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1/*
2 * Shared Transport Line discipline driver Core
3 * This hooks up ST KIM driver and ST LL driver
4 * Copyright (C) 2009-2010 Texas Instruments
5 * Author: Pavan Savoy <pavan_savoy@ti.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#define pr_fmt(fmt) "(stc): " fmt
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/tty.h>
26
27#include <linux/seq_file.h>
28#include <linux/skbuff.h>
29
30#include <linux/ti_wilink_st.h>
31
32extern void st_kim_recv(void *, const unsigned char *, long);
33void st_int_recv(void *, const unsigned char *, long);
34/* function pointer pointing to either,
35 * st_kim_recv during registration to receive fw download responses
36 * st_int_recv after registration to receive proto stack responses
37 */
38static void (*st_recv) (void *, const unsigned char *, long);
39
40/********************************************************************/
41static void add_channel_to_table(struct st_data_s *st_gdata,
42 struct st_proto_s *new_proto)
43{
44 pr_info("%s: id %d\n", __func__, new_proto->chnl_id);
45 /* list now has the channel id as index itself */
46 st_gdata->list[new_proto->chnl_id] = new_proto;
47 st_gdata->is_registered[new_proto->chnl_id] = true;
48}
49
50static void remove_channel_from_table(struct st_data_s *st_gdata,
51 struct st_proto_s *proto)
52{
53 pr_info("%s: id %d\n", __func__, proto->chnl_id);
54/* st_gdata->list[proto->chnl_id] = NULL; */
55 st_gdata->is_registered[proto->chnl_id] = false;
56}
57
58/*
59 * called from KIM during firmware download.
60 *
61 * This is a wrapper function to tty->ops->write_room.
62 * It returns number of free space available in
63 * uart tx buffer.
64 */
65int st_get_uart_wr_room(struct st_data_s *st_gdata)
66{
67 struct tty_struct *tty;
68 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
69 pr_err("tty unavailable to perform write");
70 return -1;
71 }
72 tty = st_gdata->tty;
73 return tty->ops->write_room(tty);
74}
75
76/* can be called in from
77 * -- KIM (during fw download)
78 * -- ST Core (during st_write)
79 *
80 * This is the internal write function - a wrapper
81 * to tty->ops->write
82 */
83int st_int_write(struct st_data_s *st_gdata,
84 const unsigned char *data, int count)
85{
86 struct tty_struct *tty;
87 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
88 pr_err("tty unavailable to perform write");
89 return -EINVAL;
90 }
91 tty = st_gdata->tty;
92#ifdef VERBOSE
93 print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
94 16, 1, data, count, 0);
95#endif
96 return tty->ops->write(tty, data, count);
97
98}
99
100/*
101 * push the skb received to relevant
102 * protocol stacks
103 */
104static void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
105{
106 pr_debug(" %s(prot:%d) ", __func__, chnl_id);
107
108 if (unlikely
109 (st_gdata == NULL || st_gdata->rx_skb == NULL
110 || st_gdata->is_registered[chnl_id] == false)) {
111 pr_err("chnl_id %d not registered, no data to send?",
112 chnl_id);
113 kfree_skb(st_gdata->rx_skb);
114 return;
115 }
116 /* this cannot fail
117 * this shouldn't take long
118 * - should be just skb_queue_tail for the
119 * protocol stack driver
120 */
121 if (likely(st_gdata->list[chnl_id]->recv != NULL)) {
122 if (unlikely
123 (st_gdata->list[chnl_id]->recv
124 (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb)
125 != 0)) {
126 pr_err(" proto stack %d's ->recv failed", chnl_id);
127 kfree_skb(st_gdata->rx_skb);
128 return;
129 }
130 } else {
131 pr_err(" proto stack %d's ->recv null", chnl_id);
132 kfree_skb(st_gdata->rx_skb);
133 }
134 return;
135}
136
137/**
138 * st_reg_complete -
139 * to call registration complete callbacks
140 * of all protocol stack drivers
141 * This function is being called with spin lock held, protocol drivers are
142 * only expected to complete their waits and do nothing more than that.
