drivers/staging/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 Texas Instruments
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2 as
   8  *  published by the Free Software Foundation.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  */
  20
  21 #define pr_fmt(fmt)     "(stc): " fmt
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/init.h>
  25 #include <linux/tty.h>
  26
  27 /* understand BT, FM and GPS for now */
  28 #include <net/bluetooth/bluetooth.h>
  29 #include <net/bluetooth/hci_core.h>
  30 #include <net/bluetooth/hci.h>
  31 #include "fm.h"
  32 /*
  33  * packet formats for fm and gps
  34  * #include "gps.h"
  35  */
  36 #include "st_core.h"
  37 #include "st_kim.h"
  38 #include "st_ll.h"
  39 #include "st.h"
  40
  41 #define VERBOSE
  42 #ifdef DEBUG
  43 /* strings to be used for rfkill entries and by
  44  * ST Core to be used for sysfs debug entry
  45  */
  46 #define PROTO_ENTRY(type, name) name
  47 const unsigned char *protocol_strngs[] = {
  48         PROTO_ENTRY(ST_BT, "Bluetooth"),
  49         PROTO_ENTRY(ST_FM, "FM"),
  50         PROTO_ENTRY(ST_GPS, "GPS"),
  51 };
  52 #endif
  53 /* function pointer pointing to either,
  54  * st_kim_recv during registration to receive fw download responses
  55  * st_int_recv after registration to receive proto stack responses
  56  */
  57 void (*st_recv) (void*, const unsigned char*, long);
  58
  59 /********************************************************************/
  60 #if 0
  61 /* internal misc functions */
  62 bool is_protocol_list_empty(void)
  63 {
  64         unsigned char i = 0;
  65         pr_debug(" %s ", __func__);
  66         for (i = 0; i < ST_MAX; i++) {
  67                 if (st_gdata->list[i] != NULL)
  68                         return ST_NOTEMPTY;
  69                 /* not empty */
  70         }
  71         /* list empty */
  72         return ST_EMPTY;
  73 }
  74 #endif
  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 -1;
  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 void st_send_frame(enum proto_type protoid, struct st_data_s *st_gdata)
 105 {
 106         pr_info(" %s(prot:%d) ", __func__, protoid);
 107
 108         if (unlikely
 109             (st_gdata == NULL || st_gdata->rx_skb == NULL
 110              || st_gdata->list[protoid] == NULL)) {
 111                 pr_err("protocol %d not registered, no data to send?",
 112                            protoid);
 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[protoid]->recv != NULL)) {
 122                 if (unlikely
 123                         (st_gdata->list[protoid]->recv
 124                         (st_gdata->list[protoid]->priv_data, st_gdata->rx_skb)
 125                              != 0)) {
 126                         pr_err(" proto stack %d's ->recv failed", protoid);
 127                         kfree_skb(st_gdata->rx_skb);
 128                         return;
 129                 }
 130         } else {
 131                 pr_err(" proto stack %d's ->recv null", protoid);
 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  */
 142 void st_reg_complete(struct st_data_s *st_gdata, char err)
 143 {
 144         unsigned char i = 0;
 145         pr_info(" %s ", __func__);
 146         for (i = 0; i < ST_MAX; i++) {
 147                 if (likely(st_gdata != NULL && st_gdata->list[i] != NULL &&
 148                            st_gdata->list[i]->reg_complete_cb != NULL))
 149                         st_gdata->list[i]->reg_complete_cb
 150                                 (st_gdata->list[i]->priv_data, err);
 151         }
 152 }
 153
 154 static inline int st_check_data_len(struct st_data_s *st_gdata,
 155         int protoid, int len)
 156 {
 157         register int room = skb_tailroom(st_gdata->rx_skb);
 158
 159         pr_debug("len %d room %d", len, room);
 160
 161         if (!len) {
 162                 /* Received packet has only packet header and
 163                  * has zero length payload. So, ask ST CORE to
 164                  * forward the packet to protocol driver (BT/FM/GPS)
 165                  */
 166                 st_send_frame(protoid, st_gdata);
 167
 168         } else if (len > room) {
 169                 /* Received packet's payload length is larger.
 170                  * We can't accommodate it in created skb.
