xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 54525552)
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/kernel_stat.h>
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/kdev_t.h>
16 #include <linux/tty.h>
17 #include <linux/tty_flip.h>
18 #include <linux/vt_kern.h>
19 #include <linux/init.h>
20 #include <linux/console.h>
21 #include <linux/interrupt.h>
22 #include <linux/err.h>
23 #include <linux/reboot.h>
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_ACTIVE	    2	      /* set if the device is in use */
49 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
50 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
51 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
52 #define RAW3215_CLOSING	    32	      /* set while in close process */
53 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
54 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
55 #define RAW3215_FROZEN	    256	      /* set if 3215 is frozen for suspend */
56 
57 #define TAB_STOP_SIZE	    8	      /* tab stop size */
58 
59 /*
60  * Request types for a 3215 device
61  */
62 enum raw3215_type {
63 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
64 };
65 
66 /*
67  * Request structure for a 3215 device
68  */
69 struct raw3215_req {
70 	enum raw3215_type type;	      /* type of the request */
71 	int start, len;		      /* start index & len in output buffer */
72 	int delayable;		      /* indication to wait for more data */
73 	int residual;		      /* residual count for read request */
74 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
75 	struct raw3215_info *info;    /* pointer to main structure */
76 	struct raw3215_req *next;     /* pointer to next request */
77 } __attribute__ ((aligned(8)));
78 
79 struct raw3215_info {
80 	struct ccw_device *cdev;      /* device for tty driver */
81 	spinlock_t *lock;	      /* pointer to irq lock */
82 	int flags;		      /* state flags */
83 	char *buffer;		      /* pointer to output buffer */
84 	char *inbuf;		      /* pointer to input buffer */
85 	int head;		      /* first free byte in output buffer */
86 	int count;		      /* number of bytes in output buffer */
87 	int written;		      /* number of bytes in write requests */
88 	struct tty_struct *tty;	      /* pointer to tty structure if present */
89 	struct raw3215_req *queued_read; /* pointer to queued read requests */
90 	struct raw3215_req *queued_write;/* pointer to queued write requests */
91 	wait_queue_head_t empty_wait; /* wait queue for flushing */
92 	struct timer_list timer;      /* timer for delayed output */
93 	int line_pos;		      /* position on the line (for tabs) */
94 	char ubuffer[80];	      /* copy_from_user buffer */
95 };
96 
97 /* array of 3215 devices structures */
98 static struct raw3215_info *raw3215[NR_3215];
99 /* spinlock to protect the raw3215 array */
100 static DEFINE_SPINLOCK(raw3215_device_lock);
101 /* list of free request structures */
102 static struct raw3215_req *raw3215_freelist;
103 /* spinlock to protect free list */
104 static spinlock_t raw3215_freelist_lock;
105 
106 static struct tty_driver *tty3215_driver;
107 
108 /*
109  * Get a request structure from the free list
110  */
111 static inline struct raw3215_req *raw3215_alloc_req(void)
112 {
113 	struct raw3215_req *req;
114 	unsigned long flags;
115 
116 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
117 	req = raw3215_freelist;
118 	raw3215_freelist = req->next;
119 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
120 	return req;
121 }
122 
123 /*
124  * Put a request structure back to the free list
125  */
126 static inline void raw3215_free_req(struct raw3215_req *req)
127 {
128 	unsigned long flags;
129 
130 	if (req->type == RAW3215_FREE)
131 		return;		/* don't free a free request */
132 	req->type = RAW3215_FREE;
133 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
134 	req->next = raw3215_freelist;
135 	raw3215_freelist = req;
136 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
137 }
138 
139 /*
140  * Set up a read request that reads up to 160 byte from the 3215 device.
141  * If there is a queued read request it is used, but that shouldn't happen
142  * because a 3215 terminal won't accept a new read before the old one is
143  * completed.
144  */
145 static void raw3215_mk_read_req(struct raw3215_info *raw)
146 {
147 	struct raw3215_req *req;
148 	struct ccw1 *ccw;
149 
150 	/* there can only be ONE read request at a time */
151 	req = raw->queued_read;
152 	if (req == NULL) {
153 		/* no queued read request, use new req structure */
154 		req = raw3215_alloc_req();
155 		req->type = RAW3215_READ;
156 		req->info = raw;
157 		raw->queued_read = req;
158 	}
159 
160 	ccw = req->ccws;
161 	ccw->cmd_code = 0x0A; /* read inquiry */
162 	ccw->flags = 0x20;    /* ignore incorrect length */
163 	ccw->count = 160;
164 	ccw->cda = (__u32) __pa(raw->inbuf);
165 }
166 
167 /*
168  * Set up a write request with the information from the main structure.
