Linux 4.19.133
[linux/fpc-iii.git] / drivers / s390 / char / sclp_vt220.c
blob3f9a6ef650fac41c938cc797ced3a62d1b10fa81
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SCLP VT220 terminal driver.
5 * Copyright IBM Corp. 2003, 2009
7 * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
8 */
10 #include <linux/module.h>
11 #include <linux/spinlock.h>
12 #include <linux/list.h>
13 #include <linux/wait.h>
14 #include <linux/timer.h>
15 #include <linux/kernel.h>
16 #include <linux/sysrq.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/errno.h>
21 #include <linux/mm.h>
22 #include <linux/major.h>
23 #include <linux/console.h>
24 #include <linux/kdev_t.h>
25 #include <linux/interrupt.h>
26 #include <linux/init.h>
27 #include <linux/reboot.h>
28 #include <linux/slab.h>
30 #include <linux/uaccess.h>
31 #include "sclp.h"
32 #include "ctrlchar.h"
34 #define SCLP_VT220_MAJOR TTY_MAJOR
35 #define SCLP_VT220_MINOR 65
36 #define SCLP_VT220_DRIVER_NAME "sclp_vt220"
37 #define SCLP_VT220_DEVICE_NAME "ttysclp"
38 #define SCLP_VT220_CONSOLE_NAME "ttyS"
39 #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */
41 /* Representation of a single write request */
42 struct sclp_vt220_request {
43 struct list_head list;
44 struct sclp_req sclp_req;
45 int retry_count;
48 /* VT220 SCCB */
49 struct sclp_vt220_sccb {
50 struct sccb_header header;
51 struct evbuf_header evbuf;
54 #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \
55 sizeof(struct sclp_vt220_request) - \
56 sizeof(struct sclp_vt220_sccb))
58 /* Structures and data needed to register tty driver */
59 static struct tty_driver *sclp_vt220_driver;
61 static struct tty_port sclp_vt220_port;
63 /* Lock to protect internal data from concurrent access */
64 static spinlock_t sclp_vt220_lock;
66 /* List of empty pages to be used as write request buffers */
67 static struct list_head sclp_vt220_empty;
69 /* List of pending requests */
70 static struct list_head sclp_vt220_outqueue;
72 /* Suspend mode flag */
73 static int sclp_vt220_suspended;
75 /* Flag that output queue is currently running */
76 static int sclp_vt220_queue_running;
78 /* Timer used for delaying write requests to merge subsequent messages into
79 * a single buffer */
80 static struct timer_list sclp_vt220_timer;
82 /* Pointer to current request buffer which has been partially filled but not
83 * yet sent */
84 static struct sclp_vt220_request *sclp_vt220_current_request;
86 /* Number of characters in current request buffer */
87 static int sclp_vt220_buffered_chars;
89 /* Counter controlling core driver initialization. */
90 static int __initdata sclp_vt220_init_count;
92 /* Flag indicating that sclp_vt220_current_request should really
93 * have been already queued but wasn't because the SCLP was processing
94 * another buffer */
95 static int sclp_vt220_flush_later;
97 static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf);
98 static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
99 enum sclp_pm_event sclp_pm_event);
100 static int __sclp_vt220_emit(struct sclp_vt220_request *request);
101 static void sclp_vt220_emit_current(void);
103 /* Registration structure for SCLP output event buffers */
104 static struct sclp_register sclp_vt220_register = {
105 .send_mask = EVTYP_VT220MSG_MASK,
106 .pm_event_fn = sclp_vt220_pm_event_fn,
109 /* Registration structure for SCLP input event buffers */
110 static struct sclp_register sclp_vt220_register_input = {
111 .receive_mask = EVTYP_VT220MSG_MASK,
112 .receiver_fn = sclp_vt220_receiver_fn,
117 * Put provided request buffer back into queue and check emit pending
118 * buffers if necessary.
120 static void
121 sclp_vt220_process_queue(struct sclp_vt220_request *request)
123 unsigned long flags;
124 void *page;
126 do {
127 /* Put buffer back to list of empty buffers */
128 page = request->sclp_req.sccb;
129 spin_lock_irqsave(&sclp_vt220_lock, flags);
130 /* Move request from outqueue to empty queue */
131 list_del(&request->list);
132 list_add_tail((struct list_head *) page, &sclp_vt220_empty);
133 /* Check if there is a pending buffer on the out queue. */
134 request = NULL;
135 if (!list_empty(&sclp_vt220_outqueue))
136 request = list_entry(sclp_vt220_outqueue.next,
137 struct sclp_vt220_request, list);
138 if (!request || sclp_vt220_suspended) {
139 sclp_vt220_queue_running = 0;
140 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
141 break;
143 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
144 } while (__sclp_vt220_emit(request));
145 if (request == NULL && sclp_vt220_flush_later)
146 sclp_vt220_emit_current();
147 tty_port_tty_wakeup(&sclp_vt220_port);
150 #define SCLP_BUFFER_MAX_RETRY 1
153 * Callback through which the result of a write request is reported by the
154 * SCLP.
