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 if (st_gdata->list[type] == NULL) { 347 pr_err("chip/interface misbehavior dropping" 348 " frame starting with 0x%02x", type); 349 goto done; 350 351 } 352 st_gdata->rx_skb = alloc_skb( 353 st_gdata->list[type]->max_frame_size, 354 GFP_ATOMIC); 355 if (st_gdata->rx_skb == NULL) { 356 pr_err("out of memory: dropping\n"); 357 goto done; 358 } 359 360 skb_reserve(st_gdata->rx_skb, 361 st_gdata->list[type]->reserve); 362 /* next 2 required for BT only */ 363 st_gdata->rx_skb->cb[0] = type; /*pkt_type*/ 364 st_gdata->rx_skb->cb[1] = 0; /*incoming*/ 365 st_gdata->rx_chnl = *ptr; 366 st_gdata->rx_state = ST_W4_HEADER; 367 st_gdata->rx_count = st_gdata->list[type]->hdr_len; 368 pr_debug("rx_count %ld\n", st_gdata->rx_count); 369 }; 370 ptr++; 371 count--; 372 } 373done: 374 spin_unlock_irqrestore(&st_gdata->lock, flags); 375 pr_debug("done %s", __func__); 376 return; 377} 378 379/** 380 * st_int_dequeue - internal de-Q function. 381 * If the previous data set was not written 382 * completely, return that skb which has the pending data. 383 * In normal cases, return top of txq. 384 */ 385static struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata) 386{ 387 struct sk_buff *returning_skb; 388 389 pr_debug("%s", __func__); 390 if (st_gdata->tx_skb != NULL) { 391 returning_skb = st_gdata->tx_skb; 392 st_gdata->tx_skb = NULL; 393 return returning_skb; 394 } 395 return skb_dequeue(&st_gdata->txq); 396} 397 398/** 399 * st_int_enqueue - internal Q-ing function. 400 * Will either Q the skb to txq or the tx_waitq 401 * depending on the ST LL state. 402 * If the chip is asleep, then Q it onto waitq and 403 * wakeup the chip. 404 * txq and waitq needs protection since the other contexts 405 * may be sending data, waking up chip. 406 */ 407static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb) 408{ 409 unsigned long flags = 0; 410 411 pr_debug("%s", __func__); 412 spin_lock_irqsave(&st_gdata->lock, flags); 413 414 switch (st_ll_getstate(st_gdata)) { 415 case ST_LL_AWAKE: 416 pr_debug("ST LL is AWAKE, sending normally"); 417 skb_queue_tail(&st_gdata->txq, skb); 418 break; 419 case ST_LL_ASLEEP_TO_AWAKE: 420 skb_queue_tail(&st_gdata->tx_waitq, skb); 421 break; 422 case ST_LL_AWAKE_TO_ASLEEP: 423 pr_err("ST LL is illegal state(%ld)," 424 "purging received skb.", st_ll_getstate(st_gdata)); 425 kfree_skb(skb); 426 break; 427 case ST_LL_ASLEEP: 428 skb_queue_tail(&st_gdata->tx_waitq, skb); 429 st_ll_wakeup(st_gdata); 430 break; 431 default: 432 pr_err("ST LL is illegal state(%ld)," 433 "purging received skb.", st_ll_getstate(st_gdata)); 434 kfree_skb(skb); 435 break; 436 } 437 438 spin_unlock_irqrestore(&st_gdata->lock, flags); 439 pr_debug("done %s", __func__); 440 return; 441} 442 443/* 444 * internal wakeup function 445 * called from either 446 * - TTY layer when write's finished 447 * - st_write (in context of the protocol stack) 448 */ 449void st_tx_wakeup(struct st_data_s *st_data) 450{ 451 struct sk_buff *skb; 452 unsigned long flags; /* for irq save flags */ 453 pr_debug("%s", __func__); 454 /* check for sending & set flag sending here */ 455 if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) { 456 pr_debug("ST already sending"); 457 /* keep sending */ 458 set_bit(ST_TX_WAKEUP, &st_data->tx_state); 459 return; 460 /* TX_WAKEUP will be checked in another 461 * context 462 */ 463 } 464 do { /* come back if st_tx_wakeup is set */ 465 /* woke-up to write */ 466 clear_bit(ST_TX_WAKEUP, &st_data->tx_state); 467 while ((skb = st_int_dequeue(st_data))) { 468 int len; 469 spin_lock_irqsave(&st_data->lock, flags); 470 /* enable wake-up from TTY */ 471 set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags); 472 len = st_int_write(st_data, skb->data, skb->len); 473 skb_pull(skb, len); 474 /* if skb->len = len as expected, skb->len=0 */ 475 if (skb->len) { 476 /* would be the next skb to be sent */ 477 st_data->tx_skb = skb; 478 spin_unlock_irqrestore(&st_data->lock, flags); 479 break; 480 } 481 kfree_skb(skb); 482 spin_unlock_irqrestore(&st_data->lock, flags); 483 } 484 /* if wake-up is set in another context- restart sending */ 485 } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state)); 486 487 /* clear flag sending */ 488 clear_bit(ST_TX_SENDING, &st_data->tx_state); 489} 490 491/********************************************************************/ 492/* functions called from ST KIM 493*/ 494void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf) 495{ 496 seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n", 497 st_gdata->protos_registered, 498 st_gdata->is_registered[0x04] == true ? 