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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#include <linux/netdevice.h>
19
20/*
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 *disc_data, const u8 *ptr, size_t count);
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 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
55 pr_err("tty unavailable to perform write");
56 return -1;
57 }
58
59 return tty_write_room(st_gdata->tty);
60}
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 /*
104 * this cannot fail
105 * this shouldn't take long
106 * - should be just skb_queue_tail for the
107 * protocol stack driver
108 */
109 if (likely(st_gdata->list[chnl_id]->recv != NULL)) {
110 if (unlikely
111 (st_gdata->list[chnl_id]->recv
112 (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb)
113 != 0)) {
114 pr_err(" proto stack %d's ->recv failed", chnl_id);
115 kfree_skb(st_gdata->rx_skb);
116 return;
117 }
118 } else {
119 pr_err(" proto stack %d's ->recv null", chnl_id);
120 kfree_skb(st_gdata->rx_skb);
121 }
122 return;
123}
124
125/*
126 * st_reg_complete - 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 /*
160 * Received packet has only packet header and
161 * has zero length payload. So, ask ST CORE to
162 * forward the packet to protocol driver (BT/FM/GPS)
163 */
164 st_send_frame(chnl_id, st_gdata);
165
166 } else if (len > room) {
167 /*
168 * Received packet's payload length is larger.
169 * We can't accommodate it in created skb.
170 */
171 pr_err("Data length is too large len %d room %d", len,
172 room);
173 kfree_skb(st_gdata->rx_skb);
174 } else {
175 /*
176 * Packet header has non-zero payload length and
177 * we have enough space in created skb. Lets read
178 * payload data */
179 st_gdata->rx_state = ST_W4_DATA;
180 st_gdata->rx_count = len;
181 return len;
182 }
183
184 /* Change ST state to continue to process next packet */
185 st_gdata->rx_state = ST_W4_PACKET_TYPE;
186 st_gdata->rx_skb = NULL;
187 st_gdata->rx_count = 0;
188 st_gdata->rx_chnl = 0;
189
190 return 0;
191}
192
193/*
194 * st_wakeup_ack - internal function for action when wake-up ack
195 * received
196 */
197static inline void st_wakeup_ack(struct st_data_s *st_gdata,
198 unsigned char cmd)
199{
200 struct sk_buff *waiting_skb;
201 unsigned long flags = 0;
202
203 spin_lock_irqsave(&st_gdata->lock, flags);
204 /*
205 * de-Q from waitQ and Q in txQ now that the
206 * chip is awake
207 */
208 while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
209 skb_queue_tail(&st_gdata->txq, waiting_skb);
210
211 /* state forwarded to ST LL */
212 st_ll_sleep_state(st_gdata, (unsigned long)cmd);
213 spin_unlock_irqrestore(&st_gdata->lock, flags);
214
215 /* wake up to send the recently copied skbs from waitQ */
216 st_tx_wakeup(st_gdata);
217}
218
219/*
220 * st_int_recv - ST's internal receive function.
221 * Decodes received RAW data and forwards to corresponding
222 * client drivers (Bluetooth,FM,GPS..etc).
223 * This can receive various types of packets,
224 * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
225 * CH-8 packets from FM, CH-9 packets from GPS cores.
226 */
227static void st_int_recv(void *disc_data, const u8 *ptr, size_t count)
228{
229 struct st_proto_s *proto;
230 unsigned short payload_len = 0;
231 int len = 0;
232 unsigned char type = 0;
233 unsigned char *plen;
234 struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
235 unsigned long flags;
236
237 if (st_gdata == NULL) {
238 pr_err(" received null from TTY ");
239 return;
240 }
241
242 pr_debug("count %zu rx_state %ld"
243 "rx_count %ld", count, st_gdata->rx_state,
244 st_gdata->rx_count);
245
246 spin_lock_irqsave(&st_gdata->lock, flags);
247 /* Decode received bytes here */
248 while (count) {
249 if (st_gdata->rx_count) {
250 len = min_t(unsigned int, st_gdata->rx_count, count);
251 skb_put_data(st_gdata->rx_skb, ptr, len);
252 st_gdata->rx_count -= len;
253 count -= len;
254 ptr += len;
255
256 if (st_gdata->rx_count)
257 continue;
258
259 /* Check ST RX state machine , where are we? */
260 switch (st_gdata->rx_state) {
261 /* Waiting for complete packet ? */
262 case ST_W4_DATA:
263 pr_debug("Complete pkt received");
264 /*
265 * Ask ST CORE to forward
266 * the packet to protocol driver
267 */
268 st_send_frame(st_gdata->rx_chnl, st_gdata);
269
270 st_gdata->rx_state = ST_W4_PACKET_TYPE;
271 st_gdata->rx_skb = NULL;
272 continue;
273 /* parse the header to know details */
274 case ST_W4_HEADER:
275 proto = st_gdata->list[st_gdata->rx_chnl];
276 plen =
277 &st_gdata->rx_skb->data
278 [proto->offset_len_in_hdr];
279 pr_debug("plen pointing to %x\n", *plen);
280 if (proto->len_size == 1) /* 1 byte len field */
281 payload_len = *(unsigned char *)plen;
282 else if (proto->len_size == 2)
283 payload_len =
284 __le16_to_cpu(*(unsigned short *)plen);
285 else
286 pr_info("%s: invalid length "
287 "for id %d\n",
288 __func__, proto->chnl_id);
289 st_check_data_len(st_gdata, proto->chnl_id,
290 payload_len);
291 pr_debug("off %d, pay len %d\n",
292 proto->offset_len_in_hdr, payload_len);
293 continue;
294 } /* end of switch rx_state */
295 }
296
297 /* end of if rx_count */
298
299 /*
300 * Check first byte of packet and identify module
301 * owner (BT/FM/GPS)
302 */
303 switch (*ptr) {
304 case LL_SLEEP_IND:
305 case LL_SLEEP_ACK:
306 case LL_WAKE_UP_IND:
307 pr_debug("PM packet");
308 /*
309 * this takes appropriate action based on
310 * sleep state received --
311 */
312 st_ll_sleep_state(st_gdata, *ptr);
313 /*
314 * if WAKEUP_IND collides copy from waitq to txq
315 * and assume chip awake
316 */
317 spin_unlock_irqrestore(&st_gdata->lock, flags);
318 if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
319 st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
320 spin_lock_irqsave(&st_gdata->lock, flags);
321
322 ptr++;
323 count--;
324 continue;
325 case LL_WAKE_UP_ACK:
326 pr_debug("PM packet");
327
328 spin_unlock_irqrestore(&st_gdata->lock, flags);
329 /* wake up ack received */
330 st_wakeup_ack(st_gdata, *ptr);
331 spin_lock_irqsave(&st_gdata->lock, flags);
332
333 ptr++;
334 count--;
335 continue;
336 /* Unknown packet? */
337 default:
338 type = *ptr;
339
340 /*
341 * Default case means non-HCILL packets,
342 * possibilities are packets for:
343 * (a) valid protocol - Supported Protocols within
344 * the ST_MAX_CHANNELS.
