xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 110e6f26)
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_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(unsigned long __data)
286 {
287 	struct raw3215_info *raw = (struct raw3215_info *) __data;
288 	unsigned long flags;
289 
290 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
291 	raw->flags &= ~RAW3215_TIMER_RUNS;
292 	if (!(raw->port.flags & ASYNC_SUSPENDED)) {
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 (!(raw->port.flags & ASYNC_INITIALIZED) ||
315 			(raw->port.flags & ASYNC_SUSPENDED))
316 		return;
317 	if (raw->queued_read != NULL)
318 		raw3215_start_io(raw);
319 	else if (raw->queued_write != NULL) {
320 		if ((raw->queued_write->delayable == 0) ||
321 		    (raw->flags & RAW3215_FLUSHING)) {
322 			/* execute write requests bigger than minimum size */
323 			raw3215_start_io(raw);
324 		}
325 	}
326 	if ((raw->queued_read || raw->queued_write) &&
327 	    !(raw->flags & RAW3215_WORKING) &&
328 	    !(raw->flags & RAW3215_TIMER_RUNS)) {
329 		raw->timer.expires = RAW3215_TIMEOUT + jiffies;
330 		add_timer(&raw->timer);
331 		raw->flags |= RAW3215_TIMER_RUNS;
332 	}
333 }
334 
335 /*
336  * Call tty_wakeup from tasklet context
337  */
338 static void raw3215_wakeup(unsigned long data)
339 {
340 	struct raw3215_info *raw = (struct raw3215_info *) data;
341 	struct tty_struct *tty;
342 
343 	tty = tty_port_tty_get(&raw->port);
344 	if (tty) {
345 		tty_wakeup(tty);
346 		tty_kref_put(tty);
347 	}
348 }
349 
350 /*
351  * Try to start the next IO and wake up processes waiting on the tty.
352  */
353 static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
354 {
355 	raw3215_mk_write_req(raw);
356 	raw3215_try_io(raw);
357 	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
358 		tasklet_schedule(&raw->tlet);
359 }
360 
361 /*
362  * Interrupt routine, called from common io layer
363  */
364 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
365 			struct irb *irb)
366 {
367 	struct raw3215_info *raw;
368 	struct raw3215_req *req;
369 	struct tty_struct *tty;
370 	int cstat, dstat;
371 	int count;
372 
373 	raw = dev_get_drvdata(&cdev->dev);
374 	req = (struct raw3215_req *) intparm;
375 	tty = tty_port_tty_get(&raw->port);
376 	cstat = irb->scsw.cmd.cstat;
377 	dstat = irb->scsw.cmd.dstat;
378 	if (cstat != 0)
379 		raw3215_next_io(raw, tty);
380 	if (dstat & 0x01) { /* we got a unit exception */
381 		dstat &= ~0x01;	 /* we can ignore it */
382 	}
383 	switch (dstat) {
384 	case 0x80:
385 		if (cstat != 0)
386 			break;
387 		/* Attention interrupt, someone hit the enter key */
388 		raw3215_mk_read_req(raw);
389 		raw3215_next_io(raw, tty);
390 		break;
391 	case 0x08:
392 	case 0x0C:
393 		/* Channel end interrupt. */
394 		if ((raw = req->info) == NULL)
395 			goto put_tty;	     /* That shouldn't happen ... */
396 		if (req->type == RAW3215_READ) {
397 			/* store residual count, then wait for device end */
398 			req->residual = irb->scsw.cmd.count;
399 		}
400 		if (dstat == 0x08)
401 			break;
402 	case 0x04:
403 		/* Device end interrupt. */
404 		if ((raw = req->info) == NULL)
405 			goto put_tty;	     /* That shouldn't happen ... */
406 		if (req->type == RAW3215_READ && tty != NULL) {
407 			unsigned int cchar;
408 
409 			count = 160 - req->residual;
410 			EBCASC(raw->inbuf, count);
411 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
412 			switch (cchar & CTRLCHAR_MASK) {
