xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 95e9fd10)
1 /*
2  * 3215 line mode terminal driver.
3  *
4  * Copyright IBM Corp. 1999, 2009
5  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6  *
7  * Updated:
8  *  Aug-2000: Added tab support
9  *	      Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kdev_t.h>
15 #include <linux/tty.h>
16 #include <linux/tty_flip.h>
17 #include <linux/vt_kern.h>
18 #include <linux/init.h>
19 #include <linux/console.h>
20 #include <linux/interrupt.h>
21 #include <linux/err.h>
22 #include <linux/reboot.h>
23 #include <linux/serial.h> /* ASYNC_* flags */
24 #include <linux/slab.h>
25 #include <asm/ccwdev.h>
26 #include <asm/cio.h>
27 #include <asm/io.h>
28 #include <asm/ebcdic.h>
29 #include <asm/uaccess.h>
30 #include <asm/delay.h>
31 #include <asm/cpcmd.h>
32 #include <asm/setup.h>
33 
34 #include "ctrlchar.h"
35 
36 #define NR_3215		    1
37 #define NR_3215_REQ	    (4*NR_3215)
38 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
39 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
40 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
41 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
42 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
43 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
44 #define RAW3215_NR_CCWS	    3
45 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
46 
47 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
48 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
49 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
50 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
51 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
52 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
53 
54 #define TAB_STOP_SIZE	    8	      /* tab stop size */
55 
56 /*
57  * Request types for a 3215 device
58  */
59 enum raw3215_type {
60 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
61 };
62 
63 /*
64  * Request structure for a 3215 device
65  */
66 struct raw3215_req {
67 	enum raw3215_type type;	      /* type of the request */
68 	int start, len;		      /* start index & len in output buffer */
69 	int delayable;		      /* indication to wait for more data */
70 	int residual;		      /* residual count for read request */
71 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
72 	struct raw3215_info *info;    /* pointer to main structure */
73 	struct raw3215_req *next;     /* pointer to next request */
74 } __attribute__ ((aligned(8)));
75 
76 struct raw3215_info {
77 	struct tty_port port;
78 	struct ccw_device *cdev;      /* device for tty driver */
79 	spinlock_t *lock;	      /* pointer to irq lock */
80 	int flags;		      /* state flags */
81 	char *buffer;		      /* pointer to output buffer */
82 	char *inbuf;		      /* pointer to input buffer */
83 	int head;		      /* first free byte in output buffer */
84 	int count;		      /* number of bytes in output buffer */
85 	int written;		      /* number of bytes in write requests */
86 	struct raw3215_req *queued_read; /* pointer to queued read requests */
87 	struct raw3215_req *queued_write;/* pointer to queued write requests */
88 	struct tasklet_struct tlet;   /* tasklet to invoke tty_wakeup */
89 	wait_queue_head_t empty_wait; /* wait queue for flushing */
90 	struct timer_list timer;      /* timer for delayed output */
91 	int line_pos;		      /* position on the line (for tabs) */
92 	char ubuffer[80];	      /* copy_from_user buffer */
93 };
94 
95 /* array of 3215 devices structures */
96 static struct raw3215_info *raw3215[NR_3215];
97 /* spinlock to protect the raw3215 array */
98 static DEFINE_SPINLOCK(raw3215_device_lock);
99 /* list of free request structures */
100 static struct raw3215_req *raw3215_freelist;
101 /* spinlock to protect free list */
102 static spinlock_t raw3215_freelist_lock;
103 
104 static struct tty_driver *tty3215_driver;
105 
106 /*
107  * Get a request structure from the free list
108  */
109 static inline struct raw3215_req *raw3215_alloc_req(void)
110 {
111 	struct raw3215_req *req;
112 	unsigned long flags;
113 
114 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
115 	req = raw3215_freelist;
116 	raw3215_freelist = req->next;
117 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
118 	return req;
119 }
120 
121 /*
122  * Put a request structure back to the free list
123  */
124 static inline void raw3215_free_req(struct raw3215_req *req)
125 {
126 	unsigned long flags;
127 
128 	if (req->type == RAW3215_FREE)
129 		return;		/* don't free a free request */
130 	req->type = RAW3215_FREE;
131 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
132 	req->next = raw3215_freelist;
133 	raw3215_freelist = req;
134 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
135 }
136 
137 /*
138  * Set up a read request that reads up to 160 byte from the 3215 device.
139  * If there is a queued read request it is used, but that shouldn't happen
140  * because a 3215 terminal won't accept a new read before the old one is
141  * completed.
