev)
765 {
766 	struct raw3215_info *raw;
767 	unsigned long flags;
768 
769 	/* Empty the output buffer, then prevent new I/O. */
770 	raw = dev_get_drvdata(&cdev->dev);
771 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
772 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
773 	tty_port_set_suspended(&raw->port, 1);
774 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
775 	return 0;
776 }
777 
778 static int raw3215_pm_start(struct ccw_device *cdev)
779 {
780 	struct raw3215_info *raw;
781 	unsigned long flags;
782 
783 	/* Allow I/O again and flush output buffer. */
784 	raw = dev_get_drvdata(&cdev->dev);
785 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
786 	tty_port_set_suspended(&raw->port, 0);
787 	raw->flags |= RAW3215_FLUSHING;
788 	raw3215_try_io(raw);
789 	raw->flags &= ~RAW3215_FLUSHING;
790 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
791 	return 0;
792 }
793 
794 static struct ccw_device_id raw3215_id[] = {
795 	{ CCW_DEVICE(0x3215, 0) },
796 	{ /* end of list */ },
797 };
798 
799 static struct ccw_driver raw3215_ccw_driver = {
800 	.driver = {
801 		.name	= "3215",
802 		.owner	= THIS_MODULE,
803 	},
804 	.ids		= raw3215_id,
805 	.probe		= &raw3215_probe,
806 	.remove		= &raw3215_remove,
807 	.set_online	= &raw3215_set_online,
808 	.set_offline	= &raw3215_set_offline,
809 	.freeze		= &raw3215_pm_stop,
810 	.thaw		= &raw3215_pm_start,
811 	.restore	= &raw3215_pm_start,
812 	.int_class	= IRQIO_C15,
813 };
814 
815 #ifdef CONFIG_TN3215_CONSOLE
816 /*
817  * Write a string to the 3215 console
818  */
819 static void con3215_write(struct console *co, const char *str,
820 			  unsigned int count)
821 {
822 	struct raw3215_info *raw;
823 	int i;
824 
825 	if (count <= 0)
826 		return;
827 	raw = raw3215[0];	/* console 3215 is the first one */
828 	while (count > 0) {
829 		for (i = 0; i < count; i++)
830 			if (str[i] == '\t' || str[i] == '\n')
831 				break;
832 		raw3215_write(raw, str, i);
833 		count -= i;
834 		str += i;
835 		if (count > 0) {
836 			raw3215_putchar(raw, *str);
837 			count--;
838 			str++;
839 		}
840 	}
841 }
842 
843 static struct tty_driver *con3215_device(struct console *c, int *index)
844 {
845 	*index = c->index;
846 	return tty3215_driver;
847 }
848 
849 /*
850  * panic() calls con3215_flush through a panic_notifier
851  * before the system enters a disabled, endless loop.
852  */
853 static void con3215_flush(void)
854 {
855 	struct raw3215_info *raw;
856 	unsigned long flags;
857 
858 	raw = raw3215[0];  /* console 3215 is the first one */
859 	if (tty_port_suspended(&raw->port))
860 		/* The console is still frozen for suspend. */
861 		if (ccw_device_force_console(raw->cdev))
862 			/* Forcing didn't work, no panic message .. */
863 			return;
864 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
865 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
866 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
867 }
868 
869 static int con3215_notify(struct notifier_block *self,
870 			  unsigned long event, void *data)
871 {
872 	con3215_flush();
873 	return NOTIFY_OK;
874 }
875 
876 static struct notifier_block on_panic_nb = {
877 	.notifier_call = con3215_notify,
878 	.priority = 0,
879 };
880 
881 static struct notifier_block on_reboot_nb = {
882 	.notifier_call = con3215_notify,
883 	.priority = 0,
884 };
885 
886 /*
887  *  The console structure for the 3215 console
888  */
889 static struct console con3215 = {
890 	.name	 = "ttyS",
891 	.write	 = con3215_write,
892 	.device	 = con3215_device,
893 	.flags	 = CON_PRINTBUFFER,
894 };
895 
896 /*
897  * 3215 console initialization code called from console_init().