'R' : 'U', 499 st_gdata->is_registered[0x08] == true ? 'R' : 'U', 500 st_gdata->is_registered[0x09] == true ? 'R' : 'U'); 501} 502 503/********************************************************************/ 504/* 505 * functions called from protocol stack drivers 506 * to be EXPORT-ed 507 */ 508long st_register(struct st_proto_s *new_proto) 509{ 510 struct st_data_s *st_gdata; 511 long err = 0; 512 unsigned long flags = 0; 513 514 st_kim_ref(&st_gdata, 0); 515 if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL 516 || new_proto->reg_complete_cb == NULL) { 517 pr_err("gdata/new_proto/recv or reg_complete_cb not ready"); 518 return -EINVAL; 519 } 520 521 if (new_proto->chnl_id >= ST_MAX_CHANNELS) { 522 pr_err("chnl_id %d not supported", new_proto->chnl_id); 523 return -EPROTONOSUPPORT; 524 } 525 526 if (st_gdata->is_registered[new_proto->chnl_id] == true) { 527 pr_err("chnl_id %d already registered", new_proto->chnl_id); 528 return -EALREADY; 529 } 530 531 /* can be from process context only */ 532 spin_lock_irqsave(&st_gdata->lock, flags); 533 534 if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) { 535 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id); 536 /* fw download in progress */ 537 538 add_channel_to_table(st_gdata, new_proto); 539 st_gdata->protos_registered++; 540 new_proto->write = st_write; 541 542 set_bit(ST_REG_PENDING, &st_gdata->st_state); 543 spin_unlock_irqrestore(&st_gdata->lock, flags); 544 return -EINPROGRESS; 545 } else if (st_gdata->protos_registered == ST_EMPTY) { 546 pr_info(" chnl_id list empty :%d ", new_proto->chnl_id); 547 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state); 548 st_recv = st_kim_recv; 549 550 /* enable the ST LL - to set default chip state */ 551 st_ll_enable(st_gdata); 552 553 /* release lock previously held - re-locked below */ 554 spin_unlock_irqrestore(&st_gdata->lock, flags); 555 556 /* this may take a while to complete 557 * since it involves BT fw download 558 */ 559 err = st_kim_start(st_gdata->kim_data); 560 if (err != 0) { 561 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state); 562 if ((st_gdata->protos_registered != ST_EMPTY) && 563 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) { 564 pr_err(" KIM failure complete callback "); 565 spin_lock_irqsave(&st_gdata->lock, flags); 566 st_reg_complete(st_gdata, err); 567 spin_unlock_irqrestore(&st_gdata->lock, flags); 568 clear_bit(ST_REG_PENDING, &st_gdata->st_state); 569 } 570 return -EINVAL; 571 } 572 573 spin_lock_irqsave(&st_gdata->lock, flags); 574 575 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state); 576 st_recv = st_int_recv; 577 578 /* this is where all pending registration 579 * are signalled to be complete by calling callback functions 580 */ 581 if ((st_gdata->protos_registered != ST_EMPTY) && 582 (test_bit(ST_REG_PENDING, &st_gdata->st_state))) { 583 pr_debug(" call reg complete callback "); 584 st_reg_complete(st_gdata, 0); 585 } 586 clear_bit(ST_REG_PENDING, &st_gdata->st_state); 587 588 /* check for already registered once more, 589 * since the above check is old 590 */ 591 if (st_gdata->is_registered[new_proto->chnl_id] == true) { 592 pr_err(" proto %d already registered ", 593 new_proto->chnl_id); 594 spin_unlock_irqrestore(&st_gdata->lock, flags); 595 return -EALREADY; 596 } 597 598 add_channel_to_table(st_gdata, new_proto); 599 st_gdata->protos_registered++; 600 new_proto->write = st_write; 601 spin_unlock_irqrestore(&st_gdata->lock, flags); 602 return err; 603 } 604 /* if fw is