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
  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         int 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, int 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         /* provide contexts for callbacks from ST */
 159         hst = hci_get_drvdata(hdev);
 160
 161         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 162                 ti_st_proto[i].priv_data = hst;
 163                 ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
 164                 ti_st_proto[i].recv = st_receive;
 165                 ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
 166
 167                 /* Prepare wait-for-completion handler */
 168                 init_completion(&hst->wait_reg_completion);
 169                 /* Reset ST registration callback status flag,
 170                  * this value will be updated in
 171                  * st_reg_completion_cb()
 172                  * function whenever it called from ST driver.
 173                  */
 174                 hst->reg_status = -EINPROGRESS;
 175
 176                 err = st_register(&ti_st_proto[i]);
 177                 if (!err)
 178                         goto done;
 179
 180                 if (err != -EINPROGRESS) {
 181                         BT_ERR("st_register failed %d", err);
 182                         return err;
 183                 }
 184
 185                 /* ST is busy with either protocol
 186                  * registration or firmware download.
 187                  */
 188                 BT_DBG("waiting for registration "
 189                                 "completion signal from ST");
 190                 timeleft = wait_for_completion_timeout
 191                         (&hst->wait_reg_completion,
 192                          msecs_to_jiffies(BT_REGISTER_TIMEOUT));
 193                 if (!timeleft) {
 194                         BT_ERR("Timeout(%d sec),didn't get reg "
 195                                         "completion signal from ST",
 196                                         BT_REGISTER_TIMEOUT / 1000);
 197                         return -ETIMEDOUT;
 198                 }
 199
 200                 /* Is ST registration callback
 201                  * called with ERROR status? */
 202                 if (hst->reg_status != 0) {
 203                         BT_ERR("ST registration completed with invalid "
 204                                         "status %d", hst->reg_status);
 205                         return -EAGAIN;
 206                 }
 207
 208 done:
 209                 hst->st_write = ti_st_proto[i].write;
 210                 if (!hst->st_write) {
 211                         BT_ERR("undefined ST write function");
 212                         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 213                                 /* Undo registration with ST */
 214                                 err = st_unregister(&ti_st_proto[i]);
 215                                 if (err)
 216                                         BT_ERR("st_unregister() failed with "
 217                                                         "error %d", err);
 218                                 hst->st_write = NULL;
 219                         }
 220                         return -EIO;
 221                 }
 222         }
 223         return 0;
 224 }
 225
 226 /* Close device */
 227 static int ti_st_close(struct hci_dev *hdev)
 228 {
 229         int err, i;
 230         struct ti_st *hst = hci_get_drvdata(hdev);
 231
 232         for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
 233                 err = st_unregister(&ti_st_proto[i]);
 234                 if (err)
 235                         BT_ERR("st_unregister(%d) failed with error %d",
 236                                         ti_st_proto[i].chnl_id, err);
 237         }
 238
 239         hst->st_write = NULL;
 240
 241         return err;
 242 }
 243
 244 static int ti_st_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 245 {
 246         struct ti_st *hst;
 247         long len;
 248
 249         hst = hci_get_drvdata(hdev);
 250
 251         /* Prepend skb with frame type */
 252         memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
 253
 254         BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
 255                skb->len);
 256
 257         /* Insert skb to shared transport layer's transmit queue.
 258          * Freeing skb memory is taken care in shared transport layer,
 259          * so don't free skb memory here.
 260          */
 261         len = hst->st_write(skb);
 262         if (len < 0) {
 263                 kfree_skb(skb);
 264                 BT_ERR("ST write failed (%ld)", len);
 265                 /* Try Again, would only fail if UART has gone bad */
 266                 return -EAGAIN;
 267         }
 268
 269         /* ST accepted our skb. So, Go ahead and do rest */
 270         hdev->stat.byte_tx += len;
 271         ti_st_tx_complete(hst, hci_skb_pkt_type(skb));
 272
 273         return 0;
 274 }
 275
 276 static int bt_ti_probe(struct platform_device *pdev)
 277 {
 278         static struct ti_st *hst;
 279         struct hci_dev *hdev;
 280         int err;
 281
 282         hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
 283         if (!hst)
 284                 return -ENOMEM;
 285
 286         /* Expose "hciX" device to user space */
 287         hdev = hci_alloc_dev();
 288         if (!hdev)
 289                 return -ENOMEM;
 290
 291         BT_DBG("hdev %p", hdev);
 292
 293         hst->hdev = hdev;
 294         hdev->bus = HCI_UART;
 295         hci_set_drvdata(hdev, hst);
 296         hdev->open = ti_st_open;
 297         hdev->close = ti_st_close;
 298         hdev->flush = NULL;
 299         hdev->send = ti_st_send_frame;
 300
 301         err = hci_register_dev(hdev);
 302         if (err < 0) {
 303                 BT_ERR("Can't register HCI device error %d", err);
 304                 hci_free_dev(hdev);
 305                 return err;
 306         }
 307
 308         BT_DBG("HCI device registered (hdev %p)", hdev);
 309
 310         dev_set_drvdata(&pdev->dev, hst);
 311         return err;
 312 }
 313
 314 static int bt_ti_remove(struct platform_device *pdev)
 315 {
 316         struct hci_dev *hdev;
 317         struct ti_st *hst = dev_get_drvdata(&pdev->dev);
 318
 319         if (!hst)
 320                 return -EFAULT;
 321
 322         BT_DBG("%s", hst->hdev->name);
 323
 324         hdev = hst->hdev;
 325         ti_st_close(hdev);
 326         hci_unregister_dev(hdev);
 327
 328         hci_free_dev(hdev);
 329
 330         dev_set_drvdata(&pdev->dev, NULL);
 331         return 0;
 332 }
 333
 334 static struct platform_driver btwilink_driver = {
 335         .probe = bt_ti_probe,
 336         .remove = bt_ti_remove,
 337         .driver = {
 338                 .name = "btwilink",
 339         },
 340 };
 341
 342 module_platform_driver(btwilink_driver);
 343
 344 /* ------ Module Info ------ */
 345
 346 MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
 347 MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
 348 MODULE_VERSION(VERSION);
 349 MODULE_LICENSE("GPL");