143 */
144static void st_reg_complete(struct st_data_s *st_gdata, char err)
145{
146 unsigned char i = 0;
147 pr_info(" %s ", __func__);
148 for (i = 0; i < ST_MAX_CHANNELS; i++) {
149 if (likely(st_gdata != NULL &&
150 st_gdata->is_registered[i] == true &&
151 st_gdata->list[i]->reg_complete_cb != NULL)) {
152 st_gdata->list[i]->reg_complete_cb
153 (st_gdata->list[i]->priv_data, err);
154 pr_info("protocol %d's cb sent %d\n", i, err);
155 if (err) { /* cleanup registered protocol */
156 st_gdata->is_registered[i] = false;
157 if (st_gdata->protos_registered)
158 st_gdata->protos_registered--;
159 }
160 }
161 }
162}
163
164static inline int st_check_data_len(struct st_data_s *st_gdata,
165 unsigned char chnl_id, int len)
166{
167 int room = skb_tailroom(st_gdata->rx_skb);
168
169 pr_debug("len %d room %d", len, room);
170
171 if (!len) {
172 /* Received packet has only packet header and
173 * has zero length payload. So, ask ST CORE to
174 * forward the packet to protocol driver (BT/FM/GPS)
175 */
176 st_send_frame(chnl_id, st_gdata);
177
178 } else if (len > room) {
179 /* Received packet's payload length is larger.
180 * We can't accommodate it in created skb.
181 */
182 pr_err("Data length is too large len %d room %d", len,
183 room);
184 kfree_skb(st_gdata->rx_skb);
185 } else {
186 /* Packet header has non-zero payload length and
187 * we have enough space in created skb. Lets read
188 * payload data */
189 st_gdata->rx_state = ST_W4_DATA;
190 st_gdata->rx_count = len;
191 return len;
192 }
193
194 /* Change ST state to continue to process next
195 * packet */
196 st_gdata->rx_state = ST_W4_PACKET_TYPE;
197 st_gdata->rx_skb = NULL;
198 st_gdata->rx_count = 0;
199 st_gdata->rx_chnl = 0;
200
201 return 0;
202}
203
204/**
205 * st_wakeup_ack - internal function for action when wake-up ack
206 * received
207 */
208static inline void st_wakeup_ack(struct st_data_s *st_gdata,
209 unsigned char cmd)
210{
211 struct sk_buff *waiting_skb;
212 unsigned long flags = 0;
213
214 spin_lock_irqsave(&st_gdata->lock, flags);
215 /* de-Q from waitQ and Q in txQ now that the
216 * chip is awake
217 */
218 while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
219 skb_queue_tail(&st_gdata->txq, waiting_skb);
220
221 /* state forwarded to ST LL */
222 st_ll_sleep_state(st_gdata, (unsigned long)cmd);
223 spin_unlock_irqrestore(&st_gdata->lock, flags);
224
225 /* wake up to send the recently copied skbs from waitQ */
226 st_tx_wakeup(st_gdata);
227}
228
229/**
230 * st_int_recv - ST's internal receive function.
231 * Decodes received RAW data and forwards to corresponding
232 * client drivers (Bluetooth,FM,GPS..etc).
233 * This can receive various types of packets,
234 * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
235 * CH-8 packets from FM, CH-9 packets from GPS cores.
