Commit 82f5169b authored by Rob Herring's avatar Rob Herring Committed by Marcel Holtmann
Browse files

Bluetooth: hci_uart: add serdev driver support library 



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: default avatarRob 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: default avatarPavel Machek <pavel@ucw.cz>
[Fix style issues reported by Pavel]
Signed-off-by: default avatarSebastian Reichel <sre@kernel.org>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent aeac3014

drivers/bluetooth/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 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

drivers/bluetooth/hci_serdev.c

0 → 100644
+361 −0
Original line number Diff line number Diff line 
/*

 *  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;

}

drivers/bluetooth/hci_uart.h

+4 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ 
#define HCI_UART_VND_DETECT	5



struct hci_uart;

struct serdev_device;



struct hci_uart_proto {

	unsigned int id;
@@ -77,6 +78,7 @@ 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;
@@ -108,6 +110,8 @@ 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);

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