345 * (b) registered protocol - Checked by
346 * "st_gdata->list[type] == NULL)" are supported
347 * protocols only.
348 * Rules out any invalid protocol and
349 * unregistered protocols with channel ID < 16.
350 */
351
352 if ((type >= ST_MAX_CHANNELS) ||
353 (st_gdata->list[type] == NULL)) {
354 pr_err("chip/interface misbehavior: "
355 "dropping frame starting "
356 "with 0x%02x\n", type);
357 goto done;
358 }
359
360 st_gdata->rx_skb = alloc_skb(
361 st_gdata->list[type]->max_frame_size,
362 GFP_ATOMIC);
363 if (st_gdata->rx_skb == NULL) {
364 pr_err("out of memory: dropping\n");
365 goto done;
366 }
367
368 skb_reserve(st_gdata->rx_skb,
369 st_gdata->list[type]->reserve);
370 /* next 2 required for BT only */
371 st_gdata->rx_skb->cb[0] = type; /*pkt_type*/
372 st_gdata->rx_skb->cb[1] = 0; /*incoming*/
373 st_gdata->rx_chnl = *ptr;
374 st_gdata->rx_state = ST_W4_HEADER;
375 st_gdata->rx_count = st_gdata->list[type]->hdr_len;
376 pr_debug("rx_count %ld\n", st_gdata->rx_count);
377 }
378 ptr++;
379 count--;
380 }
381done:
382 spin_unlock_irqrestore(&st_gdata->lock, flags);
383 pr_debug("done %s", __func__);
384 return;
385}
386
387/*
388 * st_int_dequeue - internal de-Q function.
389 * If the previous data set was not written
390 * completely, return that skb which has the pending data.
391 * In normal cases, return top of txq.
392 */
393static struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
394{
395 struct sk_buff *returning_skb;
396
397 pr_debug("%s", __func__);
398 if (st_gdata->tx_skb != NULL) {
399 returning_skb = st_gdata->tx_skb;
400 st_gdata->tx_skb = NULL;
401 return returning_skb;
402 }
403 return skb_dequeue(&st_gdata->txq);
404}
405
406/*
407 * st_int_enqueue - internal Q-ing function.
408 * Will either Q the skb to txq or the tx_waitq
409 * depending on the ST LL state.
410 * If the chip is asleep, then Q it onto waitq and
411 * wakeup the chip.
412 * txq and waitq needs protection since the other contexts
413 * may be sending data, waking up chip.
414 */
415static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
416{
417 unsigned long flags = 0;
418
419 pr_debug("%s", __func__);
420 spin_lock_irqsave(&st_gdata->lock, flags);
421
422 switch (st_ll_getstate(st_gdata)) {
423 case ST_LL_AWAKE:
424 pr_debug("ST LL is AWAKE, sending normally");
425 skb_queue_tail(&st_gdata->txq, skb);
426 break;
427 case ST_LL_ASLEEP_TO_AWAKE:
428 skb_queue_tail(&st_gdata->tx_waitq, skb);
429 break;
430 case ST_LL_AWAKE_TO_ASLEEP:
431 pr_err("ST LL is illegal state(%ld),"
432 "purging received skb.", st_ll_getstate(st_gdata));
433 dev_kfree_skb_irq(skb);
434 break;
435 case ST_LL_ASLEEP:
436 skb_queue_tail(&st_gdata->tx_waitq, skb);
437 st_ll_wakeup(st_gdata);
438 break;
439 default:
440 pr_err("ST LL is illegal state(%ld),"
441 "purging received skb.", st_ll_getstate(st_gdata));
442 dev_kfree_skb_irq(skb);
443 break;
444 }
445
446 spin_unlock_irqrestore(&st_gdata->lock, flags);
447 pr_debug("done %s", __func__);
448 return;
449}
450
451/*
452 * internal wakeup function
453 * called from either
454 * - TTY layer when write's finished
455 * - st_write (in context of the protocol stack)
456 */
457static void work_fn_write_wakeup(struct work_struct *work)
458{
459 struct st_data_s *st_gdata = container_of(work, struct st_data_s,
460 work_write_wakeup);
461
462 st_tx_wakeup((void *)st_gdata);
463}
464void st_tx_wakeup(struct st_data_s *st_data)
465{
466 struct sk_buff *skb;
467 unsigned long flags; /* for irq save flags */
468 pr_debug("%s", __func__);
469 /* check for sending & set flag sending here */
470 if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
471 pr_debug("ST already sending");
472 /* keep sending */
473 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
474 return;
475 /* TX_WAKEUP will be checked in another
476 * context
477 */
478 }
479 do { /* come back if st_tx_wakeup is set */
480 /* woke-up to write */
481 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
482 while ((skb = st_int_dequeue(st_data))) {
483 int len;
484 spin_lock_irqsave(&st_data->lock, flags);
485 /* enable wake-up from TTY */
486 set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
487 len = st_int_write(st_data, skb->data, skb->len);
488 skb_pull(skb, len);
489 /* if skb->len = len as expected, skb->len=0 */
490 if (skb->len) {
491 /* would be the next skb to be sent */
492 st_data->tx_skb = skb;
493 spin_unlock_irqrestore(&st_data->lock, flags);
494 break;
495 }
496 dev_kfree_skb_irq(skb);
497 spin_unlock_irqrestore(&st_data->lock, flags);
498 }
499 /* if wake-up is set in another context- restart sending */
500 } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
501
502 /* clear flag sending */
503 clear_bit(ST_TX_SENDING, &st_data->tx_state);
504}
505
506/********************************************************************/
507/* functions called from ST KIM
508*/
509void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
510{
511 seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
512 st_gdata->protos_registered,
513 st_gdata->is_registered[0x04] == true ? 'R' : 'U',
514 st_gdata->is_registered[0x08] == true ? 'R' : 'U',
515 st_gdata->is_registered[0x09] == true ? 'R' : 'U');
516}
517
518/********************************************************************/
519/*
520 * functions called from protocol stack drivers
521 * to be EXPORT-ed
522 */
523long st_register(struct st_proto_s *new_proto)
524{
525 struct st_data_s *st_gdata;
526 long err = 0;
527 unsigned long flags = 0;
528
529 st_kim_ref(&st_gdata, 0);
530 if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
531 || new_proto->reg_complete_cb == NULL) {
532 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
533 return -EINVAL;
534 }
535
536 if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
537 pr_err("chnl_id %d not supported", new_proto->chnl_id);
538 return -EPROTONOSUPPORT;
539 }
540
541 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
542 pr_err("chnl_id %d already registered", new_proto->chnl_id);
543 return -EALREADY;
544 }
545
546 /* can be from process context only */
