LXR linux/drivers/bluetooth/hci

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Bluetooth HCI serdev driver lib
   4 *
   5 *  Copyright (C) 2017  Linaro, Ltd., Rob Herring <robh@kernel.org>
   6 *
   7 *  Based on hci_ldisc.c:
   8 *
   9 *  Copyright (C) 2000-2001  Qualcomm Incorporated
  10 *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
  11 *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/types.h>
  16#include <linux/serdev.h>
  17#include <linux/skbuff.h>
  18
  19#include <net/bluetooth/bluetooth.h>
  20#include <net/bluetooth/hci_core.h>
  21
  22#include "hci_uart.h"
  23
  24static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
  25{
  26        struct hci_dev *hdev = hu->hdev;
  27
  28        /* Update HCI stat counters */
  29        switch (pkt_type) {
  30        case HCI_COMMAND_PKT:
  31                hdev->stat.cmd_tx++;
  32                break;
  33
  34        case HCI_ACLDATA_PKT:
  35                hdev->stat.acl_tx++;
  36                break;
  37
  38        case HCI_SCODATA_PKT:
  39                hdev->stat.sco_tx++;
  40                break;
  41        }
  42}
  43
  44static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
  45{
  46        struct sk_buff *skb = hu->tx_skb;
  47
  48        if (!skb) {
  49                if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
  50                        skb = hu->proto->dequeue(hu);
  51        } else
  52                hu->tx_skb = NULL;
  53
  54        return skb;
  55}
  56
  57static void hci_uart_write_work(struct work_struct *work)
  58{
  59        struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
  60        struct serdev_device *serdev = hu->serdev;
  61        struct hci_dev *hdev = hu->hdev;
  62        struct sk_buff *skb;
  63
  64        /* REVISIT:
  65         * should we cope with bad skbs or ->write() returning an error value?
  66         */
  67        do {
  68                clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
  69
  70                while ((skb = hci_uart_dequeue(hu))) {
  71                        int len;
  72
  73                        len = serdev_device_write_buf(serdev,
  74                                                      skb->data, skb->len);
  75                        hdev->stat.byte_tx += len;
  76
  77                        skb_pull(skb, len);
  78                        if (skb->len) {
  79                                hu->tx_skb = skb;
  80                                break;
  81                        }
  82
  83                        hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
  84                        kfree_skb(skb);
  85                }
  86        } while (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
  87
  88        clear_bit(HCI_UART_SENDING, &hu->tx_state);
  89}
  90
  91/* ------- Interface to HCI layer ------ */
  92
  93/* Reset device */
  94static int hci_uart_flush(struct hci_dev *hdev)
  95{
  96        struct hci_uart *hu  = hci_get_drvdata(hdev);
  97
  98        BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
  99
 100        if (hu->tx_skb) {
 101                kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
 102        }
 103
 104        /* Flush any pending characters in the driver and discipline. */
 105        serdev_device_write_flush(hu->serdev);
 106
 107        if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 108                hu->proto->flush(hu);
 109
 110        return 0;
 111}
 112
 113/* Initialize device */
 114static int hci_uart_open(struct hci_dev *hdev)
 115{
 116        struct hci_uart *hu = hci_get_drvdata(hdev);
 117        int err;
 118
 119        BT_DBG("%s %p", hdev->name, hdev);
 120
 121        /* When Quirk HCI_QUIRK_NON_PERSISTENT_SETUP is set by
 122         * driver, BT SoC is completely turned OFF during
 123         * BT OFF. Upon next BT ON UART port should be opened.
