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 <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 /* understand BT, FM and GPS for now */
  29 #include <net/bluetooth/bluetooth.h>
  30 #include <net/bluetooth/hci_core.h>
  31 #include <net/bluetooth/hci.h>
  32 #include <linux/ti_wilink_st.h>
  33
  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 void (*st_recv) (void*, const unsigned char*, long);
  39
  40 /********************************************************************/
  41 #if 0
  42 /* internal misc functions */
  43 bool is_protocol_list_empty(void)
  44 {
  45         unsigned char i = 0;
  46         pr_debug(" %s ", __func__);
  47         for (i = 0; i < ST_MAX; i++) {
  48                 if (st_gdata->list[i] != NULL)
  49                         return ST_NOTEMPTY;
  50                 /* not empty */
  51         }
  52         /* list empty */
  53         return ST_EMPTY;
  54 }
  55 #endif
  56
  57 /* can be called in from
  58  * -- KIM (during fw download)
  59  * -- ST Core (during st_write)
  60  *
  61  *  This is the internal write function - a wrapper
  62  *  to tty->ops->write
  63  */
  64 int st_int_write(struct st_data_s *st_gdata,
  65         const unsigned char *data, int count)
  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 #ifdef VERBOSE
  74         print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
  75                 16, 1, data, count, 0);
  76 #endif
  77         return tty->ops->write(tty, data, count);
  78
  79 }
  80
  81 /*
  82  * push the skb received to relevant
  83  * protocol stacks
  84  */
  85 void st_send_frame(enum proto_type protoid, struct st_data_s *st_gdata)
  86 {
  87         pr_info(" %s(prot:%d) ", __func__, protoid);
  88
  89         if (unlikely
  90             (st_gdata == NULL || st_gdata->rx_skb == NULL
  91              || st_gdata->list[protoid] == NULL)) {
  92                 pr_err("protocol %d not registered, no data to send?",
  93                            protoid);
  94                 kfree_skb(st_gdata->rx_skb);
  95                 return;
  96         }
  97         /* this cannot fail
  98          * this shouldn't take long
  99          * - should be just skb_queue_tail for the
 100          *   protocol stack driver
 101          */
 102         if (likely(st_gdata->list[protoid]->recv != NULL)) {
 103                 if (unlikely
 104                         (st_gdata->list[protoid]->recv
 105                         (st_gdata->list[protoid]->priv_data, st_gdata->rx_skb)
 106                              != 0)) {
 107                         pr_err(" proto stack %d's ->recv failed", protoid);
 108                         kfree_skb(st_gdata->rx_skb);
 109                         return;
 110                 }
 111         } else {
 112                 pr_err(" proto stack %d's ->recv null", protoid);
 113                 kfree_skb(st_gdata->rx_skb);
 114         }
 115         return;
 116 }
 117
 118 /**
 119  * st_reg_complete -
 120  * to call registration complete callbacks
 121  * of all protocol stack drivers
 122  */
 123 void st_reg_complete(struct st_data_s *st_gdata, char err)
 124 {
 125         unsigned char i = 0;
 126         pr_info(" %s ", __func__);
 127         for (i = 0; i < ST_MAX; i++) {
 128                 if (likely(st_gdata != NULL && st_gdata->list[i] != NULL &&
 129                            st_gdata->list[i]->reg_complete_cb != NULL))
 130                         st_gdata->list[i]->reg_complete_cb
 131                                 (st_gdata->list[i]->priv_data, err);
 132         }
 133 }
 134
 135 static inline int st_check_data_len(struct st_data_s *st_gdata,
 136         int protoid, int len)
 137 {
 138         int room = skb_tailroom(st_gdata->rx_skb);
 139
 140         pr_debug("len %d room %d", len, room);
 141
 142         if (!len) {
 143                 /* Received packet has only packet header and
 144                  * has zero length payload. So, ask ST CORE to
 145                  * forward the packet to protocol driver (BT/FM/GPS)
 146                  */
 147                 st_send_frame(protoid, st_gdata);
 148
 149         } else if (len > room) {
 150                 /* Received packet's payload length is larger.
 151                  * We can't accommodate it in created skb.