169  * A ccw chain is created that writes as much as possible from the output
170  * buffer to the 3215 device. If a queued write exists it is replaced by
171  * the new, probably lengthened request.
172  */
173 static void raw3215_mk_write_req(struct raw3215_info *raw)
174 {
175 	struct raw3215_req *req;
176 	struct ccw1 *ccw;
177 	int len, count, ix, lines;
178 
179 	if (raw->count <= raw->written)
180 		return;
181 	/* check if there is a queued write request */
182 	req = raw->queued_write;
183 	if (req == NULL) {
184 		/* no queued write request, use new req structure */
185 		req = raw3215_alloc_req();
186 		req->type = RAW3215_WRITE;
187 		req->info = raw;
188 		raw->queued_write = req;
189 	} else {
190 		raw->written -= req->len;
191 	}
192 
193 	ccw = req->ccws;
194 	req->start = (raw->head - raw->count + raw->written) &
195 		     (RAW3215_BUFFER_SIZE - 1);
196 	/*
197 	 * now we have to count newlines. We can at max accept
198 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
199 	 * a restriction in VM
200 	 */
201 	lines = 0;
202 	ix = req->start;
203 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
204 		if (raw->buffer[ix] == 0x15)
205 			lines++;
206 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
207 	}
208 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
209 	if (len > RAW3215_MAX_BYTES)
210 		len = RAW3215_MAX_BYTES;
211 	req->len = len;
212 	raw->written += len;
213 
214 	/* set the indication if we should try to enlarge this request */
215 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
216 
217 	ix = req->start;
218 	while (len > 0) {
219 		if (ccw > req->ccws)
220 			ccw[-1].flags |= 0x40; /* use command chaining */
221 		ccw->cmd_code = 0x01; /* write, auto carrier return */
222 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
223 		ccw->cda =
224 			(__u32) __pa(raw->buffer + ix);
225 		count = len;
226 		if (ix + count > RAW3215_BUFFER_SIZE)
227 			count = RAW3215_BUFFER_SIZE - ix;
228 		ccw->count = count;
229 		len -= count;
230 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
231 		ccw++;
232 	}
233 	/*
234 	 * Add a NOP to the channel program. 3215 devices are purely
235 	 * emulated and its much better to avoid the channel end
236 	 * interrupt in this case.
237 	 */
238 	if (ccw > req->ccws)
239 		ccw[-1].flags |= 0x40; /* use command chaining */
240 	ccw->cmd_code = 0x03; /* NOP */
241 	ccw->flags = 0;
242 	ccw->cda = 0;
243 	ccw->count = 1;
244 }
245 
246 /*
247  * Start a read or a write request
248  */
249 static void raw3215_start_io(struct raw3215_info *raw)
250 {
251 	struct raw3215_req *req;
252 	int res;
253 
254 	req = raw->queued_read;
255 	if (req != NULL &&
256 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
257 		/* dequeue request */
258 		raw->queued_read = NULL;
259 		res = ccw_device_start(raw->cdev, req->ccws,
260 				       (unsigned long) req, 0, 0);
261 		if (res != 0) {
262 			/* do_IO failed, put request back to queue */
263 			raw->queued_read = req;
264 		} else {
265 			raw->flags |= RAW3215_WORKING;
266 		}
267 	}
268 	req = raw->queued_write;
269 	if (req != NULL &&
270 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
271 		/* dequeue request */
272 		raw->queued_write = NULL;
273 		res = ccw_device_start(raw->cdev, req->ccws,
274 				       (unsigned long) req, 0, 0);
275 		if (res != 0) {
276 			/* do_IO failed, put request back to queue */
277 			raw->queued_write = req;
278 		} else {
279 			raw->flags |= RAW3215_WORKING;
280 		}
281 	}
282 }
283 
284 /*
285  * Function to start a delayed output after RAW3215_TIMEOUT seconds
286  */
287 static void raw3215_timeout(unsigned long __data)
288 {
289 	struct raw3215_info *raw = (struct raw3215_info *) __data;
290 	unsigned long flags;
291 
292 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
293 	if (raw->flags & RAW3215_TIMER_RUNS) {
294 		del_timer(&raw->timer);
295 		raw->flags &= ~RAW3215_TIMER_RUNS;
296 		if (!(raw->flags & RAW3215_FROZEN)) {
297 			raw3215_mk_write_req(raw);
298 			raw3215_start_io(raw);
299 		}
300 	}
301 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
302 }
303 
304 /*
305  * Function to conditionally start an IO. A read is started immediately,
