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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Shared Transport Line discipline driver Core
4 * This hooks up ST KIM driver and ST LL driver
5 * Copyright (C) 2009-2010 Texas Instruments
6 * Author: Pavan Savoy <pavan_savoy@ti.com>
7 */
8
9#define pr_fmt(fmt) "(stc): " fmt
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/tty.h>
13
14#include <linux/seq_file.h>
15#include <linux/skbuff.h>
16
17#include <linux/ti_wilink_st.h>
18
19extern void st_kim_recv(void *, const unsigned char *, long);
20void st_int_recv(void *, const unsigned char *, long);
21/*
22 * function pointer pointing to either,
23 * st_kim_recv during registration to receive fw download responses
24 * st_int_recv after registration to receive proto stack responses
25 */
26static void (*st_recv) (void *, const unsigned char *, long);
27
28/********************************************************************/
29static void add_channel_to_table(struct st_data_s *st_gdata,
30 struct st_proto_s *new_proto)
31{
32 pr_info("%s: id %d\n", __func__, new_proto->chnl_id);
33 /* list now has the channel id as index itself */
34 st_gdata->list[new_proto->chnl_id] = new_proto;
35 st_gdata->is_registered[new_proto->chnl_id] = true;
36}
37
38static void remove_channel_from_table(struct st_data_s *st_gdata,
39 struct st_proto_s *proto)
40{
41 pr_info("%s: id %d\n", __func__, proto->chnl_id);
42/* st_gdata->list[proto->chnl_id] = NULL; */
43 st_gdata->is_registered[proto->chnl_id] = false;
44}
45
46/*
47 * called from KIM during firmware download.
48 *
49 * This is a wrapper function to tty->ops->write_room.
50 * It returns number of free space available in
51 * uart tx buffer.
52 */
53int st_get_uart_wr_room(struct st_data_s *st_gdata)
54{
55 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
56 pr_err("tty unavailable to perform write");
57 return -1;
58 }
59
60 return tty_write_room(st_gdata->tty);
61}
62
63/*
64 * can be called in from
65 * -- KIM (during fw download)
66 * -- ST Core (during st_write)
67 *
68 * This is the internal write function - a wrapper
69 * to tty->ops->write
70 */
71int st_int_write(struct st_data_s *st_gdata,
72 const unsigned char *data, int count)
73{
74 struct tty_struct *tty;
75 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
76 pr_err("tty unavailable to perform write");
77 return -EINVAL;
78 }
79 tty = st_gdata->tty;
80#ifdef VERBOSE
81 print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
82 16, 1, data, count, 0);
83#endif
84 return tty->ops->write(tty, data, count);
85
86}
87
88/*
89 * push the skb received to relevant
90 * protocol stacks
91 */
92static void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
93{
94 pr_debug(" %s(prot:%d) ", __func__, chnl_id);
95
96 if (unlikely
97 (st_gdata == NULL || st_gdata->rx_skb == NULL
98 || st_gdata->is_registered[chnl_id] == false)) {
99 pr_err("chnl_id %d not registered, no data to send?",
100 chnl_id);
101 kfree_skb(st_gdata->rx_skb);
102 return;
103 }
104 /*
105 * this cannot fail
106 * this shouldn't take long
107 * - should be just skb_queue_tail for the
108 * protocol stack driver
109 */
110 if (likely(st_gdata->list[chnl_id]->recv != NULL)) {
111 if (unlikely
112 (st_gdata->list[chnl_id]->recv
113 (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb)
114 != 0)) {
115 pr_err(" proto stack %d's ->recv failed", chnl_id);
116 kfree_skb(st_gdata->rx_skb);
117 return;
118 }
119 } else {
120 pr_err(" proto stack %d's ->recv null", chnl_id);
121 kfree_skb(st_gdata->rx_skb);
122 }
123 return;
124}
125
126/*
127 * st_reg_complete - to call registration complete callbacks
128 * of all protocol stack drivers
129 * This function is being called with spin lock held, protocol drivers are
130 * only expected to complete their waits and do nothing more than that.
