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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Shared Transport Line discipline driver Core
4 * This hooks up ST KIM driver and ST LL driver
5 * Copyright (C) 2009-2010 Texas Instruments
6 * Author: Pavan Savoy <pavan_savoy@ti.com>
7 */
8
9#define pr_fmt(fmt) "(stc): " fmt
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/tty.h>
13
14#include <linux/seq_file.h>
15#include <linux/skbuff.h>
16
17#include <linux/ti_wilink_st.h>
18
19extern void st_kim_recv(void *, const unsigned char *, long);
20void st_int_recv(void *, const unsigned char *, long);
21/*
22 * function pointer pointing to either,
23 * st_kim_recv during registration to receive fw download responses
24 * st_int_recv after registration to receive proto stack responses
25 */
26static void (*st_recv) (void *, const unsigned char *, long);
27
28/********************************************************************/
29static void add_channel_to_table(struct st_data_s *st_gdata,
30 struct st_proto_s *new_proto)
31{
32 pr_info("%s: id %d\n", __func__, new_proto->chnl_id);
33 /* list now has the channel id as index itself */
34 st_gdata->list[new_proto->chnl_id] = new_proto;
35 st_gdata->is_registered[new_proto->chnl_id] = true;
36}
37
38static void remove_channel_from_table(struct st_data_s *st_gdata,
39 struct st_proto_s *proto)
40{
41 pr_info("%s: id %d\n", __func__, proto->chnl_id);
42/* st_gdata->list[proto->chnl_id] = NULL; */
43 st_gdata->is_registered[proto->chnl_id] = false;
44}
45
46/*
47 * called from KIM during firmware download.
48 *
49 * This is a wrapper function to tty->ops->write_room.
50 * It returns number of free space available in
51 * uart tx buffer.
52 */
53int st_get_uart_wr_room(struct st_data_s *st_gdata)
54{
55 struct tty_struct *tty;
56 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
57 pr_err("tty unavailable to perform write");
58 return -1;
59 }
60 tty = st_gdata->tty;
61 return tty->ops->write_room(tty);
62}
63
64/*
65 * can be called in from
66 * -- KIM (during fw download)
67 * -- ST Core (during st_write)
68 *
69 * This is the internal write function - a wrapper
70 * to tty->ops->write
71 */
72int st_int_write(struct st_data_s *st_gdata,
73 const unsigned char *data, int count)
74{
75 struct tty_struct *tty;
76 if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
77 pr_err("tty unavailable to perform write");
78 return -EINVAL;
79 }
80 tty = st_gdata->tty;
81#ifdef VERBOSE
82 print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
83 16, 1, data, count, 0);
84#endif
85 return tty->ops->write(tty, data, count);
86
87}
88
89/*
90 * push the skb received to relevant
91 * protocol stacks
92 */
93static void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
94{
95 pr_debug(" %s(prot:%d) ", __func__, chnl_id);
96
97 if (unlikely
98 (st_gdata == NULL || st_gdata->rx_skb == NULL
99 || st_gdata->is_registered[chnl_id] == false)) {
100 pr_err("chnl_id %d not registered, no data to send?",
101 chnl_id);
102 kfree_skb(st_gdata->rx_skb);
103 return;
104 }
105 /*
106 * this cannot fail
107 * this shouldn't take long
108 * - should be just skb_queue_tail for the
109 * protocol stack driver
110 */
111 if (likely(st_gdata->list[chnl_id]->recv != NULL)) {
112 if (unlikely
113 (st_gdata->list[chnl_id]->recv
114 (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb)
115 != 0)) {
116 pr_err(" proto stack %d's ->recv failed", chnl_id);
117 kfree_skb(st_gdata->rx_skb);
118 return;
119 }
120 } else {
121 pr_err(" proto stack %d's ->recv null", chnl_id);
122 kfree_skb(st_gdata->rx_skb);
123 }
124 return;
125}
126
127/*
128 * st_reg_complete - to call registration complete callbacks
129 * of all protocol stack drivers
130 * This function is being called with spin lock held, protocol drivers are
131 * only expected to complete their waits and do nothing more than that.
