release/src-rt-6.x.4708/linux/linux-2.6.36/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 /* strings to be used for rfkill entries and by
  42  * ST Core to be used for sysfs debug entry
  43  */
  44 #define PROTO_ENTRY(type, name) name
  45 const unsigned char *protocol_strngs[] = {
  46         PROTO_ENTRY(ST_BT, "Bluetooth"),
  47         PROTO_ENTRY(ST_FM, "FM"),
  48         PROTO_ENTRY(ST_GPS, "GPS"),
  49 };
  50 /* function pointer pointing to either,
  51  * st_kim_recv during registration to receive fw download responses
  52  * st_int_recv after registration to receive proto stack responses
  53  */
  54 void (*st_recv) (void*, const unsigned char*, long);
  55
  56 /********************************************************************/
  57
  58 /* can be called in from
  59  * -- KIM (during fw download)
  60  * -- ST Core (during st_write)
  61  *
  62  *  This is the internal write function - a wrapper
  63  *  to tty->ops->write
  64  */
  65 int st_int_write(struct st_data_s *st_gdata,
  66         const unsigned char *data, int count)
  67 {
  68         struct tty_struct *tty;
  69         if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
  70                 pr_err("tty unavailable to perform write");
  71                 return -1;
  72         }
  73         tty = st_gdata->tty;
  74 #ifdef VERBOSE
  75         print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
  76                 16, 1, data, count, 0);
  77 #endif
  78         return tty->ops->write(tty, data, count);
  79
  80 }
  81
  82 /*
  83  * push the skb received to relevant
  84  * protocol stacks
  85  */
  86 void st_send_frame(enum proto_type protoid, struct st_data_s *st_gdata)
  87 {
  88         pr_info(" %s(prot:%d) ", __func__, protoid);
  89
  90         if (unlikely
  91             (st_gdata == NULL || st_gdata->rx_skb == NULL
  92              || st_gdata->list[protoid] == NULL)) {
  93                 pr_err("protocol %d not registered, no data to send?",
  94                            protoid);
  95                 kfree_skb(st_gdata->rx_skb);
  96                 return;
  97         }
  98         /* this cannot fail
  99          * this shouldn't take long
 100          * - should be just skb_queue_tail for the
 101          *   protocol stack driver
 102          */
 103         if (likely(st_gdata->list[protoid]->recv != NULL)) {
 104                 if (unlikely
 105                         (st_gdata->list[protoid]->recv
 106                         (st_gdata->list[protoid]->priv_data, st_gdata->rx_skb)
 107                              != 0)) {
 108                         pr_err(" proto stack %d's ->recv failed", protoid);
 109                         kfree_skb(st_gdata->rx_skb);
 110                         return;
 111                 }
 112         } else {
 113                 pr_err(" proto stack %d's ->recv null", protoid);
 114                 kfree_skb(st_gdata->rx_skb);
 115         }
 116         return;
 117 }
 118
 119 /**
 120  * st_reg_complete -
 121  * to call registration complete callbacks
 122  * of all protocol stack drivers
 123  */
 124 void st_reg_complete(struct st_data_s *st_gdata, char err)
 125 {
 126         unsigned char i = 0;
 127         pr_info(" %s ", __func__);
 128         for (i = 0; i < ST_MAX; i++) {
 129                 if (likely(st_gdata != NULL && st_gdata->list[i] != NULL &&
 130                            st_gdata->list[i]->reg_complete_cb != NULL))
 131                         st_gdata->list[i]->reg_complete_cb
 132                                 (st_gdata->list[i]->priv_data, err);
 133         }
 134 }
 135
 136 static inline int st_check_data_len(struct st_data_s *st_gdata,
 137         int protoid, int len)
 138 {
 139         register int room = skb_tailroom(st_gdata->rx_skb);
 140
 141         pr_debug("len %d room %d", len, room);
 142
 143         if (!len) {
 144                 /* Received packet has only packet header and
 145                  * has zero length payload. So, ask ST CORE to
 146                  * forward the packet to protocol driver (BT/FM/GPS)
 147                  */
 148                 st_send_frame(protoid, st_gdata);
 149
 150         } else if (len > room) {
 151                 /* Received packet's payload length is larger.
 152                  * We can't accommodate it in created skb.