236 */
237void st_int_recv(void *disc_data,
238 const unsigned char *data, long count)
239{
240 char *ptr;
241 struct st_proto_s *proto;
242 unsigned short payload_len = 0;
243 int len = 0;
244 unsigned char type = 0;
245 unsigned char *plen;
246 struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
247 unsigned long flags;
248
249 ptr = (char *)data;
250 /* tty_receive sent null ? */
251 if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
252 pr_err(" received null from TTY ");
253 return;
254 }
255
256 pr_debug("count %ld rx_state %ld"
257 "rx_count %ld", count, st_gdata->rx_state,
258 st_gdata->rx_count);
259
260 spin_lock_irqsave(&st_gdata->lock, flags);
261 /* Decode received bytes here */
262 while (count) {
263 if (st_gdata->rx_count) {
264 len = min_t(unsigned int, st_gdata->rx_count, count);
265 memcpy(skb_put(st_gdata->rx_skb, len), ptr, len);
266 st_gdata->rx_count -= len;
267 count -= len;
268 ptr += len;
269
270 if (st_gdata->rx_count)
271 continue;
272
273 /* Check ST RX state machine , where are we? */
274 switch (st_gdata->rx_state) {
275 /* Waiting for complete packet ? */
276 case ST_W4_DATA:
277 pr_debug("Complete pkt received");
278 /* Ask ST CORE to forward
279 * the packet to protocol driver */
280 st_send_frame(st_gdata->rx_chnl, st_gdata);
281
282 st_gdata->rx_state = ST_W4_PACKET_TYPE;
283 st_gdata->rx_skb = NULL;
284 continue;
285 /* parse the header to know details */
286 case ST_W4_HEADER:
287 proto = st_gdata->list[st_gdata->rx_chnl];
288 plen =
289 &st_gdata->rx_skb->data
290 [proto->offset_len_in_hdr];
291 pr_debug("plen pointing to %x\n", *plen);
292 if (proto->len_size == 1)/* 1 byte len field */
293 payload_len = *(unsigned char *)plen;
294 else if (proto->len_size == 2)
295 payload_len =
296 __le16_to_cpu(*(unsigned short *)plen);
297 else
298 pr_info("%s: invalid length "
299 "for id %d\n",
300 __func__, proto->chnl_id);
301 st_check_data_len(st_gdata, proto->chnl_id,
302 payload_len);
303 pr_debug("off %d, pay len %d\n",
304 proto->offset_len_in_hdr, payload_len);
305 continue;
306 } /* end of switch rx_state */
307 }
308
309 /* end of if rx_count */
310 /* Check first byte of packet and identify module
311 * owner (BT/FM/GPS) */
312 switch (*ptr) {
313 case LL_SLEEP_IND:
314 case LL_SLEEP_ACK:
315 case LL_WAKE_UP_IND:
316 pr_debug("PM packet");
317 /* this takes appropriate action based on
318 * sleep state received --
319 */
320 st_ll_sleep_state(st_gdata, *ptr);
321 /* if WAKEUP_IND collides copy from waitq to txq
322 * and assume chip awake
323 */
324 spin_unlock_irqrestore(&st_gdata->lock, flags);
325 if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
326 st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
327 spin_lock_irqsave(&st_gdata->lock, flags);
328
329 ptr++;
330 count--;
331 continue;
332 case LL_WAKE_UP_ACK:
333 pr_debug("PM packet");
334
335 spin_unlock_irqrestore(&st_gdata->lock, flags);
336 /* wake up ack received */
337 st_wakeup_ack(st_gdata, *ptr);
338 spin_lock_irqsave(&st_gdata->lock, flags);
339
340 ptr++;
341 count--;
342 continue;
343 /* Unknow packet? */
344 default:
345 type = *ptr;
346
347 /* Default case means non-HCILL packets,
348 * possibilities are packets for:
349 * (a) valid protocol - Supported Protocols within
350 * the ST_MAX_CHANNELS.
351 * (b) registered protocol - Checked by
352 * "st_gdata->list[type] == NULL)" are supported
353 * protocols only.
354 * Rules out any invalid protocol and
355 * unregistered protocols with channel ID < 16.
356 */
357
358 if ((type >= ST_MAX_CHANNELS) ||
359 (st_gdata->list[type] == NULL)) {
360 pr_err("chip/interface misbehavior: "
361 "dropping frame starting "
362 "with 0x%02x\n", type);
363 goto done;
364 }
365
366 st_gdata->rx_skb = alloc_skb(
367 st_gdata->list[type]->max_frame_size,
368 GFP_ATOMIC);
369 if (st_gdata->rx_skb == NULL) {
370 pr_err("out of memory: dropping\n");
371 goto done;
372 }
373
374 skb_reserve(st_gdata->rx_skb,
375 st_gdata->list[type]->reserve);
376 /* next 2 required for BT only */
377 st_gdata->rx_skb->cb[0] = type; /*pkt_type*/
378 st_gdata->rx_skb->cb[1] = 0; /*incoming*/
379 st_gdata->rx_chnl = *ptr;
380 st_gdata->rx_state = ST_W4_HEADER;
381 st_gdata->rx_count = st_gdata->list[type]->hdr_len;
382 pr_debug("rx_count %ld\n", st_gdata->rx_count);
383 };
384 ptr++;
385 count--;
386 }
387done:
388 spin_unlock_irqrestore(&st_gdata->lock, flags);
389 pr_debug("done %s", __func__);
390 return;
391}
392
393/**
394 * st_int_dequeue - internal de-Q function.
