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 */
59enum raw3215_type {
60	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
61};
62
63/*
64 * Request structure for a 3215 device
65 */
66struct 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
76struct 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	struct tasklet_struct tlet;   /* tasklet to invoke tty_wakeup */
89	wait_queue_head_t empty_wait; /* wait queue for flushing */
90	struct timer_list timer;      /* timer for delayed output */
91	int line_pos;		      /* position on the line (for tabs) */
92	char ubuffer[80];	      /* copy_from_user buffer */
93};
94
95/* array of 3215 devices structures */
96static struct raw3215_info *raw3215[NR_3215];
97/* spinlock to protect the raw3215 array */
98static DEFINE_SPINLOCK(raw3215_device_lock);
99/* list of free request structures */
100static struct raw3215_req *raw3215_freelist;
101/* spinlock to protect free list */
102static spinlock_t raw3215_freelist_lock;
103
104static struct tty_driver *tty3215_driver;
105
106/*
107 * Get a request structure from the free list
108 */
109static inline struct raw3215_req *raw3215_alloc_req(void)
110{
111	struct raw3215_req *req;
112	unsigned long flags;
113
114	spin_lock_irqsave(&raw3215_freelist_lock, flags);
115	req = raw3215_freelist;
116	raw3215_freelist = req->next;
117	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
118	return req;
119}
120
121/*
122 * Put a request structure back to the free list
123 */
124static inline void raw3215_free_req(struct raw3215_req *req)
125{
126	unsigned long flags;
127
128	if (req->type == RAW3215_FREE)
129		return;		/* don't free a free request */
130	req->type = RAW3215_FREE;
131	spin_lock_irqsave(&raw3215_freelist_lock, flags);
132	req->next = raw3215_freelist;
133	raw3215_freelist = req;
134	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
135}
136
137/*
138 * Set up a read request that reads up to 160 byte from the 3215 device.
139 * If there is a queued read request it is used, but that shouldn't happen
140 * because a 3215 terminal won't accept a new read before the old one is
141 * completed.
142 */
143static void raw3215_mk_read_req(struct raw3215_info *raw)
144{
145	struct raw3215_req *req;
146	struct ccw1 *ccw;
147
148	/* there can only be ONE read request at a time */
149	req = raw->queued_read;
150	if (req == NULL) {
151		/* no queued read request, use new req structure */
152		req = raw3215_alloc_req();
153		req->type = RAW3215_READ;
154		req->info = raw;
155		raw->queued_read = req;
156	}
157
158	ccw = req->ccws;
159	ccw->cmd_code = 0x0A; /* read inquiry */
160	ccw->flags = 0x20;    /* ignore incorrect length */
161	ccw->count = 160;
162	ccw->cda = (__u32) __pa(raw->inbuf);
163}
164
165/*
166 * Set up a write request with the information from the main structure.
167 * A ccw chain is created that writes as much as possible from the output
168 * buffer to the 3215 device. If a queued write exists it is replaced by
169 * the new, probably lengthened request.
170 */
171static void raw3215_mk_write_req(struct raw3215_info *raw)
172{
173	struct raw3215_req *req;
174	struct ccw1 *ccw;
175	int len, count, ix, lines;
176
177	if (raw->count <= raw->written)
178		return;
179	/* check if there is a queued write request */
180	req = raw->queued_write;
181	if (req == NULL) {
182		/* no queued write request, use new req structure */
183		req = raw3215_alloc_req();
184		req->type = RAW3215_WRITE;
185		req->info = raw;
186		raw->queued_write = req;
187	} else {
188		raw->written -= req->len;
189	}
190
191	ccw = req->ccws;
192	req->start = (raw->head - raw->count + raw->written) &
193		     (RAW3215_BUFFER_SIZE - 1);
194	/*
195	 * now we have to count newlines. We can at max accept
196	 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
197	 * a restriction in VM
198	 */
199	lines = 0;
200	ix = req->start;
201	while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
202		if (raw->buffer[ix] == 0x15)
203			lines++;
204		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
205	}
206	len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
207	if (len > RAW3215_MAX_BYTES)
208		len = RAW3215_MAX_BYTES;
209	req->len = len;
210	raw->written += len;
211
212	/* set the indication if we should try to enlarge this request */
213	req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
214
215	ix = req->start;
216	while (len > 0) {
217		if (ccw > req->ccws)
218			ccw[-1].flags |= 0x40; /* use command chaining */
219		ccw->cmd_code = 0x01; /* write, auto carrier return */
220		ccw->flags = 0x20;    /* ignore incorrect length ind.  */
221		ccw->cda =
222			(__u32) __pa(raw->buffer + ix);
223		count = len;
224		if (ix + count > RAW3215_BUFFER_SIZE)
225			count = RAW3215_BUFFER_SIZE - ix;
226		ccw->count = count;
227		len -= count;
228		ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
229		ccw++;
230	}
231	/*
232	 * Add a NOP to the channel program. 3215 devices are purely
233	 * emulated and its much better to avoid the channel end
234	 * interrupt in this case.
