root/drivers/bluetooth/btwilink.c

DEFINITIONS

1. ti_st_tx_complete
2. st_reg_completion_cb
3. st_receive
4. ti_st_open
5. ti_st_close
6. ti_st_send_frame
7. bt_ti_probe
8. bt_ti_remove

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Texas Instrument's Bluetooth Driver For Shared Transport.
   4  *
   5  *  Bluetooth Driver acts as interface between HCI core and
   6  *  TI Shared Transport Layer.
   7  *
   8  *  Copyright (C) 2009-2010 Texas Instruments
   9  *  Author: Raja Mani <raja_mani@ti.com>
  10  *      Pavan Savoy <pavan_savoy@ti.com>
  11  */
  12 
  13 #include <linux/platform_device.h>
  14 #include <net/bluetooth/bluetooth.h>
  15 #include <net/bluetooth/hci_core.h>
  16 #include <net/bluetooth/hci.h>
  17 
  18 #include <linux/ti_wilink_st.h>
  19 #include <linux/module.h>
  20 
  21 /* Bluetooth Driver Version */
  22 #define VERSION               "1.0"
  23 #define MAX_BT_CHNL_IDS         3
  24 
  25 /* Number of seconds to wait for registration completion
  26  * when ST returns PENDING status.
  27  */
  28 #define BT_REGISTER_TIMEOUT   6000      /* 6 sec */
  29 
  30 /**
  31  * struct ti_st - driver operation structure
  32  * @hdev: hci device pointer which binds to bt driver
  33  * @reg_status: ST registration callback status
  34  * @st_write: write function provided by the ST driver
  35  *      to be used by the driver during send_frame.
  36  * @wait_reg_completion - completion sync between ti_st_open
  37  *      and st_reg_completion_cb.
  38  */
  39 struct ti_st {
  40         struct hci_dev *hdev;
  41         int reg_status;
  42         long (*st_write) (struct sk_buff *);
  43         struct completion wait_reg_completion;
  44 };
  45 
  46 /* Increments HCI counters based on pocket ID (cmd,acl,sco) */
  47 static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
  48 {
  49         struct hci_dev *hdev = hst->hdev;
  50 
  51         /* Update HCI stat counters */
  52         switch (pkt_type) {
  53         case HCI_COMMAND_PKT:
  54                 hdev->stat.cmd_tx++;
  55                 break;
  56 
  57         case HCI_ACLDATA_PKT:
  58                 hdev->stat.acl_tx++;
  59                 break;
  60 
  61         case HCI_SCODATA_PKT:
  62                 hdev->stat.sco_tx++;
  63                 break;
  64         }
  65 }
  66 
  67 /* ------- Interfaces to Shared Transport ------ */
  68 
  69 /* Called by ST layer to indicate protocol registration completion
  70  * status.ti_st_open() function will wait for signal from this
  71  * API when st_register() function returns ST_PENDING.