 171                  */
 172                 pr_err("Data length is too large len %d room %d", len,
 173                            room);
 174                 kfree_skb(st_gdata->rx_skb);
 175         } else {
 176                 /* Packet header has non-zero payload length and
 177                  * we have enough space in created skb. Lets read
 178                  * payload data */
 179                 st_gdata->rx_state = ST_BT_W4_DATA;
 180                 st_gdata->rx_count = len;
 181                 return len;
 182         }
 183
 184         /* Change ST state to continue to process next
 185          * packet */
 186         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 187         st_gdata->rx_skb = NULL;
 188         st_gdata->rx_count = 0;
 189
 190         return 0;
 191 }
 192
 193 /**
 194  * st_wakeup_ack - internal function for action when wake-up ack
 195  *      received
 196  */
 197 static inline void st_wakeup_ack(struct st_data_s *st_gdata,
 198         unsigned char cmd)
 199 {
 200         register struct sk_buff *waiting_skb;
 201         unsigned long flags = 0;
 202
 203         spin_lock_irqsave(&st_gdata->lock, flags);
 204         /* de-Q from waitQ and Q in txQ now that the
 205          * chip is awake
 206          */
 207         while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
 208                 skb_queue_tail(&st_gdata->txq, waiting_skb);
 209
 210         /* state forwarded to ST LL */
 211         st_ll_sleep_state(st_gdata, (unsigned long)cmd);
 212         spin_unlock_irqrestore(&st_gdata->lock, flags);
 213
 214         /* wake up to send the recently copied skbs from waitQ */
 215         st_tx_wakeup(st_gdata);
 216 }
 217
 218 /**
 219  * st_int_recv - ST's internal receive function.
 220  *      Decodes received RAW data and forwards to corresponding
 221  *      client drivers (Bluetooth,FM,GPS..etc).
 222  *      This can receive various types of packets,
 223  *      HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
 224  *      CH-8 packets from FM, CH-9 packets from GPS cores.
 225  */
 226 void st_int_recv(void *disc_data,
 227         const unsigned char *data, long count)
 228 {
 229         register char *ptr;
 230         struct hci_event_hdr *eh;
 231         struct hci_acl_hdr *ah;
 232         struct hci_sco_hdr *sh;
 233         struct fm_event_hdr *fm;
 234         struct gps_event_hdr *gps;
 235         register int len = 0, type = 0, dlen = 0;
 236         static enum proto_type protoid = ST_MAX;
 237         struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
 238
 239         ptr = (char *)data;
 240         /* tty_receive sent null ? */
 241         if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
 242                 pr_err(" received null from TTY ");
 243                 return;
 244         }
 245
 246         pr_info("count %ld rx_state %ld"
 247                    "rx_count %ld", count, st_gdata->rx_state,
 248                    st_gdata->rx_count);
 249
 250         /* Decode received bytes here */
 251         while (count) {
 252                 if (st_gdata->rx_count) {
 253                         len = min_t(unsigned int, st_gdata->rx_count, count);
 254                         memcpy(skb_put(st_gdata->rx_skb, len), ptr, len);
 255                         st_gdata->rx_count -= len;
 256                         count -= len;
 257                         ptr += len;
 258
 259                         if (st_gdata->rx_count)
 260                                 continue;
 261
 262                         /* Check ST RX state machine , where are we? */
 263                         switch (st_gdata->rx_state) {
 264
 265                                 /* Waiting for complete packet ? */
 266                         case ST_BT_W4_DATA:
 267                                 pr_debug("Complete pkt received");
 268
 269                                 /* Ask ST CORE to forward
 270                                  * the packet to protocol driver */
 271                                 st_send_frame(protoid, st_gdata);
 272
 273                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 274                                 st_gdata->rx_skb = NULL;
 275                                 protoid = ST_MAX;       /* is this required ? */
 276                                 continue;
 277
 278                                 /* Waiting for Bluetooth event header ? */
 279                         case ST_BT_W4_EVENT_HDR:
 280                                 eh = (struct hci_event_hdr *)st_gdata->rx_skb->
 281                                     data;
 282
 283                                 pr_debug("Event header: evt 0x%2.2x"
 284                                            "plen %d", eh->evt, eh->plen);
 285
 286                                 st_check_data_len(st_gdata, protoid, eh->plen);
 287                                 continue;
 288
 289                                 /* Waiting for Bluetooth acl header ? */
 290                         case ST_BT_W4_ACL_HDR:
 291                                 ah = (struct hci_acl_hdr *)st_gdata->rx_skb->
 292                                     data;
 293                                 dlen = __le16_to_cpu(ah->dlen);
 294
 295                                 pr_info("ACL header: dlen %d", dlen);