235	 */
236	if (ccw > req->ccws)
237		ccw[-1].flags |= 0x40; /* use command chaining */
238	ccw->cmd_code = 0x03; /* NOP */
239	ccw->flags = 0;
240	ccw->cda = 0;
241	ccw->count = 1;
242}
243
244/*
245 * Start a read or a write request
246 */
247static void raw3215_start_io(struct raw3215_info *raw)
248{
249	struct raw3215_req *req;
250	int res;
251
252	req = raw->queued_read;
253	if (req != NULL &&
254	    !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
255		/* dequeue request */
256		raw->queued_read = NULL;
257		res = ccw_device_start(raw->cdev, req->ccws,
258				       (unsigned long) req, 0, 0);
259		if (res != 0) {
260			/* do_IO failed, put request back to queue */
261			raw->queued_read = req;
262		} else {
263			raw->flags |= RAW3215_WORKING;
264		}
265	}
266	req = raw->queued_write;
267	if (req != NULL &&
268	    !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
269		/* dequeue request */
270		raw->queued_write = NULL;
271		res = ccw_device_start(raw->cdev, req->ccws,
272				       (unsigned long) req, 0, 0);
273		if (res != 0) {
274			/* do_IO failed, put request back to queue */
275			raw->queued_write = req;
276		} else {
277			raw->flags |= RAW3215_WORKING;
278		}
279	}
280}
281
282/*
283 * Function to start a delayed output after RAW3215_TIMEOUT seconds
284 */
285static void raw3215_timeout(struct timer_list *t)
286{
287	struct raw3215_info *raw = from_timer(raw, t, timer);
288	unsigned long flags;
289
290	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
291	raw->flags &= ~RAW3215_TIMER_RUNS;
292	if (!tty_port_suspended(&raw->port)) {
293		raw3215_mk_write_req(raw);
294		raw3215_start_io(raw);
295		if ((raw->queued_read || raw->queued_write) &&
296		    !(raw->flags & RAW3215_WORKING) &&
297		    !(raw->flags & RAW3215_TIMER_RUNS)) {
298			raw->timer.expires = RAW3215_TIMEOUT + jiffies;
299			add_timer(&raw->timer);
300			raw->flags |= RAW3215_TIMER_RUNS;
301		}
302	}
303	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
304}
305
306/*
307 * Function to conditionally start an IO. A read is started immediately,
308 * a write is only started immediately if the flush flag is on or the
309 * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
310 * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
311 */
312static inline void raw3215_try_io(struct raw3215_info *raw)
313{
314	if (!tty_port_initialized(&raw->port) || tty_port_suspended(&raw->port))
315		return;
316	if (raw->queued_read != NULL)
317		raw3215_start_io(raw);
318	else if (raw->queued_write != NULL) {
319		if ((raw->queued_write->delayable == 0) ||
320		    (raw->flags & RAW3215_FLUSHING)) {
321			/* execute write requests bigger than minimum size */
322			raw3215_start_io(raw);
323		}
324	}
325	if ((raw->queued_read || raw->queued_write) &&
326	    !(raw->flags & RAW3215_WORKING) &&
327	    !(raw->flags & RAW3215_TIMER_RUNS)) {
328		raw->timer.expires = RAW3215_TIMEOUT + jiffies;
329		add_timer(&raw->timer);
330		raw->flags |= RAW3215_TIMER_RUNS;
331	}
332}
333
334/*
335 * Call tty_wakeup from tasklet context
336 */
337static void raw3215_wakeup(unsigned long data)
338{
339	struct raw3215_info *raw = (struct raw3215_info *) data;
340	struct tty_struct *tty;
341
342	tty = tty_port_tty_get(&raw->port);
343	if (tty) {
344		tty_wakeup(tty);
345		tty_kref_put(tty);
346	}
347}
348
349/*
350 * Try to start the next IO and wake up processes waiting on the tty.