156 static void
157 sclp_vt220_callback(struct sclp_req *request, void *data)
159 struct sclp_vt220_request *vt220_request;
160 struct sclp_vt220_sccb *sccb;
162 vt220_request = (struct sclp_vt220_request *) data;
163 if (request->status == SCLP_REQ_FAILED) {
164 sclp_vt220_process_queue(vt220_request);
165 return;
167 sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb;
169 /* Check SCLP response code and choose suitable action */
170 switch (sccb->header.response_code) {
171 case 0x0020 :
172 break;
174 case 0x05f0: /* Target resource in improper state */
175 break;
177 case 0x0340: /* Contained SCLP equipment check */
178 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
179 break;
180 /* Remove processed buffers and requeue rest */
181 if (sclp_remove_processed((struct sccb_header *) sccb) > 0) {
182 /* Not all buffers were processed */
183 sccb->header.response_code = 0x0000;
184 vt220_request->sclp_req.status = SCLP_REQ_FILLED;
185 if (sclp_add_request(request) == 0)
186 return;
188 break;
190 case 0x0040: /* SCLP equipment check */
191 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
192 break;
193 sccb->header.response_code = 0x0000;
194 vt220_request->sclp_req.status = SCLP_REQ_FILLED;
195 if (sclp_add_request(request) == 0)
196 return;
197 break;
199 default:
200 break;
202 sclp_vt220_process_queue(vt220_request);
206 * Emit vt220 request buffer to SCLP. Return zero on success, non-zero
207 * otherwise.
209 static int
210 __sclp_vt220_emit(struct sclp_vt220_request *request)
212 request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA;
213 request->sclp_req.status = SCLP_REQ_FILLED;
214 request->sclp_req.callback = sclp_vt220_callback;
215 request->sclp_req.callback_data = (void *) request;
217 return sclp_add_request(&request->sclp_req);
221 * Queue and emit current request.
223 static void
224 sclp_vt220_emit_current(void)
226 unsigned long flags;
227 struct sclp_vt220_request *request;
228 struct sclp_vt220_sccb *sccb;
230 spin_lock_irqsave(&sclp_vt220_lock, flags);
231 if (sclp_vt220_current_request) {
232 sccb = (struct sclp_vt220_sccb *)
233 sclp_vt220_current_request->sclp_req.sccb;
234 /* Only emit buffers with content */
235 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) {
236 list_add_tail(&sclp_vt220_current_request->list,
237 &sclp_vt220_outqueue);
238 sclp_vt220_current_request = NULL;
239 if (timer_pending(&sclp_vt220_timer))
240 del_timer(&sclp_vt220_timer);
242 sclp_vt220_flush_later = 0;
244 if (sclp_vt220_queue_running || sclp_vt220_suspended)
245 goto out_unlock;
246 if (list_empty(&sclp_vt220_outqueue))
247 goto out_unlock;
248 request = list_first_entry(&sclp_vt220_outqueue,
249 struct sclp_vt220_request, list);
250 sclp_vt220_queue_running = 1;
251 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
253 if (__sclp_vt220_emit(request))
254 sclp_vt220_process_queue(request);
255 return;
256 out_unlock:
257 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
260 #define SCLP_NORMAL_WRITE 0x00
263 * Helper function to initialize a page with the sclp request structure.
