xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 64c70b1c)
1 /*
2  *  drivers/s390/char/con3215.c
3  *    3215 line mode terminal driver.
4  *
5  *  S390 version
6  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
7  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
8  *
9  *  Updated:
10  *   Aug-2000: Added tab support
11  *	       Dan Morrison, IBM Corporation (dmorriso@cse.buffalo.edu)
12  */
13 
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/kdev_t.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/vt_kern.h>
20 #include <linux/init.h>
21 #include <linux/console.h>
22 #include <linux/interrupt.h>
23 #include <linux/err.h>
24 
25 #include <linux/slab.h>
26 #include <linux/bootmem.h>
27 
28 #include <asm/ccwdev.h>
29 #include <asm/cio.h>
30 #include <asm/io.h>
31 #include <asm/ebcdic.h>
32 #include <asm/uaccess.h>
33 #include <asm/delay.h>
34 #include <asm/cpcmd.h>
35 #include <asm/setup.h>
36 
37 #include "ctrlchar.h"
38 
39 #define NR_3215		    1
40 #define NR_3215_REQ	    (4*NR_3215)
41 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
42 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
43 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
44 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
45 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
46 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
47 #define RAW3215_NR_CCWS	    3
48 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
49 
50 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
51 #define RAW3215_ACTIVE	    2	      /* set if the device is in use */
52 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
53 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
54 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
55 #define RAW3215_CLOSING	    32	      /* set while in close process */
56 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
57 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
58 
59 #define TAB_STOP_SIZE	    8	      /* tab stop size */
60 
61 /*
62  * Request types for a 3215 device
63  */
64 enum raw3215_type {
65 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
66 };
67 
68 /*
69  * Request structure for a 3215 device
70  */
71 struct raw3215_req {
72 	enum raw3215_type type;	      /* type of the request */
73 	int start, len;		      /* start index & len in output buffer */
74 	int delayable;		      /* indication to wait for more data */
75 	int residual;		      /* residual count for read request */
76 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
77 	struct raw3215_info *info;    /* pointer to main structure */
78 	struct raw3215_req *next;     /* pointer to next request */
79 } __attribute__ ((aligned(8)));
80 
81 struct raw3215_info {
82 	struct ccw_device *cdev;      /* device for tty driver */
83 	spinlock_t *lock;	      /* pointer to irq lock */
84 	int flags;		      /* state flags */
85 	char *buffer;		      /* pointer to output buffer */
86 	char *inbuf;		      /* pointer to input buffer */
87 	int head;		      /* first free byte in output buffer */
88 	int count;		      /* number of bytes in output buffer */
89 	int written;		      /* number of bytes in write requests */
90 	struct tty_struct *tty;	      /* pointer to tty structure if present */
91 	struct tasklet_struct tasklet;
92 	struct raw3215_req *queued_read; /* pointer to queued read requests */
93 	struct raw3215_req *queued_write;/* pointer to queued write requests */
94 	wait_queue_head_t empty_wait; /* wait queue for flushing */
95 	struct timer_list timer;      /* timer for delayed output */
96 	char *message;		      /* pending message from raw3215_irq */
97 	int msg_dstat;		      /* dstat for pending message */
98 	int msg_cstat;		      /* cstat for pending message */
99 	int line_pos;		      /* position on the line (for tabs) */
100 	char ubuffer[80];	      /* copy_from_user buffer */
101 };
102 
103 /* array of 3215 devices structures */
104 static struct raw3215_info *raw3215[NR_3215];
105 /* spinlock to protect the raw3215 array */
106 static DEFINE_SPINLOCK(raw3215_device_lock);
107 /* list of free request structures */
108 static struct raw3215_req *raw3215_freelist;
109 /* spinlock to protect free list */
110 static spinlock_t raw3215_freelist_lock;
111 
112 static struct tty_driver *tty3215_driver;
113 
114 /*
115  * Get a request structure from the free list
116  */
117 static inline struct raw3215_req *
118 raw3215_alloc_req(void) {
119 	struct raw3215_req *req;
120 	unsigned long flags;
121 
122 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
123 	req = raw3215_freelist;
124 	raw3215_freelist = req->next;
125 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
126 	return req;
127 }
128 
129 /*
130  * Put a request structure back to the free list
131  */
132 static inline void
133 raw3215_free_req(struct raw3215_req *req) {
134 	unsigned long flags;
135 
136 	if (req->type == RAW3215_FREE)
137 		return;		/* don't free a free request */
138 	req->type = RAW3215_FREE;
139 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
140 	req->next = raw3215_freelist;
141 	raw3215_freelist = req;
142 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
143 }
144 
145 /*
146  * Set up a read request that reads up to 160 byte from the 3215 device.