142  */
143 static void raw3215_mk_read_req(struct raw3215_info *raw)
144 {
145 	struct raw3215_req *req;
146 	struct ccw1 *ccw;
147 
148 	/* there can only be ONE read request at a time */
149 	req = raw->queued_read;
150 	if (req == NULL) {
151 		/* no queued read request, use new req structure */
152 		req = raw3215_alloc_req();
153 		req->type = RAW3215_READ;
154 		req->info = raw;
155 		raw->queued_read = req;
156 	}
157 
158 	ccw = req->ccws;
159 	ccw->cmd_code = 0x0A; /* read inquiry */
160 	ccw->flags = 0x20;    /* ignore incorrect length */
161 	ccw->count = 160;
162 	ccw->cda = (__u32) __pa(raw->inbuf);
163 }
164 
165 /*
166  * Set up a write request with the information from the main structure.
167  * A ccw chain is created that writes as much as possible from the output
168  * buffer to the 3215 device. If a queued write exists it is replaced by
169  * the new, probably lengthened request.
170  */
171 static void raw3215_mk_write_req(struct raw3215_info *raw)
172 {
173 	struct raw3215_req *req;
174 	struct ccw1 *ccw;
175 	int len, count, ix, lines;
176 
177 	if (raw->count <= raw->written)
178 		return;
179 	/* check if there is a queued write request */
180 	req = raw->queued_write;
181 	if (req == NULL) {
182 		/* no queued write request, use new req structure */
183 		req = raw3215_alloc_req();
184 		req->type = RAW3215_WRITE;
185 		req->info = raw;
186 		raw->queued_write = req;
187 	} else {
188 		raw->written -= req->len;
189 	}
190 
191 	ccw = req->ccws;
192 	req->start = (raw->head - raw->count + raw->written) &
193 		     (RAW3215_BUFFER_SIZE - 1);
194 	/*
195 	 * now we have to count newlines. We can at max accept
196 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
197 	 * a restriction in VM
198 	 */
199 	lines = 0;
200 	ix = req->start;
201 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
202 		if (raw->buffer[ix] == 0x15)
203 			lines++;
204 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
205 	}
206 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
207 	if (len > RAW3215_MAX_BYTES)
208 		len = RAW3215_MAX_BYTES;
209 	req->len = len;
210 	raw->written += len;
211 
212 	/* set the indication if we should try to enlarge this request */
213 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
214 
215 	ix = req->start;
216 	while (len > 0) {
217 		if (ccw > req->ccws)
218 			ccw[-1].flags |= 0x40; /* use command chaining */
219 		ccw->cmd_code = 0x01; /* write, auto carrier return */
220 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
221 		ccw->cda =
222 			(__u32) __pa(raw->buffer + ix);
223 		count = len;
224 		if (ix + count > RAW3215_BUFFER_SIZE)
225 			count = RAW3215_BUFFER_SIZE - ix;
226 		ccw->count = count;
227 		len -= count;
228 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
229 		ccw++;
230 	}
231 	/*
232 	 * Add a NOP to the channel program. 3215 devices are purely
233 	 * emulated and its much better to avoid the channel end
234 	 * interrupt in this case.
235 	 */
236 	if (ccw > req->ccws)
237 		ccw[-1].flags |= 0x40; /* use command chaining */
238 	ccw->cmd_code = 0x03; /* NOP */
239 	ccw->flags = 0;
240 	ccw->cda = 0;
241 	ccw->count = 1;
242 }
243 
244 /*
245  * Start a read or a write request
246  */
247 static void raw3215_start_io(struct raw3215_info *raw)
248 {
249 	struct raw3215_req *req;
250 	int res;
251 
252 	req = raw->queued_read;
253 	if (req != NULL &&
254 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
255 		/* dequeue request */
256 		raw->queued_read = NULL;
257 		res = ccw_device_start(raw->cdev, req->ccws,
258 				       (unsigned long) req, 0, 0);
259 		if (res != 0) {
260 			/* do_IO failed, put request back to queue */
261 			raw->queued_read = req;
262 		} else {
263 			raw->flags |= RAW3215_WORKING;
264 		}
265 	}
266 	req = raw->queued_write;
267 	if (req != NULL &&
268 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
269 		/* dequeue request */
270 		raw->queued_write = NULL;
271 		res = ccw_device_start(raw->cdev, req->ccws,
272 				       (unsigned long) req, 0, 0);
273 		if (res != 0) {
274 			/* do_IO failed, put request back to queue */
275 			raw->queued_write = req;
276 		} else {
277 			raw->flags |= RAW3215_WORKING;
278 		}
279 	}
280 }
281 
282 /*
283  * Function to start a delayed output after RAW3215_TIMEOUT seconds
284  */
285 static void raw3215_timeout(unsigned long __data)
286 {
287 	struct raw3215_info *raw = (struct raw3215_info *) __data;
288 	unsigned long flags;
289 
290 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
291 	if (raw->flags & RAW3215_TIMER_RUNS) {
292 		del_timer(&raw->timer);
293 		raw->flags &= ~RAW3215_TIMER_RUNS;
294 		if (!(raw->port.flags & ASYNC_SUSPENDED)) {
295 			raw3215_mk_write_req(raw);
296 			raw3215_start_io(raw);
297 		}
298 	}
299 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
300 }
301 
302 /*