 152                  */
 153                 pr_err("Data length is too large len %d room %d", len,
 154                            room);
 155                 kfree_skb(st_gdata->rx_skb);
 156         } else {
 157                 /* Packet header has non-zero payload length and
 158                  * we have enough space in created skb. Lets read
 159                  * payload data */
 160                 st_gdata->rx_state = ST_BT_W4_DATA;
 161                 st_gdata->rx_count = len;
 162                 return len;
 163         }
 164
 165         /* Change ST state to continue to process next
 166          * packet */
 167         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 168         st_gdata->rx_skb = NULL;
 169         st_gdata->rx_count = 0;
 170
 171         return 0;
 172 }
 173
 174 /**
 175  * st_wakeup_ack - internal function for action when wake-up ack
 176  *      received
 177  */
 178 static inline void st_wakeup_ack(struct st_data_s *st_gdata,
 179         unsigned char cmd)
 180 {
 181         struct sk_buff *waiting_skb;
 182         unsigned long flags = 0;
 183
 184         spin_lock_irqsave(&st_gdata->lock, flags);
 185         /* de-Q from waitQ and Q in txQ now that the
 186          * chip is awake
 187          */
 188         while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
 189                 skb_queue_tail(&st_gdata->txq, waiting_skb);
 190
 191         /* state forwarded to ST LL */
 192         st_ll_sleep_state(st_gdata, (unsigned long)cmd);
 193         spin_unlock_irqrestore(&st_gdata->lock, flags);
 194
 195         /* wake up to send the recently copied skbs from waitQ */
 196         st_tx_wakeup(st_gdata);
 197 }
 198
 199 /**
 200  * st_int_recv - ST's internal receive function.
 201  *      Decodes received RAW data and forwards to corresponding
 202  *      client drivers (Bluetooth,FM,GPS..etc).
 203  *      This can receive various types of packets,
 204  *      HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
 205  *      CH-8 packets from FM, CH-9 packets from GPS cores.
 206  */
 207 void st_int_recv(void *disc_data,
 208         const unsigned char *data, long count)
 209 {
 210         char *ptr;
 211         struct hci_event_hdr *eh;
 212         struct hci_acl_hdr *ah;
 213         struct hci_sco_hdr *sh;
 214         struct fm_event_hdr *fm;
 215         struct gps_event_hdr *gps;
 216         int len = 0, type = 0, dlen = 0;
 217         static enum proto_type protoid = ST_MAX;
 218         struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
 219
 220         ptr = (char *)data;
 221         /* tty_receive sent null ? */
 222         if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
 223                 pr_err(" received null from TTY ");
 224                 return;
 225         }
 226
 227         pr_info("count %ld rx_state %ld"
 228                    "rx_count %ld", count, st_gdata->rx_state,
 229                    st_gdata->rx_count);
 230
 231         /* Decode received bytes here */
 232         while (count) {
 233                 if (st_gdata->rx_count) {
 234                         len = min_t(unsigned int, st_gdata->rx_count, count);
 235                         memcpy(skb_put(st_gdata->rx_skb, len), ptr, len);
 236                         st_gdata->rx_count -= len;
 237                         count -= len;
 238                         ptr += len;
 239
 240                         if (st_gdata->rx_count)
 241                                 continue;
 242
 243                         /* Check ST RX state machine , where are we? */
 244                         switch (st_gdata->rx_state) {
 245
 246                                 /* Waiting for complete packet ? */
 247                         case ST_BT_W4_DATA:
 248                                 pr_debug("Complete pkt received");
 249
 250                                 /* Ask ST CORE to forward
 251                                  * the packet to protocol driver */
 252                                 st_send_frame(protoid, st_gdata);
 253
 254                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 255                                 st_gdata->rx_skb = NULL;
 256                                 protoid = ST_MAX;       /* is this required ? */
 257                                 continue;
 258
 259                                 /* Waiting for Bluetooth event header ? */
 260                         case ST_BT_W4_EVENT_HDR:
 261                                 eh = (struct hci_event_hdr *)st_gdata->rx_skb->
 262                                     data;
 263
 264                                 pr_debug("Event header: evt 0x%2.2x"