 153                  */
 154                 pr_err("Data length is too large len %d room %d", len,
 155                            room);
 156                 kfree_skb(st_gdata->rx_skb);
 157         } else {
 158                 /* Packet header has non-zero payload length and
 159                  * we have enough space in created skb. Lets read
 160                  * payload data */
 161                 st_gdata->rx_state = ST_BT_W4_DATA;
 162                 st_gdata->rx_count = len;
 163                 return len;
 164         }
 165
 166         /* Change ST state to continue to process next
 167          * packet */
 168         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 169         st_gdata->rx_skb = NULL;
 170         st_gdata->rx_count = 0;
 171
 172         return 0;
 173 }
 174
 175 /**
 176  * st_wakeup_ack - internal function for action when wake-up ack
 177  *      received
 178  */
 179 static inline void st_wakeup_ack(struct st_data_s *st_gdata,
 180         unsigned char cmd)
 181 {
 182         register struct sk_buff *waiting_skb;
 183         unsigned long flags = 0;
 184
 185         spin_lock_irqsave(&st_gdata->lock, flags);
 186         /* de-Q from waitQ and Q in txQ now that the
 187          * chip is awake
 188          */
 189         while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
 190                 skb_queue_tail(&st_gdata->txq, waiting_skb);
 191
 192         /* state forwarded to ST LL */
 193         st_ll_sleep_state(st_gdata, (unsigned long)cmd);
 194         spin_unlock_irqrestore(&st_gdata->lock, flags);
 195
 196         /* wake up to send the recently copied skbs from waitQ */
 197         st_tx_wakeup(st_gdata);
 198 }
 199
 200 /**
 201  * st_int_recv - ST's internal receive function.
 202  *      Decodes received RAW data and forwards to corresponding
 203  *      client drivers (Bluetooth,FM,GPS..etc).
 204  *      This can receive various types of packets,
 205  *      HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
 206  *      CH-8 packets from FM, CH-9 packets from GPS cores.
 207  */
 208 void st_int_recv(void *disc_data,
 209         const unsigned char *data, long count)
 210 {
 211         register char *ptr;
 212         struct hci_event_hdr *eh;
 213         struct hci_acl_hdr *ah;
 214         struct hci_sco_hdr *sh;
 215         struct fm_event_hdr *fm;
 216         struct gps_event_hdr *gps;
 217         register int len = 0, type = 0, dlen = 0;
 218         static enum proto_type protoid = ST_MAX;
 219         struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
 220
 221         ptr = (char *)data;
 222         /* tty_receive sent null ? */
 223         if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
 224                 pr_err(" received null from TTY ");
 225                 return;
 226         }
 227
 228         pr_info("count %ld rx_state %ld"
 229                    "rx_count %ld", count, st_gdata->rx_state,
 230                    st_gdata->rx_count);
 231
 232         /* Decode received bytes here */
 233         while (count) {
 234                 if (st_gdata->rx_count) {
 235                         len = min_t(unsigned int, st_gdata->rx_count, count);
 236                         memcpy(skb_put(st_gdata->rx_skb, len), ptr, len);
 237                         st_gdata->rx_count -= len;
 238                         count -= len;
 239                         ptr += len;
 240
 241                         if (st_gdata->rx_count)
 242                                 continue;
 243
 244                         /* Check ST RX state machine , where are we? */
 245                         switch (st_gdata->rx_state) {
 246
 247                                 /* Waiting for complete packet ? */
 248                         case ST_BT_W4_DATA:
 249                                 pr_debug("Complete pkt received");
 250
 251                                 /* Ask ST CORE to forward
 252                                  * the packet to protocol driver */
 253                                 st_send_frame(protoid, st_gdata);
 254
 255                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 256                                 st_gdata->rx_skb = NULL;
 257                                 protoid = ST_MAX;       /* is this required ? */
 258                                 continue;
 259
 260                                 /* Waiting for Bluetooth event header ? */
 261                         case ST_BT_W4_EVENT_HDR:
 262                                 eh = (struct hci_event_hdr *)st_gdata->rx_skb->
 263                                     data;
 264
 265                                 pr_debug("Event header: evt 0x%2.2x"
 266                                            "plen %d", eh->evt, eh->plen);
 267
 268                                 st_check_data_len(st_gdata, protoid, eh->plen);
 269                                 continue;
 270
 271                                 /* Waiting for Bluetooth acl header ? */
 272                         case ST_BT_W4_ACL_HDR:
