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 #include <linux/seq_file.h>
  29 #include <linux/skbuff.h>
  30
  31 #include <linux/ti_wilink_st.h>
  32
  33 /* function pointer pointing to either,
  34  * st_kim_recv during registration to receive fw download responses
  35  * st_int_recv after registration to receive proto stack responses
  36  */
  37 void (*st_recv) (void*, const unsigned char*, long);
  38
  39 /********************************************************************/
  40 static void add_channel_to_table(struct st_data_s *st_gdata,
  41                 struct st_proto_s *new_proto)
  42 {
  43         pr_info("%s: id %d\n", __func__, new_proto->chnl_id);
  44         /* list now has the channel id as index itself */
  45         st_gdata->list[new_proto->chnl_id] = new_proto;
  46         st_gdata->is_registered[new_proto->chnl_id] = true;
  47 }
  48
  49 static void remove_channel_from_table(struct st_data_s *st_gdata,
  50                 struct st_proto_s *proto)
  51 {
  52         pr_info("%s: id %d\n", __func__, proto->chnl_id);
  53 /*      st_gdata->list[proto->chnl_id] = NULL; */
  54         st_gdata->is_registered[proto->chnl_id] = false;
  55 }
  56
  57 /*
  58  * called from KIM during firmware download.
  59  *
  60  * This is a wrapper function to tty->ops->write_room.
  61  * It returns number of free space available in
  62  * uart tx buffer.
  63  */
  64 int st_get_uart_wr_room(struct st_data_s *st_gdata)
  65 {
  66         struct tty_struct *tty;
  67         if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
  68                 pr_err("tty unavailable to perform write");
  69                 return -1;
  70         }
  71         tty = st_gdata->tty;
  72         return tty->ops->write_room(tty);
  73 }
  74
  75 /* can be called in from
  76  * -- KIM (during fw download)
  77  * -- ST Core (during st_write)
  78  *
  79  *  This is the internal write function - a wrapper
  80  *  to tty->ops->write
  81  */
  82 int st_int_write(struct st_data_s *st_gdata,
  83         const unsigned char *data, int count)
  84 {
  85         struct tty_struct *tty;
  86         if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
  87                 pr_err("tty unavailable to perform write");
  88                 return -EINVAL;
  89         }
  90         tty = st_gdata->tty;
  91 #ifdef VERBOSE
  92         print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE,
  93                 16, 1, data, count, 0);
  94 #endif
  95         return tty->ops->write(tty, data, count);
  96
  97 }
  98
  99 /*
 100  * push the skb received to relevant
 101  * protocol stacks
 102  */
 103 void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata)
 104 {
 105         pr_debug(" %s(prot:%d) ", __func__, chnl_id);
 106
 107         if (unlikely
 108             (st_gdata == NULL || st_gdata->rx_skb == NULL
 109              || st_gdata->is_registered[chnl_id] == false)) {
 110                 pr_err("chnl_id %d not registered, no data to send?",
 111                            chnl_id);
 112                 kfree_skb(st_gdata->rx_skb);
 113                 return;
 114         }
 115         /* this cannot fail
 116          * this shouldn't take long
 117          * - should be just skb_queue_tail for the
 118          *   protocol stack driver
 119          */
 120         if (likely(st_gdata->list[chnl_id]->recv != NULL)) {
 121                 if (unlikely
 122                         (st_gdata->list[chnl_id]->recv
 123                         (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb)
 124                              != 0)) {
 125                         pr_err(" proto stack %d's ->recv failed", chnl_id);
 126                         kfree_skb(st_gdata->rx_skb);
 127                         return;
 128                 }
 129         } else {
 130                 pr_err(" proto stack %d's ->recv null", chnl_id);
 131                 kfree_skb(st_gdata->rx_skb);
 132         }
 133         return;
 134 }
 135
 136 /**
 137  * st_reg_complete -
 138  * to call registration complete callbacks
 139  * of all protocol stack drivers
 140  * This function is being called with spin lock held, protocol drivers are
 141  * only expected to complete their waits and do nothing more than that.
