xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 7dd65feb)
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/slab.h>
24 #include <asm/ccwdev.h>
25 #include <asm/cio.h>
26 #include <asm/io.h>
27 #include <asm/ebcdic.h>
28 #include <asm/uaccess.h>
29 #include <asm/delay.h>
30 #include <asm/cpcmd.h>
31 #include <asm/setup.h>
32 
33 #include "ctrlchar.h"
34 
35 #define NR_3215		    1
36 #define NR_3215_REQ	    (4*NR_3215)
37 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
38 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
39 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
40 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
41 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
42 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
43 #define RAW3215_NR_CCWS	    3
44 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
45 
46 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
47 #define RAW3215_ACTIVE	    2	      /* set if the device is in use */
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_CLOSING	    32	      /* set while in close process */
52 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
53 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
54 #define RAW3215_FROZEN	    256	      /* set if 3215 is frozen for suspend */
55 
56 #define TAB_STOP_SIZE	    8	      /* tab stop size */
57 
58 /*
59  * Request types for a 3215 device
60  */
61 enum raw3215_type {
62 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
63 };
64 
65 /*
66  * Request structure for a 3215 device
67  */
68 struct raw3215_req {
69 	enum raw3215_type type;	      /* type of the request */
70 	int start, len;		      /* start index & len in output buffer */
71 	int delayable;		      /* indication to wait for more data */
72 	int residual;		      /* residual count for read request */
73 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
74 	struct raw3215_info *info;    /* pointer to main structure */
75 	struct raw3215_req *next;     /* pointer to next request */
76 } __attribute__ ((aligned(8)));
77 
78 struct raw3215_info {
79 	struct ccw_device *cdev;      /* device for tty driver */
80 	spinlock_t *lock;	      /* pointer to irq lock */
81 	int flags;		      /* state flags */
82 	char *buffer;		      /* pointer to output buffer */
83 	char *inbuf;		      /* pointer to input buffer */
84 	int head;		      /* first free byte in output buffer */
85 	int count;		      /* number of bytes in output buffer */
86 	int written;		      /* number of bytes in write requests */
87 	struct tty_struct *tty;	      /* pointer to tty structure if present */
88 	struct raw3215_req *queued_read; /* pointer to queued read requests */
89 	struct raw3215_req *queued_write;/* pointer to queued write requests */
90 	wait_queue_head_t empty_wait; /* wait queue for flushing */
91 	struct timer_list timer;      /* timer for delayed output */
92 	int line_pos;		      /* position on the line (for tabs) */
93 	char ubuffer[80];	      /* copy_from_user buffer */
94 };
95 
96 /* array of 3215 devices structures */
97 static struct raw3215_info *raw3215[NR_3215];
98 /* spinlock to protect the raw3215 array */
99 static DEFINE_SPINLOCK(raw3215_device_lock);
100 /* list of free request structures */
101 static struct raw3215_req *raw3215_freelist;
102 /* spinlock to protect free list */
103 static spinlock_t raw3215_freelist_lock;
104 
105 static struct tty_driver *tty3215_driver;
106 
107 /*
108  * Get a request structure from the free list
109  */
110 static inline struct raw3215_req *raw3215_alloc_req(void)
111 {
112 	struct raw3215_req *req;
113 	unsigned long flags;
114 
115 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
116 	req = raw3215_freelist;
117 	raw3215_freelist = req->next;
118 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
119 	return req;
120 }
121 
122 /*
123  * Put a request structure back to the free list
124  */
125 static inline void raw3215_free_req(struct raw3215_req *req)
126 {
127 	unsigned long flags;
128 
129 	if (req->type == RAW3215_FREE)
130 		return;		/* don't free a free request */
131 	req->type = RAW3215_FREE;
132 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
133 	req->next = raw3215_freelist;
134 	raw3215_freelist = req;
135 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
136 }
137 
138 /*
139  * Set up a read request that reads up to 160 byte from the 3215 device.
140  * If there is a queued read request it is used, but that shouldn't happen
141  * because a 3215 terminal won't accept a new read before the old one is
142  * completed.