898  */
899 static int __init con3215_init(void)
900 {
901 	struct ccw_device *cdev;
902 	struct raw3215_info *raw;
903 	struct raw3215_req *req;
904 	int i;
905 
906 	/* Check if 3215 is to be the console */
907 	if (!CONSOLE_IS_3215)
908 		return -ENODEV;
909 
910 	/* Set the console mode for VM */
911 	if (MACHINE_IS_VM) {
912 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
913 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
914 	}
915 
916 	/* allocate 3215 request structures */
917 	raw3215_freelist = NULL;
918 	spin_lock_init(&raw3215_freelist_lock);
919 	for (i = 0; i < NR_3215_REQ; i++) {
920 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
921 		if (!req)
922 			return -ENOMEM;
923 		req->next = raw3215_freelist;
924 		raw3215_freelist = req;
925 	}
926 
927 	cdev = ccw_device_create_console(&raw3215_ccw_driver);
928 	if (IS_ERR(cdev))
929 		return -ENODEV;
930 
931 	raw3215[0] = raw = raw3215_alloc_info();
932 	raw->cdev = cdev;
933 	dev_set_drvdata(&cdev->dev, raw);
934 	cdev->handler = raw3215_irq;
935 
936 	raw->flags |= RAW3215_FIXED;
937 	if (ccw_device_enable_console(cdev)) {
938 		ccw_device_destroy_console(cdev);
939 		raw3215_free_info(raw);
940 		raw3215[0] = NULL;
941 		return -ENODEV;
942 	}
943 
944 	/* Request the console irq */
945 	if (raw3215_startup(raw) != 0) {
946 		raw3215_free_info(raw);
947 		raw3215[0] = NULL;
948 		return -ENODEV;
949 	}
950 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
951 	register_reboot_notifier(&on_reboot_nb);
952 	register_console(&con3215);
953 	return 0;
954 }
955 console_initcall(con3215_init);
956 #endif
957 
958 static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
959 {
960 	struct raw3215_info *raw;
961 
962 	raw = raw3215[tty->index];
963 	if (raw == NULL)
964 		return -ENODEV;
965 
966 	tty->driver_data = raw;
967 
968 	return tty_port_install(&raw->port, driver, tty);
969 }
970 
971 /*
972  * tty3215_open
973  *
974  * This routine is called whenever a 3215 tty is opened.
975  */
976 static int tty3215_open(struct tty_struct *tty, struct file * filp)
977 {
978 	struct raw3215_info *raw = tty->driver_data;
979 	int retval;
980 
981 	tty_port_tty_set(&raw->port, tty);
982 
983 	raw->port.low_latency = 0; /* don't use bottom half for pushing chars */
984 	/*
985 	 * Start up 3215 device
986 	 */
987 	retval = raw3215_startup(raw);
988 	if (retval)
989 		return retval;
990 
991 	return 0;
992 }
993 
994 /*
995  * tty3215_close()
996  *
997  * This routine is called when the 3215 tty is closed. We wait
998  * for the remaining request to be completed. Then we clean up.
999  */
1000 static void tty3215_close(struct tty_struct *tty, struct file * filp)
1001 {
1002 	struct raw3215_info *raw;
1003 
1004 	raw = (struct raw3215_info *) tty->driver_data;
1005 	if (raw == NULL || tty->count > 1)
1006 		return;
1007 	tty->closing = 1;
1008 	/* Shutdown the terminal */
1009 	raw3215_shutdown(raw);
1010 	tasklet_kill(&raw->tlet);
1011 	tty->closing = 0;
1012 	tty_port_tty_set(&raw->port, NULL);
1013 }
1014 
1015 /*
1016  * Returns the amount of free space in the output buffer.
1017  */
1018 static int tty3215_write_room(struct tty_struct *tty)
1019 {
1020 	struct raw3215_info *raw;
1021 
1022 	raw = (struct raw3215_info *) tty->driver_data;
1023 
1024 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1025 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1026 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1027 	else
1028 		return 0;
1029 }
1030 
1031 /*
1032  * String write routine for 3215 ttys
1033  */
1034 static int tty3215_write(struct tty_struct * tty,
1035 			 const unsigned char *buf, int count)
1036 {
1037 	struct raw3215_info *raw;
1038 	int i, written;
1039 
1040 	if (!tty)
1041 		return 0;
1042 	raw = (struct raw3215_info *) tty->driver_data;
1043 	written = count;
1044 	while (count > 0) {
1045 		for (i = 0; i < count; i++)
1046 			if (buf[i] == '\t' || buf[i] == '\n')
1047 				break;
1048 		raw3215_write(raw, buf, i);
1049 		count -= i;
1050 		buf += i;
1051 		if (count > 0) {
1052 			raw3215_putchar(raw, *buf);
1053 			count--;
1054 			buf++;
1055 		}
1056 	}
1057 	return written;
1058 }
1059 
1060 /*
1061  * Put character routine for 3215 ttys