  72  */
  73 static void st_reg_completion_cb(void *priv_data, int data)
  74 {
  75         struct ti_st *lhst = priv_data;
  76 
  77         /* Save registration status for use in ti_st_open() */
  78         lhst->reg_status = data;
  79         /* complete the wait in ti_st_open() */
  80         complete(&lhst->wait_reg_completion);
  81 }
  82 
  83 /* Called by Shared Transport layer when receive data is available */
  84 static long st_receive(void *priv_data, struct sk_buff *skb)
  85 {
  86         struct ti_st *lhst = priv_data;
  87         int err;
  88 
  89         if (!skb)
  90                 return -EFAULT;
  91 
  92         if (!lhst) {
  93                 kfree_skb(skb);
  94                 return -EFAULT;
  95         }
  96 
  97         /* Forward skb to HCI core layer */
  98         err = hci_recv_frame(lhst->hdev, skb);
  99         if (err < 0) {
 100                 BT_ERR("Unable to push skb to HCI core(%d)", err);
 101                 return err;
 102         }
 103 
 104         lhst->hdev->stat.byte_rx += skb->len;
 105 
 106         return 0;
 107 }
 108 
 109 /* ------- Interfaces to HCI layer ------ */
 110 /* protocol structure registered with shared transport */
 111 static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
 112         {
 113                 .chnl_id = HCI_EVENT_PKT, /* HCI Events */
 114                 .hdr_len = sizeof(struct hci_event_hdr),
 115                 .offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
 116                 .len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
 117                 .reserve = 8,
 118         },
 119         {
 120                 .chnl_id = HCI_ACLDATA_PKT, /* ACL */
 121                 .hdr_len = sizeof(struct hci_acl_hdr),
 122                 .offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
 123                 .len_size = 2,  /* sizeof(dlen) in struct hci_acl_hdr */
 124                 .reserve = 8,
 125         },
 126         {
 127                 .chnl_id = HCI_SCODATA_PKT, /* SCO */
 128                 .hdr_len = sizeof(struct hci_sco_hdr),
 129                 .offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
 130                 .len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
 131                 .reserve = 8,
 132         },
 133 };
 134 
 135 /* Called from HCI core to initialize the device */
 136 static int ti_st_open(struct hci_dev *hdev)
 137 {
 138         unsigned long timeleft;
 139         struct ti_st *hst;
 140         int err, i;
 141 
 142         BT_DBG("%s %p", hdev->name, hdev);
 143 
 144         /* provide contexts for callbacks from ST */
 145         hst = hci_get_drvdata(hdev);
 146 
 147         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 148                 ti_st_proto[i].priv_data = hst;
 149                 ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
 150                 ti_st_proto[i].recv = st_receive;
 151                 ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
 152 
 153                 /* Prepare wait-for-completion handler */
 154                 init_completion(&hst->wait_reg_completion);
 155                 /* Reset ST registration callback status flag,
 156                  * this value will be updated in
 157                  * st_reg_completion_cb()
 158                  * function whenever it called from ST driver.
 159                  */
 160                 hst->reg_status = -EINPROGRESS;
 161 
 162                 err = st_register(&ti_st_proto[i]);
 163                 if (!err)
 164                         goto done;
 165 
 166                 if (err != -EINPROGRESS) {
 167                         BT_ERR("st_register failed %d", err);
 168                         return err;
 169                 }
 170 
 171                 /* ST is busy with either protocol
 172                  * registration or firmware download.
 173                  */
 174                 BT_DBG("waiting for registration "
 175                                 "completion signal from ST");
 176                 timeleft = wait_for_completion_timeout
 177                         (&hst->wait_reg_completion,
 178                          msecs_to_jiffies(BT_REGISTER_TIMEOUT));
 179                 if (!timeleft) {
 180                         BT_ERR("Timeout(%d sec),didn't get reg "
 181                                         "completion signal from ST",
 182                                         BT_REGISTER_TIMEOUT / 1000);
 183                         return -ETIMEDOUT;
 184                 }
 185 
 186                 /* Is ST registration callback
 187                  * called with ERROR status?