 142  */
 143 void st_reg_complete(struct st_data_s *st_gdata, char err)
 144 {
 145         unsigned char i = 0;
 146         pr_info(" %s ", __func__);
 147         for (i = 0; i < ST_MAX_CHANNELS; i++) {
 148                 if (likely(st_gdata != NULL &&
 149                         st_gdata->is_registered[i] == true &&
 150                                 st_gdata->list[i]->reg_complete_cb != NULL)) {
 151                         st_gdata->list[i]->reg_complete_cb
 152                                 (st_gdata->list[i]->priv_data, err);
 153                         pr_info("protocol %d's cb sent %d\n", i, err);
 154                         if (err) { /* cleanup registered protocol */
 155                                 st_gdata->protos_registered--;
 156                                 st_gdata->is_registered[i] = false;
 157                         }
 158                 }
 159         }
 160 }
 161
 162 static inline int st_check_data_len(struct st_data_s *st_gdata,
 163         unsigned char chnl_id, int len)
 164 {
 165         int room = skb_tailroom(st_gdata->rx_skb);
 166
 167         pr_debug("len %d room %d", len, room);
 168
 169         if (!len) {
 170                 /* Received packet has only packet header and
 171                  * has zero length payload. So, ask ST CORE to
 172                  * forward the packet to protocol driver (BT/FM/GPS)
 173                  */
 174                 st_send_frame(chnl_id, st_gdata);
 175
 176         } else if (len > room) {
 177                 /* Received packet's payload length is larger.
 178                  * We can't accommodate it in created skb.
 179                  */
 180                 pr_err("Data length is too large len %d room %d", len,
 181                            room);
 182                 kfree_skb(st_gdata->rx_skb);
 183         } else {
 184                 /* Packet header has non-zero payload length and
 185                  * we have enough space in created skb. Lets read
 186                  * payload data */
 187                 st_gdata->rx_state = ST_W4_DATA;
 188                 st_gdata->rx_count = len;
 189                 return len;
 190         }
 191
 192         /* Change ST state to continue to process next
 193          * packet */
 194         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 195         st_gdata->rx_skb = NULL;
 196         st_gdata->rx_count = 0;
 197         st_gdata->rx_chnl = 0;
 198
 199         return 0;
 200 }
 201
 202 /**
 203  * st_wakeup_ack - internal function for action when wake-up ack
 204  *      received
 205  */
 206 static inline void st_wakeup_ack(struct st_data_s *st_gdata,
 207         unsigned char cmd)
 208 {
 209         struct sk_buff *waiting_skb;
 210         unsigned long flags = 0;
 211
 212         spin_lock_irqsave(&st_gdata->lock, flags);
 213         /* de-Q from waitQ and Q in txQ now that the
 214          * chip is awake
 215          */
 216         while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq)))
 217                 skb_queue_tail(&st_gdata->txq, waiting_skb);
 218
 219         /* state forwarded to ST LL */
 220         st_ll_sleep_state(st_gdata, (unsigned long)cmd);
 221         spin_unlock_irqrestore(&st_gdata->lock, flags);
 222
 223         /* wake up to send the recently copied skbs from waitQ */
 224         st_tx_wakeup(st_gdata);
 225 }
 226
 227 /**
 228  * st_int_recv - ST's internal receive function.
 229  *      Decodes received RAW data and forwards to corresponding
 230  *      client drivers (Bluetooth,FM,GPS..etc).
 231  *      This can receive various types of packets,
 232  *      HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets
 233  *      CH-8 packets from FM, CH-9 packets from GPS cores.
