[mirror_ubuntu-bionic-kernel.git] / drivers / bluetooth / hci_serdev.c

/*
 *  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"

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)
		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)
{
	BT_DBG("%s %p", hdev->name, hdev);

	return 0;
}

/* 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)
{
	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 = 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);
	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_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;
}
EXPORT_SYMBOL_GPL(hci_uart_register_device);

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

	hci_unregister_dev(hdev);
	hci_free_dev(hdev);

	cancel_work_sync(&hu->write_work);

	hu->proto->close(hu);
}
EXPORT_SYMBOL_GPL(hci_uart_unregister_device);
Commit	Line	Data
82f5169b RH	1	/*
	2	* Bluetooth HCI serdev driver lib
	3	*
	4	* Copyright (C) 2017 Linaro, Ltd., Rob Herring <robh@kernel.org>
	5	*
	6	* Based on hci_ldisc.c:
	7	*
	8	* Copyright (C) 2000-2001 Qualcomm Incorporated
	9	* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
	10	* Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2 of the License, or
	15	* (at your option) any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	* GNU General Public License for more details.
	21	*
	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/types.h>
	26	#include <linux/serdev.h>
	27	#include <linux/skbuff.h>
	28
	29	#include <net/bluetooth/bluetooth.h>
	30	#include <net/bluetooth/hci_core.h>
	31
	32	#include "hci_uart.h"
	33
640e32c9	34	static struct serdev_device_ops hci_serdev_client_ops;
82f5169b RH	35
	36	static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
	37	{
	38	struct hci_dev *hdev = hu->hdev;
	39
	40	/* Update HCI stat counters */
	41	switch (pkt_type) {
	42	case HCI_COMMAND_PKT:
	43	hdev->stat.cmd_tx++;
	44	break;
	45
	46	case HCI_ACLDATA_PKT:
	47	hdev->stat.acl_tx++;
	48	break;
	49
	50	case HCI_SCODATA_PKT:
	51	hdev->stat.sco_tx++;
	52	break;
	53	}
	54	}
	55
	56	static inline struct sk_buff hci_uart_dequeue(struct hci_uart hu)
	57	{
	58	struct sk_buff *skb = hu->tx_skb;
	59
	60	if (!skb)
	61	skb = hu->proto->dequeue(hu);
	62	else
	63	hu->tx_skb = NULL;
	64
	65	return skb;
	66	}
	67
	68	static void hci_uart_write_work(struct work_struct *work)
	69	{
	70	struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
	71	struct serdev_device *serdev = hu->serdev;
	72	struct hci_dev *hdev = hu->hdev;
	73	struct sk_buff *skb;
	74
	75	/* REVISIT:
	76	* should we cope with bad skbs or ->write() returning an error value?
	77	*/
	78	do {
	79	clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
	80
	81	while ((skb = hci_uart_dequeue(hu))) {
	82	int len;
	83
	84	len = serdev_device_write_buf(serdev,
	85	skb->data, skb->len);
	86	hdev->stat.byte_tx += len;
	87
	88	skb_pull(skb, len);
	89	if (skb->len) {
	90	hu->tx_skb = skb;
	91	break;
	92	}
	93
	94	hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
	95	kfree_skb(skb);
	96	}
	97	} while(test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
	98
99	clear_bit(HCI_UART_SENDING, &hu->tx_state);
100	}
101
102	/* ------- Interface to HCI layer ------ */
103
104	/* Initialize device */
105	static int hci_uart_open(struct hci_dev *hdev)
106	{
82f5169b RH	107	BT_DBG("%s %p", hdev->name, hdev);
82f5169b RH	108
52b318e6	109	return 0;
82f5169b RH	110	}
	111
	112	/* Reset device */
