[Xenial,SRU,CVE-2019-10207,1/2] Bluetooth: hci_uart: add serdev driver support library
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Message ID 20190812230845.18011-2-connor.kuehl@canonical.com
State New
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  • [Xenial,SRU,CVE-2019-10207,1/2] Bluetooth: hci_uart: add serdev driver support library
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Commit Message

Connor Kuehl Aug. 12, 2019, 11:08 p.m. UTC
From: Rob Herring <robh@kernel.org>

CVE-2019-10207

This adds library functions for serdev based BT drivers. This is largely
copied from hci_ldisc.c and modified to use serdev calls. There's a little
bit of duplication, but I avoided intermixing this as the ldisc code should
eventually go away.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Acked-by: Pavel Machek <pavel@ucw.cz>
[Fix style issues reported by Pavel]
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
(cherry picked from commit 82f5169bf3d3b5d8f7f7c437d2d83435173cb638)
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
---
 drivers/bluetooth/Makefile     |   1 +
 drivers/bluetooth/hci_serdev.c | 361 +++++++++++++++++++++++++++++++++
 drivers/bluetooth/hci_uart.h   |   4 +
 3 files changed, 366 insertions(+)
 create mode 100644 drivers/bluetooth/hci_serdev.c

Comments

Tyler Hicks Aug. 12, 2019, 11:41 p.m. UTC | #1
On 2019-08-12 16:08:43, Connor Kuehl wrote:
> From: Rob Herring <robh@kernel.org>
> 
> CVE-2019-10207
> 
> This adds library functions for serdev based BT drivers. This is largely
> copied from hci_ldisc.c and modified to use serdev calls. There's a little
> bit of duplication, but I avoided intermixing this as the ldisc code should
> eventually go away.
> 
> Signed-off-by: Rob Herring <robh@kernel.org>
> Cc: Marcel Holtmann <marcel@holtmann.org>
> Cc: Gustavo Padovan <gustavo@padovan.org>
> Cc: Johan Hedberg <johan.hedberg@gmail.com>
> Cc: linux-bluetooth@vger.kernel.org
> Acked-by: Pavel Machek <pavel@ucw.cz>
> [Fix style issues reported by Pavel]
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
> (cherry picked from commit 82f5169bf3d3b5d8f7f7c437d2d83435173cb638)
> Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
> ---
>  drivers/bluetooth/Makefile     |   1 +
>  drivers/bluetooth/hci_serdev.c | 361 +++++++++++++++++++++++++++++++++
>  drivers/bluetooth/hci_uart.h   |   4 +
>  3 files changed, 366 insertions(+)
>  create mode 100644 drivers/bluetooth/hci_serdev.c
> 
> diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
> index 07c9cf381e5a..67f1987c4e97 100644
> --- a/drivers/bluetooth/Makefile
> +++ b/drivers/bluetooth/Makefile
> @@ -28,6 +28,7 @@ btmrvl-y			:= btmrvl_main.o
>  btmrvl-$(CONFIG_DEBUG_FS)	+= btmrvl_debugfs.o
>  
>  hci_uart-y				:= hci_ldisc.o
> +hci_uart-$(CONFIG_SERIAL_DEV_BUS)	+= hci_serdev.o
>  hci_uart-$(CONFIG_BT_HCIUART_H4)	+= hci_h4.o
>  hci_uart-$(CONFIG_BT_HCIUART_BCSP)	+= hci_bcsp.o
>  hci_uart-$(CONFIG_BT_HCIUART_LL)	+= hci_ll.o
> diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
> new file mode 100644
> index 000000000000..f5ccb2c7ef92
> --- /dev/null
> +++ b/drivers/bluetooth/hci_serdev.c
> @@ -0,0 +1,361 @@
> +/*
> + *  Bluetooth HCI serdev driver lib
> + *
> + *  Copyright (C) 2017  Linaro, Ltd., Rob Herring <robh@kernel.org>
> + *
> + *  Based on hci_ldisc.c:
> + *
> + *  Copyright (C) 2000-2001  Qualcomm Incorporated
> + *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
> + *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/types.h>
> +#include <linux/serdev.h>
> +#include <linux/skbuff.h>
> +
> +#include <net/bluetooth/bluetooth.h>
> +#include <net/bluetooth/hci_core.h>
> +
> +#include "hci_uart.h"
> +
> +struct serdev_device_ops hci_serdev_client_ops;
> +
> +static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
> +{
> +	struct hci_dev *hdev = hu->hdev;
> +
> +	/* Update HCI stat counters */
> +	switch (pkt_type) {
> +	case HCI_COMMAND_PKT:
> +		hdev->stat.cmd_tx++;
> +		break;
> +
> +	case HCI_ACLDATA_PKT:
> +		hdev->stat.acl_tx++;
> +		break;
> +
> +	case HCI_SCODATA_PKT:
> +		hdev->stat.sco_tx++;