 234  */
 235 void st_int_recv(void *disc_data,
 236         const unsigned char *data, long count)
 237 {
 238         char *ptr;
 239         struct st_proto_s *proto;
 240         unsigned short payload_len = 0;
 241         int len = 0, type = 0;
 242         unsigned char *plen;
 243         struct st_data_s *st_gdata = (struct st_data_s *)disc_data;
 244         unsigned long flags;
 245
 246         ptr = (char *)data;
 247         /* tty_receive sent null ? */
 248         if (unlikely(ptr == NULL) || (st_gdata == NULL)) {
 249                 pr_err(" received null from TTY ");
 250                 return;
 251         }
 252
 253         pr_debug("count %ld rx_state %ld"
 254                    "rx_count %ld", count, st_gdata->rx_state,
 255                    st_gdata->rx_count);
 256
 257         spin_lock_irqsave(&st_gdata->lock, flags);
 258         /* Decode received bytes here */
 259         while (count) {
 260                 if (st_gdata->rx_count) {
 261                         len = min_t(unsigned int, st_gdata->rx_count, count);
 262                         memcpy(skb_put(st_gdata->rx_skb, len), ptr, len);
 263                         st_gdata->rx_count -= len;
 264                         count -= len;
 265                         ptr += len;
 266
 267                         if (st_gdata->rx_count)
 268                                 continue;
 269
 270                         /* Check ST RX state machine , where are we? */
 271                         switch (st_gdata->rx_state) {
 272                         /* Waiting for complete packet ? */
 273                         case ST_W4_DATA:
 274                                 pr_debug("Complete pkt received");
 275                                 /* Ask ST CORE to forward
 276                                  * the packet to protocol driver */
 277                                 st_send_frame(st_gdata->rx_chnl, st_gdata);
 278
 279                                 st_gdata->rx_state = ST_W4_PACKET_TYPE;
 280                                 st_gdata->rx_skb = NULL;
 281                                 continue;
 282                         /* parse the header to know details */
 283                         case ST_W4_HEADER:
 284                                 proto = st_gdata->list[st_gdata->rx_chnl];
 285                                 plen =
 286                                 &st_gdata->rx_skb->data
 287                                 [proto->offset_len_in_hdr];
 288                                 pr_debug("plen pointing to %x\n", *plen);
 289                                 if (proto->len_size == 1)/* 1 byte len field */
 290                                         payload_len = *(unsigned char *)plen;
 291                                 else if (proto->len_size == 2)
 292                                         payload_len =
 293                                         __le16_to_cpu(*(unsigned short *)plen);
 294                                 else
 295                                         pr_info("%s: invalid length "
 296                                         "for id %d\n",
 297                                         __func__, proto->chnl_id);
 298                                 st_check_data_len(st_gdata, proto->chnl_id,
 299                                                 payload_len);
 300                                 pr_debug("off %d, pay len %d\n",
 301                                         proto->offset_len_in_hdr, payload_len);
 302                                 continue;
 303                         }       /* end of switch rx_state */
 304                 }
 305
 306                 /* end of if rx_count */
 307                 /* Check first byte of packet and identify module
 308                  * owner (BT/FM/GPS) */
 309                 switch (*ptr) {
 310                 case LL_SLEEP_IND:
 311                 case LL_SLEEP_ACK:
 312                 case LL_WAKE_UP_IND:
 313                         pr_debug("PM packet");
 314                         /* this takes appropriate action based on
 315                          * sleep state received --
 316                          */
 317                         st_ll_sleep_state(st_gdata, *ptr);
 318                         /* if WAKEUP_IND collides copy from waitq to txq
 319                          * and assume chip awake
 320                          */
 321                         spin_unlock_irqrestore(&st_gdata->lock, flags);
 322                         if (st_ll_getstate(st_gdata) == ST_LL_AWAKE)