 296
 297                                 st_check_data_len(st_gdata, protoid, dlen);
 298                                 continue;
 299
 300                                 /* Waiting for Bluetooth sco header ? */
 301                         case ST_BT_W4_SCO_HDR:
 302                                 sh = (struct hci_sco_hdr *)st_gdata->rx_skb->
 303                                     data;
 304
 305                                 pr_info("SCO header: dlen %d", sh->dlen);
 306
 307                                 st_check_data_len(st_gdata, protoid, sh->dlen);
 308                                 continue;
 309                         case ST_FM_W4_EVENT_HDR:
 310                                 fm = (struct fm_event_hdr *)st_gdata->rx_skb->
 311                                     data;
 312                                 pr_info("FM Header: ");
 313                                 st_check_data_len(st_gdata, ST_FM, fm->plen);
 314                                 continue;
 315                                 /* TODO : Add GPS packet machine logic here */
 316                         case ST_GPS_W4_EVENT_HDR:
 317                                 /* [0x09 pkt hdr][R/W byte][2 byte len] */
 318                                 gps = (struct gps_event_hdr *)st_gdata->rx_skb->
 319                                      data;
 320                                 pr_info("GPS Header: ");
 321                                 st_check_data_len(st_gdata, ST_GPS, gps->plen);
 322                                 continue;
 323                         }       /* end of switch rx_state */
 324                 }
 325
 326                 /* end of if rx_count */
 327                 /* Check first byte of packet and identify module
 328                  * owner (BT/FM/GPS) */
 329                 switch (*ptr) {
 330
 331                         /* Bluetooth event packet? */
 332                 case HCI_EVENT_PKT:
 333                         pr_info("Event packet");
 334                         st_gdata->rx_state = ST_BT_W4_EVENT_HDR;
 335                         st_gdata->rx_count = HCI_EVENT_HDR_SIZE;
 336                         type = HCI_EVENT_PKT;
 337                         protoid = ST_BT;
 338                         break;
 339
 340                         /* Bluetooth acl packet? */
 341                 case HCI_ACLDATA_PKT:
 342                         pr_info("ACL packet");
 343                         st_gdata->rx_state = ST_BT_W4_ACL_HDR;
 344                         st_gdata->rx_count = HCI_ACL_HDR_SIZE;
 345                         type = HCI_ACLDATA_PKT;
 346                         protoid = ST_BT;
 347                         break;
 348
 349                         /* Bluetooth sco packet? */
 350                 case HCI_SCODATA_PKT:
 351                         pr_info("SCO packet");
 352                         st_gdata->rx_state = ST_BT_W4_SCO_HDR;
 353                         st_gdata->rx_count = HCI_SCO_HDR_SIZE;
 354                         type = HCI_SCODATA_PKT;
 355                         protoid = ST_BT;
 356                         break;
 357
 358                         /* Channel 8(FM) packet? */
 359                 case ST_FM_CH8_PKT:
 360                         pr_info("FM CH8 packet");
 361                         type = ST_FM_CH8_PKT;
 362                         st_gdata->rx_state = ST_FM_W4_EVENT_HDR;
 363                         st_gdata->rx_count = FM_EVENT_HDR_SIZE;
 364                         protoid = ST_FM;
 365                         break;
 366
 367                         /* Channel 9(GPS) packet? */
 368                 case 0x9:       /*ST_LL_GPS_CH9_PKT */
 369                         pr_info("GPS CH9 packet");
 370                         type = 0x9;     /* ST_LL_GPS_CH9_PKT; */
 371                         protoid = ST_GPS;
 372                         st_gdata->rx_state = ST_GPS_W4_EVENT_HDR;
 373                         st_gdata->rx_count = 3; /* GPS_EVENT_HDR_SIZE -1*/
 374                         break;
 375                 case LL_SLEEP_IND:
 376                 case LL_SLEEP_ACK:
 377                 case LL_WAKE_UP_IND:
 378                         pr_info("PM packet");
 379                         /* this takes appropriate action based on
 380                          * sleep state received --
 381                          */
 382                         st_ll_sleep_state(st_gdata, *ptr);
 383                         ptr++;
 384                         count--;
 385                         continue;
 386                 case LL_WAKE_UP_ACK:
 387                         pr_info("PM packet");
 388                         /* wake up ack received */
 389                         st_wakeup_ack(st_gdata, *ptr);
 390                         ptr++;
 391                         count--;
 392                         continue;
 393                         /* Unknow packet? */
 394                 default:
 395                         pr_err("Unknown packet type %2.2x", (__u8) *ptr);
 396                         ptr++;
 397                         count--;
 398                         continue;
 399                 };
 400                 ptr++;
 401                 count--;
 402
 403                 switch (protoid) {
 404                 case ST_BT:
 405                         /* Allocate new packet to hold received data */