> +		break;
> +	}
> +}
> +
> +static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
> +{
> +	struct sk_buff *skb = hu->tx_skb;
> +
> +	if (!skb)
> +		skb = hu->proto->dequeue(hu);
> +	else
> +		hu->tx_skb = NULL;
> +
> +	return skb;
> +}
> +
> +static void hci_uart_write_work(struct work_struct *work)
> +{
> +	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
> +	struct serdev_device *serdev = hu->serdev;
> +	struct hci_dev *hdev = hu->hdev;
> +	struct sk_buff *skb;
> +
> +	/* REVISIT:
> +	 * should we cope with bad skbs or ->write() returning an error value?
> +	 */
> +	do {
> +		clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
> +
> +		while ((skb = hci_uart_dequeue(hu))) {
> +			int len;
> +
> +			len = serdev_device_write_buf(serdev,
> +						      skb->data, skb->len);
> +			hdev->stat.byte_tx += len;
> +
> +			skb_pull(skb, len);
> +			if (skb->len) {
> +				hu->tx_skb = skb;
> +				break;
> +			}
> +
> +			hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
> +			kfree_skb(skb);
> +		}
> +	} while(test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
> +
> +	clear_bit(HCI_UART_SENDING, &hu->tx_state);
> +}
> +
> +/* ------- Interface to HCI layer ------ */
> +
> +/* Initialize device */
> +static int hci_uart_open(struct hci_dev *hdev)
> +{
> +	struct hci_uart *hu  = hci_get_drvdata(hdev);
> +
> +	BT_DBG("%s %p", hdev->name, hdev);
> +
> +	serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
> +
> +	return serdev_device_open(hu->serdev);
> +}
> +
> +/* Reset device */
> +static int hci_uart_flush(struct hci_dev *hdev)
> +{
> +	struct hci_uart *hu  = hci_get_drvdata(hdev);
> +
> +	BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
> +
> +	if (hu->tx_skb) {
> +		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
> +	}
> +
> +	/* Flush any pending characters in the driver and discipline. */
> +	serdev_device_write_flush(hu->serdev);
> +
> +	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
> +		hu->proto->flush(hu);
> +
> +	return 0;
> +}
> +
> +/* Close device */
> +static int hci_uart_close(struct hci_dev *hdev)
> +{
> +	struct hci_uart *hu  = hci_get_drvdata(hdev);
> +
> +	BT_DBG("hdev %p", hdev);
> +
> +	hci_uart_flush(hdev);
> +	hdev->flush = NULL;
> +
> +	serdev_device_close(hu->serdev);
> +
> +	return 0;
> +}
> +
> +/* Send frames from HCI layer */
> +static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> +	struct hci_uart *hu = hci_get_drvdata(hdev);
> +
> +	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
> +	       skb->len);
> +
> +	hu->proto->enqueue(hu, skb);
> +
> +	hci_uart_tx_wakeup(hu);
> +
> +	return 0;
> +}
> +
> +static int hci_uart_setup(struct hci_dev *hdev)
> +{
> +	struct hci_uart *hu = hci_get_drvdata(hdev);
> +	struct hci_rp_read_local_version *ver;
> +	struct sk_buff *skb;
> +	unsigned int speed;
> +	int err;
> +
> +	/* Init speed if any */
> +	if (hu->init_speed)
> +		speed = hu->init_speed;
> +	else if (hu->proto->init_speed)
> +		speed = hu->proto->init_speed;
> +	else
> +		speed = 0;
> +
> +	if (speed)
> +		serdev_device_set_baudrate(hu->serdev, speed);
> +
> +	/* Operational speed if any */
> +	if (hu->oper_speed)
> +		speed = hu->oper_speed;
> +	else if (hu->proto->oper_speed)
> +		speed = hu->proto->oper_speed;
> +	else
> +		speed = 0;
> +
> +	if (hu->proto->set_baudrate && speed) {
> +		err = hu->proto->set_baudrate(hu, speed);
> +		if (err)
> +			BT_ERR("%s: failed to set baudrate", hdev->name);
> +		else
> +			serdev_device_set_baudrate(hu->serdev, speed);
> +	}
> +
> +	if (hu->proto->setup)
> +		return hu->proto->setup(hu);
> +
> +	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
> +		return 0;
> +
> +	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
> +			     HCI_INIT_TIMEOUT);
> +	if (IS_ERR(skb)) {
> +		BT_ERR("%s: Reading local version information failed (%ld)",
> +		       hdev->name, PTR_ERR(skb));
> +		return 0;
> +	}
> +
> +	if (skb->len != sizeof(*ver)) {
> +		BT_ERR("%s: Event length mismatch for version information",
> +		       hdev->name);
> +	}
> +
> +	kfree_skb(skb);