303  * Function to conditionally start an IO. A read is started immediately,
304  * a write is only started immediately if the flush flag is on or the
305  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
306  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
307  */
308 static inline void raw3215_try_io(struct raw3215_info *raw)
309 {
310 	if (!(raw->port.flags & ASYNC_INITIALIZED) ||
311 			(raw->port.flags & ASYNC_SUSPENDED))
312 		return;
313 	if (raw->queued_read != NULL)
314 		raw3215_start_io(raw);
315 	else if (raw->queued_write != NULL) {
316 		if ((raw->queued_write->delayable == 0) ||
317 		    (raw->flags & RAW3215_FLUSHING)) {
318 			/* execute write requests bigger than minimum size */
319 			raw3215_start_io(raw);
320 			if (raw->flags & RAW3215_TIMER_RUNS) {
321 				del_timer(&raw->timer);
322 				raw->flags &= ~RAW3215_TIMER_RUNS;
323 			}
324 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
325 			/* delay small writes */
326 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
327 			add_timer(&raw->timer);
328 			raw->flags |= RAW3215_TIMER_RUNS;
329 		}
330 	}
331 }
332 
333 /*
334  * Call tty_wakeup from tasklet context
335  */
336 static void raw3215_wakeup(unsigned long data)
337 {
338 	struct raw3215_info *raw = (struct raw3215_info *) data;
339 	struct tty_struct *tty;
340 
341 	tty = tty_port_tty_get(&raw->port);
342 	tty_wakeup(tty);
343 	tty_kref_put(tty);
344 }
345 
346 /*
347  * Try to start the next IO and wake up processes waiting on the tty.
348  */
349 static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
350 {
351 	raw3215_mk_write_req(raw);
352 	raw3215_try_io(raw);
353 	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
354 		tasklet_schedule(&raw->tlet);
355 }
356 
357 /*
358  * Interrupt routine, called from common io layer
359  */
360 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
361 			struct irb *irb)
362 {
363 	struct raw3215_info *raw;
364 	struct raw3215_req *req;
365 	struct tty_struct *tty;
366 	int cstat, dstat;
367 	int count;
368 
369 	raw = dev_get_drvdata(&cdev->dev);
370 	req = (struct raw3215_req *) intparm;
371 	tty = tty_port_tty_get(&raw->port);
372 	cstat = irb->scsw.cmd.cstat;
373 	dstat = irb->scsw.cmd.dstat;
374 	if (cstat != 0)
375 		raw3215_next_io(raw, tty);
376 	if (dstat & 0x01) { /* we got a unit exception */
377 		dstat &= ~0x01;	 /* we can ignore it */
378 	}
379 	switch (dstat) {
380 	case 0x80:
381 		if (cstat != 0)
382 			break;
383 		/* Attention interrupt, someone hit the enter key */
384 		raw3215_mk_read_req(raw);
385 		raw3215_next_io(raw, tty);
386 		break;
387 	case 0x08:
388 	case 0x0C:
389 		/* Channel end interrupt. */
390 		if ((raw = req->info) == NULL)
391 			goto put_tty;	     /* That shouldn't happen ... */
392 		if (req->type == RAW3215_READ) {
393 			/* store residual count, then wait for device end */
394 			req->residual = irb->scsw.cmd.count;
395 		}
396 		if (dstat == 0x08)
397 			break;
398 	case 0x04:
399 		/* Device end interrupt. */
400 		if ((raw = req->info) == NULL)
401 			goto put_tty;	     /* That shouldn't happen ... */
402 		if (req->type == RAW3215_READ && tty != NULL) {
403 			unsigned int cchar;
404 
405 			count = 160 - req->residual;
406 			EBCASC(raw->inbuf, count);
407 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
408 			switch (cchar & CTRLCHAR_MASK) {
409 			case CTRLCHAR_SYSRQ:
410 				break;
411 
412 			case CTRLCHAR_CTRL:
413 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
414 				tty_flip_buffer_push(tty);
415 				break;
416 
417 			case CTRLCHAR_NONE:
418 				if (count < 2 ||
419 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
420 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
421 					/* add the auto \n */
422 					raw->inbuf[count] = '\n';
423 					count++;
424 				} else
425 					count -= 2;
426 				tty_insert_flip_string(tty, raw->inbuf, count);
427 				tty_flip_buffer_push(tty);
428 				break;
429 			}
430 		} else if (req->type == RAW3215_WRITE) {
431 			raw->count -= req->len;
432 			raw->written -= req->len;
433 		}
434 		raw->flags &= ~RAW3215_WORKING;
435 		raw3215_free_req(req);
436 		/* check for empty wait */
437 		if (waitqueue_active(&raw->empty_wait) &&
438 		    raw->queued_write == NULL &&
439 		    raw->queued_read == NULL) {
440 			wake_up_interruptible(&raw->empty_wait);
441 		}
442 		raw3215_next_io(raw, tty);
443 		break;
444 	default:
445 		/* Strange interrupt, I'll do my best to clean up */
446 		if (req != NULL && req->type != RAW3215_FREE) {
447 			if (req->type == RAW3215_WRITE) {
448 				raw->count -= req->len;
449 				raw->written -= req->len;
450 			}
451 			raw->flags &= ~RAW3215_WORKING;
452 			raw3215_free_req(req);
453 		}
454 		raw3215_next_io(raw, tty);
455 	}
456 put_tty:
457 	tty_kref_put(tty);
458 }
459 
460 /*
461  * Drop the oldest line from the output buffer.