143  */
144 static void raw3215_mk_read_req(struct raw3215_info *raw)
145 {
146 	struct raw3215_req *req;
147 	struct ccw1 *ccw;
148 
149 	/* there can only be ONE read request at a time */
150 	req = raw->queued_read;
151 	if (req == NULL) {
152 		/* no queued read request, use new req structure */
153 		req = raw3215_alloc_req();
154 		req->type = RAW3215_READ;
155 		req->info = raw;
156 		raw->queued_read = req;
157 	}
158 
159 	ccw = req->ccws;
160 	ccw->cmd_code = 0x0A; /* read inquiry */
161 	ccw->flags = 0x20;    /* ignore incorrect length */
162 	ccw->count = 160;
163 	ccw->cda = (__u32) __pa(raw->inbuf);
164 }
165 
166 /*
167  * Set up a write request with the information from the main structure.
168  * A ccw chain is created that writes as much as possible from the output
169  * buffer to the 3215 device. If a queued write exists it is replaced by
170  * the new, probably lengthened request.
171  */
172 static void raw3215_mk_write_req(struct raw3215_info *raw)
173 {
174 	struct raw3215_req *req;
175 	struct ccw1 *ccw;
176 	int len, count, ix, lines;
177 
178 	if (raw->count <= raw->written)
179 		return;
180 	/* check if there is a queued write request */
181 	req = raw->queued_write;
182 	if (req == NULL) {
183 		/* no queued write request, use new req structure */
184 		req = raw3215_alloc_req();
185 		req->type = RAW3215_WRITE;
186 		req->info = raw;
187 		raw->queued_write = req;
188 	} else {
189 		raw->written -= req->len;
190 	}
191 
192 	ccw = req->ccws;
193 	req->start = (raw->head - raw->count + raw->written) &
194 		     (RAW3215_BUFFER_SIZE - 1);
195 	/*
196 	 * now we have to count newlines. We can at max accept
197 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
198 	 * a restriction in VM
199 	 */
200 	lines = 0;
201 	ix = req->start;
202 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
203 		if (raw->buffer[ix] == 0x15)
204 			lines++;
205 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
206 	}
207 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
208 	if (len > RAW3215_MAX_BYTES)
209 		len = RAW3215_MAX_BYTES;
210 	req->len = len;
211 	raw->written += len;
212 
213 	/* set the indication if we should try to enlarge this request */
214 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
215 
216 	ix = req->start;
217 	while (len > 0) {
218 		if (ccw > req->ccws)
219 			ccw[-1].flags |= 0x40; /* use command chaining */
220 		ccw->cmd_code = 0x01; /* write, auto carrier return */
221 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
222 		ccw->cda =
223 			(__u32) __pa(raw->buffer + ix);
224 		count = len;
225 		if (ix + count > RAW3215_BUFFER_SIZE)
226 			count = RAW3215_BUFFER_SIZE - ix;
227 		ccw->count = count;
228 		len -= count;
229 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
230 		ccw++;
231 	}
232 	/*
233 	 * Add a NOP to the channel program. 3215 devices are purely
234 	 * emulated and its much better to avoid the channel end
235 	 * interrupt in this case.
236 	 */
237 	if (ccw > req->ccws)
238 		ccw[-1].flags |= 0x40; /* use command chaining */
239 	ccw->cmd_code = 0x03; /* NOP */
240 	ccw->flags = 0;
241 	ccw->cda = 0;
242 	ccw->count = 1;
243 }
244 
245 /*
246  * Start a read or a write request
247  */
248 static void raw3215_start_io(struct raw3215_info *raw)
249 {
250 	struct raw3215_req *req;
251 	int res;
252 
253 	req = raw->queued_read;
254 	if (req != NULL &&
255 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
256 		/* dequeue request */
257 		raw->queued_read = NULL;
258 		res = ccw_device_start(raw->cdev, req->ccws,
259 				       (unsigned long) req, 0, 0);
260 		if (res != 0) {
261 			/* do_IO failed, put request back to queue */
262 			raw->queued_read = req;
263 		} else {
264 			raw->flags |= RAW3215_WORKING;
265 		}
266 	}
267 	req = raw->queued_write;
268 	if (req != NULL &&
269 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
270 		/* dequeue request */
271 		raw->queued_write = NULL;
272 		res = ccw_device_start(raw->cdev, req->ccws,
273 				       (unsigned long) req, 0, 0);
274 		if (res != 0) {
275 			/* do_IO failed, put request back to queue */
276 			raw->queued_write = req;
277 		} else {
278 			raw->flags |= RAW3215_WORKING;
279 		}
280 	}
281 }
282 
283 /*
284  * Function to start a delayed output after RAW3215_TIMEOUT seconds
285  */
286 static void raw3215_timeout(unsigned long __data)
287 {
288 	struct raw3215_info *raw = (struct raw3215_info *) __data;
289 	unsigned long flags;
290 
291 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
292 	if (raw->flags & RAW3215_TIMER_RUNS) {
293 		del_timer(&raw->timer);
294 		raw->flags &= ~RAW3215_TIMER_RUNS;
295 		if (!(raw->flags & RAW3215_FROZEN)) {
296 			raw3215_mk_write_req(raw);
297 			raw3215_start_io(raw);
298 		}
299 	}
300 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
301 }
302 
303 /*
304  * Function to conditionally start an IO. A read is started immediately,
305  * a write is only started immediately if the flush flag is on or the
306  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
307  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
308  */
309 static inline void raw3215_try_io(struct raw3215_info *raw)
310 {
311 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FROZEN))
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 			init_timer(&raw->timer);
327 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
328 			raw->timer.data = (unsigned long) raw;
329 			raw->timer.function = raw3215_timeout;
330 			add_timer(&raw->timer);
331 			raw->flags |= RAW3215_TIMER_RUNS;
332 		}
333 	}
334 }
335 
336 /*
337  * Try to start the next IO and wake up processes waiting on the tty.