131 */
132static void st_reg_complete(struct st_data_s *st_gdata, int err)
133{
134 unsigned char i = 0;
135 pr_info(" %s ", __func__);
136 for (i = 0; i < ST_MAX_CHANNELS; i++) {
137 if (likely(st_gdata != NULL &&
138 st_gdata->is_registered[i] == true &&
139 st_gdata->list[i]->reg_complete_cb != NULL)) {
140 st_gdata->list[i]->reg_complete_cb
141 (st_gdata->list[i]->priv_data, err);
142 pr_info("protocol %d's cb sent %d\n", i, err);
143 if (err) { /* cleanup registered protocol */
144 st_gdata->is_registered[i] = false;
145 if (st_gdata->protos_registered)
146 st_gdata->protos_registered--;
147 }
148 }
149 }
150}
151
152static inline int st_check_data_len(struct st_data_s *st_gdata,
153 unsigned char chnl_id, int len)
154{
155 int room = skb_tailroom(st_gdata->rx_skb);
156
157 pr_debug("len %d room %d", len, room);
158
159 if (!len) {
160 /*
161 * Received packet has only packet header and
162 * has zero length payload. So, ask ST CORE to
163 * forward the packet to protocol driver (BT/FM/GPS)
164 */
165 st_send_frame(chnl_id, st_gdata);
166
167 } else if (len > room) {
168 /*
169 * Received packet's payload length is larger.
170 * We can't accommodate it in created skb.
171 */
172 pr_err("Data length is too large len %d room %d", len,
173 room);
174 kfree_skb(st_gdata->rx_skb);
175 } else {
176 /*
177 * Packet header has non-zero payload length and
178 * we have enough space in created skb. Lets read
179 * payload data */
180 st_gdata->rx_state = ST_W4_DATA;
181 st_gdata->rx_count = len;
182 return len;
183 }
184
185 /* Change ST state to continue to process next packet */
186 st_gdata->rx_state = ST_W4_PACKET_TYPE;
187 st_gdata->rx_skb = NULL;
188 st_gdata->rx_count = 0;
189 st_gdata->rx_chnl = 0;
190
191 return 0;
192}
193
194/*
195 * st_wakeup_ack - internal function for action when wake-up ack
196 * received
197 */
198static inline void st_wakeup_ack(struct st_data_s *st_gdata,
199 unsigned char cmd)
200{
201 struct sk_buff *waiting_skb;
202 unsigned long flags = 0;
203
204 spin_lock_irqsave(&st_gdata->lock, flags);
205 /*
206 * de-Q from waitQ and Q in txQ now that the
207 * chip is awake
208 */
209 while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
210 skb_queue_tail(&st_gdata->txq, waiting_skb);
211
212 /* state forwarded to ST LL */
213 st_ll_sleep_state(st_gdata, (unsigned long)cmd);
214 spin_unlock_irqrestore(&st_gdata->lock, flags);
215
216 /* wake up to send the recently copied skbs from waitQ */
217 st_tx_wakeup(st_gdata);
218}
219
220/*
221 * st_int_recv - ST's internal receive function.
222 * Decodes received RAW data and forwards to corresponding
223 * client drivers (Bluetooth,FM,GPS..etc).
224 * This can receive various types of packets,
225 * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
226 * CH-8 packets from FM, CH-9 packets from GPS cores.