413 			case CTRLCHAR_SYSRQ:
414 				break;
415 
416 			case CTRLCHAR_CTRL:
417 				tty_insert_flip_char(&raw->port, cchar,
418 						TTY_NORMAL);
419 				tty_flip_buffer_push(&raw->port);
420 				break;
421 
422 			case CTRLCHAR_NONE:
423 				if (count < 2 ||
424 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
425 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
426 					/* add the auto \n */
427 					raw->inbuf[count] = '\n';
428 					count++;
429 				} else
430 					count -= 2;
431 				tty_insert_flip_string(&raw->port, raw->inbuf,
432 						count);
433 				tty_flip_buffer_push(&raw->port);
434 				break;
435 			}
436 		} else if (req->type == RAW3215_WRITE) {
437 			raw->count -= req->len;
438 			raw->written -= req->len;
439 		}
440 		raw->flags &= ~RAW3215_WORKING;
441 		raw3215_free_req(req);
442 		/* check for empty wait */
443 		if (waitqueue_active(&raw->empty_wait) &&
444 		    raw->queued_write == NULL &&
445 		    raw->queued_read == NULL) {
446 			wake_up_interruptible(&raw->empty_wait);
447 		}
448 		raw3215_next_io(raw, tty);
449 		break;
450 	default:
451 		/* Strange interrupt, I'll do my best to clean up */
452 		if (req != NULL && req->type != RAW3215_FREE) {
453 			if (req->type == RAW3215_WRITE) {
454 				raw->count -= req->len;
455 				raw->written -= req->len;
456 			}
457 			raw->flags &= ~RAW3215_WORKING;
458 			raw3215_free_req(req);
459 		}
460 		raw3215_next_io(raw, tty);
461 	}
462 put_tty:
463 	tty_kref_put(tty);
464 }
465 
466 /*
467  * Drop the oldest line from the output buffer.
468  */
469 static void raw3215_drop_line(struct raw3215_info *raw)
470 {
471 	int ix;
472 	char ch;
473 
474 	BUG_ON(raw->written != 0);
475 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
476 	while (raw->count > 0) {
477 		ch = raw->buffer[ix];
478 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
479 		raw->count--;
480 		if (ch == 0x15)
481 			break;
482 	}
483 	raw->head = ix;
484 }
485 
486 /*
487  * Wait until length bytes are available int the output buffer.
488  * Has to be called with the s390irq lock held. Can be called
489  * disabled.
490  */
491 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
492 {
493 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
494 		/* While console is frozen for suspend we have no other
495 		 * choice but to drop message from the buffer to make
496 		 * room for even more messages. */
497 		if (raw->port.flags & ASYNC_SUSPENDED) {
498 			raw3215_drop_line(raw);
499 			continue;
500 		}
501 		/* there might be a request pending */
502 		raw->flags |= RAW3215_FLUSHING;
503 		raw3215_mk_write_req(raw);
504 		raw3215_try_io(raw);
505 		raw->flags &= ~RAW3215_FLUSHING;
506 #ifdef CONFIG_TN3215_CONSOLE
507 		ccw_device_wait_idle(raw->cdev);
508 #endif
509 		/* Enough room freed up ? */
510 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
511 			break;
512 		/* there might be another cpu waiting for the lock */
513 		spin_unlock(get_ccwdev_lock(raw->cdev));
514 		udelay(100);
515 		spin_lock(get_ccwdev_lock(raw->cdev));
516 	}
517 }
518 
519 /*
520  * String write routine for 3215 devices
521  */
522 static void raw3215_write(struct raw3215_info *raw, const char *str,
523 			  unsigned int length)
524 {
525 	unsigned long flags;
526 	int c, count;
527 
528 	while (length > 0) {
529 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
530 		count = (length > RAW3215_BUFFER_SIZE) ?