338  */
339 static void raw3215_next_io(struct raw3215_info *raw)
340 {
341 	struct tty_struct *tty;
342 
343 	raw3215_mk_write_req(raw);
344 	raw3215_try_io(raw);
345 	tty = raw->tty;
346 	if (tty != NULL &&
347 	    RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
348 	    	tty_wakeup(tty);
349 	}
350 }
351 
352 /*
353  * Interrupt routine, called from common io layer
354  */
355 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
356 			struct irb *irb)
357 {
358 	struct raw3215_info *raw;
359 	struct raw3215_req *req;
360 	struct tty_struct *tty;
361 	int cstat, dstat;
362 	int count;
363 
364 	raw = dev_get_drvdata(&cdev->dev);
365 	req = (struct raw3215_req *) intparm;
366 	cstat = irb->scsw.cmd.cstat;
367 	dstat = irb->scsw.cmd.dstat;
368 	if (cstat != 0)
369 		raw3215_next_io(raw);
370 	if (dstat & 0x01) { /* we got a unit exception */
371 		dstat &= ~0x01;	 /* we can ignore it */
372 	}
373 	switch (dstat) {
374 	case 0x80:
375 		if (cstat != 0)
376 			break;
377 		/* Attention interrupt, someone hit the enter key */
378 		raw3215_mk_read_req(raw);
379 		raw3215_next_io(raw);
380 		break;
381 	case 0x08:
382 	case 0x0C:
383 		/* Channel end interrupt. */
384 		if ((raw = req->info) == NULL)
385 			return;		     /* That shouldn't happen ... */
386 		if (req->type == RAW3215_READ) {
387 			/* store residual count, then wait for device end */
388 			req->residual = irb->scsw.cmd.count;
389 		}
390 		if (dstat == 0x08)
391 			break;
392 	case 0x04:
393 		/* Device end interrupt. */
394 		if ((raw = req->info) == NULL)
395 			return;		     /* That shouldn't happen ... */
396 		if (req->type == RAW3215_READ && raw->tty != NULL) {
397 			unsigned int cchar;
398 
399 			tty = raw->tty;
400 			count = 160 - req->residual;
401 			EBCASC(raw->inbuf, count);
402 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
403 			switch (cchar & CTRLCHAR_MASK) {
404 			case CTRLCHAR_SYSRQ:
405 				break;
406 
407 			case CTRLCHAR_CTRL:
408 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
409 				tty_flip_buffer_push(raw->tty);
410 				break;
411 
412 			case CTRLCHAR_NONE:
413 				if (count < 2 ||
414 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
415 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
416 					/* add the auto \n */
417 					raw->inbuf[count] = '\n';
418 					count++;
419 				} else
420 					count -= 2;
421 				tty_insert_flip_string(tty, raw->inbuf, count);
422 				tty_flip_buffer_push(raw->tty);
423 				break;
424 			}
425 		} else if (req->type == RAW3215_WRITE) {
426 			raw->count -= req->len;
427 			raw->written -= req->len;
428 		}
429 		raw->flags &= ~RAW3215_WORKING;
430 		raw3215_free_req(req);
431 		/* check for empty wait */
432 		if (waitqueue_active(&raw->empty_wait) &&
433 		    raw->queued_write == NULL &&
434 		    raw->queued_read == NULL) {
435 			wake_up_interruptible(&raw->empty_wait);
436 		}
437 		raw3215_next_io(raw);
438 		break;
439 	default:
440 		/* Strange interrupt, I'll do my best to clean up */
441 		if (req != NULL && req->type != RAW3215_FREE) {
442 			if (req->type == RAW3215_WRITE) {
443 				raw->count -= req->len;
444 				raw->written -= req->len;
445 			}
446 			raw->flags &= ~RAW3215_WORKING;
447 			raw3215_free_req(req);
448 		}
449 		raw3215_next_io(raw);
450 	}
451 	return;
452 }
453 
454 /*
455  * Drop the oldest line from the output buffer.
