[S390] sclp_vt220: set initial terminal window size
[linux-2.6.git] / drivers / s390 / char / sclp_vt220.c
1 /*
2  * SCLP VT220 terminal driver.
3  *
4  * Copyright IBM Corp. 2003, 2009
5  *
6  * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
7  */
8
9 #include <linux/module.h>
10 #include <linux/spinlock.h>
11 #include <linux/list.h>
12 #include <linux/wait.h>
13 #include <linux/timer.h>
14 #include <linux/kernel.h>
15 #include <linux/tty.h>
16 #include <linux/tty_driver.h>
17 #include <linux/tty_flip.h>
18 #include <linux/errno.h>
19 #include <linux/mm.h>
20 #include <linux/major.h>
21 #include <linux/console.h>
22 #include <linux/kdev_t.h>
23 #include <linux/interrupt.h>
24 #include <linux/init.h>
25 #include <linux/reboot.h>
26
27 #include <asm/uaccess.h>
28 #include "sclp.h"
29
30 #define SCLP_VT220_MAJOR                TTY_MAJOR
31 #define SCLP_VT220_MINOR                65
32 #define SCLP_VT220_DRIVER_NAME          "sclp_vt220"
33 #define SCLP_VT220_DEVICE_NAME          "ttysclp"
34 #define SCLP_VT220_CONSOLE_NAME         "ttyS"
35 #define SCLP_VT220_CONSOLE_INDEX        1       /* console=ttyS1 */
36 #define SCLP_VT220_BUF_SIZE             80
37
38 /* Representation of a single write request */
39 struct sclp_vt220_request {
40         struct list_head list;
41         struct sclp_req sclp_req;
42         int retry_count;
43 };
44
45 /* VT220 SCCB */
46 struct sclp_vt220_sccb {
47         struct sccb_header header;
48         struct evbuf_header evbuf;
49 };
50
51 #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \
52                                          sizeof(struct sclp_vt220_request) - \
53                                          sizeof(struct sclp_vt220_sccb))
54
55 /* Structures and data needed to register tty driver */
56 static struct tty_driver *sclp_vt220_driver;
57
58 /* The tty_struct that the kernel associated with us */
59 static struct tty_struct *sclp_vt220_tty;
60
61 /* Lock to protect internal data from concurrent access */
62 static spinlock_t sclp_vt220_lock;
63
64 /* List of empty pages to be used as write request buffers */
65 static struct list_head sclp_vt220_empty;
66
67 /* List of pending requests */
68 static struct list_head sclp_vt220_outqueue;
69
70 /* Suspend mode flag */
71 static int sclp_vt220_suspended;
72
73 /* Flag that output queue is currently running */
74 static int sclp_vt220_queue_running;
75
76 /* Timer used for delaying write requests to merge subsequent messages into
77  * a single buffer */
78 static struct timer_list sclp_vt220_timer;
79
80 /* Pointer to current request buffer which has been partially filled but not
81  * yet sent */
82 static struct sclp_vt220_request *sclp_vt220_current_request;
83
84 /* Number of characters in current request buffer */
85 static int sclp_vt220_buffered_chars;
86
87 /* Counter controlling core driver initialization. */
88 static int __initdata sclp_vt220_init_count;
89
90 /* Flag indicating that sclp_vt220_current_request should really
91  * have been already queued but wasn't because the SCLP was processing
92  * another buffer */
93 static int sclp_vt220_flush_later;
94
95 static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf);
96 static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
97                                    enum sclp_pm_event sclp_pm_event);
98 static int __sclp_vt220_emit(struct sclp_vt220_request *request);
99 static void sclp_vt220_emit_current(void);
100
101 /* Registration structure for our interest in SCLP event buffers */
102 static struct sclp_register sclp_vt220_register = {
103         .send_mask              = EVTYP_VT220MSG_MASK,
104         .receive_mask           = EVTYP_VT220MSG_MASK,
105         .state_change_fn        = NULL,
106         .receiver_fn            = sclp_vt220_receiver_fn,
107         .pm_event_fn            = sclp_vt220_pm_event_fn,
108 };
109
110
111 /*
112  * Put provided request buffer back into queue and check emit pending
113  * buffers if necessary.