531 					     RAW3215_BUFFER_SIZE : length;
532 		length -= count;
533 
534 		raw3215_make_room(raw, count);
535 
536 		/* copy string to output buffer and convert it to EBCDIC */
537 		while (1) {
538 			c = min_t(int, count,
539 				  min(RAW3215_BUFFER_SIZE - raw->count,
540 				      RAW3215_BUFFER_SIZE - raw->head));
541 			if (c <= 0)
542 				break;
543 			memcpy(raw->buffer + raw->head, str, c);
544 			ASCEBC(raw->buffer + raw->head, c);
545 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
546 			raw->count += c;
547 			raw->line_pos += c;
548 			str += c;
549 			count -= c;
550 		}
551 		if (!(raw->flags & RAW3215_WORKING)) {
552 			raw3215_mk_write_req(raw);
553 			/* start or queue request */
554 			raw3215_try_io(raw);
555 		}
556 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
557 	}
558 }
559 
560 /*
561  * Put character routine for 3215 devices
562  */
563 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
564 {
565 	unsigned long flags;
566 	unsigned int length, i;
567 
568 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
569 	if (ch == '\t') {
570 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
571 		raw->line_pos += length;
572 		ch = ' ';
573 	} else if (ch == '\n') {
574 		length = 1;
575 		raw->line_pos = 0;
576 	} else {
577 		length = 1;
578 		raw->line_pos++;
579 	}
580 	raw3215_make_room(raw, length);
581 
582 	for (i = 0; i < length; i++) {
583 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
584 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
585 		raw->count++;
586 	}
587 	if (!(raw->flags & RAW3215_WORKING)) {
588 		raw3215_mk_write_req(raw);
589 		/* start or queue request */
590 		raw3215_try_io(raw);
591 	}
592 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
593 }
594 
595 /*
596  * Flush routine, it simply sets the flush flag and tries to start
597  * pending IO.
598  */
599 static void raw3215_flush_buffer(struct raw3215_info *raw)
600 {
601 	unsigned long flags;
602 
603 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
604 	if (raw->count > 0) {
605 		raw->flags |= RAW3215_FLUSHING;
606 		raw3215_try_io(raw);
607 		raw->flags &= ~RAW3215_FLUSHING;
608 	}
609 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
610 }
611 
612 /*
613  * Fire up a 3215 device.
614  */
615 static int raw3215_startup(struct raw3215_info *raw)
616 {
617 	unsigned long flags;
618 
619 	if (raw->port.flags & ASYNC_INITIALIZED)
620 		return 0;
621 	raw->line_pos = 0;
622 	raw->port.flags |= ASYNC_INITIALIZED;
623 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
624 	raw3215_try_io(raw);
625 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
626 
627 	return 0;
628 }
629 
630 /*
631  * Shutdown a 3215 device.
632  */
633 static void raw3215_shutdown(struct raw3215_info *raw)
634 {
635 	DECLARE_WAITQUEUE(wait, current);
636 	unsigned long flags;
637 
638 	if (!(raw->port.flags & ASYNC_INITIALIZED) ||
639 	    (raw->flags & RAW3215_FIXED))
640 		return;
641 	/* Wait for outstanding requests, then free irq */
642 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
643 	if ((raw->flags & RAW3215_WORKING) ||
644 	    raw->queued_write != NULL ||
645 	    raw->queued_read != NULL) {
646 		add_wait_queue(&raw->empty_wait, &wait);
647 		set_current_state(TASK_INTERRUPTIBLE);
648 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
649 		schedule();
650 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
651 		remove_wait_queue(&raw->empty_wait, &wait);
652 		set_current_state(TASK_RUNNING);
653 		raw->port.flags &= ~ASYNC_INITIALIZED;
654 	}
655 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
656 }
657 
658 static struct raw3215_info *raw3215_alloc_info(void)
659 {
660 	struct raw3215_info *info;
661 
662 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
663 	if (!info)
664 		return NULL;
665 
666 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
667 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
668 	if (!info->buffer || !info->inbuf) {
669 		kfree(info->inbuf);
670 		kfree(info->buffer);
671 		kfree(info);
672 		return NULL;
673 	}
674 
675 	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
676 	init_waitqueue_head(&info->empty_wait);
677 	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
678 	tty_port_init(&info->port);
679 
680 	return info;
681 }
