drivers/bluetooth/hci_smd.c - fp2-dev/kernel/msm - Gitiles

 /*
  *  HCI_SMD (HCI Shared Memory Driver) is Qualcomm's Shared memory driver
  *  for the BT HCI protocol.
  *
  *  Copyright (c) 2000-2001, 2011 Code Aurora Forum. All rights reserved.
  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
  *  Copyright (C) 2004-2006  Marcel Holtmann <marcel@holtmann.org>
  *
  *  This file is based on drivers/bluetooth/hci_vhci.c
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation
  *
  *  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/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/skbuff.h>
 #include <linux/wakelock.h>
 #include <linux/uaccess.h>
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
 #include <net/bluetooth/hci.h>
 #include <mach/msm_smd.h>

 #define EVENT_CHANNEL		"APPS_RIVA_BT_CMD"
 #define DATA_CHANNEL		"APPS_RIVA_BT_ACL"
 #define RX_Q_MONITOR		(1)	/* 1 milli second */


 static unsigned int driver_state;

 static int hcismd_set;
 static DEFINE_MUTEX(hci_smd_enable);

 static int hcismd_set_enable(const char *val, struct kernel_param *kp);
 module_param_call(hcismd_set, hcismd_set_enable, NULL, &hcismd_set, 0644);


 struct hci_smd_data {
 	struct hci_dev *hdev;

 	struct smd_channel *event_channel;
 	struct smd_channel *data_channel;
 	struct wake_lock wake_lock_tx;
 	struct wake_lock wake_lock_rx;
 	struct timer_list rx_q_timer;
 	struct tasklet_struct hci_event_task;
 	struct tasklet_struct hci_data_task;
 };
 static struct hci_smd_data hs;

 /* Rx queue monitor timer function */
 static int is_rx_q_empty(unsigned long arg)
 {
 	struct hci_dev *hdev = (struct hci_dev *) arg;
 	struct sk_buff_head *list_ = &hdev->rx_q;
 	struct sk_buff *list = ((struct sk_buff *)list_)->next;
 	BT_DBG("%s Rx timer triggered", hdev->name);

 	if (list == (struct sk_buff *)list_) {
 		BT_DBG("%s RX queue empty", hdev->name);
 		return 1;
 	} else{
 		BT_DBG("%s RX queue not empty", hdev->name);
 		return 0;
 	}
 }

 static void release_lock(void)
 {
 	struct hci_smd_data *hsmd = &hs;
 	BT_DBG("Releasing Rx Lock");
 	if (is_rx_q_empty((unsigned long)hsmd->hdev) &&
 		wake_lock_active(&hs.wake_lock_rx))
 			wake_unlock(&hs.wake_lock_rx);
 }

 /* Rx timer callback function */
 static void schedule_timer(unsigned long arg)
 {
 	struct hci_dev *hdev = (struct hci_dev *) arg;
 	struct hci_smd_data *hsmd = &hs;
 	BT_DBG("%s Schedule Rx timer", hdev->name);

 	if (is_rx_q_empty(arg) && wake_lock_active(&hs.wake_lock_rx)) {
 		BT_DBG("%s RX queue empty", hdev->name);
 		/*
 		 * Since the queue is empty, its ideal
 		 * to release the wake lock on Rx
 		 */
 		wake_unlock(&hs.wake_lock_rx);
 	} else{
 		BT_DBG("%s RX queue not empty", hdev->name);
 		/*
 		 * Restart the timer to monitor whether the Rx queue is
 		 * empty for releasing the Rx wake lock
 		 */
 		mod_timer(&hsmd->rx_q_timer,
 			jiffies + msecs_to_jiffies(RX_Q_MONITOR));
 	}
 }

 static int hci_smd_open(struct hci_dev *hdev)
 {
 	set_bit(HCI_RUNNING, &hdev->flags);
 	return 0;
 }


 static int hci_smd_close(struct hci_dev *hdev)
 {
 	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
 		return 0;
 	else
 		return -EPERM;
 }


