1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Bluetooth HCI UART driver
6 * Copyright (C) 2000-2001 Qualcomm Incorporated
7 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
8 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
11 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/fcntl.h>
17 #include <linux/interrupt.h>
18 #include <linux/ptrace.h>
19 #include <linux/poll.h>
21 #include <linux/slab.h>
22 #include <linux/tty.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/signal.h>
26 #include <linux/ioctl.h>
27 #include <linux/skbuff.h>
28 #include <linux/firmware.h>
29 #include <linux/serdev.h>
31 #include <net/bluetooth/bluetooth.h>
32 #include <net/bluetooth/hci_core.h>
40 static const struct hci_uart_proto *hup[HCI_UART_MAX_PROTO];
42 int hci_uart_register_proto(const struct hci_uart_proto *p)
44 if (p->id >= HCI_UART_MAX_PROTO)
52 BT_INFO("HCI UART protocol %s registered", p->name);
57 int hci_uart_unregister_proto(const struct hci_uart_proto *p)
59 if (p->id >= HCI_UART_MAX_PROTO)
70 static const struct hci_uart_proto *hci_uart_get_proto(unsigned int id)
72 if (id >= HCI_UART_MAX_PROTO)
78 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
80 struct hci_dev *hdev = hu->hdev;
82 /* Update HCI stat counters */
98 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
100 struct sk_buff *skb = hu->tx_skb;
103 percpu_down_read(&hu->proto_lock);
105 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
106 skb = hu->proto->dequeue(hu);
108 percpu_up_read(&hu->proto_lock);
116 int hci_uart_tx_wakeup(struct hci_uart *hu)
118 /* This may be called in an IRQ context, so we can't sleep. Therefore
119 * we try to acquire the lock only, and if that fails we assume the
120 * tty is being closed because that is the only time the write lock is
121 * acquired. If, however, at some point in the future the write lock
122 * is also acquired in other situations, then this must be revisited.
124 if (!percpu_down_read_trylock(&hu->proto_lock))
127 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
130 set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
131 if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state))
136 schedule_work(&hu->write_work);
139 percpu_up_read(&hu->proto_lock);
143 EXPORT_SYMBOL_GPL(hci_uart_tx_wakeup);
145 static void hci_uart_write_work(struct work_struct *work)
147 struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
148 struct tty_struct *tty = hu->tty;
149 struct hci_dev *hdev = hu->hdev;
152 /* REVISIT: should we cope with bad skbs or ->write() returning
157 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
159 while ((skb = hci_uart_dequeue(hu))) {
162 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
163 len = tty->ops->write(tty, skb->data, skb->len);
164 hdev->stat.byte_tx += len;
172 hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
176 clear_bit(HCI_UART_SENDING, &hu->tx_state);
177 if (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state))
180 wake_up_bit(&hu->tx_state, HCI_UART_SENDING);
183 void hci_uart_init_work(struct work_struct *work)
185 struct hci_uart *hu = container_of(work, struct hci_uart, init_ready);
187 struct hci_dev *hdev;
189 if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
192 err = hci_register_dev(hu->hdev);
194 BT_ERR("Can't register HCI device");
195 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
196 hu->proto->close(hu);
203 set_bit(HCI_UART_REGISTERED, &hu->flags);
206 int hci_uart_init_ready(struct hci_uart *hu)
208 if (!test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
211 schedule_work(&hu->init_ready);
216 int hci_uart_wait_until_sent(struct hci_uart *hu)
218 return wait_on_bit_timeout(&hu->tx_state, HCI_UART_SENDING,
220 msecs_to_jiffies(2000));
223 /* ------- Interface to HCI layer ------ */
225 static int hci_uart_flush(struct hci_dev *hdev)
227 struct hci_uart *hu = hci_get_drvdata(hdev);
228 struct tty_struct *tty = hu->tty;
230 BT_DBG("hdev %p tty %p", hdev, tty);
233 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
236 /* Flush any pending characters in the driver and discipline. */
237 tty_ldisc_flush(tty);
238 tty_driver_flush_buffer(tty);
240 percpu_down_read(&hu->proto_lock);
242 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
243 hu->proto->flush(hu);
245 percpu_up_read(&hu->proto_lock);
250 /* Initialize device */
251 static int hci_uart_open(struct hci_dev *hdev)
253 BT_DBG("%s %p", hdev->name, hdev);
255 /* Undo clearing this from hci_uart_close() */
256 hdev->flush = hci_uart_flush;
