/*
 *  Bluetooth Software UART Qualcomm protocol
 *
 *  HCI_IBS (HCI In-Band Sleep) is Qualcomm's power management
 *  protocol extension to H4.
 *
 *  Copyright (C) 2007 Texas Instruments, Inc.
 *  Copyright (c) 2010, 2012 The Linux Foundation. All rights reserved.
 *
 *  Acknowledgements:
 *  This file is based on hci_ll.c, which was...
 *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
 *  which was in turn based on hci_h4.c, which was written
 *  by Maxim Krasnyansky and Marcel Holtmann.
 *
 *  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.
 *
 *  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/debugfs.h>

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

#include "hci_uart.h"
#include "btqca.h"

/* HCI_IBS protocol messages */
#define HCI_IBS_SLEEP_IND       0xFE
#define HCI_IBS_WAKE_IND        0xFD
#define HCI_IBS_WAKE_ACK        0xFC
#define HCI_MAX_IBS_SIZE        10

/* Controller states */
#define STATE_IN_BAND_SLEEP_ENABLED     1

#define IBS_WAKE_RETRANS_TIMEOUT_MS     100
#define IBS_TX_IDLE_TIMEOUT_MS          2000
#define BAUDRATE_SETTLE_TIMEOUT_MS      300

/* HCI_IBS transmit side sleep protocol states */
enum tx_ibs_states {
        HCI_IBS_TX_ASLEEP,
        HCI_IBS_TX_WAKING,
        HCI_IBS_TX_AWAKE,
};

/* HCI_IBS receive side sleep protocol states */
enum rx_states {
        HCI_IBS_RX_ASLEEP,
        HCI_IBS_RX_AWAKE,
};

/* HCI_IBS transmit and receive side clock state vote */
enum hci_ibs_clock_state_vote {
        HCI_IBS_VOTE_STATS_UPDATE,
        HCI_IBS_TX_VOTE_CLOCK_ON,
        HCI_IBS_TX_VOTE_CLOCK_OFF,
        HCI_IBS_RX_VOTE_CLOCK_ON,
        HCI_IBS_RX_VOTE_CLOCK_OFF,
};

struct qca_data {
        struct hci_uart *hu;
        struct sk_buff *rx_skb;
        struct sk_buff_head txq;
        struct sk_buff_head tx_wait_q;  /* HCI_IBS wait queue   */
        spinlock_t hci_ibs_lock;        /* HCI_IBS state lock   */
        u8 tx_ibs_state;        /* HCI_IBS transmit side power state*/
        u8 rx_ibs_state;        /* HCI_IBS receive side power state */
        bool tx_vote;           /* Clock must be on for TX */
        bool rx_vote;           /* Clock must be on for RX */
        struct timer_list tx_idle_timer;
        u32 tx_idle_delay;
        struct timer_list wake_retrans_timer;
        u32 wake_retrans;
        struct workqueue_struct *workqueue;
        struct work_struct ws_awake_rx;
        struct work_struct ws_awake_device;
        struct work_struct ws_rx_vote_off;
        struct work_struct ws_tx_vote_off;
        unsigned long flags;

        /* For debugging purpose */
        u64 ibs_sent_wacks;
        u64 ibs_sent_slps;
        u64 ibs_sent_wakes;
        u64 ibs_recv_wacks;
        u64 ibs_recv_slps;
        u64 ibs_recv_wakes;
        u64 vote_last_jif;
        u32 vote_on_ms;
        u32 vote_off_ms;
        u64 tx_votes_on;
        u64 rx_votes_on;
        u64 tx_votes_off;
        u64 rx_votes_off;
        u64 votes_on;
        u64 votes_off;
};

static void __serial_clock_on(struct tty_struct *tty)
{
        /* TODO: Some chipset requires to enable UART clock on client
         * side to save power consumption or manual work is required.
         * Please put your code to control UART clock here if needed
         */
}

static void __serial_clock_off(struct tty_struct *tty)
{
        /* TODO: Some chipset requires to disable UART clock on client
         * side to save power consumption or manual work is required.
         * Please put your code to control UART clock off here if needed
         */
}