227 */
228void st_int_recv(void *disc_data,
229 const unsigned char *data, long count)
230{
231 char *ptr;
232 struct st_proto_s *proto;
233 unsigned short payload_len = 0;
234 int len = 0;
235 unsigned char type = 0;
236 unsigned char *plen;
237 struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
238 unsigned long flags;
239
240 ptr = (char *)data;
241 /* tty_receive sent null ? */
242 if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
243 pr_err(" received null from TTY ");
244 return;
245 }
246
247 pr_debug("count %ld rx_state %ld"
248 "rx_count %ld", count, st_gdata->rx_state,
249 st_gdata->rx_count);
250
251 spin_lock_irqsave(&st_gdata->lock, flags);
252 /* Decode received bytes here */
253 while (count) {
254 if (st_gdata->rx_count) {
255 len = min_t(unsigned int, st_gdata->rx_count, count);
256 skb_put_data(st_gdata->rx_skb, ptr, len);
257 st_gdata->rx_count -= len;
258 count -= len;
259 ptr += len;
260
261 if (st_gdata->rx_count)
262 continue;
263
264 /* Check ST RX state machine , where are we? */
265 switch (st_gdata->rx_state) {
266 /* Waiting for complete packet ? */
267 case ST_W4_DATA:
268 pr_debug("Complete pkt received");
269 /*
270 * Ask ST CORE to forward
271 * the packet to protocol driver
272 */
273 st_send_frame(st_gdata->rx_chnl, st_gdata);
274
275 st_gdata->rx_state = ST_W4_PACKET_TYPE;
276 st_gdata->rx_skb = NULL;
277 continue;
278 /* parse the header to know details */
279 case ST_W4_HEADER:
280 proto = st_gdata->list[st_gdata->rx_chnl];
281 plen =
282 &st_gdata->rx_skb->data
283 [proto->offset_len_in_hdr];
284 pr_debug("plen pointing to %x\n", *plen);
285 if (proto->len_size == 1) /* 1 byte len field */
286 payload_len = *(unsigned char *)plen;
287 else if (proto->len_size == 2)
288 payload_len =
289 __le16_to_cpu(*(unsigned short *)plen);
290 else
291 pr_info("%s: invalid length "
292 "for id %d\n",
293 __func__, proto->chnl_id);
294 st_check_data_len(st_gdata, proto->chnl_id,
295 payload_len);
296 pr_debug("off %d, pay len %d\n",
297 proto->offset_len_in_hdr, payload_len);
298 continue;
299 } /* end of switch rx_state */
300 }
301
302 /* end of if rx_count */
303
304 /*
305 * Check first byte of packet and identify module
306 * owner (BT/FM/GPS)
307 */
308 switch (*ptr) {
309 case LL_SLEEP_IND:
310 case LL_SLEEP_ACK:
311 case LL_WAKE_UP_IND:
312 pr_debug("PM packet");
313 /*
314 * this takes appropriate action based on
315 * sleep state received --
316 */
317 st_ll_sleep_state(st_gdata, *ptr);
318 /*
319 * if WAKEUP_IND collides copy from waitq to txq
320 * and assume chip awake
321 */
322 spin_unlock_irqrestore(&st_gdata->lock, flags);
323 if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
324 st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
325 spin_lock_irqsave(&st_gdata->lock, flags);
326
327 ptr++;
328 count--;
329 continue;
330 case LL_WAKE_UP_ACK:
331 pr_debug("PM packet");
332
333 spin_unlock_irqrestore(&st_gdata->lock, flags);
334 /* wake up ack received */
335 st_wakeup_ack(st_gdata, *ptr);
336 spin_lock_irqsave(&st_gdata->lock, flags);
337
338 ptr++;
339 count--;
340 continue;
341 /* Unknow packet? */
342 default:
343 type = *ptr;
344
345 /*
346 * Default case means non-HCILL packets,
347 * possibilities are packets for:
348 * (a) valid protocol - Supported Protocols within
349 * the ST_MAX_CHANNELS.
350 * (b) registered protocol - Checked by
351 * "st_gdata->list[type] == NULL)" are supported
352 * protocols only.
353 * Rules out any invalid protocol and
354 * unregistered protocols with channel ID < 16.
355 */
356
357 if ((type >= ST_MAX_CHANNELS) ||
358 (st_gdata->list[type] == NULL)) {
359 pr_err("chip/interface misbehavior: "
360 "dropping frame starting "
361 "with 0x%02x\n", type);
362 goto done;
363 }
364
365 st_gdata->rx_skb = alloc_skb(
366 st_gdata->list[type]->max_frame_size,
367 GFP_ATOMIC);
368 if (st_gdata->rx_skb == NULL) {
369 pr_err("out of memory: dropping\n");
370 goto done;
371 }
372
373 skb_reserve(st_gdata->rx_skb,
374 st_gdata->list[type]->reserve);
375 /* next 2 required for BT only */
376 st_gdata->rx_skb->cb[0] = type; /*pkt_type*/
377 st_gdata->rx_skb->cb[1] = 0; /*incoming*/
378 st_gdata->rx_chnl = *ptr;
379 st_gdata->rx_state = ST_W4_HEADER;
380 st_gdata->rx_count = st_gdata->list[type]->hdr_len;
381 pr_debug("rx_count %ld\n", st_gdata->rx_count);
382 }
383 ptr++;
384 count--;
385 }
386done:
387 spin_unlock_irqrestore(&st_gdata->lock, flags);
388 pr_debug("done %s", __func__);
389 return;
390}
391
392/*
393 * st_int_dequeue - internal de-Q function.