 323                                 st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK);
 324                         spin_lock_irqsave(&st_gdata->lock, flags);
 325
 326                         ptr++;
 327                         count--;
 328                         continue;
 329                 case LL_WAKE_UP_ACK:
 330                         pr_debug("PM packet");
 331
 332                         spin_unlock_irqrestore(&st_gdata->lock, flags);
 333                         /* wake up ack received */
 334                         st_wakeup_ack(st_gdata, *ptr);
 335                         spin_lock_irqsave(&st_gdata->lock, flags);
 336
 337                         ptr++;
 338                         count--;
 339                         continue;
 340                         /* Unknow packet? */
 341                 default:
 342                         type = *ptr;
 343                         if (st_gdata->list[type] == NULL) {
 344                                 pr_err("chip/interface misbehavior dropping"
 345                                         " frame starting with 0x%02x", type);
 346                                 goto done;
 347
 348                         }
 349                         st_gdata->rx_skb = alloc_skb(
 350                                         st_gdata->list[type]->max_frame_size,
 351                                         GFP_ATOMIC);
 352                         skb_reserve(st_gdata->rx_skb,
 353                                         st_gdata->list[type]->reserve);
 354                         /* next 2 required for BT only */
 355                         st_gdata->rx_skb->cb[0] = type; /*pkt_type*/
 356                         st_gdata->rx_skb->cb[1] = 0; /*incoming*/
 357                         st_gdata->rx_chnl = *ptr;
 358                         st_gdata->rx_state = ST_W4_HEADER;
 359                         st_gdata->rx_count = st_gdata->list[type]->hdr_len;
 360                         pr_debug("rx_count %ld\n", st_gdata->rx_count);
 361                 };
 362                 ptr++;
 363                 count--;
 364         }
 365 done:
 366         spin_unlock_irqrestore(&st_gdata->lock, flags);
 367         pr_debug("done %s", __func__);
 368         return;
 369 }
 370
 371 /**
 372  * st_int_dequeue - internal de-Q function.
 373  *      If the previous data set was not written
 374  *      completely, return that skb which has the pending data.
 375  *      In normal cases, return top of txq.
 376  */
 377 struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata)
 378 {
 379         struct sk_buff *returning_skb;
 380
 381         pr_debug("%s", __func__);
 382         if (st_gdata->tx_skb != NULL) {
 383                 returning_skb = st_gdata->tx_skb;
 384                 st_gdata->tx_skb = NULL;
 385                 return returning_skb;
 386         }
 387         return skb_dequeue(&st_gdata->txq);
 388 }
 389
 390 /**
 391  * st_int_enqueue - internal Q-ing function.
 392  *      Will either Q the skb to txq or the tx_waitq
 393  *      depending on the ST LL state.
 394  *      If the chip is asleep, then Q it onto waitq and
 395  *      wakeup the chip.
 396  *      txq and waitq needs protection since the other contexts
 397  *      may be sending data, waking up chip.
 398  */
 399 void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb)
 400 {
 401         unsigned long flags = 0;
 402
 403         pr_debug("%s", __func__);
 404         spin_lock_irqsave(&st_gdata->lock, flags);
 405
 406         switch (st_ll_getstate(st_gdata)) {
 407         case ST_LL_AWAKE:
 408                 pr_debug("ST LL is AWAKE, sending normally");
 409                 skb_queue_tail(&st_gdata->txq, skb);
 410                 break;
 411         case ST_LL_ASLEEP_TO_AWAKE:
 412                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 413                 break;
 414         case ST_LL_AWAKE_TO_ASLEEP:
 415                 pr_err("ST LL is illegal state(%ld),"
 416                            "purging received skb.", st_ll_getstate(st_gdata));
 417                 kfree_skb(skb);
 418                 break;
 419         case ST_LL_ASLEEP:
 420                 skb_queue_tail(&st_gdata->tx_waitq, skb);
 421                 st_ll_wakeup(st_gdata);
 422                 break;
 423         default:
 424                 pr_err("ST LL is illegal state(%ld),"
 425                            "purging received skb.", st_ll_getstate(st_gdata));
 426                 kfree_skb(skb);
 427                 break;
 428         }
 429
 430         spin_unlock_irqrestore(&st_gdata->lock, flags);