306  * a write is only started immediately if the flush flag is on or the
307  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
308  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
309  */
310 static inline void raw3215_try_io(struct raw3215_info *raw)
311 {
312 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FROZEN))
313 		return;
314 	if (raw->queued_read != NULL)
315 		raw3215_start_io(raw);
316 	else if (raw->queued_write != NULL) {
317 		if ((raw->queued_write->delayable == 0) ||
318 		    (raw->flags & RAW3215_FLUSHING)) {
319 			/* execute write requests bigger than minimum size */
320 			raw3215_start_io(raw);
321 			if (raw->flags & RAW3215_TIMER_RUNS) {
322 				del_timer(&raw->timer);
323 				raw->flags &= ~RAW3215_TIMER_RUNS;
324 			}
325 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
326 			/* delay small writes */
327 			init_timer(&raw->timer);
328 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
329 			raw->timer.data = (unsigned long) raw;
330 			raw->timer.function = raw3215_timeout;
331 			add_timer(&raw->timer);
332 			raw->flags |= RAW3215_TIMER_RUNS;
333 		}
334 	}
335 }
336 
337 /*
338  * Try to start the next IO and wake up processes waiting on the tty.
339  */
340 static void raw3215_next_io(struct raw3215_info *raw)
341 {
342 	struct tty_struct *tty;
343 
344 	raw3215_mk_write_req(raw);
345 	raw3215_try_io(raw);
346 	tty = raw->tty;
347 	if (tty != NULL &&
348 	    RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
349 	    	tty_wakeup(tty);
350 	}
351 }
352 
353 /*
354  * Interrupt routine, called from common io layer
355  */
356 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
357 			struct irb *irb)
358 {
359 	struct raw3215_info *raw;
360 	struct raw3215_req *req;
361 	struct tty_struct *tty;
362 	int cstat, dstat;
363 	int count;
364 
365 	kstat_cpu(smp_processor_id()).irqs[IOINT_C15]++;
366 	raw = dev_get_drvdata(&cdev->dev);
367 	req = (struct raw3215_req *) intparm;
368 	cstat = irb->scsw.cmd.cstat;
369 	dstat = irb->scsw.cmd.dstat;
370 	if (cstat != 0)
371 		raw3215_next_io(raw);
372 	if (dstat & 0x01) { /* we got a unit exception */
373 		dstat &= ~0x01;	 /* we can ignore it */
374 	}
375 	switch (dstat) {
376 	case 0x80:
377 		if (cstat != 0)
378 			break;
379 		/* Attention interrupt, someone hit the enter key */
380 		raw3215_mk_read_req(raw);
381 		raw3215_next_io(raw);
382 		break;
383 	case 0x08:
384 	case 0x0C:
385 		/* Channel end interrupt. */
386 		if ((raw = req->info) == NULL)
387 			return;		     /* That shouldn't happen ... */
388 		if (req->type == RAW3215_READ) {
389 			/* store residual count, then wait for device end */
390 			req->residual = irb->scsw.cmd.count;
391 		}
392 		if (dstat == 0x08)
393 			break;
394 	case 0x04:
395 		/* Device end interrupt. */
396 		if ((raw = req->info) == NULL)
397 			return;		     /* That shouldn't happen ... */
398 		if (req->type == RAW3215_READ && raw->tty != NULL) {
399 			unsigned int cchar;
400 
401 			tty = raw->tty;
402 			count = 160 - req->residual;
403 			EBCASC(raw->inbuf, count);
404 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
405 			switch (cchar & CTRLCHAR_MASK) {
406 			case CTRLCHAR_SYSRQ:
407 				break;
408 
409 			case CTRLCHAR_CTRL:
410 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
411 				tty_flip_buffer_push(raw->tty);
412 				break;
413 
414 			case CTRLCHAR_NONE:
415 				if (count < 2 ||
416 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
417 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
418 					/* add the auto \n */
419 					raw->inbuf[count] = '\n';
420 					count++;
421 				} else
422 					count -= 2;
423 				tty_insert_flip_string(tty, raw->inbuf, count);
424 				tty_flip_buffer_push(raw->tty);
425 				break;
426 			}
427 		} else if (req->type == RAW3215_WRITE) {
428 			raw->count -= req->len;
429 			raw->written -= req->len;
430 		}
431 		raw->flags &= ~RAW3215_WORKING;
432 		raw3215_free_req(req);
433 		/* check for empty wait */
434 		if (waitqueue_active(&raw->empty_wait) &&
435 		    raw->queued_write == NULL &&
436 		    raw->queued_read == NULL) {
437 			wake_up_interruptible(&raw->empty_wait);
438 		}
