xref: /openbmc/linux/drivers/s390/char/con3215.c (revision 384740dc)
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/module.h>
15 #include <linux/types.h>
16 #include <linux/kdev_t.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/vt_kern.h>
20 #include <linux/init.h>
21 #include <linux/console.h>
22 #include <linux/interrupt.h>
23 #include <linux/err.h>
24 
25 #include <linux/slab.h>
26 #include <linux/bootmem.h>
27 
28 #include <asm/ccwdev.h>
29 #include <asm/cio.h>
30 #include <asm/io.h>
31 #include <asm/ebcdic.h>
32 #include <asm/uaccess.h>
33 #include <asm/delay.h>
34 #include <asm/cpcmd.h>
35 #include <asm/setup.h>
36 
37 #include "ctrlchar.h"
38 
39 #define NR_3215		    1
40 #define NR_3215_REQ	    (4*NR_3215)
41 #define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
42 #define RAW3215_INBUF_SIZE  256	      /* input buffer size */
43 #define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
44 #define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
45 #define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
46 #define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
47 #define RAW3215_NR_CCWS	    3
48 #define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */
49 
50 #define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
51 #define RAW3215_ACTIVE	    2	      /* set if the device is in use */
52 #define RAW3215_WORKING	    4	      /* set if a request is being worked on */
53 #define RAW3215_THROTTLED   8	      /* set if reading is disabled */
54 #define RAW3215_STOPPED	    16	      /* set if writing is disabled */
55 #define RAW3215_CLOSING	    32	      /* set while in close process */
56 #define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
57 #define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */
58 
59 #define TAB_STOP_SIZE	    8	      /* tab stop size */
60 
61 /*
62  * Request types for a 3215 device
63  */
64 enum raw3215_type {
65 	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
66 };
67 
68 /*
69  * Request structure for a 3215 device
70  */
71 struct raw3215_req {
72 	enum raw3215_type type;	      /* type of the request */
73 	int start, len;		      /* start index & len in output buffer */
74 	int delayable;		      /* indication to wait for more data */
75 	int residual;		      /* residual count for read request */
76 	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
77 	struct raw3215_info *info;    /* pointer to main structure */
78 	struct raw3215_req *next;     /* pointer to next request */
79 } __attribute__ ((aligned(8)));
80 
81 struct raw3215_info {
82 	struct ccw_device *cdev;      /* device for tty driver */
83 	spinlock_t *lock;	      /* pointer to irq lock */
84 	int flags;		      /* state flags */
85 	char *buffer;		      /* pointer to output buffer */
86 	char *inbuf;		      /* pointer to input buffer */
87 	int head;		      /* first free byte in output buffer */
88 	int count;		      /* number of bytes in output buffer */
89 	int written;		      /* number of bytes in write requests */
90 	struct tty_struct *tty;	      /* pointer to tty structure if present */
91 	struct tasklet_struct tasklet;
92 	struct raw3215_req *queued_read; /* pointer to queued read requests */
93 	struct raw3215_req *queued_write;/* pointer to queued write requests */
94 	wait_queue_head_t empty_wait; /* wait queue for flushing */
95 	struct timer_list timer;      /* timer for delayed output */
96 	int line_pos;		      /* position on the line (for tabs) */
97 	char ubuffer[80];	      /* copy_from_user buffer */
98 };
99 
100 /* array of 3215 devices structures */
101 static struct raw3215_info *raw3215[NR_3215];
102 /* spinlock to protect the raw3215 array */
103 static DEFINE_SPINLOCK(raw3215_device_lock);
104 /* list of free request structures */
105 static struct raw3215_req *raw3215_freelist;
106 /* spinlock to protect free list */
107 static spinlock_t raw3215_freelist_lock;
108 
109 static struct tty_driver *tty3215_driver;
110 
111 /*
112  * Get a request structure from the free list
113  */
114 static inline struct raw3215_req *
115 raw3215_alloc_req(void) {
116 	struct raw3215_req *req;
117 	unsigned long flags;
118 
119 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
120 	req = raw3215_freelist;
121 	raw3215_freelist = req->next;
122 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
123 	return req;
124 }
125 
126 /*
127  * Put a request structure back to the free list
128  */
129 static inline void
130 raw3215_free_req(struct raw3215_req *req) {
131 	unsigned long flags;
132 
133 	if (req->type == RAW3215_FREE)
134 		return;		/* don't free a free request */
135 	req->type = RAW3215_FREE;
136 	spin_lock_irqsave(&raw3215_freelist_lock, flags);
137 	req->next = raw3215_freelist;
138 	raw3215_freelist = req;
139 	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
140 }
141 
142 /*
143  * Set up a read request that reads up to 160 byte from the 3215 device.