> +	return 0;
> +}
> +
> +/** hci_uart_write_wakeup - transmit buffer wakeup
> + * @serdev: serial device
> + *
> + * This function is called by the serdev framework when it accepts
> + * more data being sent.
> + */
> +static void hci_uart_write_wakeup(struct serdev_device *serdev)
> +{
> +	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
> +
> +	BT_DBG("");
> +
> +	if (!hu || serdev != hu->serdev) {
> +		WARN_ON(1);
> +		return;
> +	}
> +
> +	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
> +		hci_uart_tx_wakeup(hu);
> +}
> +
> +/** hci_uart_receive_buf - receive buffer wakeup
> + * @serdev: serial device
> + * @data:   pointer to received data
> + * @count:  count of received data in bytes
> + *
> + * This function is called by the serdev framework when it received data
> + * in the RX buffer.
> + *
> + * Return: number of processed bytes
> + */
> +static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
> +				   size_t count)
> +{
> +	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
> +
> +	if (!hu || serdev != hu->serdev) {
> +		WARN_ON(1);
> +		return 0;
> +	}
> +
> +	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
> +		return 0;
> +
> +	/* It does not need a lock here as it is already protected by a mutex in
> +	 * tty caller
> +	 */
> +	hu->proto->recv(hu, data, count);
> +
> +	if (hu->hdev)
> +		hu->hdev->stat.byte_rx += count;
> +
> +	return count;
> +}
> +
> +struct serdev_device_ops hci_serdev_client_ops = {
> +	.receive_buf = hci_uart_receive_buf,
> +	.write_wakeup = hci_uart_write_wakeup,
> +};
> +
> +int hci_uart_register_device(struct hci_uart *hu,
> +			     const struct hci_uart_proto *p)
> +{
> +	int err;
> +	struct hci_dev *hdev;
> +
> +	BT_DBG("");
> +
> +	err = p->open(hu);
> +	if (err)
> +		return err;
> +
> +	hu->proto = p;
> +	set_bit(HCI_UART_PROTO_READY, &hu->flags);
> +
> +	/* Initialize and register HCI device */
> +	hdev = hci_alloc_dev();
> +	if (!hdev) {
> +		BT_ERR("Can't allocate HCI device");
> +		err = -ENOMEM;
> +		goto err_alloc;
> +	}
> +
> +	hu->hdev = hdev;
> +
> +	hdev->bus = HCI_UART;
> +	hci_set_drvdata(hdev, hu);
> +
> +	INIT_WORK(&hu->write_work, hci_uart_write_work);
> +
> +	/* Only when vendor specific setup callback is provided, consider
> +	 * the manufacturer information valid. This avoids filling in the
> +	 * value for Ericsson when nothing is specified.
> +	 */
> +	if (hu->proto->setup)
> +		hdev->manufacturer = hu->proto->manufacturer;
> +
> +	hdev->open  = hci_uart_open;
> +	hdev->close = hci_uart_close;
> +	hdev->flush = hci_uart_flush;
> +	hdev->send  = hci_uart_send_frame;
> +	hdev->setup = hci_uart_setup;
> +	SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
> +
> +	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
> +		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
> +
> +	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
> +		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
> +
> +	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
> +		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
> +
> +	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
> +		hdev->dev_type = HCI_AMP;
> +	else
> +		hdev->dev_type = HCI_PRIMARY;
> +
> +	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
> +		return 0;
> +
> +	if (hci_register_dev(hdev) < 0) {
> +		BT_ERR("Can't register HCI device");
> +		err = -ENODEV;
> +		goto err_register;
> +	}
> +
> +	set_bit(HCI_UART_REGISTERED, &hu->flags);
> +
> +	return 0;
> +
> +err_register:
> +	hci_free_dev(hdev);
> +err_alloc:
> +	clear_bit(HCI_UART_PROTO_READY, &hu->flags);
> +	p->close(hu);
> +	return err;
> +}
> diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
> index 82c92f1b65b4..168aaaa2e58c 100644
> --- a/drivers/bluetooth/hci_uart.h
> +++ b/drivers/bluetooth/hci_uart.h
> @@ -55,6 +55,7 @@
>  #define HCI_UART_VND_DETECT	5
>  
>  struct hci_uart;
> +struct serdev_device;
>  
>  struct hci_uart_proto {
>  	unsigned int id;
> @@ -74,6 +75,7 @@ struct hci_uart_proto {
>  
>  struct hci_uart {
>  	struct tty_struct	*tty;
> +	struct serdev_device	*serdev;