547 spin_lock_irqsave(&st_gdata->lock, flags);
548
549 if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
550 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id);
551 /* fw download in progress */
552
553 add_channel_to_table(st_gdata, new_proto);
554 st_gdata->protos_registered++;
555 new_proto->write = st_write;
556
557 set_bit(ST_REG_PENDING, &st_gdata->st_state);
558 spin_unlock_irqrestore(&st_gdata->lock, flags);
559 return -EINPROGRESS;
560 } else if (st_gdata->protos_registered == ST_EMPTY) {
561 pr_info(" chnl_id list empty :%d ", new_proto->chnl_id);
562 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
563 st_recv = st_kim_recv;
564
565 /* enable the ST LL - to set default chip state */
566 st_ll_enable(st_gdata);
567
568 /* release lock previously held - re-locked below */
569 spin_unlock_irqrestore(&st_gdata->lock, flags);
570
571 /*
572 * this may take a while to complete
573 * since it involves BT fw download
574 */
575 err = st_kim_start(st_gdata->kim_data);
576 if (err != 0) {
577 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
578 if ((st_gdata->protos_registered != ST_EMPTY) &&
579 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
580 pr_err(" KIM failure complete callback ");
581 spin_lock_irqsave(&st_gdata->lock, flags);
582 st_reg_complete(st_gdata, err);
583 spin_unlock_irqrestore(&st_gdata->lock, flags);
584 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
585 }
586 return -EINVAL;
587 }
588
589 spin_lock_irqsave(&st_gdata->lock, flags);
590
591 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
592 st_recv = st_int_recv;
593
594 /*
595 * this is where all pending registration
596 * are signalled to be complete by calling callback functions
597 */
598 if ((st_gdata->protos_registered != ST_EMPTY) &&
599 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
600 pr_debug(" call reg complete callback ");
601 st_reg_complete(st_gdata, 0);
602 }
603 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
604
605 /*
606 * check for already registered once more,
607 * since the above check is old
608 */
609 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
610 pr_err(" proto %d already registered ",
611 new_proto->chnl_id);
612 spin_unlock_irqrestore(&st_gdata->lock, flags);
613 return -EALREADY;
614 }
615
616 add_channel_to_table(st_gdata, new_proto);
617 st_gdata->protos_registered++;
618 new_proto->write = st_write;
619 spin_unlock_irqrestore(&st_gdata->lock, flags);
620 return err;
621 }
622 /* if fw is already downloaded & new stack registers protocol */
623 else {
624 add_channel_to_table(st_gdata, new_proto);
625 st_gdata->protos_registered++;
626 new_proto->write = st_write;
627
628 /* lock already held before entering else */
629 spin_unlock_irqrestore(&st_gdata->lock, flags);
630 return err;
631 }
632}
633EXPORT_SYMBOL_GPL(st_register);
634
635/*
636 * to unregister a protocol -
637 * to be called from protocol stack driver
638 */
639long st_unregister(struct st_proto_s *proto)
640{
641 long err = 0;
642 unsigned long flags = 0;
643 struct st_data_s *st_gdata;
644
645 pr_debug("%s: %d ", __func__, proto->chnl_id);
646
647 st_kim_ref(&st_gdata, 0);
648 if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) {
649 pr_err(" chnl_id %d not supported", proto->chnl_id);
650 return -EPROTONOSUPPORT;
651 }
652
653 spin_lock_irqsave(&st_gdata->lock, flags);
654
655 if (st_gdata->is_registered[proto->chnl_id] == false) {
656 pr_err(" chnl_id %d not registered", proto->chnl_id);
657 spin_unlock_irqrestore(&st_gdata->lock, flags);
658 return -EPROTONOSUPPORT;
659 }
660
661 if (st_gdata->protos_registered)
662 st_gdata->protos_registered--;
663
664 remove_channel_from_table(st_gdata, proto);
665 spin_unlock_irqrestore(&st_gdata->lock, flags);
666
667 if ((st_gdata->protos_registered == ST_EMPTY) &&
668 (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
669 pr_info(" all chnl_ids unregistered ");
670
671 /* stop traffic on tty */
672 if (st_gdata->tty) {
673 tty_ldisc_flush(st_gdata->tty);
674 stop_tty(st_gdata->tty);
675 }
676
677 /* all chnl_ids now unregistered */
678 st_kim_stop(st_gdata->kim_data);
679 /* disable ST LL */
680 st_ll_disable(st_gdata);
681 }
682 return err;
683}
684
685/*
686 * called in protocol stack drivers
687 * via the write function pointer
688 */
689long st_write(struct sk_buff *skb)
690{
691 struct st_data_s *st_gdata;
692 long len;
693
694 st_kim_ref(&st_gdata, 0);
695 if (unlikely(skb == NULL || st_gdata == NULL
696 || st_gdata->tty == NULL)) {
697 pr_err("data/tty unavailable to perform write");
698 return -EINVAL;
699 }
700
701 pr_debug("%d to be written", skb->len);
702 len = skb->len;
703
704 /* st_ll to decide where to enqueue the skb */
705 st_int_enqueue(st_gdata, skb);
706 /* wake up */
707 st_tx_wakeup(st_gdata);
708
709 /* return number of bytes written */
710 return len;
711}
712
713/* for protocols making use of shared transport */
714EXPORT_SYMBOL_GPL(st_unregister);
715
716/********************************************************************/
717/*
718 * functions called from TTY layer
719 */
720static int st_tty_open(struct tty_struct *tty)
721{
722 struct st_data_s *st_gdata;
723 pr_info("%s ", __func__);
724
725 st_kim_ref(&st_gdata, 0);
726 st_gdata->tty = tty;
727 tty->disc_data = st_gdata;
728
729 /* don't do an wakeup for now */
730 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
731
732 /* mem already allocated
733 */
734 tty->receive_room = 65536;
735 /* Flush any pending characters in the driver and discipline. */
736 tty_ldisc_flush(tty);
737 tty_driver_flush_buffer(tty);
738 /*
739 * signal to UIM via KIM that -
740 * installation of N_TI_WL ldisc is complete
741 */
742 st_kim_complete(st_gdata->kim_data);
743 pr_debug("done %s", __func__);
744
745 return 0;
746}
747
748static void st_tty_close(struct tty_struct *tty)
749{
750 unsigned char i;
751 unsigned long flags;
752 struct st_data_s *st_gdata = tty->disc_data;
753
754 pr_info("%s ", __func__);
755
756 /*
757 * TODO:
758 * if a protocol has been registered & line discipline
759 * un-installed for some reason - what should be done ?