 406                         st_gdata->rx_skb =
 407                             bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 408                         if (!st_gdata->rx_skb) {
 409                                 pr_err("Can't allocate mem for new packet");
 410                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 411                                 st_gdata->rx_count = 0;
 412                                 return;
 413                         }
 414                         bt_cb(st_gdata->rx_skb)->pkt_type = type;
 415                         break;
 416                 case ST_FM:     /* for FM */
 417                         st_gdata->rx_skb =
 418                             alloc_skb(FM_MAX_FRAME_SIZE, GFP_ATOMIC);
 419                         if (!st_gdata->rx_skb) {
 420                                 pr_err("Can't allocate mem for new packet");
 421                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 422                                 st_gdata->rx_count = 0;
 423                                 return;
 424                         }
 425                         /* place holder 0x08 */
 426                         skb_reserve(st_gdata->rx_skb, 1);
 427                         st_gdata->rx_skb->cb[0] = ST_FM_CH8_PKT;
 428                         break;
 429                 case ST_GPS:
 430                         /* for GPS */
 431                         st_gdata->rx_skb =
 432                             alloc_skb(100 /*GPS_MAX_FRAME_SIZE */ , GFP_ATOMIC);
 433                         if (!st_gdata->rx_skb) {
 434                                 pr_err("Can't allocate mem for new packet");
 435                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 436                                 st_gdata->rx_count = 0;
 437                                 return;
 438                         }
 439                         /* place holder 0x09 */
 440                         skb_reserve(st_gdata->rx_skb, 1);
 441                         st_gdata->rx_skb->cb[0] = 0x09; /*ST_GPS_CH9_PKT; */
 442                         break;
 443                 case ST_MAX:
 444                         break;
 445                 }
 446         }
 447         pr_debug("done %s", __func__);
 448         return;
 449 }
 450
 451 /**
 452  * st_int_dequeue - internal de-Q function.
 453  *      If the previous data set was not written
 454  *      completely, return that skb which has the pending data.
 455  *      In normal cases, return top of txq.
 456  */
 457 struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
 458 {
 459         struct sk_buff *returning_skb;
 460
 461         pr_debug("%s", __func__);
 462         if (st_gdata->tx_skb != NULL) {
 463                 returning_skb = st_gdata->tx_skb;
 464                 st_gdata->tx_skb = NULL;
 465                 return returning_skb;
 466         }
 467         return skb_dequeue(&st_gdata->txq);
 468 }
 469
 470 /**
 471  * st_int_enqueue - internal Q-ing function.
 472  *      Will either Q the skb to txq or the tx_waitq
 473  *      depending on the ST LL state.
 474  *      If the chip is asleep, then Q it onto waitq and
 475  *      wakeup the chip.
 476  *      txq and waitq needs protection since the other contexts
 477  *      may be sending data, waking up chip.
 478  */
 479 void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
 480 {
 481         unsigned long flags = 0;
 482
 483         pr_debug("%s", __func__);
 484         spin_lock_irqsave(&st_gdata->lock, flags);
 485
 486         switch (st_ll_getstate(st_gdata)) {
 487         case ST_LL_AWAKE:
 488                 pr_info("ST LL is AWAKE, sending normally");
 489                 skb_queue_tail(&st_gdata->txq, skb);
 490                 break;
 491         case ST_LL_ASLEEP_TO_AWAKE:
 492                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 493                 break;
 494         case ST_LL_AWAKE_TO_ASLEEP:
 495                 pr_err("ST LL is illegal state(%ld),"
 496                            "purging received skb.", st_ll_getstate(st_gdata));
 497                 kfree_skb(skb);
 498                 break;
 499         case ST_LL_ASLEEP:
 500                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 501                 st_ll_wakeup(st_gdata);
 502                 break;
 503         default:
 504                 pr_err("ST LL is illegal state(%ld),"
 505                            "purging received skb.", st_ll_getstate(st_gdata));
 506                 kfree_skb(skb);
 507                 break;
 508         }
 509
 510         spin_unlock_irqrestore(&st_gdata->lock, flags);
 511         pr_debug("done %s", __func__);
 512         return;
 513 }
 514
 515 /*
 516  * internal wakeup function
 517  * called from either
 518  * - TTY layer when write's finished
 519  * - st_write (in context of the protocol stack)
 520  */
 521 void st_tx_wakeup(struct st_data_s *st_data)
 522 {
 523         struct sk_buff *skb;
 524         unsigned long flags;    /* for irq save flags */
 525         pr_debug("%s", __func__);
 526         /* check for sending & set flag sending here */
 527         if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
 528                 pr_info("ST already sending");