IIUC, you're wanting to bring this patch back to Xenial so that the
hci_uart_has_flow_control() function, which is added by the next patch,
works as expected. Here's the hunk of interest from the next patch:

=======================================================================
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 96bcec5598c2..8e4362361769 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -257,6 +257,19 @@ static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 	return 0;
 }
 
+/* Check the underlying device or tty has flow control support */
+bool hci_uart_has_flow_control(struct hci_uart *hu)
+{
+	/* serdev nodes check if the needed operations are present */
+	if (hu->serdev)
+		return true;
+
+	if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset)
+		return true;
+
+	return false;
+}
+
 /* Flow control or un-flow control the device */
 void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
 {
=======================================================================

The only dependence hci_uart_has_flow_control() has on this patch is
that it does a check on the serdev member of the hci_uart struct.
However, the serdev member wouldn't exist if we simply didn't apply this
patch. I think the better Xenial backport is to *not* bring back this
patch and to modify hci_uart_has_flow_control(), added by the next
patch, by dropping the check on hu->serdev.

Tyler

>  	struct hci_dev		*hdev;
>  	unsigned long		flags;
>  	unsigned long		hdev_flags;
> @@ -101,6 +103,8 @@ struct hci_uart {
>  
>  int hci_uart_register_proto(const struct hci_uart_proto *p);
>  int hci_uart_unregister_proto(const struct hci_uart_proto *p);
> +int hci_uart_register_device(struct hci_uart *hu, const struct hci_uart_proto *p);
> +
>  int hci_uart_tx_wakeup(struct hci_uart *hu);
>  int hci_uart_init_ready(struct hci_uart *hu);
>  void hci_uart_init_tty(struct hci_uart *hu);
> -- 
> 2.20.1
> 
> 
> -- 
> kernel-team mailing list
> kernel-team@lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team

Patch
diff mbox series

diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index 07c9cf381e5a..67f1987c4e97 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -28,6 +28,7 @@  btmrvl-y			:= btmrvl_main.o
 btmrvl-$(CONFIG_DEBUG_FS)	+= btmrvl_debugfs.o
 