351 */
352static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
353{
354	raw3215_mk_write_req(raw);
355	raw3215_try_io(raw);
356	if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
357		tasklet_schedule(&raw->tlet);
358}
359
360/*
361 * Interrupt routine, called from common io layer
362 */
363static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
364			struct irb *irb)
365{
366	struct raw3215_info *raw;
367	struct raw3215_req *req;
368	struct tty_struct *tty;
369	int cstat, dstat;
370	int count;
371
372	raw = dev_get_drvdata(&cdev->dev);
373	req = (struct raw3215_req *) intparm;
374	tty = tty_port_tty_get(&raw->port);
375	cstat = irb->scsw.cmd.cstat;
376	dstat = irb->scsw.cmd.dstat;
377	if (cstat != 0)
378		raw3215_next_io(raw, tty);
379	if (dstat & 0x01) { /* we got a unit exception */
380		dstat &= ~0x01;	 /* we can ignore it */
381	}
382	switch (dstat) {
383	case 0x80:
384		if (cstat != 0)
385			break;
386		/* Attention interrupt, someone hit the enter key */
387		raw3215_mk_read_req(raw);
388		raw3215_next_io(raw, tty);
389		break;
390	case 0x08:
391	case 0x0C:
392		/* Channel end interrupt. */
393		if ((raw = req->info) == NULL)
394			goto put_tty;	     /* That shouldn't happen ... */
395		if (req->type == RAW3215_READ) {
396			/* store residual count, then wait for device end */
397			req->residual = irb->scsw.cmd.count;
398		}
399		if (dstat == 0x08)
400			break;
401		fallthrough;
402	case 0x04:
403		/* Device end interrupt. */
404		if ((raw = req->info) == NULL)
405			goto put_tty;	     /* That shouldn't happen ... */
406		if (req->type == RAW3215_READ && tty != NULL) {
407			unsigned int cchar;
408
409			count = 160 - req->residual;
410			EBCASC(raw->inbuf, count);
411			cchar = ctrlchar_handle(raw->inbuf, count, tty);
412			switch (cchar & CTRLCHAR_MASK) {
413			case CTRLCHAR_SYSRQ:
414				break;
415
416			case CTRLCHAR_CTRL:
417				tty_insert_flip_char(&raw->port, cchar,
418						TTY_NORMAL);
419				tty_flip_buffer_push(&raw->port);
420				break;
421
422			case CTRLCHAR_NONE:
423				if (count < 2 ||
424				    (strncmp(raw->inbuf+count-2, "\252n", 2) &&
425				     strncmp(raw->inbuf+count-2, "^n", 2)) ) {
426					/* add the auto \n */
427					raw->inbuf[count] = '\n';
428					count++;
429				} else
430					count -= 2;
431				tty_insert_flip_string(&raw->port, raw->inbuf,
432						count);
433				tty_flip_buffer_push(&raw->port);
434				break;
435			}
436		} else if (req->type == RAW3215_WRITE) {
437			raw->count -= req->len;
438			raw->written -= req->len;
439		}
440		raw->flags &= ~RAW3215_WORKING;
441		raw3215_free_req(req);
442		/* check for empty wait */
443		if (waitqueue_active(&raw->empty_wait) &&
444		    raw->queued_write == NULL &&
445		    raw->queued_read == NULL) {
446			wake_up_interruptible(&raw->empty_wait);
447		}
448		raw3215_next_io(raw, tty);
449		break;
450	default:
451		/* Strange interrupt, I'll do my best to clean up */
452		if (req != NULL && req->type != RAW3215_FREE) {
453			if (req->type == RAW3215_WRITE) {
454				raw->count -= req->len;
455				raw->written -= req->len;
456			}
457			raw->flags &= ~RAW3215_WORKING;
458			raw3215_free_req(req);
459		}
460		raw3215_next_io(raw, tty);
461	}
462put_tty:
463	tty_kref_put(tty);
464}
465
466/*
467 * Drop the oldest line from the output buffer.
468 */
469static void raw3215_drop_line(struct raw3215_info *raw)
470{
471	int ix;
472	char ch;
473
474	BUG_ON(raw->written != 0);
475	ix = (raw->head - raw->count) & (RAW3215_BUFFER_SIZE - 1);
476	while (raw->count > 0) {
477		ch = raw->buffer[ix];
478		ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
479		raw->count--;
480		if (ch == 0x15)
481			break;
482	}
483	raw->head = ix;
484}
485
486/*
487 * Wait until length bytes are available int the output buffer.