265 static struct sclp_vt220_request *
266 sclp_vt220_initialize_page(void *page)
268 struct sclp_vt220_request *request;
269 struct sclp_vt220_sccb *sccb;
271 /* Place request structure at end of page */
272 request = ((struct sclp_vt220_request *)
273 ((addr_t) page + PAGE_SIZE)) - 1;
274 request->retry_count = 0;
275 request->sclp_req.sccb = page;
276 /* SCCB goes at start of page */
277 sccb = (struct sclp_vt220_sccb *) page;
278 memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb));
279 sccb->header.length = sizeof(struct sclp_vt220_sccb);
280 sccb->header.function_code = SCLP_NORMAL_WRITE;
281 sccb->header.response_code = 0x0000;
282 sccb->evbuf.type = EVTYP_VT220MSG;
283 sccb->evbuf.length = sizeof(struct evbuf_header);
285 return request;
288 static inline unsigned int
289 sclp_vt220_space_left(struct sclp_vt220_request *request)
291 struct sclp_vt220_sccb *sccb;
292 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
293 return PAGE_SIZE - sizeof(struct sclp_vt220_request) -
294 sccb->header.length;
297 static inline unsigned int
298 sclp_vt220_chars_stored(struct sclp_vt220_request *request)
300 struct sclp_vt220_sccb *sccb;
301 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
302 return sccb->evbuf.length - sizeof(struct evbuf_header);
306 * Add msg to buffer associated with request. Return the number of characters
307 * added.
309 static int
310 sclp_vt220_add_msg(struct sclp_vt220_request *request,
311 const unsigned char *msg, int count, int convertlf)
313 struct sclp_vt220_sccb *sccb;
314 void *buffer;
315 unsigned char c;
316 int from;
317 int to;
319 if (count > sclp_vt220_space_left(request))
320 count = sclp_vt220_space_left(request);
321 if (count <= 0)
322 return 0;
324 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
325 buffer = (void *) ((addr_t) sccb + sccb->header.length);
327 if (convertlf) {
328 /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/
329 for (from=0, to=0;
330 (from < count) && (to < sclp_vt220_space_left(request));
331 from++) {
332 /* Retrieve character */
333 c = msg[from];
334 /* Perform conversion */
335 if (c == 0x0a) {
336 if (to + 1 < sclp_vt220_space_left(request)) {
337 ((unsigned char *) buffer)[to++] = c;
338 ((unsigned char *) buffer)[to++] = 0x0d;
339 } else
340 break;
342 } else
343 ((unsigned char *) buffer)[to++] = c;
345 sccb->header.length += to;
346 sccb->evbuf.length += to;
347 return from;
348 } else {
349 memcpy(buffer, (const void *) msg, count);
350 sccb->header.length += count;
351 sccb->evbuf.length += count;
352 return count;
357 * Emit buffer after having waited long enough for more data to arrive.
359 static void
360 sclp_vt220_timeout(struct timer_list *unused)
362 sclp_vt220_emit_current();
365 #define BUFFER_MAX_DELAY HZ/20
368 * Drop oldest console buffer if sclp_con_drop is set
370 static int
371 sclp_vt220_drop_buffer(void)
373 struct list_head *list;
374 struct sclp_vt220_request *request;
375 void *page;
377 if (!sclp_console_drop)
378 return 0;
379 list = sclp_vt220_outqueue.next;
380 if (sclp_vt220_queue_running)
381 /* The first element is in I/O */
382 list = list->next;
383 if (list == &sclp_vt220_outqueue)
384 return 0;
385 list_del(list);
386 request = list_entry(list, struct sclp_vt220_request, list);
387 page = request->sclp_req.sccb;
388 list_add_tail((struct list_head *) page, &sclp_vt220_empty);
389 return 1;
393 * Internal implementation of the write function. Write COUNT bytes of data
394 * from memory at BUF
395 * to the SCLP interface. In case that the data does not fit into the current
396 * write buffer, emit the current one and allocate a new one. If there are no
397 * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
398 * is non-zero, the buffer will be scheduled for emitting after a timeout -
399 * otherwise the user has to explicitly call the flush function.
400 * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message
401 * buffer should be converted to 0x0a 0x0d. After completion, return the number
402 * of bytes written.
404 static int
405 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
406 int convertlf, int may_fail)
408 unsigned long flags;
409 void *page;
410 int written;
411 int overall_written;
413 if (count <= 0)
414 return 0;
415 overall_written = 0;
416 spin_lock_irqsave(&sclp_vt220_lock, flags);
417 do {
418 /* Create an sclp output buffer if none exists yet */
419 if (sclp_vt220_current_request == NULL) {
420 if (list_empty(&sclp_vt220_empty))
421 sclp_console_full++;
422 while (list_empty(&sclp_vt220_empty)) {
423 if (may_fail || sclp_vt220_suspended)
424 goto out;
425 if (sclp_vt220_drop_buffer())
426 break;
427 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
429 sclp_sync_wait();
430 spin_lock_irqsave(&sclp_vt220_lock, flags);
432 page = (void *) sclp_vt220_empty.next;
433 list_del((struct list_head *) page);
434 sclp_vt220_current_request =
435 sclp_vt220_initialize_page(page);
437 /* Try to write the string to the current request buffer */
438 written = sclp_vt220_add_msg(sclp_vt220_current_request,
439 buf, count, convertlf);
440 overall_written += written;
441 if (written == count)
442 break;
444 * Not all characters could be written to the current
445 * output buffer. Emit the buffer, create a new buffer
446 * and then output the rest of the string.