 265                                            "plen %d", eh->evt, eh->plen);
 266
 267                                 st_check_data_len(st_gdata, protoid, eh->plen);
 268                                 continue;
 269
 270                                 /* Waiting for Bluetooth acl header ? */
 271                         case ST_BT_W4_ACL_HDR:
 272                                 ah = (struct hci_acl_hdr *)st_gdata->rx_skb->
 273                                     data;
 274                                 dlen = __le16_to_cpu(ah->dlen);
 275
 276                                 pr_info("ACL header: dlen %d", dlen);
 277
 278                                 st_check_data_len(st_gdata, protoid, dlen);
 279                                 continue;
 280
 281                                 /* Waiting for Bluetooth sco header ? */
 282                         case ST_BT_W4_SCO_HDR:
 283                                 sh = (struct hci_sco_hdr *)st_gdata->rx_skb->
 284                                     data;
 285
 286                                 pr_info("SCO header: dlen %d", sh->dlen);
 287
 288                                 st_check_data_len(st_gdata, protoid, sh->dlen);
 289                                 continue;
 290                         case ST_FM_W4_EVENT_HDR:
 291                                 fm = (struct fm_event_hdr *)st_gdata->rx_skb->
 292                                     data;
 293                                 pr_info("FM Header: ");
 294                                 st_check_data_len(st_gdata, ST_FM, fm->plen);
 295                                 continue;
 296                                 /* TODO : Add GPS packet machine logic here */
 297                         case ST_GPS_W4_EVENT_HDR:
 298                                 /* [0x09 pkt hdr][R/W byte][2 byte len] */
 299                                 gps = (struct gps_event_hdr *)st_gdata->rx_skb->
 300                                      data;
 301                                 pr_info("GPS Header: ");
 302                                 st_check_data_len(st_gdata, ST_GPS, gps->plen);
 303                                 continue;
 304                         }       /* end of switch rx_state */
 305                 }
 306
 307                 /* end of if rx_count */
 308                 /* Check first byte of packet and identify module
 309                  * owner (BT/FM/GPS) */
 310                 switch (*ptr) {
 311
 312                         /* Bluetooth event packet? */
 313                 case HCI_EVENT_PKT:
 314                         pr_info("Event packet");
 315                         st_gdata->rx_state = ST_BT_W4_EVENT_HDR;
 316                         st_gdata->rx_count = HCI_EVENT_HDR_SIZE;
 317                         type = HCI_EVENT_PKT;
 318                         protoid = ST_BT;
 319                         break;
 320
 321                         /* Bluetooth acl packet? */
 322                 case HCI_ACLDATA_PKT:
 323                         pr_info("ACL packet");
 324                         st_gdata->rx_state = ST_BT_W4_ACL_HDR;
 325                         st_gdata->rx_count = HCI_ACL_HDR_SIZE;
 326                         type = HCI_ACLDATA_PKT;
 327                         protoid = ST_BT;
 328                         break;
 329
 330                         /* Bluetooth sco packet? */
 331                 case HCI_SCODATA_PKT:
 332                         pr_info("SCO packet");
 333                         st_gdata->rx_state = ST_BT_W4_SCO_HDR;
 334                         st_gdata->rx_count = HCI_SCO_HDR_SIZE;
 335                         type = HCI_SCODATA_PKT;
 336                         protoid = ST_BT;
 337                         break;
 338
 339                         /* Channel 8(FM) packet? */
 340                 case ST_FM_CH8_PKT:
 341                         pr_info("FM CH8 packet");
 342                         type = ST_FM_CH8_PKT;
 343                         st_gdata->rx_state = ST_FM_W4_EVENT_HDR;
 344                         st_gdata->rx_count = FM_EVENT_HDR_SIZE;
 345                         protoid = ST_FM;
 346                         break;
 347
 348                         /* Channel 9(GPS) packet? */
 349                 case 0x9:       /*ST_LL_GPS_CH9_PKT */
 350                         pr_info("GPS CH9 packet");
 351                         type = 0x9;     /* ST_LL_GPS_CH9_PKT; */
 352                         protoid = ST_GPS;
 353                         st_gdata->rx_state = ST_GPS_W4_EVENT_HDR;
 354                         st_gdata->rx_count = 3; /* GPS_EVENT_HDR_SIZE -1*/
 355                         break;