 431         pr_debug("done %s", __func__);
 432         return;
 433 }
 434
 435 /*
 436  * internal wakeup function
 437  * called from either
 438  * - TTY layer when write's finished
 439  * - st_write (in context of the protocol stack)
 440  */
 441 void st_tx_wakeup(struct st_data_s *st_data)
 442 {
 443         struct sk_buff *skb;
 444         unsigned long flags;    /* for irq save flags */
 445         pr_debug("%s", __func__);
 446         /* check for sending & set flag sending here */
 447         if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) {
 448                 pr_debug("ST already sending");
 449                 /* keep sending */
 450                 set_bit(ST_TX_WAKEUP, &st_data->tx_state);
 451                 return;
 452                 /* TX_WAKEUP will be checked in another
 453                  * context
 454                  */
 455         }
 456         do {                    /* come back if st_tx_wakeup is set */
 457                 /* woke-up to write */
 458                 clear_bit(ST_TX_WAKEUP, &st_data->tx_state);
 459                 while ((skb = st_int_dequeue(st_data))) {
 460                         int len;
 461                         spin_lock_irqsave(&st_data->lock, flags);
 462                         /* enable wake-up from TTY */
 463                         set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags);
 464                         len = st_int_write(st_data, skb->data, skb->len);
 465                         skb_pull(skb, len);
 466                         /* if skb->len = len as expected, skb->len=0 */
 467                         if (skb->len) {
 468                                 /* would be the next skb to be sent */
 469                                 st_data->tx_skb = skb;
 470                                 spin_unlock_irqrestore(&st_data->lock, flags);
 471                                 break;
 472                         }
 473                         kfree_skb(skb);
 474                         spin_unlock_irqrestore(&st_data->lock, flags);
 475                 }
 476                 /* if wake-up is set in another context- restart sending */
 477         } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state));
 478
 479         /* clear flag sending */
 480         clear_bit(ST_TX_SENDING, &st_data->tx_state);
 481 }
 482
 483 /********************************************************************/
 484 /* functions called from ST KIM
 485 */
 486 void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf)
 487 {
 488         seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n",
 489                         st_gdata->protos_registered,
 490                         st_gdata->is_registered[0x04] == true ? 'R' : 'U',
 491                         st_gdata->is_registered[0x08] == true ? 'R' : 'U',
 492                         st_gdata->is_registered[0x09] == true ? 'R' : 'U');
 493 }
 494
 495 /********************************************************************/
 496 /*
 497  * functions called from protocol stack drivers
 498  * to be EXPORT-ed
 499  */
 500 long st_register(struct st_proto_s *new_proto)
 501 {
 502         struct st_data_s        *st_gdata;
 503         long err = 0;
 504         unsigned long flags = 0;
 505
 506         st_kim_ref(&st_gdata, 0);
 507         pr_info("%s(%d) ", __func__, new_proto->chnl_id);
 508         if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL
 509             || new_proto->reg_complete_cb == NULL) {
 510                 pr_err("gdata/new_proto/recv or reg_complete_cb not ready");
 511                 return -EINVAL;
 512         }
 513
 514         if (new_proto->chnl_id >= ST_MAX_CHANNELS) {
 515                 pr_err("chnl_id %d not supported", new_proto->chnl_id);
 516                 return -EPROTONOSUPPORT;
 517         }
 518
 519         if (st_gdata->is_registered[new_proto->chnl_id] == true) {
 520                 pr_err("chnl_id %d already registered", new_proto->chnl_id);
 521                 return -EALREADY;
 522         }
 523
 524         /* can be from process context only */
 525         spin_lock_irqsave(&st_gdata->lock, flags);
 526
 527         if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) {
 528                 pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id);
 529                 /* fw download in progress */
 530
 531                 add_channel_to_table(st_gdata, new_proto);
 532                 st_gdata->protos_registered++;
 533                 new_proto->write = st_write;
 534
 535                 set_bit(ST_REG_PENDING, &st_gdata->st_state);