144  * If there is a queued read request it is used, but that shouldn't happen
145  * because a 3215 terminal won't accept a new read before the old one is
146  * completed.
147  */
148 static void
149 raw3215_mk_read_req(struct raw3215_info *raw)
150 {
151 	struct raw3215_req *req;
152 	struct ccw1 *ccw;
153 
154 	/* there can only be ONE read request at a time */
155 	req = raw->queued_read;
156 	if (req == NULL) {
157 		/* no queued read request, use new req structure */
158 		req = raw3215_alloc_req();
159 		req->type = RAW3215_READ;
160 		req->info = raw;
161 		raw->queued_read = req;
162 	}
163 
164 	ccw = req->ccws;
165 	ccw->cmd_code = 0x0A; /* read inquiry */
166 	ccw->flags = 0x20;    /* ignore incorrect length */
167 	ccw->count = 160;
168 	ccw->cda = (__u32) __pa(raw->inbuf);
169 }
170 
171 /*
172  * Set up a write request with the information from the main structure.
173  * A ccw chain is created that writes as much as possible from the output
174  * buffer to the 3215 device. If a queued write exists it is replaced by
175  * the new, probably lengthened request.
176  */
177 static void
178 raw3215_mk_write_req(struct raw3215_info *raw)
179 {
180 	struct raw3215_req *req;
181 	struct ccw1 *ccw;
182 	int len, count, ix, lines;
183 
184 	if (raw->count <= raw->written)
185 		return;
186 	/* check if there is a queued write request */
187 	req = raw->queued_write;
188 	if (req == NULL) {
189 		/* no queued write request, use new req structure */
190 		req = raw3215_alloc_req();
191 		req->type = RAW3215_WRITE;
192 		req->info = raw;
193 		raw->queued_write = req;
194 	} else {
195 		raw->written -= req->len;
196 	}
197 
198 	ccw = req->ccws;
199 	req->start = (raw->head - raw->count + raw->written) &
200 		     (RAW3215_BUFFER_SIZE - 1);
201 	/*
202 	 * now we have to count newlines. We can at max accept
203 	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
204 	 * a restriction in VM
205 	 */
206 	lines = 0;
207 	ix = req->start;
208 	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
209 		if (raw->buffer[ix] == 0x15)
210 			lines++;
211 		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
212 	}
213 	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
214 	if (len > RAW3215_MAX_BYTES)
215 		len = RAW3215_MAX_BYTES;
216 	req->len = len;
217 	raw->written += len;
218 
219 	/* set the indication if we should try to enlarge this request */
220 	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
221 
222 	ix = req->start;
223 	while (len > 0) {
224 		if (ccw > req->ccws)
225 			ccw[-1].flags |= 0x40; /* use command chaining */
226 		ccw->cmd_code = 0x01; /* write, auto carrier return */
227 		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
228 		ccw->cda =
229 			(__u32) __pa(raw->buffer + ix);
230 		count = len;
231 		if (ix + count > RAW3215_BUFFER_SIZE)
232 			count = RAW3215_BUFFER_SIZE - ix;
233 		ccw->count = count;
234 		len -= count;
235 		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
236 		ccw++;
237 	}
238 	/*
239 	 * Add a NOP to the channel program. 3215 devices are purely
240 	 * emulated and its much better to avoid the channel end
241 	 * interrupt in this case.
