xref: /openbmc/linux/drivers/s390/char/con3215.c (revision c6fddb28)
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 		fallthrough;
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 (tty_port_suspended(&raw->port)) {
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 (tty_port_initialized(&raw->port))
620 		return 0;
621 	raw->line_pos = 0;
622 	tty_port_set_initialized(&raw->port, 1);
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 (!tty_port_initialized(&raw->port) || (raw->flags & RAW3215_FIXED))
639 		return;
640 	/* Wait for outstanding requests, then free irq */
641 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
642 	if ((raw->flags & RAW3215_WORKING) ||
643 	    raw->queued_write != NULL ||
644 	    raw->queued_read != NULL) {
645 		add_wait_queue(&raw->empty_wait, &wait);
646 		set_current_state(TASK_INTERRUPTIBLE);
647 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
648 		schedule();
649 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
650 		remove_wait_queue(&raw->empty_wait, &wait);
651 		set_current_state(TASK_RUNNING);
652 		tty_port_set_initialized(&raw->port, 1);
653 	}
654 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
655 }
656 
657 static struct raw3215_info *raw3215_alloc_info(void)
658 {
659 	struct raw3215_info *info;
660 
661 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
662 	if (!info)
663 		return NULL;
664 
665 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
666 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
667 	if (!info->buffer || !info->inbuf) {
668 		kfree(info->inbuf);
669 		kfree(info->buffer);
670 		kfree(info);
671 		return NULL;
672 	}
673 
674 	timer_setup(&info->timer, raw3215_timeout, 0);
675 	init_waitqueue_head(&info->empty_wait);
676 	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
677 	tty_port_init(&info->port);
678 
679 	return info;
680 }
681 
682 static void raw3215_free_info(struct raw3215_info *raw)
683 {
684 	kfree(raw->inbuf);
685 	kfree(raw->buffer);
686 	tty_port_destroy(&raw->port);
687 	kfree(raw);
688 }
689 
690 static int raw3215_probe (struct ccw_device *cdev)
691 {
692 	struct raw3215_info *raw;
693 	int line;
694 
695 	/* Console is special. */
696 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
697 		return 0;
698 
699 	raw = raw3215_alloc_info();
700 	if (raw == NULL)
701 		return -ENOMEM;
702 
703 	raw->cdev = cdev;
704 	dev_set_drvdata(&cdev->dev, raw);
705 	cdev->handler = raw3215_irq;
706 
707 	spin_lock(&raw3215_device_lock);
708 	for (line = 0; line < NR_3215; line++) {
709 		if (!raw3215[line]) {
710 			raw3215[line] = raw;
711 			break;
712 		}
713 	}
714 	spin_unlock(&raw3215_device_lock);
715 	if (line == NR_3215) {
716 		raw3215_free_info(raw);
717 		return -ENODEV;
718 	}
719 
720 	return 0;
721 }
722 
723 static void raw3215_remove (struct ccw_device *cdev)
724 {
725 	struct raw3215_info *raw;
726 	unsigned int line;
727 
728 	ccw_device_set_offline(cdev);
729 	raw = dev_get_drvdata(&cdev->dev);
730 	if (raw) {
731 		spin_lock(&raw3215_device_lock);
732 		for (line = 0; line < NR_3215; line++)
733 			if (raw3215[line] == raw)
734 				break;
735 		raw3215[line] = NULL;
736 		spin_unlock(&raw3215_device_lock);
737 		dev_set_drvdata(&cdev->dev, NULL);
738 		raw3215_free_info(raw);
739 	}
740 }
741 
742 static int raw3215_set_online (struct ccw_device *cdev)
743 {
744 	struct raw3215_info *raw;
745 
746 	raw = dev_get_drvdata(&cdev->dev);
747 	if (!raw)
748 		return -ENODEV;
749 
750 	return raw3215_startup(raw);
751 }
752 
753 static int raw3215_set_offline (struct ccw_device *cdev)
754 {
755 	struct raw3215_info *raw;
756 
757 	raw = dev_get_drvdata(&cdev->dev);
758 	if (!raw)
759 		return -ENODEV;
760 
761 	raw3215_shutdown(raw);
