xref: /linux/drivers/s390/char/con3215.c (revision f7af616c632ee2ac3af0876fe33bf9e0232e665a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * 3215 line mode terminal driver.
4  *
5  * Copyright IBM Corp. 1999, 2009
6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7  *
8  * Updated:
9  *  Aug-2000: Added tab support
10  *	      Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>
11  */
12 
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 <linux/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 	wait_queue_head_t empty_wait; /* wait queue for flushing */
89 	struct timer_list timer;      /* timer for delayed output */
90 	int line_pos;		      /* position on the line (for tabs) */
91 	char ubuffer[80];	      /* copy_from_user buffer */
92 };
93 
94 /* array of 3215 devices structures */
95 static struct raw3215_info *raw3215[NR_3215];
96 /* spinlock to protect the raw3215 array */
97 static DEFINE_SPINLOCK(raw3215_device_lock);
98 /* list of free request structures */
99 static struct raw3215_req *raw3215_freelist;
100 /* spinlock to protect free list */
101 static DEFINE_SPINLOCK(raw3215_freelist_lock);
102 
103 static struct tty_driver *tty3215_driver;
104 
105 /*
106  * Get a request structure from the free list
107  */
108 static inline struct raw3215_req *raw3215_alloc_req(void)
109 {
110 	struct raw3215_req *req;
111 	unsigned long flags;
112 
113 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
114 	req = raw3215_freelist;
115 	raw3215_freelist = req->next;
116 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
117 	return req;
118 }
119 
120 /*
121  * Put a request structure back to the free list
122  */
123 static inline void raw3215_free_req(struct raw3215_req *req)
124 {
125 	unsigned long flags;
126 
127 	if (req->type == RAW3215_FREE)
128 		return;		/* don't free a free request */
129 	req->type = RAW3215_FREE;
130 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
131 	req->next = raw3215_freelist;
132 	raw3215_freelist = req;
133 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
134 }
135 
136 /*
137  * Set up a read request that reads up to 160 byte from the 3215 device.
138  * If there is a queued read request it is used, but that shouldn't happen
139  * because a 3215 terminal won't accept a new read before the old one is
140  * completed.
141  */
142 static void raw3215_mk_read_req(struct raw3215_info *raw)
143 {
144 	struct raw3215_req *req;
145 	struct ccw1 *ccw;
146 
147 	/* there can only be ONE read request at a time */
148 	req = raw->queued_read;
149 	if (req == NULL) {
150 		/* no queued read request, use new req structure */
151 		req = raw3215_alloc_req();
152 		req->type = RAW3215_READ;
153 		req->info = raw;
154 		raw->queued_read = req;
155 	}
156 
157 	ccw = req->ccws;
158 	ccw->cmd_code = 0x0A; /* read inquiry */
159 	ccw->flags = 0x20;    /* ignore incorrect length */
160 	ccw->count = 160;
161 	ccw->cda = (__u32) __pa(raw->inbuf);
162 }
163 
164 /*
165  * Set up a write request with the information from the main structure.
166  * A ccw chain is created that writes as much as possible from the output
167  * buffer to the 3215 device. If a queued write exists it is replaced by
168  * the new, probably lengthened request.
