/*
   *
   *  Bluetooth HCI UART driver for Intel devices
   *
   *  Copyright (C) 2015  Intel Corporation
   *
   *
   *  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.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/skbuff.h>

  #include <linux/firmware.h>

  #include <linux/module.h>

  #include <linux/wait.h>

  #include <linux/tty.h>
  #include <linux/platform_device.h>
  #include <linux/gpio/consumer.h>
  #include <linux/acpi.h>

  #include <linux/interrupt.h>

  #include <linux/pm_runtime.h>

  
  #include <net/bluetooth/bluetooth.h>
  #include <net/bluetooth/hci_core.h>
  
  #include "hci_uart.h"

  #include "btintel.h"
  
  #define STATE_BOOTLOADER	0
  #define STATE_DOWNLOADING	1
  #define STATE_FIRMWARE_LOADED	2
  #define STATE_FIRMWARE_FAILED	3
  #define STATE_BOOTING		4

  #define STATE_LPM_ENABLED	5
  #define STATE_TX_ACTIVE		6

  #define STATE_SUSPENDED		7
  #define STATE_LPM_TRANSACTION	8

  #define HCI_LPM_WAKE_PKT 0xf0

  #define HCI_LPM_PKT 0xf1
  #define HCI_LPM_MAX_SIZE 10
  #define HCI_LPM_HDR_SIZE HCI_EVENT_HDR_SIZE
  
  #define LPM_OP_TX_NOTIFY 0x00

  #define LPM_OP_SUSPEND_ACK 0x02
  #define LPM_OP_RESUME_ACK 0x03

  #define LPM_SUSPEND_DELAY_MS 1000

  struct hci_lpm_pkt {
  	__u8 opcode;
  	__u8 dlen;
  	__u8 data[0];
  } __packed;

  struct intel_device {
  	struct list_head list;
  	struct platform_device *pdev;
  	struct gpio_desc *reset;

  	struct hci_uart *hu;
  	struct mutex hu_lock;

  	int irq;

  };
  
  static LIST_HEAD(intel_device_list);

  static DEFINE_MUTEX(intel_device_list_lock);

  struct intel_data {
  	struct sk_buff *rx_skb;
  	struct sk_buff_head txq;

  	struct work_struct busy_work;
  	struct hci_uart *hu;

  	unsigned long flags;
  };

  static u8 intel_convert_speed(unsigned int speed)
  {
  	switch (speed) {
  	case 9600:
  		return 0x00;
  	case 19200:
  		return 0x01;
  	case 38400:
  		return 0x02;
  	case 57600:
  		return 0x03;
  	case 115200:
  		return 0x04;
  	case 230400:
  		return 0x05;
  	case 460800:
  		return 0x06;
  	case 921600:
  		return 0x07;
  	case 1843200:
  		return 0x08;
  	case 3250000:
  		return 0x09;
  	case 2000000:
  		return 0x0a;
  	case 3000000:
  		return 0x0b;
  	default:
  		return 0xff;
  	}
  }

  static int intel_wait_booting(struct hci_uart *hu)
  {
  	struct intel_data *intel = hu->priv;
  	int err;
  
  	err = wait_on_bit_timeout(&intel->flags, STATE_BOOTING,
  				  TASK_INTERRUPTIBLE,
  				  msecs_to_jiffies(1000));

  	if (err == -EINTR) {

  		bt_dev_err(hu->hdev, "Device boot interrupted");

  		return -EINTR;
  	}
  
  	if (err) {

  		bt_dev_err(hu->hdev, "Device boot timeout");

  		return -ETIMEDOUT;
  	}
  
  	return err;
  }

  #ifdef CONFIG_PM

  static int intel_wait_lpm_transaction(struct hci_uart *hu)
  {
  	struct intel_data *intel = hu->priv;
  	int err;
  
  	err = wait_on_bit_timeout(&intel->flags, STATE_LPM_TRANSACTION,
  				  TASK_INTERRUPTIBLE,
  				  msecs_to_jiffies(1000));

  	if (err == -EINTR) {

  		bt_dev_err(hu->hdev, "LPM transaction interrupted");
  		return -EINTR;
  	}
  
  	if (err) {
  		bt_dev_err(hu->hdev, "LPM transaction timeout");
  		return -ETIMEDOUT;
  	}
  
  	return err;
  }
  
  static int intel_lpm_suspend(struct hci_uart *hu)
  {
  	static const u8 suspend[] = { 0x01, 0x01, 0x01 };
  	struct intel_data *intel = hu->priv;
  	struct sk_buff *skb;
  
  	if (!test_bit(STATE_LPM_ENABLED, &intel->flags) ||
  	    test_bit(STATE_SUSPENDED, &intel->flags))
  		return 0;
  
  	if (test_bit(STATE_TX_ACTIVE, &intel->flags))
  		return -EAGAIN;
  
  	bt_dev_dbg(hu->hdev, "Suspending");
  
  	skb = bt_skb_alloc(sizeof(suspend), GFP_KERNEL);
  	if (!skb) {
  		bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
  		return -ENOMEM;
  	}
  
  	memcpy(skb_put(skb, sizeof(suspend)), suspend, sizeof(suspend));

  	hci_skb_pkt_type(skb) = HCI_LPM_PKT;

  
  	set_bit(STATE_LPM_TRANSACTION, &intel->flags);