760 */
761 spin_lock_irqsave(&st_gdata->lock, flags);
762 for (i = ST_BT; i < ST_MAX_CHANNELS; i++) {
763 if (st_gdata->is_registered[i] == true)
764 pr_err("%d not un-registered", i);
765 st_gdata->list[i] = NULL;
766 st_gdata->is_registered[i] = false;
767 }
768 st_gdata->protos_registered = 0;
769 spin_unlock_irqrestore(&st_gdata->lock, flags);
770 /*
771 * signal to UIM via KIM that -
772 * N_TI_WL ldisc is un-installed
773 */
774 st_kim_complete(st_gdata->kim_data);
775 st_gdata->tty = NULL;
776 /* Flush any pending characters in the driver and discipline. */
777 tty_ldisc_flush(tty);
778 tty_driver_flush_buffer(tty);
779
780 spin_lock_irqsave(&st_gdata->lock, flags);
781 /* empty out txq and tx_waitq */
782 skb_queue_purge(&st_gdata->txq);
783 skb_queue_purge(&st_gdata->tx_waitq);
784 /* reset the TTY Rx states of ST */
785 st_gdata->rx_count = 0;
786 st_gdata->rx_state = ST_W4_PACKET_TYPE;
787 kfree_skb(st_gdata->rx_skb);
788 st_gdata->rx_skb = NULL;
789 spin_unlock_irqrestore(&st_gdata->lock, flags);
790
791 pr_debug("%s: done ", __func__);
792}
793
794static void st_tty_receive(struct tty_struct *tty, const u8 *data,
795 const u8 *tty_flags, size_t count)
796{
797#ifdef VERBOSE
798 print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
799 16, 1, data, count, 0);
800#endif
801
802 /*
803 * if fw download is in progress then route incoming data
804 * to KIM for validation
805 */
806 st_recv(tty->disc_data, data, count);
807 pr_debug("done %s", __func__);
808}
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 .num = N_TI_WL,
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(&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 = -ENOMEM;
870 goto err_unreg_ldisc;
871 }
872
873 /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
874 * will be pushed in this queue for actual transmission.
875 */
876 skb_queue_head_init(&st_gdata->txq);
877 skb_queue_head_init(&st_gdata->tx_waitq);
878
879 /* Locking used in st_int_enqueue() to avoid multiple execution */
880 spin_lock_init(&st_gdata->lock);
881
882 err = st_ll_init(st_gdata);
883 if (err) {
884 pr_err("error during st_ll initialization(%ld)", err);
885 goto err_free_gdata;
886 }
887
888 INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup);
889
890 *core_data = st_gdata;
891 return 0;
892err_free_gdata:
893 kfree(st_gdata);
894err_unreg_ldisc:
895 tty_unregister_ldisc(&st_ldisc_ops);
896 return err;
897}
898
899void st_core_exit(struct st_data_s *st_gdata)
900{
901 long err;
902 /* internal module cleanup */
903 err = st_ll_deinit(st_gdata);
904 if (err)
905 pr_err("error during deinit of ST LL %ld", err);
906
907 if (st_gdata != NULL) {
908 /* Free ST Tx Qs and skbs */
909 skb_queue_purge(&st_gdata->txq);
910 skb_queue_purge(&st_gdata->tx_waitq);
911 kfree_skb(st_gdata->rx_skb);
912 kfree_skb(st_gdata->tx_skb);
913 /* TTY ldisc cleanup */
914 tty_unregister_ldisc(&st_ldisc_ops);
915 /* free the global data pointer */
916 kfree(st_gdata);
917 }
918}
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/init.h>
26#include <linux/tty.h>
27
28#include <linux/seq_file.h>
29#include <linux/skbuff.h>
30
31#include <linux/ti_wilink_st.h>
32
33/* function pointer pointing to either,
34 * st_kim_recv during registration to receive fw download responses
35 * st_int_recv after registration to receive proto stack responses
36 */
37void (*st_recv) (void*, const unsigned char*, long);
38
39/********************************************************************/
40static void add_channel_to_table(struct st_data_s *st_gdata,
41 struct st_proto_s *new_proto)
42{
43 pr_info("%s: id %d\n", __func__, new_proto->chnl_id);
44 /* list now has the channel id as index itself */
45 st_gdata->list[new_proto->chnl_id] = new_proto;
46 st_gdata->is_registered[new_proto->chnl_id] = true;
47}
48
49static void remove_channel_from_table(struct st_data_s *st_gdata,
50 struct st_proto_s *proto)
51{
52 pr_info("%s: id %d\n", __func__, proto->chnl_id);
53/* st_gdata->list[proto->chnl_id] = NULL; */
54 st_gdata->is_registered[proto->chnl_id] = false;
55}
56
57/*
58 * called from KIM during firmware download.
59 *
60 * This is a wrapper function to tty->ops->write_room.
61 * It returns number of free space available in
62 * uart tx buffer.