488 * Has to be called with the s390irq lock held. Can be called
489 * disabled.
490 */
491static void raw3215_make_room(struct raw3215_info *raw, unsigned int length)
492{
493	while (RAW3215_BUFFER_SIZE - raw->count < length) {
494		/* While console is frozen for suspend we have no other
495		 * choice but to drop message from the buffer to make
496		 * room for even more messages. */
497		if (tty_port_suspended(&raw->port)) {
498			raw3215_drop_line(raw);
499			continue;
500		}
501		/* there might be a request pending */
502		raw->flags |= RAW3215_FLUSHING;
503		raw3215_mk_write_req(raw);
504		raw3215_try_io(raw);
505		raw->flags &= ~RAW3215_FLUSHING;
506#ifdef CONFIG_TN3215_CONSOLE
507		ccw_device_wait_idle(raw->cdev);
508#endif
509		/* Enough room freed up ? */
510		if (RAW3215_BUFFER_SIZE - raw->count >= length)
511			break;
512		/* there might be another cpu waiting for the lock */
513		spin_unlock(get_ccwdev_lock(raw->cdev));
514		udelay(100);
515		spin_lock(get_ccwdev_lock(raw->cdev));
516	}
517}
518
519/*
520 * String write routine for 3215 devices
521 */
522static void raw3215_write(struct raw3215_info *raw, const char *str,
523			  unsigned int length)
524{
525	unsigned long flags;
526	int c, count;
527
528	while (length > 0) {
529		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
530		count = (length > RAW3215_BUFFER_SIZE) ?
531					     RAW3215_BUFFER_SIZE : length;
532		length -= count;
533
534		raw3215_make_room(raw, count);
535
536		/* copy string to output buffer and convert it to EBCDIC */
537		while (1) {
538			c = min_t(int, count,
539				  min(RAW3215_BUFFER_SIZE - raw->count,
540				      RAW3215_BUFFER_SIZE - raw->head));
541			if (c <= 0)
542				break;
543			memcpy(raw->buffer + raw->head, str, c);
544			ASCEBC(raw->buffer + raw->head, c);
545			raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
546			raw->count += c;
547			raw->line_pos += c;
548			str += c;
549			count -= c;
550		}
551		if (!(raw->flags & RAW3215_WORKING)) {
552			raw3215_mk_write_req(raw);
553			/* start or queue request */
554			raw3215_try_io(raw);
555		}
556		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
557	}
558}
559
560/*
561 * Put character routine for 3215 devices
562 */
563static void raw3215_putchar(struct raw3215_info *raw, unsigned char ch)
564{
565	unsigned long flags;
566	unsigned int length, i;
567
568	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
569	if (ch == '\t') {
570		length = TAB_STOP_SIZE - (raw->line_pos%TAB_STOP_SIZE);
571		raw->line_pos += length;
572		ch = ' ';
573	} else if (ch == '\n') {
574		length = 1;
575		raw->line_pos = 0;
576	} else {
577		length = 1;
578		raw->line_pos++;
579	}
580	raw3215_make_room(raw, length);
581
582	for (i = 0; i < length; i++) {
583		raw->buffer[raw->head] = (char) _ascebc[(int) ch];
584		raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
585		raw->count++;
586	}
587	if (!(raw->flags & RAW3215_WORKING)) {
588		raw3215_mk_write_req(raw);
589		/* start or queue request */
590		raw3215_try_io(raw);
591	}
592	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
593}
594
595/*
596 * Flush routine, it simply sets the flush flag and tries to start
597 * pending IO.
598 */
599static void raw3215_flush_buffer(struct raw3215_info *raw)
600{
601	unsigned long flags;
602
603	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
604	if (raw->count > 0) {
605		raw->flags |= RAW3215_FLUSHING;
606		raw3215_try_io(raw);
607		raw->flags &= ~RAW3215_FLUSHING;
608	}
609	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
610}
611
612/*
613 * Fire up a 3215 device.
614 */
615static int raw3215_startup(struct raw3215_info *raw)
616{
617	unsigned long flags;
618
619	if (tty_port_initialized(&raw->port))
620		return 0;
621	raw->line_pos = 0;
622	tty_port_set_initialized(&raw->port, 1);
623	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
624	raw3215_try_io(raw);
625	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
626
627	return 0;
628}
629
630/*
631 * Shutdown a 3215 device.