	113	static int hci_uart_flush(struct hci_dev *hdev)
	114	{
	115	struct hci_uart *hu = hci_get_drvdata(hdev);
	116
	117	BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
	118
	119	if (hu->tx_skb) {
	120	kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
	121	}
	122
	123	/* Flush any pending characters in the driver and discipline. */
	124	serdev_device_write_flush(hu->serdev);
	125
	126	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
	127	hu->proto->flush(hu);
	128
	129	return 0;
	130	}
	131
	132	/* Close device */
	133	static int hci_uart_close(struct hci_dev *hdev)
	134	{
82f5169b RH	135	BT_DBG("hdev %p", hdev);
	136
	137	hci_uart_flush(hdev);
	138	hdev->flush = NULL;
	139
82f5169b RH	140	return 0;
	141	}
	142
	143	/* Send frames from HCI layer */
	144	static int hci_uart_send_frame(struct hci_dev hdev, struct sk_buff skb)
	145	{
	146	struct hci_uart *hu = hci_get_drvdata(hdev);
	147
	148	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
	149	skb->len);
	150
	151	hu->proto->enqueue(hu, skb);
	152
	153	hci_uart_tx_wakeup(hu);
	154
	155	return 0;
	156	}
	157
	158	static int hci_uart_setup(struct hci_dev *hdev)
	159	{
	160	struct hci_uart *hu = hci_get_drvdata(hdev);
	161	struct hci_rp_read_local_version *ver;
	162	struct sk_buff *skb;
	163	unsigned int speed;
	164	int err;
	165
	166	/* Init speed if any */
	167	if (hu->init_speed)
	168	speed = hu->init_speed;
	169	else if (hu->proto->init_speed)
	170	speed = hu->proto->init_speed;
	171	else
	172	speed = 0;
	173
	174	if (speed)
	175	serdev_device_set_baudrate(hu->serdev, speed);
	176
	177	/* Operational speed if any */
	178	if (hu->oper_speed)
	179	speed = hu->oper_speed;
	180	else if (hu->proto->oper_speed)
	181	speed = hu->proto->oper_speed;
	182	else
	183	speed = 0;
	184
	185	if (hu->proto->set_baudrate && speed) {
	186	err = hu->proto->set_baudrate(hu, speed);
	187	if (err)
2064ee33	188	bt_dev_err(hdev, "Failed to set baudrate");
82f5169b RH	189	else
	190	serdev_device_set_baudrate(hu->serdev, speed);
	191	}
	192
	193	if (hu->proto->setup)
	194	return hu->proto->setup(hu);
	195
	196	if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
	197	return 0;
	198
	199	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
	200	HCI_INIT_TIMEOUT);
	201	if (IS_ERR(skb)) {
2064ee33 MH	202	bt_dev_err(hdev, "Reading local version info failed (%ld)",
2064ee33 MH	203	PTR_ERR(skb));
82f5169b RH	204	return 0;
	205	}
	206
	207	if (skb->len != sizeof(*ver)) {
2064ee33	208	bt_dev_err(hdev, "Event length mismatch for version info");
82f5169b RH	209	}
	210
	211	kfree_skb(skb);
	212	return 0;
	213	}
	214
	215	/** hci_uart_write_wakeup - transmit buffer wakeup
	216	* @serdev: serial device
	217	*
	218	* This function is called by the serdev framework when it accepts
	219	* more data being sent.
	220	*/
	221	static void hci_uart_write_wakeup(struct serdev_device *serdev)
	222	{
	223	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
	224
	225	BT_DBG("");
	226
	227	if (!hu \|\| serdev != hu->serdev) {
	228	WARN_ON(1);
	229	return;
	230	}
	231
	232	if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
	233	hci_uart_tx_wakeup(hu);
	234	}
	235
	236	/** hci_uart_receive_buf - receive buffer wakeup
	237	* @serdev: serial device
	238	* @data: pointer to received data
	239	* @count: count of received data in bytes
	240	*
	241	* This function is called by the serdev framework when it received data
	242	* in the RX buffer.
	243	*
	244	* Return: number of processed bytes
