xref: /linux/drivers/s390/char/con3215.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
1 /*
2  *  drivers/s390/char/con3215.c
3  *    3215 line mode terminal driver.
4  *
5  *  S390 version
6  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
7  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
8  *
9  *  Updated:
10  *   Aug-2000: Added tab support
11  *	       Dan Morrison, IBM Corporation (dmorriso@cse.buffalo.edu)
12  */
13 
14 #include <linux/config.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kdev_t.h>
18 #include <linux/tty.h>
19 #include <linux/vt_kern.h>
20 #include <linux/init.h>
21 #include <linux/console.h>
22 #include <linux/interrupt.h>
23 
24 #include <linux/slab.h>
25 #include <linux/bootmem.h>
26 
27 #include <asm/ccwdev.h>
28 #include <asm/cio.h>
29 #include <asm/io.h>
30 #include <asm/ebcdic.h>
31 #include <asm/uaccess.h>
32 #include <asm/delay.h>
33 #include <asm/cpcmd.h>
34 #include <asm/setup.h>
35 
36 #include "ctrlchar.h"
37 
38 #define NR_3215		    1
39 #define NR_3215_REQ	    (4*NR_3215)
40 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
41 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
42 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
43 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
44 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
45 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
46 #define RAW3215_NR_CCWS	    3
47 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
48 
49 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
50 #define RAW3215_ACTIVE	    2	      /* set if the device is in use */
51 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
52 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
53 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
54 #define RAW3215_CLOSING	    32	      /* set while in close process */
55 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
56 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
57 
58 #define TAB_STOP_SIZE	    8	      /* tab stop size */
59 
60 /*
61  * Request types for a 3215 device
62  */
63 enum raw3215_type {
64 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
65 };
66 
67 /*
68  * Request structure for a 3215 device
69  */
70 struct raw3215_req {
71 	enum raw3215_type type;	      /* type of the request */
72 	int start, len;		      /* start index & len in output buffer */
73 	int delayable;		      /* indication to wait for more data */
74 	int residual;		      /* residual count for read request */
75 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
76 	struct raw3215_info *info;    /* pointer to main structure */
77 	struct raw3215_req *next;     /* pointer to next request */
78 } __attribute__ ((aligned(8)));
79 
80 struct raw3215_info {
81 	struct ccw_device *cdev;      /* device for tty driver */
82 	spinlock_t *lock;	      /* pointer to irq lock */
83 	int flags;		      /* state flags */
84 	char *buffer;		      /* pointer to output buffer */
85 	char *inbuf;		      /* pointer to input buffer */
86 	int head;		      /* first free byte in output buffer */
87 	int count;		      /* number of bytes in output buffer */
88 	int written;		      /* number of bytes in write requests */
89 	struct tty_struct *tty;	      /* pointer to tty structure if present */
90 	struct tasklet_struct tasklet;
91 	struct raw3215_req *queued_read; /* pointer to queued read requests */
92 	struct raw3215_req *queued_write;/* pointer to queued write requests */
93 	wait_queue_head_t empty_wait; /* wait queue for flushing */
94 	struct timer_list timer;      /* timer for delayed output */
95 	char *message;		      /* pending message from raw3215_irq */
96 	int msg_dstat;		      /* dstat for pending message */
97 	int msg_cstat;		      /* cstat for pending message */
98 	int line_pos;		      /* position on the line (for tabs) */
99 	char ubuffer[80];	      /* copy_from_user buffer */
100 };
101 
102 /* array of 3215 devices structures */
103 static struct raw3215_info *raw3215[NR_3215];
104 /* spinlock to protect the raw3215 array */
105 static DEFINE_SPINLOCK(raw3215_device_lock);
106 /* list of free request structures */
107 static struct raw3215_req *raw3215_freelist;
108 /* spinlock to protect free list */
109 static spinlock_t raw3215_freelist_lock;
110 
111 static struct tty_driver *tty3215_driver;
112 
113 /*
114  * Get a request structure from the free list
115  */
116 static inline struct raw3215_req *
117 raw3215_alloc_req(void) {
118 	struct raw3215_req *req;
119 	unsigned long flags;
120 
121 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
122 	req = raw3215_freelist;
123 	raw3215_freelist = req->next;
124 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
125 	return req;
126 }
127 
128 /*
129  * Put a request structure back to the free list
130  */
131 static inline void
132 raw3215_free_req(struct raw3215_req *req) {
133 	unsigned long flags;
134 
135 	if (req->type == RAW3215_FREE)
136 		return;		/* don't free a free request */
137 	req->type = RAW3215_FREE;
138 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
139 	req->next = raw3215_freelist;
140 	raw3215_freelist = req;
141 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
142 }
143 
144 /*
145  * Set up a read request that reads up to 160 byte from the 3215 device.
146  * If there is a queued read request it is used, but that shouldn't happen
147  * because a 3215 terminal won't accept a new read before the old one is
148  * completed.