169  */
170 static void raw3215_mk_write_req(struct raw3215_info *raw)
171 {
172 	struct raw3215_req *req;
173 	struct ccw1 *ccw;
174 	int len, count, ix, lines;
175 
176 	if (raw->count <= raw->written)
177 		return;
178 	/* check if there is a queued write request */
179 	req = raw->queued_write;
180 	if (req == NULL) {
181 		/* no queued write request, use new req structure */
182 		req = raw3215_alloc_req();
183 		req->type = RAW3215_WRITE;
184 		req->info = raw;
185 		raw->queued_write = req;
186 	} else {
187 		raw->written -= req->len;
188 	}
189 
190 	ccw = req->ccws;
191 	req->start = (raw->head - raw->count + raw->written) &
192 		     (RAW3215_BUFFER_SIZE - 1);
193 	/*
194 	 * now we have to count newlines. We can at max accept
195 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
196 	 * a restriction in VM
197 	 */
198 	lines = 0;
199 	ix = req->start;
200 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
201 		if (raw->buffer[ix] == 0x15)
202 			lines++;
203 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
204 	}
205 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
206 	if (len > RAW3215_MAX_BYTES)
207 		len = RAW3215_MAX_BYTES;
208 	req->len = len;
209 	raw->written += len;
210 
211 	/* set the indication if we should try to enlarge this request */
212 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
213 
214 	ix = req->start;
215 	while (len > 0) {
216 		if (ccw > req->ccws)
217 			ccw[-1].flags |= 0x40; /* use command chaining */
218 		ccw->cmd_code = 0x01; /* write, auto carrier return */
219 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
220 		ccw->cda =
221 			(__u32) __pa(raw->buffer + ix);
222 		count = len;
223 		if (ix + count > RAW3215_BUFFER_SIZE)
224 			count = RAW3215_BUFFER_SIZE - ix;
225 		ccw->count = count;
226 		len -= count;
227 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
228 		ccw++;
229 	}
230 	/*
231 	 * Add a NOP to the channel program. 3215 devices are purely
232 	 * emulated and its much better to avoid the channel end
233 	 * interrupt in this case.
234 	 */
235 	if (ccw > req->ccws)
236 		ccw[-1].flags |= 0x40; /* use command chaining */
237 	ccw->cmd_code = 0x03; /* NOP */
238 	ccw->flags = 0;
239 	ccw->cda = 0;
240 	ccw->count = 1;
241 }
242 
243 /*
244  * Start a read or a write request
245  */
246 static void raw3215_start_io(struct raw3215_info *raw)
247 {
248 	struct raw3215_req *req;
249 	int res;
250 
251 	req = raw->queued_read;
252 	if (req != NULL &&
253 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
254 		/* dequeue request */
255 		raw->queued_read = NULL;
256 		res = ccw_device_start(raw->cdev, req->ccws,
257 				       (unsigned long) req, 0, 0);
258 		if (res != 0) {
259 			/* do_IO failed, put request back to queue */
260 			raw->queued_read = req;
261 		} else {
262 			raw->flags |= RAW3215_WORKING;
263 		}
264 	}
265 	req = raw->queued_write;
266 	if (req != NULL &&
267 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
268 		/* dequeue request */
269 		raw->queued_write = NULL;
270 		res = ccw_device_start(raw->cdev, req->ccws,
271 				       (unsigned long) req, 0, 0);
272 		if (res != 0) {
273 			/* do_IO failed, put request back to queue */
274 			raw->queued_write = req;
275 		} else {
276 			raw->flags |= RAW3215_WORKING;
277 		}
278 	}
279 }
280 
281 /*
282  * Function to start a delayed output after RAW3215_TIMEOUT seconds
283  */
284 static void raw3215_timeout(struct timer_list *t)
285 {
286 	struct raw3215_info *raw = from_timer(raw, t, timer);
287 	unsigned long flags;
288 
289 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
290 	raw->flags &= ~RAW3215_TIMER_RUNS;
291 	raw3215_mk_write_req(raw);
292 	raw3215_start_io(raw);
293 	if ((raw->queued_read || raw->queued_write) &&
294 	    !(raw->flags & RAW3215_WORKING) &&
295 	    !(raw->flags & RAW3215_TIMER_RUNS)) {
296 		raw->timer.expires = RAW3215_TIMEOUT + jiffies;
297 		add_timer(&raw->timer);
298 		raw->flags |= RAW3215_TIMER_RUNS;
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 (!tty_port_initialized(&raw->port))
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 		}
321 	}
322 	if ((raw->queued_read || raw->queued_write) &&
323 	    !(raw->flags & RAW3215_WORKING) &&
324 	    !(raw->flags & RAW3215_TIMER_RUNS)) {
325 		raw->timer.expires = RAW3215_TIMEOUT + jiffies;
326 		add_timer(&raw->timer);
327 		raw->flags |= RAW3215_TIMER_RUNS;
328 	}
329 }
330 
331 /*
332  * Try to start the next IO and wake up processes waiting on the tty.
