drivers/staging/ti-st/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
  30 #include <linux/ti_wilink_st.h>
  31
  32 /* Bluetooth Driver Version */
  33 #define VERSION               "1.0"
  34
  35 /* Number of seconds to wait for registration completion
  36  * when ST returns PENDING status.
  37  */
  38 #define BT_REGISTER_TIMEOUT   6000      /* 6 sec */
  39
  40 /**
  41  * struct ti_st - driver operation structure
  42  * @hdev: hci device pointer which binds to bt driver
  43  * @reg_status: ST registration callback status
  44  * @st_write: write function provided by the ST driver
  45  *      to be used by the driver during send_frame.
  46  * @wait_reg_completion - completion sync between ti_st_open
  47  *      and ti_st_registration_completion_cb.
  48  */
  49 struct ti_st {
  50         struct hci_dev *hdev;
  51         char reg_status;
  52         long (*st_write) (struct sk_buff *);
  53         struct completion wait_reg_completion;
  54 };
  55
  56 /* Increments HCI counters based on pocket ID (cmd,acl,sco) */
  57 static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
  58 {
  59         struct hci_dev *hdev = hst->hdev;
  60
  61         /* Update HCI stat counters */
  62         switch (pkt_type) {
  63         case HCI_COMMAND_PKT:
  64                 hdev->stat.cmd_tx++;
  65                 break;
  66
  67         case HCI_ACLDATA_PKT:
  68                 hdev->stat.acl_tx++;
  69                 break;
  70
  71         case HCI_SCODATA_PKT:
  72                 hdev->stat.sco_tx++;
  73                 break;
  74         }
  75 }
  76
  77 /* ------- Interfaces to Shared Transport ------ */
  78
  79 /* Called by ST layer to indicate protocol registration completion
  80  * status.ti_st_open() function will wait for signal from this
  81  * API when st_register() function returns ST_PENDING.
  82  */
  83 static void st_registration_completion_cb(void *priv_data, char data)
  84 {
  85         struct ti_st *lhst = priv_data;
  86
  87         /* Save registration status for use in ti_st_open() */
  88         lhst->reg_status = data;
  89         /* complete the wait in ti_st_open() */
  90         complete(&lhst->wait_reg_completion);
  91 }
  92
  93 /* Called by Shared Transport layer when receive data is
  94  * available */
  95 static long st_receive(void *priv_data, struct sk_buff *skb)
  96 {
  97         struct ti_st *lhst = priv_data;
  98         int err;
  99
 100         if (!skb)
 101                 return -EFAULT;
 102
 103         if (!lhst) {
 104                 kfree_skb(skb);
 105                 return -EFAULT;
 106         }
 107
 108         skb->dev = (void *) lhst->hdev;
 109
 110         /* Forward skb to HCI core layer */
 111         err = hci_recv_frame(skb);
 112         if (err < 0) {
 113                 BT_ERR("Unable to push skb to HCI core(%d)", err);
 114                 return err;
 115         }
 116
 117         lhst->hdev->stat.byte_rx += skb->len;
 118
 119         return 0;
 120 }
 121
 122 /* ------- Interfaces to HCI layer ------ */
 123 /* protocol structure registered with shared transport */
 124 static struct st_proto_s ti_st_proto = {
 125         .type = ST_BT,
 126         .recv = st_receive,
 127         .reg_complete_cb = st_registration_completion_cb,
 128 };
 129
 130 /* Called from HCI core to initialize the device */
 131 static int ti_st_open(struct hci_dev *hdev)
 132 {
 133         unsigned long timeleft;
 134         struct ti_st *hst;
 135         int err;
 136
 137         BT_DBG("%s %p", hdev->name, hdev);
 138         if (test_and_set_bit(HCI_RUNNING, &hdev->flags)) {
 139                 BT_ERR("btwilink already opened");
 140                 return -EBUSY;
 141         }
 142
 143         /* provide contexts for callbacks from ST */
 144         hst = hdev->driver_data;
 145         ti_st_proto.priv_data = hst;
 146
 147         err = st_register(&ti_st_proto);
 148         if (err == -EINPROGRESS) {
 149                 /* ST is busy with either protocol registration or firmware
 150                  * download.
 151                  */
 152                 /* Prepare wait-for-completion handler data structures.
 153                  */
 154                 init_completion(&hst->wait_reg_completion);
 155
 156                 /* Reset ST registration callback status flag , this value
 157                  * will be updated in ti_st_registration_completion_cb()
 158                  * function whenever it called from ST driver.
