drivers/bluetooth/btwilink.c

   1 /*
   2  *  Texas Instrument's Bluetooth Driver For Shared Transport.
   3  *
   4  *  Bluetooth Driver acts as interface between HCI core and
   5  *  TI Shared Transport Layer.
   6  *
   7  *  Copyright (C) 2009-2010 Texas Instruments
   8  *  Author: Raja Mani <raja_mani@ti.com>
   9  *      Pavan Savoy <pavan_savoy@ti.com>
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2 as
  13  *  published by the Free Software Foundation.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  */
  25 #define DEBUG
  26 #include <linux/platform_device.h>
  27 #include <net/bluetooth/bluetooth.h>
  28 #include <net/bluetooth/hci_core.h>
  29 #include <net/bluetooth/hci.h>
  30
  31 #include <linux/ti_wilink_st.h>
  32
  33 /* Bluetooth Driver Version */
  34 #define VERSION               "1.0"
  35 #define MAX_BT_CHNL_IDS         3
  36
  37 /* Number of seconds to wait for registration completion
  38  * when ST returns PENDING status.
  39  */
  40 #define BT_REGISTER_TIMEOUT   6000      /* 6 sec */
  41
  42 /**
  43  * struct ti_st - driver operation structure
  44  * @hdev: hci device pointer which binds to bt driver
  45  * @reg_status: ST registration callback status
  46  * @st_write: write function provided by the ST driver
  47  *      to be used by the driver during send_frame.
  48  * @wait_reg_completion - completion sync between ti_st_open
  49  *      and st_reg_completion_cb.
  50  */
  51 struct ti_st {
  52         struct hci_dev *hdev;
  53         char reg_status;
  54         long (*st_write) (struct sk_buff *);
  55         struct completion wait_reg_completion;
  56 };
  57
  58 /* Increments HCI counters based on pocket ID (cmd,acl,sco) */
  59 static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
  60 {
  61         struct hci_dev *hdev = hst->hdev;
  62
  63         /* Update HCI stat counters */
  64         switch (pkt_type) {
  65         case HCI_COMMAND_PKT:
  66                 hdev->stat.cmd_tx++;
  67                 break;
  68
  69         case HCI_ACLDATA_PKT:
  70                 hdev->stat.acl_tx++;
  71                 break;
  72
  73         case HCI_SCODATA_PKT:
  74                 hdev->stat.sco_tx++;
  75                 break;
  76         }
  77 }
  78
  79 /* ------- Interfaces to Shared Transport ------ */
  80
  81 /* Called by ST layer to indicate protocol registration completion
  82  * status.ti_st_open() function will wait for signal from this
  83  * API when st_register() function returns ST_PENDING.
  84  */
  85 static void st_reg_completion_cb(void *priv_data, char data)
  86 {
  87         struct ti_st *lhst = priv_data;
  88
  89         /* Save registration status for use in ti_st_open() */
  90         lhst->reg_status = data;
  91         /* complete the wait in ti_st_open() */
  92         complete(&lhst->wait_reg_completion);
  93 }
  94
  95 /* Called by Shared Transport layer when receive data is
  96  * available */
  97 static long st_receive(void *priv_data, struct sk_buff *skb)
  98 {
  99         struct ti_st *lhst = priv_data;
 100         int err;
 101
 102         if (!skb)
 103                 return -EFAULT;
 104
 105         if (!lhst) {
 106                 kfree_skb(skb);
 107                 return -EFAULT;
 108         }
 109
 110         skb->dev = (void *) lhst->hdev;
 111
 112         /* Forward skb to HCI core layer */
 113         err = hci_recv_frame(skb);
 114         if (err < 0) {
 115                 BT_ERR("Unable to push skb to HCI core(%d)", err);
 116                 return err;
 117         }
 118
 119         lhst->hdev->stat.byte_rx += skb->len;
 120
 121         return 0;
 122 }
 123
 124 /* ------- Interfaces to HCI layer ------ */
 125 /* protocol structure registered with shared transport */
 126 static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
 127         {
 128                 .chnl_id = HCI_ACLDATA_PKT, /* ACL */
 129                 .hdr_len = sizeof(struct hci_acl_hdr),
 130                 .offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
 131                 .len_size = 2,  /* sizeof(dlen) in struct hci_acl_hdr */
 132                 .reserve = 8,
 133         },
 134         {
 135                 .chnl_id = HCI_SCODATA_PKT, /* SCO */
 136                 .hdr_len = sizeof(struct hci_sco_hdr),
 137                 .offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
 138                 .len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
 139                 .reserve = 8,
 140         },
 141         {
 142                 .chnl_id = HCI_EVENT_PKT, /* HCI Events */
 143                 .hdr_len = sizeof(struct hci_event_hdr),
 144                 .offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
 145                 .len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
 146                 .reserve = 8,
 147         },
 148 };
 149
 150 /* Called from HCI core to initialize the device */
 151 static int ti_st_open(struct hci_dev *hdev)
 152 {