 static void hci_smd_destruct(struct hci_dev *hdev)
 {
 	kfree(hdev->driver_data);
 }

 static void hci_smd_recv_data(unsigned long arg)
 {
 	int len = 0;
 	int rc = 0;
 	struct sk_buff *skb = NULL;
 	unsigned  char *buf = NULL;
 	struct hci_smd_data *hsmd = &hs;
 	wake_lock(&hs.wake_lock_rx);

 	len = smd_read_avail(hsmd->data_channel);
 	if (len > HCI_MAX_FRAME_SIZE) {
 		BT_ERR("Frame larger than the allowed size");
 		goto out_data;
 	}
 	while (len > 0) {
 		skb = bt_skb_alloc(len, GFP_ATOMIC);
 		if (!skb) {
 			BT_ERR("Error in allocating  socket buffer");
 			goto out_data;
 		}

 		buf = kmalloc(len, GFP_ATOMIC);
 		if (!buf)  {
 			BT_ERR("Error in allocating  buffer");
 			rc = -ENOMEM;
 			goto out_data;
 		}

 		rc = smd_read(hsmd->data_channel, (void *)buf, len);
 		if (rc < len) {
 			BT_ERR("Error in reading from the channel");
 			goto out_data;
 		}

 		memcpy(skb_put(skb, len), buf, len);
 		skb->dev = (void *)hsmd->hdev;
 		bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;

 		skb_orphan(skb);

 		rc = hci_recv_frame(skb);
 		if (rc < 0) {
 			BT_ERR("Error in passing the packet to HCI Layer");
 			/*
 			 * skb is getting freed in hci_recv_frame, making it
 			 * to null to avoid multiple access
 			 */
 			skb = NULL;
 			goto out_data;
 		}

 		kfree(buf);
 		buf = NULL;
 		len = smd_read_avail(hsmd->data_channel);
 		/*
 		 * Start the timer to monitor whether the Rx queue is
 		 * empty for releasing the Rx wake lock
 		 */
 		BT_DBG("Rx Timer is starting");
 		mod_timer(&hsmd->rx_q_timer,
 				jiffies + msecs_to_jiffies(RX_Q_MONITOR));
 	}
 out_data:
 	release_lock();
 	if (rc) {
 		if (skb)
 			kfree_skb(skb);
 		kfree(buf);
 	}
 }

 static void hci_smd_recv_event(unsigned long arg)
 {
 	int len = 0;
 	int rc = 0;
 	struct sk_buff *skb = NULL;
 	unsigned  char *buf = NULL;
 	struct hci_smd_data *hsmd = &hs;
 	wake_lock(&hs.wake_lock_rx);

 	len = smd_read_avail(hsmd->event_channel);
 	if (len > HCI_MAX_FRAME_SIZE) {
 		BT_ERR("Frame larger than the allowed size");
 		goto out_event;
 	}

 	while (len > 0) {
 		skb = bt_skb_alloc(len, GFP_ATOMIC);
 		if (!skb) {
 			BT_ERR("Error in allocating  socket buffer");
 			goto out_event;
 		}
 		buf = kmalloc(len, GFP_ATOMIC);
 		if (!buf) {
 			BT_ERR("Error in allocating  buffer");
 			rc = -ENOMEM;
 			goto out_event;
 		}
 		rc = smd_read(hsmd->event_channel, (void *)buf, len);
 		if (rc < len) {
 			BT_ERR("Error in reading from the event channel");
 			goto out_event;
 		}

 		memcpy(skb_put(skb, len), buf, len);
 		skb->dev = (void *)hsmd->hdev;
 		bt_cb(skb)->pkt_type = HCI_EVENT_PKT;

 		skb_orphan(skb);

 		rc = hci_recv_frame(skb);
 		if (rc < 0) {
 			BT_ERR("Error in passing the packet to HCI Layer");
 			/*
 			 * skb is getting freed in hci_recv_frame, making it
 			 *  to null to avoid multiple access
 			 */
 			skb = NULL;
 			goto out_event;
 		}