114  */
115 static void
116 sclp_vt220_process_queue(struct sclp_vt220_request *request)
117 {
118         unsigned long flags;
119         void *page;
120
121         do {
122                 /* Put buffer back to list of empty buffers */
123                 page = request->sclp_req.sccb;
124                 spin_lock_irqsave(&sclp_vt220_lock, flags);
125                 /* Move request from outqueue to empty queue */
126                 list_del(&request->list);
127                 list_add_tail((struct list_head *) page, &sclp_vt220_empty);
128                 /* Check if there is a pending buffer on the out queue. */
129                 request = NULL;
130                 if (!list_empty(&sclp_vt220_outqueue))
131                         request = list_entry(sclp_vt220_outqueue.next,
132                                              struct sclp_vt220_request, list);
133                 if (!request || sclp_vt220_suspended) {
134                         sclp_vt220_queue_running = 0;
135                         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
136                         break;
137                 }
138                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
139         } while (__sclp_vt220_emit(request));
140         if (request == NULL && sclp_vt220_flush_later)
141                 sclp_vt220_emit_current();
142         /* Check if the tty needs a wake up call */
143         if (sclp_vt220_tty != NULL) {
144                 tty_wakeup(sclp_vt220_tty);
145         }
146 }
147
148 #define SCLP_BUFFER_MAX_RETRY           1
149
150 /*
151  * Callback through which the result of a write request is reported by the
152  * SCLP.
153  */
154 static void
155 sclp_vt220_callback(struct sclp_req *request, void *data)
156 {
157         struct sclp_vt220_request *vt220_request;
158         struct sclp_vt220_sccb *sccb;
159
160         vt220_request = (struct sclp_vt220_request *) data;
161         if (request->status == SCLP_REQ_FAILED) {
162                 sclp_vt220_process_queue(vt220_request);
163                 return;
164         }
165         sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb;
166
167         /* Check SCLP response code and choose suitable action  */
168         switch (sccb->header.response_code) {
169         case 0x0020 :
170                 break;
171
172         case 0x05f0: /* Target resource in improper state */
173                 break;
174
175         case 0x0340: /* Contained SCLP equipment check */
176                 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
177                         break;
178                 /* Remove processed buffers and requeue rest */
179                 if (sclp_remove_processed((struct sccb_header *) sccb) > 0) {
180                         /* Not all buffers were processed */
181                         sccb->header.response_code = 0x0000;
182                         vt220_request->sclp_req.status = SCLP_REQ_FILLED;
183                         if (sclp_add_request(request) == 0)
184                                 return;
185                 }
186                 break;
187
188         case 0x0040: /* SCLP equipment check */
189                 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
190                         break;
191                 sccb->header.response_code = 0x0000;
192                 vt220_request->sclp_req.status = SCLP_REQ_FILLED;
193                 if (sclp_add_request(request) == 0)
194                         return;
195                 break;
196
197         default:
198                 break;
199         }
200         sclp_vt220_process_queue(vt220_request);
201 }
202
203 /*
204  * Emit vt220 request buffer to SCLP. Return zero on success, non-zero
205  * otherwise.
206  */
207 static int
208 __sclp_vt220_emit(struct sclp_vt220_request *request)
209 {
210         if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) {
211                 request->sclp_req.status = SCLP_REQ_FAILED;
212                 return -EIO;
213         }
214         request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA;
215         request->sclp_req.status = SCLP_REQ_FILLED;
216         request->sclp_req.callback = sclp_vt220_callback;
217         request->sclp_req.callback_data = (void *) request;
218
219         return sclp_add_request(&request->sclp_req);
220 }
221
222 /*
223  * Queue and emit current request.