395 * If the previous data set was not written
396 * completely, return that skb which has the pending data.
397 * In normal cases, return top of txq.
398 */
399static struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
400{
401 struct sk_buff *returning_skb;
402
403 pr_debug("%s", __func__);
404 if (st_gdata->tx_skb != NULL) {
405 returning_skb = st_gdata->tx_skb;
406 st_gdata->tx_skb = NULL;
407 return returning_skb;
408 }
409 return skb_dequeue(&st_gdata->txq);
410}
411
412/**
413 * st_int_enqueue - internal Q-ing function.
414 * Will either Q the skb to txq or the tx_waitq
415 * depending on the ST LL state.
416 * If the chip is asleep, then Q it onto waitq and
417 * wakeup the chip.
418 * txq and waitq needs protection since the other contexts
419 * may be sending data, waking up chip.
420 */
421static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
422{
423 unsigned long flags = 0;
424
425 pr_debug("%s", __func__);
426 spin_lock_irqsave(&st_gdata->lock, flags);
427
428 switch (st_ll_getstate(st_gdata)) {
429 case ST_LL_AWAKE:
430 pr_debug("ST LL is AWAKE, sending normally");
431 skb_queue_tail(&st_gdata->txq, skb);
432 break;
433 case ST_LL_ASLEEP_TO_AWAKE:
434 skb_queue_tail(&st_gdata->tx_waitq, skb);
435 break;
436 case ST_LL_AWAKE_TO_ASLEEP:
437 pr_err("ST LL is illegal state(%ld),"
438 "purging received skb.", st_ll_getstate(st_gdata));
439 kfree_skb(skb);
440 break;
441 case ST_LL_ASLEEP:
442 skb_queue_tail(&st_gdata->tx_waitq, skb);
443 st_ll_wakeup(st_gdata);
444 break;
445 default:
446 pr_err("ST LL is illegal state(%ld),"
447 "purging received skb.", st_ll_getstate(st_gdata));
448 kfree_skb(skb);
449 break;
450 }
451
452 spin_unlock_irqrestore(&st_gdata->lock, flags);
453 pr_debug("done %s", __func__);
454 return;
455}
456
457/*
458 * internal wakeup function
459 * called from either
460 * - TTY layer when write's finished
461 * - st_write (in context of the protocol stack)
462 */
463static void work_fn_write_wakeup(struct work_struct *work)
464{
465 struct st_data_s *st_gdata = container_of(work, struct st_data_s,
466 work_write_wakeup);
467
468 st_tx_wakeup((void *)st_gdata);
469}
470void st_tx_wakeup(struct st_data_s *st_data)
471{
472 struct sk_buff *skb;
473 unsigned long flags; /* for irq save flags */
474 pr_debug("%s", __func__);
475 /* check for sending & set flag sending here */
476 if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
477 pr_debug("ST already sending");
478 /* keep sending */
479 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
480 return;
481 /* TX_WAKEUP will be checked in another
482 * context
483 */
484 }
485 do { /* come back if st_tx_wakeup is set */
486 /* woke-up to write */
487 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
488 while ((skb = st_int_dequeue(st_data))) {
489 int len;
490 spin_lock_irqsave(&st_data->lock, flags);
491 /* enable wake-up from TTY */
492 set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
493 len = st_int_write(st_data, skb->data, skb->len);
494 skb_pull(skb, len);
495 /* if skb->len = len as expected, skb->len=0 */
496 if (skb->len) {
497 /* would be the next skb to be sent */
498 st_data->tx_skb = skb;
499 spin_unlock_irqrestore(&st_data->lock, flags);
500 break;
501 }
502 kfree_skb(skb);
503 spin_unlock_irqrestore(&st_data->lock, flags);
504 }
505 /* if wake-up is set in another context- restart sending */
506 } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