 		kfree(buf);
 		buf = NULL;
 		len = smd_read_avail(hsmd->event_channel);
 		/*
 		 * Start the timer to monitor whether the Rx queue is
 		 * empty for releasing the Rx wake lock
 		 */
 		BT_DBG("Rx Timer is starting");
 		mod_timer(&hsmd->rx_q_timer,
 				jiffies + msecs_to_jiffies(RX_Q_MONITOR));
 	}
 out_event:
 	release_lock();
 	if (rc) {
 		if (skb)
 			kfree_skb(skb);
 		kfree(buf);
 	}
 }

 static int hci_smd_send_frame(struct sk_buff *skb)
 {
 	int len;
 	int avail;
 	int ret = 0;
 	wake_lock(&hs.wake_lock_tx);

 	switch (bt_cb(skb)->pkt_type) {
 	case HCI_COMMAND_PKT:
 		avail = smd_write_avail(hs.event_channel);
 		if (!avail) {
 			BT_ERR("No space available for smd frame");
 			ret =  -ENOSPC;
 		}
 		len = smd_write(hs.event_channel, skb->data, skb->len);
 		if (len < skb->len) {
 			BT_ERR("Failed to write Command %d", len);
 			ret = -ENODEV;
 		}
 		break;
 	case HCI_ACLDATA_PKT:
 	case HCI_SCODATA_PKT:
 		avail = smd_write_avail(hs.data_channel);
 		if (!avail) {
 			BT_ERR("No space available for smd frame");
 			ret = -ENOSPC;
 		}
 		len = smd_write(hs.data_channel, skb->data, skb->len);
 		if (len < skb->len) {
 			BT_ERR("Failed to write Data %d", len);
 			ret = -ENODEV;
 		}
 		break;
 	default:
 		BT_ERR("Uknown packet type");
 		ret = -ENODEV;
 		break;
 	}

 	kfree_skb(skb);
 	wake_unlock(&hs.wake_lock_tx);
 	return ret;
 }


 static void hci_smd_notify_event(void *data, unsigned int event)
 {
 	struct hci_dev *hdev = hs.hdev;
 	struct hci_smd_data *hsmd = &hs;
 	int len = 0;

 	if (!hdev) {
 		BT_ERR("Frame for unknown HCI device (hdev=NULL)");
 		return;
 	}

 	switch (event) {
 	case SMD_EVENT_DATA:
 		len = smd_read_avail(hsmd->event_channel);
 		if (len > 0)
 			tasklet_hi_schedule(&hs.hci_event_task);
 		else if (len < 0)
 			BT_ERR("Failed to read event from smd %d", len);

 		break;
 	case SMD_EVENT_OPEN:
 		BT_INFO("opening HCI-SMD channel :%s", EVENT_CHANNEL);
 		hci_smd_open(hdev);
 		break;
 	case SMD_EVENT_CLOSE:
 		BT_INFO("Closing HCI-SMD channel :%s", EVENT_CHANNEL);
 		hci_smd_close(hdev);
 		break;
 	default:
 		break;
 	}
 }

 static void hci_smd_notify_data(void *data, unsigned int event)
 {
 	struct hci_dev *hdev = hs.hdev;
 	struct hci_smd_data *hsmd = &hs;
 	int len = 0;

 	if (!hdev) {
 		BT_ERR("HCI device (hdev=NULL)");
 		return;
 	}

 	switch (event) {
 	case SMD_EVENT_DATA:
 		len = smd_read_avail(hsmd->data_channel);
 		if (len > 0)
 			tasklet_hi_schedule(&hs.hci_data_task);
 		else if (len < 0)
 			BT_ERR("Failed to read data from smd %d", len);
 		break;
 	case SMD_EVENT_OPEN:
 		BT_INFO("opening HCI-SMD channel :%s", DATA_CHANNEL);
 		hci_smd_open(hdev);
 		break;
 	case SMD_EVENT_CLOSE:
 		BT_INFO("Closing HCI-SMD channel :%s", DATA_CHANNEL);
 		hci_smd_close(hdev);
 		break;
 	default:
 		break;
 	}