224  */
225 static void
226 sclp_vt220_emit_current(void)
227 {
228         unsigned long flags;
229         struct sclp_vt220_request *request;
230         struct sclp_vt220_sccb *sccb;
231
232         spin_lock_irqsave(&sclp_vt220_lock, flags);
233         if (sclp_vt220_current_request) {
234                 sccb = (struct sclp_vt220_sccb *) 
235                                 sclp_vt220_current_request->sclp_req.sccb;
236                 /* Only emit buffers with content */
237                 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) {
238                         list_add_tail(&sclp_vt220_current_request->list,
239                                       &sclp_vt220_outqueue);
240                         sclp_vt220_current_request = NULL;
241                         if (timer_pending(&sclp_vt220_timer))
242                                 del_timer(&sclp_vt220_timer);
243                 }
244                 sclp_vt220_flush_later = 0;
245         }
246         if (sclp_vt220_queue_running || sclp_vt220_suspended)
247                 goto out_unlock;
248         if (list_empty(&sclp_vt220_outqueue))
249                 goto out_unlock;
250         request = list_first_entry(&sclp_vt220_outqueue,
251                                    struct sclp_vt220_request, list);
252         sclp_vt220_queue_running = 1;
253         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
254
255         if (__sclp_vt220_emit(request))
256                 sclp_vt220_process_queue(request);
257         return;
258 out_unlock:
259         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
260 }
261
262 #define SCLP_NORMAL_WRITE       0x00
263
264 /*
265  * Helper function to initialize a page with the sclp request structure.
266  */
267 static struct sclp_vt220_request *
268 sclp_vt220_initialize_page(void *page)
269 {
270         struct sclp_vt220_request *request;
271         struct sclp_vt220_sccb *sccb;
272
273         /* Place request structure at end of page */
274         request = ((struct sclp_vt220_request *)
275                         ((addr_t) page + PAGE_SIZE)) - 1;
276         request->retry_count = 0;
277         request->sclp_req.sccb = page;
278         /* SCCB goes at start of page */
279         sccb = (struct sclp_vt220_sccb *) page;
280         memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb));
281         sccb->header.length = sizeof(struct sclp_vt220_sccb);
282         sccb->header.function_code = SCLP_NORMAL_WRITE;
283         sccb->header.response_code = 0x0000;
284         sccb->evbuf.type = EVTYP_VT220MSG;
285         sccb->evbuf.length = sizeof(struct evbuf_header);
286
287         return request;
288 }
289
290 static inline unsigned int
291 sclp_vt220_space_left(struct sclp_vt220_request *request)
292 {
293         struct sclp_vt220_sccb *sccb;
294         sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
295         return PAGE_SIZE - sizeof(struct sclp_vt220_request) -
296                sccb->header.length;
297 }
298
299 static inline unsigned int
300 sclp_vt220_chars_stored(struct sclp_vt220_request *request)
301 {
302         struct sclp_vt220_sccb *sccb;
303         sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
304         return sccb->evbuf.length - sizeof(struct evbuf_header);
305 }
306
307 /*
308  * Add msg to buffer associated with request. Return the number of characters
309  * added.
310  */
311 static int
312 sclp_vt220_add_msg(struct sclp_vt220_request *request,
313                    const unsigned char *msg, int count, int convertlf)
314 {
315         struct sclp_vt220_sccb *sccb;
316         void *buffer;
317         unsigned char c;
318         int from;
319         int to;
320
321         if (count > sclp_vt220_space_left(request))
322                 count = sclp_vt220_space_left(request);
323         if (count <= 0)
324                 return 0;
325
326         sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
327         buffer = (void *) ((addr_t) sccb + sccb->header.length);
328
329         if (convertlf) {
330                 /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/
331                 for (from=0, to=0;
332                      (from < count) && (to < sclp_vt220_space_left(request));
333                      from++) {
334                         /* Retrieve character */
335                         c = msg[from];
336                         /* Perform conversion */
337                         if (c == 0x0a) {
338                                 if (to + 1 < sclp_vt220_space_left(request)) {
339                                         ((unsigned char *) buffer)[to++] = c;
340                                         ((unsigned char *) buffer)[to++] = 0x0d;
341                                 } else
342                                         break;
343
344                         } else
345                                 ((unsigned char *) buffer)[to++] = c;
346                 }
347                 sccb->header.length += to;
348                 sccb->evbuf.length += to;
349                 return from;
350         } else {
351                 memcpy(buffer, (const void *) msg, count);
352                 sccb->header.length += count;
353                 sccb->evbuf.length += count;
354                 return count;
355         }
356 }
357
358 /*
359  * Emit buffer after having waited long enough for more data to arrive.