/* serial_clock_vote needs to be called with the ibs lock held */
static void serial_clock_vote(unsigned long vote, struct hci_uart *hu)
{
        struct qca_data *qca = hu->priv;
        unsigned int diff;

        bool old_vote = (qca->tx_vote | qca->rx_vote);
        bool new_vote;

        switch (vote) {
        case HCI_IBS_VOTE_STATS_UPDATE:
                diff = jiffies_to_msecs(jiffies - qca->vote_last_jif);

                if (old_vote)
                        qca->vote_off_ms += diff;
                else
                        qca->vote_on_ms += diff;
                return;

        case HCI_IBS_TX_VOTE_CLOCK_ON:
                qca->tx_vote = true;
                qca->tx_votes_on++;
                new_vote = true;
                break;

        case HCI_IBS_RX_VOTE_CLOCK_ON:
                qca->rx_vote = true;
                qca->rx_votes_on++;
                new_vote = true;
                break;

        case HCI_IBS_TX_VOTE_CLOCK_OFF:
                qca->tx_vote = false;
                qca->tx_votes_off++;
                new_vote = qca->rx_vote | qca->tx_vote;
                break;

        case HCI_IBS_RX_VOTE_CLOCK_OFF:
                qca->rx_vote = false;
                qca->rx_votes_off++;
                new_vote = qca->rx_vote | qca->tx_vote;
                break;

        default:
                BT_ERR("Voting irregularity");
                return;
        }

        if (new_vote != old_vote) {
                if (new_vote)
                        __serial_clock_on(hu->tty);
                else
                        __serial_clock_off(hu->tty);

                BT_DBG("Vote serial clock %s(%s)", new_vote ? "true" : "false",
                       vote ? "true" : "false");

                diff = jiffies_to_msecs(jiffies - qca->vote_last_jif);

                if (new_vote) {
                        qca->votes_on++;
                        qca->vote_off_ms += diff;
                } else {
                        qca->votes_off++;
                        qca->vote_on_ms += diff;
                }
                qca->vote_last_jif = jiffies;
        }
}

/* Builds and sends an HCI_IBS command packet.
 * These are very simple packets with only 1 cmd byte.
 */
static int send_hci_ibs_cmd(u8 cmd, struct hci_uart *hu)
{
        int err = 0;
        struct sk_buff *skb = NULL;
        struct qca_data *qca = hu->priv;

        BT_DBG("hu %p send hci ibs cmd 0x%x", hu, cmd);

        skb = bt_skb_alloc(1, GFP_ATOMIC);
        if (!skb) {
                BT_ERR("Failed to allocate memory for HCI_IBS packet");
                return -ENOMEM;
        }

        /* Assign HCI_IBS type */
        *skb_put(skb, 1) = cmd;

        skb_queue_tail(&qca->txq, skb);

        return err;
}

static void qca_wq_awake_device(struct work_struct *work)
{
        struct qca_data *qca = container_of(work, struct qca_data,
                                            ws_awake_device);
        struct hci_uart *hu = qca->hu;
        unsigned long retrans_delay;

        BT_DBG("hu %p wq awake device", hu);

        /* Vote for serial clock */
        serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_ON, hu);

        spin_lock(&qca->hci_ibs_lock);

        /* Send wake indication to device */
        if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0)
                BT_ERR("Failed to send WAKE to device");

        qca->ibs_sent_wakes++;

        /* Start retransmit timer */
        retrans_delay = msecs_to_jiffies(qca->wake_retrans);
        mod_timer(&qca->wake_retrans_timer, jiffies + retrans_delay);

        spin_unlock(&qca->hci_ibs_lock);

        /* Actually send the packets */
        hci_uart_tx_wakeup(hu);
}

static void qca_wq_awake_rx(struct work_struct *work)
{
        struct qca_data *qca = container_of(work, struct qca_data,
                                            ws_awake_rx);
        struct hci_uart *hu = qca->hu;