507
508 /* clear flag sending */
509 clear_bit(ST_TX_SENDING, &st_data->tx_state);
510}
511
512/********************************************************************/
513/* functions called from ST KIM
514*/
515void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
516{
517 seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
518 st_gdata->protos_registered,
519 st_gdata->is_registered[0x04] == true ? 'R' : 'U',
520 st_gdata->is_registered[0x08] == true ? 'R' : 'U',
521 st_gdata->is_registered[0x09] == true ? 'R' : 'U');
522}
523
524/********************************************************************/
525/*
526 * functions called from protocol stack drivers
527 * to be EXPORT-ed
528 */
529long st_register(struct st_proto_s *new_proto)
530{
531 struct st_data_s *st_gdata;
532 long err = 0;
533 unsigned long flags = 0;
534
535 st_kim_ref(&st_gdata, 0);
536 if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
537 || new_proto->reg_complete_cb == NULL) {
538 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
539 return -EINVAL;
540 }
541
542 if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
543 pr_err("chnl_id %d not supported", new_proto->chnl_id);
544 return -EPROTONOSUPPORT;
545 }
546
547 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
548 pr_err("chnl_id %d already registered", new_proto->chnl_id);
549 return -EALREADY;
550 }
551
552 /* can be from process context only */
553 spin_lock_irqsave(&st_gdata->lock, flags);
554
555 if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
556 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id);
557 /* fw download in progress */
558
559 add_channel_to_table(st_gdata, new_proto);
560 st_gdata->protos_registered++;
561 new_proto->write = st_write;
562
563 set_bit(ST_REG_PENDING, &st_gdata->st_state);
564 spin_unlock_irqrestore(&st_gdata->lock, flags);
565 return -EINPROGRESS;
566 } else if (st_gdata->protos_registered == ST_EMPTY) {
567 pr_info(" chnl_id list empty :%d ", new_proto->chnl_id);
568 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
569 st_recv = st_kim_recv;
570
571 /* enable the ST LL - to set default chip state */
572 st_ll_enable(st_gdata);
573
574 /* release lock previously held - re-locked below */
575 spin_unlock_irqrestore(&st_gdata->lock, flags);
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 /* this is where all pending registration
600 * are signalled to be complete by calling callback functions
601 */
602 if ((st_gdata->protos_registered != ST_EMPTY) &&
603 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
604 pr_debug(" call reg complete callback ");
605 st_reg_complete(st_gdata, 0);
606 }
607 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
608
609 /* check for already registered once more,
610 * since the above check is old
611 */
612 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
613 pr_err(" proto %d already registered ",
614 new_proto->chnl_id);
615 spin_unlock_irqrestore(&st_gdata->lock, flags);
616 return -EALREADY;
617 }
618
619 add_channel_to_table(st_gdata, new_proto);
620 st_gdata->protos_registered++;
621 new_proto->write = st_write;
622 spin_unlock_irqrestore(&st_gdata->lock, flags);
623 return err;
624 }
625 /* if fw is already downloaded & new stack registers protocol */
626 else {
627 add_channel_to_table(st_gdata, new_proto);
628 st_gdata->protos_registered++;
629 new_proto->write = st_write;
630
631 /* lock already held before entering else */