360  */
361 static void
362 sclp_vt220_timeout(unsigned long data)
363 {
364         sclp_vt220_emit_current();
365 }
366
367 #define BUFFER_MAX_DELAY        HZ/20
368
369 /* 
370  * Internal implementation of the write function. Write COUNT bytes of data
371  * from memory at BUF
372  * to the SCLP interface. In case that the data does not fit into the current
373  * write buffer, emit the current one and allocate a new one. If there are no
374  * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
375  * is non-zero, the buffer will be scheduled for emitting after a timeout -
376  * otherwise the user has to explicitly call the flush function.
377  * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message
378  * buffer should be converted to 0x0a 0x0d. After completion, return the number
379  * of bytes written.
380  */
381 static int
382 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
383                    int convertlf, int may_fail)
384 {
385         unsigned long flags;
386         void *page;
387         int written;
388         int overall_written;
389
390         if (count <= 0)
391                 return 0;
392         overall_written = 0;
393         spin_lock_irqsave(&sclp_vt220_lock, flags);
394         do {
395                 /* Create an sclp output buffer if none exists yet */
396                 if (sclp_vt220_current_request == NULL) {
397                         while (list_empty(&sclp_vt220_empty)) {
398                                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
399                                 if (may_fail || sclp_vt220_suspended)
400                                         goto out;
401                                 else
402                                         sclp_sync_wait();
403                                 spin_lock_irqsave(&sclp_vt220_lock, flags);
404                         }
405                         page = (void *) sclp_vt220_empty.next;
406                         list_del((struct list_head *) page);
407                         sclp_vt220_current_request =
408                                 sclp_vt220_initialize_page(page);
409                 }
410                 /* Try to write the string to the current request buffer */
411                 written = sclp_vt220_add_msg(sclp_vt220_current_request,
412                                              buf, count, convertlf);
413                 overall_written += written;
414                 if (written == count)
415                         break;
416                 /*
417                  * Not all characters could be written to the current
418                  * output buffer. Emit the buffer, create a new buffer
419                  * and then output the rest of the string.
420                  */
421                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
422                 sclp_vt220_emit_current();
423                 spin_lock_irqsave(&sclp_vt220_lock, flags);
424                 buf += written;
425                 count -= written;
426         } while (count > 0);
427         /* Setup timer to output current console buffer after some time */
428         if (sclp_vt220_current_request != NULL &&
429             !timer_pending(&sclp_vt220_timer) && do_schedule) {
430                 sclp_vt220_timer.function = sclp_vt220_timeout;
431                 sclp_vt220_timer.data = 0UL;
432                 sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY;
433                 add_timer(&sclp_vt220_timer);
434         }
435         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
436 out:
437         return overall_written;
438 }
439
440 /*
441  * This routine is called by the kernel to write a series of
442  * characters to the tty device.  The characters may come from
443  * user space or kernel space.  This routine will return the
444  * number of characters actually accepted for writing.
445  */
446 static int
447 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
448 {
449         return __sclp_vt220_write(buf, count, 1, 0, 1);
450 }
451
452 #define SCLP_VT220_SESSION_ENDED        0x01
453 #define SCLP_VT220_SESSION_STARTED      0x80
454 #define SCLP_VT220_SESSION_DATA         0x00
455
456 /*
457  * Called by the SCLP to report incoming event buffers.