462  */
463 static void raw3215_drop_line(struct raw3215_info *raw)
464 {
465 	int ix;
466 	char ch;
467 
468 	BUG_ON(raw->written != 0);
469 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
470 	while (raw->count > 0) {
471 		ch = raw->buffer[ix];
472 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
473 		raw->count--;
474 		if (ch == 0x15)
475 			break;
476 	}
477 	raw->head = ix;
478 }
479 
480 /*
481  * Wait until length bytes are available int the output buffer.
482  * Has to be called with the s390irq lock held. Can be called
483  * disabled.
484  */
485 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
486 {
487 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
488 		/* While console is frozen for suspend we have no other
489 		 * choice but to drop message from the buffer to make
490 		 * room for even more messages. */
491 		if (raw->port.flags & ASYNC_SUSPENDED) {
492 			raw3215_drop_line(raw);
493 			continue;
494 		}
495 		/* there might be a request pending */
496 		raw->flags |= RAW3215_FLUSHING;
497 		raw3215_mk_write_req(raw);
498 		raw3215_try_io(raw);
499 		raw->flags &= ~RAW3215_FLUSHING;
500 #ifdef CONFIG_TN3215_CONSOLE
501 		wait_cons_dev();
502 #endif
503 		/* Enough room freed up ? */
504 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
505 			break;
506 		/* there might be another cpu waiting for the lock */
507 		spin_unlock(get_ccwdev_lock(raw->cdev));
508 		udelay(100);
509 		spin_lock(get_ccwdev_lock(raw->cdev));
510 	}
511 }
512 
513 /*
514  * String write routine for 3215 devices
515  */
516 static void raw3215_write(struct raw3215_info *raw, const char *str,
517 			  unsigned int length)
518 {
519 	unsigned long flags;
520 	int c, count;
521 
522 	while (length > 0) {
523 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
524 		count = (length > RAW3215_BUFFER_SIZE) ?
525 					     RAW3215_BUFFER_SIZE : length;
526 		length -= count;
527 
528 		raw3215_make_room(raw, count);
529 
530 		/* copy string to output buffer and convert it to EBCDIC */
531 		while (1) {
532 			c = min_t(int, count,
533 				  min(RAW3215_BUFFER_SIZE - raw->count,
534 				      RAW3215_BUFFER_SIZE - raw->head));
535 			if (c <= 0)
536 				break;
537 			memcpy(raw->buffer + raw->head, str, c);
538 			ASCEBC(raw->buffer + raw->head, c);
539 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
540 			raw->count += c;
541 			raw->line_pos += c;
542 			str += c;
543 			count -= c;
544 		}
545 		if (!(raw->flags & RAW3215_WORKING)) {
546 			raw3215_mk_write_req(raw);
547 			/* start or queue request */
548 			raw3215_try_io(raw);
549 		}
550 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
551 	}
552 }
553 
554 /*
555  * Put character routine for 3215 devices
556  */
557 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
558 {
559 	unsigned long flags;
560 	unsigned int length, i;
561 
562 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
563 	if (ch == '\t') {
564 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
565 		raw->line_pos += length;
566 		ch = ' ';
567 	} else if (ch == '\n') {
568 		length = 1;
569 		raw->line_pos = 0;
570 	} else {
571 		length = 1;
572 		raw->line_pos++;
573 	}
574 	raw3215_make_room(raw, length);
575 
576 	for (i = 0; i < length; i++) {
577 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
578 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
579 		raw->count++;
580 	}
581 	if (!(raw->flags & RAW3215_WORKING)) {
582 		raw3215_mk_write_req(raw);
583 		/* start or queue request */
584 		raw3215_try_io(raw);
585 	}
586 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
587 }
588 
589 /*
590  * Flush routine, it simply sets the flush flag and tries to start
591  * pending IO.