632 spin_unlock_irqrestore(&st_gdata->lock, flags);
633 return err;
634 }
635}
636EXPORT_SYMBOL_GPL(st_register);
637
638/* to unregister a protocol -
639 * to be called from protocol stack driver
640 */
641long st_unregister(struct st_proto_s *proto)
642{
643 long err = 0;
644 unsigned long flags = 0;
645 struct st_data_s *st_gdata;
646
647 pr_debug("%s: %d ", __func__, proto->chnl_id);
648
649 st_kim_ref(&st_gdata, 0);
650 if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) {
651 pr_err(" chnl_id %d not supported", proto->chnl_id);
652 return -EPROTONOSUPPORT;
653 }
654
655 spin_lock_irqsave(&st_gdata->lock, flags);
656
657 if (st_gdata->is_registered[proto->chnl_id] == false) {
658 pr_err(" chnl_id %d not registered", proto->chnl_id);
659 spin_unlock_irqrestore(&st_gdata->lock, flags);
660 return -EPROTONOSUPPORT;
661 }
662
663 if (st_gdata->protos_registered)
664 st_gdata->protos_registered--;
665
666 remove_channel_from_table(st_gdata, proto);
667 spin_unlock_irqrestore(&st_gdata->lock, flags);
668
669 if ((st_gdata->protos_registered == ST_EMPTY) &&
670 (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
671 pr_info(" all chnl_ids unregistered ");
672
673 /* stop traffic on tty */
674 if (st_gdata->tty) {
675 tty_ldisc_flush(st_gdata->tty);
676 stop_tty(st_gdata->tty);
677 }
678
679 /* all chnl_ids now unregistered */
680 st_kim_stop(st_gdata->kim_data);
681 /* disable ST LL */
682 st_ll_disable(st_gdata);
683 }
684 return err;
685}
686
687/*
688 * called in protocol stack drivers
689 * via the write function pointer
690 */
691long st_write(struct sk_buff *skb)
692{
693 struct st_data_s *st_gdata;
694 long len;
695
696 st_kim_ref(&st_gdata, 0);
697 if (unlikely(skb == NULL || st_gdata == NULL
698 || st_gdata->tty == NULL)) {
699 pr_err("data/tty unavailable to perform write");
700 return -EINVAL;
701 }
702
703 pr_debug("%d to be written", skb->len);
704 len = skb->len;
705
706 /* st_ll to decide where to enqueue the skb */
707 st_int_enqueue(st_gdata, skb);
708 /* wake up */
709 st_tx_wakeup(st_gdata);
710
711 /* return number of bytes written */
712 return len;
713}
714
715/* for protocols making use of shared transport */
716EXPORT_SYMBOL_GPL(st_unregister);
717
718/********************************************************************/
719/*
720 * functions called from TTY layer
721 */
722static int st_tty_open(struct tty_struct *tty)
723{
724 int err = 0;
725 struct st_data_s *st_gdata;
726 pr_info("%s ", __func__);
727
728 st_kim_ref(&st_gdata, 0);
729 st_gdata->tty = tty;
730 tty->disc_data = st_gdata;
731
732 /* don't do an wakeup for now */
733 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
734
735 /* mem already allocated
736 */
737 tty->receive_room = 65536;
738 /* Flush any pending characters in the driver and discipline. */
739 tty_ldisc_flush(tty);
740 tty_driver_flush_buffer(tty);
741 /*
742 * signal to UIM via KIM that -
743 * installation of N_TI_WL ldisc is complete
744 */
745 st_kim_complete(st_gdata->kim_data);
746 pr_debug("done %s", __func__);
747 return err;
748}
749
750static void st_tty_close(struct tty_struct *tty)
751{
752 unsigned char i = ST_MAX_CHANNELS;
753 unsigned long flags = 0;
754 struct st_data_s *st_gdata = tty->disc_data;
755
756 pr_info("%s ", __func__);
757
758 /* TODO:
759 * if a protocol has been registered & line discipline
760 * un-installed for some reason - what should be done ?