147  * If there is a queued read request it is used, but that shouldn't happen
148  * because a 3215 terminal won't accept a new read before the old one is
149  * completed.
150  */
151 static void
152 raw3215_mk_read_req(struct raw3215_info *raw)
153 {
154 	struct raw3215_req *req;
155 	struct ccw1 *ccw;
156 
157 	/* there can only be ONE read request at a time */
158 	req = raw->queued_read;
159 	if (req == NULL) {
160 		/* no queued read request, use new req structure */
161 		req = raw3215_alloc_req();
162 		req->type = RAW3215_READ;
163 		req->info = raw;
164 		raw->queued_read = req;
165 	}
166 
167 	ccw = req->ccws;
168 	ccw->cmd_code = 0x0A; /* read inquiry */
169 	ccw->flags = 0x20;    /* ignore incorrect length */
170 	ccw->count = 160;
171 	ccw->cda = (__u32) __pa(raw->inbuf);
172 }
173 
174 /*
175  * Set up a write request with the information from the main structure.
176  * A ccw chain is created that writes as much as possible from the output
177  * buffer to the 3215 device. If a queued write exists it is replaced by
178  * the new, probably lengthened request.
179  */
180 static void
181 raw3215_mk_write_req(struct raw3215_info *raw)
182 {
183 	struct raw3215_req *req;
184 	struct ccw1 *ccw;
185 	int len, count, ix, lines;
186 
187 	if (raw->count <= raw->written)
188 		return;
189 	/* check if there is a queued write request */
190 	req = raw->queued_write;
191 	if (req == NULL) {
192 		/* no queued write request, use new req structure */
193 		req = raw3215_alloc_req();
194 		req->type = RAW3215_WRITE;
195 		req->info = raw;
196 		raw->queued_write = req;
197 	} else {
198 		raw->written -= req->len;
199 	}
200 
201 	ccw = req->ccws;
202 	req->start = (raw->head - raw->count + raw->written) &
203 		     (RAW3215_BUFFER_SIZE - 1);
204 	/*
205 	 * now we have to count newlines. We can at max accept
206 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
207 	 * a restriction in VM
208 	 */
209 	lines = 0;
210 	ix = req->start;
211 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
212 		if (raw->buffer[ix] == 0x15)
213 			lines++;
214 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
215 	}
216 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
217 	if (len > RAW3215_MAX_BYTES)
218 		len = RAW3215_MAX_BYTES;
219 	req->len = len;
220 	raw->written += len;
221 
222 	/* set the indication if we should try to enlarge this request */
223 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
224 
225 	ix = req->start;
226 	while (len > 0) {
227 		if (ccw > req->ccws)
228 			ccw[-1].flags |= 0x40; /* use command chaining */
229 		ccw->cmd_code = 0x01; /* write, auto carrier return */
230 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
231 		ccw->cda =
232 			(__u32) __pa(raw->buffer + ix);
233 		count = len;
234 		if (ix + count > RAW3215_BUFFER_SIZE)
235 			count = RAW3215_BUFFER_SIZE - ix;
236 		ccw->count = count;
237 		len -= count;
238 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
239 		ccw++;
240 	}
241 	/*
242 	 * Add a NOP to the channel program. 3215 devices are purely
243 	 * emulated and its much better to avoid the channel end
244 	 * interrupt in this case.
245 	 */
246 	if (ccw > req->ccws)
247 		ccw[-1].flags |= 0x40; /* use command chaining */
248 	ccw->cmd_code = 0x03; /* NOP */
249 	ccw->flags = 0;
250 	ccw->cda = 0;
251 	ccw->count = 1;
252 }
253 
254 /*
255  * Start a read or a write request
256  */
257 static void
258 raw3215_start_io(struct raw3215_info *raw)
259 {
260 	struct raw3215_req *req;
261 	int res;
262 
263 	req = raw->queued_read;
264 	if (req != NULL &&
265 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
266 		/* dequeue request */
267 		raw->queued_read = NULL;
268 		res = ccw_device_start(raw->cdev, req->ccws,
269 				       (unsigned long) req, 0, 0);
270 		if (res != 0) {
271 			/* do_IO failed, put request back to queue */
272 			raw->queued_read = req;
273 		} else {
274 			raw->flags |= RAW3215_WORKING;
275 		}
276 	}
277 	req = raw->queued_write;
278 	if (req != NULL &&
279 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
280 		/* dequeue request */
281 		raw->queued_write = NULL;
282 		res = ccw_device_start(raw->cdev, req->ccws,
283 				       (unsigned long) req, 0, 0);
284 		if (res != 0) {
285 			/* do_IO failed, put request back to queue */
286 			raw->queued_write = req;
287 		} else {
288 			raw->flags |= RAW3215_WORKING;
289 		}
290 	}
291 }
292 
293 /*
294  * Function to start a delayed output after RAW3215_TIMEOUT seconds
295  */
296 static void
297 raw3215_timeout(unsigned long __data)
298 {