 356                 case LL_SLEEP_IND:
 357                 case LL_SLEEP_ACK:
 358                 case LL_WAKE_UP_IND:
 359                         pr_info("PM packet");
 360                         /* this takes appropriate action based on
 361                          * sleep state received --
 362                          */
 363                         st_ll_sleep_state(st_gdata, *ptr);
 364                         ptr++;
 365                         count--;
 366                         continue;
 367                 case LL_WAKE_UP_ACK:
 368                         pr_info("PM packet");
 369                         /* wake up ack received */
 370                         st_wakeup_ack(st_gdata, *ptr);
 371                         ptr++;
 372                         count--;
 373                         continue;
 374                         /* Unknow packet? */
 375                 default:
 376                         pr_err("Unknown packet type %2.2x", (__u8) *ptr);
 377                         ptr++;
 378                         count--;
 379                         continue;
 380                 };
 381                 ptr++;
 382                 count--;
 383
 384                 switch (protoid) {
 385                 case ST_BT:
 386                         /* Allocate new packet to hold received data */
 387                         st_gdata->rx_skb =
 388                             bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 389                         if (!st_gdata->rx_skb) {
 390                                 pr_err("Can't allocate mem for new packet");
 391                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 392                                 st_gdata->rx_count = 0;
 393                                 return;
 394                         }
 395                         bt_cb(st_gdata->rx_skb)->pkt_type = type;
 396                         break;
 397                 case ST_FM:     /* for FM */
 398                         st_gdata->rx_skb =
 399                             alloc_skb(FM_MAX_FRAME_SIZE, GFP_ATOMIC);
 400                         if (!st_gdata->rx_skb) {
 401                                 pr_err("Can't allocate mem for new packet");
 402                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 403                                 st_gdata->rx_count = 0;
 404                                 return;
 405                         }
 406                         /* place holder 0x08 */
 407                         skb_reserve(st_gdata->rx_skb, 1);
 408                         st_gdata->rx_skb->cb[0] = ST_FM_CH8_PKT;
 409                         break;
 410                 case ST_GPS:
 411                         /* for GPS */
 412                         st_gdata->rx_skb =
 413                             alloc_skb(100 /*GPS_MAX_FRAME_SIZE */ , GFP_ATOMIC);
 414                         if (!st_gdata->rx_skb) {
 415                                 pr_err("Can't allocate mem for new packet");
 416                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 417                                 st_gdata->rx_count = 0;
 418                                 return;
 419                         }
 420                         /* place holder 0x09 */
 421                         skb_reserve(st_gdata->rx_skb, 1);
 422                         st_gdata->rx_skb->cb[0] = 0x09; /*ST_GPS_CH9_PKT; */
 423                         break;
 424                 case ST_MAX:
 425                         break;
 426                 }
 427         }
 428         pr_debug("done %s", __func__);
 429         return;
 430 }
 431
 432 /**
 433  * st_int_dequeue - internal de-Q function.
 434  *      If the previous data set was not written
 435  *      completely, return that skb which has the pending data.
 436  *      In normal cases, return top of txq.
 437  */
 438 struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
 439 {
 440         struct sk_buff *returning_skb;
 441
 442         pr_debug("%s", __func__);
 443         if (st_gdata->tx_skb != NULL) {
 444                 returning_skb = st_gdata->tx_skb;
 445                 st_gdata->tx_skb = NULL;
 446                 return returning_skb;
 447         }
 448         return skb_dequeue(&st_gdata->txq);
 449 }
 450
 451 /**
 452  * st_int_enqueue - internal Q-ing function.
 453  *      Will either Q the skb to txq or the tx_waitq
 454  *      depending on the ST LL state.
 455  *      If the chip is asleep, then Q it onto waitq and
 456  *      wakeup the chip.
 457  *      txq and waitq needs protection since the other contexts
 458  *      may be sending data, waking up chip.