448 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
449 sclp_vt220_emit_current();
450 spin_lock_irqsave(&sclp_vt220_lock, flags);
451 buf += written;
452 count -= written;
453 } while (count > 0);
454 /* Setup timer to output current console buffer after some time */
455 if (sclp_vt220_current_request != NULL &&
456 !timer_pending(&sclp_vt220_timer) && do_schedule) {
457 sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY;
458 add_timer(&sclp_vt220_timer);
460 out:
461 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
462 return overall_written;
466 * This routine is called by the kernel to write a series of
467 * characters to the tty device. The characters may come from
468 * user space or kernel space. This routine will return the
469 * number of characters actually accepted for writing.
471 static int
472 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
474 return __sclp_vt220_write(buf, count, 1, 0, 1);
477 #define SCLP_VT220_SESSION_ENDED 0x01
478 #define SCLP_VT220_SESSION_STARTED 0x80
479 #define SCLP_VT220_SESSION_DATA 0x00
481 #ifdef CONFIG_MAGIC_SYSRQ
483 static int sysrq_pressed;
484 static struct sysrq_work sysrq;
486 static void sclp_vt220_reset_session(void)
488 sysrq_pressed = 0;
491 static void sclp_vt220_handle_input(const char *buffer, unsigned int count)
493 int i;
495 for (i = 0; i < count; i++) {
496 /* Handle magic sys request */
497 if (buffer[i] == ('O' ^ 0100)) { /* CTRL-O */
499 * If pressed again, reset sysrq_pressed
500 * and flip CTRL-O character
502 sysrq_pressed = !sysrq_pressed;
503 if (sysrq_pressed)
504 continue;
505 } else if (sysrq_pressed) {
506 sysrq.key = buffer[i];
507 schedule_sysrq_work(&sysrq);
508 sysrq_pressed = 0;
509 continue;
511 tty_insert_flip_char(&sclp_vt220_port, buffer[i], 0);
515 #else
517 static void sclp_vt220_reset_session(void)
521 static void sclp_vt220_handle_input(const char *buffer, unsigned int count)
523 tty_insert_flip_string(&sclp_vt220_port, buffer, count);
526 #endif
529 * Called by the SCLP to report incoming event buffers.
531 static void
532 sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
534 char *buffer;
535 unsigned int count;
537 buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header));
538 count = evbuf->length - sizeof(struct evbuf_header);
540 switch (*buffer) {
541 case SCLP_VT220_SESSION_ENDED:
542 case SCLP_VT220_SESSION_STARTED:
543 sclp_vt220_reset_session();
544 break;
545 case SCLP_VT220_SESSION_DATA:
546 /* Send input to line discipline */
547 buffer++;
548 count--;
549 sclp_vt220_handle_input(buffer, count);
550 tty_flip_buffer_push(&sclp_vt220_port);
551 break;
556 * This routine is called when a particular tty device is opened.
558 static int
559 sclp_vt220_open(struct tty_struct *tty, struct file *filp)
561 if (tty->count == 1) {
562 tty_port_tty_set(&sclp_vt220_port, tty);
563 sclp_vt220_port.low_latency = 0;
564 if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
565 tty->winsize.ws_row = 24;
566 tty->winsize.ws_col = 80;
569 return 0;
573 * This routine is called when a particular tty device is closed.
575 static void
576 sclp_vt220_close(struct tty_struct *tty, struct file *filp)
578 if (tty->count == 1)
579 tty_port_tty_set(&sclp_vt220_port, NULL);
583 * This routine is called by the kernel to write a single
584 * character to the tty device. If the kernel uses this routine,
585 * it must call the flush_chars() routine (if defined) when it is
586 * done stuffing characters into the driver.
588 static int
589 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
591 return __sclp_vt220_write(&ch, 1, 0, 0, 1);
595 * This routine is called by the kernel after it has written a
596 * series of characters to the tty device using put_char().