        BT_DBG("hu %p wq awake rx", hu);

        serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_ON, hu);

        spin_lock(&qca->hci_ibs_lock);
        qca->rx_ibs_state = HCI_IBS_RX_AWAKE;

        /* Always acknowledge device wake up,
         * sending IBS message doesn't count as TX ON.
         */
        if (send_hci_ibs_cmd(HCI_IBS_WAKE_ACK, hu) < 0)
                BT_ERR("Failed to acknowledge device wake up");

        qca->ibs_sent_wacks++;

        spin_unlock(&qca->hci_ibs_lock);

        /* Actually send the packets */
        hci_uart_tx_wakeup(hu);
}

static void qca_wq_serial_rx_clock_vote_off(struct work_struct *work)
{
        struct qca_data *qca = container_of(work, struct qca_data,
                                            ws_rx_vote_off);
        struct hci_uart *hu = qca->hu;

        BT_DBG("hu %p rx clock vote off", hu);

        serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_OFF, hu);
}

static void qca_wq_serial_tx_clock_vote_off(struct work_struct *work)
{
        struct qca_data *qca = container_of(work, struct qca_data,
                                            ws_tx_vote_off);
        struct hci_uart *hu = qca->hu;

        BT_DBG("hu %p tx clock vote off", hu);

        /* Run HCI tx handling unlocked */
        hci_uart_tx_wakeup(hu);

        /* Now that message queued to tty driver, vote for tty clocks off.
         * It is up to the tty driver to pend the clocks off until tx done.
         */
        serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_OFF, hu);
}

static void hci_ibs_tx_idle_timeout(unsigned long arg)
{
        struct hci_uart *hu = (struct hci_uart *)arg;
        struct qca_data *qca = hu->priv;
        unsigned long flags;

        BT_DBG("hu %p idle timeout in %d state", hu, qca->tx_ibs_state);

        spin_lock_irqsave_nested(&qca->hci_ibs_lock,
                                 flags, SINGLE_DEPTH_NESTING);

        switch (qca->tx_ibs_state) {
        case HCI_IBS_TX_AWAKE:
                /* TX_IDLE, go to SLEEP */
                if (send_hci_ibs_cmd(HCI_IBS_SLEEP_IND, hu) < 0) {
                        BT_ERR("Failed to send SLEEP to device");
                        break;
                }
                qca->tx_ibs_state = HCI_IBS_TX_ASLEEP;
                qca->ibs_sent_slps++;
                queue_work(qca->workqueue, &qca->ws_tx_vote_off);
                break;

        case HCI_IBS_TX_ASLEEP:
        case HCI_IBS_TX_WAKING:
                /* Fall through */

        default:
                BT_ERR("Spurrious timeout tx state %d", qca->tx_ibs_state);
                break;
        }

        spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
}

static void hci_ibs_wake_retrans_timeout(unsigned long arg)
{
        struct hci_uart *hu = (struct hci_uart *)arg;
        struct qca_data *qca = hu->priv;
        unsigned long flags, retrans_delay;
        bool retransmit = false;

        BT_DBG("hu %p wake retransmit timeout in %d state",
                hu, qca->tx_ibs_state);

        spin_lock_irqsave_nested(&qca->hci_ibs_lock,
                                 flags, SINGLE_DEPTH_NESTING);

        switch (qca->tx_ibs_state) {
        case HCI_IBS_TX_WAKING:
                /* No WAKE_ACK, retransmit WAKE */
                retransmit = true;
                if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0) {
                        BT_ERR("Failed to acknowledge device wake up");
                        break;
                }
                qca->ibs_sent_wakes++;
                retrans_delay = msecs_to_jiffies(qca->wake_retrans);
                mod_timer(&qca->wake_retrans_timer, jiffies + retrans_delay);
                break;

        case HCI_IBS_TX_ASLEEP:
        case HCI_IBS_TX_AWAKE:
                /* Fall through */

        default:
                BT_ERR("Spurrious timeout tx state %d", qca->tx_ibs_state);
                break;
        }

        spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);

        if (retransmit)
                hci_uart_tx_wakeup(hu);
}

/* Initialize protocol */
static int qca_open(struct hci_uart *hu)
{
        struct qca_data *qca;