 273                                 ah = (struct hci_acl_hdr *)st_gdata->rx_skb->
 274                                     data;
 275                                 dlen = __le16_to_cpu(ah->dlen);
 276
 277                                 pr_info("ACL header: dlen %d", dlen);
 278
 279                                 st_check_data_len(st_gdata, protoid, dlen);
 280                                 continue;
 281
 282                                 /* Waiting for Bluetooth sco header ? */
 283                         case ST_BT_W4_SCO_HDR:
 284                                 sh = (struct hci_sco_hdr *)st_gdata->rx_skb->
 285                                     data;
 286
 287                                 pr_info("SCO header: dlen %d", sh->dlen);
 288
 289                                 st_check_data_len(st_gdata, protoid, sh->dlen);
 290                                 continue;
 291                         case ST_FM_W4_EVENT_HDR:
 292                                 fm = (struct fm_event_hdr *)st_gdata->rx_skb->
 293                                     data;
 294                                 pr_info("FM Header: ");
 295                                 st_check_data_len(st_gdata, ST_FM, fm->plen);
 296                                 continue;
 297                                 /* TODO : Add GPS packet machine logic here */
 298                         case ST_GPS_W4_EVENT_HDR:
 299                                 /* [0x09 pkt hdr][R/W byte][2 byte len] */
 300                                 gps = (struct gps_event_hdr *)st_gdata->rx_skb->
 301                                      data;
 302                                 pr_info("GPS Header: ");
 303                                 st_check_data_len(st_gdata, ST_GPS, gps->plen);
 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
 313                         /* Bluetooth event packet? */
 314                 case HCI_EVENT_PKT:
 315                         pr_info("Event packet");
 316                         st_gdata->rx_state = ST_BT_W4_EVENT_HDR;
 317                         st_gdata->rx_count = HCI_EVENT_HDR_SIZE;
 318                         type = HCI_EVENT_PKT;
 319                         protoid = ST_BT;
 320                         break;
 321
 322                         /* Bluetooth acl packet? */
 323                 case HCI_ACLDATA_PKT:
 324                         pr_info("ACL packet");
 325                         st_gdata->rx_state = ST_BT_W4_ACL_HDR;
 326                         st_gdata->rx_count = HCI_ACL_HDR_SIZE;
 327                         type = HCI_ACLDATA_PKT;
 328                         protoid = ST_BT;
 329                         break;
 330
 331                         /* Bluetooth sco packet? */
 332                 case HCI_SCODATA_PKT:
 333                         pr_info("SCO packet");
 334                         st_gdata->rx_state = ST_BT_W4_SCO_HDR;
 335                         st_gdata->rx_count = HCI_SCO_HDR_SIZE;
 336                         type = HCI_SCODATA_PKT;
 337                         protoid = ST_BT;
 338                         break;
 339
 340                         /* Channel 8(FM) packet? */
 341                 case ST_FM_CH8_PKT:
 342                         pr_info("FM CH8 packet");
 343                         type = ST_FM_CH8_PKT;
 344                         st_gdata->rx_state = ST_FM_W4_EVENT_HDR;
 345                         st_gdata->rx_count = FM_EVENT_HDR_SIZE;
 346                         protoid = ST_FM;
 347                         break;
 348
 349                         /* Channel 9(GPS) packet? */
 350                 case 0x9:       /*ST_LL_GPS_CH9_PKT */
 351                         pr_info("GPS CH9 packet");
 352                         type = 0x9;     /* ST_LL_GPS_CH9_PKT; */
 353                         protoid = ST_GPS;
 354                         st_gdata->rx_state = ST_GPS_W4_EVENT_HDR;
 355                         st_gdata->rx_count = 3; /* GPS_EVENT_HDR_SIZE -1*/
 356                         break;
 357                 case LL_SLEEP_IND:
 358                 case LL_SLEEP_ACK:
 359                 case LL_WAKE_UP_IND:
 360                         pr_info("PM packet");
 361                         /* this takes appropriate action based on
 362                          * sleep state received --
 363                          */
 364                         st_ll_sleep_state(st_gdata, *ptr);
 365                         ptr++;
 366                         count--;
 367                         continue;
 368                 case LL_WAKE_UP_ACK:
 369                         pr_info("PM packet");
 370                         /* wake up ack received */
 371                         st_wakeup_ack(st_gdata, *ptr);
 372                         ptr++;
 373                         count--;
 374                         continue;
 375                         /* Unknow packet? */
 376                 default:
 377                         pr_err("Unknown packet type %2.2x", (__u8) *ptr);
 378                         ptr++;
 379                         count--;