598 static void
599 sclp_vt220_flush_chars(struct tty_struct *tty)
601 if (!sclp_vt220_queue_running)
602 sclp_vt220_emit_current();
603 else
604 sclp_vt220_flush_later = 1;
608 * This routine returns the numbers of characters the tty driver
609 * will accept for queuing to be written. This number is subject
610 * to change as output buffers get emptied, or if the output flow
611 * control is acted.
613 static int
614 sclp_vt220_write_room(struct tty_struct *tty)
616 unsigned long flags;
617 struct list_head *l;
618 int count;
620 spin_lock_irqsave(&sclp_vt220_lock, flags);
621 count = 0;
622 if (sclp_vt220_current_request != NULL)
623 count = sclp_vt220_space_left(sclp_vt220_current_request);
624 list_for_each(l, &sclp_vt220_empty)
625 count += SCLP_VT220_MAX_CHARS_PER_BUFFER;
626 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
627 return count;
631 * Return number of buffered chars.
633 static int
634 sclp_vt220_chars_in_buffer(struct tty_struct *tty)
636 unsigned long flags;
637 struct list_head *l;
638 struct sclp_vt220_request *r;
639 int count;
641 spin_lock_irqsave(&sclp_vt220_lock, flags);
642 count = 0;
643 if (sclp_vt220_current_request != NULL)
644 count = sclp_vt220_chars_stored(sclp_vt220_current_request);
645 list_for_each(l, &sclp_vt220_outqueue) {
646 r = list_entry(l, struct sclp_vt220_request, list);
647 count += sclp_vt220_chars_stored(r);
649 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
650 return count;
654 * Pass on all buffers to the hardware. Return only when there are no more
655 * buffers pending.
657 static void
658 sclp_vt220_flush_buffer(struct tty_struct *tty)
660 sclp_vt220_emit_current();
663 /* Release allocated pages. */
664 static void __init __sclp_vt220_free_pages(void)
666 struct list_head *page, *p;
668 list_for_each_safe(page, p, &sclp_vt220_empty) {
669 list_del(page);
670 free_page((unsigned long) page);
674 /* Release memory and unregister from sclp core. Controlled by init counting -
675 * only the last invoker will actually perform these actions. */
676 static void __init __sclp_vt220_cleanup(void)
678 sclp_vt220_init_count--;
679 if (sclp_vt220_init_count != 0)
680 return;
681 sclp_unregister(&sclp_vt220_register);
682 __sclp_vt220_free_pages();
683 tty_port_destroy(&sclp_vt220_port);
686 /* Allocate buffer pages and register with sclp core. Controlled by init
687 * counting - only the first invoker will actually perform these actions. */
688 static int __init __sclp_vt220_init(int num_pages)
690 void *page;
691 int i;
692 int rc;
694 sclp_vt220_init_count++;
695 if (sclp_vt220_init_count != 1)
696 return 0;
697 spin_lock_init(&sclp_vt220_lock);
698 INIT_LIST_HEAD(&sclp_vt220_empty);
699 INIT_LIST_HEAD(&sclp_vt220_outqueue);
700 timer_setup(&sclp_vt220_timer, sclp_vt220_timeout, 0);
701 tty_port_init(&sclp_vt220_port);
702 sclp_vt220_current_request = NULL;
703 sclp_vt220_buffered_chars = 0;
704 sclp_vt220_flush_later = 0;
706 /* Allocate pages for output buffering */
707 rc = -ENOMEM;
708 for (i = 0; i < num_pages; i++) {
709 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
710 if (!page)
711 goto out;
712 list_add_tail(page, &sclp_vt220_empty);
714 rc = sclp_register(&sclp_vt220_register);
715 out:
716 if (rc) {
717 __sclp_vt220_free_pages();
718 sclp_vt220_init_count--;
719 tty_port_destroy(&sclp_vt220_port);
721 return rc;
724 static const struct tty_operations sclp_vt220_ops = {
725 .open = sclp_vt220_open,
726 .close = sclp_vt220_close,
727 .write = sclp_vt220_write,
728 .put_char = sclp_vt220_put_char,
729 .flush_chars = sclp_vt220_flush_chars,
730 .write_room = sclp_vt220_write_room,
731 .chars_in_buffer = sclp_vt220_chars_in_buffer,
732 .flush_buffer = sclp_vt220_flush_buffer,
736 * Register driver with SCLP and Linux and initialize internal tty structures.