  	/* LPM flow is a priority, enqueue packet at list head */
  	skb_queue_head(&intel->txq, skb);

  	hci_uart_tx_wakeup(hu);
  
  	intel_wait_lpm_transaction(hu);
  	/* Even in case of failure, continue and test the suspended flag */
  
  	clear_bit(STATE_LPM_TRANSACTION, &intel->flags);
  
  	if (!test_bit(STATE_SUSPENDED, &intel->flags)) {
  		bt_dev_err(hu->hdev, "Device suspend error");
  		return -EINVAL;
  	}
  
  	bt_dev_dbg(hu->hdev, "Suspended");
  
  	hci_uart_set_flow_control(hu, true);
  
  	return 0;
  }
  
  static int intel_lpm_resume(struct hci_uart *hu)
  {
  	struct intel_data *intel = hu->priv;
  	struct sk_buff *skb;
  
  	if (!test_bit(STATE_LPM_ENABLED, &intel->flags) ||
  	    !test_bit(STATE_SUSPENDED, &intel->flags))
  		return 0;
  
  	bt_dev_dbg(hu->hdev, "Resuming");
  
  	hci_uart_set_flow_control(hu, false);
  
  	skb = bt_skb_alloc(0, GFP_KERNEL);
  	if (!skb) {
  		bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
  		return -ENOMEM;
  	}

  	hci_skb_pkt_type(skb) = HCI_LPM_WAKE_PKT;

  
  	set_bit(STATE_LPM_TRANSACTION, &intel->flags);

  	/* LPM flow is a priority, enqueue packet at list head */
  	skb_queue_head(&intel->txq, skb);

  	hci_uart_tx_wakeup(hu);
  
  	intel_wait_lpm_transaction(hu);
  	/* Even in case of failure, continue and test the suspended flag */
  
  	clear_bit(STATE_LPM_TRANSACTION, &intel->flags);
  
  	if (test_bit(STATE_SUSPENDED, &intel->flags)) {
  		bt_dev_err(hu->hdev, "Device resume error");
  		return -EINVAL;
  	}
  
  	bt_dev_dbg(hu->hdev, "Resumed");
  
  	return 0;
  }

  #endif /* CONFIG_PM */

  
  static int intel_lpm_host_wake(struct hci_uart *hu)
  {
  	static const u8 lpm_resume_ack[] = { LPM_OP_RESUME_ACK, 0x00 };
  	struct intel_data *intel = hu->priv;
  	struct sk_buff *skb;
  
  	hci_uart_set_flow_control(hu, false);
  
  	clear_bit(STATE_SUSPENDED, &intel->flags);
  
  	skb = bt_skb_alloc(sizeof(lpm_resume_ack), GFP_KERNEL);
  	if (!skb) {
  		bt_dev_err(hu->hdev, "Failed to alloc memory for LPM packet");
  		return -ENOMEM;
  	}
  
  	memcpy(skb_put(skb, sizeof(lpm_resume_ack)), lpm_resume_ack,
  	       sizeof(lpm_resume_ack));

  	hci_skb_pkt_type(skb) = HCI_LPM_PKT;

  	/* LPM flow is a priority, enqueue packet at list head */
  	skb_queue_head(&intel->txq, skb);

  	hci_uart_tx_wakeup(hu);
  
  	bt_dev_dbg(hu->hdev, "Resumed by controller");
  
  	return 0;
  }

  static irqreturn_t intel_irq(int irq, void *dev_id)
  {
  	struct intel_device *idev = dev_id;
  
  	dev_info(&idev->pdev->dev, "hci_intel irq
  ");

  	mutex_lock(&idev->hu_lock);
  	if (idev->hu)
  		intel_lpm_host_wake(idev->hu);
  	mutex_unlock(&idev->hu_lock);

  	/* Host/Controller are now LPM resumed, trigger a new delayed suspend */
  	pm_runtime_get(&idev->pdev->dev);
  	pm_runtime_mark_last_busy(&idev->pdev->dev);
  	pm_runtime_put_autosuspend(&idev->pdev->dev);

  	return IRQ_HANDLED;
  }

  static int intel_set_power(struct hci_uart *hu, bool powered)
  {
  	struct list_head *p;
  	int err = -ENODEV;

  	mutex_lock(&intel_device_list_lock);

  
  	list_for_each(p, &intel_device_list) {
  		struct intel_device *idev = list_entry(p, struct intel_device,
  						       list);
  
  		/* tty device and pdev device should share the same parent
  		 * which is the UART port.
  		 */
  		if (hu->tty->dev->parent != idev->pdev->dev.parent)
  			continue;
  
  		if (!idev->reset) {
  			err = -ENOTSUPP;
  			break;
  		}
  
  		BT_INFO("hu %p, Switching compatible pm device (%s) to %u",
  			hu, dev_name(&idev->pdev->dev), powered);
  
  		gpiod_set_value(idev->reset, powered);