682 
683 static void raw3215_free_info(struct raw3215_info *raw)
684 {
685 	kfree(raw->inbuf);
686 	kfree(raw->buffer);
687 	tty_port_destroy(&raw->port);
688 	kfree(raw);
689 }
690 
691 static int raw3215_probe (struct ccw_device *cdev)
692 {
693 	struct raw3215_info *raw;
694 	int line;
695 
696 	/* Console is special. */
697 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
698 		return 0;
699 
700 	raw = raw3215_alloc_info();
701 	if (raw == NULL)
702 		return -ENOMEM;
703 
704 	raw->cdev = cdev;
705 	dev_set_drvdata(&cdev->dev, raw);
706 	cdev->handler = raw3215_irq;
707 
708 	spin_lock(&raw3215_device_lock);
709 	for (line = 0; line < NR_3215; line++) {
710 		if (!raw3215[line]) {
711 			raw3215[line] = raw;
712 			break;
713 		}
714 	}
715 	spin_unlock(&raw3215_device_lock);
716 	if (line == NR_3215) {
717 		raw3215_free_info(raw);
718 		return -ENODEV;
719 	}
720 
721 	return 0;
722 }
723 
724 static void raw3215_remove (struct ccw_device *cdev)
725 {
726 	struct raw3215_info *raw;
727 	unsigned int line;
728 
729 	ccw_device_set_offline(cdev);
730 	raw = dev_get_drvdata(&cdev->dev);
731 	if (raw) {
732 		spin_lock(&raw3215_device_lock);
733 		for (line = 0; line < NR_3215; line++)
734 			if (raw3215[line] == raw)
735 				break;
736 		raw3215[line] = NULL;
737 		spin_unlock(&raw3215_device_lock);
738 		dev_set_drvdata(&cdev->dev, NULL);
739 		raw3215_free_info(raw);
740 	}
741 }
742 
743 static int raw3215_set_online (struct ccw_device *cdev)
744 {
745 	struct raw3215_info *raw;
746 
747 	raw = dev_get_drvdata(&cdev->dev);
748 	if (!raw)
749 		return -ENODEV;
750 
751 	return raw3215_startup(raw);
752 }
753 
754 static int raw3215_set_offline (struct ccw_device *cdev)
755 {
756 	struct raw3215_info *raw;
757 
758 	raw = dev_get_drvdata(&cdev->dev);
759 	if (!raw)
760 		return -ENODEV;
761 
762 	raw3215_shutdown(raw);
763 
764 	return 0;
765 }
766 
767 static int raw3215_pm_stop(struct ccw_device *cdev)
768 {
769 	struct raw3215_info *raw;
770 	unsigned long flags;
771 
772 	/* Empty the output buffer, then prevent new I/O. */
773 	raw = dev_get_drvdata(&cdev->dev);
774 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
775 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
776 	raw->port.flags |= ASYNC_SUSPENDED;
777 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
778 	return 0;
779 }
780 
781 static int raw3215_pm_start(struct ccw_device *cdev)
782 {
783 	struct raw3215_info *raw;
784 	unsigned long flags;
785 
786 	/* Allow I/O again and flush output buffer. */
787 	raw = dev_get_drvdata(&cdev->dev);
788 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
789 	raw->port.flags &= ~ASYNC_SUSPENDED;
790 	raw->flags |= RAW3215_FLUSHING;
791 	raw3215_try_io(raw);
792 	raw->flags &= ~RAW3215_FLUSHING;
793 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
794 	return 0;
795 }
796 
797 static struct ccw_device_id raw3215_id[] = {
798 	{ CCW_DEVICE(0x3215, 0) },
799 	{ /* end of list */ },
800 };
801 
802 static struct ccw_driver raw3215_ccw_driver = {
803 	.driver = {
804 		.name	= "3215",
805 		.owner	= THIS_MODULE,
806 	},
807 	.ids		= raw3215_id,
808 	.probe		= &raw3215_probe,
809 	.remove		= &raw3215_remove,
810 	.set_online	= &raw3215_set_online,
811 	.set_offline	= &raw3215_set_offline,
812 	.freeze		= &raw3215_pm_stop,
813 	.thaw		= &raw3215_pm_start,
814 	.restore	= &raw3215_pm_start,
815 	.int_class	= IRQIO_C15,
816 };
817 
818 #ifdef CONFIG_TN3215_CONSOLE
819 /*
820  * Write a string to the 3215 console
821  */
822 static void con3215_write(struct console *co, const char *str,
823 			  unsigned int count)
824 {
825 	struct raw3215_info *raw;
826 	int i;
827 
828 	if (count <= 0)
829 		return;
830 	raw = raw3215[0];	/* console 3215 is the first one */
831 	while (count > 0) {
832 		for (i = 0; i < count; i++)
833 			if (str[i] == '\t' || str[i] == '\n')
834 				break;
835 		raw3215_write(raw, str, i);
836 		count -= i;
837 		str += i;
838 		if (count > 0) {
839 			raw3215_putchar(raw, *str);
840 			count--;
841 			str++;
842 		}
843 	}
844 }
845 
846 static struct tty_driver *con3215_device(struct console *c, int *index)
847 {
848 	*index = c->index;
849 	return tty3215_driver;
850 }
851 
852 /*
853  * panic() calls con3215_flush through a panic_notifier
854  * before the system enters a disabled, endless loop.