394 * If the previous data set was not written
395 * completely, return that skb which has the pending data.
396 * In normal cases, return top of txq.
397 */
398static struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
399{
400 struct sk_buff *returning_skb;
401
402 pr_debug("%s", __func__);
403 if (st_gdata->tx_skb != NULL) {
404 returning_skb = st_gdata->tx_skb;
405 st_gdata->tx_skb = NULL;
406 return returning_skb;
407 }
408 return skb_dequeue(&st_gdata->txq);
409}
410
411/*
412 * st_int_enqueue - internal Q-ing function.
413 * Will either Q the skb to txq or the tx_waitq
414 * depending on the ST LL state.
415 * If the chip is asleep, then Q it onto waitq and
416 * wakeup the chip.
417 * txq and waitq needs protection since the other contexts
418 * may be sending data, waking up chip.
419 */
420static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
421{
422 unsigned long flags = 0;
423
424 pr_debug("%s", __func__);
425 spin_lock_irqsave(&st_gdata->lock, flags);
426
427 switch (st_ll_getstate(st_gdata)) {
428 case ST_LL_AWAKE:
429 pr_debug("ST LL is AWAKE, sending normally");
430 skb_queue_tail(&st_gdata->txq, skb);
431 break;
432 case ST_LL_ASLEEP_TO_AWAKE:
433 skb_queue_tail(&st_gdata->tx_waitq, skb);
434 break;
435 case ST_LL_AWAKE_TO_ASLEEP:
436 pr_err("ST LL is illegal state(%ld),"
437 "purging received skb.", st_ll_getstate(st_gdata));
438 kfree_skb(skb);
439 break;
440 case ST_LL_ASLEEP:
441 skb_queue_tail(&st_gdata->tx_waitq, skb);
442 st_ll_wakeup(st_gdata);
443 break;
444 default:
445 pr_err("ST LL is illegal state(%ld),"
446 "purging received skb.", st_ll_getstate(st_gdata));
447 kfree_skb(skb);
448 break;
449 }
450
451 spin_unlock_irqrestore(&st_gdata->lock, flags);
452 pr_debug("done %s", __func__);
453 return;
454}
455
456/*
457 * internal wakeup function
458 * called from either
459 * - TTY layer when write's finished
460 * - st_write (in context of the protocol stack)
461 */
462static void work_fn_write_wakeup(struct work_struct *work)
463{
464 struct st_data_s *st_gdata = container_of(work, struct st_data_s,
465 work_write_wakeup);
466
467 st_tx_wakeup((void *)st_gdata);
468}
469void st_tx_wakeup(struct st_data_s *st_data)
470{
471 struct sk_buff *skb;
472 unsigned long flags; /* for irq save flags */
473 pr_debug("%s", __func__);
474 /* check for sending & set flag sending here */
475 if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
476 pr_debug("ST already sending");
477 /* keep sending */
478 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
479 return;
480 /* TX_WAKEUP will be checked in another
481 * context
482 */
483 }
484 do { /* come back if st_tx_wakeup is set */
485 /* woke-up to write */
486 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
487 while ((skb = st_int_dequeue(st_data))) {
488 int len;
489 spin_lock_irqsave(&st_data->lock, flags);
490 /* enable wake-up from TTY */
491 set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
492 len = st_int_write(st_data, skb->data, skb->len);
493 skb_pull(skb, len);
494 /* if skb->len = len as expected, skb->len=0 */
495 if (skb->len) {
496 /* would be the next skb to be sent */
497 st_data->tx_skb = skb;
498 spin_unlock_irqrestore(&st_data->lock, flags);
499 break;
500 }
501 kfree_skb(skb);
502 spin_unlock_irqrestore(&st_data->lock, flags);
503 }
504 /* if wake-up is set in another context- restart sending */
505 } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
506
507 /* clear flag sending */
508 clear_bit(ST_TX_SENDING, &st_data->tx_state);
509}
510
511/********************************************************************/
512/* functions called from ST KIM
513*/