  		/* Provide to idev a hu reference which is used to run LPM
  		 * transactions (lpm suspend/resume) from PM callbacks.
  		 * hu needs to be protected against concurrent removing during
  		 * these PM ops.
  		 */
  		mutex_lock(&idev->hu_lock);
  		idev->hu = powered ? hu : NULL;
  		mutex_unlock(&idev->hu_lock);

  		if (idev->irq < 0)
  			break;
  
  		if (powered && device_can_wakeup(&idev->pdev->dev)) {
  			err = devm_request_threaded_irq(&idev->pdev->dev,
  							idev->irq, NULL,
  							intel_irq,
  							IRQF_ONESHOT,
  							"bt-host-wake", idev);
  			if (err) {
  				BT_ERR("hu %p, unable to allocate irq-%d",
  				       hu, idev->irq);
  				break;
  			}
  
  			device_wakeup_enable(&idev->pdev->dev);

  
  			pm_runtime_set_active(&idev->pdev->dev);
  			pm_runtime_use_autosuspend(&idev->pdev->dev);
  			pm_runtime_set_autosuspend_delay(&idev->pdev->dev,
  							 LPM_SUSPEND_DELAY_MS);
  			pm_runtime_enable(&idev->pdev->dev);

  		} else if (!powered && device_may_wakeup(&idev->pdev->dev)) {
  			devm_free_irq(&idev->pdev->dev, idev->irq, idev);
  			device_wakeup_disable(&idev->pdev->dev);

  
  			pm_runtime_disable(&idev->pdev->dev);

  		}

  	}

  	mutex_unlock(&intel_device_list_lock);

  
  	return err;
  }

  static void intel_busy_work(struct work_struct *work)
  {
  	struct list_head *p;
  	struct intel_data *intel = container_of(work, struct intel_data,
  						busy_work);
  
  	/* Link is busy, delay the suspend */
  	mutex_lock(&intel_device_list_lock);
  	list_for_each(p, &intel_device_list) {
  		struct intel_device *idev = list_entry(p, struct intel_device,
  						       list);
  
  		if (intel->hu->tty->dev->parent == idev->pdev->dev.parent) {
  			pm_runtime_get(&idev->pdev->dev);
  			pm_runtime_mark_last_busy(&idev->pdev->dev);
  			pm_runtime_put_autosuspend(&idev->pdev->dev);
  			break;
  		}
  	}
  	mutex_unlock(&intel_device_list_lock);
  }

  static int intel_open(struct hci_uart *hu)
  {
  	struct intel_data *intel;
  
  	BT_DBG("hu %p", hu);
  
  	intel = kzalloc(sizeof(*intel), GFP_KERNEL);
  	if (!intel)
  		return -ENOMEM;
  
  	skb_queue_head_init(&intel->txq);

  	INIT_WORK(&intel->busy_work, intel_busy_work);
  
  	intel->hu = hu;

  
  	hu->priv = intel;

  
  	if (!intel_set_power(hu, true))
  		set_bit(STATE_BOOTING, &intel->flags);

  	return 0;
  }
  
  static int intel_close(struct hci_uart *hu)
  {
  	struct intel_data *intel = hu->priv;
  
  	BT_DBG("hu %p", hu);

  	cancel_work_sync(&intel->busy_work);

  	intel_set_power(hu, false);

  	skb_queue_purge(&intel->txq);
  	kfree_skb(intel->rx_skb);
  	kfree(intel);
  
  	hu->priv = NULL;
  	return 0;
  }
  
  static int intel_flush(struct hci_uart *hu)
  {
  	struct intel_data *intel = hu->priv;
  
  	BT_DBG("hu %p", hu);
  
  	skb_queue_purge(&intel->txq);
  
  	return 0;
  }
  
  static int inject_cmd_complete(struct hci_dev *hdev, __u16 opcode)
  {
  	struct sk_buff *skb;
  	struct hci_event_hdr *hdr;
  	struct hci_ev_cmd_complete *evt;
  
  	skb = bt_skb_alloc(sizeof(*hdr) + sizeof(*evt) + 1, GFP_ATOMIC);
  	if (!skb)
  		return -ENOMEM;
  
  	hdr = (struct hci_event_hdr *)skb_put(skb, sizeof(*hdr));
  	hdr->evt = HCI_EV_CMD_COMPLETE;
  	hdr->plen = sizeof(*evt) + 1;
  
  	evt = (struct hci_ev_cmd_complete *)skb_put(skb, sizeof(*evt));
  	evt->ncmd = 0x01;
  	evt->opcode = cpu_to_le16(opcode);
  
  	*skb_put(skb, 1) = 0x00;

  	hci_skb_pkt_type(skb) = HCI_EVENT_PKT;

  
  	return hci_recv_frame(hdev, skb);
  }

  static int intel_set_baudrate(struct hci_uart *hu, unsigned int speed)
  {
  	struct intel_data *intel = hu->priv;
  	struct hci_dev *hdev = hu->hdev;
  	u8 speed_cmd[] = { 0x06, 0xfc, 0x01, 0x00 };
  	struct sk_buff *skb;

  	int err;
  
  	/* This can be the first command sent to the chip, check
  	 * that the controller is ready.
  	 */
  	err = intel_wait_booting(hu);
  
  	clear_bit(STATE_BOOTING, &intel->flags);
  
  	/* In case of timeout, try to continue anyway */

  	if (err && err != -ETIMEDOUT)

  		return err;

  	bt_dev_info(hdev, "Change controller speed to %d", speed);

  
  	speed_cmd[3] = intel_convert_speed(speed);
  	if (speed_cmd[3] == 0xff) {

  		bt_dev_err(hdev, "Unsupported speed");

  		return -EINVAL;
  	}
  
  	/* Device will not accept speed change if Intel version has not been
  	 * previously requested.
  	 */

  	skb = __hci_cmd_sync(hdev, 0xfc05, 0, NULL, HCI_CMD_TIMEOUT);

  	if (IS_ERR(skb)) {

  		bt_dev_err(hdev, "Reading Intel version information failed (%ld)",
  			   PTR_ERR(skb));

  		return PTR_ERR(skb);
  	}
  	kfree_skb(skb);
  
  	skb = bt_skb_alloc(sizeof(speed_cmd), GFP_KERNEL);
  	if (!skb) {

  		bt_dev_err(hdev, "Failed to alloc memory for baudrate packet");

  		return -ENOMEM;
  	}
  
  	memcpy(skb_put(skb, sizeof(speed_cmd)), speed_cmd, sizeof(speed_cmd));