	245	*/
	246	static int hci_uart_receive_buf(struct serdev_device serdev, const u8 data,
	247	size_t count)
	248	{
	249	struct hci_uart *hu = serdev_device_get_drvdata(serdev);
	250
	251	if (!hu \|\| serdev != hu->serdev) {
	252	WARN_ON(1);
	253	return 0;
	254	}
	255
	256	if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
	257	return 0;
	258
	259	/* It does not need a lock here as it is already protected by a mutex in
	260	* tty caller
	261	*/
	262	hu->proto->recv(hu, data, count);
	263
	264	if (hu->hdev)
	265	hu->hdev->stat.byte_rx += count;
	266
	267	return count;
	268	}
	269
640e32c9	270	static struct serdev_device_ops hci_serdev_client_ops = {
82f5169b RH	271	.receive_buf = hci_uart_receive_buf,
	272	.write_wakeup = hci_uart_write_wakeup,
	273	};
	274
	275	int hci_uart_register_device(struct hci_uart *hu,
	276	const struct hci_uart_proto *p)
	277	{
	278	int err;
	279	struct hci_dev *hdev;
	280
	281	BT_DBG("");
	282
52b318e6 SR	283	serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
52b318e6 SR	284
82f5169b RH	285	err = p->open(hu);
	286	if (err)
	287	return err;
	288
	289	hu->proto = p;
	290	set_bit(HCI_UART_PROTO_READY, &hu->flags);
	291
	292	/* Initialize and register HCI device */
	293	hdev = hci_alloc_dev();
	294	if (!hdev) {
	295	BT_ERR("Can't allocate HCI device");
	296	err = -ENOMEM;
	297	goto err_alloc;
	298	}
	299
	300	hu->hdev = hdev;
	301
	302	hdev->bus = HCI_UART;
	303	hci_set_drvdata(hdev, hu);
	304
	305	INIT_WORK(&hu->write_work, hci_uart_write_work);
2d025b5d	306	percpu_init_rwsem(&hu->proto_lock);
82f5169b RH	307
	308	/* Only when vendor specific setup callback is provided, consider
	309	* the manufacturer information valid. This avoids filling in the
	310	* value for Ericsson when nothing is specified.
	311	*/
	312	if (hu->proto->setup)
	313	hdev->manufacturer = hu->proto->manufacturer;
	314
	315	hdev->open = hci_uart_open;
	316	hdev->close = hci_uart_close;
	317	hdev->flush = hci_uart_flush;
	318	hdev->send = hci_uart_send_frame;
	319	hdev->setup = hci_uart_setup;
	320	SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
	321
	322	if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
	323	set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
	324
	325	if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
	326	set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
	327
	328	if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
	329	set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
	330
	331	if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
	332	hdev->dev_type = HCI_AMP;
	333	else
	334	hdev->dev_type = HCI_PRIMARY;
	335
	336	if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
	337	return 0;
	338
	339	if (hci_register_dev(hdev) < 0) {
	340	BT_ERR("Can't register HCI device");
	341	err = -ENODEV;
	342	goto err_register;
	343	}
	344
	345	set_bit(HCI_UART_REGISTERED, &hu->flags);
	346
	347	return 0;
	348
	349	err_register:
	350	hci_free_dev(hdev);
	351	err_alloc:
	352	clear_bit(HCI_UART_PROTO_READY, &hu->flags);
	353	p->close(hu);
	354	return err;
	355	}
081f36a8	356	EXPORT_SYMBOL_GPL(hci_uart_register_device);
c34dc3bf IM	357
	358	void hci_uart_unregister_device(struct hci_uart *hu)
	359	{
	360	struct hci_dev *hdev = hu->hdev;
	361
	362	hci_unregister_dev(hdev);
	363	hci_free_dev(hdev);
	364
	365	cancel_work_sync(&hu->write_work);
	366
	367	hu->proto->close(hu);
	368	}
	369	EXPORT_SYMBOL_GPL(hci_uart_unregister_device);