439 		raw3215_next_io(raw);
440 		break;
441 	default:
442 		/* Strange interrupt, I'll do my best to clean up */
443 		if (req != NULL && req->type != RAW3215_FREE) {
444 			if (req->type == RAW3215_WRITE) {
445 				raw->count -= req->len;
446 				raw->written -= req->len;
447 			}
448 			raw->flags &= ~RAW3215_WORKING;
449 			raw3215_free_req(req);
450 		}
451 		raw3215_next_io(raw);
452 	}
453 	return;
454 }
455 
456 /*
457  * Drop the oldest line from the output buffer.
458  */
459 static void raw3215_drop_line(struct raw3215_info *raw)
460 {
461 	int ix;
462 	char ch;
463 
464 	BUG_ON(raw->written != 0);
465 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
466 	while (raw->count > 0) {
467 		ch = raw->buffer[ix];
468 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
469 		raw->count--;
470 		if (ch == 0x15)
471 			break;
472 	}
473 	raw->head = ix;
474 }
475 
476 /*
477  * Wait until length bytes are available int the output buffer.
478  * Has to be called with the s390irq lock held. Can be called
479  * disabled.
480  */
481 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
482 {
483 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
484 		/* While console is frozen for suspend we have no other
485 		 * choice but to drop message from the buffer to make
486 		 * room for even more messages. */
487 		if (raw->flags & RAW3215_FROZEN) {
488 			raw3215_drop_line(raw);
489 			continue;
490 		}
491 		/* there might be a request pending */
492 		raw->flags |= RAW3215_FLUSHING;
493 		raw3215_mk_write_req(raw);
494 		raw3215_try_io(raw);
495 		raw->flags &= ~RAW3215_FLUSHING;
496 #ifdef CONFIG_TN3215_CONSOLE
497 		wait_cons_dev();
498 #endif
499 		/* Enough room freed up ? */
500 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
501 			break;
502 		/* there might be another cpu waiting for the lock */
503 		spin_unlock(get_ccwdev_lock(raw->cdev));
504 		udelay(100);
505 		spin_lock(get_ccwdev_lock(raw->cdev));
506 	}
507 }
508 
509 /*
510  * String write routine for 3215 devices
511  */
512 static void raw3215_write(struct raw3215_info *raw, const char *str,
513 			  unsigned int length)
514 {
515 	unsigned long flags;
516 	int c, count;
517 
518 	while (length > 0) {
519 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
520 		count = (length > RAW3215_BUFFER_SIZE) ?
521 					     RAW3215_BUFFER_SIZE : length;
522 		length -= count;
523 
524 		raw3215_make_room(raw, count);
525 
526 		/* copy string to output buffer and convert it to EBCDIC */
527 		while (1) {
528 			c = min_t(int, count,
529 				  min(RAW3215_BUFFER_SIZE - raw->count,
530 				      RAW3215_BUFFER_SIZE - raw->head));
531 			if (c <= 0)
532 				break;
533 			memcpy(raw->buffer + raw->head, str, c);
534 			ASCEBC(raw->buffer + raw->head, c);
535 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
536 			raw->count += c;
537 			raw->line_pos += c;
538 			str += c;
539 			count -= c;
540 		}
541 		if (!(raw->flags & RAW3215_WORKING)) {
542 			raw3215_mk_write_req(raw);
543 			/* start or queue request */
544 			raw3215_try_io(raw);
545 		}
546 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
547 	}
548 }
549 
550 /*
551  * Put character routine for 3215 devices
552  */
553 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
554 {
555 	unsigned long flags;
556 	unsigned int length, i;
557 
558 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
559 	if (ch == '\t') {
560 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
561 		raw->line_pos += length;
562 		ch = ' ';
563 	} else if (ch == '\n') {
564 		length = 1;
565 		raw->line_pos = 0;
566 	} else {
567 		length = 1;
568 		raw->line_pos++;
569 	}
570 	raw3215_make_room(raw, length);
571 
572 	for (i = 0; i < length; i++) {
573 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
574 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
575 		raw->count++;
576 	}
577 	if (!(raw->flags & RAW3215_WORKING)) {
578 		raw3215_mk_write_req(raw);
579 		/* start or queue request */
580 		raw3215_try_io(raw);
581 	}
582 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
583 }
584 
585 /*
586  * Flush routine, it simply sets the flush flag and tries to start
587  * pending IO.