  	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;

  
  	hci_uart_set_flow_control(hu, true);
  
  	skb_queue_tail(&intel->txq, skb);
  	hci_uart_tx_wakeup(hu);
  
  	/* wait 100ms to change baudrate on controller side */
  	msleep(100);
  
  	hci_uart_set_baudrate(hu, speed);
  	hci_uart_set_flow_control(hu, false);
  
  	return 0;
  }

  static int intel_setup(struct hci_uart *hu)
  {
  	static const u8 reset_param[] = { 0x00, 0x01, 0x00, 0x01,
  					  0x00, 0x08, 0x04, 0x00 };
  	struct intel_data *intel = hu->priv;
  	struct hci_dev *hdev = hu->hdev;
  	struct sk_buff *skb;

  	struct intel_version ver;

  	struct intel_boot_params *params;

  	struct list_head *p;

  	const struct firmware *fw;
  	const u8 *fw_ptr;
  	char fwname[64];
  	u32 frag_len;
  	ktime_t calltime, delta, rettime;
  	unsigned long long duration;

  	unsigned int init_speed, oper_speed;
  	int speed_change = 0;

  	int err;

  	bt_dev_dbg(hdev, "start intel_setup");

  	hu->hdev->set_diag = btintel_set_diag;

  	hu->hdev->set_bdaddr = btintel_set_bdaddr;

  	calltime = ktime_get();

  	if (hu->init_speed)
  		init_speed = hu->init_speed;
  	else
  		init_speed = hu->proto->init_speed;
  
  	if (hu->oper_speed)
  		oper_speed = hu->oper_speed;
  	else
  		oper_speed = hu->proto->oper_speed;
  
  	if (oper_speed && init_speed && oper_speed != init_speed)
  		speed_change = 1;

  	/* Check that the controller is ready */
  	err = intel_wait_booting(hu);
  
  	clear_bit(STATE_BOOTING, &intel->flags);
  
  	/* In case of timeout, try to continue anyway */

  	if (err && err != -ETIMEDOUT)

  		return err;

  	set_bit(STATE_BOOTLOADER, &intel->flags);
  
  	/* Read the Intel version information to determine if the device
  	 * is in bootloader mode or if it already has operational firmware
  	 * loaded.
  	 */

  	 err = btintel_read_version(hdev, &ver);
  	 if (err)

  		return err;

  
  	/* The hardware platform number has a fixed value of 0x37 and
  	 * for now only accept this single value.
  	 */

  	if (ver.hw_platform != 0x37) {

  		bt_dev_err(hdev, "Unsupported Intel hardware platform (%u)",

  			   ver.hw_platform);

  		return -EINVAL;
  	}
  
  	/* At the moment only the hardware variant iBT 3.0 (LnP/SfP) is
  	 * supported by this firmware loading method. This check has been
  	 * put in place to ensure correct forward compatibility options
  	 * when newer hardware variants come along.
  	 */

  	if (ver.hw_variant != 0x0b) {

  		bt_dev_err(hdev, "Unsupported Intel hardware variant (%u)",

  			   ver.hw_variant);

  		return -EINVAL;
  	}

  	btintel_version_info(hdev, &ver);

  
  	/* The firmware variant determines if the device is in bootloader
  	 * mode or is running operational firmware. The value 0x06 identifies
  	 * the bootloader and the value 0x23 identifies the operational
  	 * firmware.
  	 *
  	 * When the operational firmware is already present, then only
  	 * the check for valid Bluetooth device address is needed. This
  	 * determines if the device will be added as configured or
  	 * unconfigured controller.
  	 *
  	 * It is not possible to use the Secure Boot Parameters in this
  	 * case since that command is only available in bootloader mode.
  	 */

  	if (ver.fw_variant == 0x23) {

  		clear_bit(STATE_BOOTLOADER, &intel->flags);
  		btintel_check_bdaddr(hdev);
  		return 0;
  	}
  
  	/* If the device is not in bootloader mode, then the only possible
  	 * choice is to return an error and abort the device initialization.
  	 */

  	if (ver.fw_variant != 0x06) {

  		bt_dev_err(hdev, "Unsupported Intel firmware variant (%u)",

  			   ver.fw_variant);

  		return -ENODEV;
  	}

  	/* Read the secure boot parameters to identify the operating
  	 * details of the bootloader.
  	 */

  	skb = __hci_cmd_sync(hdev, 0xfc0d, 0, NULL, HCI_CMD_TIMEOUT);

  	if (IS_ERR(skb)) {

  		bt_dev_err(hdev, "Reading Intel boot parameters failed (%ld)",
  			   PTR_ERR(skb));

  		return PTR_ERR(skb);
  	}
  
  	if (skb->len != sizeof(*params)) {

  		bt_dev_err(hdev, "Intel boot parameters size mismatch");