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

        qca = kzalloc(sizeof(struct qca_data), GFP_ATOMIC);
        if (!qca)
                return -ENOMEM;

        skb_queue_head_init(&qca->txq);
        skb_queue_head_init(&qca->tx_wait_q);
        spin_lock_init(&qca->hci_ibs_lock);
        qca->workqueue = alloc_ordered_workqueue("qca_wq", 0);
        if (!qca->workqueue) {
                BT_ERR("QCA Workqueue not initialized properly");
                kfree(qca);
                return -ENOMEM;
        }

        INIT_WORK(&qca->ws_awake_rx, qca_wq_awake_rx);
        INIT_WORK(&qca->ws_awake_device, qca_wq_awake_device);
        INIT_WORK(&qca->ws_rx_vote_off, qca_wq_serial_rx_clock_vote_off);
        INIT_WORK(&qca->ws_tx_vote_off, qca_wq_serial_tx_clock_vote_off);

        qca->hu = hu;

        /* Assume we start with both sides asleep -- extra wakes OK */
        qca->tx_ibs_state = HCI_IBS_TX_ASLEEP;
        qca->rx_ibs_state = HCI_IBS_RX_ASLEEP;

        /* clocks actually on, but we start votes off */
        qca->tx_vote = false;
        qca->rx_vote = false;
        qca->flags = 0;

        qca->ibs_sent_wacks = 0;
        qca->ibs_sent_slps = 0;
        qca->ibs_sent_wakes = 0;
        qca->ibs_recv_wacks = 0;
        qca->ibs_recv_slps = 0;
        qca->ibs_recv_wakes = 0;
        qca->vote_last_jif = jiffies;
        qca->vote_on_ms = 0;
        qca->vote_off_ms = 0;
        qca->votes_on = 0;
        qca->votes_off = 0;
        qca->tx_votes_on = 0;
        qca->tx_votes_off = 0;
        qca->rx_votes_on = 0;
        qca->rx_votes_off = 0;

        hu->priv = qca;

        init_timer(&qca->wake_retrans_timer);
        qca->wake_retrans_timer.function = hci_ibs_wake_retrans_timeout;
        qca->wake_retrans_timer.data = (u_long)hu;
        qca->wake_retrans = IBS_WAKE_RETRANS_TIMEOUT_MS;

        init_timer(&qca->tx_idle_timer);
        qca->tx_idle_timer.function = hci_ibs_tx_idle_timeout;
        qca->tx_idle_timer.data = (u_long)hu;
        qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS;

        BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u, wake_retrans=%u",
               qca->tx_idle_delay, qca->wake_retrans);

        return 0;
}

static void qca_debugfs_init(struct hci_dev *hdev)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);
        struct qca_data *qca = hu->priv;
        struct dentry *ibs_dir;
        umode_t mode;

        if (!hdev->debugfs)
                return;

        ibs_dir = debugfs_create_dir("ibs", hdev->debugfs);