63 */
64int st_get_uart_wr_room(struct st_data_s *st_gdata)
65{
66 struct tty_struct *tty;
67 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
68 pr_err("tty unavailable to perform write");
69 return -1;
70 }
71 tty = st_gdata->tty;
72 return tty->ops->write_room(tty);
73}
74
75/* can be called in from
76 * -- KIM (during fw download)
77 * -- ST Core (during st_write)
78 *
79 * This is the internal write function - a wrapper
80 * to tty->ops->write
81 */
82int st_int_write(struct st_data_s *st_gdata,
83 const unsigned char *data, int count)
84{
85 struct tty_struct *tty;
86 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
87 pr_err("tty unavailable to perform write");
88 return -EINVAL;
89 }
90 tty = st_gdata->tty;
91#ifdef VERBOSE
92 print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
93 16, 1, data, count, 0);
94#endif
95 return tty->ops->write(tty, data, count);
96
97}
98
99/*
100 * push the skb received to relevant
101 * protocol stacks
102 */
103void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
104{
105 pr_debug(" %s(prot:%d) ", __func__, chnl_id);
106
107 if (unlikely
108 (st_gdata == NULL || st_gdata->rx_skb == NULL
109 || st_gdata->is_registered[chnl_id] == false)) {
110 pr_err("chnl_id %d not registered, no data to send?",
111 chnl_id);
112 kfree_skb(st_gdata->rx_skb);
113 return;
114 }
115 /* this cannot fail
116 * this shouldn't take long
117 * - should be just skb_queue_tail for the
118 * protocol stack driver
119 */
120 if (likely(st_gdata->list[chnl_id]->recv != NULL)) {
121 if (unlikely
122 (st_gdata->list[chnl_id]->recv
123 (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb)
124 != 0)) {
125 pr_err(" proto stack %d's ->recv failed", chnl_id);
126 kfree_skb(st_gdata->rx_skb);
127 return;
128 }
129 } else {
130 pr_err(" proto stack %d's ->recv null", chnl_id);
131 kfree_skb(st_gdata->rx_skb);
132 }
133 return;
134}
135
136/**
137 * st_reg_complete -
138 * to call registration complete callbacks
139 * of all protocol stack drivers
140 * This function is being called with spin lock held, protocol drivers are
141 * only expected to complete their waits and do nothing more than that.
142 */
143void st_reg_complete(struct st_data_s *st_gdata, char err)
144{
145 unsigned char i = 0;
146 pr_info(" %s ", __func__);
147 for (i = 0; i < ST_MAX_CHANNELS; i++) {
148 if (likely(st_gdata != NULL &&
149 st_gdata->is_registered[i] == true &&
150 st_gdata->list[i]->reg_complete_cb != NULL)) {
151 st_gdata->list[i]->reg_complete_cb
152 (st_gdata->list[i]->priv_data, err);
153 pr_info("protocol %d's cb sent %d\n", i, err);
154 if (err) { /* cleanup registered protocol */
155 st_gdata->protos_registered--;
156 st_gdata->is_registered[i] = false;
157 }
158 }
159 }
160}
161
162static inline int st_check_data_len(struct st_data_s *st_gdata,
163 unsigned char chnl_id, int len)
164{
165 int room = skb_tailroom(st_gdata->rx_skb);
166
167 pr_debug("len %d room %d", len, room);
168
169 if (!len) {
170 /* Received packet has only packet header and
171 * has zero length payload. So, ask ST CORE to
172 * forward the packet to protocol driver (BT/FM/GPS)
173 */
174 st_send_frame(chnl_id, st_gdata);
175
176 } else if (len > room) {
177 /* Received packet's payload length is larger.
178 * We can't accommodate it in created skb.
179 */
180 pr_err("Data length is too large len %d room %d", len,
181 room);
182 kfree_skb(st_gdata->rx_skb);
183 } else {
184 /* Packet header has non-zero payload length and
185 * we have enough space in created skb. Lets read
186 * payload data */
187 st_gdata->rx_state = ST_W4_DATA;
188 st_gdata->rx_count = len;
189 return len;
190 }
191
192 /* Change ST state to continue to process next
193 * packet */
194 st_gdata->rx_state = ST_W4_PACKET_TYPE;
195 st_gdata->rx_skb = NULL;
196 st_gdata->rx_count = 0;
197 st_gdata->rx_chnl = 0;
198
199 return 0;
200}
201
202/**
203 * st_wakeup_ack - internal function for action when wake-up ack
204 * received
205 */
206static inline void st_wakeup_ack(struct st_data_s *st_gdata,
207 unsigned char cmd)
208{
209 struct sk_buff *waiting_skb;
210 unsigned long flags = 0;
211
212 spin_lock_irqsave(&st_gdata->lock, flags);
213 /* de-Q from waitQ and Q in txQ now that the
214 * chip is awake
215 */
216 while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
217 skb_queue_tail(&st_gdata->txq, waiting_skb);
218
219 /* state forwarded to ST LL */
220 st_ll_sleep_state(st_gdata, (unsigned long)cmd);
221 spin_unlock_irqrestore(&st_gdata->lock, flags);
222
223 /* wake up to send the recently copied skbs from waitQ */
224 st_tx_wakeup(st_gdata);
225}
226
227/**
228 * st_int_recv - ST's internal receive function.
229 * Decodes received RAW data and forwards to corresponding
230 * client drivers (Bluetooth,FM,GPS..etc).
231 * This can receive various types of packets,
232 * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
233 * CH-8 packets from FM, CH-9 packets from GPS cores.