 188                  */
 189                 if (hst->reg_status != 0) {
 190                         BT_ERR("ST registration completed with invalid "
 191                                         "status %d", hst->reg_status);
 192                         return -EAGAIN;
 193                 }
 194 
 195 done:
 196                 hst->st_write = ti_st_proto[i].write;
 197                 if (!hst->st_write) {
 198                         BT_ERR("undefined ST write function");
 199                         for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
 200                                 /* Undo registration with ST */
 201                                 err = st_unregister(&ti_st_proto[i]);
 202                                 if (err)
 203                                         BT_ERR("st_unregister() failed with "
 204                                                         "error %d", err);
 205                                 hst->st_write = NULL;
 206                         }
 207                         return -EIO;
 208                 }
 209         }
 210         return 0;
 211 }
 212 
 213 /* Close device */
 214 static int ti_st_close(struct hci_dev *hdev)
 215 {
 216         int err, i;
 217         struct ti_st *hst = hci_get_drvdata(hdev);
 218 
 219         for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
 220                 err = st_unregister(&ti_st_proto[i]);
 221                 if (err)
 222                         BT_ERR("st_unregister(%d) failed with error %d",
 223                                         ti_st_proto[i].chnl_id, err);
 224         }
 225 
 226         hst->st_write = NULL;
 227 
 228         return err;
 229 }
 230 
 231 static int ti_st_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 232 {
 233         struct ti_st *hst;
 234         long len;
 235         int pkt_type;
 236 
 237         hst = hci_get_drvdata(hdev);
 238 
 239         /* Prepend skb with frame type */
 240         memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
 241 
 242         BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
 243                skb->len);
 244 
 245         /* Insert skb to shared transport layer's transmit queue.
 246          * Freeing skb memory is taken care in shared transport layer,
 247          * so don't free skb memory here.
 248          */
 249         pkt_type = hci_skb_pkt_type(skb);
 250         len = hst->st_write(skb);
 251         if (len < 0) {
 252                 BT_ERR("ST write failed (%ld)", len);
 253                 /* Try Again, would only fail if UART has gone bad */
 254                 return -EAGAIN;
 255         }
 256 
 257         /* ST accepted our skb. So, Go ahead and do rest */
 258         hdev->stat.byte_tx += len;
 259         ti_st_tx_complete(hst, pkt_type);
 260 
 261         return 0;
 262 }
 263 
 264 static int bt_ti_probe(struct platform_device *pdev)
 265 {
 266         struct ti_st *hst;
 267         struct hci_dev *hdev;
 268         int err;
 269 
 270         hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
 271         if (!hst)
 272                 return -ENOMEM;
 273 
 274         /* Expose "hciX" device to user space */
 275         hdev = hci_alloc_dev();
 276         if (!hdev)
 277                 return -ENOMEM;
 278 
 279         BT_DBG("hdev %p", hdev);
 280 
 281         hst->hdev = hdev;
 282         hdev->bus = HCI_UART;
 283         hci_set_drvdata(hdev, hst);
 284         hdev->open = ti_st_open;
 285         hdev->close = ti_st_close;
 286         hdev->flush = NULL;
 287         hdev->send = ti_st_send_frame;
 288 
 289         err = hci_register_dev(hdev);
 290         if (err < 0) {
 291                 BT_ERR("Can't register HCI device error %d", err);
 292                 hci_free_dev(hdev);
 293                 return err;
 294         }
 295 
 296         BT_DBG("HCI device registered (hdev %p)", hdev);
 297 
 298         dev_set_drvdata(&pdev->dev, hst);
 299         return 0;
 300 }
 301 
 302 static int bt_ti_remove(struct platform_device *pdev)
 303 {
 304         struct hci_dev *hdev;
 305         struct ti_st *hst = dev_get_drvdata(&pdev->dev);
 306 
 307         if (!hst)
 308                 return -EFAULT;
 309 
 310         BT_DBG("%s", hst->hdev->name);
 311 
 312         hdev = hst->hdev;
 313         ti_st_close(hdev);
 314         hci_unregister_dev(hdev);
 315 
 316         hci_free_dev(hdev);
 317 
 318         dev_set_drvdata(&pdev->dev, NULL);
 319         return 0;
 320 }
 321 
 322 static struct platform_driver btwilink_driver = {
 323         .probe = bt_ti_probe,
 324         .remove = bt_ti_remove,
 325         .driver = {
 326                 .name = "btwilink",
 327         },
 328 };
 329 
 330 module_platform_driver(btwilink_driver);
 331 
 332 /* ------ Module Info ------ */
 333 
 334 MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
 335 MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
 336 MODULE_VERSION(VERSION);
 337 MODULE_LICENSE("GPL");