149  */
150 static void
151 raw3215_mk_read_req(struct raw3215_info *raw)
152 {
153 	struct raw3215_req *req;
154 	struct ccw1 *ccw;
155 
156 	/* there can only be ONE read request at a time */
157 	req = raw->queued_read;
158 	if (req == NULL) {
159 		/* no queued read request, use new req structure */
160 		req = raw3215_alloc_req();
161 		req->type = RAW3215_READ;
162 		req->info = raw;
163 		raw->queued_read = req;
164 	}
165 
166 	ccw = req->ccws;
167 	ccw->cmd_code = 0x0A; /* read inquiry */
168 	ccw->flags = 0x20;    /* ignore incorrect length */
169 	ccw->count = 160;
170 	ccw->cda = (__u32) __pa(raw->inbuf);
171 }
172 
173 /*
174  * Set up a write request with the information from the main structure.
175  * A ccw chain is created that writes as much as possible from the output
176  * buffer to the 3215 device. If a queued write exists it is replaced by
177  * the new, probably lengthened request.
178  */
179 static void
180 raw3215_mk_write_req(struct raw3215_info *raw)
181 {
182 	struct raw3215_req *req;
183 	struct ccw1 *ccw;
184 	int len, count, ix, lines;
185 
186 	if (raw->count <= raw->written)
187 		return;
188 	/* check if there is a queued write request */
189 	req = raw->queued_write;
190 	if (req == NULL) {
191 		/* no queued write request, use new req structure */
192 		req = raw3215_alloc_req();
193 		req->type = RAW3215_WRITE;
194 		req->info = raw;
195 		raw->queued_write = req;
196 	} else {
197 		raw->written -= req->len;
198 	}
199 
200 	ccw = req->ccws;
201 	req->start = (raw->head - raw->count + raw->written) &
202 		     (RAW3215_BUFFER_SIZE - 1);
203 	/*
204 	 * now we have to count newlines. We can at max accept
205 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
206 	 * a restriction in VM
207 	 */
208 	lines = 0;
209 	ix = req->start;
210 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
211 		if (raw->buffer[ix] == 0x15)
212 			lines++;
213 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
214 	}
215 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
216 	if (len > RAW3215_MAX_BYTES)
217 		len = RAW3215_MAX_BYTES;
218 	req->len = len;
219 	raw->written += len;
220 
221 	/* set the indication if we should try to enlarge this request */
222 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
223 
224 	ix = req->start;
225 	while (len > 0) {
226 		if (ccw > req->ccws)
227 			ccw[-1].flags |= 0x40; /* use command chaining */
228 		ccw->cmd_code = 0x01; /* write, auto carrier return */
229 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
230 		ccw->cda =
231 			(__u32) __pa(raw->buffer + ix);
232 		count = len;
233 		if (ix + count > RAW3215_BUFFER_SIZE)
234 			count = RAW3215_BUFFER_SIZE - ix;
235 		ccw->count = count;
236 		len -= count;
237 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
238 		ccw++;
239 	}
240 	/*
241 	 * Add a NOP to the channel program. 3215 devices are purely
242 	 * emulated and its much better to avoid the channel end
243 	 * interrupt in this case.
244 	 */
245 	if (ccw > req->ccws)
246 		ccw[-1].flags |= 0x40; /* use command chaining */
247 	ccw->cmd_code = 0x03; /* NOP */
248 	ccw->flags = 0;
249 	ccw->cda = 0;
250 	ccw->count = 1;
251 }
252 
253 /*
254  * Start a read or a write request
255  */
256 static void
257 raw3215_start_io(struct raw3215_info *raw)
258 {
259 	struct raw3215_req *req;
260 	int res;
261 
262 	req = raw->queued_read;
263 	if (req != NULL &&
264 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
265 		/* dequeue request */
266 		raw->queued_read = NULL;
267 		res = ccw_device_start(raw->cdev, req->ccws,
268 				       (unsigned long) req, 0, 0);
269 		if (res != 0) {
270 			/* do_IO failed, put request back to queue */
271 			raw->queued_read = req;
272 		} else {
273 			raw->flags |= RAW3215_WORKING;
274 		}
275 	}
276 	req = raw->queued_write;
277 	if (req != NULL &&
278 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
279 		/* dequeue request */
280 		raw->queued_write = NULL;
281 		res = ccw_device_start(raw->cdev, req->ccws,