1062  */
1063 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1064 {
1065 	struct raw3215_info *raw;
1066 
1067 	if (!tty)
1068 		return 0;
1069 	raw = (struct raw3215_info *) tty->driver_data;
1070 	raw3215_putchar(raw, ch);
1071 	return 1;
1072 }
1073 
1074 static void tty3215_flush_chars(struct tty_struct *tty)
1075 {
1076 }
1077 
1078 /*
1079  * Returns the number of characters in the output buffer
1080  */
1081 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1082 {
1083 	struct raw3215_info *raw;
1084 
1085 	raw = (struct raw3215_info *) tty->driver_data;
1086 	return raw->count;
1087 }
1088 
1089 static void tty3215_flush_buffer(struct tty_struct *tty)
1090 {
1091 	struct raw3215_info *raw;
1092 
1093 	raw = (struct raw3215_info *) tty->driver_data;
1094 	raw3215_flush_buffer(raw);
1095 	tty_wakeup(tty);
1096 }
1097 
1098 /*
1099  * Disable reading from a 3215 tty
1100  */
1101 static void tty3215_throttle(struct tty_struct * tty)
1102 {
1103 	struct raw3215_info *raw;
1104 
1105 	raw = (struct raw3215_info *) tty->driver_data;
1106 	raw->flags |= RAW3215_THROTTLED;
1107 }
1108 
1109 /*
1110  * Enable reading from a 3215 tty
1111  */
1112 static void tty3215_unthrottle(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_THROTTLED) {
1119 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1120 		raw->flags &= ~RAW3215_THROTTLED;
1121 		raw3215_try_io(raw);
1122 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1123 	}
1124 }
1125 
1126 /*
1127  * Disable writing to a 3215 tty
1128  */
1129 static void tty3215_stop(struct tty_struct *tty)
1130 {
1131 	struct raw3215_info *raw;
1132 
1133 	raw = (struct raw3215_info *) tty->driver_data;
1134 	raw->flags |= RAW3215_STOPPED;
1135 }
1136 
1137 /*
1138  * Enable writing to a 3215 tty
1139  */
1140 static void tty3215_start(struct tty_struct *tty)
1141 {
1142 	struct raw3215_info *raw;
1143 	unsigned long flags;
1144 
1145 	raw = (struct raw3215_info *) tty->driver_data;
1146 	if (raw->flags & RAW3215_STOPPED) {
1147 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1148 		raw->flags &= ~RAW3215_STOPPED;
1149 		raw3215_try_io(raw);
1150 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1151 	}
1152 }
1153 
1154 static const struct tty_operations tty3215_ops = {
1155 	.install = tty3215_install,
1156 	.open = tty3215_open,
1157 	.close = tty3215_close,
1158 	.write = tty3215_write,
1159 	.put_char = tty3215_put_char,
1160 	.flush_chars = tty3215_flush_chars,
1161 	.write_room = tty3215_write_room,
1162 	.chars_in_buffer = tty3215_chars_in_buffer,
1163 	.flush_buffer = tty3215_flush_buffer,
1164 	.throttle = tty3215_throttle,
1165 	.unthrottle = tty3215_unthrottle,
1166 	.stop = tty3215_stop,
1167 	.start = tty3215_start,
1168 };
1169 
1170 /*
1171  * 3215 tty registration code called from tty_init().
1172  * Most kernel services (incl. kmalloc) are available at this poimt.
1173  */
1174 static int __init tty3215_init(void)
1175 {
1176 	struct tty_driver *driver;
1177 	int ret;
1178 
1179 	if (!CONSOLE_IS_3215)
1180 		return 0;
1181 
1182 	driver = alloc_tty_driver(NR_3215);
1183 	if (!driver)
1184 		return -ENOMEM;
1185 
1186 	ret = ccw_driver_register(&raw3215_ccw_driver);
1187 	if (ret) {
1188 		put_tty_driver(driver);
1189 		return ret;
1190 	}
1191 	/*
1192 	 * Initialize the tty_driver structure
1193 	 * Entries in tty3215_driver that are NOT initialized:
1194 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1195 	 */
1196 
1197 	driver->driver_name = "tty3215";
1198 	driver->name = "ttyS";
1199 	driver->major = TTY_MAJOR;
1200 	driver->minor_start = 64;
1201 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1202 	driver->subtype = SYSTEM_TYPE_TTY;
1203 	driver->init_termios = tty_std_termios;
1204 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1205 	driver->init_termios.c_oflag = ONLCR;
1206 	driver->init_termios.c_lflag = ISIG;
1207 	driver->flags = TTY_DRIVER_REAL_RAW;
1208 	tty_set_operations(driver, &tty3215_ops);
1209 	ret = tty_register_driver(driver);
1210 	if (ret) {
1211 		put_tty_driver(driver);
1212 		return ret;
1213 	}
1214 	tty3215_driver = driver;
1215 	return 0;
1216 }
1217 device_initcall(tty3215_init);
1218