 459  */
 460 void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
 461 {
 462         unsigned long flags = 0;
 463
 464         pr_debug("%s", __func__);
 465         spin_lock_irqsave(&st_gdata->lock, flags);
 466
 467         switch (st_ll_getstate(st_gdata)) {
 468         case ST_LL_AWAKE:
 469                 pr_info("ST LL is AWAKE, sending normally");
 470                 skb_queue_tail(&st_gdata->txq, skb);
 471                 break;
 472         case ST_LL_ASLEEP_TO_AWAKE:
 473                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 474                 break;
 475         case ST_LL_AWAKE_TO_ASLEEP:
 476                 pr_err("ST LL is illegal state(%ld),"
 477                            "purging received skb.", st_ll_getstate(st_gdata));
 478                 kfree_skb(skb);
 479                 break;
 480         case ST_LL_ASLEEP:
 481                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 482                 st_ll_wakeup(st_gdata);
 483                 break;
 484         default:
 485                 pr_err("ST LL is illegal state(%ld),"
 486                            "purging received skb.", st_ll_getstate(st_gdata));
 487                 kfree_skb(skb);
 488                 break;
 489         }
 490
 491         spin_unlock_irqrestore(&st_gdata->lock, flags);
 492         pr_debug("done %s", __func__);
 493         return;
 494 }
 495
 496 /*
 497  * internal wakeup function
 498  * called from either
 499  * - TTY layer when write's finished
 500  * - st_write (in context of the protocol stack)
 501  */
 502 void st_tx_wakeup(struct st_data_s *st_data)
 503 {
 504         struct sk_buff *skb;
 505         unsigned long flags;    /* for irq save flags */
 506         pr_debug("%s", __func__);
 507         /* check for sending & set flag sending here */
 508         if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
 509                 pr_info("ST already sending");
 510                 /* keep sending */
 511                 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
 512                 return;
 513                 /* TX_WAKEUP will be checked in another
 514                  * context
 515                  */
 516         }
 517         do {                    /* come back if st_tx_wakeup is set */
 518                 /* woke-up to write */
 519                 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
 520                 while ((skb = st_int_dequeue(st_data))) {
 521                         int len;
 522                         spin_lock_irqsave(&st_data->lock, flags);
 523                         /* enable wake-up from TTY */
 524                         set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
 525                         len = st_int_write(st_data, skb->data, skb->len);
 526                         skb_pull(skb, len);
 527                         /* if skb->len = len as expected, skb->len=0 */
 528                         if (skb->len) {
 529                                 /* would be the next skb to be sent */
 530                                 st_data->tx_skb = skb;
 531                                 spin_unlock_irqrestore(&st_data->lock, flags);
 532                                 break;
 533                         }
 534                         kfree_skb(skb);
 535                         spin_unlock_irqrestore(&st_data->lock, flags);
 536                 }
 537                 /* if wake-up is set in another context- restart sending */
 538         } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
 539
 540         /* clear flag sending */
 541         clear_bit(ST_TX_SENDING, &st_data->tx_state);
 542 }
 543
 544 /********************************************************************/
 545 /* functions called from ST KIM
 546 */
 547 void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
 548 {
 549         seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
 550                         st_gdata->protos_registered,
 551                         st_gdata->list[ST_BT] != NULL ? 'R' : 'U',
 552                         st_gdata->list[ST_FM] != NULL ? 'R' : 'U',
 553                         st_gdata->list[ST_GPS] != NULL ? 'R' : 'U');
 554 }
 555
 556 /********************************************************************/
 557 /*
 558  * functions called from protocol stack drivers
 559  * to be EXPORT-ed
 560  */
 561 long st_register(struct st_proto_s *new_proto)
 562 {
 563         struct st_data_s        *st_gdata;
 564         long err = 0;
 565         unsigned long flags = 0;
 566
 567         st_kim_ref(&st_gdata, 0);
 568         pr_info("%s(%d) ", __func__, new_proto->type);
 569         if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
 570             || new_proto->reg_complete_cb == NULL) {
 571                 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
 572                 return -1;
 573         }
 574
 575         if (new_proto->type < ST_BT || new_proto->type >= ST_MAX) {
 576                 pr_err("protocol %d not supported", new_proto->type);
 577                 return -EPROTONOSUPPORT;