282 				       (unsigned long) req, 0, 0);
283 		if (res != 0) {
284 			/* do_IO failed, put request back to queue */
285 			raw->queued_write = req;
286 		} else {
287 			raw->flags |= RAW3215_WORKING;
288 		}
289 	}
290 }
291 
292 /*
293  * Function to start a delayed output after RAW3215_TIMEOUT seconds
294  */
295 static void
296 raw3215_timeout(unsigned long __data)
297 {
298 	struct raw3215_info *raw = (struct raw3215_info *) __data;
299 	unsigned long flags;
300 
301 	spin_lock_irqsave(raw->lock, flags);
302 	if (raw->flags & RAW3215_TIMER_RUNS) {
303 		del_timer(&raw->timer);
304 		raw->flags &= ~RAW3215_TIMER_RUNS;
305 		raw3215_mk_write_req(raw);
306 		raw3215_start_io(raw);
307 	}
308 	spin_unlock_irqrestore(raw->lock, flags);
309 }
310 
311 /*
312  * Function to conditionally start an IO. A read is started immediately,
313  * a write is only started immediately if the flush flag is on or the
314  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
315  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
316  */
317 static inline void
318 raw3215_try_io(struct raw3215_info *raw)
319 {
320 	if (!(raw->flags & RAW3215_ACTIVE))
321 		return;
322 	if (raw->queued_read != NULL)
323 		raw3215_start_io(raw);
324 	else if (raw->queued_write != NULL) {
325 		if ((raw->queued_write->delayable == 0) ||
326 		    (raw->flags & RAW3215_FLUSHING)) {
327 			/* execute write requests bigger than minimum size */
328 			raw3215_start_io(raw);
329 			if (raw->flags & RAW3215_TIMER_RUNS) {
330 				del_timer(&raw->timer);
331 				raw->flags &= ~RAW3215_TIMER_RUNS;
332 			}
333 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
334 			/* delay small writes */
335 			init_timer(&raw->timer);
336 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
337 			raw->timer.data = (unsigned long) raw;
338 			raw->timer.function = raw3215_timeout;
339 			add_timer(&raw->timer);
340 			raw->flags |= RAW3215_TIMER_RUNS;
341 		}
342 	}
343 }
344 
345 /*
346  * The bottom half handler routine for 3215 devices. It tries to start
347  * the next IO and wakes up processes waiting on the tty.
348  */
349 static void
350 raw3215_tasklet(void *data)
351 {
352 	struct raw3215_info *raw;
353 	struct tty_struct *tty;
354 	unsigned long flags;
355 
356 	raw = (struct raw3215_info *) data;
357 	spin_lock_irqsave(raw->lock, flags);
358 	raw3215_mk_write_req(raw);
359 	raw3215_try_io(raw);
360 	spin_unlock_irqrestore(raw->lock, flags);
361 	/* Check for pending message from raw3215_irq */
362 	if (raw->message != NULL) {
363 		printk(raw->message, raw->msg_dstat, raw->msg_cstat);
364 		raw->message = NULL;
365 	}
366 	tty = raw->tty;
367 	if (tty != NULL &&
368 	    RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
369 	    	tty_wakeup(tty);
370 	}
371 }
372 
373 /*
374  * Interrupt routine, called from common io layer
375  */
376 static void
377 raw3215_irq(struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
378 {
379 	struct raw3215_info *raw;
380 	struct raw3215_req *req;
381 	struct tty_struct *tty;
382 	int cstat, dstat;
383 	int count, slen;
384 
385 	raw = cdev->dev.driver_data;
386 	req = (struct raw3215_req *) intparm;
387 	cstat = irb->scsw.cstat;
388 	dstat = irb->scsw.dstat;
389 	if (cstat != 0) {
390 		raw->message = KERN_WARNING
391 			"Got nonzero channel status in raw3215_irq "
392 			"(dev sts 0x%2x, sch sts 0x%2x)";
393 		raw->msg_dstat = dstat;
394 		raw->msg_cstat = cstat;
395 		tasklet_schedule(&raw->tasklet);
396 	}
397 	if (dstat & 0x01) { /* we got a unit exception */
398 		dstat &= ~0x01;	 /* we can ignore it */
399 	}
400 	switch (dstat) {
401 	case 0x80:
402 		if (cstat != 0)
403 			break;
404 		/* Attention interrupt, someone hit the enter key */
405 		raw3215_mk_read_req(raw);
406 		if (MACHINE_IS_P390)
407 			memset(raw->inbuf, 0, RAW3215_INBUF_SIZE);
408 		tasklet_schedule(&raw->tasklet);
409 		break;
410 	case 0x08:
411 	case 0x0C:
412 		/* Channel end interrupt. */
413 		if ((raw = req->info) == NULL)