333  */
334 static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
335 {
336 	raw3215_mk_write_req(raw);
337 	raw3215_try_io(raw);
338 	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
339 		tty_wakeup(tty);
340 }
341 
342 /*
343  * Interrupt routine, called from common io layer
344  */
345 static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
346 			struct irb *irb)
347 {
348 	struct raw3215_info *raw;
349 	struct raw3215_req *req;
350 	struct tty_struct *tty;
351 	int cstat, dstat;
352 	int count;
353 
354 	raw = dev_get_drvdata(&cdev->dev);
355 	req = (struct raw3215_req *) intparm;
356 	tty = tty_port_tty_get(&raw->port);
357 	cstat = irb->scsw.cmd.cstat;
358 	dstat = irb->scsw.cmd.dstat;
359 	if (cstat != 0)
360 		raw3215_next_io(raw, tty);
361 	if (dstat & 0x01) { /* we got a unit exception */
362 		dstat &= ~0x01;	 /* we can ignore it */
363 	}
364 	switch (dstat) {
365 	case 0x80:
366 		if (cstat != 0)
367 			break;
368 		/* Attention interrupt, someone hit the enter key */
369 		raw3215_mk_read_req(raw);
370 		raw3215_next_io(raw, tty);
371 		break;
372 	case 0x08:
373 	case 0x0C:
374 		/* Channel end interrupt. */
375 		if ((raw = req->info) == NULL)
376 			goto put_tty;	     /* That shouldn't happen ... */
377 		if (req->type == RAW3215_READ) {
378 			/* store residual count, then wait for device end */
379 			req->residual = irb->scsw.cmd.count;
380 		}
381 		if (dstat == 0x08)
382 			break;
383 		fallthrough;
384 	case 0x04:
385 		/* Device end interrupt. */
386 		if ((raw = req->info) == NULL)
387 			goto put_tty;	     /* That shouldn't happen ... */
388 		if (req->type == RAW3215_READ && tty != NULL) {
389 			unsigned int cchar;
390 
391 			count = 160 - req->residual;
392 			EBCASC(raw->inbuf, count);
393 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
394 			switch (cchar & CTRLCHAR_MASK) {
395 			case CTRLCHAR_SYSRQ:
396 				break;
397 
398 			case CTRLCHAR_CTRL:
399 				tty_insert_flip_char(&raw->port, cchar,
400 						TTY_NORMAL);
401 				tty_flip_buffer_push(&raw->port);
402 				break;
403 
404 			case CTRLCHAR_NONE:
405 				if (count < 2 ||
406 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
407 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
408 					/* add the auto \n */
409 					raw->inbuf[count] = '\n';
410 					count++;
411 				} else
412 					count -= 2;
413 				tty_insert_flip_string(&raw->port, raw->inbuf,
414 						count);
415 				tty_flip_buffer_push(&raw->port);
416 				break;
417 			}
418 		} else if (req->type == RAW3215_WRITE) {
419 			raw->count -= req->len;
420 			raw->written -= req->len;
421 		}
422 		raw->flags &= ~RAW3215_WORKING;
423 		raw3215_free_req(req);
424 		/* check for empty wait */
425 		if (waitqueue_active(&raw->empty_wait) &&
426 		    raw->queued_write == NULL &&
427 		    raw->queued_read == NULL) {
428 			wake_up_interruptible(&raw->empty_wait);
429 		}
430 		raw3215_next_io(raw, tty);
431 		break;
432 	default:
433 		/* Strange interrupt, I'll do my best to clean up */
434 		if (req != NULL && req->type != RAW3215_FREE) {
435 			if (req->type == RAW3215_WRITE) {
436 				raw->count -= req->len;
437 				raw->written -= req->len;
438 			}
439 			raw->flags &= ~RAW3215_WORKING;
440 			raw3215_free_req(req);
441 		}
442 		raw3215_next_io(raw, tty);
443 	}
444 put_tty:
445 	tty_kref_put(tty);
446 }
447 
448 /*
449  * Wait until length bytes are available int the output buffer.