 hci_uart-y				:= hci_ldisc.o
+hci_uart-$(CONFIG_SERIAL_DEV_BUS)	+= hci_serdev.o
 hci_uart-$(CONFIG_BT_HCIUART_H4)	+= hci_h4.o
 hci_uart-$(CONFIG_BT_HCIUART_BCSP)	+= hci_bcsp.o
 hci_uart-$(CONFIG_BT_HCIUART_LL)	+= hci_ll.o
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
new file mode 100644
index 000000000000..f5ccb2c7ef92
--- /dev/null
+++ b/drivers/bluetooth/hci_serdev.c
@@ -0,0 +1,361 @@ 
+/*
+ *  Bluetooth HCI serdev driver lib
+ *
+ *  Copyright (C) 2017  Linaro, Ltd., Rob Herring <robh@kernel.org>
+ *
+ *  Based on hci_ldisc.c:
+ *
+ *  Copyright (C) 2000-2001  Qualcomm Incorporated
+ *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
+ *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "hci_uart.h"
+
+struct serdev_device_ops hci_serdev_client_ops;
+
+static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
+{
+	struct hci_dev *hdev = hu->hdev;
+
+	/* Update HCI stat counters */
+	switch (pkt_type) {
+	case HCI_COMMAND_PKT:
+		hdev->stat.cmd_tx++;
+		break;
+
+	case HCI_ACLDATA_PKT:
+		hdev->stat.acl_tx++;
+		break;
+
+	case HCI_SCODATA_PKT:
+		hdev->stat.sco_tx++;
+		break;
+	}
+}
+
+static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
+{
+	struct sk_buff *skb = hu->tx_skb;
+
+	if (!skb)
+		skb = hu->proto->dequeue(hu);
+	else
+		hu->tx_skb = NULL;
+
+	return skb;
+}
+
+static void hci_uart_write_work(struct work_struct *work)
+{
+	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
+	struct serdev_device *serdev = hu->serdev;
+	struct hci_dev *hdev = hu->hdev;
+	struct sk_buff *skb;
+
+	/* REVISIT:
+	 * should we cope with bad skbs or ->write() returning an error value?
+	 */
+	do {
+		clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
+
+		while ((skb = hci_uart_dequeue(hu))) {
+			int len;
+
+			len = serdev_device_write_buf(serdev,
+						      skb->data, skb->len);
+			hdev->stat.byte_tx += len;
+
+			skb_pull(skb, len);
+			if (skb->len) {
+				hu->tx_skb = skb;
+				break;
+			}
+
+			hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
+			kfree_skb(skb);
+		}
+	} while(test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
+
+	clear_bit(HCI_UART_SENDING, &hu->tx_state);
+}
+
+/* ------- Interface to HCI layer ------ */
+
+/* Initialize device */
+static int hci_uart_open(struct hci_dev *hdev)
+{
+	struct hci_uart *hu  = hci_get_drvdata(hdev);
+
+	BT_DBG("%s %p", hdev->name, hdev);
+
+	serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
+
+	return serdev_device_open(hu->serdev);
+}
+
+/* Reset device */
+static int hci_uart_flush(struct hci_dev *hdev)
+{
+	struct hci_uart *hu  = hci_get_drvdata(hdev);
+
+	BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
+
+	if (hu->tx_skb) {
+		kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
+	}
+
+	/* Flush any pending characters in the driver and discipline. */
+	serdev_device_write_flush(hu->serdev);
+
+	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
+		hu->proto->flush(hu);
+
+	return 0;
+}
+
+/* Close device */
+static int hci_uart_close(struct hci_dev *hdev)
+{
+	struct hci_uart *hu  = hci_get_drvdata(hdev);
+
+	BT_DBG("hdev %p", hdev);
+
+	hci_uart_flush(hdev);
+	hdev->flush = NULL;
+
+	serdev_device_close(hu->serdev);
+
+	return 0;
+}
+
+/* Send frames from HCI layer */
+static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+
+	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
+	       skb->len);
+
+	hu->proto->enqueue(hu, skb);
+
+	hci_uart_tx_wakeup(hu);
+
+	return 0;
+}
+
+static int hci_uart_setup(struct hci_dev *hdev)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+	struct hci_rp_read_local_version *ver;
+	struct sk_buff *skb;
+	unsigned int speed;
+	int err;
+
+	/* Init speed if any */
+	if (hu->init_speed)
+		speed = hu->init_speed;
+	else if (hu->proto->init_speed)
+		speed = hu->proto->init_speed;
+	else
+		speed = 0;
+
+	if (speed)
+		serdev_device_set_baudrate(hu->serdev, speed);
+
+	/* Operational speed if any */
+	if (hu->oper_speed)
+		speed = hu->oper_speed;
+	else if (hu->proto->oper_speed)
+		speed = hu->proto->oper_speed;
+	else
+		speed = 0;
+
+	if (hu->proto->set_baudrate && speed) {
+		err = hu->proto->set_baudrate(hu, speed);
+		if (err)
+			BT_ERR("%s: failed to set baudrate", hdev->name);
+		else
+			serdev_device_set_baudrate(hu->serdev, speed);
+	}
+
+	if (hu->proto->setup)
+		return hu->proto->setup(hu);
+
+	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
+		return 0;
+
+	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