 159                  */
 160                 hst->reg_status = -EINPROGRESS;
 161
 162                 BT_DBG("waiting for registration completion signal from ST");
 163                 timeleft = wait_for_completion_timeout
 164                         (&hst->wait_reg_completion,
 165                          msecs_to_jiffies(BT_REGISTER_TIMEOUT));
 166                 if (!timeleft) {
 167                         clear_bit(HCI_RUNNING, &hdev->flags);
 168                         BT_ERR("Timeout(%d sec),didn't get reg "
 169                                         "completion signal from ST",
 170                                         BT_REGISTER_TIMEOUT / 1000);
 171                         return -ETIMEDOUT;
 172                 }
 173
 174                 /* Is ST registration callback called with ERROR status? */
 175                 if (hst->reg_status != 0) {
 176                         clear_bit(HCI_RUNNING, &hdev->flags);
 177                         BT_ERR("ST registration completed with invalid "
 178                                         "status %d", hst->reg_status);
 179                         return -EAGAIN;
 180                 }
 181                 err = 0;
 182         } else if (err != 0) {
 183                 clear_bit(HCI_RUNNING, &hdev->flags);
 184                 BT_ERR("st_register failed %d", err);
 185                 return err;
 186         }
 187
 188         /* ti_st_proto.write is filled up by the underlying shared
 189          * transport driver upon registration
 190          */
 191         hst->st_write = ti_st_proto.write;
 192         if (!hst->st_write) {
 193                 BT_ERR("undefined ST write function");
 194                 clear_bit(HCI_RUNNING, &hdev->flags);
 195
 196                 /* Undo registration with ST */
 197                 err = st_unregister(ST_BT);
 198                 if (err)
 199                         BT_ERR("st_unregister() failed with error %d", err);
 200
 201                 hst->st_write = NULL;
 202                 return err;
 203         }
 204
 205         return err;
 206 }
 207
 208 /* Close device */
 209 static int ti_st_close(struct hci_dev *hdev)
 210 {
 211         int err;
 212         struct ti_st *hst = hdev->driver_data;
 213
 214         if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 215                 return 0;
 216
 217         /* continue to unregister from transport */
 218         err = st_unregister(ST_BT);
 219         if (err)
 220                 BT_ERR("st_unregister() failed with error %d", err);
 221
 222         hst->st_write = NULL;
 223
 224         return err;
 225 }
 226
 227 static int ti_st_send_frame(struct sk_buff *skb)
 228 {
 229         struct hci_dev *hdev;
 230         struct ti_st *hst;
 231         long len;
 232
 233         hdev = (struct hci_dev *)skb->dev;
 234
 235         if (!test_bit(HCI_RUNNING, &hdev->flags))
 236                 return -EBUSY;
 237
 238         hst = hdev->driver_data;
 239
 240         /* Prepend skb with frame type */
 241         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 242
 243         BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type,
 244                         skb->len);
 245
 246         /* Insert skb to shared transport layer's transmit queue.
 247          * Freeing skb memory is taken care in shared transport layer,
 248          * so don't free skb memory here.
 249          */
 250         len = hst->st_write(skb);
 251         if (len < 0) {
 252                 kfree_skb(skb);
 253                 BT_ERR("ST write failed (%ld)", len);
 254                 /* Try Again, would only fail if UART has gone bad */
 255                 return -EAGAIN;
 256         }
 257
 258         /* ST accepted our skb. So, Go ahead and do rest */
 259         hdev->stat.byte_tx += len;
 260         ti_st_tx_complete(hst, bt_cb(skb)->pkt_type);
 261
 262         return 0;
 263 }
 264
 265 static void ti_st_destruct(struct hci_dev *hdev)
 266 {
 267         BT_DBG("%s", hdev->name);
 268         kfree(hdev->driver_data);
 269 }
 270
 271 static int bt_ti_probe(struct platform_device *pdev)
 272 {
 273         static struct ti_st *hst;
 274         struct hci_dev *hdev;
 275         int err;
 276
 277         hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL);
 278         if (!hst)
 279                 return -ENOMEM;
 280
 281         /* Expose "hciX" device to user space */
 282         hdev = hci_alloc_dev();
 283         if (!hdev) {
 284                 kfree(hst);
 285                 return -ENOMEM;
 286         }
 287
 288         BT_DBG("hdev %p", hdev);
 289
 290         hst->hdev = hdev;
 291         hdev->bus = HCI_UART;
 292         hdev->driver_data = hst;
 293         hdev->open = ti_st_open;
 294         hdev->close = ti_st_close;
 295         hdev->flush = NULL;
 296         hdev->send = ti_st_send_frame;
 297         hdev->destruct = ti_st_destruct;
 298         hdev->owner = THIS_MODULE;
 299
 300         err = hci_register_dev(hdev);
 301         if (err < 0) {
 302                 BT_ERR("Can't register HCI device error %d", err);
 303                 kfree(hst);
 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         hdev = hst->hdev;
 323         ti_st_close(hdev);
 324         hci_unregister_dev(hdev);
 325
 326         hci_free_dev(hdev);
 327         kfree(hst);
 328
 329         dev_set_drvdata(&pdev->dev, NULL);
 330         return 0;
 331 }
 332
 333 static struct platform_driver btwilink_driver = {
 334         .probe = bt_ti_probe,
 335         .remove = bt_ti_remove,
 336         .driver = {
 337                 .name = "btwilink",
 338                 .owner = THIS_MODULE,
 339         },
 340 };
 341
 342 /* ------- Module Init/Exit interfaces ------ */
 343 static int __init btwilink_init(void)
 344 {
 345         BT_INFO("Bluetooth Driver for TI WiLink - Version %s", VERSION);
 346
 347         return platform_driver_register(&btwilink_driver);
 348 }
 349
 350 static void __exit btwilink_exit(void)
 351 {
 352         platform_driver_unregister(&btwilink_driver);
 353 }
 354
 355 module_init(btwilink_init);
 356 module_exit(btwilink_exit);
 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");