458  */
459 static void
460 sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
461 {
462         char *buffer;
463         unsigned int count;
464
465         /* Ignore input if device is not open */
466         if (sclp_vt220_tty == NULL)
467                 return;
468
469         buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header));
470         count = evbuf->length - sizeof(struct evbuf_header);
471
472         switch (*buffer) {
473         case SCLP_VT220_SESSION_ENDED:
474         case SCLP_VT220_SESSION_STARTED:
475                 break;
476         case SCLP_VT220_SESSION_DATA:
477                 /* Send input to line discipline */
478                 buffer++;
479                 count--;
480                 tty_insert_flip_string(sclp_vt220_tty, buffer, count);
481                 tty_flip_buffer_push(sclp_vt220_tty);
482                 break;
483         }
484 }
485
486 /*
487  * This routine is called when a particular tty device is opened.
488  */
489 static int
490 sclp_vt220_open(struct tty_struct *tty, struct file *filp)
491 {
492         if (tty->count == 1) {
493                 sclp_vt220_tty = tty;
494                 tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
495                 if (tty->driver_data == NULL)
496                         return -ENOMEM;
497                 tty->low_latency = 0;
498                 if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
499                         tty->winsize.ws_row = 24;
500                         tty->winsize.ws_col = 80;
501                 }
502         }
503         return 0;
504 }
505
506 /*
507  * This routine is called when a particular tty device is closed.
508  */
509 static void
510 sclp_vt220_close(struct tty_struct *tty, struct file *filp)
511 {
512         if (tty->count == 1) {
513                 sclp_vt220_tty = NULL;
514                 kfree(tty->driver_data);
515                 tty->driver_data = NULL;
516         }
517 }
518
519 /*
520  * This routine is called by the kernel to write a single
521  * character to the tty device.  If the kernel uses this routine,
522  * it must call the flush_chars() routine (if defined) when it is
523  * done stuffing characters into the driver.
524  */
525 static int
526 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
527 {
528         return __sclp_vt220_write(&ch, 1, 0, 0, 1);
529 }
530
531 /*
532  * This routine is called by the kernel after it has written a
533  * series of characters to the tty device using put_char().  
534  */
535 static void
536 sclp_vt220_flush_chars(struct tty_struct *tty)
537 {
538         if (!sclp_vt220_queue_running)
539                 sclp_vt220_emit_current();
540         else
541                 sclp_vt220_flush_later = 1;
542 }
543
544 /*
545  * This routine returns the numbers of characters the tty driver
546  * will accept for queuing to be written.  This number is subject
547  * to change as output buffers get emptied, or if the output flow
548  * control is acted.
549  */
550 static int
551 sclp_vt220_write_room(struct tty_struct *tty)
552 {
553         unsigned long flags;
554         struct list_head *l;
555         int count;
556
557         spin_lock_irqsave(&sclp_vt220_lock, flags);
558         count = 0;
559         if (sclp_vt220_current_request != NULL)
560                 count = sclp_vt220_space_left(sclp_vt220_current_request);
561         list_for_each(l, &sclp_vt220_empty)
562                 count += SCLP_VT220_MAX_CHARS_PER_BUFFER;
563         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
564         return count;
565 }
566
567 /*
568  * Return number of buffered chars.
569  */
570 static int
571 sclp_vt220_chars_in_buffer(struct tty_struct *tty)
572 {
573         unsigned long flags;
574         struct list_head *l;
575         struct sclp_vt220_request *r;
576         int count;
577
578         spin_lock_irqsave(&sclp_vt220_lock, flags);
579         count = 0;
580         if (sclp_vt220_current_request != NULL)
581                 count = sclp_vt220_chars_stored(sclp_vt220_current_request);
582         list_for_each(l, &sclp_vt220_outqueue) {
583                 r = list_entry(l, struct sclp_vt220_request, list);
584                 count += sclp_vt220_chars_stored(r);
585         }
586         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
587         return count;
588 }
589
590 /*
591  * Pass on all buffers to the hardware. Return only when there are no more
592  * buffers pending.