 529                 /* keep sending */
 530                 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
 531                 return;
 532                 /* TX_WAKEUP will be checked in another
 533                  * context
 534                  */
 535         }
 536         do {                    /* come back if st_tx_wakeup is set */
 537                 /* woke-up to write */
 538                 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
 539                 while ((skb = st_int_dequeue(st_data))) {
 540                         int len;
 541                         spin_lock_irqsave(&st_data->lock, flags);
 542                         /* enable wake-up from TTY */
 543                         set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
 544                         len = st_int_write(st_data, skb->data, skb->len);
 545                         skb_pull(skb, len);
 546                         /* if skb->len = len as expected, skb->len=0 */
 547                         if (skb->len) {
 548                                 /* would be the next skb to be sent */
 549                                 st_data->tx_skb = skb;
 550                                 spin_unlock_irqrestore(&st_data->lock, flags);
 551                                 break;
 552                         }
 553                         kfree_skb(skb);
 554                         spin_unlock_irqrestore(&st_data->lock, flags);
 555                 }
 556                 /* if wake-up is set in another context- restart sending */
 557         } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
 558
 559         /* clear flag sending */
 560         clear_bit(ST_TX_SENDING, &st_data->tx_state);
 561 }
 562
 563 /********************************************************************/
 564 /* functions called from ST KIM
 565 */
 566 void kim_st_list_protocols(struct st_data_s *st_gdata, char *buf)
 567 {
 568         unsigned long flags = 0;
 569 #ifdef DEBUG
 570         unsigned char i = ST_MAX;
 571 #endif
 572         spin_lock_irqsave(&st_gdata->lock, flags);
 573 #ifdef DEBUG                    /* more detailed log */
 574         for (i = 0; i < ST_MAX; i++) {
 575                 if (i == 0) {
 576                         sprintf(buf, "%s is %s", protocol_strngs[i],
 577                                 st_gdata->list[i] !=
 578                                 NULL ? "Registered" : "Unregistered");
 579                 } else {
 580                         sprintf(buf, "%s\n%s is %s", buf, protocol_strngs[i],
 581                                 st_gdata->list[i] !=
 582                                 NULL ? "Registered" : "Unregistered");
 583                 }
 584         }
 585         sprintf(buf, "%s\n", buf);
 586 #else /* limited info */
 587         sprintf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
 588                         st_gdata->protos_registered,
 589                         st_gdata->list[ST_BT] != NULL ? 'R' : 'U',
 590                         st_gdata->list[ST_FM] != NULL ? 'R' : 'U',
 591                         st_gdata->list[ST_GPS] != NULL ? 'R' : 'U');
 592 #endif
 593         spin_unlock_irqrestore(&st_gdata->lock, flags);
 594 }
 595
 596 /********************************************************************/
 597 /*
 598  * functions called from protocol stack drivers
 599  * to be EXPORT-ed
 600  */
 601 long st_register(struct st_proto_s *new_proto)
 602 {
 603         struct st_data_s        *st_gdata;
 604         long err = 0;
 605         unsigned long flags = 0;
 606
 607         st_kim_ref(&st_gdata);
 608         pr_info("%s(%d) ", __func__, new_proto->type);
 609         if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
 610             || new_proto->reg_complete_cb == NULL) {
 611                 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
 612                 return -1;
 613         }
 614
 615         if (new_proto->type < ST_BT || new_proto->type >= ST_MAX) {
 616                 pr_err("protocol %d not supported", new_proto->type);
 617                 return -EPROTONOSUPPORT;
 618         }
 619
 620         if (st_gdata->list[new_proto->type] != NULL) {
 621                 pr_err("protocol %d already registered", new_proto->type);
 622                 return -EALREADY;
 623         }
 624
 625         /* can be from process context only */
 626         spin_lock_irqsave(&st_gdata->lock, flags);
 627
 628         if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
 629                 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->type);
 630                 /* fw download in progress */
 631                 st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 632
 633                 st_gdata->list[new_proto->type] = new_proto;
 634                 st_gdata->protos_registered++;
 635                 new_proto->write = st_write;
 636
 637                 set_bit(ST_REG_PENDING, &st_gdata->st_state);
 638                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 639                 return -EINPROGRESS;
 640         } else if (st_gdata->protos_registered == ST_EMPTY) {
 641                 pr_info(" protocol list empty :%d ", new_proto->type);
 642                 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 643                 st_recv = st_kim_recv;
 644