already downloaded & new stack registers protocol */ 605 else { 606 add_channel_to_table(st_gdata, new_proto); 607 st_gdata->protos_registered++; 608 new_proto->write = st_write; 609 610 /* lock already held before entering else */ 611 spin_unlock_irqrestore(&st_gdata->lock, flags); 612 return err; 613 } 614 pr_debug("done %s(%d) ", __func__, new_proto->chnl_id); 615} 616EXPORT_SYMBOL_GPL(st_register); 617 618/* to unregister a protocol - 619 * to be called from protocol stack driver 620 */ 621long st_unregister(struct st_proto_s *proto) 622{ 623 long err = 0; 624 unsigned long flags = 0; 625 struct st_data_s *st_gdata; 626 627 pr_debug("%s: %d ", __func__, proto->chnl_id); 628 629 st_kim_ref(&st_gdata, 0); 630 if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) { 631 pr_err(" chnl_id %d not supported", proto->chnl_id); 632 return -EPROTONOSUPPORT; 633 } 634 635 spin_lock_irqsave(&st_gdata->lock, flags); 636 637 if (st_gdata->is_registered[proto->chnl_id] == false) { 638 pr_err(" chnl_id %d not registered", proto->chnl_id); 639 spin_unlock_irqrestore(&st_gdata->lock, flags); 640 return -EPROTONOSUPPORT; 641 } 642 643 if (st_gdata->protos_registered) 644 st_gdata->protos_registered--; 645 646 remove_channel_from_table(st_gdata, proto); 647 spin_unlock_irqrestore(&st_gdata->lock, flags); 648 649 if ((st_gdata->protos_registered == ST_EMPTY) && 650 (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) { 651 pr_info(" all chnl_ids unregistered "); 652 653 /* stop traffic on tty */ 654 if (st_gdata->tty) { 655 tty_ldisc_flush(st_gdata->tty); 656 stop_tty(st_gdata->tty); 657 } 658 659 /* all chnl_ids now unregistered */ 660 st_kim_stop(st_gdata->kim_data); 661 /* disable ST LL */ 662 st_ll_disable(st_gdata); 663 } 664 return err; 665} 666 667/* 668 * called in protocol stack drivers 669 * via the write function pointer 670 */ 671long st_write(struct sk_buff *skb) 672{ 673 struct st_data_s *st_gdata; 674 long len; 675 676 st_kim_ref(&st_gdata, 0); 677 if (unlikely(skb == NULL || st_gdata == NULL 678 || st_gdata->tty == NULL)) { 679 pr_err("data/tty unavailable to perform write"); 680 return -EINVAL; 681 } 682 683 pr_debug("%d to be written", skb->len); 684 len = skb->len; 685 686 /* st_ll to decide where to enqueue the skb */ 687 st_int_enqueue(st_gdata, skb); 688 /* wake up */ 689 st_tx_wakeup(st_gdata); 690 691 /* return number of bytes written */ 692 return len; 693} 694 695/* for protocols making use of shared transport */ 696EXPORT_SYMBOL_GPL(st_unregister); 697 698/********************************************************************/ 699/* 700 * functions called from TTY layer 701 */ 702static int st_tty_open(struct tty_struct *tty) 703{ 704 int err = 0; 705 struct st_data_s *st_gdata; 706 pr_info("%s ", __func__); 707 708 st_kim_ref(&st_gdata, 0); 709 st_gdata->tty = tty; 710 tty->disc_data = st_gdata; 711 712 /* don't do an wakeup for now */ 713 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 714 715 /* mem already allocated 716 */ 717 tty->receive_room = 65536; 718 /* Flush any pending characters in the driver and discipline. */ 719 tty_ldisc_flush(tty); 720 tty_driver_flush_buffer(tty); 721 /* 722 * signal to UIM via KIM that - 723 * installation of N_TI_WL ldisc is complete 724 */ 725 st_kim_complete(st_gdata->kim_data); 726 pr_debug("done %s", __func__); 727 return err; 728} 729 730static void st_tty_close(struct tty_struct *tty) 731{ 732 unsigned char i = ST_MAX_CHANNELS; 733 unsigned long flags = 0; 734 struct st_data_s *st_gdata = tty->disc_data; 735 736 pr_info("%s ", __func__); 737 738 /* TODO: 739 * if a protocol has been registered & line discipline 740 * un-installed for some reason - what should be done ? 