632 */
633static void raw3215_shutdown(struct raw3215_info *raw)
634{
635	DECLARE_WAITQUEUE(wait, current);
636	unsigned long flags;
637
638	if (!tty_port_initialized(&raw->port) || (raw->flags & RAW3215_FIXED))
639		return;
640	/* Wait for outstanding requests, then free irq */
641	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
642	if ((raw->flags & RAW3215_WORKING) ||
643	    raw->queued_write != NULL ||
644	    raw->queued_read != NULL) {
645		add_wait_queue(&raw->empty_wait, &wait);
646		set_current_state(TASK_INTERRUPTIBLE);
647		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
648		schedule();
649		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
650		remove_wait_queue(&raw->empty_wait, &wait);
651		set_current_state(TASK_RUNNING);
652		tty_port_set_initialized(&raw->port, 1);
653	}
654	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
655}
656
657static struct raw3215_info *raw3215_alloc_info(void)
658{
659	struct raw3215_info *info;
660
661	info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
662	if (!info)
663		return NULL;
664
665	info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
666	info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
667	if (!info->buffer || !info->inbuf) {
668		kfree(info->inbuf);
669		kfree(info->buffer);
670		kfree(info);
671		return NULL;
672	}
673
674	timer_setup(&info->timer, raw3215_timeout, 0);
675	init_waitqueue_head(&info->empty_wait);
676	tasklet_init(&info->tlet, raw3215_wakeup, (unsigned long)info);
677	tty_port_init(&info->port);
678
679	return info;
680}
681
682static void raw3215_free_info(struct raw3215_info *raw)
683{
684	kfree(raw->inbuf);
685	kfree(raw->buffer);
686	tty_port_destroy(&raw->port);
687	kfree(raw);
688}
689
690static int raw3215_probe (struct ccw_device *cdev)
691{
692	struct raw3215_info *raw;
693	int line;
694
695	/* Console is special. */
696	if (raw3215[0] && (raw3215[0] == dev_get_drvdata(&cdev->dev)))
697		return 0;
698
699	raw = raw3215_alloc_info();
700	if (raw == NULL)
701		return -ENOMEM;
702
703	raw->cdev = cdev;
704	dev_set_drvdata(&cdev->dev, raw);
705	cdev->handler = raw3215_irq;
706
707	spin_lock(&raw3215_device_lock);
708	for (line = 0; line < NR_3215; line++) {
709		if (!raw3215[line]) {
710			raw3215[line] = raw;
711			break;
712		}
713	}
714	spin_unlock(&raw3215_device_lock);
715	if (line == NR_3215) {
716		raw3215_free_info(raw);
717		return -ENODEV;
718	}
719
720	return 0;
721}
722
723static void raw3215_remove (struct ccw_device *cdev)
724{
725	struct raw3215_info *raw;
726	unsigned int line;
727
728	ccw_device_set_offline(cdev);
729	raw = dev_get_drvdata(&cdev->dev);
730	if (raw) {
731		spin_lock(&raw3215_device_lock);
732		for (line = 0; line < NR_3215; line++)
733			if (raw3215[line] == raw)
734				break;
735		raw3215[line] = NULL;
736		spin_unlock(&raw3215_device_lock);
737		dev_set_drvdata(&cdev->dev, NULL);
738		raw3215_free_info(raw);
739	}
740}
741
742static int raw3215_set_online (struct ccw_device *cdev)
743{
744	struct raw3215_info *raw;
745
746	raw = dev_get_drvdata(&cdev->dev);
747	if (!raw)
748		return -ENODEV;
749
750	return raw3215_startup(raw);
751}
752
753static int raw3215_set_offline (struct ccw_device *cdev)
754{
755	struct raw3215_info *raw;
756
757	raw = dev_get_drvdata(&cdev->dev);
758	if (!raw)
759		return -ENODEV;
760
761	raw3215_shutdown(raw);
762
763	return 0;
764}
765
766static int raw3215_pm_stop(struct ccw_device *cdev)
767{
768	struct raw3215_info *raw;