 645                 /* release lock previously held - re-locked below */
 646                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 647
 648                 /* enable the ST LL - to set default chip state */
 649                 st_ll_enable(st_gdata);
 650                 /* this may take a while to complete
 651                  * since it involves BT fw download
 652                  */
 653                 err = st_kim_start(st_gdata->kim_data);
 654                 if (err != 0) {
 655                         clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 656                         if ((st_gdata->protos_registered != ST_EMPTY) &&
 657                             (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 658                                 pr_err(" KIM failure complete callback ");
 659                                 st_reg_complete(st_gdata, -1);
 660                         }
 661
 662                         return -1;
 663                 }
 664
 665                 /* the protocol might require other gpios to be toggled
 666                  */
 667                 st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 668
 669                 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 670                 st_recv = st_int_recv;
 671
 672                 /* this is where all pending registration
 673                  * are signalled to be complete by calling callback functions
 674                  */
 675                 if ((st_gdata->protos_registered != ST_EMPTY) &&
 676                     (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 677                         pr_debug(" call reg complete callback ");
 678                         st_reg_complete(st_gdata, 0);
 679                 }
 680                 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
 681
 682                 /* check for already registered once more,
 683                  * since the above check is old
 684                  */
 685                 if (st_gdata->list[new_proto->type] != NULL) {
 686                         pr_err(" proto %d already registered ",
 687                                    new_proto->type);
 688                         return -EALREADY;
 689                 }
 690
 691                 spin_lock_irqsave(&st_gdata->lock, flags);
 692                 st_gdata->list[new_proto->type] = new_proto;
 693                 st_gdata->protos_registered++;
 694                 new_proto->write = st_write;
 695                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 696                 return err;
 697         }
 698         /* if fw is already downloaded & new stack registers protocol */
 699         else {
 700                 switch (new_proto->type) {
 701                 case ST_BT:
 702                         /* do nothing */
 703                         break;
 704                 case ST_FM:
 705                 case ST_GPS:
 706                         st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 707                         break;
 708                 case ST_MAX:
 709                 default:
 710                         pr_err("%d protocol not supported",
 711                                    new_proto->type);
 712                         err = -EPROTONOSUPPORT;
 713                         /* something wrong */
 714                         break;
 715                 }
 716                 st_gdata->list[new_proto->type] = new_proto;
 717                 st_gdata->protos_registered++;
 718                 new_proto->write = st_write;
 719
 720                 /* lock already held before entering else */
 721                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 722                 return err;
 723         }
 724         pr_debug("done %s(%d) ", __func__, new_proto->type);
 725 }
 726 EXPORT_SYMBOL_GPL(st_register);
 727
 728 /* to unregister a protocol -
 729  * to be called from protocol stack driver
 730  */
 731 long st_unregister(enum proto_type type)
 732 {
 733         long err = 0;
 734         unsigned long flags = 0;
 735         struct st_data_s        *st_gdata;
 736
 737         pr_debug("%s: %d ", __func__, type);
 738
 739         st_kim_ref(&st_gdata);
 740         if (type < ST_BT || type >= ST_MAX) {
 741                 pr_err(" protocol %d not supported", type);
 742                 return -EPROTONOSUPPORT;
 743         }
 744
 745         spin_lock_irqsave(&st_gdata->lock, flags);
 746
 747         if (st_gdata->list[type] == NULL) {
 748                 pr_err(" protocol %d not registered", type);
 749                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 750                 return -EPROTONOSUPPORT;
 751         }
 752
 753         st_gdata->protos_registered--;
 754         st_gdata->list[type] = NULL;
 755
 756         /* kim ignores BT in the below function
 757          * and handles the rest, BT is toggled
 758          * only in kim_start and kim_stop
 759          */
 760         st_kim_chip_toggle(type, KIM_GPIO_INACTIVE);
 761         spin_unlock_irqrestore(&st_gdata->lock, flags);
 762
 763         if ((st_gdata->protos_registered == ST_EMPTY) &&
 764             (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 765                 pr_info(" all protocols unregistered ");
 766