  		kfree_skb(skb);
  		return -EILSEQ;
  	}
  
  	params = (struct intel_boot_params *)skb->data;
  	if (params->status) {

  		bt_dev_err(hdev, "Intel boot parameters command failure (%02x)",
  			   params->status);

  		err = -bt_to_errno(params->status);
  		kfree_skb(skb);
  		return err;
  	}

  	bt_dev_info(hdev, "Device revision is %u",
  		    le16_to_cpu(params->dev_revid));

  	bt_dev_info(hdev, "Secure boot is %s",
  		    params->secure_boot ? "enabled" : "disabled");

  	bt_dev_info(hdev, "Minimum firmware build %u week %u %u",

  		params->min_fw_build_nn, params->min_fw_build_cw,
  		2000 + params->min_fw_build_yy);
  
  	/* It is required that every single firmware fragment is acknowledged
  	 * with a command complete event. If the boot parameters indicate
  	 * that this bootloader does not send them, then abort the setup.
  	 */
  	if (params->limited_cce != 0x00) {

  		bt_dev_err(hdev, "Unsupported Intel firmware loading method (%u)",
  			   params->limited_cce);

  		kfree_skb(skb);
  		return -EINVAL;
  	}
  
  	/* If the OTP has no valid Bluetooth device address, then there will
  	 * also be no valid address for the operational firmware.
  	 */
  	if (!bacmp(&params->otp_bdaddr, BDADDR_ANY)) {

  		bt_dev_info(hdev, "No device address configured");

  		set_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks);
  	}
  
  	/* With this Intel bootloader only the hardware variant and device
  	 * revision information are used to select the right firmware.
  	 *
  	 * Currently this bootloader support is limited to hardware variant
  	 * iBT 3.0 (LnP/SfP) which is identified by the value 11 (0x0b).
  	 */
  	snprintf(fwname, sizeof(fwname), "intel/ibt-11-%u.sfi",
  		 le16_to_cpu(params->dev_revid));
  
  	err = request_firmware(&fw, fwname, &hdev->dev);
  	if (err < 0) {

  		bt_dev_err(hdev, "Failed to load Intel firmware file (%d)",
  			   err);

  		kfree_skb(skb);
  		return err;
  	}

  	bt_dev_info(hdev, "Found device firmware: %s", fwname);

  	/* Save the DDC file name for later */
  	snprintf(fwname, sizeof(fwname), "intel/ibt-11-%u.ddc",
  		 le16_to_cpu(params->dev_revid));

  	kfree_skb(skb);
  
  	if (fw->size < 644) {

  		bt_dev_err(hdev, "Invalid size of firmware file (%zu)",
  			   fw->size);

  		err = -EBADF;
  		goto done;
  	}
  
  	set_bit(STATE_DOWNLOADING, &intel->flags);
  
  	/* Start the firmware download transaction with the Init fragment
  	 * represented by the 128 bytes of CSS header.
  	 */

  	err = btintel_secure_send(hdev, 0x00, 128, fw->data);

  	if (err < 0) {

  		bt_dev_err(hdev, "Failed to send firmware header (%d)", err);

  		goto done;
  	}
  
  	/* Send the 256 bytes of public key information from the firmware
  	 * as the PKey fragment.
  	 */

  	err = btintel_secure_send(hdev, 0x03, 256, fw->data + 128);

  	if (err < 0) {

  		bt_dev_err(hdev, "Failed to send firmware public key (%d)",
  			   err);

  		goto done;
  	}
  
  	/* Send the 256 bytes of signature information from the firmware
  	 * as the Sign fragment.
  	 */

  	err = btintel_secure_send(hdev, 0x02, 256, fw->data + 388);

  	if (err < 0) {

  		bt_dev_err(hdev, "Failed to send firmware signature (%d)",
  			   err);

  		goto done;
  	}
  
  	fw_ptr = fw->data + 644;
  	frag_len = 0;
  
  	while (fw_ptr - fw->data < fw->size) {
  		struct hci_command_hdr *cmd = (void *)(fw_ptr + frag_len);
  
  		frag_len += sizeof(*cmd) + cmd->plen;

  		bt_dev_dbg(hdev, "Patching %td/%zu", (fw_ptr - fw->data),
  			   fw->size);

  
  		/* The parameter length of the secure send command requires
  		 * a 4 byte alignment. It happens so that the firmware file
  		 * contains proper Intel_NOP commands to align the fragments
  		 * as needed.
  		 *
  		 * Send set of commands with 4 byte alignment from the
  		 * firmware data buffer as a single Data fragement.
  		 */
  		if (frag_len % 4)
  			continue;
  
  		/* Send each command from the firmware data buffer as
  		 * a single Data fragment.
  		 */

  		err = btintel_secure_send(hdev, 0x01, frag_len, fw_ptr);

  		if (err < 0) {

  			bt_dev_err(hdev, "Failed to send firmware data (%d)",
  				   err);

  			goto done;
  		}
  
  		fw_ptr += frag_len;
  		frag_len = 0;
  	}
  
  	set_bit(STATE_FIRMWARE_LOADED, &intel->flags);

  	bt_dev_info(hdev, "Waiting for firmware download to complete");