456  */
457 static void raw3215_drop_line(struct raw3215_info *raw)
458 {
459 	int ix;
460 	char ch;
461 
462 	BUG_ON(raw->written != 0);
463 	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
464 	while (raw->count > 0) {
465 		ch = raw->buffer[ix];
466 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
467 		raw->count--;
468 		if (ch == 0x15)
469 			break;
470 	}
471 	raw->head = ix;
472 }
473 
474 /*
475  * Wait until length bytes are available int the output buffer.
476  * Has to be called with the s390irq lock held. Can be called
477  * disabled.
478  */
479 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
480 {
481 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
482 		/* While console is frozen for suspend we have no other
483 		 * choice but to drop message from the buffer to make
484 		 * room for even more messages. */
485 		if (raw->flags & RAW3215_FROZEN) {
486 			raw3215_drop_line(raw);
487 			continue;
488 		}
489 		/* there might be a request pending */
490 		raw->flags |= RAW3215_FLUSHING;
491 		raw3215_mk_write_req(raw);
492 		raw3215_try_io(raw);
493 		raw->flags &= ~RAW3215_FLUSHING;
494 #ifdef CONFIG_TN3215_CONSOLE
495 		wait_cons_dev();
496 #endif
497 		/* Enough room freed up ? */
498 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
499 			break;
500 		/* there might be another cpu waiting for the lock */
501 		spin_unlock(get_ccwdev_lock(raw->cdev));
502 		udelay(100);
503 		spin_lock(get_ccwdev_lock(raw->cdev));
504 	}
505 }
506 
507 /*
508  * String write routine for 3215 devices
509  */
510 static void raw3215_write(struct raw3215_info *raw, const char *str,
511 			  unsigned int length)
512 {
513 	unsigned long flags;
514 	int c, count;
515 
516 	while (length > 0) {
517 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
518 		count = (length > RAW3215_BUFFER_SIZE) ?
519 					     RAW3215_BUFFER_SIZE : length;
520 		length -= count;
521 
522 		raw3215_make_room(raw, count);
523 
524 		/* copy string to output buffer and convert it to EBCDIC */
525 		while (1) {
526 			c = min_t(int, count,
527 				  min(RAW3215_BUFFER_SIZE - raw->count,
528 				      RAW3215_BUFFER_SIZE - raw->head));
529 			if (c <= 0)
530 				break;
531 			memcpy(raw->buffer + raw->head, str, c);
532 			ASCEBC(raw->buffer + raw->head, c);
533 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
534 			raw->count += c;
535 			raw->line_pos += c;
536 			str += c;
537 			count -= c;
538 		}
539 		if (!(raw->flags & RAW3215_WORKING)) {
540 			raw3215_mk_write_req(raw);
541 			/* start or queue request */
542 			raw3215_try_io(raw);
543 		}
544 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
545 	}
546 }
547 
548 /*
549  * Put character routine for 3215 devices
550  */
551 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
552 {
553 	unsigned long flags;
554 	unsigned int length, i;
555 
556 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
557 	if (ch == '\t') {
558 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
559 		raw->line_pos += length;
560 		ch = ' ';
561 	} else if (ch == '\n') {
562 		length = 1;
563 		raw->line_pos = 0;
564 	} else {
565 		length = 1;
566 		raw->line_pos++;
567 	}
568 	raw3215_make_room(raw, length);
569 
570 	for (i = 0; i < length; i++) {
571 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
572 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
573 		raw->count++;
574 	}
575 	if (!(raw->flags & RAW3215_WORKING)) {
576 		raw3215_mk_write_req(raw);
577 		/* start or queue request */
578 		raw3215_try_io(raw);
579 	}
580 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
581 }
582 
583 /*
584  * Flush routine, it simply sets the flush flag and tries to start
585  * pending IO.