 578         }
 579
 580         if (st_gdata->list[new_proto->type] != NULL) {
 581                 pr_err("protocol %d already registered", new_proto->type);
 582                 return -EALREADY;
 583         }
 584
 585         /* can be from process context only */
 586         spin_lock_irqsave(&st_gdata->lock, flags);
 587
 588         if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
 589                 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->type);
 590                 /* fw download in progress */
 591                 st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 592
 593                 st_gdata->list[new_proto->type] = new_proto;
 594                 st_gdata->protos_registered++;
 595                 new_proto->write = st_write;
 596
 597                 set_bit(ST_REG_PENDING, &st_gdata->st_state);
 598                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 599                 return -EINPROGRESS;
 600         } else if (st_gdata->protos_registered == ST_EMPTY) {
 601                 pr_info(" protocol list empty :%d ", new_proto->type);
 602                 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 603                 st_recv = st_kim_recv;
 604
 605                 /* release lock previously held - re-locked below */
 606                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 607
 608                 /* enable the ST LL - to set default chip state */
 609                 st_ll_enable(st_gdata);
 610                 /* this may take a while to complete
 611                  * since it involves BT fw download
 612                  */
 613                 err = st_kim_start(st_gdata->kim_data);
 614                 if (err != 0) {
 615                         clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 616                         if ((st_gdata->protos_registered != ST_EMPTY) &&
 617                             (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 618                                 pr_err(" KIM failure complete callback ");
 619                                 st_reg_complete(st_gdata, -1);
 620                         }
 621
 622                         return -1;
 623                 }
 624
 625                 /* the protocol might require other gpios to be toggled
 626                  */
 627                 st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 628
 629                 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 630                 st_recv = st_int_recv;
 631
 632                 /* this is where all pending registration
 633                  * are signalled to be complete by calling callback functions
 634                  */
 635                 if ((st_gdata->protos_registered != ST_EMPTY) &&
 636                     (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 637                         pr_debug(" call reg complete callback ");
 638                         st_reg_complete(st_gdata, 0);
 639                 }
 640                 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
 641
 642                 /* check for already registered once more,
 643                  * since the above check is old
 644                  */
 645                 if (st_gdata->list[new_proto->type] != NULL) {
 646                         pr_err(" proto %d already registered ",
 647                                    new_proto->type);
 648                         return -EALREADY;
 649                 }
 650
 651                 spin_lock_irqsave(&st_gdata->lock, flags);
 652                 st_gdata->list[new_proto->type] = new_proto;
 653                 st_gdata->protos_registered++;
 654                 new_proto->write = st_write;
 655                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 656                 return err;
 657         }
 658         /* if fw is already downloaded & new stack registers protocol */
 659         else {
 660                 switch (new_proto->type) {
 661                 case ST_BT:
 662                         /* do nothing */
 663                         break;
 664                 case ST_FM:
 665                 case ST_GPS:
 666                         st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 667                         break;
 668                 case ST_MAX:
 669                 default:
 670                         pr_err("%d protocol not supported",
 671                                    new_proto->type);
 672                         spin_unlock_irqrestore(&st_gdata->lock, flags);
 673                         return -EPROTONOSUPPORT;
 674                 }
 675                 st_gdata->list[new_proto->type] = new_proto;
 676                 st_gdata->protos_registered++;
 677                 new_proto->write = st_write;
 678
 679                 /* lock already held before entering else */
 680                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 681                 return err;
 682         }
 683         pr_debug("done %s(%d) ", __func__, new_proto->type);
 684 }
 685 EXPORT_SYMBOL_GPL(st_register);