299 	struct raw3215_info *raw = (struct raw3215_info *) __data;
300 	unsigned long flags;
301 
302 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
303 	if (raw->flags & RAW3215_TIMER_RUNS) {
304 		del_timer(&raw->timer);
305 		raw->flags &= ~RAW3215_TIMER_RUNS;
306 		raw3215_mk_write_req(raw);
307 		raw3215_start_io(raw);
308 	}
309 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
310 }
311 
312 /*
313  * Function to conditionally start an IO. A read is started immediately,
314  * a write is only started immediately if the flush flag is on or the
315  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
316  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
317  */
318 static inline void
319 raw3215_try_io(struct raw3215_info *raw)
320 {
321 	if (!(raw->flags & RAW3215_ACTIVE))
322 		return;
323 	if (raw->queued_read != NULL)
324 		raw3215_start_io(raw);
325 	else if (raw->queued_write != NULL) {
326 		if ((raw->queued_write->delayable == 0) ||
327 		    (raw->flags & RAW3215_FLUSHING)) {
328 			/* execute write requests bigger than minimum size */
329 			raw3215_start_io(raw);
330 			if (raw->flags & RAW3215_TIMER_RUNS) {
331 				del_timer(&raw->timer);
332 				raw->flags &= ~RAW3215_TIMER_RUNS;
333 			}
334 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
335 			/* delay small writes */
336 			init_timer(&raw->timer);
337 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
338 			raw->timer.data = (unsigned long) raw;
339 			raw->timer.function = raw3215_timeout;
340 			add_timer(&raw->timer);
341 			raw->flags |= RAW3215_TIMER_RUNS;
342 		}
343 	}
344 }
345 
346 /*
347  * The bottom half handler routine for 3215 devices. It tries to start
348  * the next IO and wakes up processes waiting on the tty.
349  */
350 static void
351 raw3215_tasklet(void *data)
352 {
353 	struct raw3215_info *raw;
354 	struct tty_struct *tty;
355 	unsigned long flags;
356 
357 	raw = (struct raw3215_info *) data;
358 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
359 	raw3215_mk_write_req(raw);
360 	raw3215_try_io(raw);
361 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
362 	/* Check for pending message from raw3215_irq */
363 	if (raw->message != NULL) {
364 		printk(raw->message, raw->msg_dstat, raw->msg_cstat);
365 		raw->message = NULL;
366 	}
367 	tty = raw->tty;
368 	if (tty != NULL &&
369 	    RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
370 	    	tty_wakeup(tty);
371 	}
372 }
373 
374 /*
375  * Interrupt routine, called from common io layer
376  */
377 static void
378 raw3215_irq(struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
379 {
380 	struct raw3215_info *raw;
381 	struct raw3215_req *req;
382 	struct tty_struct *tty;
383 	int cstat, dstat;
384 	int count, slen;
385 
386 	raw = cdev->dev.driver_data;
387 	req = (struct raw3215_req *) intparm;
388 	cstat = irb->scsw.cstat;
389 	dstat = irb->scsw.dstat;
390 	if (cstat != 0) {
391 		raw->message = KERN_WARNING
392 			"Got nonzero channel status in raw3215_irq "
393 			"(dev sts 0x%2x, sch sts 0x%2x)";
394 		raw->msg_dstat = dstat;
395 		raw->msg_cstat = cstat;
396 		tasklet_schedule(&raw->tasklet);
397 	}
398 	if (dstat & 0x01) { /* we got a unit exception */
399 		dstat &= ~0x01;	 /* we can ignore it */
400 	}
401 	switch (dstat) {
402 	case 0x80:
403 		if (cstat != 0)
404 			break;
405 		/* Attention interrupt, someone hit the enter key */
406 		raw3215_mk_read_req(raw);
407 		if (MACHINE_IS_P390)
408 			memset(raw->inbuf, 0, RAW3215_INBUF_SIZE);
409 		tasklet_schedule(&raw->tasklet);
410 		break;
411 	case 0x08:
412 	case 0x0C:
413 		/* Channel end interrupt. */
414 		if ((raw = req->info) == NULL)
415 			return;		     /* That shouldn't happen ... */
416 		if (req->type == RAW3215_READ) {
417 			/* store residual count, then wait for device end */
418 			req->residual = irb->scsw.count;
419 		}
420 		if (dstat == 0x08)
421 			break;
422 	case 0x04:
423 		/* Device end interrupt. */
424 		if ((raw = req->info) == NULL)
425 			return;		     /* That shouldn't happen ... */
426 		if (req->type == RAW3215_READ && raw->tty != NULL) {
427 			unsigned int cchar;
428 
429 			tty = raw->tty;
430 			count = 160 - req->residual;
431 			if (MACHINE_IS_P390) {
432 				slen = strnlen(raw->inbuf, RAW3215_INBUF_SIZE);
433 				if (count > slen)
434 					count = slen;
435 			} else
436 			EBCASC(raw->inbuf, count);
437 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
438 			switch (cchar & CTRLCHAR_MASK) {
439 			case CTRLCHAR_SYSRQ:
440 				break;
441 
442 			case CTRLCHAR_CTRL:
443 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