586  */
587 static void raw3215_flush_buffer(struct raw3215_info *raw)
588 {
589 	unsigned long flags;
590 
591 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
592 	if (raw->count > 0) {
593 		raw->flags |= RAW3215_FLUSHING;
594 		raw3215_try_io(raw);
595 		raw->flags &= ~RAW3215_FLUSHING;
596 	}
597 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
598 }
599 
600 /*
601  * Fire up a 3215 device.
602  */
603 static int raw3215_startup(struct raw3215_info *raw)
604 {
605 	unsigned long flags;
606 
607 	if (raw->flags & RAW3215_ACTIVE)
608 		return 0;
609 	raw->line_pos = 0;
610 	raw->flags |= RAW3215_ACTIVE;
611 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
612 	raw3215_try_io(raw);
613 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
614 
615 	return 0;
616 }
617 
618 /*
619  * Shutdown a 3215 device.
620  */
621 static void raw3215_shutdown(struct raw3215_info *raw)
622 {
623 	DECLARE_WAITQUEUE(wait, current);
624 	unsigned long flags;
625 
626 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FIXED))
627 		return;
628 	/* Wait for outstanding requests, then free irq */
629 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
630 	if ((raw->flags & RAW3215_WORKING) ||
631 	    raw->queued_write != NULL ||
632 	    raw->queued_read != NULL) {
633 		raw->flags |= RAW3215_CLOSING;
634 		add_wait_queue(&raw->empty_wait, &wait);
635 		set_current_state(TASK_INTERRUPTIBLE);
636 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
637 		schedule();
638 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
639 		remove_wait_queue(&raw->empty_wait, &wait);
640 		set_current_state(TASK_RUNNING);
641 		raw->flags &= ~(RAW3215_ACTIVE | RAW3215_CLOSING);
642 	}
643 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
644 }
645 
646 static int raw3215_probe (struct ccw_device *cdev)
647 {
648 	struct raw3215_info *raw;
649 	int line;
650 
651 	/* Console is special. */
652 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
653 		return 0;
654 	raw = kmalloc(sizeof(struct raw3215_info) +
655 		      RAW3215_INBUF_SIZE, GFP_KERNEL|GFP_DMA);
656 	if (raw == NULL)
657 		return -ENOMEM;
658 
659 	spin_lock(&raw3215_device_lock);
660 	for (line = 0; line < NR_3215; line++) {
661 		if (!raw3215[line]) {
662 			raw3215[line] = raw;
663 			break;
664 		}
665 	}
666 	spin_unlock(&raw3215_device_lock);
667 	if (line == NR_3215) {
668 		kfree(raw);
669 		return -ENODEV;
670 	}
671 
672 	raw->cdev = cdev;
673 	raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
674 	memset(raw, 0, sizeof(struct raw3215_info));
675 	raw->buffer = kmalloc(RAW3215_BUFFER_SIZE,
676 				       GFP_KERNEL|GFP_DMA);
677 	if (raw->buffer == NULL) {
678 		spin_lock(&raw3215_device_lock);
679 		raw3215[line] = NULL;
680 		spin_unlock(&raw3215_device_lock);
681 		kfree(raw);
682 		return -ENOMEM;
683 	}
684 	init_waitqueue_head(&raw->empty_wait);
685 
686 	dev_set_drvdata(&cdev->dev, raw);
687 	cdev->handler = raw3215_irq;
688 
689 	return 0;
690 }
691 
692 static void raw3215_remove (struct ccw_device *cdev)
693 {
694 	struct raw3215_info *raw;
695 
696 	ccw_device_set_offline(cdev);
697 	raw = dev_get_drvdata(&cdev->dev);
698 	if (raw) {
699 		dev_set_drvdata(&cdev->dev, NULL);
700 		kfree(raw->buffer);
701 		kfree(raw);
702 	}
703 }
704 
705 static int raw3215_set_online (struct ccw_device *cdev)
706 {
707 	struct raw3215_info *raw;
708 
709 	raw = dev_get_drvdata(&cdev->dev);
710 	if (!raw)
711 		return -ENODEV;
712 
713 	return raw3215_startup(raw);
714 }
715 
716 static int raw3215_set_offline (struct ccw_device *cdev)
717 {
718 	struct raw3215_info *raw;
719 
720 	raw = dev_get_drvdata(&cdev->dev);
721 	if (!raw)
722 		return -ENODEV;