738 static int __init sclp_vt220_tty_init(void)
740 struct tty_driver *driver;
741 int rc;
743 /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
744 * symmetry between VM and LPAR systems regarding ttyS1. */
745 driver = alloc_tty_driver(1);
746 if (!driver)
747 return -ENOMEM;
748 rc = __sclp_vt220_init(MAX_KMEM_PAGES);
749 if (rc)
750 goto out_driver;
752 driver->driver_name = SCLP_VT220_DRIVER_NAME;
753 driver->name = SCLP_VT220_DEVICE_NAME;
754 driver->major = SCLP_VT220_MAJOR;
755 driver->minor_start = SCLP_VT220_MINOR;
756 driver->type = TTY_DRIVER_TYPE_SYSTEM;
757 driver->subtype = SYSTEM_TYPE_TTY;
758 driver->init_termios = tty_std_termios;
759 driver->flags = TTY_DRIVER_REAL_RAW;
760 tty_set_operations(driver, &sclp_vt220_ops);
761 tty_port_link_device(&sclp_vt220_port, driver, 0);
763 rc = tty_register_driver(driver);
764 if (rc)
765 goto out_init;
766 rc = sclp_register(&sclp_vt220_register_input);
767 if (rc)
768 goto out_reg;
769 sclp_vt220_driver = driver;
770 return 0;
772 out_reg:
773 tty_unregister_driver(driver);
774 out_init:
775 __sclp_vt220_cleanup();
776 out_driver:
777 put_tty_driver(driver);
778 return rc;
780 __initcall(sclp_vt220_tty_init);
782 static void __sclp_vt220_flush_buffer(void)
784 unsigned long flags;
786 sclp_vt220_emit_current();
787 spin_lock_irqsave(&sclp_vt220_lock, flags);
788 if (timer_pending(&sclp_vt220_timer))
789 del_timer(&sclp_vt220_timer);
790 while (sclp_vt220_queue_running) {
791 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
792 sclp_sync_wait();
793 spin_lock_irqsave(&sclp_vt220_lock, flags);
795 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
799 * Resume console: If there are cached messages, emit them.
801 static void sclp_vt220_resume(void)
803 unsigned long flags;
805 spin_lock_irqsave(&sclp_vt220_lock, flags);
806 sclp_vt220_suspended = 0;
807 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
808 sclp_vt220_emit_current();
812 * Suspend console: Set suspend flag and flush console
814 static void sclp_vt220_suspend(void)
816 unsigned long flags;
818 spin_lock_irqsave(&sclp_vt220_lock, flags);
819 sclp_vt220_suspended = 1;
820 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
821 __sclp_vt220_flush_buffer();
824 static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
825 enum sclp_pm_event sclp_pm_event)
827 switch (sclp_pm_event) {
828 case SCLP_PM_EVENT_FREEZE:
829 sclp_vt220_suspend();
830 break;
831 case SCLP_PM_EVENT_RESTORE:
832 case SCLP_PM_EVENT_THAW:
833 sclp_vt220_resume();
834 break;
838 #ifdef CONFIG_SCLP_VT220_CONSOLE
840 static void
841 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
843 __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0);
846 static struct tty_driver *
847 sclp_vt220_con_device(struct console *c, int *index)
849 *index = 0;
850 return sclp_vt220_driver;
853 static int
854 sclp_vt220_notify(struct notifier_block *self,
855 unsigned long event, void *data)
857 __sclp_vt220_flush_buffer();
858 return NOTIFY_OK;
861 static struct notifier_block on_panic_nb = {
862 .notifier_call = sclp_vt220_notify,
863 .priority = 1,
866 static struct notifier_block on_reboot_nb = {
867 .notifier_call = sclp_vt220_notify,
868 .priority = 1,
871 /* Structure needed to register with printk */
872 static struct console sclp_vt220_console =
874 .name = SCLP_VT220_CONSOLE_NAME,
875 .write = sclp_vt220_con_write,
876 .device = sclp_vt220_con_device,
877 .flags = CON_PRINTBUFFER,
878 .index = SCLP_VT220_CONSOLE_INDEX
881 static int __init
882 sclp_vt220_con_init(void)
884 int rc;
886 rc = __sclp_vt220_init(sclp_console_pages);
887 if (rc)
888 return rc;
889 /* Attach linux console */
890 atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
891 register_reboot_notifier(&on_reboot_nb);
892 register_console(&sclp_vt220_console);
893 return 0;
896 console_initcall(sclp_vt220_con_init);
897 #endif /* CONFIG_SCLP_VT220_CONSOLE */