242 	 */
243 	if (ccw > req->ccws)
244 		ccw[-1].flags |= 0x40; /* use command chaining */
245 	ccw->cmd_code = 0x03; /* NOP */
246 	ccw->flags = 0;
247 	ccw->cda = 0;
248 	ccw->count = 1;
249 }
250 
251 /*
252  * Start a read or a write request
253  */
254 static void
255 raw3215_start_io(struct raw3215_info *raw)
256 {
257 	struct raw3215_req *req;
258 	int res;
259 
260 	req = raw->queued_read;
261 	if (req != NULL &&
262 	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
263 		/* dequeue request */
264 		raw->queued_read = NULL;
265 		res = ccw_device_start(raw->cdev, req->ccws,
266 				       (unsigned long) req, 0, 0);
267 		if (res != 0) {
268 			/* do_IO failed, put request back to queue */
269 			raw->queued_read = req;
270 		} else {
271 			raw->flags |= RAW3215_WORKING;
272 		}
273 	}
274 	req = raw->queued_write;
275 	if (req != NULL &&
276 	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
277 		/* dequeue request */
278 		raw->queued_write = NULL;
279 		res = ccw_device_start(raw->cdev, req->ccws,
280 				       (unsigned long) req, 0, 0);
281 		if (res != 0) {
282 			/* do_IO failed, put request back to queue */
283 			raw->queued_write = req;
284 		} else {
285 			raw->flags |= RAW3215_WORKING;
286 		}
287 	}
288 }
289 
290 /*
291  * Function to start a delayed output after RAW3215_TIMEOUT seconds
292  */
293 static void
294 raw3215_timeout(unsigned long __data)
295 {
296 	struct raw3215_info *raw = (struct raw3215_info *) __data;
297 	unsigned long flags;
298 
299 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
300 	if (raw->flags & RAW3215_TIMER_RUNS) {
301 		del_timer(&raw->timer);
302 		raw->flags &= ~RAW3215_TIMER_RUNS;
303 		raw3215_mk_write_req(raw);
304 		raw3215_start_io(raw);
305 	}
306 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
307 }
308 
309 /*
310  * Function to conditionally start an IO. A read is started immediately,
311  * a write is only started immediately if the flush flag is on or the
312  * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
313  * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
314  */
315 static inline void
316 raw3215_try_io(struct raw3215_info *raw)
317 {
318 	if (!(raw->flags & RAW3215_ACTIVE))
319 		return;
320 	if (raw->queued_read != NULL)
321 		raw3215_start_io(raw);
322 	else if (raw->queued_write != NULL) {
323 		if ((raw->queued_write->delayable == 0) ||
324 		    (raw->flags & RAW3215_FLUSHING)) {
325 			/* execute write requests bigger than minimum size */
326 			raw3215_start_io(raw);
327 			if (raw->flags & RAW3215_TIMER_RUNS) {
328 				del_timer(&raw->timer);
329 				raw->flags &= ~RAW3215_TIMER_RUNS;
330 			}
331 		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
332 			/* delay small writes */
333 			init_timer(&raw->timer);
334 			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
335 			raw->timer.data = (unsigned long) raw;
336 			raw->timer.function = raw3215_timeout;
337 			add_timer(&raw->timer);
338 			raw->flags |= RAW3215_TIMER_RUNS;
339 		}
340 	}
341 }
342 
343 /*
344  * The bottom half handler routine for 3215 devices. It tries to start
345  * the next IO and wakes up processes waiting on the tty.
346  */
347 static void
348 raw3215_tasklet(void *data)
349 {
350 	struct raw3215_info *raw;
351 	struct tty_struct *tty;
352 	unsigned long flags;
353 
354 	raw = (struct raw3215_info *) data;
355 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
356 	raw3215_mk_write_req(raw);
357 	raw3215_try_io(raw);
358 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
359 	tty = raw->tty;
360 	if (tty != NULL &&
361 	    RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
362 	    	tty_wakeup(tty);
363 	}
364 }
365 
366 /*
367  * Interrupt routine, called from common io layer
368  */
369 static void
370 raw3215_irq(struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
371 {
372 	struct raw3215_info *raw;
373 	struct raw3215_req *req;
374 	struct tty_struct *tty;
375 	int cstat, dstat;
376 	int count;
377 
378 	raw = cdev->dev.driver_data;
379 	req = (struct raw3215_req *) intparm;
380 	cstat = irb->scsw.cmd.cstat;
381 	dstat = irb->scsw.cmd.dstat;
382 	if (cstat != 0)
383 		tasklet_schedule(&raw->tasklet);
384 	if (dstat & 0x01) { /* we got a unit exception */
385 		dstat &= ~0x01;	 /* we can ignore it */
386 	}
387 	switch (dstat) {
388 	case 0x80:
389 		if (cstat != 0)
390 			break;
391 		/* Attention interrupt, someone hit the enter key */
392 		raw3215_mk_read_req(raw);
393 		tasklet_schedule(&raw->tasklet);
394 		break;
395 	case 0x08:
396 	case 0x0C:
397 		/* Channel end interrupt. */
398 		if ((raw = req->info) == NULL)
399 			return;		     /* That shouldn't happen ... */
400 		if (req->type == RAW3215_READ) {
401 			/* store residual count, then wait for device end */
402 			req->residual = irb->scsw.cmd.count;
403 		}
404 		if (dstat == 0x08)
405 			break;
406 	case 0x04:
407 		/* Device end interrupt. */