769	unsigned long flags;
770
771	/* Empty the output buffer, then prevent new I/O. */
772	raw = dev_get_drvdata(&cdev->dev);
773	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
774	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
775	tty_port_set_suspended(&raw->port, 1);
776	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
777	return 0;
778}
779
780static int raw3215_pm_start(struct ccw_device *cdev)
781{
782	struct raw3215_info *raw;
783	unsigned long flags;
784
785	/* Allow I/O again and flush output buffer. */
786	raw = dev_get_drvdata(&cdev->dev);
787	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
788	tty_port_set_suspended(&raw->port, 0);
789	raw->flags |= RAW3215_FLUSHING;
790	raw3215_try_io(raw);
791	raw->flags &= ~RAW3215_FLUSHING;
792	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
793	return 0;
794}
795
796static struct ccw_device_id raw3215_id[] = {
797	{ CCW_DEVICE(0x3215, 0) },
798	{ /* end of list */ },
799};
800
801static struct ccw_driver raw3215_ccw_driver = {
802	.driver = {
803		.name	= "3215",
804		.owner	= THIS_MODULE,
805	},
806	.ids		= raw3215_id,
807	.probe		= &raw3215_probe,
808	.remove		= &raw3215_remove,
809	.set_online	= &raw3215_set_online,
810	.set_offline	= &raw3215_set_offline,
811	.freeze		= &raw3215_pm_stop,
812	.thaw		= &raw3215_pm_start,
813	.restore	= &raw3215_pm_start,
814	.int_class	= IRQIO_C15,
815};
816
817#ifdef CONFIG_TN3215_CONSOLE
818/*
819 * Write a string to the 3215 console
820 */
821static void con3215_write(struct console *co, const char *str,
822			  unsigned int count)
823{
824	struct raw3215_info *raw;
825	int i;
826
827	if (count <= 0)
828		return;
829	raw = raw3215[0];	/* console 3215 is the first one */
830	while (count > 0) {
831		for (i = 0; i < count; i++)
832			if (str[i] == '\t' || str[i] == '\n')
833				break;
834		raw3215_write(raw, str, i);
835		count -= i;
836		str += i;
837		if (count > 0) {
838			raw3215_putchar(raw, *str);
839			count--;
840			str++;
841		}
842	}
843}
844
845static struct tty_driver *con3215_device(struct console *c, int *index)
846{
847	*index = c->index;
848	return tty3215_driver;
849}
850
851/*
852 * panic() calls con3215_flush through a panic_notifier
853 * before the system enters a disabled, endless loop.
854 */
855static void con3215_flush(void)
856{
857	struct raw3215_info *raw;
858	unsigned long flags;
859
860	raw = raw3215[0];  /* console 3215 is the first one */
861	if (tty_port_suspended(&raw->port))
862		/* The console is still frozen for suspend. */
863		if (ccw_device_force_console(raw->cdev))
864			/* Forcing didn't work, no panic message .. */
865			return;
866	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
867	raw3215_make_room(raw, RAW3215_BUFFER_SIZE);
868	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
869}
870
871static int con3215_notify(struct notifier_block *self,
872			  unsigned long event, void *data)
873{
874	con3215_flush();
875	return NOTIFY_OK;
876}
877
878static struct notifier_block on_panic_nb = {
879	.notifier_call = con3215_notify,
880	.priority = 0,
881};
882
883static struct notifier_block on_reboot_nb = {
884	.notifier_call = con3215_notify,
885	.priority = 0,
886};
887
888/*
889 *  The console structure for the 3215 console
890 */
891static struct console con3215 = {
892	.name	 = "ttyS",
893	.write	 = con3215_write,
894	.device	 = con3215_device,
895	.flags	 = CON_PRINTBUFFER,
896};
897
898/*
899 * 3215 console initialization code called from console_init().