 }

 static int hci_smd_register_dev(struct hci_smd_data *hsmd)
 {
 	static struct hci_dev *hdev;
 	int rc;

 	/* Initialize and register HCI device */
 	if (!driver_state) {
 		hdev = hci_alloc_dev();
 		if (!hdev) {
 			BT_ERR("Can't allocate HCI device");
 			return -ENOMEM;
 		}

 		hsmd->hdev = hdev;
 		hdev->bus = HCI_SMD;
 		hdev->driver_data = hsmd;
 		hdev->open  = hci_smd_open;
 		hdev->close = hci_smd_close;
 		hdev->send  = hci_smd_send_frame;
 		hdev->destruct = hci_smd_destruct;
 		hdev->owner = THIS_MODULE;
 	}

 	tasklet_init(&hsmd->hci_event_task,
 			hci_smd_recv_event, (unsigned long) hsmd);
 	tasklet_init(&hsmd->hci_data_task,
 			hci_smd_recv_data, (unsigned long) hsmd);
 	if (!driver_state) {
 		wake_lock_init(&hs.wake_lock_rx, WAKE_LOCK_SUSPEND,
 				 "msm_smd_Rx");
 		wake_lock_init(&hs.wake_lock_tx, WAKE_LOCK_SUSPEND,
 				 "msm_smd_Tx");
 	}
 	/*
 	 * Setup the timer to monitor whether the Rx queue is empty,
 	 * to control the wake lock release
 	 */
 	setup_timer(&hsmd->rx_q_timer, schedule_timer,
 			(unsigned long) hsmd->hdev);

 	/* Open the SMD Channel and device and register the callback function */
 	rc = smd_named_open_on_edge(EVENT_CHANNEL, SMD_APPS_WCNSS,
 			&hsmd->event_channel, hdev, hci_smd_notify_event);
 	if (rc < 0) {
 		BT_ERR("Cannot open the command channel");
 		hci_free_dev(hdev);
 		return -ENODEV;
 	}

 	rc = smd_named_open_on_edge(DATA_CHANNEL, SMD_APPS_WCNSS,
 			&hsmd->data_channel, hdev, hci_smd_notify_data);
 	if (rc < 0) {
 		BT_ERR("Failed to open the Data channel");
 		hci_free_dev(hdev);
 		return -ENODEV;
 	}

 	/* Disable the read interrupts on the channel */
 	smd_disable_read_intr(hsmd->event_channel);
 	smd_disable_read_intr(hsmd->data_channel);
 	if (!driver_state) {
 		if (hci_register_dev(hdev) < 0) {
 			BT_ERR("Can't register HCI device");
 			hci_free_dev(hdev);
 			return -ENODEV;
 		}
 		driver_state = 1;
 	}
 	return 0;
 }

 static void hci_smd_deregister_dev(void)
 {
 	smd_close(hs.event_channel);
 	smd_close(hs.data_channel);

 	if (wake_lock_active(&hs.wake_lock_rx))
 		wake_unlock(&hs.wake_lock_rx);

 	/*Destroy the timer used to monitor the Rx queue for emptiness */
 	del_timer_sync(&hs.rx_q_timer);
 	tasklet_kill(&hs.hci_event_task);
 	tasklet_kill(&hs.hci_data_task);
 }

 static int hcismd_set_enable(const char *val, struct kernel_param *kp)
 {
 	int ret = 0;

 	mutex_lock(&hci_smd_enable);

 	ret = param_set_int(val, kp);

 	if (ret)
 		goto done;