132 */
133static void st_reg_complete(struct st_data_s *st_gdata, int err)
134{
135 unsigned char i = 0;
136 pr_info(" %s ", __func__);
137 for (i = 0; i < ST_MAX_CHANNELS; i++) {
138 if (likely(st_gdata != NULL &&
139 st_gdata->is_registered[i] == true &&
140 st_gdata->list[i]->reg_complete_cb != NULL)) {
141 st_gdata->list[i]->reg_complete_cb
142 (st_gdata->list[i]->priv_data, err);
143 pr_info("protocol %d's cb sent %d\n", i, err);
144 if (err) { /* cleanup registered protocol */
145 st_gdata->is_registered[i] = false;
146 if (st_gdata->protos_registered)
147 st_gdata->protos_registered--;
148 }
149 }
150 }
151}
152
153static inline int st_check_data_len(struct st_data_s *st_gdata,
154 unsigned char chnl_id, int len)
155{
156 int room = skb_tailroom(st_gdata->rx_skb);
157
158 pr_debug("len %d room %d", len, room);
159
160 if (!len) {
161 /*
162 * Received packet has only packet header and
163 * has zero length payload. So, ask ST CORE to
164 * forward the packet to protocol driver (BT/FM/GPS)
165 */
166 st_send_frame(chnl_id, st_gdata);
167
168 } else if (len > room) {
169 /*
170 * Received packet's payload length is larger.
171 * We can't accommodate it in created skb.
172 */
173 pr_err("Data length is too large len %d room %d", len,
174 room);
175 kfree_skb(st_gdata->rx_skb);
176 } else {
177 /*
178 * Packet header has non-zero payload length and
179 * we have enough space in created skb. Lets read
180 * payload data */
181 st_gdata->rx_state = ST_W4_DATA;
182 st_gdata->rx_count = len;
183 return len;
184 }
185
186 /* Change ST state to continue to process next packet */
187 st_gdata->rx_state = ST_W4_PACKET_TYPE;
188 st_gdata->rx_skb = NULL;
189 st_gdata->rx_count = 0;
190 st_gdata->rx_chnl = 0;
191
192 return 0;
193}
194
195/*
196 * st_wakeup_ack - internal function for action when wake-up ack
197 * received
198 */
199static inline void st_wakeup_ack(struct st_data_s *st_gdata,
200 unsigned char cmd)
201{
202 struct sk_buff *waiting_skb;
203 unsigned long flags = 0;
204
205 spin_lock_irqsave(&st_gdata->lock, flags);
206 /*
207 * de-Q from waitQ and Q in txQ now that the
208 * chip is awake
209 */
210 while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
211 skb_queue_tail(&st_gdata->txq, waiting_skb);
212
213 /* state forwarded to ST LL */
214 st_ll_sleep_state(st_gdata, (unsigned long)cmd);
215 spin_unlock_irqrestore(&st_gdata->lock, flags);
216
217 /* wake up to send the recently copied skbs from waitQ */
218 st_tx_wakeup(st_gdata);
219}
220
221/*
222 * st_int_recv - ST's internal receive function.
223 * Decodes received RAW data and forwards to corresponding
224 * client drivers (Bluetooth,FM,GPS..etc).
225 * This can receive various types of packets,
226 * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
227 * CH-8 packets from FM, CH-9 packets from GPS cores.
228 */
229void st_int_recv(void *disc_data,
230 const unsigned char *data, long count)
231{
232 char *ptr;
233 struct st_proto_s *proto;
234 unsigned short payload_len = 0;
235 int len = 0;
236 unsigned char type = 0;
237 unsigned char *plen;
238 struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
239 unsigned long flags;
240
241 ptr = (char *)data;
242 /* tty_receive sent null ? */
243 if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
244 pr_err(" received null from TTY ");
245 return;
246 }
247
248 pr_debug("count %ld rx_state %ld"
249 "rx_count %ld", count, st_gdata->rx_state,
250 st_gdata->rx_count);
251
252 spin_lock_irqsave(&st_gdata->lock, flags);
253 /* Decode received bytes here */
254 while (count) {
255 if (st_gdata->rx_count) {
256 len = min_t(unsigned int, st_gdata->rx_count, count);
257 skb_put_data(st_gdata->rx_skb, ptr, len);
258 st_gdata->rx_count -= len;
259 count -= len;