408 		if ((raw = req->info) == NULL)
409 			return;		     /* That shouldn't happen ... */
410 		if (req->type == RAW3215_READ && raw->tty != NULL) {
411 			unsigned int cchar;
412 
413 			tty = raw->tty;
414 			count = 160 - req->residual;
415 			EBCASC(raw->inbuf, count);
416 			cchar = ctrlchar_handle(raw->inbuf, count, tty);
417 			switch (cchar & CTRLCHAR_MASK) {
418 			case CTRLCHAR_SYSRQ:
419 				break;
420 
421 			case CTRLCHAR_CTRL:
422 				tty_insert_flip_char(tty, cchar, TTY_NORMAL);
423 				tty_flip_buffer_push(raw->tty);
424 				break;
425 
426 			case CTRLCHAR_NONE:
427 				if (count < 2 ||
428 				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
429 				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
430 					/* add the auto \n */
431 					raw->inbuf[count] = '\n';
432 					count++;
433 				} else
434 					count -= 2;
435 				tty_insert_flip_string(tty, raw->inbuf, count);
436 				tty_flip_buffer_push(raw->tty);
437 				break;
438 			}
439 		} else if (req->type == RAW3215_WRITE) {
440 			raw->count -= req->len;
441 			raw->written -= req->len;
442 		}
443 		raw->flags &= ~RAW3215_WORKING;
444 		raw3215_free_req(req);
445 		/* check for empty wait */
446 		if (waitqueue_active(&raw->empty_wait) &&
447 		    raw->queued_write == NULL &&
448 		    raw->queued_read == NULL) {
449 			wake_up_interruptible(&raw->empty_wait);
450 		}
451 		tasklet_schedule(&raw->tasklet);
452 		break;
453 	default:
454 		/* Strange interrupt, I'll do my best to clean up */
455 		if (req != NULL && req->type != RAW3215_FREE) {
456 			if (req->type == RAW3215_WRITE) {
457 				raw->count -= req->len;
458 				raw->written -= req->len;
459 			}
460 			raw->flags &= ~RAW3215_WORKING;
461 			raw3215_free_req(req);
462 		}
463 		tasklet_schedule(&raw->tasklet);
464 	}
465 	return;
466 }
467 
468 /*
469  * Wait until length bytes are available int the output buffer.
470  * Has to be called with the s390irq lock held. Can be called
471  * disabled.
472  */
473 static void
474 raw3215_make_room(struct raw3215_info *raw, unsigned int length)
475 {
476 	while (RAW3215_BUFFER_SIZE - raw->count < length) {
477 		/* there might be a request pending */
478 		raw->flags |= RAW3215_FLUSHING;
479 		raw3215_mk_write_req(raw);
480 		raw3215_try_io(raw);
481 		raw->flags &= ~RAW3215_FLUSHING;
482 #ifdef CONFIG_TN3215_CONSOLE
483 		wait_cons_dev();
484 #endif
485 		/* Enough room freed up ? */
486 		if (RAW3215_BUFFER_SIZE - raw->count >= length)
487 			break;
488 		/* there might be another cpu waiting for the lock */
489 		spin_unlock(get_ccwdev_lock(raw->cdev));
490 		udelay(100);
491 		spin_lock(get_ccwdev_lock(raw->cdev));
492 	}
493 }
494 
495 /*
496  * String write routine for 3215 devices
497  */
498 static void
499 raw3215_write(struct raw3215_info *raw, const char *str, unsigned int length)
500 {
501 	unsigned long flags;
502 	int c, count;
503 
504 	while (length > 0) {
505 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
506 		count = (length > RAW3215_BUFFER_SIZE) ?
507 					     RAW3215_BUFFER_SIZE : length;
508 		length -= count;
509 
510 		raw3215_make_room(raw, count);
511 
512 		/* copy string to output buffer and convert it to EBCDIC */
513 		while (1) {
514 			c = min_t(int, count,
515 				  min(RAW3215_BUFFER_SIZE - raw->count,
516 				      RAW3215_BUFFER_SIZE - raw->head));
517 			if (c <= 0)
518 				break;
519 			memcpy(raw->buffer + raw->head, str, c);
520 			ASCEBC(raw->buffer + raw->head, c);
521 			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
522 			raw->count += c;
523 			raw->line_pos += c;
524 			str += c;
525 			count -= c;
526 		}
527 		if (!(raw->flags & RAW3215_WORKING)) {
528 			raw3215_mk_write_req(raw);
529 			/* start or queue request */
530 			raw3215_try_io(raw);
531 		}
532 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
533 	}
534 }
535 
536 /*
537  * Put character routine for 3215 devices
538  */
539 static void
540 raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
541 {
542 	unsigned long flags;
543 	unsigned int length, i;
544 
545 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
546 	if (ch == '\t') {
547 		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
548 		raw->line_pos += length;
549 		ch = ' ';
550 	} else if (ch == '\n') {
551 		length = 1;
552 		raw->line_pos = 0;
553 	} else {
554 		length = 1;
555 		raw->line_pos++;
556 	}
557 	raw3215_make_room(raw, length);
558 
559 	for (i = 0; i < length; i++) {
560 		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
561 		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
562 		raw->count++;
563 	}
564 	if (!(raw->flags & RAW3215_WORKING)) {
565 		raw3215_mk_write_req(raw);
566 		/* start or queue request */
567 		raw3215_try_io(raw);
568 	}
569 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
570 }
571 
572 /*
573  * Flush routine, it simply sets the flush flag and tries to start
574  * pending IO.