514void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
515{
516 seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
517 st_gdata->protos_registered,
518 st_gdata->is_registered[0x04] == true ? 'R' : 'U',
519 st_gdata->is_registered[0x08] == true ? 'R' : 'U',
520 st_gdata->is_registered[0x09] == true ? 'R' : 'U');
521}
522
523/********************************************************************/
524/*
525 * functions called from protocol stack drivers
526 * to be EXPORT-ed
527 */
528long st_register(struct st_proto_s *new_proto)
529{
530 struct st_data_s *st_gdata;
531 long err = 0;
532 unsigned long flags = 0;
533
534 st_kim_ref(&st_gdata, 0);
535 if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
536 || new_proto->reg_complete_cb == NULL) {
537 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
538 return -EINVAL;
539 }
540
541 if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
542 pr_err("chnl_id %d not supported", new_proto->chnl_id);
543 return -EPROTONOSUPPORT;
544 }
545
546 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
547 pr_err("chnl_id %d already registered", new_proto->chnl_id);
548 return -EALREADY;
549 }
550
551 /* can be from process context only */
552 spin_lock_irqsave(&st_gdata->lock, flags);
553
554 if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
555 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id);
556 /* fw download in progress */
557
558 add_channel_to_table(st_gdata, new_proto);
559 st_gdata->protos_registered++;
560 new_proto->write = st_write;
561
562 set_bit(ST_REG_PENDING, &st_gdata->st_state);
563 spin_unlock_irqrestore(&st_gdata->lock, flags);
564 return -EINPROGRESS;
565 } else if (st_gdata->protos_registered == ST_EMPTY) {
566 pr_info(" chnl_id list empty :%d ", new_proto->chnl_id);
567 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
568 st_recv = st_kim_recv;
569
570 /* enable the ST LL - to set default chip state */
571 st_ll_enable(st_gdata);
572
573 /* release lock previously held - re-locked below */
574 spin_unlock_irqrestore(&st_gdata->lock, flags);
575
576 /*
577 * this may take a while to complete
578 * since it involves BT fw download
579 */
580 err = st_kim_start(st_gdata->kim_data);
581 if (err != 0) {
582 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
583 if ((st_gdata->protos_registered != ST_EMPTY) &&
584 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
585 pr_err(" KIM failure complete callback ");
586 spin_lock_irqsave(&st_gdata->lock, flags);
587 st_reg_complete(st_gdata, err);
588 spin_unlock_irqrestore(&st_gdata->lock, flags);
589 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
590 }
591 return -EINVAL;
592 }
593
594 spin_lock_irqsave(&st_gdata->lock, flags);
595
596 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
597 st_recv = st_int_recv;
598
599 /*
600 * this is where all pending registration
601 * are signalled to be complete by calling callback functions
602 */
603 if ((st_gdata->protos_registered != ST_EMPTY) &&
604 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
605 pr_debug(" call reg complete callback ");
606 st_reg_complete(st_gdata, 0);
607 }
608 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
609
610 /*
611 * check for already registered once more,
612 * since the above check is old
613 */
614 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
615 pr_err(" proto %d already registered ",
616 new_proto->chnl_id);
617 spin_unlock_irqrestore(&st_gdata->lock, flags);
618 return -EALREADY;
619 }
620
621 add_channel_to_table(st_gdata, new_proto);
622 st_gdata->protos_registered++;
623 new_proto->write = st_write;
624 spin_unlock_irqrestore(&st_gdata->lock, flags);