 686
 687 /* to unregister a protocol -
 688  * to be called from protocol stack driver
 689  */
 690 long st_unregister(enum proto_type type)
 691 {
 692         long err = 0;
 693         unsigned long flags = 0;
 694         struct st_data_s        *st_gdata;
 695
 696         pr_debug("%s: %d ", __func__, type);
 697
 698         st_kim_ref(&st_gdata, 0);
 699         if (type < ST_BT || type >= ST_MAX) {
 700                 pr_err(" protocol %d not supported", type);
 701                 return -EPROTONOSUPPORT;
 702         }
 703
 704         spin_lock_irqsave(&st_gdata->lock, flags);
 705
 706         if (st_gdata->list[type] == NULL) {
 707                 pr_err(" protocol %d not registered", type);
 708                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 709                 return -EPROTONOSUPPORT;
 710         }
 711
 712         st_gdata->protos_registered--;
 713         st_gdata->list[type] = NULL;
 714
 715         /* kim ignores BT in the below function
 716          * and handles the rest, BT is toggled
 717          * only in kim_start and kim_stop
 718          */
 719         st_kim_chip_toggle(type, KIM_GPIO_INACTIVE);
 720         spin_unlock_irqrestore(&st_gdata->lock, flags);
 721
 722         if ((st_gdata->protos_registered == ST_EMPTY) &&
 723             (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 724                 pr_info(" all protocols unregistered ");
 725
 726                 /* stop traffic on tty */
 727                 if (st_gdata->tty) {
 728                         tty_ldisc_flush(st_gdata->tty);
 729                         stop_tty(st_gdata->tty);
 730                 }
 731
 732                 /* all protocols now unregistered */
 733                 st_kim_stop(st_gdata->kim_data);
 734                 /* disable ST LL */
 735                 st_ll_disable(st_gdata);
 736         }
 737         return err;
 738 }
 739
 740 /*
 741  * called in protocol stack drivers
 742  * via the write function pointer
 743  */
 744 long st_write(struct sk_buff *skb)
 745 {
 746         struct st_data_s *st_gdata;
 747 #ifdef DEBUG
 748         enum proto_type protoid = ST_MAX;
 749 #endif
 750         long len;
 751
 752         st_kim_ref(&st_gdata, 0);
 753         if (unlikely(skb == NULL || st_gdata == NULL
 754                 || st_gdata->tty == NULL)) {
 755                 pr_err("data/tty unavailable to perform write");
 756                 return -1;
 757         }
 758 #ifdef DEBUG                    /* open-up skb to read the 1st byte */
 759         switch (skb->data[0]) {
 760         case HCI_COMMAND_PKT:
 761         case HCI_ACLDATA_PKT:
 762         case HCI_SCODATA_PKT:
 763                 protoid = ST_BT;
 764                 break;
 765         case ST_FM_CH8_PKT:
 766                 protoid = ST_FM;
 767                 break;
 768         case 0x09:
 769                 protoid = ST_GPS;
 770                 break;
 771         }
 772         if (unlikely(st_gdata->list[protoid] == NULL)) {
 773                 pr_err(" protocol %d not registered, and writing? ",
 774                            protoid);
 775                 return -1;
 776         }
 777 #endif
 778         pr_debug("%d to be written", skb->len);
 779         len = skb->len;
 780
 781         /* st_ll to decide where to enqueue the skb */
 782         st_int_enqueue(st_gdata, skb);
 783         /* wake up */
 784         st_tx_wakeup(st_gdata);
 785
 786         /* return number of bytes written */
 787         return len;
 788 }
 789
 790 /* for protocols making use of shared transport */
 791 EXPORT_SYMBOL_GPL(st_unregister);
 792
 793 /********************************************************************/
 794 /*
 795  * functions called from TTY layer
 796  */
 797 static int st_tty_open(struct tty_struct *tty)
 798 {
 799         int err = 0;
 800         struct st_data_s *st_gdata;
 801         pr_info("%s ", __func__);
 802
 803         st_kim_ref(&st_gdata, 0);
 804         st_gdata->tty = tty;
 805         tty->disc_data = st_gdata;
 806
 807         /* don't do an wakeup for now */
 808         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 809
 810         /* mem already allocated
 811          */
 812         tty->receive_room = 65536;
 813         /* Flush any pending characters in the driver and discipline. */
 814         tty_ldisc_flush(tty);
 815         tty_driver_flush_buffer(tty);
 816         /*
 817          * signal to UIM via KIM that -
 818          * installation of N_TI_WL ldisc is complete
 819          */
 820         st_kim_complete(st_gdata->kim_data);
 821         pr_debug("done %s", __func__);
 822         return err;
 823 }
 824
 825 static void st_tty_close(struct tty_struct *tty)
 826 {
 827         unsigned char i = ST_MAX;
 828         unsigned long flags = 0;
 829         struct  st_data_s *st_gdata = tty->disc_data;
 830
 831         pr_info("%s ", __func__);
 832
 833         /* TODO:
 834          * if a protocol has been registered & line discipline
 835          * un-installed for some reason - what should be done ?