762 
763 	return 0;
764 }
765 
766 static int raw3215_pm_stop(struct ccw_device *cdev)
767 {
768 	struct raw3215_info *raw;
769 	unsigned long flags;
770 
771 	/* Empty the output buffer, then prevent new I/O. */
772 	raw = dev_get_drvdata(&cdev->dev);
773 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
774 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
775 	tty_port_set_suspended(&raw->port, 1);
776 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
777 	return 0;
778 }
779 
780 static int raw3215_pm_start(struct ccw_device *cdev)
781 {
782 	struct raw3215_info *raw;
783 	unsigned long flags;
784 
785 	/* Allow I/O again and flush output buffer. */
786 	raw = dev_get_drvdata(&cdev->dev);
787 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
788 	tty_port_set_suspended(&raw->port, 0);
789 	raw->flags |= RAW3215_FLUSHING;
790 	raw3215_try_io(raw);
791 	raw->flags &= ~RAW3215_FLUSHING;
792 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
793 	return 0;
794 }
795 
796 static struct ccw_device_id raw3215_id[] = {
797 	{ CCW_DEVICE(0x3215, 0) },
798 	{ /* end of list */ },
799 };
800 
801 static struct ccw_driver raw3215_ccw_driver = {
802 	.driver = {
803 		.name	= "3215",
804 		.owner	= THIS_MODULE,
805 	},
806 	.ids		= raw3215_id,
807 	.probe		= &raw3215_probe,
808 	.remove		= &raw3215_remove,
809 	.set_online	= &raw3215_set_online,
810 	.set_offline	= &raw3215_set_offline,
811 	.freeze		= &raw3215_pm_stop,
812 	.thaw		= &raw3215_pm_start,
813 	.restore	= &raw3215_pm_start,
814 	.int_class	= IRQIO_C15,
815 };
816 
817 #ifdef CONFIG_TN3215_CONSOLE
818 /*
819  * Write a string to the 3215 console
820  */
821 static void con3215_write(struct console *co, const char *str,
822 			  unsigned int count)
823 {
824 	struct raw3215_info *raw;
825 	int i;
826 
827 	if (count <= 0)
828 		return;
829 	raw = raw3215[0];	/* console 3215 is the first one */
830 	while (count > 0) {
831 		for (i = 0; i < count; i++)
832 			if (str[i] == '\t' || str[i] == '\n')
833 				break;
834 		raw3215_write(raw, str, i);
835 		count -= i;
836 		str += i;
837 		if (count > 0) {
838 			raw3215_putchar(raw, *str);
839 			count--;
840 			str++;
841 		}
842 	}
843 }
844 
845 static struct tty_driver *con3215_device(struct console *c, int *index)
846 {
847 	*index = c->index;
848 	return tty3215_driver;
849 }
850 
851 /*
852  * panic() calls con3215_flush through a panic_notifier
853  * before the system enters a disabled, endless loop.
854  */
855 static void con3215_flush(void)
856 {
857 	struct raw3215_info *raw;
858 	unsigned long flags;
859 
860 	raw = raw3215[0];  /* console 3215 is the first one */
861 	if (tty_port_suspended(&raw->port))
862 		/* The console is still frozen for suspend. */
863 		if (ccw_device_force_console(raw->cdev))
864 			/* Forcing didn't work, no panic message .. */
865 			return;
866 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
867 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
868 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
869 }
870 
871 static int con3215_notify(struct notifier_block *self,
872 			  unsigned long event, void *data)
873 {
874 	con3215_flush();
875 	return NOTIFY_OK;
876 }
877 
878 static struct notifier_block on_panic_nb = {
879 	.notifier_call = con3215_notify,
880 	.priority = 0,
881 };
882 
883 static struct notifier_block on_reboot_nb = {
884 	.notifier_call = con3215_notify,
885 	.priority = 0,
886 };
887 
888 /*
889  *  The console structure for the 3215 console
890  */
891 static struct console con3215 = {
892 	.name	 = "ttyS",
893 	.write	 = con3215_write,
894 	.device	 = con3215_device,
895 	.flags	 = CON_PRINTBUFFER,
896 };
897 
898 /*
899  * 3215 console initialization code called from console_init().