234 */
235void st_int_recv(void *disc_data,
236 const unsigned char *data, long count)
237{
238 char *ptr;
239 struct st_proto_s *proto;
240 unsigned short payload_len = 0;
241 int len = 0, type = 0;
242 unsigned char *plen;
243 struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
244 unsigned long flags;
245
246 ptr = (char *)data;
247 /* tty_receive sent null ? */
248 if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
249 pr_err(" received null from TTY ");
250 return;
251 }
252
253 pr_debug("count %ld rx_state %ld"
254 "rx_count %ld", count, st_gdata->rx_state,
255 st_gdata->rx_count);
256
257 spin_lock_irqsave(&st_gdata->lock, flags);
258 /* Decode received bytes here */
259 while (count) {
260 if (st_gdata->rx_count) {
261 len = min_t(unsigned int, st_gdata->rx_count, count);
262 memcpy(skb_put(st_gdata->rx_skb, len), ptr, len);
263 st_gdata->rx_count -= len;
264 count -= len;
265 ptr += len;
266
267 if (st_gdata->rx_count)
268 continue;
269
270 /* Check ST RX state machine , where are we? */
271 switch (st_gdata->rx_state) {
272 /* Waiting for complete packet ? */
273 case ST_W4_DATA:
274 pr_debug("Complete pkt received");
275 /* Ask ST CORE to forward
276 * the packet to protocol driver */
277 st_send_frame(st_gdata->rx_chnl, st_gdata);
278
279 st_gdata->rx_state = ST_W4_PACKET_TYPE;
280 st_gdata->rx_skb = NULL;
281 continue;
282 /* parse the header to know details */
283 case ST_W4_HEADER:
284 proto = st_gdata->list[st_gdata->rx_chnl];
285 plen =
286 &st_gdata->rx_skb->data
287 [proto->offset_len_in_hdr];
288 pr_debug("plen pointing to %x\n", *plen);
289 if (proto->len_size == 1)/* 1 byte len field */
290 payload_len = *(unsigned char *)plen;
291 else if (proto->len_size == 2)
292 payload_len =
293 __le16_to_cpu(*(unsigned short *)plen);
294 else
295 pr_info("%s: invalid length "
296 "for id %d\n",
297 __func__, proto->chnl_id);
298 st_check_data_len(st_gdata, proto->chnl_id,
299 payload_len);
300 pr_debug("off %d, pay len %d\n",
301 proto->offset_len_in_hdr, payload_len);
302 continue;
303 } /* end of switch rx_state */
304 }
305
306 /* end of if rx_count */
307 /* Check first byte of packet and identify module
308 * owner (BT/FM/GPS) */
309 switch (*ptr) {
310 case LL_SLEEP_IND:
311 case LL_SLEEP_ACK:
312 case LL_WAKE_UP_IND:
313 pr_debug("PM packet");
314 /* this takes appropriate action based on
315 * sleep state received --
316 */
317 st_ll_sleep_state(st_gdata, *ptr);
318 /* if WAKEUP_IND collides copy from waitq to txq
319 * and assume chip awake
320 */
321 spin_unlock_irqrestore(&st_gdata->lock, flags);
322 if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
323 st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
324 spin_lock_irqsave(&st_gdata->lock, flags);
325
326 ptr++;
327 count--;
328 continue;
329 case LL_WAKE_UP_ACK:
330 pr_debug("PM packet");
331
332 spin_unlock_irqrestore(&st_gdata->lock, flags);
333 /* wake up ack received */
334 st_wakeup_ack(st_gdata, *ptr);
335 spin_lock_irqsave(&st_gdata->lock, flags);
336
337 ptr++;
338 count--;
339 continue;
340 /* Unknow packet? */
341 default:
342 type = *ptr;
343 if (st_gdata->list[type] == NULL) {
344 pr_err("chip/interface misbehavior dropping"
345 " frame starting with 0x%02x", type);
346 goto done;
347
348 }
349 st_gdata->rx_skb = alloc_skb(
350 st_gdata->list[type]->max_frame_size,
351 GFP_ATOMIC);
352 skb_reserve(st_gdata->rx_skb,
353 st_gdata->list[type]->reserve);
354 /* next 2 required for BT only */
355 st_gdata->rx_skb->cb[0] = type; /*pkt_type*/
356 st_gdata->rx_skb->cb[1] = 0; /*incoming*/
357 st_gdata->rx_chnl = *ptr;
358 st_gdata->rx_state = ST_W4_HEADER;
359 st_gdata->rx_count = st_gdata->list[type]->hdr_len;
360 pr_debug("rx_count %ld\n", st_gdata->rx_count);
361 };
362 ptr++;
363 count--;
364 }
365done:
366 spin_unlock_irqrestore(&st_gdata->lock, flags);
367 pr_debug("done %s", __func__);
368 return;
369}
370
371/**
372 * st_int_dequeue - internal de-Q function.
373 * If the previous data set was not written
374 * completely, return that skb which has the pending data.
375 * In normal cases, return top of txq.
376 */
377struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
378{
379 struct sk_buff *returning_skb;
380
381 pr_debug("%s", __func__);
382 if (st_gdata->tx_skb != NULL) {
383 returning_skb = st_gdata->tx_skb;
384 st_gdata->tx_skb = NULL;
385 return returning_skb;
386 }
387 return skb_dequeue(&st_gdata->txq);
388}
389
390/**
391 * st_int_enqueue - internal Q-ing function.
392 * Will either Q the skb to txq or the tx_waitq
393 * depending on the ST LL state.
394 * If the chip is asleep, then Q it onto waitq and
395 * wakeup the chip.
396 * txq and waitq needs protection since the other contexts
397 * may be sending data, waking up chip.
398 */
399void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
400{
401 unsigned long flags = 0;
402
403 pr_debug("%s", __func__);
404 spin_lock_irqsave(&st_gdata->lock, flags);
405
406 switch (st_ll_getstate(st_gdata)) {
407 case ST_LL_AWAKE:
408 pr_debug("ST LL is AWAKE, sending normally");
409 skb_queue_tail(&st_gdata->txq, skb);
410 break;
411 case ST_LL_ASLEEP_TO_AWAKE:
412 skb_queue_tail(&st_gdata->tx_waitq, skb);
413 break;
414 case ST_LL_AWAKE_TO_ASLEEP:
415 pr_err("ST LL is illegal state(%ld),"
416 "purging received skb.", st_ll_getstate(st_gdata));
417 kfree_skb(skb);
418 break;
419 case ST_LL_ASLEEP:
420 skb_queue_tail(&st_gdata->tx_waitq, skb);
421 st_ll_wakeup(st_gdata);
422 break;
423 default:
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 }
429
430 spin_unlock_irqrestore(&st_gdata->lock, flags);
431 pr_debug("done %s", __func__);
432 return;
433}
434
435/*
436 * internal wakeup function
437 * called from either
438 * - TTY layer when write's finished
439 * - st_write (in context of the protocol stack)
440 */
441void st_tx_wakeup(struct st_data_s *st_data)
442{
443 struct sk_buff *skb;
444 unsigned long flags; /* for irq save flags */
445 pr_debug("%s", __func__);
446 /* check for sending & set flag sending here */
447 if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
448 pr_debug("ST already sending");
449 /* keep sending */
450 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
451 return;
452 /* TX_WAKEUP will be checked in another
453 * context
454 */
455 }
456 do { /* come back if st_tx_wakeup is set */
457 /* woke-up to write */
458 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
459 while ((skb = st_int_dequeue(st_data))) {
460 int len;
461 spin_lock_irqsave(&st_data->lock, flags);
462 /* enable wake-up from TTY */
463 set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
464 len = st_int_write(st_data, skb->data, skb->len);
465 skb_pull(skb, len);
466 /* if skb->len = len as expected, skb->len=0 */
467 if (skb->len) {
468 /* would be the next skb to be sent */
469 st_data->tx_skb = skb;
470 spin_unlock_irqrestore(&st_data->lock, flags);
471 break;
472 }
473 kfree_skb(skb);
474 spin_unlock_irqrestore(&st_data->lock, flags);
475 }
476 /* if wake-up is set in another context- restart sending */
477 } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
478
479 /* clear flag sending */
480 clear_bit(ST_TX_SENDING, &st_data->tx_state);
481}
482
483/********************************************************************/
484/* functions called from ST KIM
485*/
486void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
487{