 	switch (hcismd_set) {

 	case 1:
 		hci_smd_register_dev(&hs);
 	break;
 	case 0:
 		hci_smd_deregister_dev();
 	break;
 	default:
 		ret = -EFAULT;
 	}

 done:
 	mutex_unlock(&hci_smd_enable);
 	return ret;
 }


 MODULE_AUTHOR("Ankur Nandwani <ankurn@codeaurora.org>");
 MODULE_DESCRIPTION("Bluetooth SMD driver");
 MODULE_LICENSE("GPL v2");
	/*
	* HCI_SMD (HCI Shared Memory Driver) is Qualcomm's Shared memory driver
	* for the BT HCI protocol.
	*
	* Copyright (c) 2000-2001, 2011 Code Aurora Forum. All rights reserved.
	* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
	* Copyright (C) 2004-2006 Marcel Holtmann <marcel@holtmann.org>
	*
	* This file is based on drivers/bluetooth/hci_vhci.c
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2
	* as published by the Free Software Foundation
	*
	* 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/module.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/errno.h>
	#include <linux/string.h>
	#include <linux/skbuff.h>
	#include <linux/wakelock.h>
	#include <linux/uaccess.h>
	#include <net/bluetooth/bluetooth.h>
	#include <net/bluetooth/hci_core.h>
	#include <net/bluetooth/hci.h>
	#include <mach/msm_smd.h>

	#define EVENT_CHANNEL "APPS_RIVA_BT_CMD"
	#define DATA_CHANNEL "APPS_RIVA_BT_ACL"
	#define RX_Q_MONITOR (1) /* 1 milli second */


	static unsigned int driver_state;

	static int hcismd_set;
	static DEFINE_MUTEX(hci_smd_enable);

	static int hcismd_set_enable(const char val, struct kernel_param kp);
	module_param_call(hcismd_set, hcismd_set_enable, NULL, &hcismd_set, 0644);


	struct hci_smd_data {
	struct hci_dev *hdev;

	struct smd_channel *event_channel;
	struct smd_channel *data_channel;
	struct wake_lock wake_lock_tx;
	struct wake_lock wake_lock_rx;
	struct timer_list rx_q_timer;
	struct tasklet_struct hci_event_task;
	struct tasklet_struct hci_data_task;
	};
	static struct hci_smd_data hs;

	/* Rx queue monitor timer function */
	static int is_rx_q_empty(unsigned long arg)
	{
	struct hci_dev hdev = (struct hci_dev ) arg;
	struct sk_buff_head *list_ = &hdev->rx_q;
	struct sk_buff list = ((struct sk_buff )list_)->next;
	BT_DBG("%s Rx timer triggered", hdev->name);

	if (list == (struct sk_buff *)list_) {
	BT_DBG("%s RX queue empty", hdev->name);
	return 1;
	} else{
	BT_DBG("%s RX queue not empty", hdev->name);
	return 0;
	}
	}

	static void release_lock(void)
	{
	struct hci_smd_data *hsmd = &hs;
	BT_DBG("Releasing Rx Lock");
	if (is_rx_q_empty((unsigned long)hsmd->hdev) &&
	wake_lock_active(&hs.wake_lock_rx))
	wake_unlock(&hs.wake_lock_rx);
	}

	/* Rx timer callback function */
	static void schedule_timer(unsigned long arg)
	{
	struct hci_dev hdev = (struct hci_dev ) arg;
	struct hci_smd_data *hsmd = &hs;
	BT_DBG("%s Schedule Rx timer", hdev->name);

	if (is_rx_q_empty(arg) && wake_lock_active(&hs.wake_lock_rx)) {
	BT_DBG("%s RX queue empty", hdev->name);
	/*
	* Since the queue is empty, its ideal
	* to release the wake lock on Rx
	*/
	wake_unlock(&hs.wake_lock_rx);
	} else{
	BT_DBG("%s RX queue not empty", hdev->name);
	/*
	* Restart the timer to monitor whether the Rx queue is
	* empty for releasing the Rx wake lock
	*/
	mod_timer(&hsmd->rx_q_timer,
	jiffies + msecs_to_jiffies(RX_Q_MONITOR));
	}
	}