414 			return;		     /* That shouldn't happen ... */
415 		if (req->type == RAW3215_READ) {
416 			/* store residual count, then wait for device end */
417 			req->residual = irb->scsw.count;
418 		}
419 		if (dstat == 0x08)
420 			break;
421 	case 0x04:
422 		/* Device end interrupt. */
423 		if ((raw = req->info) == NULL)
424 			return;		     /* That shouldn't happen ... */
425 		if (req->type == RAW3215_READ && raw->tty != NULL) {
426 			unsigned int cchar;
427 
428 			tty = raw->tty;
429 			count = 160 - req->residual;
430 			if (MACHINE_IS_P390) {
431 				slen = strnlen(raw->inbuf, RAW3215_INBUF_SIZE);
432 				if (count > slen)
433 					count = slen;
434 			} else
435 			if (count >= TTY_FLIPBUF_SIZE - tty->flip.count)
436 				count = TTY_FLIPBUF_SIZE - tty->flip.count - 1;
437 			EBCASC(raw->inbuf, count);
438 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
439 			switch (cchar & CTRLCHAR_MASK) {
440 			case CTRLCHAR_SYSRQ:
441 				break;
442 
443 			case CTRLCHAR_CTRL:
444 				tty->flip.count++;
445 				*tty->flip.flag_buf_ptr++ = TTY_NORMAL;
446 				*tty->flip.char_buf_ptr++ = cchar;
447 				tty_flip_buffer_push(raw->tty);
448 				break;
449 
450 			case CTRLCHAR_NONE:
451 				memcpy(tty->flip.char_buf_ptr,
452 				       raw->inbuf, count);
453 				if (count < 2 ||
454 				    (strncmp(raw->inbuf+count-2, "^n", 2) &&
455 				    strncmp(raw->inbuf+count-2, "\252n", 2)) ) {
456 					/* don't add the auto \n */
457 					tty->flip.char_buf_ptr[count] = '\n';
458 					memset(tty->flip.flag_buf_ptr,
459 					       TTY_NORMAL, count + 1);
460 					count++;
461 				} else
462 					count-=2;
463 				tty->flip.char_buf_ptr += count;
464 				tty->flip.flag_buf_ptr += count;
465 				tty->flip.count += count;
466 				tty_flip_buffer_push(raw->tty);
467 				break;
468 			}
469 		} else if (req->type == RAW3215_WRITE) {
470 			raw->count -= req->len;
471 			raw->written -= req->len;
472 		}
473 		raw->flags &= ~RAW3215_WORKING;
474 		raw3215_free_req(req);
475 		/* check for empty wait */
476 		if (waitqueue_active(&raw->empty_wait) &&
477 		    raw->queued_write == NULL &&
478 		    raw->queued_read == NULL) {
479 			wake_up_interruptible(&raw->empty_wait);
480 		}
481 		tasklet_schedule(&raw->tasklet);
482 		break;
483 	default:
484 		/* Strange interrupt, I'll do my best to clean up */
485 		if (req != NULL && req->type != RAW3215_FREE) {
486 			if (req->type == RAW3215_WRITE) {
487 				raw->count -= req->len;
488 				raw->written -= req->len;
489 			}
490 			raw->flags &= ~RAW3215_WORKING;
491 			raw3215_free_req(req);
492 		}
493 		raw->message = KERN_WARNING
494 			"Spurious interrupt in in raw3215_irq "
495 			"(dev sts 0x%2x, sch sts 0x%2x)";
496 		raw->msg_dstat = dstat;
497 		raw->msg_cstat = cstat;
498 		tasklet_schedule(&raw->tasklet);
499 	}
500 	return;
501 }
502 
503 /*
504  * Wait until length bytes are available int the output buffer.
505  * Has to be called with the s390irq lock held. Can be called
506  * disabled.
507  */
508 static void
509 raw3215_make_room(struct raw3215_info *raw, unsigned int length)
510 {
511 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
512 		/* there might be a request pending */
513 		raw->flags |= RAW3215_FLUSHING;
514 		raw3215_mk_write_req(raw);
515 		raw3215_try_io(raw);
516 		raw->flags &= ~RAW3215_FLUSHING;
517 #ifdef CONFIG_TN3215_CONSOLE
518 		wait_cons_dev();
519 #endif
520 		/* Enough room freed up ? */
521 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
522 			break;
523 		/* there might be another cpu waiting for the lock */
524 		spin_unlock(raw->lock);
525 		udelay(100);
526 		spin_lock(raw->lock);
527 	}
528 }
529 
530 /*
531  * String write routine for 3215 devices
532  */
533 static void
534 raw3215_write(struct raw3215_info *raw, const char *str, unsigned int length)
535 {
536 	unsigned long flags;
537 	int c, count;
538 
539 	while (length > 0) {
540 		spin_lock_irqsave(raw->lock, flags);
541 		count = (length > RAW3215_BUFFER_SIZE) ?