575  */
576 static void
577 raw3215_flush_buffer(struct raw3215_info *raw)
578 {
579 	unsigned long flags;
580 
581 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
582 	if (raw->count > 0) {
583 		raw->flags |= RAW3215_FLUSHING;
584 		raw3215_try_io(raw);
585 		raw->flags &= ~RAW3215_FLUSHING;
586 	}
587 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
588 }
589 
590 /*
591  * Fire up a 3215 device.
592  */
593 static int
594 raw3215_startup(struct raw3215_info *raw)
595 {
596 	unsigned long flags;
597 
598 	if (raw->flags & RAW3215_ACTIVE)
599 		return 0;
600 	raw->line_pos = 0;
601 	raw->flags |= RAW3215_ACTIVE;
602 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
603 	raw3215_try_io(raw);
604 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
605 
606 	return 0;
607 }
608 
609 /*
610  * Shutdown a 3215 device.
611  */
612 static void
613 raw3215_shutdown(struct raw3215_info *raw)
614 {
615 	DECLARE_WAITQUEUE(wait, current);
616 	unsigned long flags;
617 
618 	if (!(raw->flags & RAW3215_ACTIVE) || (raw->flags & RAW3215_FIXED))
619 		return;
620 	/* Wait for outstanding requests, then free irq */
621 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
622 	if ((raw->flags & RAW3215_WORKING) ||
623 	    raw->queued_write != NULL ||
624 	    raw->queued_read != NULL) {
625 		raw->flags |= RAW3215_CLOSING;
626 		add_wait_queue(&raw->empty_wait, &wait);
627 		set_current_state(TASK_INTERRUPTIBLE);
628 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
629 		schedule();
630 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
631 		remove_wait_queue(&raw->empty_wait, &wait);
632 		set_current_state(TASK_RUNNING);
633 		raw->flags &= ~(RAW3215_ACTIVE | RAW3215_CLOSING);
634 	}
635 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
636 }
637 
638 static int
639 raw3215_probe (struct ccw_device *cdev)
640 {
641 	struct raw3215_info *raw;
642 	int line;
643 
644 	/* Console is special. */
645 	if (raw3215[0] && (cdev->dev.driver_data == raw3215[0]))
646 		return 0;
647 	raw = kmalloc(sizeof(struct raw3215_info) +
648 		      RAW3215_INBUF_SIZE, GFP_KERNEL|GFP_DMA);
649 	if (raw == NULL)
650 		return -ENOMEM;
651 
652 	spin_lock(&raw3215_device_lock);
653 	for (line = 0; line < NR_3215; line++) {
654 		if (!raw3215[line]) {
655 			raw3215[line] = raw;
656 			break;
657 		}
658 	}
659 	spin_unlock(&raw3215_device_lock);
660 	if (line == NR_3215) {
661 		kfree(raw);
662 		return -ENODEV;
663 	}
664 
665 	raw->cdev = cdev;
666 	raw->inbuf = (char *) raw + sizeof(struct raw3215_info);
667 	memset(raw, 0, sizeof(struct raw3215_info));
668 	raw->buffer = kmalloc(RAW3215_BUFFER_SIZE,
669 				       GFP_KERNEL|GFP_DMA);
670 	if (raw->buffer == NULL) {
671 		spin_lock(&raw3215_device_lock);
672 		raw3215[line] = NULL;
673 		spin_unlock(&raw3215_device_lock);
674 		kfree(raw);
675 		return -ENOMEM;
676 	}
677 	tasklet_init(&raw->tasklet,
678 		     (void (*)(unsigned long)) raw3215_tasklet,
679 		     (unsigned long) raw);
680 	init_waitqueue_head(&raw->empty_wait);
681 
682 	cdev->dev.driver_data = raw;
683 	cdev->handler = raw3215_irq;
684 
685 	return 0;
686 }
687 
688 static void
689 raw3215_remove (struct ccw_device *cdev)
690 {
691 	struct raw3215_info *raw;
692 
693 	ccw_device_set_offline(cdev);
694 	raw = cdev->dev.driver_data;
695 	if (raw) {
696 		cdev->dev.driver_data = NULL;
697 		kfree(raw->buffer);
698 		kfree(raw);
699 	}
700 }
701 
702 static int
703 raw3215_set_online (struct ccw_device *cdev)
704 {
705 	struct raw3215_info *raw;
706 
707 	raw = cdev->dev.driver_data;
708 	if (!raw)
709 		return -ENODEV;
710 
711 	return raw3215_startup(raw);
712 }
713 
714 static int
715 raw3215_set_offline (struct ccw_device *cdev)
716 {
717 	struct raw3215_info *raw;
718 
719 	raw = cdev->dev.driver_data;
720 	if (!raw)
721 		return -ENODEV;
722 
723 	raw3215_shutdown(raw);
724 
725 	return 0;
726 }
727 
728 static struct ccw_device_id raw3215_id[] = {
729 	{ CCW_DEVICE(0x3215, 0) },