	static int hci_smd_open(struct hci_dev *hdev)
	{
	set_bit(HCI_RUNNING, &hdev->flags);
	return 0;
	}


	static int hci_smd_close(struct hci_dev *hdev)
	{
	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
	return 0;
	else
	return -EPERM;
	}


	static void hci_smd_destruct(struct hci_dev *hdev)
	{
	kfree(hdev->driver_data);
	}

	static void hci_smd_recv_data(unsigned long arg)
	{
	int len = 0;
	int rc = 0;
	struct sk_buff *skb = NULL;
	unsigned char *buf = NULL;
	struct hci_smd_data *hsmd = &hs;
	wake_lock(&hs.wake_lock_rx);

	len = smd_read_avail(hsmd->data_channel);
	if (len > HCI_MAX_FRAME_SIZE) {
	BT_ERR("Frame larger than the allowed size");
	goto out_data;
	}
	while (len > 0) {
	skb = bt_skb_alloc(len, GFP_ATOMIC);
	if (!skb) {
	BT_ERR("Error in allocating socket buffer");
	goto out_data;
	}

	buf = kmalloc(len, GFP_ATOMIC);
	if (!buf) {
	BT_ERR("Error in allocating buffer");
	rc = -ENOMEM;
	goto out_data;
	}

	rc = smd_read(hsmd->data_channel, (void *)buf, len);
	if (rc < len) {
	BT_ERR("Error in reading from the channel");
	goto out_data;
	}

	memcpy(skb_put(skb, len), buf, len);
	skb->dev = (void *)hsmd->hdev;
	bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;

	skb_orphan(skb);

	rc = hci_recv_frame(skb);
	if (rc < 0) {
	BT_ERR("Error in passing the packet to HCI Layer");
	/*
	* skb is getting freed in hci_recv_frame, making it
	* to null to avoid multiple access
	*/
	skb = NULL;
	goto out_data;
	}

	kfree(buf);
	buf = NULL;
	len = smd_read_avail(hsmd->data_channel);
	/*
	* Start the timer to monitor whether the Rx queue is
	* empty for releasing the Rx wake lock
	*/
	BT_DBG("Rx Timer is starting");
	mod_timer(&hsmd->rx_q_timer,
	jiffies + msecs_to_jiffies(RX_Q_MONITOR));
	}
	out_data:
	release_lock();
	if (rc) {
	if (skb)
	kfree_skb(skb);
	kfree(buf);
	}
	}

	static void hci_smd_recv_event(unsigned long arg)
	{
	int len = 0;
	int rc = 0;
	struct sk_buff *skb = NULL;
	unsigned char *buf = NULL;
	struct hci_smd_data *hsmd = &hs;
	wake_lock(&hs.wake_lock_rx);

	len = smd_read_avail(hsmd->event_channel);
	if (len > HCI_MAX_FRAME_SIZE) {
	BT_ERR("Frame larger than the allowed size");
	goto out_event;
	}

	while (len > 0) {
	skb = bt_skb_alloc(len, GFP_ATOMIC);
	if (!skb) {
	BT_ERR("Error in allocating socket buffer");
	goto out_event;
	}
	buf = kmalloc(len, GFP_ATOMIC);
	if (!buf) {
	BT_ERR("Error in allocating buffer");
	rc = -ENOMEM;
	goto out_event;
	}
	rc = smd_read(hsmd->event_channel, (void *)buf, len);
	if (rc < len) {
	BT_ERR("Error in reading from the event channel");
	goto out_event;
	}

	memcpy(skb_put(skb, len), buf, len);
	skb->dev = (void *)hsmd->hdev;
	bt_cb(skb)->pkt_type = HCI_EVENT_PKT;

	skb_orphan(skb);