741 */ 742 spin_lock_irqsave(&st_gdata->lock, flags); 743 for (i = ST_BT; i < ST_MAX_CHANNELS; i++) { 744 if (st_gdata->is_registered[i] == true) 745 pr_err("%d not un-registered", i); 746 st_gdata->list[i] = NULL; 747 st_gdata->is_registered[i] = false; 748 } 749 st_gdata->protos_registered = 0; 750 spin_unlock_irqrestore(&st_gdata->lock, flags); 751 /* 752 * signal to UIM via KIM that - 753 * N_TI_WL ldisc is un-installed 754 */ 755 st_kim_complete(st_gdata->kim_data); 756 st_gdata->tty = NULL; 757 /* Flush any pending characters in the driver and discipline. */ 758 tty_ldisc_flush(tty); 759 tty_driver_flush_buffer(tty); 760 761 spin_lock_irqsave(&st_gdata->lock, flags); 762 /* empty out txq and tx_waitq */ 763 skb_queue_purge(&st_gdata->txq); 764 skb_queue_purge(&st_gdata->tx_waitq); 765 /* reset the TTY Rx states of ST */ 766 st_gdata->rx_count = 0; 767 st_gdata->rx_state = ST_W4_PACKET_TYPE; 768 kfree_skb(st_gdata->rx_skb); 769 st_gdata->rx_skb = NULL; 770 spin_unlock_irqrestore(&st_gdata->lock, flags); 771 772 pr_debug("%s: done ", __func__); 773} 774 775static void st_tty_receive(struct tty_struct *tty, const unsigned char *data, 776 char *tty_flags, int count) 777{ 778#ifdef VERBOSE 779 print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE, 780 16, 1, data, count, 0); 781#endif 782 783 /* 784 * if fw download is in progress then route incoming data 785 * to KIM for validation 786 */ 787 st_recv(tty->disc_data, data, count); 788 pr_debug("done %s", __func__); 789} 790 791/* wake-up function called in from the TTY layer 792 * inside the internal wakeup function will be called 793 */ 794static void st_tty_wakeup(struct tty_struct *tty) 795{ 796 struct st_data_s *st_gdata = tty->disc_data; 797 pr_debug("%s ", __func__); 798 /* don't do an wakeup for now */ 799 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 800 801 /* call our internal wakeup */ 802 st_tx_wakeup((void *)st_gdata); 803} 804 805static void st_tty_flush_buffer(struct tty_struct *tty) 806{ 807 struct st_data_s *st_gdata = tty->disc_data; 808 pr_debug("%s ", __func__); 809 810 kfree_skb(st_gdata->tx_skb); 811 st_gdata->tx_skb = NULL; 812 813 tty_driver_flush_buffer(tty); 814 return; 815} 816 817static struct tty_ldisc_ops st_ldisc_ops = { 818 .magic = TTY_LDISC_MAGIC, 819 .name = "n_st", 820 .open = st_tty_open, 821 .close = st_tty_close, 822 .receive_buf = st_tty_receive, 823 .write_wakeup = st_tty_wakeup, 824 .flush_buffer = st_tty_flush_buffer, 825 .owner = THIS_MODULE 826}; 827 828/********************************************************************/ 829int st_core_init(struct st_data_s **core_data) 830{ 831 struct st_data_s *st_gdata; 832 long err; 833 834 err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops); 835 if (err) { 836 pr_err("error registering %d line discipline %ld", 837 N_TI_WL, err); 838 return err; 839 } 840 pr_debug("registered n_shared line discipline"); 841 842 st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL); 843 if (!st_gdata) { 844 pr_err("memory allocation failed"); 845 err = tty_unregister_ldisc(N_TI_WL); 846 if (err) 847 pr_err("unable to un-register ldisc %ld", err); 848 err = -ENOMEM; 849 return err; 850 } 851 852 /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's 853 * will be pushed in this queue for actual transmission. 854 */ 855 skb_queue_head_init(&st_gdata->txq); 856 skb_queue_head_init(&st_gdata->tx_waitq); 857 858 /* Locking used in st_int_enqueue() to avoid multiple execution */ 859 spin_lock_init(&st_gdata->lock); 860 861 err = st_ll_init(st_gdata); 862 if (err) { 863 pr_err("error during st_ll initialization(%ld)", err); 864 kfree(st_gdata); 865 err = tty_unregister_ldisc(N_TI_WL); 866 if (err) 867 pr_err("unable to un-register ldisc"); 868 return err; 869 } 870 *core_data = st_gdata; 871 return 0; 872} 873 874void st_core_exit(struct st_data_s *st_gdata) 875{ 876 long err; 877 /* internal module cleanup */ 878 err = st_ll_deinit(st_gdata); 879 if (err) 880 pr_err("error during deinit of ST LL %ld", err); 881 882 if (st_gdata != NULL) { 883 /* Free ST Tx Qs and skbs */ 884 skb_queue_purge(&st_gdata->txq); 885 skb_queue_purge(&st_gdata->tx_waitq); 886 kfree_skb(st_gdata->rx_skb); 887 kfree_skb(st_gdata->tx_skb); 888 /* TTY ldisc cleanup */ 889 err = tty_unregister_ldisc(N_TI_WL); 890 if (err) 891 pr_err("unable to un-register ldisc %ld", err); 892 /* free the global data pointer */ 893 kfree(st_gdata); 894 } 895} 896 897 898