488 seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
489 st_gdata->protos_registered,
490 st_gdata->is_registered[0x04] == true ? 'R' : 'U',
491 st_gdata->is_registered[0x08] == true ? 'R' : 'U',
492 st_gdata->is_registered[0x09] == true ? 'R' : 'U');
493}
494
495/********************************************************************/
496/*
497 * functions called from protocol stack drivers
498 * to be EXPORT-ed
499 */
500long st_register(struct st_proto_s *new_proto)
501{
502 struct st_data_s *st_gdata;
503 long err = 0;
504 unsigned long flags = 0;
505
506 st_kim_ref(&st_gdata, 0);
507 pr_info("%s(%d) ", __func__, new_proto->chnl_id);
508 if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
509 || new_proto->reg_complete_cb == NULL) {
510 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
511 return -EINVAL;
512 }
513
514 if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
515 pr_err("chnl_id %d not supported", new_proto->chnl_id);
516 return -EPROTONOSUPPORT;
517 }
518
519 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
520 pr_err("chnl_id %d already registered", new_proto->chnl_id);
521 return -EALREADY;
522 }
523
524 /* can be from process context only */
525 spin_lock_irqsave(&st_gdata->lock, flags);
526
527 if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
528 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id);
529 /* fw download in progress */
530
531 add_channel_to_table(st_gdata, new_proto);
532 st_gdata->protos_registered++;
533 new_proto->write = st_write;
534
535 set_bit(ST_REG_PENDING, &st_gdata->st_state);
536 spin_unlock_irqrestore(&st_gdata->lock, flags);
537 return -EINPROGRESS;
538 } else if (st_gdata->protos_registered == ST_EMPTY) {
539 pr_info(" chnl_id list empty :%d ", new_proto->chnl_id);
540 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
541 st_recv = st_kim_recv;
542
543 /* enable the ST LL - to set default chip state */
544 st_ll_enable(st_gdata);
545
546 /* release lock previously held - re-locked below */
547 spin_unlock_irqrestore(&st_gdata->lock, flags);
548
549 /* this may take a while to complete
550 * since it involves BT fw download
551 */
552 err = st_kim_start(st_gdata->kim_data);
553 if (err != 0) {
554 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
555 if ((st_gdata->protos_registered != ST_EMPTY) &&
556 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
557 pr_err(" KIM failure complete callback ");
558 st_reg_complete(st_gdata, err);
559 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
560 }
561 return -EINVAL;
562 }
563
564 spin_lock_irqsave(&st_gdata->lock, flags);
565
566 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
567 st_recv = st_int_recv;
568
569 /* this is where all pending registration
570 * are signalled to be complete by calling callback functions
571 */
572 if ((st_gdata->protos_registered != ST_EMPTY) &&
573 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
574 pr_debug(" call reg complete callback ");
575 st_reg_complete(st_gdata, 0);
576 }
577 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
578
579 /* check for already registered once more,
580 * since the above check is old
581 */
582 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
583 pr_err(" proto %d already registered ",
584 new_proto->chnl_id);
585 spin_unlock_irqrestore(&st_gdata->lock, flags);
586 return -EALREADY;
587 }
588
589 add_channel_to_table(st_gdata, new_proto);
590 st_gdata->protos_registered++;
591 new_proto->write = st_write;
592 spin_unlock_irqrestore(&st_gdata->lock, flags);
593 return err;
594 }
595 /* if fw is already downloaded & new stack registers protocol */
596 else {
597 add_channel_to_table(st_gdata, new_proto);
598 st_gdata->protos_registered++;
599 new_proto->write = st_write;
600
601 /* lock already held before entering else */
602 spin_unlock_irqrestore(&st_gdata->lock, flags);
603 return err;
604 }
605 pr_debug("done %s(%d) ", __func__, new_proto->chnl_id);
606}
607EXPORT_SYMBOL_GPL(st_register);
608
609/* to unregister a protocol -
610 * to be called from protocol stack driver
611 */
612long st_unregister(struct st_proto_s *proto)
613{
614 long err = 0;
615 unsigned long flags = 0;
616 struct st_data_s *st_gdata;
617
618 pr_debug("%s: %d ", __func__, proto->chnl_id);
619
620 st_kim_ref(&st_gdata, 0);
621 if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) {
622 pr_err(" chnl_id %d not supported", proto->chnl_id);
623 return -EPROTONOSUPPORT;
624 }
625
626 spin_lock_irqsave(&st_gdata->lock, flags);
627
628 if (st_gdata->is_registered[proto->chnl_id] == false) {
629 pr_err(" chnl_id %d not registered", proto->chnl_id);
630 spin_unlock_irqrestore(&st_gdata->lock, flags);
631 return -EPROTONOSUPPORT;
632 }
633
634 st_gdata->protos_registered--;
635 remove_channel_from_table(st_gdata, proto);
636 spin_unlock_irqrestore(&st_gdata->lock, flags);
637
638 /* paranoid check */
639 if (st_gdata->protos_registered < ST_EMPTY)
640 st_gdata->protos_registered = ST_EMPTY;
641
642 if ((st_gdata->protos_registered == ST_EMPTY) &&
643 (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
644 pr_info(" all chnl_ids unregistered ");
645
646 /* stop traffic on tty */
647 if (st_gdata->tty) {
648 tty_ldisc_flush(st_gdata->tty);
649 stop_tty(st_gdata->tty);
650 }
651
652 /* all chnl_ids now unregistered */
653 st_kim_stop(st_gdata->kim_data);
654 /* disable ST LL */
655 st_ll_disable(st_gdata);
656 }
657 return err;
658}
659
660/*
661 * called in protocol stack drivers
662 * via the write function pointer
663 */
664long st_write(struct sk_buff *skb)
665{
666 struct st_data_s *st_gdata;
667 long len;
668
669 st_kim_ref(&st_gdata, 0);
670 if (unlikely(skb == NULL || st_gdata == NULL
671 || st_gdata->tty == NULL)) {
672 pr_err("data/tty unavailable to perform write");
673 return -EINVAL;
674 }
675
676 pr_debug("%d to be written", skb->len);
677 len = skb->len;
678
679 /* st_ll to decide where to enqueue the skb */
680 st_int_enqueue(st_gdata, skb);
681 /* wake up */
682 st_tx_wakeup(st_gdata);
683
684 /* return number of bytes written */
685 return len;
686}
687
688/* for protocols making use of shared transport */
689EXPORT_SYMBOL_GPL(st_unregister);
690
691/********************************************************************/
692/*
693 * functions called from TTY layer
694 */
695static int st_tty_open(struct tty_struct *tty)
696{
697 int err = 0;
698 struct st_data_s *st_gdata;
699 pr_info("%s ", __func__);
700
701 st_kim_ref(&st_gdata, 0);
702 st_gdata->tty = tty;
703 tty->disc_data = st_gdata;
704
705 /* don't do an wakeup for now */
706 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
707
708 /* mem already allocated
709 */
710 tty->receive_room = 65536;
711 /* Flush any pending characters in the driver and discipline. */
712 tty_ldisc_flush(tty);
713 tty_driver_flush_buffer(tty);
714 /*
715 * signal to UIM via KIM that -
716 * installation of N_TI_WL ldisc is complete
717 */
718 st_kim_complete(st_gdata->kim_data);
719 pr_debug("done %s", __func__);
720 return err;
721}
722
723static void st_tty_close(struct tty_struct *tty)
724{
725 unsigned char i = ST_MAX_CHANNELS;
726 unsigned long flags = 0;
727 struct st_data_s *st_gdata = tty->disc_data;
728
729 pr_info("%s ", __func__);
730
731 /* TODO:
732 * if a protocol has been registered & line discipline
733 * un-installed for some reason - what should be done ?
