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