  
  	/* Before switching the device into operational mode and with that
  	 * booting the loaded firmware, wait for the bootloader notification
  	 * that all fragments have been successfully received.
  	 *
  	 * When the event processing receives the notification, then the
  	 * STATE_DOWNLOADING flag will be cleared.
  	 *
  	 * The firmware loading should not take longer than 5 seconds
  	 * and thus just timeout if that happens and fail the setup
  	 * of this device.
  	 */
  	err = wait_on_bit_timeout(&intel->flags, STATE_DOWNLOADING,
  				  TASK_INTERRUPTIBLE,
  				  msecs_to_jiffies(5000));

  	if (err == -EINTR) {

  		bt_dev_err(hdev, "Firmware loading interrupted");

  		err = -EINTR;
  		goto done;
  	}
  
  	if (err) {

  		bt_dev_err(hdev, "Firmware loading timeout");

  		err = -ETIMEDOUT;
  		goto done;
  	}
  
  	if (test_bit(STATE_FIRMWARE_FAILED, &intel->flags)) {

  		bt_dev_err(hdev, "Firmware loading failed");

  		err = -ENOEXEC;
  		goto done;
  	}
  
  	rettime = ktime_get();
  	delta = ktime_sub(rettime, calltime);
  	duration = (unsigned long long) ktime_to_ns(delta) >> 10;

  	bt_dev_info(hdev, "Firmware loaded in %llu usecs", duration);

  
  done:
  	release_firmware(fw);
  
  	if (err < 0)
  		return err;

  	/* We need to restore the default speed before Intel reset */
  	if (speed_change) {
  		err = intel_set_baudrate(hu, init_speed);
  		if (err)
  			return err;
  	}

  	calltime = ktime_get();
  
  	set_bit(STATE_BOOTING, &intel->flags);
  
  	skb = __hci_cmd_sync(hdev, 0xfc01, sizeof(reset_param), reset_param,

  			     HCI_CMD_TIMEOUT);

  	if (IS_ERR(skb))
  		return PTR_ERR(skb);
  
  	kfree_skb(skb);
  
  	/* The bootloader will not indicate when the device is ready. This
  	 * is done by the operational firmware sending bootup notification.
  	 *
  	 * Booting into operational firmware should not take longer than
  	 * 1 second. However if that happens, then just fail the setup
  	 * since something went wrong.
  	 */

  	bt_dev_info(hdev, "Waiting for device to boot");

  	err = intel_wait_booting(hu);
  	if (err)
  		return err;

  	clear_bit(STATE_BOOTING, &intel->flags);

  
  	rettime = ktime_get();
  	delta = ktime_sub(rettime, calltime);
  	duration = (unsigned long long) ktime_to_ns(delta) >> 10;

  	bt_dev_info(hdev, "Device booted in %llu usecs", duration);

  	/* Enable LPM if matching pdev with wakeup enabled, set TX active
  	 * until further LPM TX notification.
  	 */

  	mutex_lock(&intel_device_list_lock);

  	list_for_each(p, &intel_device_list) {
  		struct intel_device *dev = list_entry(p, struct intel_device,
  						      list);
  		if (hu->tty->dev->parent == dev->pdev->dev.parent) {

  			if (device_may_wakeup(&dev->pdev->dev)) {
  				set_bit(STATE_LPM_ENABLED, &intel->flags);
  				set_bit(STATE_TX_ACTIVE, &intel->flags);
  			}

  			break;
  		}
  	}

  	mutex_unlock(&intel_device_list_lock);

  	/* Ignore errors, device can work without DDC parameters */
  	btintel_load_ddc_config(hdev, fwname);

  	skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL, HCI_CMD_TIMEOUT);
  	if (IS_ERR(skb))
  		return PTR_ERR(skb);
  	kfree_skb(skb);
  
  	if (speed_change) {
  		err = intel_set_baudrate(hu, oper_speed);
  		if (err)
  			return err;
  	}

  	bt_dev_info(hdev, "Setup complete");

  	clear_bit(STATE_BOOTLOADER, &intel->flags);
  
  	return 0;
  }
  
  static int intel_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
  {
  	struct hci_uart *hu = hci_get_drvdata(hdev);
  	struct intel_data *intel = hu->priv;
  	struct hci_event_hdr *hdr;

  	if (!test_bit(STATE_BOOTLOADER, &intel->flags) &&
  	    !test_bit(STATE_BOOTING, &intel->flags))

  		goto recv;
  
  	hdr = (void *)skb->data;
  
  	/* When the firmware loading completes the device sends
  	 * out a vendor specific event indicating the result of
  	 * the firmware loading.
  	 */
  	if (skb->len == 7 && hdr->evt == 0xff && hdr->plen == 0x05 &&
  	    skb->data[2] == 0x06) {
  		if (skb->data[3] != 0x00)
  			set_bit(STATE_FIRMWARE_FAILED, &intel->flags);
  
  		if (test_and_clear_bit(STATE_DOWNLOADING, &intel->flags) &&
  		    test_bit(STATE_FIRMWARE_LOADED, &intel->flags)) {
  			smp_mb__after_atomic();
  			wake_up_bit(&intel->flags, STATE_DOWNLOADING);
  		}
  