855  */
856 static void con3215_flush(void)
857 {
858 	struct raw3215_info *raw;
859 	unsigned long flags;
860 
861 	raw = raw3215[0];  /* console 3215 is the first one */
862 	if (raw->port.flags & ASYNC_SUSPENDED)
863 		/* The console is still frozen for suspend. */
864 		if (ccw_device_force_console(raw->cdev))
865 			/* Forcing didn't work, no panic message .. */
866 			return;
867 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
868 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
869 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
870 }
871 
872 static int con3215_notify(struct notifier_block *self,
873 			  unsigned long event, void *data)
874 {
875 	con3215_flush();
876 	return NOTIFY_OK;
877 }
878 
879 static struct notifier_block on_panic_nb = {
880 	.notifier_call = con3215_notify,
881 	.priority = 0,
882 };
883 
884 static struct notifier_block on_reboot_nb = {
885 	.notifier_call = con3215_notify,
886 	.priority = 0,
887 };
888 
889 /*
890  *  The console structure for the 3215 console
891  */
892 static struct console con3215 = {
893 	.name	 = "ttyS",
894 	.write	 = con3215_write,
895 	.device	 = con3215_device,
896 	.flags	 = CON_PRINTBUFFER,
897 };
898 
899 /*
900  * 3215 console initialization code called from console_init().
901  */
902 static int __init con3215_init(void)
903 {
904 	struct ccw_device *cdev;
905 	struct raw3215_info *raw;
906 	struct raw3215_req *req;
907 	int i;
908 
909 	/* Check if 3215 is to be the console */
910 	if (!CONSOLE_IS_3215)
911 		return -ENODEV;
912 
913 	/* Set the console mode for VM */
914 	if (MACHINE_IS_VM) {
915 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
916 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
917 	}
918 
919 	/* allocate 3215 request structures */
920 	raw3215_freelist = NULL;
921 	spin_lock_init(&raw3215_freelist_lock);
922 	for (i = 0; i < NR_3215_REQ; i++) {
923 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
924 		if (!req)
925 			return -ENOMEM;
926 		req->next = raw3215_freelist;
927 		raw3215_freelist = req;
928 	}
929 
930 	cdev = ccw_device_create_console(&raw3215_ccw_driver);
931 	if (IS_ERR(cdev))
932 		return -ENODEV;
933 
934 	raw3215[0] = raw = raw3215_alloc_info();
935 	raw->cdev = cdev;
936 	dev_set_drvdata(&cdev->dev, raw);
937 	cdev->handler = raw3215_irq;
938 
939 	raw->flags |= RAW3215_FIXED;
940 	if (ccw_device_enable_console(cdev)) {
941 		ccw_device_destroy_console(cdev);
942 		raw3215_free_info(raw);
943 		raw3215[0] = NULL;
944 		return -ENODEV;
945 	}
946 
947 	/* Request the console irq */
948 	if (raw3215_startup(raw) != 0) {
949 		raw3215_free_info(raw);
950 		raw3215[0] = NULL;
951 		return -ENODEV;
952 	}
953 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
954 	register_reboot_notifier(&on_reboot_nb);
955 	register_console(&con3215);
956 	return 0;
957 }
958 console_initcall(con3215_init);
959 #endif
960 
961 static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
962 {
963 	struct raw3215_info *raw;
964 
965 	raw = raw3215[tty->index];
966 	if (raw == NULL)
967 		return -ENODEV;
968 
969 	tty->driver_data = raw;
970 
971 	return tty_port_install(&raw->port, driver, tty);
972 }
973 
974 /*
975  * tty3215_open
976  *
977  * This routine is called whenever a 3215 tty is opened.