734 */
735 spin_lock_irqsave(&st_gdata->lock, flags);
736 for (i = ST_BT; i < ST_MAX_CHANNELS; i++) {
737 if (st_gdata->is_registered[i] == true)
738 pr_err("%d not un-registered", i);
739 st_gdata->list[i] = NULL;
740 st_gdata->is_registered[i] = false;
741 }
742 st_gdata->protos_registered = 0;
743 spin_unlock_irqrestore(&st_gdata->lock, flags);
744 /*
745 * signal to UIM via KIM that -
746 * N_TI_WL ldisc is un-installed
747 */
748 st_kim_complete(st_gdata->kim_data);
749 st_gdata->tty = NULL;
750 /* Flush any pending characters in the driver and discipline. */
751 tty_ldisc_flush(tty);
752 tty_driver_flush_buffer(tty);
753
754 spin_lock_irqsave(&st_gdata->lock, flags);
755 /* empty out txq and tx_waitq */
756 skb_queue_purge(&st_gdata->txq);
757 skb_queue_purge(&st_gdata->tx_waitq);
758 /* reset the TTY Rx states of ST */
759 st_gdata->rx_count = 0;
760 st_gdata->rx_state = ST_W4_PACKET_TYPE;
761 kfree_skb(st_gdata->rx_skb);
762 st_gdata->rx_skb = NULL;
763 spin_unlock_irqrestore(&st_gdata->lock, flags);
764
765 pr_debug("%s: done ", __func__);
766}
767
768static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
769 char *tty_flags, int count)
770{
771#ifdef VERBOSE
772 print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
773 16, 1, data, count, 0);
774#endif
775
776 /*
777 * if fw download is in progress then route incoming data
778 * to KIM for validation
779 */
780 st_recv(tty->disc_data, data, count);
781 pr_debug("done %s", __func__);
782}
783
784/* wake-up function called in from the TTY layer
785 * inside the internal wakeup function will be called
786 */
787static void st_tty_wakeup(struct tty_struct *tty)
788{
789 struct st_data_s *st_gdata = tty->disc_data;
790 pr_debug("%s ", __func__);
791 /* don't do an wakeup for now */
792 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
793
794 /* call our internal wakeup */
795 st_tx_wakeup((void *)st_gdata);
796}
797
798static void st_tty_flush_buffer(struct tty_struct *tty)
799{
800 struct st_data_s *st_gdata = tty->disc_data;
801 pr_debug("%s ", __func__);
802
803 kfree_skb(st_gdata->tx_skb);
804 st_gdata->tx_skb = NULL;
805
806 tty->ops->flush_buffer(tty);
807 return;
808}
809
810static struct tty_ldisc_ops st_ldisc_ops = {
811 .magic = TTY_LDISC_MAGIC,
812 .name = "n_st",
813 .open = st_tty_open,
814 .close = st_tty_close,
815 .receive_buf = st_tty_receive,
816 .write_wakeup = st_tty_wakeup,
817 .flush_buffer = st_tty_flush_buffer,
818 .owner = THIS_MODULE
819};
820
821/********************************************************************/
822int st_core_init(struct st_data_s **core_data)
823{
824 struct st_data_s *st_gdata;
825 long err;
826
827 err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops);
828 if (err) {
829 pr_err("error registering %d line discipline %ld",
830 N_TI_WL, err);
831 return err;
832 }
833 pr_debug("registered n_shared line discipline");
834
835 st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
836 if (!st_gdata) {
837 pr_err("memory allocation failed");
838 err = tty_unregister_ldisc(N_TI_WL);
839 if (err)
840 pr_err("unable to un-register ldisc %ld", err);
841 err = -ENOMEM;
842 return err;
843 }
844
845 /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
846 * will be pushed in this queue for actual transmission.
847 */
848 skb_queue_head_init(&st_gdata->txq);
849 skb_queue_head_init(&st_gdata->tx_waitq);
850
851 /* Locking used in st_int_enqueue() to avoid multiple execution */
852 spin_lock_init(&st_gdata->lock);
853
854 err = st_ll_init(st_gdata);
855 if (err) {
856 pr_err("error during st_ll initialization(%ld)", err);
857 kfree(st_gdata);
858 err = tty_unregister_ldisc(N_TI_WL);
859 if (err)
860 pr_err("unable to un-register ldisc");
861 return err;
862 }
863 *core_data = st_gdata;
864 return 0;
865}
866
867void st_core_exit(struct st_data_s *st_gdata)
868{
869 long err;
870 /* internal module cleanup */
871 err = st_ll_deinit(st_gdata);
872 if (err)
873 pr_err("error during deinit of ST LL %ld", err);
874
875 if (st_gdata != NULL) {
876 /* Free ST Tx Qs and skbs */
877 skb_queue_purge(&st_gdata->txq);
878 skb_queue_purge(&st_gdata->tx_waitq);
879 kfree_skb(st_gdata->rx_skb);
880 kfree_skb(st_gdata->tx_skb);
881 /* TTY ldisc cleanup */
882 err = tty_unregister_ldisc(N_TI_WL);
883 if (err)
884 pr_err("unable to un-register ldisc %ld", err);
885 /* free the global data pointer */
886 kfree(st_gdata);
887 }
888}
889
890