 124         */
 125        if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 126                err = serdev_device_open(hu->serdev);
 127                if (err)
 128                        return err;
 129                set_bit(HCI_UART_PROTO_READY, &hu->flags);
 130        }
 131
 132        /* Undo clearing this from hci_uart_close() */
 133        hdev->flush = hci_uart_flush;
 134
 135        return 0;
 136}
 137
 138/* Close device */
 139static int hci_uart_close(struct hci_dev *hdev)
 140{
 141        struct hci_uart *hu = hci_get_drvdata(hdev);
 142
 143        BT_DBG("hdev %p", hdev);
 144
 145        if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
 146                return 0;
 147
 148        hci_uart_flush(hdev);
 149        hdev->flush = NULL;
 150
 151        /* When QUIRK HCI_QUIRK_NON_PERSISTENT_SETUP is set by driver,
 152         * BT SOC is completely powered OFF during BT OFF, holding port
 153         * open may drain the battery.
 154         */
 155        if (test_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks)) {
 156                clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 157                serdev_device_close(hu->serdev);
 158        }
 159
 160        return 0;
 161}
 162
 163/* Send frames from HCI layer */
 164static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 165{
 166        struct hci_uart *hu = hci_get_drvdata(hdev);
 167
 168        BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
 169               skb->len);
 170
 171        hu->proto->enqueue(hu, skb);
 172
 173        hci_uart_tx_wakeup(hu);
 174
 175        return 0;
 176}
 177
 178static int hci_uart_setup(struct hci_dev *hdev)
 179{
 180        struct hci_uart *hu = hci_get_drvdata(hdev);
 181        struct hci_rp_read_local_version *ver;
 182        struct sk_buff *skb;
 183        unsigned int speed;
 184        int err;
 185
 186        /* Init speed if any */
 187        if (hu->init_speed)
 188                speed = hu->init_speed;
 189        else if (hu->proto->init_speed)
 190                speed = hu->proto->init_speed;
 191        else
 192                speed = 0;
 193
 194        if (speed)
 195                serdev_device_set_baudrate(hu->serdev, speed);
 196
 197        /* Operational speed if any */
 198        if (hu->oper_speed)
 199                speed = hu->oper_speed;
 200        else if (hu->proto->oper_speed)
 201                speed = hu->proto->oper_speed;
 202        else
 203                speed = 0;
 204
 205        if (hu->proto->set_baudrate && speed) {
 206                err = hu->proto->set_baudrate(hu, speed);
 207                if (err)
 208                        bt_dev_err(hdev, "Failed to set baudrate");
 209                else
 210                        serdev_device_set_baudrate(hu->serdev, speed);
 211        }
 212
 213        if (hu->proto->setup)
 214                return hu->proto->setup(hu);
 215
 216        if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
 217                return 0;
 218
 219        skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 220                             HCI_INIT_TIMEOUT);
 221        if (IS_ERR(skb)) {
 222                bt_dev_err(hdev, "Reading local version info failed (%ld)",
 223                           PTR_ERR(skb));
 224                return 0;
 225        }
 226
 227        if (skb->len != sizeof(*ver))
 228                bt_dev_err(hdev, "Event length mismatch for version info");
 229
 230        kfree_skb(skb);
 231        return 0;
 232}
 233
 234/** hci_uart_write_wakeup - transmit buffer wakeup
 235 * @serdev: serial device
 236 *
 237 * This function is called by the serdev framework when it accepts
 238 * more data being sent.
 239 */
 240static void hci_uart_write_wakeup(struct serdev_device *serdev)
 241{
 242        struct hci_uart *hu = serdev_device_get_drvdata(serdev);
 243
 244        BT_DBG("");
 245
 246        if (!hu || serdev != hu->serdev) {
 247                WARN_ON(1);
 248                return;
 249        }
 250
 251        if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 252                hci_uart_tx_wakeup(hu);
 253}
 254
 255/** hci_uart_receive_buf - receive buffer wakeup
 256 * @serdev: serial device
 257 * @data:   pointer to received data
 258 * @count:  count of received data in bytes
 259 *
 260 * This function is called by the serdev framework when it received data
 261 * in the RX buffer.