542 					     RAW3215_BUFFER_SIZE : length;
543 		length -= count;
544 
545 		raw3215_make_room(raw, count);
546 
547 		/* copy string to output buffer and convert it to EBCDIC */
548 		while (1) {
549 			c = min_t(int, count,
550 				  min(RAW3215_BUFFER_SIZE - raw->count,
551 				      RAW3215_BUFFER_SIZE - raw->head));
552 			if (c <= 0)
553 				break;
554 			memcpy(raw->buffer + raw->head, str, c);
555 			ASCEBC(raw->buffer + raw->head, c);
556 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
557 			raw->count += c;
558 			raw->line_pos += c;
559 			str += c;
560 			count -= c;
561 		}
562 		if (!(raw->flags & RAW3215_WORKING)) {
563 			raw3215_mk_write_req(raw);
564 			/* start or queue request */
565 			raw3215_try_io(raw);
566 		}
567 		spin_unlock_irqrestore(raw->lock, flags);
568 	}
569 }
570 
571 /*
572  * Put character routine for 3215 devices
573  */
574 static void
575 raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
576 {
577 	unsigned long flags;
578 	unsigned int length, i;
579 
580 	spin_lock_irqsave(raw->lock, flags);
581 	if (ch == '\t') {
582 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
583 		raw->line_pos += length;
584 		ch = ' ';
585 	} else if (ch == '\n') {
586 		length = 1;
587 		raw->line_pos = 0;
588 	} else {
589 		length = 1;
590 		raw->line_pos++;
591 	}
592 	raw3215_make_room(raw, length);
593 
594 	for (i = 0; i < length; i++) {
595 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
596 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
597 		raw->count++;
598 	}
599 	if (!(raw->flags & RAW3215_WORKING)) {
600 		raw3215_mk_write_req(raw);
601 		/* start or queue request */
602 		raw3215_try_io(raw);
603 	}
604 	spin_unlock_irqrestore(raw->lock, flags);
605 }
606 
607 /*
608  * Flush routine, it simply sets the flush flag and tries to start
609  * pending IO.
610  */
611 static void
612 raw3215_flush_buffer(struct raw3215_info *raw)
613 {
614 	unsigned long flags;
615 
616 	spin_lock_irqsave(raw->lock, flags);
617 	if (raw->count > 0) {
618 		raw->flags |= RAW3215_FLUSHING;
619 		raw3215_try_io(raw);
620 		raw->flags &= ~RAW3215_FLUSHING;
621 	}
622 	spin_unlock_irqrestore(raw->lock, flags);
623 }
624 
625 /*
626  * Fire up a 3215 device.
627  */
628 static int
629 raw3215_startup(struct raw3215_info *raw)
630 {
631 	unsigned long flags;
632 
633 	if (raw->flags & RAW3215_ACTIVE)
634 		return 0;
635 	raw->line_pos = 0;
636 	raw->flags |= RAW3215_ACTIVE;
637 	spin_lock_irqsave(raw->lock, flags);
638 	raw3215_try_io(raw);
639 	spin_unlock_irqrestore(raw->lock, flags);
640 
641 	return 0;
642 }
643 
644 /*
645  * Shutdown a 3215 device.
646  */
647 static void
648 raw3215_shutdown(struct raw3215_info *raw)
649 {
650 	DECLARE_WAITQUEUE(wait, current);
651 	unsigned long flags;
652 
653 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FIXED))
654 		return;
655 	/* Wait for outstanding requests, then free irq */
656 	spin_lock_irqsave(raw->lock, flags);
657 	if ((raw->flags & RAW3215_WORKING) ||
658 	    raw->queued_write != NULL ||
659 	    raw->queued_read != NULL) {
660 		raw->flags |= RAW3215_CLOSING;
661 		add_wait_queue(&raw->empty_wait, &wait);
662 		set_current_state(TASK_INTERRUPTIBLE);
663 		spin_unlock_irqrestore(raw->lock, flags);
664 		schedule();
665 		spin_lock_irqsave(raw->lock, flags);
666 		remove_wait_queue(&raw->empty_wait, &wait);
667 		set_current_state(TASK_RUNNING);
668 		raw->flags &= ~(RAW3215_ACTIVE | RAW3215_CLOSING);
669 	}
670 	spin_unlock_irqrestore(raw->lock, flags);
671 }
672 
673 static int
674 raw3215_probe (struct ccw_device *cdev)
675 {
676 	struct raw3215_info *raw;
677 	int line;
678 
679 	raw = kmalloc(sizeof(struct raw3215_info) +
680 		      RAW3215_INBUF_SIZE, GFP_KERNEL|GFP_DMA);
681 	if (raw == NULL)
682 		return -ENOMEM;
683 
684 	spin_lock(&raw3215_device_lock);
685 	for (line = 0; line < NR_3215; line++) {