761 */
762 spin_lock_irqsave(&st_gdata->lock, flags);
763 for (i = ST_BT; i < ST_MAX_CHANNELS; i++) {
764 if (st_gdata->is_registered[i] == true)
765 pr_err("%d not un-registered", i);
766 st_gdata->list[i] = NULL;
767 st_gdata->is_registered[i] = false;
768 }
769 st_gdata->protos_registered = 0;
770 spin_unlock_irqrestore(&st_gdata->lock, flags);
771 /*
772 * signal to UIM via KIM that -
773 * N_TI_WL ldisc is un-installed
774 */
775 st_kim_complete(st_gdata->kim_data);
776 st_gdata->tty = NULL;
777 /* Flush any pending characters in the driver and discipline. */
778 tty_ldisc_flush(tty);
779 tty_driver_flush_buffer(tty);
780
781 spin_lock_irqsave(&st_gdata->lock, flags);
782 /* empty out txq and tx_waitq */
783 skb_queue_purge(&st_gdata->txq);
784 skb_queue_purge(&st_gdata->tx_waitq);
785 /* reset the TTY Rx states of ST */
786 st_gdata->rx_count = 0;
787 st_gdata->rx_state = ST_W4_PACKET_TYPE;
788 kfree_skb(st_gdata->rx_skb);
789 st_gdata->rx_skb = NULL;
790 spin_unlock_irqrestore(&st_gdata->lock, flags);
791
792 pr_debug("%s: done ", __func__);
793}
794
795static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
796 char *tty_flags, int count)
797{
798#ifdef VERBOSE
799 print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
800 16, 1, data, count, 0);
801#endif
802
803 /*
804 * if fw download is in progress then route incoming data
805 * to KIM for validation
806 */
807 st_recv(tty->disc_data, data, count);
808 pr_debug("done %s", __func__);
809}
810
811/* wake-up function called in from the TTY layer
812 * inside the internal wakeup function will be called
813 */
814static void st_tty_wakeup(struct tty_struct *tty)
815{
816 struct st_data_s *st_gdata = tty->disc_data;
817 pr_debug("%s ", __func__);
818 /* don't do an wakeup for now */
819 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
820
821 /*
822 * schedule the internal wakeup instead of calling directly to
823 * avoid lockup (port->lock needed in tty->ops->write is
824 * already taken here
825 */
826 schedule_work(&st_gdata->work_write_wakeup);
827}
828
829static void st_tty_flush_buffer(struct tty_struct *tty)
830{
831 struct st_data_s *st_gdata = tty->disc_data;
832 pr_debug("%s ", __func__);
833
834 kfree_skb(st_gdata->tx_skb);
835 st_gdata->tx_skb = NULL;
836
837 tty_driver_flush_buffer(tty);
838 return;
839}
840
841static struct tty_ldisc_ops st_ldisc_ops = {
842 .magic = TTY_LDISC_MAGIC,
843 .name = "n_st",
844 .open = st_tty_open,
845 .close = st_tty_close,
846 .receive_buf = st_tty_receive,
847 .write_wakeup = st_tty_wakeup,
848 .flush_buffer = st_tty_flush_buffer,
849 .owner = THIS_MODULE
850};
851
852/********************************************************************/
853int st_core_init(struct st_data_s **core_data)
854{
855 struct st_data_s *st_gdata;
856 long err;
857
858 err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops);
859 if (err) {
860 pr_err("error registering %d line discipline %ld",
861 N_TI_WL, err);
862 return err;
863 }
864 pr_debug("registered n_shared line discipline");
865
866 st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
867 if (!st_gdata) {
868 pr_err("memory allocation failed");
869 err = tty_unregister_ldisc(N_TI_WL);
870 if (err)
871 pr_err("unable to un-register ldisc %ld", err);
872 err = -ENOMEM;
873 return err;
874 }
875
876 /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
877 * will be pushed in this queue for actual transmission.
878 */
879 skb_queue_head_init(&st_gdata->txq);
880 skb_queue_head_init(&st_gdata->tx_waitq);
881
882 /* Locking used in st_int_enqueue() to avoid multiple execution */
883 spin_lock_init(&st_gdata->lock);
884
885 err = st_ll_init(st_gdata);
886 if (err) {
887 pr_err("error during st_ll initialization(%ld)", err);
888 kfree(st_gdata);
889 err = tty_unregister_ldisc(N_TI_WL);
890 if (err)
891 pr_err("unable to un-register ldisc");
892 return err;
893 }
894
895 INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup);
896
897 *core_data = st_gdata;
898 return 0;
899}
900
901void st_core_exit(struct st_data_s *st_gdata)
902{
903 long err;
904 /* internal module cleanup */
905 err = st_ll_deinit(st_gdata);
906 if (err)
907 pr_err("error during deinit of ST LL %ld", err);
908
909 if (st_gdata != NULL) {
910 /* Free ST Tx Qs and skbs */
911 skb_queue_purge(&st_gdata->txq);
912 skb_queue_purge(&st_gdata->tx_waitq);
913 kfree_skb(st_gdata->rx_skb);
914 kfree_skb(st_gdata->tx_skb);
915 /* TTY ldisc cleanup */
916 err = tty_unregister_ldisc(N_TI_WL);
917 if (err)
918 pr_err("unable to un-register ldisc %ld", err);
919 /* free the global data pointer */
920 kfree(st_gdata);
921 }
922}