262 static int hci_uart_close(struct hci_dev *hdev)
264 BT_DBG("hdev %p", hdev);
266 hci_uart_flush(hdev);
271 /* Send frames from HCI layer */
272 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
274 struct hci_uart *hu = hci_get_drvdata(hdev);
276 BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
279 percpu_down_read(&hu->proto_lock);
281 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
282 percpu_up_read(&hu->proto_lock);
286 hu->proto->enqueue(hu, skb);
287 percpu_up_read(&hu->proto_lock);
289 hci_uart_tx_wakeup(hu);
294 /* Check the underlying device or tty has flow control support */
295 bool hci_uart_has_flow_control(struct hci_uart *hu)
297 /* serdev nodes check if the needed operations are present */
301 if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
307 /* Flow control or un-flow control the device */
308 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
310 struct tty_struct *tty = hu->tty;
311 struct ktermios ktermios;
313 unsigned int set = 0;
314 unsigned int clear = 0;
317 serdev_device_set_flow_control(hu->serdev, !enable);
318 serdev_device_set_rts(hu->serdev, !enable);
323 /* Disable hardware flow control */
324 ktermios = tty->termios;
325 ktermios.c_cflag &= ~CRTSCTS;
326 status = tty_set_termios(tty, &ktermios);
327 BT_DBG("Disabling hardware flow control: %s",
328 status ? "failed" : "success");
330 /* Clear RTS to prevent the device from sending */
331 /* Most UARTs need OUT2 to enable interrupts */
332 status = tty->driver->ops->tiocmget(tty);
333 BT_DBG("Current tiocm 0x%x", status);
335 set &= ~(TIOCM_OUT2 | TIOCM_RTS);
337 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
338 TIOCM_OUT2 | TIOCM_LOOP;
339 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
340 TIOCM_OUT2 | TIOCM_LOOP;
341 status = tty->driver->ops->tiocmset(tty, set, clear);
342 BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
344 /* Set RTS to allow the device to send again */
345 status = tty->driver->ops->tiocmget(tty);
346 BT_DBG("Current tiocm 0x%x", status);
348 set |= (TIOCM_OUT2 | TIOCM_RTS);
350 set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
351 TIOCM_OUT2 | TIOCM_LOOP;
352 clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
353 TIOCM_OUT2 | TIOCM_LOOP;
354 status = tty->driver->ops->tiocmset(tty, set, clear);
355 BT_DBG("Setting RTS: %s", status ? "failed" : "success");
357 /* Re-enable hardware flow control */
358 ktermios = tty->termios;
359 ktermios.c_cflag |= CRTSCTS;
360 status = tty_set_termios(tty, &ktermios);
361 BT_DBG("Enabling hardware flow control: %s",
362 status ? "failed" : "success");
366 void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed,
367 unsigned int oper_speed)
369 hu->init_speed = init_speed;
370 hu->oper_speed = oper_speed;
373 void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed)
375 struct tty_struct *tty = hu->tty;
376 struct ktermios ktermios;
378 ktermios = tty->termios;
379 ktermios.c_cflag &= ~CBAUD;
380 tty_termios_encode_baud_rate(&ktermios, speed, speed);
382 /* tty_set_termios() return not checked as it is always 0 */
383 tty_set_termios(tty, &ktermios);
385 BT_DBG("%s: New tty speeds: %d/%d", hu->hdev->name,
386 tty->termios.c_ispeed, tty->termios.c_ospeed);
389 static int hci_uart_setup(struct hci_dev *hdev)
391 struct hci_uart *hu = hci_get_drvdata(hdev);
392 struct hci_rp_read_local_version *ver;
397 /* Init speed if any */
399 speed = hu->init_speed;
400 else if (hu->proto->init_speed)
401 speed = hu->proto->init_speed;
406 hci_uart_set_baudrate(hu, speed);
408 /* Operational speed if any */
410 speed = hu->oper_speed;
411 else if (hu->proto->oper_speed)
412 speed = hu->proto->oper_speed;
416 if (hu->proto->set_baudrate && speed) {
417 err = hu->proto->set_baudrate(hu, speed);
419 hci_uart_set_baudrate(hu, speed);
422 if (hu->proto->setup)
423 return hu->proto->setup(hu);
425 if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
428 skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
431 BT_ERR("%s: Reading local version information failed (%ld)",
432 hdev->name, PTR_ERR(skb));
436 if (skb->len != sizeof(*ver)) {
437 BT_ERR("%s: Event length mismatch for version information",
442 ver = (struct hci_rp_read_local_version *)skb->data;
444 switch (le16_to_cpu(ver->manufacturer)) {
445 #ifdef CONFIG_BT_HCIUART_INTEL
447 hdev->set_bdaddr = btintel_set_bdaddr;
448 btintel_check_bdaddr(hdev);
451 #ifdef CONFIG_BT_HCIUART_BCM
453 hdev->set_bdaddr = btbcm_set_bdaddr;
454 btbcm_check_bdaddr(hdev);
466 /* ------ LDISC part ------ */
469 * Called when line discipline changed to HCI_UART.