450  * Has to be called with the s390irq lock held. Can be called
451  * disabled.
452  */
453 static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
454 {
455 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
456 		/* there might be a request pending */
457 		raw->flags |= RAW3215_FLUSHING;
458 		raw3215_mk_write_req(raw);
459 		raw3215_try_io(raw);
460 		raw->flags &= ~RAW3215_FLUSHING;
461 #ifdef CONFIG_TN3215_CONSOLE
462 		ccw_device_wait_idle(raw->cdev);
463 #endif
464 		/* Enough room freed up ? */
465 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
466 			break;
467 		/* there might be another cpu waiting for the lock */
468 		spin_unlock(get_ccwdev_lock(raw->cdev));
469 		udelay(100);
470 		spin_lock(get_ccwdev_lock(raw->cdev));
471 	}
472 }
473 
474 /*
475  * String write routine for 3215 devices
476  */
477 static void raw3215_write(struct raw3215_info *raw, const char *str,
478 			  unsigned int length)
479 {
480 	unsigned long flags;
481 	int c, count;
482 
483 	while (length > 0) {
484 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
485 		count = (length > RAW3215_BUFFER_SIZE) ?
486 					     RAW3215_BUFFER_SIZE : length;
487 		length -= count;
488 
489 		raw3215_make_room(raw, count);
490 
491 		/* copy string to output buffer and convert it to EBCDIC */
492 		while (1) {
493 			c = min_t(int, count,
494 				  min(RAW3215_BUFFER_SIZE - raw->count,
495 				      RAW3215_BUFFER_SIZE - raw->head));
496 			if (c <= 0)
497 				break;
498 			memcpy(raw->buffer + raw->head, str, c);
499 			ASCEBC(raw->buffer + raw->head, c);
500 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
501 			raw->count += c;
502 			raw->line_pos += c;
503 			str += c;
504 			count -= c;
505 		}
506 		if (!(raw->flags & RAW3215_WORKING)) {
507 			raw3215_mk_write_req(raw);
508 			/* start or queue request */
509 			raw3215_try_io(raw);
510 		}
511 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
512 	}
513 }
514 
515 /*
516  * Put character routine for 3215 devices
517  */
518 static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
519 {
520 	unsigned long flags;
521 	unsigned int length, i;
522 
523 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
524 	if (ch == '\t') {
525 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
526 		raw->line_pos += length;
527 		ch = ' ';
528 	} else if (ch == '\n') {
529 		length = 1;
530 		raw->line_pos = 0;
531 	} else {
532 		length = 1;
533 		raw->line_pos++;
534 	}
535 	raw3215_make_room(raw, length);
536 
537 	for (i = 0; i < length; i++) {
538 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
539 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
540 		raw->count++;
541 	}
542 	if (!(raw->flags & RAW3215_WORKING)) {
543 		raw3215_mk_write_req(raw);
544 		/* start or queue request */
545 		raw3215_try_io(raw);
546 	}
547 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
548 }
549 
550 /*
551  * Flush routine, it simply sets the flush flag and tries to start
552  * pending IO.
553  */
554 static void raw3215_flush_buffer(struct raw3215_info *raw)
555 {
556 	unsigned long flags;
557 
558 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
559 	if (raw->count > 0) {
560 		raw->flags |= RAW3215_FLUSHING;
561 		raw3215_try_io(raw);
562 		raw->flags &= ~RAW3215_FLUSHING;
563 	}
564 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
565 }
566 
567 /*
568  * Fire up a 3215 device.
569  */
570 static int raw3215_startup(struct raw3215_info *raw)
571 {
572 	unsigned long flags;
573 
574 	if (tty_port_initialized(&raw->port))
575 		return 0;
576 	raw->line_pos = 0;
577 	tty_port_set_initialized(&raw->port, 1);
578 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
579 	raw3215_try_io(raw);
580 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
581 
582 	return 0;
583 }
584 
585 /*
586  * Shutdown a 3215 device.