 536                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 537                 return -EINPROGRESS;
 538         } else if (st_gdata->protos_registered == ST_EMPTY) {
 539                 pr_info(" chnl_id list empty :%d ", new_proto->chnl_id);
 540                 set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 541                 st_recv = st_kim_recv;
 542
 543                 /* enable the ST LL - to set default chip state */
 544                 st_ll_enable(st_gdata);
 545
 546                 /* release lock previously held - re-locked below */
 547                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 548
 549                 /* this may take a while to complete
 550                  * since it involves BT fw download
 551                  */
 552                 err = st_kim_start(st_gdata->kim_data);
 553                 if (err != 0) {
 554                         clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 555                         if ((st_gdata->protos_registered != ST_EMPTY) &&
 556                             (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 557                                 pr_err(" KIM failure complete callback ");
 558                                 st_reg_complete(st_gdata, err);
 559                                 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
 560                         }
 561                         return -EINVAL;
 562                 }
 563
 564                 spin_lock_irqsave(&st_gdata->lock, flags);
 565
 566                 clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state);
 567                 st_recv = st_int_recv;
 568
 569                 /* this is where all pending registration
 570                  * are signalled to be complete by calling callback functions
 571                  */
 572                 if ((st_gdata->protos_registered != ST_EMPTY) &&
 573                     (test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 574                         pr_debug(" call reg complete callback ");
 575                         st_reg_complete(st_gdata, 0);
 576                 }
 577                 clear_bit(ST_REG_PENDING, &st_gdata->st_state);
 578
 579                 /* check for already registered once more,
 580                  * since the above check is old
 581                  */
 582                 if (st_gdata->is_registered[new_proto->chnl_id] == true) {
 583                         pr_err(" proto %d already registered ",
 584                                    new_proto->chnl_id);
 585                         spin_unlock_irqrestore(&st_gdata->lock, flags);
 586                         return -EALREADY;
 587                 }
 588
 589                 add_channel_to_table(st_gdata, new_proto);
 590                 st_gdata->protos_registered++;
 591                 new_proto->write = st_write;
 592                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 593                 return err;
 594         }
 595         /* if fw is already downloaded & new stack registers protocol */
 596         else {
 597                 add_channel_to_table(st_gdata, new_proto);
 598                 st_gdata->protos_registered++;
 599                 new_proto->write = st_write;
 600
 601                 /* lock already held before entering else */
 602                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 603                 return err;
 604         }
 605         pr_debug("done %s(%d) ", __func__, new_proto->chnl_id);
 606 }
 607 EXPORT_SYMBOL_GPL(st_register);
 608
 609 /* to unregister a protocol -
 610  * to be called from protocol stack driver
 611  */
 612 long st_unregister(struct st_proto_s *proto)
 613 {
 614         long err = 0;
 615         unsigned long flags = 0;
 616         struct st_data_s        *st_gdata;
 617
 618         pr_debug("%s: %d ", __func__, proto->chnl_id);
 619
 620         st_kim_ref(&st_gdata, 0);
 621         if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) {
 622                 pr_err(" chnl_id %d not supported", proto->chnl_id);
 623                 return -EPROTONOSUPPORT;
 624         }
 625
 626         spin_lock_irqsave(&st_gdata->lock, flags);
 627
 628         if (st_gdata->is_registered[proto->chnl_id] == false) {
 629                 pr_err(" chnl_id %d not registered", proto->chnl_id);
 630                 spin_unlock_irqrestore(&st_gdata->lock, flags);
 631                 return -EPROTONOSUPPORT;
 632         }
 633
 634         st_gdata->protos_registered--;