900 */
901static int __init con3215_init(void)
902{
903	struct ccw_device *cdev;
904	struct raw3215_info *raw;
905	struct raw3215_req *req;
906	int i;
907
908	/* Check if 3215 is to be the console */
909	if (!CONSOLE_IS_3215)
910		return -ENODEV;
911
912	/* Set the console mode for VM */
913	if (MACHINE_IS_VM) {
914		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
915		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
916	}
917
918	/* allocate 3215 request structures */
919	raw3215_freelist = NULL;
920	spin_lock_init(&raw3215_freelist_lock);
921	for (i = 0; i < NR_3215_REQ; i++) {
922		req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
923		if (!req)
924			return -ENOMEM;
925		req->next = raw3215_freelist;
926		raw3215_freelist = req;
927	}
928
929	cdev = ccw_device_create_console(&raw3215_ccw_driver);
930	if (IS_ERR(cdev))
931		return -ENODEV;
932
933	raw3215[0] = raw = raw3215_alloc_info();
934	raw->cdev = cdev;
935	dev_set_drvdata(&cdev->dev, raw);
936	cdev->handler = raw3215_irq;
937
938	raw->flags |= RAW3215_FIXED;
939	if (ccw_device_enable_console(cdev)) {
940		ccw_device_destroy_console(cdev);
941		raw3215_free_info(raw);
942		raw3215[0] = NULL;
943		return -ENODEV;
944	}
945
946	/* Request the console irq */
947	if (raw3215_startup(raw) != 0) {
948		raw3215_free_info(raw);
949		raw3215[0] = NULL;
950		return -ENODEV;
951	}
952	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
953	register_reboot_notifier(&on_reboot_nb);
954	register_console(&con3215);
955	return 0;
956}
957console_initcall(con3215_init);
958#endif
959
960static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
961{
962	struct raw3215_info *raw;
963
964	raw = raw3215[tty->index];
965	if (raw == NULL)
966		return -ENODEV;
967
968	tty->driver_data = raw;
969
970	return tty_port_install(&raw->port, driver, tty);
971}
972
973/*
974 * tty3215_open
975 *
976 * This routine is called whenever a 3215 tty is opened.
977 */
978static int tty3215_open(struct tty_struct *tty, struct file * filp)
979{
980	struct raw3215_info *raw = tty->driver_data;
981
982	tty_port_tty_set(&raw->port, tty);
983
984	raw->port.low_latency = 0; /* don't use bottom half for pushing chars */
985	/*
986	 * Start up 3215 device
987	 */
988	return raw3215_startup(raw);
989}
990
991/*
992 * tty3215_close()
993 *
994 * This routine is called when the 3215 tty is closed. We wait
995 * for the remaining request to be completed. Then we clean up.
996 */
997static void tty3215_close(struct tty_struct *tty, struct file * filp)
998{
999	struct raw3215_info *raw;
1000
1001	raw = (struct raw3215_info *) tty->driver_data;
1002	if (raw == NULL || tty->count > 1)
1003		return;
1004	tty->closing = 1;
1005	/* Shutdown the terminal */
1006	raw3215_shutdown(raw);
1007	tasklet_kill(&raw->tlet);
1008	tty->closing = 0;
1009	tty_port_tty_set(&raw->port, NULL);
1010}
1011
1012/*
1013 * Returns the amount of free space in the output buffer.
1014 */
1015static int tty3215_write_room(struct tty_struct *tty)
1016{
1017	struct raw3215_info *raw;
1018
1019	raw = (struct raw3215_info *) tty->driver_data;
1020
1021	/* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1022	if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1023		return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1024	else
1025		return 0;
1026}
1027
1028/*
1029 * String write routine for 3215 ttys
1030 */
1031static int tty3215_write(struct tty_struct * tty,
1032			 const unsigned char *buf, int count)
1033{
1034	struct raw3215_info *raw;
1035	int i, written;
1036
1037	if (!tty)
1038		return 0;
1039	raw = (struct raw3215_info *) tty->driver_data;
1040	written = count;
1041	while (count > 0) {
1042		for (i = 0; i < count; i++)
1043			if (buf[i] == '\t' || buf[i] == '\n')
1044				break;
1045		raw3215_write(raw, buf, i);
1046		count -= i;
1047		buf += i;
1048		if (count > 0) {
1049			raw3215_putchar(raw, *buf);
1050			count--;
1051			buf++;
1052		}
1053	}
1054	return written;
1055}
1056
1057/*
1058 * Put character routine for 3215 ttys
1059 */
1060static int tty3215_put_char(struct tty_struct *tty, unsigned char ch)
1061{