444 				tty_flip_buffer_push(raw->tty);
445 				break;
446 
447 			case CTRLCHAR_NONE:
448 				if (count < 2 ||
449 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
450 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
451 					/* add the auto \n */
452 					raw->inbuf[count] = '\n';
453 					count++;
454 				} else
455 					count -= 2;
456 				tty_insert_flip_string(tty, raw->inbuf, count);
457 				tty_flip_buffer_push(raw->tty);
458 				break;
459 			}
460 		} else if (req->type == RAW3215_WRITE) {
461 			raw->count -= req->len;
462 			raw->written -= req->len;
463 		}
464 		raw->flags &= ~RAW3215_WORKING;
465 		raw3215_free_req(req);
466 		/* check for empty wait */
467 		if (waitqueue_active(&raw->empty_wait) &&
468 		    raw->queued_write == NULL &&
469 		    raw->queued_read == NULL) {
470 			wake_up_interruptible(&raw->empty_wait);
471 		}
472 		tasklet_schedule(&raw->tasklet);
473 		break;
474 	default:
475 		/* Strange interrupt, I'll do my best to clean up */
476 		if (req != NULL && req->type != RAW3215_FREE) {
477 			if (req->type == RAW3215_WRITE) {
478 				raw->count -= req->len;
479 				raw->written -= req->len;
480 			}
481 			raw->flags &= ~RAW3215_WORKING;
482 			raw3215_free_req(req);
483 		}
484 		raw->message = KERN_WARNING
485 			"Spurious interrupt in in raw3215_irq "
486 			"(dev sts 0x%2x, sch sts 0x%2x)";
487 		raw->msg_dstat = dstat;
488 		raw->msg_cstat = cstat;
489 		tasklet_schedule(&raw->tasklet);
490 	}
491 	return;
492 }
493 
494 /*
495  * Wait until length bytes are available int the output buffer.
496  * Has to be called with the s390irq lock held. Can be called
497  * disabled.
498  */
499 static void
500 raw3215_make_room(struct raw3215_info *raw, unsigned int length)
501 {
502 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
503 		/* there might be a request pending */
504 		raw->flags |= RAW3215_FLUSHING;
505 		raw3215_mk_write_req(raw);
506 		raw3215_try_io(raw);
507 		raw->flags &= ~RAW3215_FLUSHING;
508 #ifdef CONFIG_TN3215_CONSOLE
509 		wait_cons_dev();
510 #endif
511 		/* Enough room freed up ? */
512 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
513 			break;
514 		/* there might be another cpu waiting for the lock */
515 		spin_unlock(get_ccwdev_lock(raw->cdev));
516 		udelay(100);
517 		spin_lock(get_ccwdev_lock(raw->cdev));
518 	}
519 }
520 
521 /*
522  * String write routine for 3215 devices
523  */
524 static void
525 raw3215_write(struct raw3215_info *raw, const char *str, unsigned int length)
526 {
527 	unsigned long flags;
528 	int c, count;
529 
530 	while (length > 0) {
531 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
532 		count = (length > RAW3215_BUFFER_SIZE) ?
533 					     RAW3215_BUFFER_SIZE : length;
534 		length -= count;
535 
536 		raw3215_make_room(raw, count);
537 
538 		/* copy string to output buffer and convert it to EBCDIC */
539 		while (1) {
540 			c = min_t(int, count,
541 				  min(RAW3215_BUFFER_SIZE - raw->count,
542 				      RAW3215_BUFFER_SIZE - raw->head));
543 			if (c <= 0)
544 				break;
545 			memcpy(raw->buffer + raw->head, str, c);
546 			ASCEBC(raw->buffer + raw->head, c);
547 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
548 			raw->count += c;
549 			raw->line_pos += c;
550 			str += c;
551 			count -= c;
552 		}
553 		if (!(raw->flags & RAW3215_WORKING)) {
554 			raw3215_mk_write_req(raw);
555 			/* start or queue request */
556 			raw3215_try_io(raw);
557 		}
558 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
559 	}
560 }
561 
562 /*
563  * Put character routine for 3215 devices
564  */
565 static void
566 raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
567 {
568 	unsigned long flags;
569 	unsigned int length, i;
570 
571 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
572 	if (ch == '\t') {
573 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
574 		raw->line_pos += length;
575 		ch = ' ';
576 	} else if (ch == '\n') {
577 		length = 1;
578 		raw->line_pos = 0;
579 	} else {
580 		length = 1;
581 		raw->line_pos++;
582 	}
583 	raw3215_make_room(raw, length);
584 
585 	for (i = 0; i < length; i++) {
586 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
587 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
588 		raw->count++;
589 	}
590 	if (!(raw->flags & RAW3215_WORKING)) {
591 		raw3215_mk_write_req(raw);
592 		/* start or queue request */
593 		raw3215_try_io(raw);
594 	}
595 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
596 }
597 
598 /*
599  * Flush routine, it simply sets the flush flag and tries to start
600  * pending IO.