686 		if (!raw3215[line]) {
687 			raw3215[line] = raw;
688 			break;
689 		}
690 	}
691 	spin_unlock(&raw3215_device_lock);
692 	if (line == NR_3215) {
693 		kfree(raw);
694 		return -ENODEV;
695 	}
696 
697 	raw->cdev = cdev;
698 	raw->lock = get_ccwdev_lock(cdev);
699 	raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
700 	memset(raw, 0, sizeof(struct raw3215_info));
701 	raw->buffer = (char *) kmalloc(RAW3215_BUFFER_SIZE,
702 				       GFP_KERNEL|GFP_DMA);
703 	if (raw->buffer == NULL) {
704 		spin_lock(&raw3215_device_lock);
705 		raw3215[line] = 0;
706 		spin_unlock(&raw3215_device_lock);
707 		kfree(raw);
708 		return -ENOMEM;
709 	}
710 	tasklet_init(&raw->tasklet,
711 		     (void (*)(unsigned long)) raw3215_tasklet,
712 		     (unsigned long) raw);
713 	init_waitqueue_head(&raw->empty_wait);
714 
715 	cdev->dev.driver_data = raw;
716 	cdev->handler = raw3215_irq;
717 
718 	return 0;
719 }
720 
721 static void
722 raw3215_remove (struct ccw_device *cdev)
723 {
724 	struct raw3215_info *raw;
725 
726 	ccw_device_set_offline(cdev);
727 	raw = cdev->dev.driver_data;
728 	if (raw) {
729 		cdev->dev.driver_data = NULL;
730 		kfree(raw->buffer);
731 		kfree(raw);
732 	}
733 }
734 
735 static int
736 raw3215_set_online (struct ccw_device *cdev)
737 {
738 	struct raw3215_info *raw;
739 
740 	raw = cdev->dev.driver_data;
741 	if (!raw)
742 		return -ENODEV;
743 
744 	return raw3215_startup(raw);
745 }
746 
747 static int
748 raw3215_set_offline (struct ccw_device *cdev)
749 {
750 	struct raw3215_info *raw;
751 
752 	raw = cdev->dev.driver_data;
753 	if (!raw)
754 		return -ENODEV;
755 
756 	raw3215_shutdown(raw);
757 
758 	return 0;
759 }
760 
761 static struct ccw_device_id raw3215_id[] = {
762 	{ CCW_DEVICE(0x3215, 0) },
763 	{ /* end of list */ },
764 };
765 
766 static struct ccw_driver raw3215_ccw_driver = {
767 	.name		= "3215",
768 	.owner		= THIS_MODULE,
769 	.ids		= raw3215_id,
770 	.probe		= &raw3215_probe,
771 	.remove		= &raw3215_remove,
772 	.set_online	= &raw3215_set_online,
773 	.set_offline	= &raw3215_set_offline,
774 };
775 
776 #ifdef CONFIG_TN3215_CONSOLE
777 /*
778  * Write a string to the 3215 console
779  */
780 static void
781 con3215_write(struct console *co, const char *str, unsigned int count)
782 {
783 	struct raw3215_info *raw;
784 	int i;
785 
786 	if (count <= 0)
787 		return;
788 	raw = raw3215[0];	/* console 3215 is the first one */
789 	while (count > 0) {
790 		for (i = 0; i < count; i++)
791 			if (str[i] == '\t' || str[i] == '\n')
792 				break;
793 		raw3215_write(raw, str, i);
794 		count -= i;
795 		str += i;
796 		if (count > 0) {
797 			raw3215_putchar(raw, *str);
798 			count--;
799 			str++;
800 		}
801 	}
802 }
803 
804 static struct tty_driver *con3215_device(struct console *c, int *index)
805 {
806 	*index = c->index;
807 	return tty3215_driver;
808 }
809 
810 /*
811  * panic() calls console_unblank before the system enters a
812  * disabled, endless loop.
813  */
814 static void
815 con3215_unblank(void)
816 {
817 	struct raw3215_info *raw;
818 	unsigned long flags;
819 
820 	raw = raw3215[0];  /* console 3215 is the first one */
821 	spin_lock_irqsave(raw->lock, flags);
822 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
823 	spin_unlock_irqrestore(raw->lock, flags);
824 }
825 
826 static int __init
827 con3215_consetup(struct console *co, char *options)
828 {
829 	return 0;
830 }
831 
832 /*
833  *  The console structure for the 3215 console
834  */
835 static struct console con3215 = {
836 	.name	 = "ttyS",
837 	.write	 = con3215_write,
838 	.device	 = con3215_device,
839 	.unblank = con3215_unblank,
840 	.setup	 = con3215_consetup,
841 	.flags	 = CON_PRINTBUFFER,
842 };
843 
844 /*
845  * 3215 console initialization code called from console_init().
846  * NOTE: This is called before kmalloc is available.