978  */
979 static int tty3215_open(struct tty_struct *tty, struct file * filp)
980 {
981 	struct raw3215_info *raw = tty->driver_data;
982 	int retval;
983 
984 	tty_port_tty_set(&raw->port, tty);
985 
986 	raw->port.low_latency = 0; /* don't use bottom half for pushing chars */
987 	/*
988 	 * Start up 3215 device
989 	 */
990 	retval = raw3215_startup(raw);
991 	if (retval)
992 		return retval;
993 
994 	return 0;
995 }
996 
997 /*
998  * tty3215_close()
999  *
1000  * This routine is called when the 3215 tty is closed. We wait
1001  * for the remaining request to be completed. Then we clean up.
1002  */
1003 static void tty3215_close(struct tty_struct *tty, struct file * filp)
1004 {
1005 	struct raw3215_info *raw;
1006 
1007 	raw = (struct raw3215_info *) tty->driver_data;
1008 	if (raw == NULL || tty->count > 1)
1009 		return;
1010 	tty->closing = 1;
1011 	/* Shutdown the terminal */
1012 	raw3215_shutdown(raw);
1013 	tasklet_kill(&raw->tlet);
1014 	tty->closing = 0;
1015 	tty_port_tty_set(&raw->port, NULL);
1016 }
1017 
1018 /*
1019  * Returns the amount of free space in the output buffer.
1020  */
1021 static int tty3215_write_room(struct tty_struct *tty)
1022 {
1023 	struct raw3215_info *raw;
1024 
1025 	raw = (struct raw3215_info *) tty->driver_data;
1026 
1027 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1028 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1029 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1030 	else
1031 		return 0;
1032 }
1033 
1034 /*
1035  * String write routine for 3215 ttys
1036  */
1037 static int tty3215_write(struct tty_struct * tty,
1038 			 const unsigned char *buf, int count)
1039 {
1040 	struct raw3215_info *raw;
1041 	int i, written;
1042 
1043 	if (!tty)
1044 		return 0;
1045 	raw = (struct raw3215_info *) tty->driver_data;
1046 	written = count;
1047 	while (count > 0) {
1048 		for (i = 0; i < count; i++)
1049 			if (buf[i] == '\t' || buf[i] == '\n')
1050 				break;
1051 		raw3215_write(raw, buf, i);
1052 		count -= i;
1053 		buf += i;
1054 		if (count > 0) {
1055 			raw3215_putchar(raw, *buf);
1056 			count--;
1057 			buf++;
1058 		}
1059 	}
1060 	return written;
1061 }
1062 
1063 /*
1064  * Put character routine for 3215 ttys
1065  */
1066 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1067 {
1068 	struct raw3215_info *raw;
1069 
1070 	if (!tty)
1071 		return 0;
1072 	raw = (struct raw3215_info *) tty->driver_data;
1073 	raw3215_putchar(raw, ch);
1074 	return 1;
1075 }
1076 
1077 static void tty3215_flush_chars(struct tty_struct *tty)
1078 {
1079 }
1080 
1081 /*
1082  * Returns the number of characters in the output buffer
1083  */
1084 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1085 {
1086 	struct raw3215_info *raw;
1087 
1088 	raw = (struct raw3215_info *) tty->driver_data;
1089 	return raw->count;
1090 }
1091 
1092 static void tty3215_flush_buffer(struct tty_struct *tty)
1093 {
1094 	struct raw3215_info *raw;
1095 
1096 	raw = (struct raw3215_info *) tty->driver_data;
1097 	raw3215_flush_buffer(raw);
1098 	tty_wakeup(tty);
1099 }
1100 
1101 /*
1102  * Disable reading from a 3215 tty
1103  */
1104 static void tty3215_throttle(struct tty_struct * tty)
1105 {
1106 	struct raw3215_info *raw;
1107 
1108 	raw = (struct raw3215_info *) tty->driver_data;
1109 	raw->flags |= RAW3215_THROTTLED;
1110 }
1111 
1112 /*
1113  * Enable reading from a 3215 tty