593  */
594 static void
595 sclp_vt220_flush_buffer(struct tty_struct *tty)
596 {
597         sclp_vt220_emit_current();
598 }
599
600 /* Release allocated pages. */
601 static void __init __sclp_vt220_free_pages(void)
602 {
603         struct list_head *page, *p;
604
605         list_for_each_safe(page, p, &sclp_vt220_empty) {
606                 list_del(page);
607                 free_page((unsigned long) page);
608         }
609 }
610
611 /* Release memory and unregister from sclp core. Controlled by init counting -
612  * only the last invoker will actually perform these actions. */
613 static void __init __sclp_vt220_cleanup(void)
614 {
615         sclp_vt220_init_count--;
616         if (sclp_vt220_init_count != 0)
617                 return;
618         sclp_unregister(&sclp_vt220_register);
619         __sclp_vt220_free_pages();
620 }
621
622 /* Allocate buffer pages and register with sclp core. Controlled by init
623  * counting - only the first invoker will actually perform these actions. */
624 static int __init __sclp_vt220_init(int num_pages)
625 {
626         void *page;
627         int i;
628         int rc;
629
630         sclp_vt220_init_count++;
631         if (sclp_vt220_init_count != 1)
632                 return 0;
633         spin_lock_init(&sclp_vt220_lock);
634         INIT_LIST_HEAD(&sclp_vt220_empty);
635         INIT_LIST_HEAD(&sclp_vt220_outqueue);
636         init_timer(&sclp_vt220_timer);
637         sclp_vt220_current_request = NULL;
638         sclp_vt220_buffered_chars = 0;
639         sclp_vt220_tty = NULL;
640         sclp_vt220_flush_later = 0;
641
642         /* Allocate pages for output buffering */
643         rc = -ENOMEM;
644         for (i = 0; i < num_pages; i++) {
645                 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
646                 if (!page)
647                         goto out;
648                 list_add_tail(page, &sclp_vt220_empty);
649         }
650         rc = sclp_register(&sclp_vt220_register);
651 out:
652         if (rc) {
653                 __sclp_vt220_free_pages();
654                 sclp_vt220_init_count--;
655         }
656         return rc;
657 }
658
659 static const struct tty_operations sclp_vt220_ops = {
660         .open = sclp_vt220_open,
661         .close = sclp_vt220_close,
662         .write = sclp_vt220_write,
663         .put_char = sclp_vt220_put_char,
664         .flush_chars = sclp_vt220_flush_chars,
665         .write_room = sclp_vt220_write_room,
666         .chars_in_buffer = sclp_vt220_chars_in_buffer,
667         .flush_buffer = sclp_vt220_flush_buffer,
668 };
669
670 /*
671  * Register driver with SCLP and Linux and initialize internal tty structures.