1062	struct raw3215_info *raw;
1063
1064	if (!tty)
1065		return 0;
1066	raw = (struct raw3215_info *) tty->driver_data;
1067	raw3215_putchar(raw, ch);
1068	return 1;
1069}
1070
1071static void tty3215_flush_chars(struct tty_struct *tty)
1072{
1073}
1074
1075/*
1076 * Returns the number of characters in the output buffer
1077 */
1078static int tty3215_chars_in_buffer(struct tty_struct *tty)
1079{
1080	struct raw3215_info *raw;
1081
1082	raw = (struct raw3215_info *) tty->driver_data;
1083	return raw->count;
1084}
1085
1086static void tty3215_flush_buffer(struct tty_struct *tty)
1087{
1088	struct raw3215_info *raw;
1089
1090	raw = (struct raw3215_info *) tty->driver_data;
1091	raw3215_flush_buffer(raw);
1092	tty_wakeup(tty);
1093}
1094
1095/*
1096 * Disable reading from a 3215 tty
1097 */
1098static void tty3215_throttle(struct tty_struct * tty)
1099{
1100	struct raw3215_info *raw;
1101
1102	raw = (struct raw3215_info *) tty->driver_data;
1103	raw->flags |= RAW3215_THROTTLED;
1104}
1105
1106/*
1107 * Enable reading from a 3215 tty
1108 */
1109static void tty3215_unthrottle(struct tty_struct * tty)
1110{
1111	struct raw3215_info *raw;
1112	unsigned long flags;
1113
1114	raw = (struct raw3215_info *) tty->driver_data;
1115	if (raw->flags & RAW3215_THROTTLED) {
1116		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1117		raw->flags &= ~RAW3215_THROTTLED;
1118		raw3215_try_io(raw);
1119		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1120	}
1121}
1122
1123/*
1124 * Disable writing to a 3215 tty
1125 */
1126static void tty3215_stop(struct tty_struct *tty)
1127{
1128	struct raw3215_info *raw;
1129
1130	raw = (struct raw3215_info *) tty->driver_data;
1131	raw->flags |= RAW3215_STOPPED;
1132}
1133
1134/*
1135 * Enable writing to a 3215 tty
1136 */
1137static void tty3215_start(struct tty_struct *tty)
1138{
1139	struct raw3215_info *raw;
1140	unsigned long flags;
1141
1142	raw = (struct raw3215_info *) tty->driver_data;
1143	if (raw->flags & RAW3215_STOPPED) {
1144		spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1145		raw->flags &= ~RAW3215_STOPPED;
1146		raw3215_try_io(raw);
1147		spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
1148	}
1149}
1150
1151static const struct tty_operations tty3215_ops = {
1152	.install = tty3215_install,
1153	.open = tty3215_open,
1154	.close = tty3215_close,
1155	.write = tty3215_write,
1156	.put_char = tty3215_put_char,
1157	.flush_chars = tty3215_flush_chars,
1158	.write_room = tty3215_write_room,
1159	.chars_in_buffer = tty3215_chars_in_buffer,
1160	.flush_buffer = tty3215_flush_buffer,
1161	.throttle = tty3215_throttle,
1162	.unthrottle = tty3215_unthrottle,
1163	.stop = tty3215_stop,
1164	.start = tty3215_start,
1165};
1166
1167/*
1168 * 3215 tty registration code called from tty_init().
1169 * Most kernel services (incl. kmalloc) are available at this poimt.
1170 */
1171static int __init tty3215_init(void)
1172{
1173	struct tty_driver *driver;
1174	int ret;
1175
1176	if (!CONSOLE_IS_3215)
1177		return 0;
1178
1179	driver = alloc_tty_driver(NR_3215);
1180	if (!driver)
1181		return -ENOMEM;
1182
1183	ret = ccw_driver_register(&raw3215_ccw_driver);
1184	if (ret) {
1185		put_tty_driver(driver);
1186		return ret;
1187	}
1188	/*
1189	 * Initialize the tty_driver structure
1190	 * Entries in tty3215_driver that are NOT initialized:
1191	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1192	 */
1193
1194	driver->driver_name = "tty3215";
1195	driver->name = "ttyS";
1196	driver->major = TTY_MAJOR;
1197	driver->minor_start = 64;
1198	driver->type = TTY_DRIVER_TYPE_SYSTEM;
1199	driver->subtype = SYSTEM_TYPE_TTY;
1200	driver->init_termios = tty_std_termios;
1201	driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1202	driver->init_termios.c_oflag = ONLCR;
1203	driver->init_termios.c_lflag = ISIG;
1204	driver->flags = TTY_DRIVER_REAL_RAW;
1205	tty_set_operations(driver, &tty3215_ops);
1206	ret = tty_register_driver(driver);
1207	if (ret) {
1208		put_tty_driver(driver);
1209		return ret;
1210	}
1211	tty3215_driver = driver;
1212	return 0;
1213}
1214device_initcall(tty3215_init);
1215