601  */
602 static void
603 raw3215_flush_buffer(struct raw3215_info *raw)
604 {
605 	unsigned long flags;
606 
607 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
608 	if (raw->count > 0) {
609 		raw->flags |= RAW3215_FLUSHING;
610 		raw3215_try_io(raw);
611 		raw->flags &= ~RAW3215_FLUSHING;
612 	}
613 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
614 }
615 
616 /*
617  * Fire up a 3215 device.
618  */
619 static int
620 raw3215_startup(struct raw3215_info *raw)
621 {
622 	unsigned long flags;
623 
624 	if (raw->flags & RAW3215_ACTIVE)
625 		return 0;
626 	raw->line_pos = 0;
627 	raw->flags |= RAW3215_ACTIVE;
628 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
629 	raw3215_try_io(raw);
630 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
631 
632 	return 0;
633 }
634 
635 /*
636  * Shutdown a 3215 device.
637  */
638 static void
639 raw3215_shutdown(struct raw3215_info *raw)
640 {
641 	DECLARE_WAITQUEUE(wait, current);
642 	unsigned long flags;
643 
644 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FIXED))
645 		return;
646 	/* Wait for outstanding requests, then free irq */
647 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
648 	if ((raw->flags & RAW3215_WORKING) ||
649 	    raw->queued_write != NULL ||
650 	    raw->queued_read != NULL) {
651 		raw->flags |= RAW3215_CLOSING;
652 		add_wait_queue(&raw->empty_wait, &wait);
653 		set_current_state(TASK_INTERRUPTIBLE);
654 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
655 		schedule();
656 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
657 		remove_wait_queue(&raw->empty_wait, &wait);
658 		set_current_state(TASK_RUNNING);
659 		raw->flags &= ~(RAW3215_ACTIVE | RAW3215_CLOSING);
660 	}
661 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
662 }
663 
664 static int
665 raw3215_probe (struct ccw_device *cdev)
666 {
667 	struct raw3215_info *raw;
668 	int line;
669 
670 	raw = kmalloc(sizeof(struct raw3215_info) +
671 		      RAW3215_INBUF_SIZE, GFP_KERNEL|GFP_DMA);
672 	if (raw == NULL)
673 		return -ENOMEM;
674 
675 	spin_lock(&raw3215_device_lock);
676 	for (line = 0; line < NR_3215; line++) {
677 		if (!raw3215[line]) {
678 			raw3215[line] = raw;
679 			break;
680 		}
681 	}
682 	spin_unlock(&raw3215_device_lock);
683 	if (line == NR_3215) {
684 		kfree(raw);
685 		return -ENODEV;
686 	}
687 
688 	raw->cdev = cdev;
689 	raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
690 	memset(raw, 0, sizeof(struct raw3215_info));
691 	raw->buffer = kmalloc(RAW3215_BUFFER_SIZE,
692 				       GFP_KERNEL|GFP_DMA);
693 	if (raw->buffer == NULL) {
694 		spin_lock(&raw3215_device_lock);
695 		raw3215[line] = NULL;
696 		spin_unlock(&raw3215_device_lock);
697 		kfree(raw);
698 		return -ENOMEM;
699 	}
700 	tasklet_init(&raw->tasklet,
701 		     (void (*)(unsigned long)) raw3215_tasklet,
702 		     (unsigned long) raw);
703 	init_waitqueue_head(&raw->empty_wait);
704 
705 	cdev->dev.driver_data = raw;
706 	cdev->handler = raw3215_irq;
707 
708 	return 0;
709 }
710 
711 static void
712 raw3215_remove (struct ccw_device *cdev)
713 {
714 	struct raw3215_info *raw;
715 
716 	ccw_device_set_offline(cdev);
717 	raw = cdev->dev.driver_data;
718 	if (raw) {
719 		cdev->dev.driver_data = NULL;
720 		kfree(raw->buffer);
721 		kfree(raw);
722 	}
723 }
724 
725 static int
726 raw3215_set_online (struct ccw_device *cdev)
727 {
728 	struct raw3215_info *raw;
729 
730 	raw = cdev->dev.driver_data;
731 	if (!raw)
732 		return -ENODEV;
733 
734 	return raw3215_startup(raw);
735 }
736 
737 static int
738 raw3215_set_offline (struct ccw_device *cdev)
739 {
740 	struct raw3215_info *raw;
741 
742 	raw = cdev->dev.driver_data;
743 	if (!raw)
744 		return -ENODEV;
745 
746 	raw3215_shutdown(raw);
747 
748 	return 0;
749 }
750 
751 static struct ccw_device_id raw3215_id[] = {
752 	{ CCW_DEVICE(0x3215, 0) },
753 	{ /* end of list */ },
754 };
755 
756 static struct ccw_driver raw3215_ccw_driver = {