260 ptr += len;
261
262 if (st_gdata->rx_count)
263 continue;
264
265 /* Check ST RX state machine , where are we? */
266 switch (st_gdata->rx_state) {
267 /* Waiting for complete packet ? */
268 case ST_W4_DATA:
269 pr_debug("Complete pkt received");
270 /*
271 * Ask ST CORE to forward
272 * the packet to protocol driver
273 */
274 st_send_frame(st_gdata->rx_chnl, st_gdata);
275
276 st_gdata->rx_state = ST_W4_PACKET_TYPE;
277 st_gdata->rx_skb = NULL;
278 continue;
279 /* parse the header to know details */
280 case ST_W4_HEADER:
281 proto = st_gdata->list[st_gdata->rx_chnl];
282 plen =
283 &st_gdata->rx_skb->data
284 [proto->offset_len_in_hdr];
285 pr_debug("plen pointing to %x\n", *plen);
286 if (proto->len_size == 1) /* 1 byte len field */
287 payload_len = *(unsigned char *)plen;
288 else if (proto->len_size == 2)
289 payload_len =
290 __le16_to_cpu(*(unsigned short *)plen);
291 else
292 pr_info("%s: invalid length "
293 "for id %d\n",
294 __func__, proto->chnl_id);
295 st_check_data_len(st_gdata, proto->chnl_id,
296 payload_len);
297 pr_debug("off %d, pay len %d\n",
298 proto->offset_len_in_hdr, payload_len);
299 continue;
300 } /* end of switch rx_state */
301 }
302
303 /* end of if rx_count */
304
305 /*
306 * Check first byte of packet and identify module
307 * owner (BT/FM/GPS)
308 */
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 /*
315 * this takes appropriate action based on
316 * sleep state received --
317 */
318 st_ll_sleep_state(st_gdata, *ptr);
319 /*
320 * if WAKEUP_IND collides copy from waitq to txq
321 * and assume chip awake
322 */
323 spin_unlock_irqrestore(&st_gdata->lock, flags);
324 if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
325 st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
326 spin_lock_irqsave(&st_gdata->lock, flags);
327
328 ptr++;
329 count--;
330 continue;
331 case LL_WAKE_UP_ACK:
332 pr_debug("PM packet");
333
334 spin_unlock_irqrestore(&st_gdata->lock, flags);
335 /* wake up ack received */
336 st_wakeup_ack(st_gdata, *ptr);
337 spin_lock_irqsave(&st_gdata->lock, flags);
338
339 ptr++;
340 count--;
341 continue;
342 /* Unknow packet? */
343 default:
344 type = *ptr;
345
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 /*
578 * this may take a while to complete
579 * since it involves BT fw download
580 */
581 err = st_kim_start(st_gdata->kim_data);
582 if (err != 0) {
583 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
584 if ((st_gdata->protos_registered != ST_EMPTY) &&
585 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
586 pr_err(" KIM failure complete callback ");
587 spin_lock_irqsave(&st_gdata->lock, flags);
588 st_reg_complete(st_gdata, err);
589 spin_unlock_irqrestore(&st_gdata->lock, flags);
590 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
591 }
592 return -EINVAL;
593 }
594
595 spin_lock_irqsave(&st_gdata->lock, flags);
596
597 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
598 st_recv = st_int_recv;
599
600 /*
601 * this is where all pending registration
602 * are signalled to be complete by calling callback functions
603 */
604 if ((st_gdata->protos_registered != ST_EMPTY) &&
605 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
606 pr_debug(" call reg complete callback ");
607 st_reg_complete(st_gdata, 0);
608 }
609 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
610
611 /*
612 * check for already registered once more,
613 * since the above check is old
614 */
615 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
616 pr_err(" proto %d already registered ",
617 new_proto->chnl_id);
618 spin_unlock_irqrestore(&st_gdata->lock, flags);
619 return -EALREADY;
620 }
621
622 add_channel_to_table(st_gdata, new_proto);
623 st_gdata->protos_registered++;