 153         unsigned long timeleft;
 154         struct ti_st *hst;
 155         int err, i;
 156
 157         BT_DBG("%s %p", hdev->name, hdev);
 158
 159         if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
 160                 return -EBUSY;
 161
 162         /* provide contexts for callbacks from ST */
 163         hst = hdev->driver_data;
 164
 165         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 166                 ti_st_proto[i].priv_data = hst;
 167                 ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
 168                 ti_st_proto[i].recv = st_receive;
 169                 ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
 170
 171                 /* Prepare wait-for-completion handler */
 172                 init_completion(&hst->wait_reg_completion);
 173                 /* Reset ST registration callback status flag,
 174                  * this value will be updated in
 175                  * st_reg_completion_cb()
 176                  * function whenever it called from ST driver.
 177                  */
 178                 hst->reg_status = -EINPROGRESS;
 179
 180                 err = st_register(&ti_st_proto[i]);
 181                 if (!err)
 182                         goto done;
 183
 184                 if (err != -EINPROGRESS) {
 185                         clear_bit(HCI_RUNNING, &hdev->flags);
 186                         BT_ERR("st_register failed %d", err);
 187                         return err;
 188                 }
 189
 190                 /* ST is busy with either protocol
 191                  * registration or firmware download.
 192                  */
 193                 BT_DBG("waiting for registration "
 194                                 "completion signal from ST");
 195                 timeleft = wait_for_completion_timeout
 196                         (&hst->wait_reg_completion,
 197                          msecs_to_jiffies(BT_REGISTER_TIMEOUT));
 198                 if (!timeleft) {
 199                         clear_bit(HCI_RUNNING, &hdev->flags);
 200                         BT_ERR("Timeout(%d sec),didn't get reg "
 201                                         "completion signal from ST",
 202                                         BT_REGISTER_TIMEOUT / 1000);
 203                         return -ETIMEDOUT;
 204                 }
 205
 206                 /* Is ST registration callback
 207                  * called with ERROR status? */
 208                 if (hst->reg_status != 0) {
 209                         clear_bit(HCI_RUNNING, &hdev->flags);
 210                         BT_ERR("ST registration completed with invalid "
 211                                         "status %d", hst->reg_status);
 212                         return -EAGAIN;
 213                 }
 214
 215 done:
 216                 hst->st_write = ti_st_proto[i].write;
 217                 if (!hst->st_write) {
 218                         BT_ERR("undefined ST write function");
 219                         clear_bit(HCI_RUNNING, &hdev->flags);
 220                         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 221                                 /* Undo registration with ST */
 222                                 err = st_unregister(&ti_st_proto[i]);
 223                                 if (err)
 224                                         BT_ERR("st_unregister() failed with "
 225                                                         "error %d", err);
 226                                 hst->st_write = NULL;
 227                         }
 228                         return -EIO;
 229                 }
 230         }
 231         return 0;
 232 }
 233
 234 /* Close device */
 235 static int ti_st_close(struct hci_dev *hdev)
 236 {
 237         int err, i;
 238         struct ti_st *hst = hdev->driver_data;
 239
 240         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 241                 return 0;
 242
 243         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 244                 err = st_unregister(&ti_st_proto[i]);
 245                 if (err)
 246                         BT_ERR("st_unregister(%d) failed with error %d",
 247                                         ti_st_proto[i].chnl_id, err);
 248         }
 249
 250         hst->st_write = NULL;
 251
 252         return err;
 253 }
 254
 255 static int ti_st_send_frame(struct sk_buff *skb)
 256 {
 257         struct hci_dev *hdev;
 258         struct ti_st *hst;
 259         long len;
 260
 261         hdev = (struct hci_dev *)skb->dev;
 262
 263         if (!test_bit(HCI_RUNNING, &hdev->flags))
 264                 return -EBUSY;
 265
 266         hst = hdev->driver_data;
 267
 268         /* Prepend skb with frame type */
 269         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 270
 271         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type,
 272                         skb->len);
 273
 274         /* Insert skb to shared transport layer's transmit queue.