847  */
848 static int __init
849 con3215_init(void)
850 {
851 	struct ccw_device *cdev;
852 	struct raw3215_info *raw;
853 	struct raw3215_req *req;
854 	int i;
855 
856 	/* Check if 3215 is to be the console */
857 	if (!CONSOLE_IS_3215)
858 		return -ENODEV;
859 
860 	/* Set the console mode for VM */
861 	if (MACHINE_IS_VM) {
862 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
863 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
864 	}
865 
866 	/* allocate 3215 request structures */
867 	raw3215_freelist = NULL;
868 	spin_lock_init(&raw3215_freelist_lock);
869 	for (i = 0; i < NR_3215_REQ; i++) {
870 		req = (struct raw3215_req *) alloc_bootmem_low(sizeof(struct raw3215_req));
871 		req->next = raw3215_freelist;
872 		raw3215_freelist = req;
873 	}
874 
875 	cdev = ccw_device_probe_console();
876 	if (!cdev)
877 		return -ENODEV;
878 
879 	raw3215[0] = raw = (struct raw3215_info *)
880 		alloc_bootmem_low(sizeof(struct raw3215_info));
881 	memset(raw, 0, sizeof(struct raw3215_info));
882 	raw->buffer = (char *) alloc_bootmem_low(RAW3215_BUFFER_SIZE);
883 	raw->inbuf = (char *) alloc_bootmem_low(RAW3215_INBUF_SIZE);
884 	raw->cdev = cdev;
885 	raw->lock = get_ccwdev_lock(cdev);
886 	cdev->dev.driver_data = raw;
887 	cdev->handler = raw3215_irq;
888 
889 	raw->flags |= RAW3215_FIXED;
890 	tasklet_init(&raw->tasklet,
891 		     (void (*)(unsigned long)) raw3215_tasklet,
892 		     (unsigned long) raw);
893 	init_waitqueue_head(&raw->empty_wait);
894 
895 	/* Request the console irq */
896 	if (raw3215_startup(raw) != 0) {
897 		free_bootmem((unsigned long) raw->inbuf, RAW3215_INBUF_SIZE);
898 		free_bootmem((unsigned long) raw->buffer, RAW3215_BUFFER_SIZE);
899 		free_bootmem((unsigned long) raw, sizeof(struct raw3215_info));
900 		raw3215[0] = NULL;
901 		printk("Couldn't find a 3215 console device\n");
902 		return -ENODEV;
903 	}
904 	register_console(&con3215);
905 	return 0;
906 }
907 console_initcall(con3215_init);
908 #endif
909 
910 /*
911  * tty3215_open
912  *
913  * This routine is called whenever a 3215 tty is opened.
914  */
915 static int
916 tty3215_open(struct tty_struct *tty, struct file * filp)
917 {
918 	struct raw3215_info *raw;
919 	int retval, line;
920 
921 	line = tty->index;
922 	if ((line < 0) || (line >= NR_3215))
923 		return -ENODEV;
924 
925 	raw = raw3215[line];
926 	if (raw == NULL)
927 		return -ENODEV;
928 
929 	tty->driver_data = raw;
930 	raw->tty = tty;
931 
932 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
933 	/*
934 	 * Start up 3215 device
935 	 */
936 	retval = raw3215_startup(raw);
937 	if (retval)
938 		return retval;
939 
940 	return 0;
941 }
942 
943 /*
944  * tty3215_close()
945  *
946  * This routine is called when the 3215 tty is closed. We wait
947  * for the remaining request to be completed. Then we clean up.
948  */
949 static void
950 tty3215_close(struct tty_struct *tty, struct file * filp)
951 {
952 	struct raw3215_info *raw;
953 
954 	raw = (struct raw3215_info *) tty->driver_data;
955 	if (raw == NULL || tty->count > 1)
956 		return;
957 	tty->closing = 1;
958 	/* Shutdown the terminal */
959 	raw3215_shutdown(raw);
960 	tty->closing = 0;
961 	raw->tty = NULL;
962 }
963 
964 /*
965  * Returns the amount of free space in the output buffer.
966  */
967 static int
968 tty3215_write_room(struct tty_struct *tty)
969 {
970 	struct raw3215_info *raw;
971 
972 	raw = (struct raw3215_info *) tty->driver_data;
973 
974 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
975 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
976 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
977 	else
978 		return 0;
979 }
980 
981 /*
982  * String write routine for 3215 ttys
983  */
984 static int
985 tty3215_write(struct tty_struct * tty,
986 	      const unsigned char *buf, int count)
987 {
988 	struct raw3215_info *raw;
989 
990 	if (!tty)
991 		return 0;
992 	raw = (struct raw3215_info *) tty->driver_data;
993 	raw3215_write(raw, buf, count);
994 	return count;
995 }
996 
997 /*
998  * Put character routine for 3215 ttys
999  */
1000 static void
1001 tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1002 {
1003 	struct raw3215_info *raw;
1004 
1005 	if (!tty)
1006 		return;
1007 	raw = (struct raw3215_info *) tty->driver_data;
1008 	raw3215_putchar(raw, ch);
1009 }
1010 
1011 static void
1012 tty3215_flush_chars(struct tty_struct *tty)