 767                 /* stop traffic on tty */
 768                 if (st_gdata->tty) {
 769                         tty_ldisc_flush(st_gdata->tty);
 770                         stop_tty(st_gdata->tty);
 771                 }
 772
 773                 /* all protocols now unregistered */
 774                 st_kim_stop(st_gdata->kim_data);
 775                 /* disable ST LL */
 776                 st_ll_disable(st_gdata);
 777         }
 778         return err;
 779 }
 780
 781 /*
 782  * called in protocol stack drivers
 783  * via the write function pointer
 784  */
 785 long st_write(struct sk_buff *skb)
 786 {
 787         struct st_data_s *st_gdata;
 788 #ifdef DEBUG
 789         enum proto_type protoid = ST_MAX;
 790 #endif
 791         long len;
 792
 793         st_kim_ref(&st_gdata);
 794         if (unlikely(skb == NULL || st_gdata == NULL
 795                 || st_gdata->tty == NULL)) {
 796                 pr_err("data/tty unavailable to perform write");
 797                 return -1;
 798         }
 799 #ifdef DEBUG                    /* open-up skb to read the 1st byte */
 800         switch (skb->data[0]) {
 801         case HCI_COMMAND_PKT:
 802         case HCI_ACLDATA_PKT:
 803         case HCI_SCODATA_PKT:
 804                 protoid = ST_BT;
 805                 break;
 806         case ST_FM_CH8_PKT:
 807                 protoid = ST_FM;
 808                 break;
 809         case 0x09:
 810                 protoid = ST_GPS;
 811                 break;
 812         }
 813         if (unlikely(st_gdata->list[protoid] == NULL)) {
 814                 pr_err(" protocol %d not registered, and writing? ",
 815                            protoid);
 816                 return -1;
 817         }
 818 #endif
 819         pr_debug("%d to be written", skb->len);
 820         len = skb->len;
 821
 822         /* st_ll to decide where to enqueue the skb */
 823         st_int_enqueue(st_gdata, skb);
 824         /* wake up */
 825         st_tx_wakeup(st_gdata);
 826
 827         /* return number of bytes written */
 828         return len;
 829 }
 830
 831 /* for protocols making use of shared transport */
 832 EXPORT_SYMBOL_GPL(st_unregister);
 833
 834 /********************************************************************/
 835 /*
 836  * functions called from TTY layer
 837  */
 838 static int st_tty_open(struct tty_struct *tty)
 839 {
 840         int err = 0;
 841         struct st_data_s *st_gdata;
 842         pr_info("%s ", __func__);
 843
 844         st_kim_ref(&st_gdata);
 845         st_gdata->tty = tty;
 846         tty->disc_data = st_gdata;
 847
 848         /* don't do an wakeup for now */
 849         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 850
 851         /* mem already allocated
 852          */
 853         tty->receive_room = 65536;
 854         /* Flush any pending characters in the driver and discipline. */
 855         tty_ldisc_flush(tty);
 856         tty_driver_flush_buffer(tty);
 857         /*
 858          * signal to UIM via KIM that -
 859          * installation of N_TI_WL ldisc is complete
 860          */
 861         st_kim_complete(st_gdata->kim_data);
 862         pr_debug("done %s", __func__);
 863         return err;
 864 }
 865
 866 static void st_tty_close(struct tty_struct *tty)
 867 {
 868         unsigned char i = ST_MAX;
 869         unsigned long flags = 0;
 870         struct  st_data_s *st_gdata = tty->disc_data;
 871
 872         pr_info("%s ", __func__);
 873
 874         /* TODO:
 875          * if a protocol has been registered & line discipline
 876          * un-installed for some reason - what should be done ?
 877          */
 878         spin_lock_irqsave(&st_gdata->lock, flags);
 879         for (i = ST_BT; i < ST_MAX; i++) {
 880                 if (st_gdata->list[i] != NULL)
 881                         pr_err("%d not un-registered", i);
 882                 st_gdata->list[i] = NULL;
 883         }
 884         st_gdata->protos_registered = 0;
 885         spin_unlock_irqrestore(&st_gdata->lock, flags);
 886         /*
 887          * signal to UIM via KIM that -
 888          * N_TI_WL ldisc is un-installed
 889          */
 890         st_kim_complete(st_gdata->kim_data);
 891         st_gdata->tty = NULL;
 892         /* Flush any pending characters in the driver and discipline. */
 893         tty_ldisc_flush(tty);
 894         tty_driver_flush_buffer(tty);
 895
 896         spin_lock_irqsave(&st_gdata->lock, flags);
 897         /* empty out txq and tx_waitq */
 898         skb_queue_purge(&st_gdata->txq);
 899         skb_queue_purge(&st_gdata->tx_waitq);
 900         /* reset the TTY Rx states of ST */
 901         st_gdata->rx_count = 0;
 902         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 903         kfree_skb(st_gdata->rx_skb);
 904         st_gdata->rx_skb = NULL;
 905         spin_unlock_irqrestore(&st_gdata->lock, flags);
 906
 907         pr_debug("%s: done ", __func__);
 908 }
 909
 910 static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
 911                            char *tty_flags, int count)
 912 {
 913
 914 #ifdef VERBOSE
 915         print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
 916                 16, 1, data, count, 0);
 917 #endif
 918
 919         /*
 920          * if fw download is in progress then route incoming data