730 	{ /* end of list */ },
731 };
732 
733 static struct ccw_driver raw3215_ccw_driver = {
734 	.name		= "3215",
735 	.owner		= THIS_MODULE,
736 	.ids		= raw3215_id,
737 	.probe		= &raw3215_probe,
738 	.remove		= &raw3215_remove,
739 	.set_online	= &raw3215_set_online,
740 	.set_offline	= &raw3215_set_offline,
741 };
742 
743 #ifdef CONFIG_TN3215_CONSOLE
744 /*
745  * Write a string to the 3215 console
746  */
747 static void
748 con3215_write(struct console *co, const char *str, unsigned int count)
749 {
750 	struct raw3215_info *raw;
751 	int i;
752 
753 	if (count <= 0)
754 		return;
755 	raw = raw3215[0];	/* console 3215 is the first one */
756 	while (count > 0) {
757 		for (i = 0; i < count; i++)
758 			if (str[i] == '\t' || str[i] == '\n')
759 				break;
760 		raw3215_write(raw, str, i);
761 		count -= i;
762 		str += i;
763 		if (count > 0) {
764 			raw3215_putchar(raw, *str);
765 			count--;
766 			str++;
767 		}
768 	}
769 }
770 
771 static struct tty_driver *con3215_device(struct console *c, int *index)
772 {
773 	*index = c->index;
774 	return tty3215_driver;
775 }
776 
777 /*
778  * panic() calls console_unblank before the system enters a
779  * disabled, endless loop.
780  */
781 static void
782 con3215_unblank(void)
783 {
784 	struct raw3215_info *raw;
785 	unsigned long flags;
786 
787 	raw = raw3215[0];  /* console 3215 is the first one */
788 	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
789 	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
790 	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
791 }
792 
793 /*
794  *  The console structure for the 3215 console
795  */
796 static struct console con3215 = {
797 	.name	 = "ttyS",
798 	.write	 = con3215_write,
799 	.device	 = con3215_device,
800 	.unblank = con3215_unblank,
801 	.flags	 = CON_PRINTBUFFER,
802 };
803 
804 /*
805  * 3215 console initialization code called from console_init().
806  * NOTE: This is called before kmalloc is available.
807  */
808 static int __init
809 con3215_init(void)
810 {
811 	struct ccw_device *cdev;
812 	struct raw3215_info *raw;
813 	struct raw3215_req *req;
814 	int i;
815 
816 	/* Check if 3215 is to be the console */
817 	if (!CONSOLE_IS_3215)
818 		return -ENODEV;
819 
820 	/* Set the console mode for VM */
821 	if (MACHINE_IS_VM) {
822 		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
823 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
824 	}
825 
826 	/* allocate 3215 request structures */
827 	raw3215_freelist = NULL;
828 	spin_lock_init(&raw3215_freelist_lock);
829 	for (i = 0; i < NR_3215_REQ; i++) {
830 		req = (struct raw3215_req *) alloc_bootmem_low(sizeof(struct raw3215_req));
831 		req->next = raw3215_freelist;
832 		raw3215_freelist = req;
833 	}
834 
835 	cdev = ccw_device_probe_console();
836 	if (IS_ERR(cdev))
837 		return -ENODEV;
838 
839 	raw3215[0] = raw = (struct raw3215_info *)
840 		alloc_bootmem_low(sizeof(struct raw3215_info));
841 	memset(raw, 0, sizeof(struct raw3215_info));
842 	raw->buffer = (char *) alloc_bootmem_low(RAW3215_BUFFER_SIZE);
843 	raw->inbuf = (char *) alloc_bootmem_low(RAW3215_INBUF_SIZE);
844 	raw->cdev = cdev;
845 	cdev->dev.driver_data = raw;
846 	cdev->handler = raw3215_irq;
847 
848 	raw->flags |= RAW3215_FIXED;
849 	tasklet_init(&raw->tasklet,
850 		     (void (*)(unsigned long)) raw3215_tasklet,
851 		     (unsigned long) raw);
852 	init_waitqueue_head(&raw->empty_wait);
853 
854 	/* Request the console irq */
855 	if (raw3215_startup(raw) != 0) {
856 		free_bootmem((unsigned long) raw->inbuf, RAW3215_INBUF_SIZE);
857 		free_bootmem((unsigned long) raw->buffer, RAW3215_BUFFER_SIZE);
858 		free_bootmem((unsigned long) raw, sizeof(struct raw3215_info));
859 		raw3215[0] = NULL;
860 		return -ENODEV;
861 	}
862 	register_console(&con3215);
863 	return 0;
864 }
865 console_initcall(con3215_init);
866 #endif
867 
868 /*
869  * tty3215_open
870  *
871  * This routine is called whenever a 3215 tty is opened.
