drivers/bluetooth/hci_serdev.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  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>
  */

 #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"

 static 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) {
 		if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
 			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);
 		}

 		clear_bit(HCI_UART_SENDING, &hu->tx_state);
 	} while (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
 }

 /* ------- Interface to HCI layer ------ */

 /* 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;
 }

 /* Initialize device */
 static int hci_uart_open(struct hci_dev *hdev)
 {
 	BT_DBG("%s %p", hdev->name, hdev);

 	/* Undo clearing this from hci_uart_close() */
 	hdev->flush = hci_uart_flush;

 	return 0;
 }

 /* Close device */
 static int hci_uart_close(struct hci_dev *hdev)
 {
 	BT_DBG("hdev %p", hdev);

 	hci_uart_flush(hdev);
 	hdev->flush = NULL;

 	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_dev_err(hdev, "Failed to set baudrate");
 		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_dev_err(hdev, "Reading local version info failed (%ld)",
 			   PTR_ERR(skb));
 		return 0;
 	}

 	if (skb->len != sizeof(*ver))
 		bt_dev_err(hdev, "Event length mismatch for version info");

 	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;
 }

 static 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("");

 	serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);

 	err = serdev_device_open(hu->serdev);
 	if (err)
 		return err;

 	err = p->open(hu);
 	if (err)
 		goto err_open;

 	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->init_ready, hci_uart_init_work);
 	INIT_WORK(&hu->write_work, hci_uart_write_work);
 	percpu_init_rwsem(&hu->proto_lock);

 	/* 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_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);
 err_open:
 	serdev_device_close(hu->serdev);
 	return err;
 }
 EXPORT_SYMBOL_GPL(hci_uart_register_device);

 void hci_uart_unregister_device(struct hci_uart *hu)
 {
 	struct hci_dev *hdev = hu->hdev;

 	clear_bit(HCI_UART_PROTO_READY, &hu->flags);

 	cancel_work_sync(&hu->init_ready);
 	if (test_bit(HCI_UART_REGISTERED, &hu->flags))
 		hci_unregister_dev(hdev);
 	hci_free_dev(hdev);

 	cancel_work_sync(&hu->write_work);

 	hu->proto->close(hu);
 	serdev_device_close(hu->serdev);
 }
 EXPORT_SYMBOL_GPL(hci_uart_unregister_device);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* 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>
	*/

	#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"

	static 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) {
	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
	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);
	}

	clear_bit(HCI_UART_SENDING, &hu->tx_state);
	} while (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
	}

	/* ------- Interface to HCI layer ------ */

	/* 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;
	}

	/* Initialize device */
	static int hci_uart_open(struct hci_dev *hdev)
	{
	BT_DBG("%s %p", hdev->name, hdev);

	/* Undo clearing this from hci_uart_close() */
	hdev->flush = hci_uart_flush;

	return 0;
	}

	/* Close device */
	static int hci_uart_close(struct hci_dev *hdev)
	{
	BT_DBG("hdev %p", hdev);

	hci_uart_flush(hdev);
	hdev->flush = NULL;

	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_dev_err(hdev, "Failed to set baudrate");
	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_dev_err(hdev, "Reading local version info failed (%ld)",
	PTR_ERR(skb));
	return 0;
	}

	if (skb->len != sizeof(*ver))
	bt_dev_err(hdev, "Event length mismatch for version info");

	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;
	}

	static 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("");

	serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);

	err = serdev_device_open(hu->serdev);
	if (err)
	return err;

	err = p->open(hu);
	if (err)
	goto err_open;

	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->init_ready, hci_uart_init_work);
	INIT_WORK(&hu->write_work, hci_uart_write_work);
	percpu_init_rwsem(&hu->proto_lock);

	/* 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_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);
	err_open:
	serdev_device_close(hu->serdev);
	return err;
	}
	EXPORT_SYMBOL_GPL(hci_uart_register_device);

	void hci_uart_unregister_device(struct hci_uart *hu)
	{
	struct hci_dev *hdev = hu->hdev;

	clear_bit(HCI_UART_PROTO_READY, &hu->flags);

	cancel_work_sync(&hu->init_ready);
	if (test_bit(HCI_UART_REGISTERED, &hu->flags))
	hci_unregister_dev(hdev);
	hci_free_dev(hdev);

	cancel_work_sync(&hu->write_work);

	hu->proto->close(hu);
	serdev_device_close(hu->serdev);
	}
	EXPORT_SYMBOL_GPL(hci_uart_unregister_device);