 380                         continue;
 381                 };
 382                 ptr++;
 383                 count--;
 384
 385                 switch (protoid) {
 386                 case ST_BT:
 387                         /* Allocate new packet to hold received data */
 388                         st_gdata->rx_skb =
 389                             bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 390                         if (!st_gdata->rx_skb) {
 391                                 pr_err("Can't allocate mem for new packet");
 392                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 393                                 st_gdata->rx_count = 0;
 394                                 return;
 395                         }
 396                         bt_cb(st_gdata->rx_skb)->pkt_type = type;
 397                         break;
 398                 case ST_FM:     /* for FM */
 399                         st_gdata->rx_skb =
 400                             alloc_skb(FM_MAX_FRAME_SIZE, GFP_ATOMIC);
 401                         if (!st_gdata->rx_skb) {
 402                                 pr_err("Can't allocate mem for new packet");
 403                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 404                                 st_gdata->rx_count = 0;
 405                                 return;
 406                         }
 407                         /* place holder 0x08 */
 408                         skb_reserve(st_gdata->rx_skb, 1);
 409                         st_gdata->rx_skb->cb[0] = ST_FM_CH8_PKT;
 410                         break;
 411                 case ST_GPS:
 412                         /* for GPS */
 413                         st_gdata->rx_skb =
 414                             alloc_skb(100 /*GPS_MAX_FRAME_SIZE */ , GFP_ATOMIC);
 415                         if (!st_gdata->rx_skb) {
 416                                 pr_err("Can't allocate mem for new packet");
 417                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 418                                 st_gdata->rx_count = 0;
 419                                 return;
 420                         }
 421                         /* place holder 0x09 */
 422                         skb_reserve(st_gdata->rx_skb, 1);
 423                         st_gdata->rx_skb->cb[0] = 0x09; /*ST_GPS_CH9_PKT; */
 424                         break;
 425                 case ST_MAX:
 426                         break;
 427                 }
 428         }
 429         pr_debug("done %s", __func__);
 430         return;
 431 }
 432
 433 /**
 434  * st_int_dequeue - internal de-Q function.
 435  *      If the previous data set was not written
 436  *      completely, return that skb which has the pending data.
 437  *      In normal cases, return top of txq.
 438  */
 439 struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
 440 {
 441         struct sk_buff *returning_skb;
 442
 443         pr_debug("%s", __func__);
 444         if (st_gdata->tx_skb != NULL) {
 445                 returning_skb = st_gdata->tx_skb;
 446                 st_gdata->tx_skb = NULL;
 447                 return returning_skb;
 448         }
 449         return skb_dequeue(&st_gdata->txq);
 450 }
 451
 452 /**
 453  * st_int_enqueue - internal Q-ing function.
 454  *      Will either Q the skb to txq or the tx_waitq
 455  *      depending on the ST LL state.
 456  *      If the chip is asleep, then Q it onto waitq and
 457  *      wakeup the chip.
 458  *      txq and waitq needs protection since the other contexts
 459  *      may be sending data, waking up chip.
 460  */
 461 void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
 462 {
 463         unsigned long flags = 0;
 464
 465         pr_debug("%s", __func__);
 466         spin_lock_irqsave(&st_gdata->lock, flags);
 467
 468         switch (st_ll_getstate(st_gdata)) {
 469         case ST_LL_AWAKE:
 470                 pr_info("ST LL is AWAKE, sending normally");
 471                 skb_queue_tail(&st_gdata->txq, skb);
 472                 break;
 473         case ST_LL_ASLEEP_TO_AWAKE:
 474                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 475                 break;
 476         case ST_LL_AWAKE_TO_ASLEEP:
 477                 pr_err("ST LL is illegal state(%ld),"
 478                            "purging received skb.", st_ll_getstate(st_gdata));
 479                 kfree_skb(skb);
 480                 break;
 481         case ST_LL_ASLEEP:
 482                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 483                 st_ll_wakeup(st_gdata);
 484                 break;
 485         default:
 486                 pr_err("ST LL is illegal state(%ld),"
 487                            "purging received skb.", st_ll_getstate(st_gdata));
 488                 kfree_skb(skb);
 489                 break;
 490         }
 491
 492         spin_unlock_irqrestore(&st_gdata->lock, flags);
 493         pr_debug("done %s", __func__);
 494         return;
 495 }
 496
 497 /*
 498  * internal wakeup function
 499  * called from either