588  */
589 static void raw3215_flush_buffer(struct raw3215_info *raw)
590 {
591 	unsigned long flags;
592 
593 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
594 	if (raw->count > 0) {
595 		raw->flags |= RAW3215_FLUSHING;
596 		raw3215_try_io(raw);
597 		raw->flags &= ~RAW3215_FLUSHING;
598 	}
599 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
600 }
601 
602 /*
603  * Fire up a 3215 device.
604  */
605 static int raw3215_startup(struct raw3215_info *raw)
606 {
607 	unsigned long flags;
608 
609 	if (raw->flags & RAW3215_ACTIVE)
610 		return 0;
611 	raw->line_pos = 0;
612 	raw->flags |= RAW3215_ACTIVE;
613 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
614 	raw3215_try_io(raw);
615 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
616 
617 	return 0;
618 }
619 
620 /*
621  * Shutdown a 3215 device.
622  */
623 static void raw3215_shutdown(struct raw3215_info *raw)
624 {
625 	DECLARE_WAITQUEUE(wait, current);
626 	unsigned long flags;
627 
628 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FIXED))
629 		return;
630 	/* Wait for outstanding requests, then free irq */
631 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
632 	if ((raw->flags & RAW3215_WORKING) ||
633 	    raw->queued_write != NULL ||
634 	    raw->queued_read != NULL) {
635 		raw->flags |= RAW3215_CLOSING;
636 		add_wait_queue(&raw->empty_wait, &wait);
637 		set_current_state(TASK_INTERRUPTIBLE);
638 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
639 		schedule();
640 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
641 		remove_wait_queue(&raw->empty_wait, &wait);
642 		set_current_state(TASK_RUNNING);
643 		raw->flags &= ~(RAW3215_ACTIVE | RAW3215_CLOSING);
644 	}
645 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
646 }
647 
648 static int raw3215_probe (struct ccw_device *cdev)
649 {
650 	struct raw3215_info *raw;
651 	int line;
652 
653 	/* Console is special. */
654 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
655 		return 0;
656 	raw = kmalloc(sizeof(struct raw3215_info) +
657 		      RAW3215_INBUF_SIZE, GFP_KERNEL|GFP_DMA);
658 	if (raw == NULL)
659 		return -ENOMEM;
660 
661 	spin_lock(&raw3215_device_lock);
662 	for (line = 0; line < NR_3215; line++) {
663 		if (!raw3215[line]) {
664 			raw3215[line] = raw;
665 			break;
666 		}
667 	}
668 	spin_unlock(&raw3215_device_lock);
669 	if (line == NR_3215) {
670 		kfree(raw);
671 		return -ENODEV;
672 	}
673 
674 	raw->cdev = cdev;
675 	raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
676 	memset(raw, 0, sizeof(struct raw3215_info));
677 	raw->buffer = kmalloc(RAW3215_BUFFER_SIZE,
678 				       GFP_KERNEL|GFP_DMA);
679 	if (raw->buffer == NULL) {
680 		spin_lock(&raw3215_device_lock);
681 		raw3215[line] = NULL;
682 		spin_unlock(&raw3215_device_lock);
683 		kfree(raw);
684 		return -ENOMEM;
685 	}
686 	init_waitqueue_head(&raw->empty_wait);
687 
688 	dev_set_drvdata(&cdev->dev, raw);
689 	cdev->handler = raw3215_irq;
690 
691 	return 0;
692 }
693 
694 static void raw3215_remove (struct ccw_device *cdev)
695 {
696 	struct raw3215_info *raw;
697 
698 	ccw_device_set_offline(cdev);
699 	raw = dev_get_drvdata(&cdev->dev);
700 	if (raw) {
701 		dev_set_drvdata(&cdev->dev, NULL);
702 		kfree(raw->buffer);
703 		kfree(raw);
704 	}
705 }
706 
707 static int raw3215_set_online (struct ccw_device *cdev)
708 {
709 	struct raw3215_info *raw;
710 
711 	raw = dev_get_drvdata(&cdev->dev);
712 	if (!raw)
713 		return -ENODEV;
714 
715 	return raw3215_startup(raw);
716 }
717 
718 static int raw3215_set_offline (struct ccw_device *cdev)
719 {
720 	struct raw3215_info *raw;
721 
722 	raw = dev_get_drvdata(&cdev->dev);
723 	if (!raw)
724 		return -ENODEV;
725 