	rc = hci_recv_frame(skb);
	if (rc < 0) {
	BT_ERR("Error in passing the packet to HCI Layer");
	/*
	* skb is getting freed in hci_recv_frame, making it
	* to null to avoid multiple access
	*/
	skb = NULL;
	goto out_event;
	}

	kfree(buf);
	buf = NULL;
	len = smd_read_avail(hsmd->event_channel);
	/*
	* Start the timer to monitor whether the Rx queue is
	* empty for releasing the Rx wake lock
	*/
	BT_DBG("Rx Timer is starting");
	mod_timer(&hsmd->rx_q_timer,
	jiffies + msecs_to_jiffies(RX_Q_MONITOR));
	}
	out_event:
	release_lock();
	if (rc) {
	if (skb)
	kfree_skb(skb);
	kfree(buf);
	}
	}

	static int hci_smd_send_frame(struct sk_buff *skb)
	{
	int len;
	int avail;
	int ret = 0;
	wake_lock(&hs.wake_lock_tx);

	switch (bt_cb(skb)->pkt_type) {
	case HCI_COMMAND_PKT:
	avail = smd_write_avail(hs.event_channel);
	if (!avail) {
	BT_ERR("No space available for smd frame");
	ret = -ENOSPC;
	}
	len = smd_write(hs.event_channel, skb->data, skb->len);
	if (len < skb->len) {
	BT_ERR("Failed to write Command %d", len);
	ret = -ENODEV;
	}
	break;
	case HCI_ACLDATA_PKT:
	case HCI_SCODATA_PKT:
	avail = smd_write_avail(hs.data_channel);
	if (!avail) {
	BT_ERR("No space available for smd frame");
	ret = -ENOSPC;
	}
	len = smd_write(hs.data_channel, skb->data, skb->len);
	if (len < skb->len) {
	BT_ERR("Failed to write Data %d", len);
	ret = -ENODEV;
	}
	break;
	default:
	BT_ERR("Uknown packet type");
	ret = -ENODEV;
	break;
	}

	kfree_skb(skb);
	wake_unlock(&hs.wake_lock_tx);
	return ret;
	}


	static void hci_smd_notify_event(void *data, unsigned int event)
	{
	struct hci_dev *hdev = hs.hdev;
	struct hci_smd_data *hsmd = &hs;
	int len = 0;

	if (!hdev) {
	BT_ERR("Frame for unknown HCI device (hdev=NULL)");
	return;
	}

	switch (event) {
	case SMD_EVENT_DATA:
	len = smd_read_avail(hsmd->event_channel);
	if (len > 0)
	tasklet_hi_schedule(&hs.hci_event_task);
	else if (len < 0)
	BT_ERR("Failed to read event from smd %d", len);

	break;
	case SMD_EVENT_OPEN:
	BT_INFO("opening HCI-SMD channel :%s", EVENT_CHANNEL);
	hci_smd_open(hdev);
	break;
	case SMD_EVENT_CLOSE:
	BT_INFO("Closing HCI-SMD channel :%s", EVENT_CHANNEL);
	hci_smd_close(hdev);
	break;
	default:
	break;
	}
	}

	static void hci_smd_notify_data(void *data, unsigned int event)
	{
	struct hci_dev *hdev = hs.hdev;
	struct hci_smd_data *hsmd = &hs;
	int len = 0;

	if (!hdev) {
	BT_ERR("HCI device (hdev=NULL)");
	return;
	}

	switch (event) {
	case SMD_EVENT_DATA:
	len = smd_read_avail(hsmd->data_channel);
	if (len > 0)
	tasklet_hi_schedule(&hs.hci_data_task);
	else if (len < 0)
	BT_ERR("Failed to read data from smd %d", len);
	break;
	case SMD_EVENT_OPEN:
	BT_INFO("opening HCI-SMD channel :%s", DATA_CHANNEL);
	hci_smd_open(hdev);
	break;
	case SMD_EVENT_CLOSE:
	BT_INFO("Closing HCI-SMD channel :%s", DATA_CHANNEL);
	hci_smd_close(hdev);
	break;
	default:
	break;
	}