624 new_proto->write = st_write;
625 spin_unlock_irqrestore(&st_gdata->lock, flags);
626 return err;
627 }
628 /* if fw is already downloaded & new stack registers protocol */
629 else {
630 add_channel_to_table(st_gdata, new_proto);
631 st_gdata->protos_registered++;
632 new_proto->write = st_write;
633
634 /* lock already held before entering else */
635 spin_unlock_irqrestore(&st_gdata->lock, flags);
636 return err;
637 }
638}
639EXPORT_SYMBOL_GPL(st_register);
640
641/*
642 * to unregister a protocol -
643 * to be called from protocol stack driver
644 */
645long st_unregister(struct st_proto_s *proto)
646{
647 long err = 0;
648 unsigned long flags = 0;
649 struct st_data_s *st_gdata;
650
651 pr_debug("%s: %d ", __func__, proto->chnl_id);
652
653 st_kim_ref(&st_gdata, 0);
654 if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) {
655 pr_err(" chnl_id %d not supported", proto->chnl_id);
656 return -EPROTONOSUPPORT;
657 }
658
659 spin_lock_irqsave(&st_gdata->lock, flags);
660
661 if (st_gdata->is_registered[proto->chnl_id] == false) {
662 pr_err(" chnl_id %d not registered", proto->chnl_id);
663 spin_unlock_irqrestore(&st_gdata->lock, flags);
664 return -EPROTONOSUPPORT;
665 }
666
667 if (st_gdata->protos_registered)
668 st_gdata->protos_registered--;
669
670 remove_channel_from_table(st_gdata, proto);
671 spin_unlock_irqrestore(&st_gdata->lock, flags);
672
673 if ((st_gdata->protos_registered == ST_EMPTY) &&
674 (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
675 pr_info(" all chnl_ids unregistered ");
676
677 /* stop traffic on tty */
678 if (st_gdata->tty) {
679 tty_ldisc_flush(st_gdata->tty);
680 stop_tty(st_gdata->tty);
681 }
682
683 /* all chnl_ids now unregistered */
684 st_kim_stop(st_gdata->kim_data);
685 /* disable ST LL */
686 st_ll_disable(st_gdata);
687 }
688 return err;
689}
690
691/*
692 * called in protocol stack drivers
693 * via the write function pointer
694 */
695long st_write(struct sk_buff *skb)
696{
697 struct st_data_s *st_gdata;
698 long len;
699
700 st_kim_ref(&st_gdata, 0);
701 if (unlikely(skb == NULL || st_gdata == NULL
702 || st_gdata->tty == NULL)) {
703 pr_err("data/tty unavailable to perform write");
704 return -EINVAL;
705 }
706
707 pr_debug("%d to be written", skb->len);
708 len = skb->len;
709
710 /* st_ll to decide where to enqueue the skb */
711 st_int_enqueue(st_gdata, skb);
712 /* wake up */
713 st_tx_wakeup(st_gdata);
714
715 /* return number of bytes written */
716 return len;
717}
718
719/* for protocols making use of shared transport */
720EXPORT_SYMBOL_GPL(st_unregister);
721
722/********************************************************************/
723/*
724 * functions called from TTY layer
725 */
726static int st_tty_open(struct tty_struct *tty)
727{
728 struct st_data_s *st_gdata;
729 pr_info("%s ", __func__);
730
731 st_kim_ref(&st_gdata, 0);
732 st_gdata->tty = tty;
733 tty->disc_data = st_gdata;
734
735 /* don't do an wakeup for now */
736 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
737
738 /* mem already allocated
739 */
740 tty->receive_room = 65536;
741 /* Flush any pending characters in the driver and discipline. */
742 tty_ldisc_flush(tty);
743 tty_driver_flush_buffer(tty);
744 /*
745 * signal to UIM via KIM that -
746 * installation of N_TI_WL ldisc is complete
747 */
748 st_kim_complete(st_gdata->kim_data);
749 pr_debug("done %s", __func__);
750
751 return 0;
752}
753
754static void st_tty_close(struct tty_struct *tty)
755{
756 unsigned char i;
757 unsigned long flags;
758 struct st_data_s *st_gdata = tty->disc_data;
759
760 pr_info("%s ", __func__);
761
762 /*
763 * TODO:
764 * if a protocol has been registered & line discipline
765 * un-installed for some reason - what should be done ?