 500  * - TTY layer when write's finished
 501  * - st_write (in context of the protocol stack)
 502  */
 503 void st_tx_wakeup(struct st_data_s *st_data)
 504 {
 505         struct sk_buff *skb;
 506         unsigned long flags;    /* for irq save flags */
 507         pr_debug("%s", __func__);
 508         /* check for sending & set flag sending here */
 509         if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
 510                 pr_info("ST already sending");
 511                 /* keep sending */
 512                 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
 513                 return;
 514                 /* TX_WAKEUP will be checked in another
 515                  * context
 516                  */
 517         }
 518         do {                    /* come back if st_tx_wakeup is set */
 519                 /* woke-up to write */
 520                 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
 521                 while ((skb = st_int_dequeue(st_data))) {
 522                         int len;
 523                         spin_lock_irqsave(&st_data->lock, flags);
 524                         /* enable wake-up from TTY */
 525                         set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
 526                         len = st_int_write(st_data, skb->data, skb->len);
 527                         skb_pull(skb, len);
 528                         /* if skb->len = len as expected, skb->len=0 */
 529                         if (skb->len) {
 530                                 /* would be the next skb to be sent */
 531                                 st_data->tx_skb = skb;
 532                                 spin_unlock_irqrestore(&st_data->lock, flags);
 533                                 break;
 534                         }
 535                         kfree_skb(skb);
 536                         spin_unlock_irqrestore(&st_data->lock, flags);
 537                 }
 538                 /* if wake-up is set in another context- restart sending */
 539         } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
 540
 541         /* clear flag sending */
 542         clear_bit(ST_TX_SENDING, &st_data->tx_state);
 543 }
 544
 545 /********************************************************************/
 546 /* functions called from ST KIM
 547 */
 548 void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
 549 {
 550         seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
 551                         st_gdata->protos_registered,
 552                         st_gdata->list[ST_BT] != NULL ? 'R' : 'U',
 553                         st_gdata->list[ST_FM] != NULL ? 'R' : 'U',
 554                         st_gdata->list[ST_GPS] != NULL ? 'R' : 'U');
 555 }
 556
 557 /********************************************************************/
 558 /*
 559  * functions called from protocol stack drivers
 560  * to be EXPORT-ed
 561  */
 562 long st_register(struct st_proto_s *new_proto)
 563 {
 564         struct st_data_s        *st_gdata;
 565         long err = 0;
 566         unsigned long flags = 0;
 567
 568         st_kim_ref(&st_gdata, 0);
 569         pr_info("%s(%d) ", __func__, new_proto->type);
 570         if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
 571             || new_proto->reg_complete_cb == NULL) {
 572                 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
 573                 return -1;
 574         }
 575
 576         if (new_proto->type < ST_BT || new_proto->type >= ST_MAX) {
 577                 pr_err("protocol %d not supported", new_proto->type);
 578                 return -EPROTONOSUPPORT;
 579         }
 580
 581         if (st_gdata->list[new_proto->type] != NULL) {
 582                 pr_err("protocol %d already registered", new_proto->type);
 583                 return -EALREADY;
 584         }
 585
 586         /* can be from process context only */
 587         spin_lock_irqsave(&st_gdata->lock, flags);
 588
 589         if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
 590                 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->type);
 591                 /* fw download in progress */
 592                 st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 593
 594                 st_gdata->list[new_proto->type] = new_proto;
 595                 st_gdata->protos_registered++;
 596                 new_proto->write = st_write;
 597
 598                 set_bit(ST_REG_PENDING, &st_gdata->st_state);
 599                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 600                 return -EINPROGRESS;
 601         } else if (st_gdata->protos_registered == ST_EMPTY) {
 602                 pr_info(" protocol list empty :%d ", new_proto->type);
 603                 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 604                 st_recv = st_kim_recv;
 605
 606                 /* release lock previously held - re-locked below */
 607                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 608
 609                 /* enable the ST LL - to set default chip state */