 635         remove_channel_from_table(st_gdata, proto);
 636         spin_unlock_irqrestore(&st_gdata->lock, flags);
 637
 638         /* paranoid check */
 639         if (st_gdata->protos_registered < ST_EMPTY)
 640                 st_gdata->protos_registered = ST_EMPTY;
 641
 642         if ((st_gdata->protos_registered == ST_EMPTY) &&
 643             (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) {
 644                 pr_info(" all chnl_ids unregistered ");
 645
 646                 /* stop traffic on tty */
 647                 if (st_gdata->tty) {
 648                         tty_ldisc_flush(st_gdata->tty);
 649                         stop_tty(st_gdata->tty);
 650                 }
 651
 652                 /* all chnl_ids now unregistered */
 653                 st_kim_stop(st_gdata->kim_data);
 654                 /* disable ST LL */
 655                 st_ll_disable(st_gdata);
 656         }
 657         return err;
 658 }
 659
 660 /*
 661  * called in protocol stack drivers
 662  * via the write function pointer
 663  */
 664 long st_write(struct sk_buff *skb)
 665 {
 666         struct st_data_s *st_gdata;
 667         long len;
 668
 669         st_kim_ref(&st_gdata, 0);
 670         if (unlikely(skb == NULL || st_gdata == NULL
 671                 || st_gdata->tty == NULL)) {
 672                 pr_err("data/tty unavailable to perform write");
 673                 return -EINVAL;
 674         }
 675
 676         pr_debug("%d to be written", skb->len);
 677         len = skb->len;
 678
 679         /* st_ll to decide where to enqueue the skb */
 680         st_int_enqueue(st_gdata, skb);
 681         /* wake up */
 682         st_tx_wakeup(st_gdata);
 683
 684         /* return number of bytes written */
 685         return len;
 686 }
 687
 688 /* for protocols making use of shared transport */
 689 EXPORT_SYMBOL_GPL(st_unregister);
 690
 691 /********************************************************************/
 692 /*
 693  * functions called from TTY layer
 694  */
 695 static int st_tty_open(struct tty_struct *tty)
 696 {
 697         int err = 0;
 698         struct st_data_s *st_gdata;
 699         pr_info("%s ", __func__);
 700
 701         st_kim_ref(&st_gdata, 0);
 702         st_gdata->tty = tty;
 703         tty->disc_data = st_gdata;
 704
 705         /* don't do an wakeup for now */
 706         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 707
 708         /* mem already allocated
 709          */
 710         tty->receive_room = 65536;
 711         /* Flush any pending characters in the driver and discipline. */
 712         tty_ldisc_flush(tty);
 713         tty_driver_flush_buffer(tty);
 714         /*
 715          * signal to UIM via KIM that -
 716          * installation of N_TI_WL ldisc is complete
 717          */
 718         st_kim_complete(st_gdata->kim_data);
 719         pr_debug("done %s", __func__);
 720         return err;
 721 }
 722
 723 static void st_tty_close(struct tty_struct *tty)
 724 {
 725         unsigned char i = ST_MAX_CHANNELS;
 726         unsigned long flags = 0;
 727         struct  st_data_s *st_gdata = tty->disc_data;
 728
 729         pr_info("%s ", __func__);
 730
 731         /* TODO:
 732          * if a protocol has been registered & line discipline
 733          * un-installed for some reason - what should be done ?
 734          */
 735         spin_lock_irqsave(&st_gdata->lock, flags);
 736         for (i = ST_BT; i < ST_MAX_CHANNELS; i++) {
 737                 if (st_gdata->is_registered[i] == true)
 738                         pr_err("%d not un-registered", i);
 739                 st_gdata->list[i] = NULL;
 740                 st_gdata->is_registered[i] = false;
 741         }
 742         st_gdata->protos_registered = 0;
 743         spin_unlock_irqrestore(&st_gdata->lock, flags);
 744         /*
 745          * signal to UIM via KIM that -
 746          * N_TI_WL ldisc is un-installed
 747          */
 748         st_kim_complete(st_gdata->kim_data);
 749         st_gdata->tty = NULL;
 750         /* Flush any pending characters in the driver and discipline. */
 751         tty_ldisc_flush(tty);
 752         tty_driver_flush_buffer(tty);
 753
 754         spin_lock_irqsave(&st_gdata->lock, flags);
 755         /* empty out txq and tx_waitq */
 756         skb_queue_purge(&st_gdata->txq);
 757         skb_queue_purge(&st_gdata->tx_waitq);
 758         /* reset the TTY Rx states of ST */
 759         st_gdata->rx_count = 0;
 760         st_gdata->rx_state = ST_W4_PACKET_TYPE;
 761         kfree_skb(st_gdata->rx_skb);
 762         st_gdata->rx_skb = NULL;