757 	.name		= "3215",
758 	.owner		= THIS_MODULE,
759 	.ids		= raw3215_id,
760 	.probe		= &raw3215_probe,
761 	.remove		= &raw3215_remove,
762 	.set_online	= &raw3215_set_online,
763 	.set_offline	= &raw3215_set_offline,
764 };
765 
766 #ifdef CONFIG_TN3215_CONSOLE
767 /*
768  * Write a string to the 3215 console
769  */
770 static void
771 con3215_write(struct console *co, const char *str, unsigned int count)
772 {
773 	struct raw3215_info *raw;
774 	int i;
775 
776 	if (count <= 0)
777 		return;
778 	raw = raw3215[0];	/* console 3215 is the first one */
779 	while (count > 0) {
780 		for (i = 0; i < count; i++)
781 			if (str[i] == '\t' || str[i] == '\n')
782 				break;
783 		raw3215_write(raw, str, i);
784 		count -= i;
785 		str += i;
786 		if (count > 0) {
787 			raw3215_putchar(raw, *str);
788 			count--;
789 			str++;
790 		}
791 	}
792 }
793 
794 static struct tty_driver *con3215_device(struct console *c, int *index)
795 {
796 	*index = c->index;
797 	return tty3215_driver;
798 }
799 
800 /*
801  * panic() calls console_unblank before the system enters a
802  * disabled, endless loop.
803  */
804 static void
805 con3215_unblank(void)
806 {
807 	struct raw3215_info *raw;
808 	unsigned long flags;
809 
810 	raw = raw3215[0];  /* console 3215 is the first one */
811 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
812 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
813 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
814 }
815 
816 /*
817  *  The console structure for the 3215 console
818  */
819 static struct console con3215 = {
820 	.name	 = "ttyS",
821 	.write	 = con3215_write,
822 	.device	 = con3215_device,
823 	.unblank = con3215_unblank,
824 	.flags	 = CON_PRINTBUFFER,
825 };
826 
827 /*
828  * 3215 console initialization code called from console_init().
829  * NOTE: This is called before kmalloc is available.
830  */
831 static int __init
832 con3215_init(void)
833 {
834 	struct ccw_device *cdev;
835 	struct raw3215_info *raw;
836 	struct raw3215_req *req;
837 	int i;
838 
839 	/* Check if 3215 is to be the console */
840 	if (!CONSOLE_IS_3215)
841 		return -ENODEV;
842 
843 	/* Set the console mode for VM */
844 	if (MACHINE_IS_VM) {
845 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
846 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
847 	}
848 
849 	/* allocate 3215 request structures */
850 	raw3215_freelist = NULL;
851 	spin_lock_init(&raw3215_freelist_lock);
852 	for (i = 0; i < NR_3215_REQ; i++) {
853 		req = (struct raw3215_req *) alloc_bootmem_low(sizeof(struct raw3215_req));
854 		req->next = raw3215_freelist;
855 		raw3215_freelist = req;
856 	}
857 
858 	cdev = ccw_device_probe_console();
859 	if (IS_ERR(cdev))
860 		return -ENODEV;
861 
862 	raw3215[0] = raw = (struct raw3215_info *)
863 		alloc_bootmem_low(sizeof(struct raw3215_info));
864 	memset(raw, 0, sizeof(struct raw3215_info));
865 	raw->buffer = (char *) alloc_bootmem_low(RAW3215_BUFFER_SIZE);
866 	raw->inbuf = (char *) alloc_bootmem_low(RAW3215_INBUF_SIZE);
867 	raw->cdev = cdev;
868 	cdev->dev.driver_data = raw;
869 	cdev->handler = raw3215_irq;
870 
871 	raw->flags |= RAW3215_FIXED;
872 	tasklet_init(&raw->tasklet,
873 		     (void (*)(unsigned long)) raw3215_tasklet,
874 		     (unsigned long) raw);
875 	init_waitqueue_head(&raw->empty_wait);
876 
877 	/* Request the console irq */
878 	if (raw3215_startup(raw) != 0) {
879 		free_bootmem((unsigned long) raw->inbuf, RAW3215_INBUF_SIZE);
880 		free_bootmem((unsigned long) raw->buffer, RAW3215_BUFFER_SIZE);
881 		free_bootmem((unsigned long) raw, sizeof(struct raw3215_info));
882 		raw3215[0] = NULL;
883 		printk("Couldn't find a 3215 console device\n");
884 		return -ENODEV;
885 	}
886 	register_console(&con3215);
887 	return 0;
888 }
889 console_initcall(con3215_init);
890 #endif
891 
892 /*
893  * tty3215_open
894  *
895  * This routine is called whenever a 3215 tty is opened.