592  */
593 static void raw3215_flush_buffer(struct raw3215_info *raw)
594 {
595 	unsigned long flags;
596 
597 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
598 	if (raw->count > 0) {
599 		raw->flags |= RAW3215_FLUSHING;
600 		raw3215_try_io(raw);
601 		raw->flags &= ~RAW3215_FLUSHING;
602 	}
603 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
604 }
605 
606 /*
607  * Fire up a 3215 device.
608  */
609 static int raw3215_startup(struct raw3215_info *raw)
610 {
611 	unsigned long flags;
612 
613 	if (raw->port.flags & ASYNC_INITIALIZED)
614 		return 0;
615 	raw->line_pos = 0;
616 	raw->port.flags |= ASYNC_INITIALIZED;
617 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
618 	raw3215_try_io(raw);
619 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
620 
621 	return 0;
622 }
623 
624 /*
625  * Shutdown a 3215 device.
626  */
627 static void raw3215_shutdown(struct raw3215_info *raw)
628 {
629 	DECLARE_WAITQUEUE(wait, current);
630 	unsigned long flags;
631 
632 	if (!(raw->port.flags & ASYNC_INITIALIZED) ||
633 			(raw->flags & RAW3215_FIXED))
634 		return;
635 	/* Wait for outstanding requests, then free irq */
636 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
637 	if ((raw->flags & RAW3215_WORKING) ||
638 	    raw->queued_write != NULL ||
639 	    raw->queued_read != NULL) {
640 		raw->port.flags |= ASYNC_CLOSING;
641 		add_wait_queue(&raw->empty_wait, &wait);
642 		set_current_state(TASK_INTERRUPTIBLE);
643 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
644 		schedule();
645 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
646 		remove_wait_queue(&raw->empty_wait, &wait);
647 		set_current_state(TASK_RUNNING);
648 		raw->port.flags &= ~(ASYNC_INITIALIZED | ASYNC_CLOSING);
649 	}
650 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
651 }
652 
653 static struct raw3215_info *raw3215_alloc_info(void)
654 {
655 	struct raw3215_info *info;
656 
657 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
658 	if (!info)
659 		return NULL;
660 
661 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
662 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
663 	if (!info->buffer || !info->inbuf) {
664 		kfree(info);
665 		return NULL;
666 	}
667 
668 	setup_timer(&info->timer, raw3215_timeout, (unsigned long)info);
669 	init_waitqueue_head(&info->empty_wait);
670 	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
671 	tty_port_init(&info->port);
672 
673 	return info;
674 }
675 
676 static void raw3215_free_info(struct raw3215_info *raw)
677 {
678 	kfree(raw->inbuf);
679 	kfree(raw->buffer);
680 	kfree(raw);
681 }
682 
683 static int raw3215_probe (struct ccw_device *cdev)
684 {
685 	struct raw3215_info *raw;
686 	int line;
687 
688 	/* Console is special. */
689 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
690 		return 0;
691 
692 	raw = raw3215_alloc_info();
693 	if (raw == NULL)
694 		return -ENOMEM;
695 
696 	raw->cdev = cdev;
697 	dev_set_drvdata(&cdev->dev, raw);
698 	cdev->handler = raw3215_irq;
699 
700 	spin_lock(&raw3215_device_lock);
701 	for (line = 0; line < NR_3215; line++) {
702 		if (!raw3215[line]) {
703 			raw3215[line] = raw;
704 			break;
705 		}
706 	}
707 	spin_unlock(&raw3215_device_lock);
708 	if (line == NR_3215) {
709 		raw3215_free_info(raw);
710 		return -ENODEV;
711 	}
712 
713 	return 0;
714 }
715 
716 static void raw3215_remove (struct ccw_device *cdev)
717 {
718 	struct raw3215_info *raw;
719 
720 	ccw_device_set_offline(cdev);
721 	raw = dev_get_drvdata(&cdev->dev);
722 	if (raw) {
723 		dev_set_drvdata(&cdev->dev, NULL);
724 		raw3215_free_info(raw);
725 	}
726 }
727 
728 static int raw3215_set_online (struct ccw_device *cdev)
729 {
730 	struct raw3215_info *raw;
731 
732 	raw = dev_get_drvdata(&cdev->dev);
733 	if (!raw)
734 		return -ENODEV;
735 
736 	return raw3215_startup(raw);
737 }
738 
739 static int raw3215_set_offline (struct ccw_device *cdev)