 262 *
 263 * Return: number of processed bytes
 264 */
 265static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
 266                                   size_t count)
 267{
 268        struct hci_uart *hu = serdev_device_get_drvdata(serdev);
 269
 270        if (!hu || serdev != hu->serdev) {
 271                WARN_ON(1);
 272                return 0;
 273        }
 274
 275        if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
 276                return 0;
 277
 278        /* It does not need a lock here as it is already protected by a mutex in
 279         * tty caller
 280         */
 281        hu->proto->recv(hu, data, count);
 282
 283        if (hu->hdev)
 284                hu->hdev->stat.byte_rx += count;
 285
 286        return count;
 287}
 288
 289static const struct serdev_device_ops hci_serdev_client_ops = {
 290        .receive_buf = hci_uart_receive_buf,
 291        .write_wakeup = hci_uart_write_wakeup,
 292};
 293
 294int hci_uart_register_device(struct hci_uart *hu,
 295                             const struct hci_uart_proto *p)
 296{
 297        int err;
 298        struct hci_dev *hdev;
 299
 300        BT_DBG("");
 301
 302        serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
 303
 304        err = serdev_device_open(hu->serdev);
 305        if (err)
 306                return err;
 307
 308        err = p->open(hu);
 309        if (err)
 310                goto err_open;
 311
 312        hu->proto = p;
 313        set_bit(HCI_UART_PROTO_READY, &hu->flags);
 314
 315        /* Initialize and register HCI device */
 316        hdev = hci_alloc_dev();
 317        if (!hdev) {
 318                BT_ERR("Can't allocate HCI device");
 319                err = -ENOMEM;
 320                goto err_alloc;
 321        }
 322
 323        hu->hdev = hdev;
 324
 325        hdev->bus = HCI_UART;
 326        hci_set_drvdata(hdev, hu);
 327
 328        INIT_WORK(&hu->init_ready, hci_uart_init_work);
 329        INIT_WORK(&hu->write_work, hci_uart_write_work);
 330        percpu_init_rwsem(&hu->proto_lock);
 331
 332        /* Only when vendor specific setup callback is provided, consider
 333         * the manufacturer information valid. This avoids filling in the
 334         * value for Ericsson when nothing is specified.
 335         */
 336        if (hu->proto->setup)
 337                hdev->manufacturer = hu->proto->manufacturer;
 338
 339        hdev->open  = hci_uart_open;
 340        hdev->close = hci_uart_close;
 341        hdev->flush = hci_uart_flush;
 342        hdev->send  = hci_uart_send_frame;
 343        hdev->setup = hci_uart_setup;
 344        SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
 345
 346        if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
 347                set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 348
 349        if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
 350                set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
 351
 352        if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
 353                hdev->dev_type = HCI_AMP;
 354        else
 355                hdev->dev_type = HCI_PRIMARY;
 356
 357        if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
 358                return 0;
 359
 360        if (hci_register_dev(hdev) < 0) {
 361                BT_ERR("Can't register HCI device");
 362                err = -ENODEV;
 363                goto err_register;
 364        }
 365
 366        set_bit(HCI_UART_REGISTERED, &hu->flags);
 367
 368        return 0;
 369
 370err_register:
 371        hci_free_dev(hdev);
 372err_alloc:
 373        clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 374        p->close(hu);
 375err_open:
 376        serdev_device_close(hu->serdev);
 377        return err;
 378}
 379EXPORT_SYMBOL_GPL(hci_uart_register_device);
 380
 381void hci_uart_unregister_device(struct hci_uart *hu)
 382{
 383        struct hci_dev *hdev = hu->hdev;
 384
 385        cancel_work_sync(&hu->init_ready);
 386        if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 387                hci_unregister_dev(hdev);
 388        hci_free_dev(hdev);
 389
 390        cancel_work_sync(&hu->write_work);
 391
 392        hu->proto->close(hu);
 393
 394        if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
 395                clear_bit(HCI_UART_PROTO_READY, &hu->flags);
 396                serdev_device_close(hu->serdev);
 397        }
 398}
 399EXPORT_SYMBOL_GPL(hci_uart_unregister_device);
 400