 836          */
 837         spin_lock_irqsave(&st_gdata->lock, flags);
 838         for (i = ST_BT; i < ST_MAX; i++) {
 839                 if (st_gdata->list[i] != NULL)
 840                         pr_err("%d not un-registered", i);
 841                 st_gdata->list[i] = NULL;
 842         }
 843         st_gdata->protos_registered = 0;
 844         spin_unlock_irqrestore(&st_gdata->lock, flags);
 845         /*
 846          * signal to UIM via KIM that -
 847          * N_TI_WL ldisc is un-installed
 848          */
 849         st_kim_complete(st_gdata->kim_data);
 850         st_gdata->tty = NULL;
 851         /* Flush any pending characters in the driver and discipline. */
 852         tty_ldisc_flush(tty);
 853         tty_driver_flush_buffer(tty);
 854
 855         spin_lock_irqsave(&st_gdata->lock, flags);
 856         /* empty out txq and tx_waitq */
 857         skb_queue_purge(&st_gdata->txq);
 858         skb_queue_purge(&st_gdata->tx_waitq);
 859         /* reset the TTY Rx states of ST */
 860         st_gdata->rx_count = 0;
 861         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 862         kfree_skb(st_gdata->rx_skb);
 863         st_gdata->rx_skb = NULL;
 864         spin_unlock_irqrestore(&st_gdata->lock, flags);
 865
 866         pr_debug("%s: done ", __func__);
 867 }
 868
 869 static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
 870                            char *tty_flags, int count)
 871 {
 872
 873 #ifdef VERBOSE
 874         print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
 875                 16, 1, data, count, 0);
 876 #endif
 877
 878         /*
 879          * if fw download is in progress then route incoming data
 880          * to KIM for validation
 881          */
 882         st_recv(tty->disc_data, data, count);
 883         pr_debug("done %s", __func__);
 884 }
 885
 886 /* wake-up function called in from the TTY layer
 887  * inside the internal wakeup function will be called
 888  */
 889 static void st_tty_wakeup(struct tty_struct *tty)
 890 {
 891         struct  st_data_s *st_gdata = tty->disc_data;
 892         pr_debug("%s ", __func__);
 893         /* don't do an wakeup for now */
 894         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 895
 896         /* call our internal wakeup */
 897         st_tx_wakeup((void *)st_gdata);
 898 }
 899
 900 static void st_tty_flush_buffer(struct tty_struct *tty)
 901 {
 902         struct  st_data_s *st_gdata = tty->disc_data;
 903         pr_debug("%s ", __func__);
 904
 905         kfree_skb(st_gdata->tx_skb);
 906         st_gdata->tx_skb = NULL;
 907
 908         tty->ops->flush_buffer(tty);
 909         return;
 910 }
 911
 912 static struct tty_ldisc_ops st_ldisc_ops = {
 913         .magic = TTY_LDISC_MAGIC,
 914         .name = "n_st",
 915         .open = st_tty_open,
 916         .close = st_tty_close,
 917         .receive_buf = st_tty_receive,
 918         .write_wakeup = st_tty_wakeup,
 919         .flush_buffer = st_tty_flush_buffer,
 920         .owner = THIS_MODULE
 921 };
 922
 923 /********************************************************************/
 924 int st_core_init(struct st_data_s **core_data)
 925 {
 926         struct st_data_s *st_gdata;
 927         long err;
 928
 929         err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops);
 930         if (err) {
 931                 pr_err("error registering %d line discipline %ld",
 932                            N_TI_WL, err);
 933                 return err;
 934         }
 935         pr_debug("registered n_shared line discipline");
 936
 937         st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
 938         if (!st_gdata) {
 939                 pr_err("memory allocation failed");
 940                 err = tty_unregister_ldisc(N_TI_WL);
 941                 if (err)
 942                         pr_err("unable to un-register ldisc %ld", err);
 943                 err = -ENOMEM;
 944                 return err;
 945         }
 946
 947         /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
 948          * will be pushed in this queue for actual transmission.
 949          */
 950         skb_queue_head_init(&st_gdata->txq);
 951         skb_queue_head_init(&st_gdata->tx_waitq);
 952
 953         /* Locking used in st_int_enqueue() to avoid multiple execution */
 954         spin_lock_init(&st_gdata->lock);
 955
 956         err = st_ll_init(st_gdata);
 957         if (err) {
 958                 pr_err("error during st_ll initialization(%ld)", err);
 959                 kfree(st_gdata);
 960                 err = tty_unregister_ldisc(N_TI_WL);
 961                 if (err)
 962                         pr_err("unable to un-register ldisc");
 963                 return -1;
 964         }
 965         *core_data = st_gdata;
 966         return 0;
 967 }
 968
 969 void st_core_exit(struct st_data_s *st_gdata)
 970 {
 971         long err;
 972         /* internal module cleanup */
 973         err = st_ll_deinit(st_gdata);
 974         if (err)
 975                 pr_err("error during deinit of ST LL %ld", err);
 976
 977         if (st_gdata != NULL) {
 978                 /* Free ST Tx Qs and skbs */
 979                 skb_queue_purge(&st_gdata->txq);
 980                 skb_queue_purge(&st_gdata->tx_waitq);
 981                 kfree_skb(st_gdata->rx_skb);
 982                 kfree_skb(st_gdata->tx_skb);
 983                 /* TTY ldisc cleanup */
 984                 err = tty_unregister_ldisc(N_TI_WL);
 985                 if (err)
 986                         pr_err("unable to un-register ldisc %ld", err);
 987                 /* free the global data pointer */
 988                 kfree(st_gdata);
 989         }
 990 }
 991
 992