625 return err;
626 }
627 /* if fw is already downloaded & new stack registers protocol */
628 else {
629 add_channel_to_table(st_gdata, new_proto);
630 st_gdata->protos_registered++;
631 new_proto->write = st_write;
632
633 /* lock already held before entering else */
634 spin_unlock_irqrestore(&st_gdata->lock, flags);
635 return err;
636 }
637}
638EXPORT_SYMBOL_GPL(st_register);
639
640/*
641 * to unregister a protocol -
642 * to be called from protocol stack driver
643 */
644long st_unregister(struct st_proto_s *proto)
645{
646 long err = 0;
647 unsigned long flags = 0;
648 struct st_data_s *st_gdata;
649
650 pr_debug("%s: %d ", __func__, proto->chnl_id);
651
652 st_kim_ref(&st_gdata, 0);
653 if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) {
654 pr_err(" chnl_id %d not supported", proto->chnl_id);
655 return -EPROTONOSUPPORT;
656 }
657
658 spin_lock_irqsave(&st_gdata->lock, flags);
659
660 if (st_gdata->is_registered[proto->chnl_id] == false) {
661 pr_err(" chnl_id %d not registered", proto->chnl_id);
662 spin_unlock_irqrestore(&st_gdata->lock, flags);
663 return -EPROTONOSUPPORT;
664 }
665
666 if (st_gdata->protos_registered)
667 st_gdata->protos_registered--;
668
669 remove_channel_from_table(st_gdata, proto);
670 spin_unlock_irqrestore(&st_gdata->lock, flags);
671
672 if ((st_gdata->protos_registered == ST_EMPTY) &&
673 (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
674 pr_info(" all chnl_ids unregistered ");
675
676 /* stop traffic on tty */
677 if (st_gdata->tty) {
678 tty_ldisc_flush(st_gdata->tty);
679 stop_tty(st_gdata->tty);
680 }
681
682 /* all chnl_ids now unregistered */
683 st_kim_stop(st_gdata->kim_data);
684 /* disable ST LL */
685 st_ll_disable(st_gdata);
686 }
687 return err;
688}
689
690/*
691 * called in protocol stack drivers
692 * via the write function pointer
693 */
694long st_write(struct sk_buff *skb)
695{
696 struct st_data_s *st_gdata;
697 long len;
698
699 st_kim_ref(&st_gdata, 0);
700 if (unlikely(skb == NULL || st_gdata == NULL
701 || st_gdata->tty == NULL)) {
702 pr_err("data/tty unavailable to perform write");
703 return -EINVAL;
704 }
705
706 pr_debug("%d to be written", skb->len);
707 len = skb->len;
708
709 /* st_ll to decide where to enqueue the skb */
710 st_int_enqueue(st_gdata, skb);
711 /* wake up */
712 st_tx_wakeup(st_gdata);
713
714 /* return number of bytes written */
715 return len;
716}
717
718/* for protocols making use of shared transport */
719EXPORT_SYMBOL_GPL(st_unregister);
720
721/********************************************************************/
722/*
723 * functions called from TTY layer
724 */
725static int st_tty_open(struct tty_struct *tty)
726{
727 struct st_data_s *st_gdata;
728 pr_info("%s ", __func__);
729
730 st_kim_ref(&st_gdata, 0);
731 st_gdata->tty = tty;
732 tty->disc_data = st_gdata;
733
734 /* don't do an wakeup for now */
735 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
736
737 /* mem already allocated
738 */
739 tty->receive_room = 65536;
740 /* Flush any pending characters in the driver and discipline. */
741 tty_ldisc_flush(tty);
742 tty_driver_flush_buffer(tty);
743 /*
744 * signal to UIM via KIM that -
745 * installation of N_TI_WL ldisc is complete
746 */
747 st_kim_complete(st_gdata->kim_data);
748 pr_debug("done %s", __func__);
749
750 return 0;
751}
752
753static void st_tty_close(struct tty_struct *tty)
754{
755 unsigned char i;
756 unsigned long flags;
757 struct st_data_s *st_gdata = tty->disc_data;
758
759 pr_info("%s ", __func__);
760
761 /*
762 * TODO:
763 * if a protocol has been registered & line discipline
764 * un-installed for some reason - what should be done ?