872  */
873 static int
874 tty3215_open(struct tty_struct *tty, struct file * filp)
875 {
876 	struct raw3215_info *raw;
877 	int retval, line;
878 
879 	line = tty->index;
880 	if ((line < 0) || (line >= NR_3215))
881 		return -ENODEV;
882 
883 	raw = raw3215[line];
884 	if (raw == NULL)
885 		return -ENODEV;
886 
887 	tty->driver_data = raw;
888 	raw->tty = tty;
889 
890 	tty->low_latency = 0;  /* don't use bottom half for pushing chars */
891 	/*
892 	 * Start up 3215 device
893 	 */
894 	retval = raw3215_startup(raw);
895 	if (retval)
896 		return retval;
897 
898 	return 0;
899 }
900 
901 /*
902  * tty3215_close()
903  *
904  * This routine is called when the 3215 tty is closed. We wait
905  * for the remaining request to be completed. Then we clean up.
906  */
907 static void
908 tty3215_close(struct tty_struct *tty, struct file * filp)
909 {
910 	struct raw3215_info *raw;
911 
912 	raw = (struct raw3215_info *) tty->driver_data;
913 	if (raw == NULL || tty->count > 1)
914 		return;
915 	tty->closing = 1;
916 	/* Shutdown the terminal */
917 	raw3215_shutdown(raw);
918 	tty->closing = 0;
919 	raw->tty = NULL;
920 }
921 
922 /*
923  * Returns the amount of free space in the output buffer.
924  */
925 static int
926 tty3215_write_room(struct tty_struct *tty)
927 {
928 	struct raw3215_info *raw;
929 
930 	raw = (struct raw3215_info *) tty->driver_data;
931 
932 	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
933 	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
934 		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
935 	else
936 		return 0;
937 }
938 
939 /*
940  * String write routine for 3215 ttys
941  */
942 static int
943 tty3215_write(struct tty_struct * tty,
944 	      const unsigned char *buf, int count)
945 {
946 	struct raw3215_info *raw;
947 
948 	if (!tty)
949 		return 0;
950 	raw = (struct raw3215_info *) tty->driver_data;
951 	raw3215_write(raw, buf, count);
952 	return count;
953 }
954 
955 /*
956  * Put character routine for 3215 ttys
957  */
958 static int
959 tty3215_put_char(struct tty_struct *tty, unsigned char ch)
960 {
961 	struct raw3215_info *raw;
962 
963 	if (!tty)
964 		return 0;
965 	raw = (struct raw3215_info *) tty->driver_data;
966 	raw3215_putchar(raw, ch);
967 	return 1;
968 }
969 
970 static void
971 tty3215_flush_chars(struct tty_struct *tty)
972 {
973 }
974 
975 /*
976  * Returns the number of characters in the output buffer
977  */
978 static int
979 tty3215_chars_in_buffer(struct tty_struct *tty)
980 {
981 	struct raw3215_info *raw;
982 
983 	raw = (struct raw3215_info *) tty->driver_data;
984 	return raw->count;
985 }
986 
987 static void
988 tty3215_flush_buffer(struct tty_struct *tty)
989 {
990 	struct raw3215_info *raw;
991 
992 	raw = (struct raw3215_info *) tty->driver_data;
993 	raw3215_flush_buffer(raw);
994 	tty_wakeup(tty);
995 }
996 
997 /*
998  * Currently we don't have any io controls for 3215 ttys
999  */
1000 static int
1001 tty3215_ioctl(struct tty_struct *tty, struct file * file,
1002 	      unsigned int cmd, unsigned long arg)
1003 {
1004 	if (tty->flags & (1 << TTY_IO_ERROR))
1005 		return -EIO;
1006 
1007 	switch (cmd) {
1008 	default:
1009 		return -ENOIOCTLCMD;
1010 	}
1011 	return 0;
1012 }
1013 
1014 /*
1015  * Disable reading from a 3215 tty
1016  */
1017 static void
1018 tty3215_throttle(struct tty_struct * tty)
1019 {
1020 	struct raw3215_info *raw;
1021 
1022 	raw = (struct raw3215_info *) tty->driver_data;
1023 	raw->flags |= RAW3215_THROTTLED;
1024 }
1025 