900  */
901 static int __init con3215_init(void)
902 {
903 	struct ccw_device *cdev;
904 	struct raw3215_info *raw;
905 	struct raw3215_req *req;
906 	int i;
907 
908 	/* Check if 3215 is to be the console */
909 	if (!CONSOLE_IS_3215)
910 		return -ENODEV;
911 
912 	/* Set the console mode for VM */
913 	if (MACHINE_IS_VM) {
914 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
915 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
916 	}
917 
918 	/* allocate 3215 request structures */
919 	raw3215_freelist = NULL;
920 	spin_lock_init(&raw3215_freelist_lock);
921 	for (i = 0; i < NR_3215_REQ; i++) {
922 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
923 		if (!req)
924 			return -ENOMEM;
925 		req->next = raw3215_freelist;
926 		raw3215_freelist = req;
927 	}
928 
929 	cdev = ccw_device_create_console(&raw3215_ccw_driver);
930 	if (IS_ERR(cdev))
931 		return -ENODEV;
932 
933 	raw3215[0] = raw = raw3215_alloc_info();
934 	raw->cdev = cdev;
935 	dev_set_drvdata(&cdev->dev, raw);
936 	cdev->handler = raw3215_irq;
937 
938 	raw->flags |= RAW3215_FIXED;
939 	if (ccw_device_enable_console(cdev)) {
940 		ccw_device_destroy_console(cdev);
941 		raw3215_free_info(raw);
942 		raw3215[0] = NULL;
943 		return -ENODEV;
944 	}
945 
946 	/* Request the console irq */
947 	if (raw3215_startup(raw) != 0) {
948 		raw3215_free_info(raw);
949 		raw3215[0] = NULL;
950 		return -ENODEV;
951 	}
952 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
953 	register_reboot_notifier(&on_reboot_nb);
954 	register_console(&con3215);
955 	return 0;
956 }
957 console_initcall(con3215_init);
958 #endif
959 
960 static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
961 {
962 	struct raw3215_info *raw;
963 
964 	raw = raw3215[tty->index];
965 	if (raw == NULL)
966 		return -ENODEV;
967 
968 	tty->driver_data = raw;
969 
970 	return tty_port_install(&raw->port, driver, tty);
971 }
972 
973 /*
974  * tty3215_open
975  *
976  * This routine is called whenever a 3215 tty is opened.
977  */
978 static int tty3215_open(struct tty_struct *tty, struct file * filp)
979 {
980 	struct raw3215_info *raw = tty->driver_data;
981 	int retval;
982 
983 	tty_port_tty_set(&raw->port, tty);
984 
985 	raw->port.low_latency = 0; /* don't use bottom half for pushing chars */
986 	/*
987 	 * Start up 3215 device
988 	 */
989 	retval = raw3215_startup(raw);
990 	if (retval)
991 		return retval;
992 
993 	return 0;
994 }
995 
996 /*
997  * tty3215_close()
998  *
999  * This routine is called when the 3215 tty is closed. We wait
1000  * for the remaining request to be completed. Then we clean up.
1001  */
1002 static void tty3215_close(struct tty_struct *tty, struct file * filp)
1003 {
1004 	struct raw3215_info *raw;
1005 
1006 	raw = (struct raw3215_info *) tty->driver_data;
1007 	if (raw == NULL || tty->count > 1)
1008 		return;
1009 	tty->closing = 1;
1010 	/* Shutdown the terminal */
1011 	raw3215_shutdown(raw);
1012 	tasklet_kill(&raw->tlet);
1013 	tty->closing = 0;
1014 	tty_port_tty_set(&raw->port, NULL);
1015 }
1016 
1017 /*
1018  * Returns the amount of free space in the output buffer.
1019  */
1020 static int tty3215_write_room(struct tty_struct *tty)
1021 {
1022 	struct raw3215_info *raw;
1023 
1024 	raw = (struct raw3215_info *) tty->driver_data;
1025 
1026 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1027 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1028 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1029 	else
1030 		return 0;
1031 }
1032 
1033 /*
1034  * String write routine for 3215 ttys
1035  */
1036 static int tty3215_write(struct tty_struct * tty,
1037 			 const unsigned char *buf, int count)
1038 {
1039 	struct raw3215_info *raw;
1040 	int i, written;
1041 
1042 	if (!tty)
1043 		return 0;
1044 	raw = (struct raw3215_info *) tty->driver_data;
1045 	written = count;
1046 	while (count > 0) {
1047 		for (i = 0; i < count; i++)
1048 			if (buf[i] == '\t' || buf[i] == '\n')
1049 				break;
1050 		raw3215_write(raw, buf, i);
1051 		count -= i;
1052 		buf += i;
1053 		if (count > 0) {
1054 			raw3215_putchar(raw, *buf);
1055 			count--;
1056 			buf++;
1057 		}
1058 	}
1059 	return written;
1060 }
1061 
1062 /*
1063  * Put character routine for 3215 ttys
1064  */
1065 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1066 {