 763         spin_unlock_irqrestore(&st_gdata->lock, flags);
 764
 765         pr_debug("%s: done ", __func__);
 766 }
 767
 768 static void st_tty_receive(struct tty_struct *tty, const unsigned char *data,
 769                            char *tty_flags, int count)
 770 {
 771 #ifdef VERBOSE
 772         print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE,
 773                 16, 1, data, count, 0);
 774 #endif
 775
 776         /*
 777          * if fw download is in progress then route incoming data
 778          * to KIM for validation
 779          */
 780         st_recv(tty->disc_data, data, count);
 781         pr_debug("done %s", __func__);
 782 }
 783
 784 /* wake-up function called in from the TTY layer
 785  * inside the internal wakeup function will be called
 786  */
 787 static void st_tty_wakeup(struct tty_struct *tty)
 788 {
 789         struct  st_data_s *st_gdata = tty->disc_data;
 790         pr_debug("%s ", __func__);
 791         /* don't do an wakeup for now */
 792         clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 793
 794         /* call our internal wakeup */
 795         st_tx_wakeup((void *)st_gdata);
 796 }
 797
 798 static void st_tty_flush_buffer(struct tty_struct *tty)
 799 {
 800         struct  st_data_s *st_gdata = tty->disc_data;
 801         pr_debug("%s ", __func__);
 802
 803         kfree_skb(st_gdata->tx_skb);
 804         st_gdata->tx_skb = NULL;
 805
 806         tty->ops->flush_buffer(tty);
 807         return;
 808 }
 809
 810 static struct tty_ldisc_ops st_ldisc_ops = {
 811         .magic = TTY_LDISC_MAGIC,
 812         .name = "n_st",
 813         .open = st_tty_open,
 814         .close = st_tty_close,
 815         .receive_buf = st_tty_receive,
 816         .write_wakeup = st_tty_wakeup,
 817         .flush_buffer = st_tty_flush_buffer,
 818         .owner = THIS_MODULE
 819 };
 820
 821 /********************************************************************/
 822 int st_core_init(struct st_data_s **core_data)
 823 {
 824         struct st_data_s *st_gdata;
 825         long err;
 826
 827         err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops);
 828         if (err) {
 829                 pr_err("error registering %d line discipline %ld",
 830                            N_TI_WL, err);
 831                 return err;
 832         }
 833         pr_debug("registered n_shared line discipline");
 834
 835         st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL);
 836         if (!st_gdata) {
 837                 pr_err("memory allocation failed");
 838                 err = tty_unregister_ldisc(N_TI_WL);
 839                 if (err)
 840                         pr_err("unable to un-register ldisc %ld", err);
 841                 err = -ENOMEM;
 842                 return err;
 843         }
 844
 845         /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's
 846          * will be pushed in this queue for actual transmission.
 847          */
 848         skb_queue_head_init(&st_gdata->txq);
 849         skb_queue_head_init(&st_gdata->tx_waitq);
 850
 851         /* Locking used in st_int_enqueue() to avoid multiple execution */
 852         spin_lock_init(&st_gdata->lock);
 853
 854         err = st_ll_init(st_gdata);
 855         if (err) {
 856                 pr_err("error during st_ll initialization(%ld)", err);
 857                 kfree(st_gdata);
 858                 err = tty_unregister_ldisc(N_TI_WL);
 859                 if (err)
 860                         pr_err("unable to un-register ldisc");
 861                 return err;
 862         }
 863         *core_data = st_gdata;
 864         return 0;
 865 }
 866
 867 void st_core_exit(struct st_data_s *st_gdata)
 868 {
 869         long err;
 870         /* internal module cleanup */
 871         err = st_ll_deinit(st_gdata);
 872         if (err)
 873                 pr_err("error during deinit of ST LL %ld", err);
 874
 875         if (st_gdata != NULL) {
 876                 /* Free ST Tx Qs and skbs */
 877                 skb_queue_purge(&st_gdata->txq);
 878                 skb_queue_purge(&st_gdata->tx_waitq);
 879                 kfree_skb(st_gdata->rx_skb);
 880                 kfree_skb(st_gdata->tx_skb);
 881                 /* TTY ldisc cleanup */
 882                 err = tty_unregister_ldisc(N_TI_WL);
 883                 if (err)
 884                         pr_err("unable to un-register ldisc %ld", err);
 885                 /* free the global data pointer */
 886                 kfree(st_gdata);
 887         }
 888 }
 889
 890