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