	}

	static int hci_smd_register_dev(struct hci_smd_data *hsmd)
	{
	static struct hci_dev *hdev;
	int rc;

	/* Initialize and register HCI device */
	if (!driver_state) {
	hdev = hci_alloc_dev();
	if (!hdev) {
	BT_ERR("Can't allocate HCI device");
	return -ENOMEM;
	}

	hsmd->hdev = hdev;
	hdev->bus = HCI_SMD;
	hdev->driver_data = hsmd;
	hdev->open = hci_smd_open;
	hdev->close = hci_smd_close;
	hdev->send = hci_smd_send_frame;
	hdev->destruct = hci_smd_destruct;
	hdev->owner = THIS_MODULE;
	}

	tasklet_init(&hsmd->hci_event_task,
	hci_smd_recv_event, (unsigned long) hsmd);
	tasklet_init(&hsmd->hci_data_task,
	hci_smd_recv_data, (unsigned long) hsmd);
	if (!driver_state) {
	wake_lock_init(&hs.wake_lock_rx, WAKE_LOCK_SUSPEND,
	"msm_smd_Rx");
	wake_lock_init(&hs.wake_lock_tx, WAKE_LOCK_SUSPEND,
	"msm_smd_Tx");
	}
	/*
	* Setup the timer to monitor whether the Rx queue is empty,
	* to control the wake lock release
	*/
	setup_timer(&hsmd->rx_q_timer, schedule_timer,
	(unsigned long) hsmd->hdev);

	/* Open the SMD Channel and device and register the callback function */
	rc = smd_named_open_on_edge(EVENT_CHANNEL, SMD_APPS_WCNSS,
	&hsmd->event_channel, hdev, hci_smd_notify_event);
	if (rc < 0) {
	BT_ERR("Cannot open the command channel");
	hci_free_dev(hdev);
	return -ENODEV;
	}

	rc = smd_named_open_on_edge(DATA_CHANNEL, SMD_APPS_WCNSS,
	&hsmd->data_channel, hdev, hci_smd_notify_data);
	if (rc < 0) {
	BT_ERR("Failed to open the Data channel");
	hci_free_dev(hdev);
	return -ENODEV;
	}

	/* Disable the read interrupts on the channel */
	smd_disable_read_intr(hsmd->event_channel);
	smd_disable_read_intr(hsmd->data_channel);
	if (!driver_state) {
	if (hci_register_dev(hdev) < 0) {
	BT_ERR("Can't register HCI device");
	hci_free_dev(hdev);
	return -ENODEV;
	}
	driver_state = 1;
	}
	return 0;
	}

	static void hci_smd_deregister_dev(void)
	{
	smd_close(hs.event_channel);
	smd_close(hs.data_channel);

	if (wake_lock_active(&hs.wake_lock_rx))
	wake_unlock(&hs.wake_lock_rx);

	/Destroy the timer used to monitor the Rx queue for emptiness /
	del_timer_sync(&hs.rx_q_timer);
	tasklet_kill(&hs.hci_event_task);
	tasklet_kill(&hs.hci_data_task);
	}

	static int hcismd_set_enable(const char val, struct kernel_param kp)
	{
	int ret = 0;

	mutex_lock(&hci_smd_enable);

	ret = param_set_int(val, kp);

	if (ret)
	goto done;

	switch (hcismd_set) {

	case 1:
	hci_smd_register_dev(&hs);
	break;
	case 0:
	hci_smd_deregister_dev();
	break;
	default:
	ret = -EFAULT;
	}

	done:
	mutex_unlock(&hci_smd_enable);
	return ret;
	}


	MODULE_AUTHOR("Ankur Nandwani <ankurn@codeaurora.org>");
	MODULE_DESCRIPTION("Bluetooth SMD driver");
	MODULE_LICENSE("GPL v2");