740 {
741 	struct raw3215_info *raw;
742 
743 	raw = dev_get_drvdata(&cdev->dev);
744 	if (!raw)
745 		return -ENODEV;
746 
747 	raw3215_shutdown(raw);
748 
749 	return 0;
750 }
751 
752 static int raw3215_pm_stop(struct ccw_device *cdev)
753 {
754 	struct raw3215_info *raw;
755 	unsigned long flags;
756 
757 	/* Empty the output buffer, then prevent new I/O. */
758 	raw = dev_get_drvdata(&cdev->dev);
759 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
760 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
761 	raw->port.flags |= ASYNC_SUSPENDED;
762 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
763 	return 0;
764 }
765 
766 static int raw3215_pm_start(struct ccw_device *cdev)
767 {
768 	struct raw3215_info *raw;
769 	unsigned long flags;
770 
771 	/* Allow I/O again and flush output buffer. */
772 	raw = dev_get_drvdata(&cdev->dev);
773 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
774 	raw->port.flags &= ~ASYNC_SUSPENDED;
775 	raw->flags |= RAW3215_FLUSHING;
776 	raw3215_try_io(raw);
777 	raw->flags &= ~RAW3215_FLUSHING;
778 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
779 	return 0;
780 }
781 
782 static struct ccw_device_id raw3215_id[] = {
783 	{ CCW_DEVICE(0x3215, 0) },
784 	{ /* end of list */ },
785 };
786 
787 static struct ccw_driver raw3215_ccw_driver = {
788 	.driver = {
789 		.name	= "3215",
790 		.owner	= THIS_MODULE,
791 	},
792 	.ids		= raw3215_id,
793 	.probe		= &raw3215_probe,
794 	.remove		= &raw3215_remove,
795 	.set_online	= &raw3215_set_online,
796 	.set_offline	= &raw3215_set_offline,
797 	.freeze		= &raw3215_pm_stop,
798 	.thaw		= &raw3215_pm_start,
799 	.restore	= &raw3215_pm_start,
800 	.int_class	= IOINT_C15,
801 };
802 
803 #ifdef CONFIG_TN3215_CONSOLE
804 /*
805  * Write a string to the 3215 console
806  */
807 static void con3215_write(struct console *co, const char *str,
808 			  unsigned int count)
809 {
810 	struct raw3215_info *raw;
811 	int i;
812 
813 	if (count <= 0)
814 		return;
815 	raw = raw3215[0];	/* console 3215 is the first one */
816 	while (count > 0) {
817 		for (i = 0; i < count; i++)
818 			if (str[i] == '\t' || str[i] == '\n')
819 				break;
820 		raw3215_write(raw, str, i);
821 		count -= i;
822 		str += i;
823 		if (count > 0) {
824 			raw3215_putchar(raw, *str);
825 			count--;
826 			str++;
827 		}
828 	}
829 }
830 
831 static struct tty_driver *con3215_device(struct console *c, int *index)
832 {
833 	*index = c->index;
834 	return tty3215_driver;
835 }
836 
837 /*
838  * panic() calls con3215_flush through a panic_notifier
839  * before the system enters a disabled, endless loop.
840  */
841 static void con3215_flush(void)
842 {
843 	struct raw3215_info *raw;
844 	unsigned long flags;
845 
846 	raw = raw3215[0];  /* console 3215 is the first one */
847 	if (raw->port.flags & ASYNC_SUSPENDED)
848 		/* The console is still frozen for suspend. */
849 		if (ccw_device_force_console())
850 			/* Forcing didn't work, no panic message .. */
851 			return;
852 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
853 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
854 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
855 }
856 
857 static int con3215_notify(struct notifier_block *self,
858 			  unsigned long event, void *data)
859 {
860 	con3215_flush();
861 	return NOTIFY_OK;
862 }
863 
864 static struct notifier_block on_panic_nb = {
865 	.notifier_call = con3215_notify,
866 	.priority = 0,
867 };
868 
869 static struct notifier_block on_reboot_nb = {
870 	.notifier_call = con3215_notify,
871 	.priority = 0,
872 };
873 
874 /*
875  *  The console structure for the 3215 console
876  */
877 static struct console con3215 = {
878 	.name	 = "ttyS",
879 	.write	 = con3215_write,
880 	.device	 = con3215_device,
881 	.flags	 = CON_PRINTBUFFER,
882 };
883 
884 /*
885  * 3215 console initialization code called from console_init().