766 */
767 spin_lock_irqsave(&st_gdata->lock, flags);
768 for (i = ST_BT; i < ST_MAX_CHANNELS; i++) {
769 if (st_gdata->is_registered[i] == true)
770 pr_err("%d not un-registered", i);
771 st_gdata->list[i] = NULL;
772 st_gdata->is_registered[i] = false;
773 }
774 st_gdata->protos_registered = 0;
775 spin_unlock_irqrestore(&st_gdata->lock, flags);
776 /*
777 * signal to UIM via KIM that -
778 * N_TI_WL ldisc is un-installed
779 */
780 st_kim_complete(st_gdata->kim_data);
781 st_gdata->tty = NULL;
782 /* Flush any pending characters in the driver and discipline. */
783 tty_ldisc_flush(tty);
784 tty_driver_flush_buffer(tty);
785
786 spin_lock_irqsave(&st_gdata->lock, flags);
787 /* empty out txq and tx_waitq */
788 skb_queue_purge(&st_gdata->txq);
789 skb_queue_purge(&st_gdata->tx_waitq);
790 /* reset the TTY Rx states of ST */
791 st_gdata->rx_count = 0;
792 st_gdata->rx_state = ST_W4_PACKET_TYPE;
793 kfree_skb(st_gdata->rx_skb);
794 st_gdata->rx_skb = NULL;
795 spin_unlock_irqrestore(&st_gdata->lock, flags);
796
797 pr_debug("%s: done ", __func__);
798}
799
800static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
801 char *tty_flags, int count)
802{
803#ifdef VERBOSE
804 print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
805 16, 1, data, count, 0);
806#endif
807
808 /*
809 * if fw download is in progress then route incoming data
810 * to KIM for validation
811 */
812 st_recv(tty->disc_data, data, count);
813 pr_debug("done %s", __func__);
814}
815
816/*
817 * wake-up function called in from the TTY layer
818 * inside the internal wakeup function will be called
819 */
820static void st_tty_wakeup(struct tty_struct *tty)
821{
822 struct st_data_s *st_gdata = tty->disc_data;
823 pr_debug("%s ", __func__);
824 /* don't do an wakeup for now */
825 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
826
827 /*
828 * schedule the internal wakeup instead of calling directly to
829 * avoid lockup (port->lock needed in tty->ops->write is
830 * already taken here
831 */
832 schedule_work(&st_gdata->work_write_wakeup);
833}
834
835static void st_tty_flush_buffer(struct tty_struct *tty)
836{
837 struct st_data_s *st_gdata = tty->disc_data;
838 pr_debug("%s ", __func__);
839
840 kfree_skb(st_gdata->tx_skb);
841 st_gdata->tx_skb = NULL;
842
843 tty_driver_flush_buffer(tty);
844 return;
845}
846
847static struct tty_ldisc_ops st_ldisc_ops = {
848 .magic = TTY_LDISC_MAGIC,
849 .name = "n_st",
850 .open = st_tty_open,
851 .close = st_tty_close,
852 .receive_buf = st_tty_receive,
853 .write_wakeup = st_tty_wakeup,
854 .flush_buffer = st_tty_flush_buffer,
855 .owner = THIS_MODULE
856};
857
858/********************************************************************/
859int st_core_init(struct st_data_s **core_data)
860{
861 struct st_data_s *st_gdata;
862 long err;
863
864 err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops);
865 if (err) {
866 pr_err("error registering %d line discipline %ld",
867 N_TI_WL, err);
868 return err;
869 }
870 pr_debug("registered n_shared line discipline");
871
872 st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
873 if (!st_gdata) {
874 pr_err("memory allocation failed");
875 err = tty_unregister_ldisc(N_TI_WL);
876 if (err)
877 pr_err("unable to un-register ldisc %ld", err);
878 err = -ENOMEM;
879 return err;
880 }
881
882 /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
883 * will be pushed in this queue for actual transmission.
884 */
885 skb_queue_head_init(&st_gdata->txq);
886 skb_queue_head_init(&st_gdata->tx_waitq);
887
888 /* Locking used in st_int_enqueue() to avoid multiple execution */
889 spin_lock_init(&st_gdata->lock);
890
891 err = st_ll_init(st_gdata);
892 if (err) {
893 pr_err("error during st_ll initialization(%ld)", err);
894 kfree(st_gdata);
895 err = tty_unregister_ldisc(N_TI_WL);
896 if (err)
897 pr_err("unable to un-register ldisc");
898 return err;
899 }
900
901 INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup);
902
903 *core_data = st_gdata;
904 return 0;
905}
906
907void st_core_exit(struct st_data_s *st_gdata)
908{
909 long err;
910 /* internal module cleanup */
911 err = st_ll_deinit(st_gdata);
912 if (err)
913 pr_err("error during deinit of ST LL %ld", err);
914
915 if (st_gdata != NULL) {
916 /* Free ST Tx Qs and skbs */
917 skb_queue_purge(&st_gdata->txq);
918 skb_queue_purge(&st_gdata->tx_waitq);
919 kfree_skb(st_gdata->rx_skb);
920 kfree_skb(st_gdata->tx_skb);
921 /* TTY ldisc cleanup */
922 err = tty_unregister_ldisc(N_TI_WL);
923 if (err)
924 pr_err("unable to un-register ldisc %ld", err);
925 /* free the global data pointer */
926 kfree(st_gdata);
927 }
928}