587  */
588 static void raw3215_shutdown(struct raw3215_info *raw)
589 {
590 	DECLARE_WAITQUEUE(wait, current);
591 	unsigned long flags;
592 
593 	if (!tty_port_initialized(&raw->port) || (raw->flags & RAW3215_FIXED))
594 		return;
595 	/* Wait for outstanding requests, then free irq */
596 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
597 	if ((raw->flags & RAW3215_WORKING) ||
598 	    raw->queued_write != NULL ||
599 	    raw->queued_read != NULL) {
600 		add_wait_queue(&raw->empty_wait, &wait);
601 		set_current_state(TASK_INTERRUPTIBLE);
602 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
603 		schedule();
604 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
605 		remove_wait_queue(&raw->empty_wait, &wait);
606 		set_current_state(TASK_RUNNING);
607 		tty_port_set_initialized(&raw->port, 1);
608 	}
609 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
610 }
611 
612 static struct raw3215_info *raw3215_alloc_info(void)
613 {
614 	struct raw3215_info *info;
615 
616 	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
617 	if (!info)
618 		return NULL;
619 
620 	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
621 	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
622 	if (!info->buffer || !info->inbuf) {
623 		kfree(info->inbuf);
624 		kfree(info->buffer);
625 		kfree(info);
626 		return NULL;
627 	}
628 
629 	timer_setup(&info->timer, raw3215_timeout, 0);
630 	init_waitqueue_head(&info->empty_wait);
631 	tty_port_init(&info->port);
632 
633 	return info;
634 }
635 
636 static void raw3215_free_info(struct raw3215_info *raw)
637 {
638 	kfree(raw->inbuf);
639 	kfree(raw->buffer);
640 	tty_port_destroy(&raw->port);
641 	kfree(raw);
642 }
643 
644 static int raw3215_probe (struct ccw_device *cdev)
645 {
646 	struct raw3215_info *raw;
647 	int line;
648 
649 	/* Console is special. */
650 	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
651 		return 0;
652 
653 	raw = raw3215_alloc_info();
654 	if (raw == NULL)
655 		return -ENOMEM;
656 
657 	raw->cdev = cdev;
658 	dev_set_drvdata(&cdev->dev, raw);
659 	cdev->handler = raw3215_irq;
660 
661 	spin_lock(&raw3215_device_lock);
662 	for (line = 0; line < NR_3215; line++) {
663 		if (!raw3215[line]) {
664 			raw3215[line] = raw;
665 			break;
666 		}
667 	}
668 	spin_unlock(&raw3215_device_lock);
669 	if (line == NR_3215) {
670 		raw3215_free_info(raw);
671 		return -ENODEV;
672 	}
673 
674 	return 0;
675 }
676 
677 static void raw3215_remove (struct ccw_device *cdev)
678 {
679 	struct raw3215_info *raw;
680 	unsigned int line;
681 
682 	ccw_device_set_offline(cdev);
683 	raw = dev_get_drvdata(&cdev->dev);
684 	if (raw) {
685 		spin_lock(&raw3215_device_lock);
686 		for (line = 0; line < NR_3215; line++)
687 			if (raw3215[line] == raw)
688 				break;
689 		raw3215[line] = NULL;
690 		spin_unlock(&raw3215_device_lock);
691 		dev_set_drvdata(&cdev->dev, NULL);
692 		raw3215_free_info(raw);