723 
724 	raw3215_shutdown(raw);
725 
726 	return 0;
727 }
728 
729 static int raw3215_pm_stop(struct ccw_device *cdev)
730 {
731 	struct raw3215_info *raw;
732 	unsigned long flags;
733 
734 	/* Empty the output buffer, then prevent new I/O. */
735 	raw = dev_get_drvdata(&cdev->dev);
736 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
737 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
738 	raw->flags |= RAW3215_FROZEN;
739 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
740 	return 0;
741 }
742 
743 static int raw3215_pm_start(struct ccw_device *cdev)
744 {
745 	struct raw3215_info *raw;
746 	unsigned long flags;
747 
748 	/* Allow I/O again and flush output buffer. */
749 	raw = dev_get_drvdata(&cdev->dev);
750 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
751 	raw->flags &= ~RAW3215_FROZEN;
752 	raw->flags |= RAW3215_FLUSHING;
753 	raw3215_try_io(raw);
754 	raw->flags &= ~RAW3215_FLUSHING;
755 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
756 	return 0;
757 }
758 
759 static struct ccw_device_id raw3215_id[] = {
760 	{ CCW_DEVICE(0x3215, 0) },
761 	{ /* end of list */ },
762 };
763 
764 static struct ccw_driver raw3215_ccw_driver = {
765 	.name		= "3215",
766 	.owner		= THIS_MODULE,
767 	.ids		= raw3215_id,
768 	.probe		= &raw3215_probe,
769 	.remove		= &raw3215_remove,
770 	.set_online	= &raw3215_set_online,
771 	.set_offline	= &raw3215_set_offline,
772 	.freeze		= &raw3215_pm_stop,
773 	.thaw		= &raw3215_pm_start,
774 	.restore	= &raw3215_pm_start,
775 };
776 
777 #ifdef CONFIG_TN3215_CONSOLE
778 /*
779  * Write a string to the 3215 console
780  */
781 static void con3215_write(struct console *co, const char *str,
782 			  unsigned int count)
783 {
784 	struct raw3215_info *raw;
785 	int i;
786 
787 	if (count <= 0)
788 		return;
789 	raw = raw3215[0];	/* console 3215 is the first one */
790 	while (count > 0) {
791 		for (i = 0; i < count; i++)
792 			if (str[i] == '\t' || str[i] == '\n')
793 				break;
794 		raw3215_write(raw, str, i);
795 		count -= i;
796 		str += i;
797 		if (count > 0) {
798 			raw3215_putchar(raw, *str);
799 			count--;
800 			str++;
801 		}
802 	}
803 }
804 
805 static struct tty_driver *con3215_device(struct console *c, int *index)
806 {
807 	*index = c->index;
808 	return tty3215_driver;
809 }
810 
811 /*
812  * panic() calls con3215_flush through a panic_notifier
813  * before the system enters a disabled, endless loop.
814  */
815 static void con3215_flush(void)
816 {
817 	struct raw3215_info *raw;
818 	unsigned long flags;
819 
820 	raw = raw3215[0];  /* console 3215 is the first one */
821 	if (raw->flags & RAW3215_FROZEN)
822 		/* The console is still frozen for suspend. */
823 		if (ccw_device_force_console())
824 			/* Forcing didn't work, no panic message .. */
825 			return;
826 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
827 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
828 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
829 }
830 
831 static int con3215_notify(struct notifier_block *self,
832 			  unsigned long event, void *data)
833 {
834 	con3215_flush();
835 	return NOTIFY_OK;
836 }
837 
838 static struct notifier_block on_panic_nb = {
839 	.notifier_call = con3215_notify,
840 	.priority = 0,
841 };
842 
843 static struct notifier_block on_reboot_nb = {
844 	.notifier_call = con3215_notify,
845 	.priority = 0,
846 };
847 
848 /*
849  *  The console structure for the 3215 console
850  */
851 static struct console con3215 = {
852 	.name	 = "ttyS",
853 	.write	 = con3215_write,
854 	.device	 = con3215_device,
855 	.flags	 = CON_PRINTBUFFER,
856 };
857 
858 /*
859  * 3215 console initialization code called from console_init().