886  */
887 static int __init con3215_init(void)
888 {
889 	struct ccw_device *cdev;
890 	struct raw3215_info *raw;
891 	struct raw3215_req *req;
892 	int i;
893 
894 	/* Check if 3215 is to be the console */
895 	if (!CONSOLE_IS_3215)
896 		return -ENODEV;
897 
898 	/* Set the console mode for VM */
899 	if (MACHINE_IS_VM) {
900 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
901 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
902 	}
903 
904 	/* allocate 3215 request structures */
905 	raw3215_freelist = NULL;
906 	spin_lock_init(&raw3215_freelist_lock);
907 	for (i = 0; i < NR_3215_REQ; i++) {
908 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
909 		req->next = raw3215_freelist;
910 		raw3215_freelist = req;
911 	}
912 
913 	cdev = ccw_device_probe_console();
914 	if (IS_ERR(cdev))
915 		return -ENODEV;
916 
917 	raw3215[0] = raw = raw3215_alloc_info();
918 	raw->cdev = cdev;
919 	dev_set_drvdata(&cdev->dev, raw);
920 	cdev->handler = raw3215_irq;
921 
922 	raw->flags |= RAW3215_FIXED;
923 
924 	/* Request the console irq */
925 	if (raw3215_startup(raw) != 0) {
926 		raw3215_free_info(raw);
927 		raw3215[0] = NULL;
928 		return -ENODEV;
929 	}
930 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
931 	register_reboot_notifier(&on_reboot_nb);
932 	register_console(&con3215);
933 	return 0;
934 }
935 console_initcall(con3215_init);
936 #endif
937 
938 /*
939  * tty3215_open
940  *
941  * This routine is called whenever a 3215 tty is opened.
942  */
943 static int tty3215_open(struct tty_struct *tty, struct file * filp)
944 {
945 	struct raw3215_info *raw;
946 	int retval;
947 
948 	raw = raw3215[tty->index];
949 	if (raw == NULL)
950 		return -ENODEV;
951 
952 	tty->driver_data = raw;
953 	tty_port_tty_set(&raw->port, tty);
954 
955 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
956 	/*
957 	 * Start up 3215 device
958 	 */
959 	retval = raw3215_startup(raw);
960 	if (retval)
961 		return retval;
962 
963 	return 0;
964 }
965 
966 /*
967  * tty3215_close()
968  *
969  * This routine is called when the 3215 tty is closed. We wait
970  * for the remaining request to be completed. Then we clean up.
971  */
972 static void tty3215_close(struct tty_struct *tty, struct file * filp)
973 {
974 	struct raw3215_info *raw;
975 
976 	raw = (struct raw3215_info *) tty->driver_data;
977 	if (raw == NULL || tty->count > 1)
978 		return;
979 	tty->closing = 1;
980 	/* Shutdown the terminal */
981 	raw3215_shutdown(raw);
982 	tasklet_kill(&raw->tlet);
983 	tty->closing = 0;
984 	tty_port_tty_set(&raw->port, NULL);
985 }
986 
987 /*
988  * Returns the amount of free space in the output buffer.
989  */
990 static int tty3215_write_room(struct tty_struct *tty)
991 {
992 	struct raw3215_info *raw;
993 
994 	raw = (struct raw3215_info *) tty->driver_data;
995 
996 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
997 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
998 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
999 	else
1000 		return 0;
1001 }
1002 
1003 /*
1004  * String write routine for 3215 ttys
1005  */
1006 static int tty3215_write(struct tty_struct * tty,
1007 			 const unsigned char *buf, int count)
1008 {
1009 	struct raw3215_info *raw;
1010 
1011 	if (!tty)
1012 		return 0;
1013 	raw = (struct raw3215_info *) tty->driver_data;
1014 	raw3215_write(raw, buf, count);
1015 	return count;
1016 }
1017 
1018 /*
1019  * Put character routine for 3215 ttys
1020  */
1021 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1022 {
1023 	struct raw3215_info *raw;
1024 
1025 	if (!tty)
1026 		return 0;
1027 	raw = (struct raw3215_info *) tty->driver_data;
1028 	raw3215_putchar(raw, ch);
1029 	return 1;
1030 }
1031 
1032 static void tty3215_flush_chars(struct tty_struct *tty)
1033 {
1034 }
1035 
1036 /*
1037  * Returns the number of characters in the output buffer
1038  */
1039 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1040 {
1041 	struct raw3215_info *raw;
1042 