726 	raw3215_shutdown(raw);
727 
728 	return 0;
729 }
730 
731 static int raw3215_pm_stop(struct ccw_device *cdev)
732 {
733 	struct raw3215_info *raw;
734 	unsigned long flags;
735 
736 	/* Empty the output buffer, then prevent new I/O. */
737 	raw = dev_get_drvdata(&cdev->dev);
738 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
739 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
740 	raw->flags |= RAW3215_FROZEN;
741 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
742 	return 0;
743 }
744 
745 static int raw3215_pm_start(struct ccw_device *cdev)
746 {
747 	struct raw3215_info *raw;
748 	unsigned long flags;
749 
750 	/* Allow I/O again and flush output buffer. */
751 	raw = dev_get_drvdata(&cdev->dev);
752 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
753 	raw->flags &= ~RAW3215_FROZEN;
754 	raw->flags |= RAW3215_FLUSHING;
755 	raw3215_try_io(raw);
756 	raw->flags &= ~RAW3215_FLUSHING;
757 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
758 	return 0;
759 }
760 
761 static struct ccw_device_id raw3215_id[] = {
762 	{ CCW_DEVICE(0x3215, 0) },
763 	{ /* end of list */ },
764 };
765 
766 static struct ccw_driver raw3215_ccw_driver = {
767 	.driver = {
768 		.name	= "3215",
769 		.owner	= THIS_MODULE,
770 	},
771 	.ids		= raw3215_id,
772 	.probe		= &raw3215_probe,
773 	.remove		= &raw3215_remove,
774 	.set_online	= &raw3215_set_online,
775 	.set_offline	= &raw3215_set_offline,
776 	.freeze		= &raw3215_pm_stop,
777 	.thaw		= &raw3215_pm_start,
778 	.restore	= &raw3215_pm_start,
779 };
780 
781 #ifdef CONFIG_TN3215_CONSOLE
782 /*
783  * Write a string to the 3215 console
784  */
785 static void con3215_write(struct console *co, const char *str,
786 			  unsigned int count)
787 {
788 	struct raw3215_info *raw;
789 	int i;
790 
791 	if (count <= 0)
792 		return;
793 	raw = raw3215[0];	/* console 3215 is the first one */
794 	while (count > 0) {
795 		for (i = 0; i < count; i++)
796 			if (str[i] == '\t' || str[i] == '\n')
797 				break;
798 		raw3215_write(raw, str, i);
799 		count -= i;
800 		str += i;
801 		if (count > 0) {
802 			raw3215_putchar(raw, *str);
803 			count--;
804 			str++;
805 		}
806 	}
807 }
808 
809 static struct tty_driver *con3215_device(struct console *c, int *index)
810 {
811 	*index = c->index;
812 	return tty3215_driver;
813 }
814 
815 /*
816  * panic() calls con3215_flush through a panic_notifier
817  * before the system enters a disabled, endless loop.
818  */
819 static void con3215_flush(void)
820 {
821 	struct raw3215_info *raw;
822 	unsigned long flags;
823 
824 	raw = raw3215[0];  /* console 3215 is the first one */
825 	if (raw->flags & RAW3215_FROZEN)
826 		/* The console is still frozen for suspend. */
827 		if (ccw_device_force_console())
828 			/* Forcing didn't work, no panic message .. */
829 			return;
830 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
831 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
832 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
833 }
834 
835 static int con3215_notify(struct notifier_block *self,
836 			  unsigned long event, void *data)
837 {
838 	con3215_flush();
839 	return NOTIFY_OK;
840 }
841 
842 static struct notifier_block on_panic_nb = {
843 	.notifier_call = con3215_notify,
844 	.priority = 0,
845 };
846 
847 static struct notifier_block on_reboot_nb = {
848 	.notifier_call = con3215_notify,
849 	.priority = 0,
850 };
851 
852 /*
853  *  The console structure for the 3215 console
854  */
855 static struct console con3215 = {
856 	.name	 = "ttyS",
857 	.write	 = con3215_write,
858 	.device	 = con3215_device,
859 	.flags	 = CON_PRINTBUFFER,
860 };
861 
862 /*
863  * 3215 console initialization code called from console_init().