  	/* When switching to the operational firmware the device
  	 * sends a vendor specific event indicating that the bootup
  	 * completed.
  	 */
  	} else if (skb->len == 9 && hdr->evt == 0xff && hdr->plen == 0x07 &&
  		   skb->data[2] == 0x02) {
  		if (test_and_clear_bit(STATE_BOOTING, &intel->flags)) {
  			smp_mb__after_atomic();
  			wake_up_bit(&intel->flags, STATE_BOOTING);
  		}
  	}
  recv:
  	return hci_recv_frame(hdev, skb);
  }

  static void intel_recv_lpm_notify(struct hci_dev *hdev, int value)
  {
  	struct hci_uart *hu = hci_get_drvdata(hdev);
  	struct intel_data *intel = hu->priv;

  	bt_dev_dbg(hdev, "TX idle notification (%d)", value);

  	if (value) {

  		set_bit(STATE_TX_ACTIVE, &intel->flags);

  		schedule_work(&intel->busy_work);
  	} else {

  		clear_bit(STATE_TX_ACTIVE, &intel->flags);

  	}

  }
  
  static int intel_recv_lpm(struct hci_dev *hdev, struct sk_buff *skb)
  {
  	struct hci_lpm_pkt *lpm = (void *)skb->data;

  	struct hci_uart *hu = hci_get_drvdata(hdev);
  	struct intel_data *intel = hu->priv;

  
  	switch (lpm->opcode) {
  	case LPM_OP_TX_NOTIFY:

  		if (lpm->dlen < 1) {
  			bt_dev_err(hu->hdev, "Invalid LPM notification packet");
  			break;
  		}
  		intel_recv_lpm_notify(hdev, lpm->data[0]);

  		break;

  	case LPM_OP_SUSPEND_ACK:
  		set_bit(STATE_SUSPENDED, &intel->flags);
  		if (test_and_clear_bit(STATE_LPM_TRANSACTION, &intel->flags)) {
  			smp_mb__after_atomic();
  			wake_up_bit(&intel->flags, STATE_LPM_TRANSACTION);
  		}
  		break;
  	case LPM_OP_RESUME_ACK:
  		clear_bit(STATE_SUSPENDED, &intel->flags);
  		if (test_and_clear_bit(STATE_LPM_TRANSACTION, &intel->flags)) {
  			smp_mb__after_atomic();
  			wake_up_bit(&intel->flags, STATE_LPM_TRANSACTION);
  		}
  		break;

  	default:

  		bt_dev_err(hdev, "Unknown LPM opcode (%02x)", lpm->opcode);

  		break;
  	}
  
  	kfree_skb(skb);
  
  	return 0;
  }
  
  #define INTEL_RECV_LPM \
  	.type = HCI_LPM_PKT, \
  	.hlen = HCI_LPM_HDR_SIZE, \
  	.loff = 1, \
  	.lsize = 1, \
  	.maxlen = HCI_LPM_MAX_SIZE

  static const struct h4_recv_pkt intel_recv_pkts[] = {

  	{ H4_RECV_ACL,    .recv = hci_recv_frame   },
  	{ H4_RECV_SCO,    .recv = hci_recv_frame   },
  	{ H4_RECV_EVENT,  .recv = intel_recv_event },
  	{ INTEL_RECV_LPM, .recv = intel_recv_lpm   },

  };
  
  static int intel_recv(struct hci_uart *hu, const void *data, int count)
  {
  	struct intel_data *intel = hu->priv;
  
  	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
  		return -EUNATCH;
  
  	intel->rx_skb = h4_recv_buf(hu->hdev, intel->rx_skb, data, count,
  				    intel_recv_pkts,
  				    ARRAY_SIZE(intel_recv_pkts));
  	if (IS_ERR(intel->rx_skb)) {
  		int err = PTR_ERR(intel->rx_skb);

  		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);

  		intel->rx_skb = NULL;
  		return err;
  	}
  
  	return count;
  }
  
  static int intel_enqueue(struct hci_uart *hu, struct sk_buff *skb)
  {
  	struct intel_data *intel = hu->priv;

  	struct list_head *p;

  
  	BT_DBG("hu %p skb %p", hu, skb);

  	/* Be sure our controller is resumed and potential LPM transaction
  	 * completed before enqueuing any packet.
  	 */
  	mutex_lock(&intel_device_list_lock);
  	list_for_each(p, &intel_device_list) {
  		struct intel_device *idev = list_entry(p, struct intel_device,
  						       list);
  
  		if (hu->tty->dev->parent == idev->pdev->dev.parent) {
  			pm_runtime_get_sync(&idev->pdev->dev);
  			pm_runtime_mark_last_busy(&idev->pdev->dev);
  			pm_runtime_put_autosuspend(&idev->pdev->dev);
  			break;
  		}
  	}
  	mutex_unlock(&intel_device_list_lock);

  	skb_queue_tail(&intel->txq, skb);
  
  	return 0;
  }
  
  static struct sk_buff *intel_dequeue(struct hci_uart *hu)
  {
  	struct intel_data *intel = hu->priv;
  	struct sk_buff *skb;
  
  	skb = skb_dequeue(&intel->txq);
  	if (!skb)
  		return skb;
  
  	if (test_bit(STATE_BOOTLOADER, &intel->flags) &&

  	    (hci_skb_pkt_type(skb) == HCI_COMMAND_PKT)) {

  		struct hci_command_hdr *cmd = (void *)skb->data;
  		__u16 opcode = le16_to_cpu(cmd->opcode);
  
  		/* When the 0xfc01 command is issued to boot into
  		 * the operational firmware, it will actually not
  		 * send a command complete event. To keep the flow
  		 * control working inject that event here.
  		 */
  		if (opcode == 0xfc01)
  			inject_cmd_complete(hu->hdev, opcode);
  	}
  