896  */
897 static int
898 tty3215_open(struct tty_struct *tty, struct file * filp)
899 {
900 	struct raw3215_info *raw;
901 	int retval, line;
902 
903 	line = tty->index;
904 	if ((line < 0) || (line >= NR_3215))
905 		return -ENODEV;
906 
907 	raw = raw3215[line];
908 	if (raw == NULL)
909 		return -ENODEV;
910 
911 	tty->driver_data = raw;
912 	raw->tty = tty;
913 
914 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
915 	/*
916 	 * Start up 3215 device
917 	 */
918 	retval = raw3215_startup(raw);
919 	if (retval)
920 		return retval;
921 
922 	return 0;
923 }
924 
925 /*
926  * tty3215_close()
927  *
928  * This routine is called when the 3215 tty is closed. We wait
929  * for the remaining request to be completed. Then we clean up.
930  */
931 static void
932 tty3215_close(struct tty_struct *tty, struct file * filp)
933 {
934 	struct raw3215_info *raw;
935 
936 	raw = (struct raw3215_info *) tty->driver_data;
937 	if (raw == NULL || tty->count > 1)
938 		return;
939 	tty->closing = 1;
940 	/* Shutdown the terminal */
941 	raw3215_shutdown(raw);
942 	tty->closing = 0;
943 	raw->tty = NULL;
944 }
945 
946 /*
947  * Returns the amount of free space in the output buffer.
948  */
949 static int
950 tty3215_write_room(struct tty_struct *tty)
951 {
952 	struct raw3215_info *raw;
953 
954 	raw = (struct raw3215_info *) tty->driver_data;
955 
956 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
957 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
958 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
959 	else
960 		return 0;
961 }
962 
963 /*
964  * String write routine for 3215 ttys
965  */
966 static int
967 tty3215_write(struct tty_struct * tty,
968 	      const unsigned char *buf, int count)
969 {
970 	struct raw3215_info *raw;
971 
972 	if (!tty)
973 		return 0;
974 	raw = (struct raw3215_info *) tty->driver_data;
975 	raw3215_write(raw, buf, count);
976 	return count;
977 }
978 
979 /*
980  * Put character routine for 3215 ttys
981  */
982 static void
983 tty3215_put_char(struct tty_struct *tty, unsigned char ch)
984 {
985 	struct raw3215_info *raw;
986 
987 	if (!tty)
988 		return;
989 	raw = (struct raw3215_info *) tty->driver_data;
990 	raw3215_putchar(raw, ch);
991 }
992 
993 static void
994 tty3215_flush_chars(struct tty_struct *tty)
995 {
996 }
997 
998 /*
999  * Returns the number of characters in the output buffer
1000  */
1001 static int
1002 tty3215_chars_in_buffer(struct tty_struct *tty)
1003 {
1004 	struct raw3215_info *raw;
1005 
1006 	raw = (struct raw3215_info *) tty->driver_data;
1007 	return raw->count;
1008 }
1009 
1010 static void
1011 tty3215_flush_buffer(struct tty_struct *tty)
1012 {
1013 	struct raw3215_info *raw;
1014 
1015 	raw = (struct raw3215_info *) tty->driver_data;
1016 	raw3215_flush_buffer(raw);
1017 	tty_wakeup(tty);
1018 }
1019 
1020 /*
1021  * Currently we don't have any io controls for 3215 ttys
1022  */
1023 static int
1024 tty3215_ioctl(struct tty_struct *tty, struct file * file,
1025 	      unsigned int cmd, unsigned long arg)
1026 {
1027 	if (tty->flags & (1 << TTY_IO_ERROR))
1028 		return -EIO;
1029 
1030 	switch (cmd) {
1031 	default:
1032 		return -ENOIOCTLCMD;
1033 	}
1034 	return 0;
1035 }
1036 
1037 /*
1038  * Disable reading from a 3215 tty
1039  */
1040 static void
1041 tty3215_throttle(struct tty_struct * tty)
1042 {
1043 	struct raw3215_info *raw;
1044 
1045 	raw = (struct raw3215_info *) tty->driver_data;
1046 	raw->flags |= RAW3215_THROTTLED;
1047 }
1048 
1049 /*
1050  * Enable reading from a 3215 tty