1013 {
1014 }
1015 
1016 /*
1017  * Returns the number of characters in the output buffer
1018  */
1019 static int
1020 tty3215_chars_in_buffer(struct tty_struct *tty)
1021 {
1022 	struct raw3215_info *raw;
1023 
1024 	raw = (struct raw3215_info *) tty->driver_data;
1025 	return raw->count;
1026 }
1027 
1028 static void
1029 tty3215_flush_buffer(struct tty_struct *tty)
1030 {
1031 	struct raw3215_info *raw;
1032 
1033 	raw = (struct raw3215_info *) tty->driver_data;
1034 	raw3215_flush_buffer(raw);
1035 	tty_wakeup(tty);
1036 }
1037 
1038 /*
1039  * Currently we don't have any io controls for 3215 ttys
1040  */
1041 static int
1042 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
1059 tty3215_throttle(struct tty_struct * tty)
1060 {
1061 	struct raw3215_info *raw;
1062 
1063 	raw = (struct raw3215_info *) tty->driver_data;
1064 	raw->flags |= RAW3215_THROTTLED;
1065 }
1066 
1067 /*
1068  * Enable reading from a 3215 tty
1069  */
1070 static void
1071 tty3215_unthrottle(struct tty_struct * tty)
1072 {
1073 	struct raw3215_info *raw;
1074 	unsigned long flags;
1075 
1076 	raw = (struct raw3215_info *) tty->driver_data;
1077 	if (raw->flags & RAW3215_THROTTLED) {
1078 		spin_lock_irqsave(raw->lock, flags);
1079 		raw->flags &= ~RAW3215_THROTTLED;
1080 		raw3215_try_io(raw);
1081 		spin_unlock_irqrestore(raw->lock, flags);
1082 	}
1083 }
1084 
1085 /*
1086  * Disable writing to a 3215 tty
1087  */
1088 static void
1089 tty3215_stop(struct tty_struct *tty)
1090 {
1091 	struct raw3215_info *raw;
1092 
1093 	raw = (struct raw3215_info *) tty->driver_data;
1094 	raw->flags |= RAW3215_STOPPED;
1095 }
1096 
1097 /*
1098  * Enable writing to a 3215 tty
1099  */
1100 static void
1101 tty3215_start(struct tty_struct *tty)
1102 {
1103 	struct raw3215_info *raw;
1104 	unsigned long flags;
1105 
1106 	raw = (struct raw3215_info *) tty->driver_data;
1107 	if (raw->flags & RAW3215_STOPPED) {
1108 		spin_lock_irqsave(raw->lock, flags);
1109 		raw->flags &= ~RAW3215_STOPPED;
1110 		raw3215_try_io(raw);
1111 		spin_unlock_irqrestore(raw->lock, flags);
1112 	}
1113 }
1114 
1115 static struct tty_operations tty3215_ops = {
1116 	.open = tty3215_open,
1117 	.close = tty3215_close,
1118 	.write = tty3215_write,
1119 	.put_char = tty3215_put_char,
1120 	.flush_chars = tty3215_flush_chars,
1121 	.write_room = tty3215_write_room,
1122 	.chars_in_buffer = tty3215_chars_in_buffer,
1123 	.flush_buffer = tty3215_flush_buffer,
1124 	.ioctl = tty3215_ioctl,
1125 	.throttle = tty3215_throttle,
1126 	.unthrottle = tty3215_unthrottle,
1127 	.stop = tty3215_stop,
1128 	.start = tty3215_start,
1129 };
1130 
1131 /*
1132  * 3215 tty registration code called from tty_init().
1133  * Most kernel services (incl. kmalloc) are available at this poimt.
1134  */
1135 int __init
1136 tty3215_init(void)
1137 {
1138 	struct tty_driver *driver;
1139 	int ret;
1140 
1141 	if (!CONSOLE_IS_3215)
1142 		return 0;
1143 
1144 	driver = alloc_tty_driver(NR_3215);
1145 	if (!driver)
1146 		return -ENOMEM;
1147 
1148 	ret = ccw_driver_register(&raw3215_ccw_driver);
1149 	if (ret) {
1150 		put_tty_driver(driver);
1151 		return ret;
1152 	}
1153 	/*
1154 	 * Initialize the tty_driver structure
1155 	 * Entries in tty3215_driver that are NOT initialized:
1156 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1157 	 */
1158 
1159 	driver->owner = THIS_MODULE;
1160 	driver->driver_name = "tty3215";
1161 	driver->name = "ttyS";
1162 	driver->major = TTY_MAJOR;
1163 	driver->minor_start = 64;
1164 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1165 	driver->subtype = SYSTEM_TYPE_TTY;
1166 	driver->init_termios = tty_std_termios;
1167 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1168 	driver->init_termios.c_oflag = ONLCR | XTABS;
1169 	driver->init_termios.c_lflag = ISIG;
1170 	driver->flags = TTY_DRIVER_REAL_RAW;
1171 	tty_set_operations(driver, &tty3215_ops);
1172 	ret = tty_register_driver(driver);
1173 	if (ret) {
1174 		printk("Couldn't register tty3215 driver\n");
1175 		put_tty_driver(driver);
1176 		return ret;
1177 	}
1178 	tty3215_driver = driver;
1179 	return 0;
1180 }
1181 
1182 static void __exit
1183 tty3215_exit(void)
1184 {
1185 	tty_unregister_driver(tty3215_driver);
1186 	put_tty_driver(tty3215_driver);
1187 	ccw_driver_unregister(&raw3215_ccw_driver);
1188 }
1189 
1190 module_init(tty3215_init);
1191 module_exit(tty3215_exit);
1192