1043 	raw = (struct raw3215_info *) tty->driver_data;
1044 	return raw->count;
1045 }
1046 
1047 static void tty3215_flush_buffer(struct tty_struct *tty)
1048 {
1049 	struct raw3215_info *raw;
1050 
1051 	raw = (struct raw3215_info *) tty->driver_data;
1052 	raw3215_flush_buffer(raw);
1053 	tty_wakeup(tty);
1054 }
1055 
1056 /*
1057  * Disable reading from a 3215 tty
1058  */
1059 static void tty3215_throttle(struct tty_struct * tty)
1060 {
1061 	struct raw3215_info *raw;
1062 
1063 	raw = (struct raw3215_info *) tty->driver_data;
1064 	raw->flags |= RAW3215_THROTTLED;
1065 }
1066 
1067 /*
1068  * Enable reading from a 3215 tty
1069  */
1070 static void tty3215_unthrottle(struct tty_struct * tty)
1071 {
1072 	struct raw3215_info *raw;
1073 	unsigned long flags;
1074 
1075 	raw = (struct raw3215_info *) tty->driver_data;
1076 	if (raw->flags & RAW3215_THROTTLED) {
1077 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1078 		raw->flags &= ~RAW3215_THROTTLED;
1079 		raw3215_try_io(raw);
1080 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1081 	}
1082 }
1083 
1084 /*
1085  * Disable writing to a 3215 tty
1086  */
1087 static void tty3215_stop(struct tty_struct *tty)
1088 {
1089 	struct raw3215_info *raw;
1090 
1091 	raw = (struct raw3215_info *) tty->driver_data;
1092 	raw->flags |= RAW3215_STOPPED;
1093 }
1094 
1095 /*
1096  * Enable writing to a 3215 tty
1097  */
1098 static void tty3215_start(struct tty_struct *tty)
1099 {
1100 	struct raw3215_info *raw;
1101 	unsigned long flags;
1102 
1103 	raw = (struct raw3215_info *) tty->driver_data;
1104 	if (raw->flags & RAW3215_STOPPED) {
1105 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1106 		raw->flags &= ~RAW3215_STOPPED;
1107 		raw3215_try_io(raw);
1108 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1109 	}
1110 }
1111 
1112 static const struct tty_operations tty3215_ops = {
1113 	.open = tty3215_open,
1114 	.close = tty3215_close,
1115 	.write = tty3215_write,
1116 	.put_char = tty3215_put_char,
1117 	.flush_chars = tty3215_flush_chars,
1118 	.write_room = tty3215_write_room,
1119 	.chars_in_buffer = tty3215_chars_in_buffer,
1120 	.flush_buffer = tty3215_flush_buffer,
1121 	.throttle = tty3215_throttle,
1122 	.unthrottle = tty3215_unthrottle,
1123 	.stop = tty3215_stop,
1124 	.start = tty3215_start,
1125 };
1126 
1127 /*
1128  * 3215 tty registration code called from tty_init().
1129  * Most kernel services (incl. kmalloc) are available at this poimt.
1130  */
1131 static int __init tty3215_init(void)
1132 {
1133 	struct tty_driver *driver;
1134 	int ret;
1135 
1136 	if (!CONSOLE_IS_3215)
1137 		return 0;
1138 
1139 	driver = alloc_tty_driver(NR_3215);
1140 	if (!driver)
1141 		return -ENOMEM;
1142 
1143 	ret = ccw_driver_register(&raw3215_ccw_driver);
1144 	if (ret) {
1145 		put_tty_driver(driver);
1146 		return ret;
1147 	}
1148 	/*
1149 	 * Initialize the tty_driver structure
1150 	 * Entries in tty3215_driver that are NOT initialized:
1151 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1152 	 */
1153 
1154 	driver->driver_name = "tty3215";
1155 	driver->name = "ttyS";
1156 	driver->major = TTY_MAJOR;
1157 	driver->minor_start = 64;
1158 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1159 	driver->subtype = SYSTEM_TYPE_TTY;
1160 	driver->init_termios = tty_std_termios;
1161 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1162 	driver->init_termios.c_oflag = ONLCR | XTABS;
1163 	driver->init_termios.c_lflag = ISIG;
1164 	driver->flags = TTY_DRIVER_REAL_RAW;
1165 	tty_set_operations(driver, &tty3215_ops);
1166 	ret = tty_register_driver(driver);
1167 	if (ret) {
1168 		put_tty_driver(driver);
1169 		return ret;
1170 	}
1171 	tty3215_driver = driver;
1172 	return 0;
1173 }
1174 
1175 static void __exit tty3215_exit(void)
1176 {
1177 	tty_unregister_driver(tty3215_driver);
1178 	put_tty_driver(tty3215_driver);
1179 	ccw_driver_unregister(&raw3215_ccw_driver);
1180 }
1181 
1182 module_init(tty3215_init);
1183 module_exit(tty3215_exit);
1184