1026 /*
1027  * Enable reading from a 3215 tty
1028  */
1029 static void
1030 tty3215_unthrottle(struct tty_struct * tty)
1031 {
1032 	struct raw3215_info *raw;
1033 	unsigned long flags;
1034 
1035 	raw = (struct raw3215_info *) tty->driver_data;
1036 	if (raw->flags & RAW3215_THROTTLED) {
1037 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1038 		raw->flags &= ~RAW3215_THROTTLED;
1039 		raw3215_try_io(raw);
1040 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1041 	}
1042 }
1043 
1044 /*
1045  * Disable writing to a 3215 tty
1046  */
1047 static void
1048 tty3215_stop(struct tty_struct *tty)
1049 {
1050 	struct raw3215_info *raw;
1051 
1052 	raw = (struct raw3215_info *) tty->driver_data;
1053 	raw->flags |= RAW3215_STOPPED;
1054 }
1055 
1056 /*
1057  * Enable writing to a 3215 tty
1058  */
1059 static void
1060 tty3215_start(struct tty_struct *tty)
1061 {
1062 	struct raw3215_info *raw;
1063 	unsigned long flags;
1064 
1065 	raw = (struct raw3215_info *) tty->driver_data;
1066 	if (raw->flags & RAW3215_STOPPED) {
1067 		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1068 		raw->flags &= ~RAW3215_STOPPED;
1069 		raw3215_try_io(raw);
1070 		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1071 	}
1072 }
1073 
1074 static const struct tty_operations tty3215_ops = {
1075 	.open = tty3215_open,
1076 	.close = tty3215_close,
1077 	.write = tty3215_write,
1078 	.put_char = tty3215_put_char,
1079 	.flush_chars = tty3215_flush_chars,
1080 	.write_room = tty3215_write_room,
1081 	.chars_in_buffer = tty3215_chars_in_buffer,
1082 	.flush_buffer = tty3215_flush_buffer,
1083 	.ioctl = tty3215_ioctl,
1084 	.throttle = tty3215_throttle,
1085 	.unthrottle = tty3215_unthrottle,
1086 	.stop = tty3215_stop,
1087 	.start = tty3215_start,
1088 };
1089 
1090 /*
1091  * 3215 tty registration code called from tty_init().
1092  * Most kernel services (incl. kmalloc) are available at this poimt.
1093  */
1094 static int __init
1095 tty3215_init(void)
1096 {
1097 	struct tty_driver *driver;
1098 	int ret;
1099 
1100 	if (!CONSOLE_IS_3215)
1101 		return 0;
1102 
1103 	driver = alloc_tty_driver(NR_3215);
1104 	if (!driver)
1105 		return -ENOMEM;
1106 
1107 	ret = ccw_driver_register(&raw3215_ccw_driver);
1108 	if (ret) {
1109 		put_tty_driver(driver);
1110 		return ret;
1111 	}
1112 	/*
1113 	 * Initialize the tty_driver structure
1114 	 * Entries in tty3215_driver that are NOT initialized:
1115 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1116 	 */
1117 
1118 	driver->owner = THIS_MODULE;
1119 	driver->driver_name = "tty3215";
1120 	driver->name = "ttyS";
1121 	driver->major = TTY_MAJOR;
1122 	driver->minor_start = 64;
1123 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1124 	driver->subtype = SYSTEM_TYPE_TTY;
1125 	driver->init_termios = tty_std_termios;
1126 	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1127 	driver->init_termios.c_oflag = ONLCR | XTABS;
1128 	driver->init_termios.c_lflag = ISIG;
1129 	driver->flags = TTY_DRIVER_REAL_RAW;
1130 	tty_set_operations(driver, &tty3215_ops);
1131 	ret = tty_register_driver(driver);
1132 	if (ret) {
1133 		put_tty_driver(driver);
1134 		return ret;
1135 	}
1136 	tty3215_driver = driver;
1137 	return 0;
1138 }
1139 
1140 static void __exit
1141 tty3215_exit(void)
1142 {
1143 	tty_unregister_driver(tty3215_driver);
1144 	put_tty_driver(tty3215_driver);
1145 	ccw_driver_unregister(&raw3215_ccw_driver);
1146 }
1147 
1148 module_init(tty3215_init);
1149 module_exit(tty3215_exit);
1150