472 * tty pointer to tty info structure
474 * 0 if success, otherwise error code
476 static int hci_uart_tty_open(struct tty_struct *tty)
480 BT_DBG("tty %p", tty);
482 /* Error if the tty has no write op instead of leaving an exploitable
485 if (tty->ops->write == NULL)
488 hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
490 BT_ERR("Can't allocate control structure");
493 if (percpu_init_rwsem(&hu->proto_lock)) {
494 BT_ERR("Can't allocate semaphore structure");
501 tty->receive_room = 65536;
503 /* disable alignment support by default */
507 INIT_WORK(&hu->init_ready, hci_uart_init_work);
508 INIT_WORK(&hu->write_work, hci_uart_write_work);
510 /* Flush any pending characters in the driver */
511 tty_driver_flush_buffer(tty);
516 /* hci_uart_tty_close()
518 * Called when the line discipline is changed to something
519 * else, the tty is closed, or the tty detects a hangup.
521 static void hci_uart_tty_close(struct tty_struct *tty)
523 struct hci_uart *hu = tty->disc_data;
524 struct hci_dev *hdev;
526 BT_DBG("tty %p", tty);
528 /* Detach from the tty */
529 tty->disc_data = NULL;
536 hci_uart_close(hdev);
538 if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
539 percpu_down_write(&hu->proto_lock);
540 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
541 percpu_up_write(&hu->proto_lock);
543 cancel_work_sync(&hu->init_ready);
544 cancel_work_sync(&hu->write_work);
547 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
548 hci_unregister_dev(hdev);
551 hu->proto->close(hu);
553 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
555 percpu_free_rwsem(&hu->proto_lock);
560 /* hci_uart_tty_wakeup()
562 * Callback for transmit wakeup. Called when low level
563 * device driver can accept more send data.
565 * Arguments: tty pointer to associated tty instance data
568 static void hci_uart_tty_wakeup(struct tty_struct *tty)
570 struct hci_uart *hu = tty->disc_data;
577 clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
582 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
583 hci_uart_tx_wakeup(hu);
586 /* hci_uart_tty_receive()
588 * Called by tty low level driver when receive data is
591 * Arguments: tty pointer to tty isntance data
592 * data pointer to received data
593 * flags pointer to flags for data
594 * count count of received data in bytes
598 static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data,
599 char *flags, int count)
601 struct hci_uart *hu = tty->disc_data;
603 if (!hu || tty != hu->tty)
606 percpu_down_read(&hu->proto_lock);
608 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
609 percpu_up_read(&hu->proto_lock);
613 /* It does not need a lock here as it is already protected by a mutex in
616 hu->proto->recv(hu, data, count);
617 percpu_up_read(&hu->proto_lock);
620 hu->hdev->stat.byte_rx += count;
625 static int hci_uart_register_dev(struct hci_uart *hu)
627 struct hci_dev *hdev;
632 /* Initialize and register HCI device */
633 hdev = hci_alloc_dev();
635 BT_ERR("Can't allocate HCI device");
641 hdev->bus = HCI_UART;
642 hci_set_drvdata(hdev, hu);
644 /* Only when vendor specific setup callback is provided, consider
645 * the manufacturer information valid. This avoids filling in the
646 * value for Ericsson when nothing is specified.
648 if (hu->proto->setup)
649 hdev->manufacturer = hu->proto->manufacturer;
651 hdev->open = hci_uart_open;
652 hdev->close = hci_uart_close;
653 hdev->flush = hci_uart_flush;
654 hdev->send = hci_uart_send_frame;
655 hdev->setup = hci_uart_setup;
656 SET_HCIDEV_DEV(hdev, hu->tty->dev);
658 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
659 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
661 if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
662 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
664 if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
665 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
667 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
668 hdev->dev_type = HCI_AMP;
670 hdev->dev_type = HCI_PRIMARY;
672 /* Only call open() for the protocol after hdev is fully initialized as
673 * open() (or a timer/workqueue it starts) may attempt to reference it.
675 err = hu->proto->open(hu);
682 if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
685 if (hci_register_dev(hdev) < 0) {
686 BT_ERR("Can't register HCI device");
687 hu->proto->close(hu);
693 set_bit(HCI_UART_REGISTERED, &hu->flags);
698 static int hci_uart_set_proto(struct hci_uart *hu, int id)
700 const struct hci_uart_proto *p;
703 p = hci_uart_get_proto(id);
705 return -EPROTONOSUPPORT;
709 err = hci_uart_register_dev(hu);
714 set_bit(HCI_UART_PROTO_READY, &hu->flags);
718 static int hci_uart_set_flags(struct hci_uart *hu, unsigned long flags)
720 unsigned long valid_flags = BIT(HCI_UART_RAW_DEVICE) |
721 BIT(HCI_UART_RESET_ON_INIT) |
722 BIT(HCI_UART_CREATE_AMP) |
723 BIT(HCI_UART_INIT_PENDING) |
724 BIT(HCI_UART_EXT_CONFIG) |
725 BIT(HCI_UART_VND_DETECT);
727 if (flags & ~valid_flags)
730 hu->hdev_flags = flags;
735 /* hci_uart_tty_ioctl()
737 * Process IOCTL system call for the tty device.