 921          * to KIM for validation
 922          */
 923         st_recv(tty->disc_data, data, count);
 924         pr_debug("done %s", __func__);
 925 }
 926
 927 /* wake-up function called in from the TTY layer
 928  * inside the internal wakeup function will be called
 929  */
 930 static void st_tty_wakeup(struct tty_struct *tty)
 931 {
 932         struct  st_data_s *st_gdata = tty->disc_data;
 933         pr_debug("%s ", __func__);
 934         /* don't do an wakeup for now */
 935         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 936
 937         /* call our internal wakeup */
 938         st_tx_wakeup((void *)st_gdata);
 939 }
 940
 941 static void st_tty_flush_buffer(struct tty_struct *tty)
 942 {
 943         struct  st_data_s *st_gdata = tty->disc_data;
 944         pr_debug("%s ", __func__);
 945
 946         kfree_skb(st_gdata->tx_skb);
 947         st_gdata->tx_skb = NULL;
 948
 949         tty->ops->flush_buffer(tty);
 950         return;
 951 }
 952
 953 /********************************************************************/
 954 int st_core_init(struct st_data_s **core_data)
 955 {
 956         struct st_data_s *st_gdata;
 957         long err;
 958         static struct tty_ldisc_ops *st_ldisc_ops;
 959
 960         /* populate and register to TTY line discipline */
 961         st_ldisc_ops = kzalloc(sizeof(*st_ldisc_ops), GFP_KERNEL);
 962         if (!st_ldisc_ops) {
 963                 pr_err("no mem to allocate");
 964                 return -ENOMEM;
 965         }
 966
 967         st_ldisc_ops->magic = TTY_LDISC_MAGIC;
 968         st_ldisc_ops->name = "n_st";    /*"n_hci"; */
 969         st_ldisc_ops->open = st_tty_open;
 970         st_ldisc_ops->close = st_tty_close;
 971         st_ldisc_ops->receive_buf = st_tty_receive;
 972         st_ldisc_ops->write_wakeup = st_tty_wakeup;
 973         st_ldisc_ops->flush_buffer = st_tty_flush_buffer;
 974         st_ldisc_ops->owner = THIS_MODULE;
 975
 976         err = tty_register_ldisc(N_TI_WL, st_ldisc_ops);
 977         if (err) {
 978                 pr_err("error registering %d line discipline %ld",
 979                            N_TI_WL, err);
 980                 kfree(st_ldisc_ops);
 981                 return err;
 982         }
 983         pr_debug("registered n_shared line discipline");
 984
 985         st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
 986         if (!st_gdata) {
 987                 pr_err("memory allocation failed");
 988                 err = tty_unregister_ldisc(N_TI_WL);
 989                 if (err)
 990                         pr_err("unable to un-register ldisc %ld", err);
 991                 kfree(st_ldisc_ops);
 992                 err = -ENOMEM;
 993                 return err;
 994         }
 995
 996         /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
 997          * will be pushed in this queue for actual transmission.
 998          */
 999         skb_queue_head_init(&st_gdata->txq);
1000         skb_queue_head_init(&st_gdata->tx_waitq);
1001
1002         /* Locking used in st_int_enqueue() to avoid multiple execution */
1003         spin_lock_init(&st_gdata->lock);
1004
1005         /* ldisc_ops ref to be only used in __exit of module */
1006         st_gdata->ldisc_ops = st_ldisc_ops;
1007
1008 #if 0
1009         err = st_kim_init();
1010         if (err) {
1011                 pr_err("error during kim initialization(%ld)", err);
1012                 kfree(st_gdata);
1013                 err = tty_unregister_ldisc(N_TI_WL);
1014                 if (err)
1015                         pr_err("unable to un-register ldisc");
1016                 kfree(st_ldisc_ops);
1017                 return -1;
1018         }
1019 #endif
1020
1021         err = st_ll_init(st_gdata);
1022         if (err) {
1023                 pr_err("error during st_ll initialization(%ld)", err);
1024                 kfree(st_gdata);
1025                 err = tty_unregister_ldisc(N_TI_WL);
1026                 if (err)
1027                         pr_err("unable to un-register ldisc");
1028                 kfree(st_ldisc_ops);
1029                 return -1;
1030         }
1031         *core_data = st_gdata;
1032         return 0;
1033 }
1034
1035 void st_core_exit(struct st_data_s *st_gdata)
1036 {
1037         long err;
1038         /* internal module cleanup */
1039         err = st_ll_deinit(st_gdata);
1040         if (err)
1041                 pr_err("error during deinit of ST LL %ld", err);
1042 #if 0
1043         err = st_kim_deinit();
1044         if (err)
1045                 pr_err("error during deinit of ST KIM %ld", err);
1046 #endif
1047         if (st_gdata != NULL) {
1048                 /* Free ST Tx Qs and skbs */
1049                 skb_queue_purge(&st_gdata->txq);
1050                 skb_queue_purge(&st_gdata->tx_waitq);
1051                 kfree_skb(st_gdata->rx_skb);
1052                 kfree_skb(st_gdata->tx_skb);
1053                 /* TTY ldisc cleanup */
1054                 err = tty_unregister_ldisc(N_TI_WL);
1055                 if (err)
1056                         pr_err("unable to un-register ldisc %ld", err);
1057                 kfree(st_gdata->ldisc_ops);
1058                 /* free the global data pointer */
1059                 kfree(st_gdata);
1060         }
1061 }
1062
1063