1114  */
1115 static void tty3215_unthrottle(struct tty_struct * tty)
1116 {
1117 	struct raw3215_info *raw;
1118 	unsigned long flags;
1119 
1120 	raw = (struct raw3215_info *) tty->driver_data;
1121 	if (raw->flags & RAW3215_THROTTLED) {
1122 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1123 		raw->flags &= ~RAW3215_THROTTLED;
1124 		raw3215_try_io(raw);
1125 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1126 	}
1127 }
1128 
1129 /*
1130  * Disable writing to a 3215 tty
1131  */
1132 static void tty3215_stop(struct tty_struct *tty)
1133 {
1134 	struct raw3215_info *raw;
1135 
1136 	raw = (struct raw3215_info *) tty->driver_data;
1137 	raw->flags |= RAW3215_STOPPED;
1138 }
1139 
1140 /*
1141  * Enable writing to a 3215 tty
1142  */
1143 static void tty3215_start(struct tty_struct *tty)
1144 {
1145 	struct raw3215_info *raw;
1146 	unsigned long flags;
1147 
1148 	raw = (struct raw3215_info *) tty->driver_data;
1149 	if (raw->flags & RAW3215_STOPPED) {
1150 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1151 		raw->flags &= ~RAW3215_STOPPED;
1152 		raw3215_try_io(raw);
1153 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1154 	}
1155 }
1156 
1157 static const struct tty_operations tty3215_ops = {
1158 	.install = tty3215_install,
1159 	.open = tty3215_open,
1160 	.close = tty3215_close,
1161 	.write = tty3215_write,
1162 	.put_char = tty3215_put_char,
1163 	.flush_chars = tty3215_flush_chars,
1164 	.write_room = tty3215_write_room,
1165 	.chars_in_buffer = tty3215_chars_in_buffer,
1166 	.flush_buffer = tty3215_flush_buffer,
1167 	.throttle = tty3215_throttle,
1168 	.unthrottle = tty3215_unthrottle,
1169 	.stop = tty3215_stop,
1170 	.start = tty3215_start,
1171 };
1172 
1173 /*
1174  * 3215 tty registration code called from tty_init().
1175  * Most kernel services (incl. kmalloc) are available at this poimt.
1176  */
1177 static int __init tty3215_init(void)
1178 {
1179 	struct tty_driver *driver;
1180 	int ret;
1181 
1182 	if (!CONSOLE_IS_3215)
1183 		return 0;
1184 
1185 	driver = alloc_tty_driver(NR_3215);
1186 	if (!driver)
1187 		return -ENOMEM;
1188 
1189 	ret = ccw_driver_register(&raw3215_ccw_driver);
1190 	if (ret) {
1191 		put_tty_driver(driver);
1192 		return ret;
1193 	}
1194 	/*
1195 	 * Initialize the tty_driver structure
1196 	 * Entries in tty3215_driver that are NOT initialized:
1197 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1198 	 */
1199 
1200 	driver->driver_name = "tty3215";
1201 	driver->name = "ttyS";
1202 	driver->major = TTY_MAJOR;
1203 	driver->minor_start = 64;
1204 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1205 	driver->subtype = SYSTEM_TYPE_TTY;
1206 	driver->init_termios = tty_std_termios;
1207 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1208 	driver->init_termios.c_oflag = ONLCR;
1209 	driver->init_termios.c_lflag = ISIG;
1210 	driver->flags = TTY_DRIVER_REAL_RAW;
1211 	tty_set_operations(driver, &tty3215_ops);
1212 	ret = tty_register_driver(driver);
1213 	if (ret) {
1214 		put_tty_driver(driver);
1215 		return ret;
1216 	}
1217 	tty3215_driver = driver;
1218 	return 0;
1219 }
1220 
1221 static void __exit tty3215_exit(void)
1222 {
1223 	tty_unregister_driver(tty3215_driver);
1224 	put_tty_driver(tty3215_driver);
1225 	ccw_driver_unregister(&raw3215_ccw_driver);
1226 }
1227 
1228 module_init(tty3215_init);
1229 module_exit(tty3215_exit);
1230