drivers/misc/ti-st/st_core.c

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