741 * tty pointer to tty instance data
742 * file pointer to open file object for device
743 * cmd IOCTL command code
744 * arg argument for IOCTL call (cmd dependent)
746 * Return Value: Command dependent
748 static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
749 unsigned int cmd, unsigned long arg)
751 struct hci_uart *hu = tty->disc_data;
756 /* Verify the status of the device */
761 case HCIUARTSETPROTO:
762 if (!test_and_set_bit(HCI_UART_PROTO_SET, &hu->flags)) {
763 err = hci_uart_set_proto(hu, arg);
765 clear_bit(HCI_UART_PROTO_SET, &hu->flags);
770 case HCIUARTGETPROTO:
771 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
777 case HCIUARTGETDEVICE:
778 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
784 case HCIUARTSETFLAGS:
785 if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
788 err = hci_uart_set_flags(hu, arg);
791 case HCIUARTGETFLAGS:
792 err = hu->hdev_flags;
796 err = n_tty_ioctl_helper(tty, file, cmd, arg);
804 * We don't provide read/write/poll interface for user space.
806 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
807 unsigned char *buf, size_t nr,
808 void **cookie, unsigned long offset)
813 static ssize_t hci_uart_tty_write(struct tty_struct *tty, struct file *file,
814 const unsigned char *data, size_t count)
819 static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
820 struct file *filp, poll_table *wait)
825 static struct tty_ldisc_ops hci_uart_ldisc = {
826 .owner = THIS_MODULE,
827 .magic = TTY_LDISC_MAGIC,
829 .open = hci_uart_tty_open,
830 .close = hci_uart_tty_close,
831 .read = hci_uart_tty_read,
832 .write = hci_uart_tty_write,
833 .ioctl = hci_uart_tty_ioctl,
834 .compat_ioctl = hci_uart_tty_ioctl,
835 .poll = hci_uart_tty_poll,
836 .receive_buf = hci_uart_tty_receive,
837 .write_wakeup = hci_uart_tty_wakeup,
840 static int __init hci_uart_init(void)
844 BT_INFO("HCI UART driver ver %s", VERSION);
846 /* Register the tty discipline */
847 err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
849 BT_ERR("HCI line discipline registration failed. (%d)", err);
853 #ifdef CONFIG_BT_HCIUART_H4
856 #ifdef CONFIG_BT_HCIUART_BCSP
859 #ifdef CONFIG_BT_HCIUART_LL
862 #ifdef CONFIG_BT_HCIUART_ATH3K
865 #ifdef CONFIG_BT_HCIUART_3WIRE
868 #ifdef CONFIG_BT_HCIUART_INTEL
871 #ifdef CONFIG_BT_HCIUART_BCM
874 #ifdef CONFIG_BT_HCIUART_QCA
877 #ifdef CONFIG_BT_HCIUART_AG6XX
880 #ifdef CONFIG_BT_HCIUART_MRVL
887 static void __exit hci_uart_exit(void)
891 #ifdef CONFIG_BT_HCIUART_H4
894 #ifdef CONFIG_BT_HCIUART_BCSP
897 #ifdef CONFIG_BT_HCIUART_LL
900 #ifdef CONFIG_BT_HCIUART_ATH3K
903 #ifdef CONFIG_BT_HCIUART_3WIRE
906 #ifdef CONFIG_BT_HCIUART_INTEL
909 #ifdef CONFIG_BT_HCIUART_BCM
912 #ifdef CONFIG_BT_HCIUART_QCA
915 #ifdef CONFIG_BT_HCIUART_AG6XX
918 #ifdef CONFIG_BT_HCIUART_MRVL
922 /* Release tty registration of line discipline */
923 err = tty_unregister_ldisc(N_HCI);
925 BT_ERR("Can't unregister HCI line discipline (%d)", err);
928 module_init(hci_uart_init);
929 module_exit(hci_uart_exit);
931 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
932 MODULE_DESCRIPTION("Bluetooth HCI UART driver ver " VERSION);
933 MODULE_VERSION(VERSION);
934 MODULE_LICENSE("GPL");
935 MODULE_ALIAS_LDISC(N_HCI);