 610                 st_ll_enable(st_gdata);
 611                 /* this may take a while to complete
 612                  * since it involves BT fw download
 613                  */
 614                 err = st_kim_start(st_gdata->kim_data);
 615                 if (err != 0) {
 616                         clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 617                         if ((st_gdata->protos_registered != ST_EMPTY) &&
 618                             (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 619                                 pr_err(" KIM failure complete callback ");
 620                                 st_reg_complete(st_gdata, -1);
 621                         }
 622
 623                         return -1;
 624                 }
 625
 626                 /* the protocol might require other gpios to be toggled
 627                  */
 628                 st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 629
 630                 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 631                 st_recv = st_int_recv;
 632
 633                 /* this is where all pending registration
 634                  * are signalled to be complete by calling callback functions
 635                  */
 636                 if ((st_gdata->protos_registered != ST_EMPTY) &&
 637                     (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 638                         pr_debug(" call reg complete callback ");
 639                         st_reg_complete(st_gdata, 0);
 640                 }
 641                 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
 642
 643                 /* check for already registered once more,
 644                  * since the above check is old
 645                  */
 646                 if (st_gdata->list[new_proto->type] != NULL) {
 647                         pr_err(" proto %d already registered ",
 648                                    new_proto->type);
 649                         return -EALREADY;
 650                 }
 651
 652                 spin_lock_irqsave(&st_gdata->lock, flags);
 653                 st_gdata->list[new_proto->type] = new_proto;
 654                 st_gdata->protos_registered++;
 655                 new_proto->write = st_write;
 656                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 657                 return err;
 658         }
 659         /* if fw is already downloaded & new stack registers protocol */
 660         else {
 661                 switch (new_proto->type) {
 662                 case ST_BT:
 663                         /* do nothing */
 664                         break;
 665                 case ST_FM:
 666                 case ST_GPS:
 667                         st_kim_chip_toggle(new_proto->type, KIM_GPIO_ACTIVE);
 668                         break;
 669                 case ST_MAX:
 670                 default:
 671                         pr_err("%d protocol not supported",
 672                                    new_proto->type);
 673                         err = -EPROTONOSUPPORT;
 674                         /* something wrong */
 675                         break;
 676                 }
 677                 st_gdata->list[new_proto->type] = new_proto;
 678                 st_gdata->protos_registered++;
 679                 new_proto->write = st_write;
 680
 681                 /* lock already held before entering else */
 682                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 683                 return err;
 684         }
 685         pr_debug("done %s(%d) ", __func__, new_proto->type);
 686 }
 687 EXPORT_SYMBOL_GPL(st_register);
 688
 689 /* to unregister a protocol -
 690  * to be called from protocol stack driver
 691  */
 692 long st_unregister(enum proto_type type)
 693 {
 694         long err = 0;
 695         unsigned long flags = 0;
 696         struct st_data_s        *st_gdata;
 697
 698         pr_debug("%s: %d ", __func__, type);
 699
 700         st_kim_ref(&st_gdata, 0);
 701         if (type < ST_BT || type >= ST_MAX) {
 702                 pr_err(" protocol %d not supported", type);
 703                 return -EPROTONOSUPPORT;
 704         }
 705
 706         spin_lock_irqsave(&st_gdata->lock, flags);
 707
 708         if (st_gdata->list[type] == NULL) {
 709                 pr_err(" protocol %d not registered", type);
 710                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 711                 return -EPROTONOSUPPORT;
 712         }
 713
 714         st_gdata->protos_registered--;
 715         st_gdata->list[type] = NULL;
 716
 717         /* kim ignores BT in the below function
 718          * and handles the rest, BT is toggled
 719          * only in kim_start and kim_stop
 720          */
 721         st_kim_chip_toggle(type, KIM_GPIO_INACTIVE);
 722         spin_unlock_irqrestore(&st_gdata->lock, flags);
 723
 724         if ((st_gdata->protos_registered == ST_EMPTY) &&
 725             (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 726                 pr_info(" all protocols unregistered ");