693 	}
694 }
695 
696 static int raw3215_set_online (struct ccw_device *cdev)
697 {
698 	struct raw3215_info *raw;
699 
700 	raw = dev_get_drvdata(&cdev->dev);
701 	if (!raw)
702 		return -ENODEV;
703 
704 	return raw3215_startup(raw);
705 }
706 
707 static int raw3215_set_offline (struct ccw_device *cdev)
708 {
709 	struct raw3215_info *raw;
710 
711 	raw = dev_get_drvdata(&cdev->dev);
712 	if (!raw)
713 		return -ENODEV;
714 
715 	raw3215_shutdown(raw);
716 
717 	return 0;
718 }
719 
720 static struct ccw_device_id raw3215_id[] = {
721 	{ CCW_DEVICE(0x3215, 0) },
722 	{ /* end of list */ },
723 };
724 
725 static struct ccw_driver raw3215_ccw_driver = {
726 	.driver = {
727 		.name	= "3215",
728 		.owner	= THIS_MODULE,
729 	},
730 	.ids		= raw3215_id,
731 	.probe		= &raw3215_probe,
732 	.remove		= &raw3215_remove,
733 	.set_online	= &raw3215_set_online,
734 	.set_offline	= &raw3215_set_offline,
735 	.int_class	= IRQIO_C15,
736 };
737 
738 #ifdef CONFIG_TN3215_CONSOLE
739 /*
740  * Write a string to the 3215 console
741  */
742 static void con3215_write(struct console *co, const char *str,
743 			  unsigned int count)
744 {
745 	struct raw3215_info *raw;
746 	int i;
747 
748 	if (count <= 0)
749 		return;
750 	raw = raw3215[0];	/* console 3215 is the first one */
751 	while (count > 0) {
752 		for (i = 0; i < count; i++)
753 			if (str[i] == '\t' || str[i] == '\n')
754 				break;
755 		raw3215_write(raw, str, i);
756 		count -= i;
757 		str += i;
758 		if (count > 0) {
759 			raw3215_putchar(raw, *str);
760 			count--;
761 			str++;
762 		}
763 	}
764 }
765 
766 static struct tty_driver *con3215_device(struct console *c, int *index)
767 {
768 	*index = c->index;
769 	return tty3215_driver;
770 }
771 
772 /*
773  * panic() calls con3215_flush through a panic_notifier
774  * before the system enters a disabled, endless loop.
775  */
776 static void con3215_flush(void)
777 {
778 	struct raw3215_info *raw;
779 	unsigned long flags;
780 
781 	raw = raw3215[0];  /* console 3215 is the first one */
782 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
783 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
784 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
785 }
786 
787 static int con3215_notify(struct notifier_block *self,
788 			  unsigned long event, void *data)
789 {
790 	con3215_flush();
791 	return NOTIFY_OK;
792 }
793 
794 static struct notifier_block on_panic_nb = {
795 	.notifier_call = con3215_notify,
796 	.priority = 0,
797 };
798 
799 static struct notifier_block on_reboot_nb = {
800 	.notifier_call = con3215_notify,
801 	.priority = 0,
802 };
803 
804 /*
805  *  The console structure for the 3215 console
806  */
807 static struct console con3215 = {
808 	.name	 = "ttyS",
809 	.write	 = con3215_write,
810 	.device	 = con3215_device,
811 	.flags	 = CON_PRINTBUFFER,
812 };
813 
814 /*
815  * 3215 console initialization code called from console_init().