765 */
766 spin_lock_irqsave(&st_gdata->lock, flags);
767 for (i = ST_BT; i < ST_MAX_CHANNELS; i++) {
768 if (st_gdata->is_registered[i] == true)
769 pr_err("%d not un-registered", i);
770 st_gdata->list[i] = NULL;
771 st_gdata->is_registered[i] = false;
772 }
773 st_gdata->protos_registered = 0;
774 spin_unlock_irqrestore(&st_gdata->lock, flags);
775 /*
776 * signal to UIM via KIM that -
777 * N_TI_WL ldisc is un-installed
778 */
779 st_kim_complete(st_gdata->kim_data);
780 st_gdata->tty = NULL;
781 /* Flush any pending characters in the driver and discipline. */
782 tty_ldisc_flush(tty);
783 tty_driver_flush_buffer(tty);
784
785 spin_lock_irqsave(&st_gdata->lock, flags);
786 /* empty out txq and tx_waitq */
787 skb_queue_purge(&st_gdata->txq);
788 skb_queue_purge(&st_gdata->tx_waitq);
789 /* reset the TTY Rx states of ST */
790 st_gdata->rx_count = 0;
791 st_gdata->rx_state = ST_W4_PACKET_TYPE;
792 kfree_skb(st_gdata->rx_skb);
793 st_gdata->rx_skb = NULL;
794 spin_unlock_irqrestore(&st_gdata->lock, flags);
795
796 pr_debug("%s: done ", __func__);
797}
798
799static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
800 const char *tty_flags, int count)
801{
802#ifdef VERBOSE
803 print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
804 16, 1, data, count, 0);
805#endif
806
807 /*
808 * if fw download is in progress then route incoming data
809 * to KIM for validation
810 */
811 st_recv(tty->disc_data, data, count);
812 pr_debug("done %s", __func__);
813}
814
815/*
816 * wake-up function called in from the TTY layer
817 * inside the internal wakeup function will be called
818 */
819static void st_tty_wakeup(struct tty_struct *tty)
820{
821 struct st_data_s *st_gdata = tty->disc_data;
822 pr_debug("%s ", __func__);
823 /* don't do an wakeup for now */
824 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
825
826 /*
827 * schedule the internal wakeup instead of calling directly to
828 * avoid lockup (port->lock needed in tty->ops->write is
829 * already taken here
830 */
831 schedule_work(&st_gdata->work_write_wakeup);
832}
833
834static void st_tty_flush_buffer(struct tty_struct *tty)
835{
836 struct st_data_s *st_gdata = tty->disc_data;
837 pr_debug("%s ", __func__);
838
839 kfree_skb(st_gdata->tx_skb);
840 st_gdata->tx_skb = NULL;
841
842 tty_driver_flush_buffer(tty);
843 return;
844}
845
846static struct tty_ldisc_ops st_ldisc_ops = {
847 .num = N_TI_WL,
848 .name = "n_st",
849 .open = st_tty_open,
850 .close = st_tty_close,
851 .receive_buf = st_tty_receive,
852 .write_wakeup = st_tty_wakeup,
853 .flush_buffer = st_tty_flush_buffer,
854 .owner = THIS_MODULE
855};
856
857/********************************************************************/
858int st_core_init(struct st_data_s **core_data)
859{
860 struct st_data_s *st_gdata;
861 long err;
862
863 err = tty_register_ldisc(&st_ldisc_ops);
864 if (err) {
865 pr_err("error registering %d line discipline %ld",
866 N_TI_WL, err);
867 return err;
868 }
869 pr_debug("registered n_shared line discipline");
870
871 st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
872 if (!st_gdata) {
873 pr_err("memory allocation failed");
874 err = -ENOMEM;
875 goto err_unreg_ldisc;
876 }
877
878 /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
879 * will be pushed in this queue for actual transmission.
880 */
881 skb_queue_head_init(&st_gdata->txq);
882 skb_queue_head_init(&st_gdata->tx_waitq);
883
884 /* Locking used in st_int_enqueue() to avoid multiple execution */
885 spin_lock_init(&st_gdata->lock);
886
887 err = st_ll_init(st_gdata);
888 if (err) {
889 pr_err("error during st_ll initialization(%ld)", err);
890 goto err_free_gdata;
891 }
892
893 INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup);
894
895 *core_data = st_gdata;
896 return 0;
897err_free_gdata:
898 kfree(st_gdata);
899err_unreg_ldisc:
900 tty_unregister_ldisc(&st_ldisc_ops);
901 return err;
902}
903
904void st_core_exit(struct st_data_s *st_gdata)
905{
906 long err;
907 /* internal module cleanup */
908 err = st_ll_deinit(st_gdata);
909 if (err)
910 pr_err("error during deinit of ST LL %ld", err);
911
912 if (st_gdata != NULL) {
913 /* Free ST Tx Qs and skbs */
914 skb_queue_purge(&st_gdata->txq);
915 skb_queue_purge(&st_gdata->tx_waitq);
916 kfree_skb(st_gdata->rx_skb);
917 kfree_skb(st_gdata->tx_skb);
918 /* TTY ldisc cleanup */
919 tty_unregister_ldisc(&st_ldisc_ops);
920 /* free the global data pointer */
921 kfree(st_gdata);
922 }
923}