864  */
865 static int __init con3215_init(void)
866 {
867 	struct ccw_device *cdev;
868 	struct raw3215_info *raw;
869 	struct raw3215_req *req;
870 	int i;
871 
872 	/* Check if 3215 is to be the console */
873 	if (!CONSOLE_IS_3215)
874 		return -ENODEV;
875 
876 	/* Set the console mode for VM */
877 	if (MACHINE_IS_VM) {
878 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
879 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
880 	}
881 
882 	/* allocate 3215 request structures */
883 	raw3215_freelist = NULL;
884 	spin_lock_init(&raw3215_freelist_lock);
885 	for (i = 0; i < NR_3215_REQ; i++) {
886 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
887 		req->next = raw3215_freelist;
888 		raw3215_freelist = req;
889 	}
890 
891 	cdev = ccw_device_probe_console();
892 	if (IS_ERR(cdev))
893 		return -ENODEV;
894 
895 	raw3215[0] = raw = (struct raw3215_info *)
896 		kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
897 	raw->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
898 	raw->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
899 	raw->cdev = cdev;
900 	dev_set_drvdata(&cdev->dev, raw);
901 	cdev->handler = raw3215_irq;
902 
903 	raw->flags |= RAW3215_FIXED;
904 	init_waitqueue_head(&raw->empty_wait);
905 
906 	/* Request the console irq */
907 	if (raw3215_startup(raw) != 0) {
908 		kfree(raw->inbuf);
909 		kfree(raw->buffer);
910 		kfree(raw);
911 		raw3215[0] = NULL;
912 		return -ENODEV;
913 	}
914 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
915 	register_reboot_notifier(&on_reboot_nb);
916 	register_console(&con3215);
917 	return 0;
918 }
919 console_initcall(con3215_init);
920 #endif
921 
922 /*
923  * tty3215_open
924  *
925  * This routine is called whenever a 3215 tty is opened.
926  */
927 static int tty3215_open(struct tty_struct *tty, struct file * filp)
928 {
929 	struct raw3215_info *raw;
930 	int retval, line;
931 
932 	line = tty->index;
933 	if ((line < 0) || (line >= NR_3215))
934 		return -ENODEV;
935 
936 	raw = raw3215[line];
937 	if (raw == NULL)
938 		return -ENODEV;
939 
940 	tty->driver_data = raw;
941 	raw->tty = tty;
942 
943 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
944 	/*
945 	 * Start up 3215 device
946 	 */
947 	retval = raw3215_startup(raw);
948 	if (retval)
949 		return retval;
950 
951 	return 0;
952 }
953 
954 /*
955  * tty3215_close()
956  *
957  * This routine is called when the 3215 tty is closed. We wait
958  * for the remaining request to be completed. Then we clean up.
959  */
960 static void tty3215_close(struct tty_struct *tty, struct file * filp)
961 {
962 	struct raw3215_info *raw;
963 
964 	raw = (struct raw3215_info *) tty->driver_data;
965 	if (raw == NULL || tty->count > 1)
966 		return;
967 	tty->closing = 1;
968 	/* Shutdown the terminal */
969 	raw3215_shutdown(raw);
970 	tty->closing = 0;
971 	raw->tty = NULL;
972 }
973 
974 /*
975  * Returns the amount of free space in the output buffer.