816  */
817 static int __init con3215_init(void)
818 {
819 	struct ccw_device *cdev;
820 	struct raw3215_info *raw;
821 	struct raw3215_req *req;
822 	int i;
823 
824 	/* Check if 3215 is to be the console */
825 	if (!CONSOLE_IS_3215)
826 		return -ENODEV;
827 
828 	/* Set the console mode for VM */
829 	if (MACHINE_IS_VM) {
830 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
831 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
832 	}
833 
834 	/* allocate 3215 request structures */
835 	raw3215_freelist = NULL;
836 	for (i = 0; i < NR_3215_REQ; i++) {
837 		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
838 		if (!req)
839 			return -ENOMEM;
840 		req->next = raw3215_freelist;
841 		raw3215_freelist = req;
842 	}
843 
844 	cdev = ccw_device_create_console(&raw3215_ccw_driver);
845 	if (IS_ERR(cdev))
846 		return -ENODEV;
847 
848 	raw3215[0] = raw = raw3215_alloc_info();
849 	raw->cdev = cdev;
850 	dev_set_drvdata(&cdev->dev, raw);
851 	cdev->handler = raw3215_irq;
852 
853 	raw->flags |= RAW3215_FIXED;
854 	if (ccw_device_enable_console(cdev)) {
855 		ccw_device_destroy_console(cdev);
856 		raw3215_free_info(raw);
857 		raw3215[0] = NULL;
858 		return -ENODEV;
859 	}
860 
861 	/* Request the console irq */
862 	if (raw3215_startup(raw) != 0) {
863 		raw3215_free_info(raw);
864 		raw3215[0] = NULL;
865 		return -ENODEV;
866 	}
867 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
868 	register_reboot_notifier(&on_reboot_nb);
869 	register_console(&con3215);
870 	return 0;
871 }
872 console_initcall(con3215_init);
873 #endif
874 
875 static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
876 {
877 	struct raw3215_info *raw;
878 
879 	raw = raw3215[tty->index];
880 	if (raw == NULL)
881 		return -ENODEV;
882 
883 	tty->driver_data = raw;
884 
885 	return tty_port_install(&raw->port, driver, tty);
886 }
887 
888 /*
889  * tty3215_open
890  *
891  * This routine is called whenever a 3215 tty is opened.
892  */
893 static int tty3215_open(struct tty_struct *tty, struct file * filp)
894 {
895 	struct raw3215_info *raw = tty->driver_data;
896 
897 	tty_port_tty_set(&raw->port, tty);
898 
899 	/*
900 	 * Start up 3215 device
901 	 */
902 	return raw3215_startup(raw);
903 }
904 
905 /*
906  * tty3215_close()
907  *
908  * This routine is called when the 3215 tty is closed. We wait
909  * for the remaining request to be completed. Then we clean up.
910  */
911 static void tty3215_close(struct tty_struct *tty, struct file * filp)
912 {
913 	struct raw3215_info *raw = tty->driver_data;
914 
915 	if (raw == NULL || tty->count > 1)
916 		return;
917 	tty->closing = 1;
918 	/* Shutdown the terminal */
919 	raw3215_shutdown(raw);
920 	tty->closing = 0;
921 	tty_port_tty_set(&raw->port, NULL);
922 }
923 
924 /*
925  * Returns the amount of free space in the output buffer.
926  */
927 static int tty3215_write_room(struct tty_struct *tty)
928 {
929 	struct raw3215_info *raw = tty->driver_data;
930 
931 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
932 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
933 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
934 	else
935 		return 0;
936 }
937 
938 /*
939  * String write routine for 3215 ttys
940  */
941 static int tty3215_write(struct tty_struct * tty,
942 			 const unsigned char *buf, int count)
943 {
944 	struct raw3215_info *raw = tty->driver_data;
945 	int i, written;
946 
947 	written = count;
948 	while (count > 0) {
949 		for (i = 0; i < count; i++)
950 			if (buf[i] == '\t' || buf[i] == '\n')
951 				break;
952 		raw3215_write(raw, buf, i);
953 		count -= i;
954 		buf += i;
955 		if (count > 0) {
956 			raw3215_putchar(raw, *buf);
957 			count--;
958 			buf++;
959 		}
960 	}
961 	return written;
962 }
963 
964 /*
965  * Put character routine for 3215 ttys
966  */
967 static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
968 {
969 	struct raw3215_info *raw = tty->driver_data;