860  */
861 static int __init con3215_init(void)
862 {
863 	struct ccw_device *cdev;
864 	struct raw3215_info *raw;
865 	struct raw3215_req *req;
866 	int i;
867 
868 	/* Check if 3215 is to be the console */
869 	if (!CONSOLE_IS_3215)
870 		return -ENODEV;
871 
872 	/* Set the console mode for VM */
873 	if (MACHINE_IS_VM) {
874 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
875 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
876 	}
877 
878 	/* allocate 3215 request structures */
879 	raw3215_freelist = NULL;
880 	spin_lock_init(&raw3215_freelist_lock);
881 	for (i = 0; i < NR_3215_REQ; i++) {
882 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
883 		req->next = raw3215_freelist;
884 		raw3215_freelist = req;
885 	}
886 
887 	cdev = ccw_device_probe_console();
888 	if (IS_ERR(cdev))
889 		return -ENODEV;
890 
891 	raw3215[0] = raw = (struct raw3215_info *)
892 		kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
893 	raw->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
894 	raw->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
895 	raw->cdev = cdev;
896 	dev_set_drvdata(&cdev->dev, raw);
897 	cdev->handler = raw3215_irq;
898 
899 	raw->flags |= RAW3215_FIXED;
900 	init_waitqueue_head(&raw->empty_wait);
901 
902 	/* Request the console irq */
903 	if (raw3215_startup(raw) != 0) {
904 		kfree(raw->inbuf);
905 		kfree(raw->buffer);
906 		kfree(raw);
907 		raw3215[0] = NULL;
908 		return -ENODEV;
909 	}
910 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
911 	register_reboot_notifier(&on_reboot_nb);
912 	register_console(&con3215);
913 	return 0;
914 }
915 console_initcall(con3215_init);
916 #endif
917 
918 /*
919  * tty3215_open
920  *
921  * This routine is called whenever a 3215 tty is opened.
922  */
923 static int tty3215_open(struct tty_struct *tty, struct file * filp)
924 {
925 	struct raw3215_info *raw;
926 	int retval, line;
927 
928 	line = tty->index;
929 	if ((line < 0) || (line >= NR_3215))
930 		return -ENODEV;
931 
932 	raw = raw3215[line];
933 	if (raw == NULL)
934 		return -ENODEV;
935 
936 	tty->driver_data = raw;
937 	raw->tty = tty;
938 
939 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
940 	/*
941 	 * Start up 3215 device
942 	 */
943 	retval = raw3215_startup(raw);
944 	if (retval)
945 		return retval;
946 
947 	return 0;
948 }
949 
950 /*
951  * tty3215_close()
952  *
953  * This routine is called when the 3215 tty is closed. We wait
954  * for the remaining request to be completed. Then we clean up.
955  */
956 static void tty3215_close(struct tty_struct *tty, struct file * filp)
957 {
958 	struct raw3215_info *raw;
959 
960 	raw = (struct raw3215_info *) tty->driver_data;
961 	if (raw == NULL || tty->count > 1)
962 		return;
963 	tty->closing = 1;
964 	/* Shutdown the terminal */
965 	raw3215_shutdown(raw);
966 	tty->closing = 0;
967 	raw->tty = NULL;
968 }
969 
970 /*
971  * Returns the amount of free space in the output buffer.
972  */
973 static int tty3215_write_room(struct tty_struct *tty)
974 {
975 	struct raw3215_info *raw;
976 
977 	raw = (struct raw3215_info *) tty->driver_data;
978 
979 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
980 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
981 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
982 	else
983 		return 0;
984 }
985 
986 /*
987  * String write routine for 3215 ttys
988  */
989 static int tty3215_write(struct tty_struct * tty,
990 			 const unsigned char *buf, int count)
991 {
992 	struct raw3215_info *raw;
993 
994 	if (!tty)
995 		return 0;
996 	raw = (struct raw3215_info *) tty->driver_data;
997 	raw3215_write(raw, buf, count);
998 	return count;
999 }
1000 
1001 /*
1002  * Put character routine for 3215 ttys
1003  */
1004 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1005 {
1006 	struct raw3215_info *raw;
1007 
1008 	if (!tty)
1009 		return 0;
1010 	raw = (struct raw3215_info *) tty->driver_data;