976  */
977 static int tty3215_write_room(struct tty_struct *tty)
978 {
979 	struct raw3215_info *raw;
980 
981 	raw = (struct raw3215_info *) tty->driver_data;
982 
983 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
984 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
985 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
986 	else
987 		return 0;
988 }
989 
990 /*
991  * String write routine for 3215 ttys
992  */
993 static int tty3215_write(struct tty_struct * tty,
994 			 const unsigned char *buf, int count)
995 {
996 	struct raw3215_info *raw;
997 
998 	if (!tty)
999 		return 0;
1000 	raw = (struct raw3215_info *) tty->driver_data;
1001 	raw3215_write(raw, buf, count);
1002 	return count;
1003 }
1004 
1005 /*
1006  * Put character routine for 3215 ttys
1007  */
1008 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1009 {
1010 	struct raw3215_info *raw;
1011 
1012 	if (!tty)
1013 		return 0;
1014 	raw = (struct raw3215_info *) tty->driver_data;
1015 	raw3215_putchar(raw, ch);
1016 	return 1;
1017 }
1018 
1019 static void tty3215_flush_chars(struct tty_struct *tty)
1020 {
1021 }
1022 
1023 /*
1024  * Returns the number of characters in the output buffer
1025  */
1026 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1027 {
1028 	struct raw3215_info *raw;
1029 
1030 	raw = (struct raw3215_info *) tty->driver_data;
1031 	return raw->count;
1032 }
1033 
1034 static void tty3215_flush_buffer(struct tty_struct *tty)
1035 {
1036 	struct raw3215_info *raw;
1037 
1038 	raw = (struct raw3215_info *) tty->driver_data;
1039 	raw3215_flush_buffer(raw);
1040 	tty_wakeup(tty);
1041 }
1042 
1043 /*
1044  * Disable reading from a 3215 tty
1045  */
1046 static void tty3215_throttle(struct tty_struct * tty)
1047 {
1048 	struct raw3215_info *raw;
1049 
1050 	raw = (struct raw3215_info *) tty->driver_data;
1051 	raw->flags |= RAW3215_THROTTLED;
1052 }
1053 
1054 /*
1055  * Enable reading from a 3215 tty
1056  */
1057 static void tty3215_unthrottle(struct tty_struct * tty)
1058 {
1059 	struct raw3215_info *raw;
1060 	unsigned long flags;
1061 
1062 	raw = (struct raw3215_info *) tty->driver_data;
1063 	if (raw->flags & RAW3215_THROTTLED) {
1064 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1065 		raw->flags &= ~RAW3215_THROTTLED;
1066 		raw3215_try_io(raw);
1067 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1068 	}
1069 }
1070 
1071 /*
1072  * Disable writing to a 3215 tty
1073  */
1074 static void tty3215_stop(struct tty_struct *tty)
1075 {
1076 	struct raw3215_info *raw;
1077 
1078 	raw = (struct raw3215_info *) tty->driver_data;
1079 	raw->flags |= RAW3215_STOPPED;
1080 }
1081 
1082 /*
1083  * Enable writing to a 3215 tty
1084  */
1085 static void tty3215_start(struct tty_struct *tty)
1086 {
1087 	struct raw3215_info *raw;
1088 	unsigned long flags;
1089 
1090 	raw = (struct raw3215_info *) tty->driver_data;
1091 	if (raw->flags & RAW3215_STOPPED) {
1092 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1093 		raw->flags &= ~RAW3215_STOPPED;
1094 		raw3215_try_io(raw);
1095 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1096 	}
1097 }
1098 
1099 static const struct tty_operations tty3215_ops = {
1100 	.open = tty3215_open,
1101 	.close = tty3215_close,
1102 	.write = tty3215_write,
1103 	.put_char = tty3215_put_char,
1104 	.flush_chars = tty3215_flush_chars,
1105 	.write_room = tty3215_write_room,
1106 	.chars_in_buffer = tty3215_chars_in_buffer,
1107 	.flush_buffer = tty3215_flush_buffer,
1108 	.throttle = tty3215_throttle,
1109 	.unthrottle = tty3215_unthrottle,
1110 	.stop = tty3215_stop,
1111 	.start = tty3215_start,
1112 };
1113 
1114 /*
1115  * 3215 tty registration code called from tty_init().
1116  * Most kernel services (incl. kmalloc) are available at this poimt.
1117  */
1118 static int __init 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 		put_tty_driver(driver);
1157 		return ret;
1158 	}
1159 	tty3215_driver = driver;
1160 	return 0;
1161 }
1162 
1163 static void __exit tty3215_exit(void)
1164 {
1165 	tty_unregister_driver(tty3215_driver);
1166 	put_tty_driver(tty3215_driver);
1167 	ccw_driver_unregister(&raw3215_ccw_driver);
1168 }
1169 
1170 module_init(tty3215_init);
1171 module_exit(tty3215_exit);
1172