1067 	struct raw3215_info *raw;
1068 
1069 	if (!tty)
1070 		return 0;
1071 	raw = (struct raw3215_info *) tty->driver_data;
1072 	raw3215_putchar(raw, ch);
1073 	return 1;
1074 }
1075 
1076 static void tty3215_flush_chars(struct tty_struct *tty)
1077 {
1078 }
1079 
1080 /*
1081  * Returns the number of characters in the output buffer
1082  */
1083 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1084 {
1085 	struct raw3215_info *raw;
1086 
1087 	raw = (struct raw3215_info *) tty->driver_data;
1088 	return raw->count;
1089 }
1090 
1091 static void tty3215_flush_buffer(struct tty_struct *tty)
1092 {
1093 	struct raw3215_info *raw;
1094 
1095 	raw = (struct raw3215_info *) tty->driver_data;
1096 	raw3215_flush_buffer(raw);
1097 	tty_wakeup(tty);
1098 }
1099 
1100 /*
1101  * Disable reading from a 3215 tty
1102  */
1103 static void tty3215_throttle(struct tty_struct * tty)
1104 {
1105 	struct raw3215_info *raw;
1106 
1107 	raw = (struct raw3215_info *) tty->driver_data;
1108 	raw->flags |= RAW3215_THROTTLED;
1109 }
1110 
1111 /*
1112  * Enable reading from a 3215 tty
1113  */
1114 static void tty3215_unthrottle(struct tty_struct * tty)
1115 {
1116 	struct raw3215_info *raw;
1117 	unsigned long flags;
1118 
1119 	raw = (struct raw3215_info *) tty->driver_data;
1120 	if (raw->flags & RAW3215_THROTTLED) {
1121 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1122 		raw->flags &= ~RAW3215_THROTTLED;
1123 		raw3215_try_io(raw);
1124 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1125 	}
1126 }
1127 
1128 /*
1129  * Disable writing to a 3215 tty
1130  */
1131 static void tty3215_stop(struct tty_struct *tty)
1132 {
1133 	struct raw3215_info *raw;
1134 
1135 	raw = (struct raw3215_info *) tty->driver_data;
1136 	raw->flags |= RAW3215_STOPPED;
1137 }
1138 
1139 /*
1140  * Enable writing to a 3215 tty
1141  */
1142 static void tty3215_start(struct tty_struct *tty)
1143 {
1144 	struct raw3215_info *raw;
1145 	unsigned long flags;
1146 
1147 	raw = (struct raw3215_info *) tty->driver_data;
1148 	if (raw->flags & RAW3215_STOPPED) {
1149 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1150 		raw->flags &= ~RAW3215_STOPPED;
1151 		raw3215_try_io(raw);
1152 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1153 	}
1154 }
1155 
1156 static const struct tty_operations tty3215_ops = {
1157 	.install = tty3215_install,
1158 	.open = tty3215_open,
1159 	.close = tty3215_close,
1160 	.write = tty3215_write,
1161 	.put_char = tty3215_put_char,
1162 	.flush_chars = tty3215_flush_chars,
1163 	.write_room = tty3215_write_room,
1164 	.chars_in_buffer = tty3215_chars_in_buffer,
1165 	.flush_buffer = tty3215_flush_buffer,
1166 	.throttle = tty3215_throttle,
1167 	.unthrottle = tty3215_unthrottle,
1168 	.stop = tty3215_stop,
1169 	.start = tty3215_start,
1170 };
1171 
1172 /*
1173  * 3215 tty registration code called from tty_init().
1174  * Most kernel services (incl. kmalloc) are available at this poimt.
1175  */
1176 static int __init tty3215_init(void)
1177 {
1178 	struct tty_driver *driver;
1179 	int ret;
1180 
1181 	if (!CONSOLE_IS_3215)
1182 		return 0;
1183 
1184 	driver = alloc_tty_driver(NR_3215);
1185 	if (!driver)
1186 		return -ENOMEM;
1187 
1188 	ret = ccw_driver_register(&raw3215_ccw_driver);
1189 	if (ret) {
1190 		put_tty_driver(driver);
1191 		return ret;
1192 	}
1193 	/*
1194 	 * Initialize the tty_driver structure
1195 	 * Entries in tty3215_driver that are NOT initialized:
1196 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1197 	 */
1198 
1199 	driver->driver_name = "tty3215";
1200 	driver->name = "ttyS";
1201 	driver->major = TTY_MAJOR;
1202 	driver->minor_start = 64;
1203 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1204 	driver->subtype = SYSTEM_TYPE_TTY;
1205 	driver->init_termios = tty_std_termios;
1206 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1207 	driver->init_termios.c_oflag = ONLCR;
1208 	driver->init_termios.c_lflag = ISIG;
1209 	driver->flags = TTY_DRIVER_REAL_RAW;
1210 	tty_set_operations(driver, &tty3215_ops);
1211 	ret = tty_register_driver(driver);
1212 	if (ret) {
1213 		put_tty_driver(driver);
1214 		return ret;
1215 	}
1216 	tty3215_driver = driver;
1217 	return 0;
1218 }
1219 device_initcall(tty3215_init);
1220