 727
 728                 /* stop traffic on tty */
 729                 if (st_gdata->tty) {
 730                         tty_ldisc_flush(st_gdata->tty);
 731                         stop_tty(st_gdata->tty);
 732                 }
 733
 734                 /* all protocols now unregistered */
 735                 st_kim_stop(st_gdata->kim_data);
 736                 /* disable ST LL */
 737                 st_ll_disable(st_gdata);
 738         }
 739         return err;
 740 }
 741
 742 /*
 743  * called in protocol stack drivers
 744  * via the write function pointer
 745  */
 746 long st_write(struct sk_buff *skb)
 747 {
 748         struct st_data_s *st_gdata;
 749 #ifdef DEBUG
 750         enum proto_type protoid = ST_MAX;
 751 #endif
 752         long len;
 753
 754         st_kim_ref(&st_gdata, 0);
 755         if (unlikely(skb == NULL || st_gdata == NULL
 756                 || st_gdata->tty == NULL)) {
 757                 pr_err("data/tty unavailable to perform write");
 758                 return -1;
 759         }
 760 #ifdef DEBUG                        /* open-up skb to read the 1st byte */
 761         switch (skb->data[0]) {
 762         case HCI_COMMAND_PKT:
 763         case HCI_ACLDATA_PKT:
 764         case HCI_SCODATA_PKT:
 765                 protoid = ST_BT;
 766                 break;
 767         case ST_FM_CH8_PKT:
 768                 protoid = ST_FM;
 769                 break;
 770         case 0x09:
 771                 protoid = ST_GPS;
 772                 break;
 773         }
 774         if (unlikely(st_gdata->list[protoid] == NULL)) {
 775                 pr_err(" protocol %d not registered, and writing? ",
 776                            protoid);
 777                 return -1;
 778         }
 779 #endif
 780         pr_debug("%d to be written", skb->len);
 781         len = skb->len;
 782
 783         /* st_ll to decide where to enqueue the skb */
 784         st_int_enqueue(st_gdata, skb);
 785         /* wake up */
 786         st_tx_wakeup(st_gdata);
 787
 788         /* return number of bytes written */
 789         return len;
 790 }
 791
 792 /* for protocols making use of shared transport */
 793 EXPORT_SYMBOL_GPL(st_unregister);
 794
 795 /********************************************************************/
 796 /*
 797  * functions called from TTY layer
 798  */
 799 static int st_tty_open(struct tty_struct *tty)
 800 {
 801         int err = 0;
 802         struct st_data_s *st_gdata;
 803         pr_info("%s ", __func__);
 804
 805         st_kim_ref(&st_gdata, 0);
 806         st_gdata->tty = tty;
 807         tty->disc_data = st_gdata;
 808
 809         /* don't do an wakeup for now */
 810         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 811
 812         /* mem already allocated
 813          */
 814         tty->receive_room = 65536;
 815         /* Flush any pending characters in the driver and discipline. */
 816         tty_ldisc_flush(tty);
 817         tty_driver_flush_buffer(tty);
 818         /*
 819          * signal to UIM via KIM that -
 820          * installation of N_TI_WL ldisc is complete
 821          */
 822         st_kim_complete(st_gdata->kim_data);
 823         pr_debug("done %s", __func__);
 824         return err;
 825 }
 826
 827 static void st_tty_close(struct tty_struct *tty)
 828 {
 829         unsigned char i = ST_MAX;
 830         unsigned long flags = 0;
 831         struct  st_data_s *st_gdata = tty->disc_data;
 832
 833         pr_info("%s ", __func__);
 834
 835         /* TODO:
 836          * if a protocol has been registered & line discipline
 837          * un-installed for some reason - what should be done ?
 838          */
 839         spin_lock_irqsave(&st_gdata->lock, flags);
 840         for (i = ST_BT; i < ST_MAX; i++) {
 841                 if (st_gdata->list[i] != NULL)
 842                         pr_err("%d not un-registered", i);
 843                 st_gdata->list[i] = NULL;
 844         }
 845         st_gdata->protos_registered = 0;
 846         spin_unlock_irqrestore(&st_gdata->lock, flags);
 847         /*
 848          * signal to UIM via KIM that -
 849          * N_TI_WL ldisc is un-installed
 850          */
 851         st_kim_complete(st_gdata->kim_data);
 852         st_gdata->tty = NULL;
 853         /* Flush any pending characters in the driver and discipline. */
 854         tty_ldisc_flush(tty);
 855         tty_driver_flush_buffer(tty);
 856
 857         spin_lock_irqsave(&st_gdata->lock, flags);
 858         /* empty out txq and tx_waitq */
 859         skb_queue_purge(&st_gdata->txq);
 860         skb_queue_purge(&st_gdata->tx_waitq);
 861         /* reset the TTY Rx states of ST */
 862         st_gdata->rx_count = 0;
 863         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 864         kfree_skb(st_gdata->rx_skb);
 865         st_gdata->rx_skb = NULL;
 866         spin_unlock_irqrestore(&st_gdata->lock, flags);
 867
 868         pr_debug("%s: done ", __func__);
 869 }
 870