  	/* Prepend skb with frame type */

  	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);

  
  	return skb;
  }
  
  static const struct hci_uart_proto intel_proto = {
  	.id		= HCI_UART_INTEL,
  	.name		= "Intel",

  	.manufacturer	= 2,

  	.init_speed	= 115200,

  	.oper_speed	= 3000000,

  	.open		= intel_open,
  	.close		= intel_close,
  	.flush		= intel_flush,
  	.setup		= intel_setup,

  	.set_baudrate	= intel_set_baudrate,

  	.recv		= intel_recv,
  	.enqueue	= intel_enqueue,
  	.dequeue	= intel_dequeue,
  };

  #ifdef CONFIG_ACPI
  static const struct acpi_device_id intel_acpi_match[] = {
  	{ "INT33E1", 0 },
  	{ },
  };
  MODULE_DEVICE_TABLE(acpi, intel_acpi_match);

  #endif

  #ifdef CONFIG_PM

  static int intel_suspend_device(struct device *dev)

  {
  	struct intel_device *idev = dev_get_drvdata(dev);

  	mutex_lock(&idev->hu_lock);
  	if (idev->hu)
  		intel_lpm_suspend(idev->hu);
  	mutex_unlock(&idev->hu_lock);
  
  	return 0;
  }

  static int intel_resume_device(struct device *dev)

  {
  	struct intel_device *idev = dev_get_drvdata(dev);

  	mutex_lock(&idev->hu_lock);
  	if (idev->hu)
  		intel_lpm_resume(idev->hu);
  	mutex_unlock(&idev->hu_lock);
  
  	return 0;
  }
  #endif

  #ifdef CONFIG_PM_SLEEP
  static int intel_suspend(struct device *dev)
  {
  	struct intel_device *idev = dev_get_drvdata(dev);
  
  	if (device_may_wakeup(dev))
  		enable_irq_wake(idev->irq);
  
  	return intel_suspend_device(dev);
  }
  
  static int intel_resume(struct device *dev)
  {
  	struct intel_device *idev = dev_get_drvdata(dev);
  
  	if (device_may_wakeup(dev))
  		disable_irq_wake(idev->irq);
  
  	return intel_resume_device(dev);
  }
  #endif

  static const struct dev_pm_ops intel_pm_ops = {
  	SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)

  	SET_RUNTIME_PM_OPS(intel_suspend_device, intel_resume_device, NULL)

  };

  static int intel_probe(struct platform_device *pdev)
  {
  	struct intel_device *idev;
  
  	idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
  	if (!idev)
  		return -ENOMEM;

  	mutex_init(&idev->hu_lock);

  	idev->pdev = pdev;

  	idev->reset = devm_gpiod_get(&pdev->dev, "reset", GPIOD_OUT_LOW);

  	if (IS_ERR(idev->reset)) {
  		dev_err(&pdev->dev, "Unable to retrieve gpio
  ");
  		return PTR_ERR(idev->reset);
  	}

  	idev->irq = platform_get_irq(pdev, 0);
  	if (idev->irq < 0) {
  		struct gpio_desc *host_wake;
  
  		dev_err(&pdev->dev, "No IRQ, falling back to gpio-irq
  ");

  		host_wake = devm_gpiod_get(&pdev->dev, "host-wake", GPIOD_IN);

  		if (IS_ERR(host_wake)) {
  			dev_err(&pdev->dev, "Unable to retrieve IRQ
  ");
  			goto no_irq;
  		}
  
  		idev->irq = gpiod_to_irq(host_wake);
  		if (idev->irq < 0) {
  			dev_err(&pdev->dev, "No corresponding irq for gpio
  ");
  			goto no_irq;
  		}
  	}
  
  	/* Only enable wake-up/irq when controller is powered */
  	device_set_wakeup_capable(&pdev->dev, true);
  	device_wakeup_disable(&pdev->dev);
  
  no_irq:

  	platform_set_drvdata(pdev, idev);
  
  	/* Place this instance on the device list */

  	mutex_lock(&intel_device_list_lock);

  	list_add_tail(&idev->list, &intel_device_list);

  	mutex_unlock(&intel_device_list_lock);

  	dev_info(&pdev->dev, "registered, gpio(%d)/irq(%d).
  ",
  		 desc_to_gpio(idev->reset), idev->irq);

  
  	return 0;
  }
  
  static int intel_remove(struct platform_device *pdev)
  {
  	struct intel_device *idev = platform_get_drvdata(pdev);

  	device_wakeup_disable(&pdev->dev);

  	mutex_lock(&intel_device_list_lock);

  	list_del(&idev->list);

  	mutex_unlock(&intel_device_list_lock);

  
  	dev_info(&pdev->dev, "unregistered.
  ");
  
  	return 0;
  }
  
  static struct platform_driver intel_driver = {
  	.probe = intel_probe,
  	.remove = intel_remove,
  	.driver = {
  		.name = "hci_intel",
  		.acpi_match_table = ACPI_PTR(intel_acpi_match),

  		.pm = &intel_pm_ops,

  	},
  };

  int __init intel_init(void)
  {

  	platform_driver_register(&intel_driver);

  	return hci_uart_register_proto(&intel_proto);
  }
  
  int __exit intel_deinit(void)
  {

  	platform_driver_unregister(&intel_driver);

  	return hci_uart_unregister_proto(&intel_proto);
  }