1051  */
1052 static void
1053 tty3215_unthrottle(struct tty_struct * tty)
1054 {
1055 	struct raw3215_info *raw;
1056 	unsigned long flags;
1057 
1058 	raw = (struct raw3215_info *) tty->driver_data;
1059 	if (raw->flags & RAW3215_THROTTLED) {
1060 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1061 		raw->flags &= ~RAW3215_THROTTLED;
1062 		raw3215_try_io(raw);
1063 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1064 	}
1065 }
1066 
1067 /*
1068  * Disable writing to a 3215 tty
1069  */
1070 static void
1071 tty3215_stop(struct tty_struct *tty)
1072 {
1073 	struct raw3215_info *raw;
1074 
1075 	raw = (struct raw3215_info *) tty->driver_data;
1076 	raw->flags |= RAW3215_STOPPED;
1077 }
1078 
1079 /*
1080  * Enable writing to a 3215 tty
1081  */
1082 static void
1083 tty3215_start(struct tty_struct *tty)
1084 {
1085 	struct raw3215_info *raw;
1086 	unsigned long flags;
1087 
1088 	raw = (struct raw3215_info *) tty->driver_data;
1089 	if (raw->flags & RAW3215_STOPPED) {
1090 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1091 		raw->flags &= ~RAW3215_STOPPED;
1092 		raw3215_try_io(raw);
1093 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1094 	}
1095 }
1096 
1097 static const struct tty_operations tty3215_ops = {
1098 	.open = tty3215_open,
1099 	.close = tty3215_close,
1100 	.write = tty3215_write,
1101 	.put_char = tty3215_put_char,
1102 	.flush_chars = tty3215_flush_chars,
1103 	.write_room = tty3215_write_room,
1104 	.chars_in_buffer = tty3215_chars_in_buffer,
1105 	.flush_buffer = tty3215_flush_buffer,
1106 	.ioctl = tty3215_ioctl,
1107 	.throttle = tty3215_throttle,
1108 	.unthrottle = tty3215_unthrottle,
1109 	.stop = tty3215_stop,
1110 	.start = tty3215_start,
1111 };
1112 
1113 /*
1114  * 3215 tty registration code called from tty_init().
1115  * Most kernel services (incl. kmalloc) are available at this poimt.
1116  */
1117 static int __init
1118 tty3215_init(void)
1119 {
1120 	struct tty_driver *driver;
1121 	int ret;
1122 
1123 	if (!CONSOLE_IS_3215)
1124 		return 0;
1125 
1126 	driver = alloc_tty_driver(NR_3215);
1127 	if (!driver)
1128 		return -ENOMEM;
1129 
1130 	ret = ccw_driver_register(&raw3215_ccw_driver);
1131 	if (ret) {
1132 		put_tty_driver(driver);
1133 		return ret;
1134 	}
1135 	/*
1136 	 * Initialize the tty_driver structure
1137 	 * Entries in tty3215_driver that are NOT initialized:
1138 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1139 	 */
1140 
1141 	driver->owner = THIS_MODULE;
1142 	driver->driver_name = "tty3215";
1143 	driver->name = "ttyS";
1144 	driver->major = TTY_MAJOR;
1145 	driver->minor_start = 64;
1146 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1147 	driver->subtype = SYSTEM_TYPE_TTY;
1148 	driver->init_termios = tty_std_termios;
1149 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1150 	driver->init_termios.c_oflag = ONLCR | XTABS;
1151 	driver->init_termios.c_lflag = ISIG;
1152 	driver->flags = TTY_DRIVER_REAL_RAW;
1153 	tty_set_operations(driver, &tty3215_ops);
1154 	ret = tty_register_driver(driver);
1155 	if (ret) {
1156 		printk("Couldn't register tty3215 driver\n");
1157 		put_tty_driver(driver);
1158 		return ret;
1159 	}
1160 	tty3215_driver = driver;
1161 	return 0;
1162 }
1163 
1164 static void __exit
1165 tty3215_exit(void)
1166 {
1167 	tty_unregister_driver(tty3215_driver);
1168 	put_tty_driver(tty3215_driver);
1169 	ccw_driver_unregister(&raw3215_ccw_driver);
1170 }
1171 
1172 module_init(tty3215_init);
1173 module_exit(tty3215_exit);
1174