 871 static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
 872                            char *tty_flags, int count)
 873 {
 874
 875 #ifdef VERBOSE
 876         print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
 877                 16, 1, data, count, 0);
 878 #endif
 879
 880         /*
 881          * if fw download is in progress then route incoming data
 882          * to KIM for validation
 883          */
 884         st_recv(tty->disc_data, data, count);
 885         pr_debug("done %s", __func__);
 886 }
 887
 888 /* wake-up function called in from the TTY layer
 889  * inside the internal wakeup function will be called
 890  */
 891 static void st_tty_wakeup(struct tty_struct *tty)
 892 {
 893         struct  st_data_s *st_gdata = tty->disc_data;
 894         pr_debug("%s ", __func__);
 895         /* don't do an wakeup for now */
 896         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 897
 898         /* call our internal wakeup */
 899         st_tx_wakeup((void *)st_gdata);
 900 }
 901
 902 static void st_tty_flush_buffer(struct tty_struct *tty)
 903 {
 904         struct  st_data_s *st_gdata = tty->disc_data;
 905         pr_debug("%s ", __func__);
 906
 907         kfree_skb(st_gdata->tx_skb);
 908         st_gdata->tx_skb = NULL;
 909
 910         tty->ops->flush_buffer(tty);
 911         return;
 912 }
 913
 914 /********************************************************************/
 915 int st_core_init(struct st_data_s **core_data)
 916 {
 917         struct st_data_s *st_gdata;
 918         long err;
 919         static struct tty_ldisc_ops *st_ldisc_ops;
 920
 921         /* populate and register to TTY line discipline */
 922         st_ldisc_ops = kzalloc(sizeof(*st_ldisc_ops), GFP_KERNEL);
 923         if (!st_ldisc_ops) {
 924                 pr_err("no mem to allocate");
 925                 return -ENOMEM;
 926         }
 927
 928         st_ldisc_ops->magic = TTY_LDISC_MAGIC;
 929         st_ldisc_ops->name = "n_st";    /*"n_hci"; */
 930         st_ldisc_ops->open = st_tty_open;
 931         st_ldisc_ops->close = st_tty_close;
 932         st_ldisc_ops->receive_buf = st_tty_receive;
 933         st_ldisc_ops->write_wakeup = st_tty_wakeup;
 934         st_ldisc_ops->flush_buffer = st_tty_flush_buffer;
 935         st_ldisc_ops->owner = THIS_MODULE;
 936
 937         err = tty_register_ldisc(N_TI_WL, st_ldisc_ops);
 938         if (err) {
 939                 pr_err("error registering %d line discipline %ld",
 940                            N_TI_WL, err);
 941                 kfree(st_ldisc_ops);
 942                 return err;
 943         }
 944         pr_debug("registered n_shared line discipline");
 945
 946         st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
 947         if (!st_gdata) {
 948                 pr_err("memory allocation failed");
 949                 err = tty_unregister_ldisc(N_TI_WL);
 950                 if (err)
 951                         pr_err("unable to un-register ldisc %ld", err);
 952                 kfree(st_ldisc_ops);
 953                 err = -ENOMEM;
 954                 return err;
 955         }
 956
 957         /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
 958          * will be pushed in this queue for actual transmission.
 959          */
 960         skb_queue_head_init(&st_gdata->txq);
 961         skb_queue_head_init(&st_gdata->tx_waitq);
 962
 963         /* Locking used in st_int_enqueue() to avoid multiple execution */
 964         spin_lock_init(&st_gdata->lock);
 965
 966         /* ldisc_ops ref to be only used in __exit of module */
 967         st_gdata->ldisc_ops = st_ldisc_ops;
 968
 969
 970         err = st_ll_init(st_gdata);
 971         if (err) {
 972                 pr_err("error during st_ll initialization(%ld)", err);
 973                 kfree(st_gdata);
 974                 err = tty_unregister_ldisc(N_TI_WL);
 975                 if (err)
 976                         pr_err("unable to un-register ldisc");
 977                 kfree(st_ldisc_ops);
 978                 return -1;
 979         }
 980         *core_data = st_gdata;
 981         return 0;
 982 }
 983
 984 void st_core_exit(struct st_data_s *st_gdata)
 985 {
 986         long err;
 987         /* internal module cleanup */
 988         err = st_ll_deinit(st_gdata);
 989         if (err)
 990                 pr_err("error during deinit of ST LL %ld", err);
 991         if (st_gdata != NULL) {
 992                 /* Free ST Tx Qs and skbs */
 993                 skb_queue_purge(&st_gdata->txq);
 994                 skb_queue_purge(&st_gdata->tx_waitq);
 995                 kfree_skb(st_gdata->rx_skb);
 996                 kfree_skb(st_gdata->tx_skb);
 997                 /* TTY ldisc cleanup */
 998                 err = tty_unregister_ldisc(N_TI_WL);
 999                 if (err)
1000                         pr_err("unable to un-register ldisc %ld", err);
1001                 kfree(st_gdata->ldisc_ops);
1002                 /* free the global data pointer */
1003                 kfree(st_gdata);
1004         }
1005 }