 275          * Freeing skb memory is taken care in shared transport layer,
 276          * so don't free skb memory here.
 277          */
 278         len = hst->st_write(skb);
 279         if (len < 0) {
 280                 kfree_skb(skb);
 281                 BT_ERR("ST write failed (%ld)", len);
 282                 /* Try Again, would only fail if UART has gone bad */
 283                 return -EAGAIN;
 284         }
 285
 286         /* ST accepted our skb. So, Go ahead and do rest */
 287         hdev->stat.byte_tx += len;
 288         ti_st_tx_complete(hst, bt_cb(skb)->pkt_type);
 289
 290         return 0;
 291 }
 292
 293 static void ti_st_destruct(struct hci_dev *hdev)
 294 {
 295         BT_DBG("%s", hdev->name);
 296         /* do nothing here, since platform remove
 297          * would free the hdev->driver_data
 298          */
 299 }
 300
 301 static int bt_ti_probe(struct platform_device *pdev)
 302 {
 303         static struct ti_st *hst;
 304         struct hci_dev *hdev;
 305         int err;
 306
 307         hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL);
 308         if (!hst)
 309                 return -ENOMEM;
 310
 311         /* Expose "hciX" device to user space */
 312         hdev = hci_alloc_dev();
 313         if (!hdev) {
 314                 kfree(hst);
 315                 return -ENOMEM;
 316         }
 317
 318         BT_DBG("hdev %p", hdev);
 319
 320         hst->hdev = hdev;
 321         hdev->bus = HCI_UART;
 322         hdev->driver_data = hst;
 323         hdev->open = ti_st_open;
 324         hdev->close = ti_st_close;
 325         hdev->flush = NULL;
 326         hdev->send = ti_st_send_frame;
 327         hdev->destruct = ti_st_destruct;
 328         hdev->owner = THIS_MODULE;
 329
 330         err = hci_register_dev(hdev);
 331         if (err < 0) {
 332                 BT_ERR("Can't register HCI device error %d", err);
 333                 kfree(hst);
 334                 hci_free_dev(hdev);
 335                 return err;
 336         }
 337
 338         BT_DBG("HCI device registered (hdev %p)", hdev);
 339
 340         dev_set_drvdata(&pdev->dev, hst);
 341         return err;
 342 }
 343
 344 static int bt_ti_remove(struct platform_device *pdev)
 345 {
 346         struct hci_dev *hdev;
 347         struct ti_st *hst = dev_get_drvdata(&pdev->dev);
 348
 349         if (!hst)
 350                 return -EFAULT;
 351
 352         BT_DBG("%s", hst->hdev->name);
 353
 354         hdev = hst->hdev;
 355         ti_st_close(hdev);
 356         hci_unregister_dev(hdev);
 357
 358         hci_free_dev(hdev);
 359         kfree(hst);
 360
 361         dev_set_drvdata(&pdev->dev, NULL);
 362         return 0;
 363 }
 364
 365 static struct platform_driver btwilink_driver = {
 366         .probe = bt_ti_probe,
 367         .remove = bt_ti_remove,
 368         .driver = {
 369                 .name = "btwilink",
 370                 .owner = THIS_MODULE,
 371         },
 372 };
 373
 374 /* ------- Module Init/Exit interfaces ------ */
 375 static int __init btwilink_init(void)
 376 {
 377         BT_INFO("Bluetooth Driver for TI WiLink - Version %s", VERSION);
 378
 379         return platform_driver_register(&btwilink_driver);
 380 }
 381
 382 static void __exit btwilink_exit(void)
 383 {
 384         platform_driver_unregister(&btwilink_driver);
 385 }
 386
 387 module_init(btwilink_init);
 388 module_exit(btwilink_exit);
 389
 390 /* ------ Module Info ------ */
 391
 392 MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
 393 MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
 394 MODULE_VERSION(VERSION);
 395 MODULE_LICENSE("GPL");