1011 	raw3215_putchar(raw, ch);
1012 	return 1;
1013 }
1014 
1015 static void tty3215_flush_chars(struct tty_struct *tty)
1016 {
1017 }
1018 
1019 /*
1020  * Returns the number of characters in the output buffer
1021  */
1022 static int tty3215_chars_in_buffer(struct tty_struct *tty)
1023 {
1024 	struct raw3215_info *raw;
1025 
1026 	raw = (struct raw3215_info *) tty->driver_data;
1027 	return raw->count;
1028 }
1029 
1030 static void tty3215_flush_buffer(struct tty_struct *tty)
1031 {
1032 	struct raw3215_info *raw;
1033 
1034 	raw = (struct raw3215_info *) tty->driver_data;
1035 	raw3215_flush_buffer(raw);
1036 	tty_wakeup(tty);
1037 }
1038 
1039 /*
1040  * Currently we don't have any io controls for 3215 ttys
1041  */
1042 static int tty3215_ioctl(struct tty_struct *tty, struct file * file,
1043 			 unsigned int cmd, unsigned long arg)
1044 {
1045 	if (tty->flags & (1 << TTY_IO_ERROR))
1046 		return -EIO;
1047 
1048 	switch (cmd) {
1049 	default:
1050 		return -ENOIOCTLCMD;
1051 	}
1052 	return 0;
1053 }
1054 
1055 /*
1056  * Disable reading from a 3215 tty
1057  */
1058 static void tty3215_throttle(struct tty_struct * tty)
1059 {
1060 	struct raw3215_info *raw;
1061 
1062 	raw = (struct raw3215_info *) tty->driver_data;
1063 	raw->flags |= RAW3215_THROTTLED;
1064 }
1065 
1066 /*
1067  * Enable reading from a 3215 tty
1068  */
1069 static void tty3215_unthrottle(struct tty_struct * tty)
1070 {
1071 	struct raw3215_info *raw;
1072 	unsigned long flags;
1073 
1074 	raw = (struct raw3215_info *) tty->driver_data;
1075 	if (raw->flags & RAW3215_THROTTLED) {
1076 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1077 		raw->flags &= ~RAW3215_THROTTLED;
1078 		raw3215_try_io(raw);
1079 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1080 	}
1081 }
1082 
1083 /*
1084  * Disable writing to a 3215 tty
1085  */
1086 static void tty3215_stop(struct tty_struct *tty)
1087 {
1088 	struct raw3215_info *raw;
1089 
1090 	raw = (struct raw3215_info *) tty->driver_data;
1091 	raw->flags |= RAW3215_STOPPED;
1092 }
1093 
1094 /*
1095  * Enable writing to a 3215 tty
1096  */
1097 static void tty3215_start(struct tty_struct *tty)
1098 {
1099 	struct raw3215_info *raw;
1100 	unsigned long flags;
1101 
1102 	raw = (struct raw3215_info *) tty->driver_data;
1103 	if (raw->flags & RAW3215_STOPPED) {
1104 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1105 		raw->flags &= ~RAW3215_STOPPED;
1106 		raw3215_try_io(raw);
1107 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1108 	}
1109 }
1110 
1111 static const struct tty_operations tty3215_ops = {
1112 	.open = tty3215_open,
1113 	.close = tty3215_close,
1114 	.write = tty3215_write,
1115 	.put_char = tty3215_put_char,
1116 	.flush_chars = tty3215_flush_chars,
1117 	.write_room = tty3215_write_room,
1118 	.chars_in_buffer = tty3215_chars_in_buffer,
1119 	.flush_buffer = tty3215_flush_buffer,
1120 	.ioctl = tty3215_ioctl,
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->owner = THIS_MODULE;
1155 	driver->driver_name = "tty3215";
1156 	driver->name = "ttyS";
1157 	driver->major = TTY_MAJOR;
1158 	driver->minor_start = 64;
1159 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1160 	driver->subtype = SYSTEM_TYPE_TTY;
1161 	driver->init_termios = tty_std_termios;
1162 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1163 	driver->init_termios.c_oflag = ONLCR | XTABS;
1164 	driver->init_termios.c_lflag = ISIG;
1165 	driver->flags = TTY_DRIVER_REAL_RAW;
1166 	tty_set_operations(driver, &tty3215_ops);
1167 	ret = tty_register_driver(driver);
1168 	if (ret) {
1169 		put_tty_driver(driver);
1170 		return ret;
1171 	}
1172 	tty3215_driver = driver;
1173 	return 0;
1174 }
1175 
1176 static void __exit tty3215_exit(void)
1177 {
1178 	tty_unregister_driver(tty3215_driver);
1179 	put_tty_driver(tty3215_driver);
1180 	ccw_driver_unregister(&raw3215_ccw_driver);
1181 }
1182 
1183 module_init(tty3215_init);
1184 module_exit(tty3215_exit);
1185