+			     HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		BT_ERR("%s: Reading local version information failed (%ld)",
+		       hdev->name, PTR_ERR(skb));
+		return 0;
+	}
+
+	if (skb->len != sizeof(*ver)) {
+		BT_ERR("%s: Event length mismatch for version information",
+		       hdev->name);
+	}
+
+	kfree_skb(skb);
+	return 0;
+}
+
+/** hci_uart_write_wakeup - transmit buffer wakeup
+ * @serdev: serial device
+ *
+ * This function is called by the serdev framework when it accepts
+ * more data being sent.
+ */
+static void hci_uart_write_wakeup(struct serdev_device *serdev)
+{
+	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
+
+	BT_DBG("");
+
+	if (!hu || serdev != hu->serdev) {
+		WARN_ON(1);
+		return;
+	}
+
+	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
+		hci_uart_tx_wakeup(hu);
+}
+
+/** hci_uart_receive_buf - receive buffer wakeup
+ * @serdev: serial device
+ * @data:   pointer to received data
+ * @count:  count of received data in bytes
+ *
+ * This function is called by the serdev framework when it received data
+ * in the RX buffer.
+ *
+ * Return: number of processed bytes
+ */
+static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
+				   size_t count)
+{
+	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
+
+	if (!hu || serdev != hu->serdev) {
+		WARN_ON(1);
+		return 0;
+	}
+
+	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
+		return 0;
+
+	/* It does not need a lock here as it is already protected by a mutex in
+	 * tty caller
+	 */
+	hu->proto->recv(hu, data, count);
+
+	if (hu->hdev)
+		hu->hdev->stat.byte_rx += count;
+
+	return count;
+}
+
+struct serdev_device_ops hci_serdev_client_ops = {
+	.receive_buf = hci_uart_receive_buf,
+	.write_wakeup = hci_uart_write_wakeup,
+};
+
+int hci_uart_register_device(struct hci_uart *hu,
+			     const struct hci_uart_proto *p)
+{
+	int err;
+	struct hci_dev *hdev;
+
+	BT_DBG("");
+
+	err = p->open(hu);
+	if (err)
+		return err;
+
+	hu->proto = p;
+	set_bit(HCI_UART_PROTO_READY, &hu->flags);
+
+	/* Initialize and register HCI device */
+	hdev = hci_alloc_dev();
+	if (!hdev) {
+		BT_ERR("Can't allocate HCI device");
+		err = -ENOMEM;
+		goto err_alloc;
+	}
+
+	hu->hdev = hdev;
+
+	hdev->bus = HCI_UART;
+	hci_set_drvdata(hdev, hu);
+
+	INIT_WORK(&hu->write_work, hci_uart_write_work);
+
+	/* Only when vendor specific setup callback is provided, consider
+	 * the manufacturer information valid. This avoids filling in the
+	 * value for Ericsson when nothing is specified.
+	 */
+	if (hu->proto->setup)
+		hdev->manufacturer = hu->proto->manufacturer;
+
+	hdev->open  = hci_uart_open;
+	hdev->close = hci_uart_close;
+	hdev->flush = hci_uart_flush;
+	hdev->send  = hci_uart_send_frame;
+	hdev->setup = hci_uart_setup;
+	SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
+
+	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
+		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
+
+	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
+		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
+
+	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
+		set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
+
+	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
+		hdev->dev_type = HCI_AMP;
+	else
+		hdev->dev_type = HCI_PRIMARY;
+
+	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
+		return 0;
+
+	if (hci_register_dev(hdev) < 0) {
+		BT_ERR("Can't register HCI device");
+		err = -ENODEV;
+		goto err_register;
+	}
+
+	set_bit(HCI_UART_REGISTERED, &hu->flags);
+
+	return 0;
+
+err_register:
+	hci_free_dev(hdev);
+err_alloc:
+	clear_bit(HCI_UART_PROTO_READY, &hu->flags);
+	p->close(hu);
+	return err;
+}
diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index 82c92f1b65b4..168aaaa2e58c 100644
--- a/drivers/bluetooth/hci_uart.h
+++ b/drivers/bluetooth/hci_uart.h
@@ -55,6 +55,7 @@ 
 #define HCI_UART_VND_DETECT	5
 
 struct hci_uart;
+struct serdev_device;
 
 struct hci_uart_proto {
 	unsigned int id;
@@ -74,6 +75,7 @@  struct hci_uart_proto {
 
 struct hci_uart {
 	struct tty_struct	*tty;
+	struct serdev_device	*serdev;
 	struct hci_dev		*hdev;
 	unsigned long		flags;
 	unsigned long		hdev_flags;
@@ -101,6 +103,8 @@  struct hci_uart {
 
 int hci_uart_register_proto(const struct hci_uart_proto *p);
 int hci_uart_unregister_proto(const struct hci_uart_proto *p);
+int hci_uart_register_device(struct hci_uart *hu, const struct hci_uart_proto *p);
+
 int hci_uart_tx_wakeup(struct hci_uart *hu);
 int hci_uart_init_ready(struct hci_uart *hu);
 void hci_uart_init_tty(struct hci_uart *hu);