672  */
673 static int __init sclp_vt220_tty_init(void)
674 {
675         struct tty_driver *driver;
676         int rc;
677
678         /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
679          * symmetry between VM and LPAR systems regarding ttyS1. */
680         driver = alloc_tty_driver(1);
681         if (!driver)
682                 return -ENOMEM;
683         rc = __sclp_vt220_init(MAX_KMEM_PAGES);
684         if (rc)
685                 goto out_driver;
686
687         driver->owner = THIS_MODULE;
688         driver->driver_name = SCLP_VT220_DRIVER_NAME;
689         driver->name = SCLP_VT220_DEVICE_NAME;
690         driver->major = SCLP_VT220_MAJOR;
691         driver->minor_start = SCLP_VT220_MINOR;
692         driver->type = TTY_DRIVER_TYPE_SYSTEM;
693         driver->subtype = SYSTEM_TYPE_TTY;
694         driver->init_termios = tty_std_termios;
695         driver->flags = TTY_DRIVER_REAL_RAW;
696         tty_set_operations(driver, &sclp_vt220_ops);
697
698         rc = tty_register_driver(driver);
699         if (rc)
700                 goto out_init;
701         sclp_vt220_driver = driver;
702         return 0;
703
704 out_init:
705         __sclp_vt220_cleanup();
706 out_driver:
707         put_tty_driver(driver);
708         return rc;
709 }
710 __initcall(sclp_vt220_tty_init);
711
712 static void __sclp_vt220_flush_buffer(void)
713 {
714         unsigned long flags;
715
716         sclp_vt220_emit_current();
717         spin_lock_irqsave(&sclp_vt220_lock, flags);
718         if (timer_pending(&sclp_vt220_timer))
719                 del_timer(&sclp_vt220_timer);
720         while (sclp_vt220_queue_running) {
721                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
722                 sclp_sync_wait();
723                 spin_lock_irqsave(&sclp_vt220_lock, flags);
724         }
725         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
726 }
727
728 /*
729  * Resume console: If there are cached messages, emit them.
730  */
731 static void sclp_vt220_resume(void)
732 {
733         unsigned long flags;
734
735         spin_lock_irqsave(&sclp_vt220_lock, flags);
736         sclp_vt220_suspended = 0;
737         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
738         sclp_vt220_emit_current();
739 }
740
741 /*
742  * Suspend console: Set suspend flag and flush console
743  */
744 static void sclp_vt220_suspend(void)
745 {
746         unsigned long flags;
747
748         spin_lock_irqsave(&sclp_vt220_lock, flags);
749         sclp_vt220_suspended = 1;
750         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
751         __sclp_vt220_flush_buffer();
752 }
753
754 static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
755                                    enum sclp_pm_event sclp_pm_event)
756 {
757         switch (sclp_pm_event) {
758         case SCLP_PM_EVENT_FREEZE:
759                 sclp_vt220_suspend();
760                 break;
761         case SCLP_PM_EVENT_RESTORE:
762         case SCLP_PM_EVENT_THAW:
763                 sclp_vt220_resume();
764                 break;
765         }
766 }
767
768 #ifdef CONFIG_SCLP_VT220_CONSOLE
769
770 static void
771 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
772 {
773         __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0);
774 }
775
776 static struct tty_driver *
777 sclp_vt220_con_device(struct console *c, int *index)
778 {
779         *index = 0;
780         return sclp_vt220_driver;
781 }
782
783 static int
784 sclp_vt220_notify(struct notifier_block *self,
785                           unsigned long event, void *data)
786 {
787         __sclp_vt220_flush_buffer();
788         return NOTIFY_OK;
789 }
790
791 static struct notifier_block on_panic_nb = {
792         .notifier_call = sclp_vt220_notify,
793         .priority = 1,
794 };
795
796 static struct notifier_block on_reboot_nb = {
797         .notifier_call = sclp_vt220_notify,
798         .priority = 1,
799 };
800
801 /* Structure needed to register with printk */
802 static struct console sclp_vt220_console =
803 {
804         .name = SCLP_VT220_CONSOLE_NAME,
805         .write = sclp_vt220_con_write,
806         .device = sclp_vt220_con_device,
807         .flags = CON_PRINTBUFFER,
808         .index = SCLP_VT220_CONSOLE_INDEX
809 };
810
811 static int __init
812 sclp_vt220_con_init(void)
813 {
814         int rc;
815
816         if (!CONSOLE_IS_SCLP)
817                 return 0;
818         rc = __sclp_vt220_init(MAX_CONSOLE_PAGES);
819         if (rc)
820                 return rc;
821         /* Attach linux console */
822         atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
823         register_reboot_notifier(&on_reboot_nb);
824         register_console(&sclp_vt220_console);
825         return 0;
826 }
827
828 console_initcall(sclp_vt220_con_init);
829 #endif /* CONFIG_SCLP_VT220_CONSOLE */
830