970 
971 	raw3215_putchar(raw, ch);
972 
973 	return 1;
974 }
975 
976 static void tty3215_flush_chars(struct tty_struct *tty)
977 {
978 }
979 
980 /*
981  * Returns the number of characters in the output buffer
982  */
983 static int tty3215_chars_in_buffer(struct tty_struct *tty)
984 {
985 	struct raw3215_info *raw = tty->driver_data;
986 
987 	return raw->count;
988 }
989 
990 static void tty3215_flush_buffer(struct tty_struct *tty)
991 {
992 	struct raw3215_info *raw = tty->driver_data;
993 
994 	raw3215_flush_buffer(raw);
995 	tty_wakeup(tty);
996 }
997 
998 /*
999  * Disable reading from a 3215 tty
1000  */
1001 static void tty3215_throttle(struct tty_struct * tty)
1002 {
1003 	struct raw3215_info *raw = tty->driver_data;
1004 
1005 	raw->flags |= RAW3215_THROTTLED;
1006 }
1007 
1008 /*
1009  * Enable reading from a 3215 tty
1010  */
1011 static void tty3215_unthrottle(struct tty_struct * tty)
1012 {
1013 	struct raw3215_info *raw = tty->driver_data;
1014 	unsigned long flags;
1015 
1016 	if (raw->flags & RAW3215_THROTTLED) {
1017 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1018 		raw->flags &= ~RAW3215_THROTTLED;
1019 		raw3215_try_io(raw);
1020 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1021 	}
1022 }
1023 
1024 /*
1025  * Disable writing to a 3215 tty
1026  */
1027 static void tty3215_stop(struct tty_struct *tty)
1028 {
1029 	struct raw3215_info *raw = tty->driver_data;
1030 
1031 	raw->flags |= RAW3215_STOPPED;
1032 }
1033 
1034 /*
1035  * Enable writing to a 3215 tty
1036  */
1037 static void tty3215_start(struct tty_struct *tty)
1038 {
1039 	struct raw3215_info *raw = tty->driver_data;
1040 	unsigned long flags;
1041 
1042 	if (raw->flags & RAW3215_STOPPED) {
1043 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1044 		raw->flags &= ~RAW3215_STOPPED;
1045 		raw3215_try_io(raw);
1046 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1047 	}
1048 }
1049 
1050 static const struct tty_operations tty3215_ops = {
1051 	.install = tty3215_install,
1052 	.open = tty3215_open,
1053 	.close = tty3215_close,
1054 	.write = tty3215_write,
1055 	.put_char = tty3215_put_char,
1056 	.flush_chars = tty3215_flush_chars,
1057 	.write_room = tty3215_write_room,
1058 	.chars_in_buffer = tty3215_chars_in_buffer,
1059 	.flush_buffer = tty3215_flush_buffer,
1060 	.throttle = tty3215_throttle,
1061 	.unthrottle = tty3215_unthrottle,
1062 	.stop = tty3215_stop,
1063 	.start = tty3215_start,
1064 };
1065 
1066 /*
1067  * 3215 tty registration code called from tty_init().
1068  * Most kernel services (incl. kmalloc) are available at this poimt.
1069  */
1070 static int __init tty3215_init(void)
1071 {
1072 	struct tty_driver *driver;
1073 	int ret;
1074 
1075 	if (!CONSOLE_IS_3215)
1076 		return 0;
1077 
1078 	driver = alloc_tty_driver(NR_3215);
1079 	if (!driver)
1080 		return -ENOMEM;
1081 
1082 	ret = ccw_driver_register(&raw3215_ccw_driver);
1083 	if (ret) {
1084 		put_tty_driver(driver);
1085 		return ret;
1086 	}
1087 	/*
1088 	 * Initialize the tty_driver structure
1089 	 * Entries in tty3215_driver that are NOT initialized:
1090 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1091 	 */
1092 
1093 	driver->driver_name = "tty3215";
1094 	driver->name = "ttyS";
1095 	driver->major = TTY_MAJOR;
1096 	driver->minor_start = 64;
1097 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1098 	driver->subtype = SYSTEM_TYPE_TTY;
1099 	driver->init_termios = tty_std_termios;
1100 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1101 	driver->init_termios.c_oflag = ONLCR;
1102 	driver->init_termios.c_lflag = ISIG;
1103 	driver->flags = TTY_DRIVER_REAL_RAW;
1104 	tty_set_operations(driver, &tty3215_ops);
1105 	ret = tty_register_driver(driver);
1106 	if (ret) {
1107 		put_tty_driver(driver);
1108 		return ret;
1109 	}
1110 	tty3215_driver = driver;
1111 	return 0;
1112 }
1113 device_initcall(tty3215_init);
1114