        /* read only */
        mode = S_IRUGO;
        debugfs_create_u8("tx_ibs_state", mode, ibs_dir, &qca->tx_ibs_state);
        debugfs_create_u8("rx_ibs_state", mode, ibs_dir, &qca->rx_ibs_state);
        debugfs_create_u64("ibs_sent_sleeps", mode, ibs_dir,
                           &qca->ibs_sent_slps);
        debugfs_create_u64("ibs_sent_wakes", mode, ibs_dir,
                           &qca->ibs_sent_wakes);
        debugfs_create_u64("ibs_sent_wake_acks", mode, ibs_dir,
                           &qca->ibs_sent_wacks);
        debugfs_create_u64("ibs_recv_sleeps", mode, ibs_dir,
                           &qca->ibs_recv_slps);
        debugfs_create_u64("ibs_recv_wakes", mode, ibs_dir,
                           &qca->ibs_recv_wakes);
        debugfs_create_u64("ibs_recv_wake_acks", mode, ibs_dir,
                           &qca->ibs_recv_wacks);
        debugfs_create_bool("tx_vote", mode, ibs_dir, &qca->tx_vote);
        debugfs_create_u64("tx_votes_on", mode, ibs_dir, &qca->tx_votes_on);
        debugfs_create_u64("tx_votes_off", mode, ibs_dir, &qca->tx_votes_off);
        debugfs_create_bool("rx_vote", mode, ibs_dir, &qca->rx_vote);
        debugfs_create_u64("rx_votes_on", mode, ibs_dir, &qca->rx_votes_on);
        debugfs_create_u64("rx_votes_off", mode, ibs_dir, &qca->rx_votes_off);
        debugfs_create_u64("votes_on", mode, ibs_dir, &qca->votes_on);
        debugfs_create_u64("votes_off", mode, ibs_dir, &qca->votes_off);
        debugfs_create_u32("vote_on_ms", mode, ibs_dir, &qca->vote_on_ms);
        debugfs_create_u32("vote_off_ms", mode, ibs_dir, &qca->vote_off_ms);

        /* read/write */
        mode = S_IRUGO | S_IWUSR;
        debugfs_create_u32("wake_retrans", mode, ibs_dir, &qca->wake_retrans);
        debugfs_create_u32("tx_idle_delay", mode, ibs_dir,
                           &qca->tx_idle_delay);
}

/* Flush protocol data */
static int qca_flush(struct hci_uart *hu)
{
        struct qca_data *qca = hu->priv;

        BT_DBG("hu %p qca flush", hu);

        skb_queue_purge(&qca->tx_wait_q);
        skb_queue_purge(&qca->txq);

        return 0;
}

/* Close protocol */
static int qca_close(struct hci_uart *hu)
{
        struct qca_data *qca = hu->priv;

        BT_DBG("hu %p qca close", hu);

        serial_clock_vote(HCI_IBS_VOTE_STATS_UPDATE, hu);

        skb_queue_purge(&qca->tx_wait_q);
        skb_queue_purge(&qca->txq);
        del_timer(&qca->tx_idle_timer);
        del_timer(&qca->wake_retrans_timer);
        destroy_workqueue(qca->workqueue);
        qca->hu = NULL;

        kfree_skb(qca->rx_skb);

        hu->priv = NULL;

        kfree(qca);

        return 0;
}

/* Called upon a wake-up-indication from the device.
 */
static void device_want_to_wakeup(struct hci_uart *hu)
{
        unsigned long flags;
        struct qca_data *qca = hu->priv;

        BT_DBG("hu %p want to wake up", hu);

        spin_lock_irqsave(&qca->hci_ibs_lock, flags);

        qca->ibs_recv_wakes++;

        switch (qca->rx_ibs_state) {
        case HCI_IBS_RX_ASLEEP:
                /* Make sure clock is on - we may have turned clock off since
                 * receiving the wake up indicator awake rx clock.
                 */
                queue_work(qca->workqueue, &qca->ws_awake_rx);
                spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
                return;

        case HCI_IBS_RX_AWAKE:
                /* Always acknowledge device wake up,
                 * sending IBS message doesn't count as TX ON.
                 */
                if (send_hci_ibs_cmd(HCI_IBS_WAKE_ACK, hu) < 0) {
                        BT_ERR("Failed to acknowledge device wake up");
                        break;
                }
                qca->ibs_sent_wacks++;
                break;

        default:
                /* Any other state is illegal */
                BT_ERR("Received HCI_IBS_WAKE_IND in rx state %d",
                       qca->rx_ibs_state);
                break;
        }

        spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);

        /* Actually send the packets */
        hci_uart_tx_wakeup(hu);
}

/* Called upon a sleep-indication from the device.
 */
static void device_want_to_sleep(struct hci_uart *hu)
{
        unsigned long flags;
        struct qca_data *qca = hu->priv;

        BT_DBG("hu %p want to sleep", hu);

        spin_lock_irqsave(&qca->hci_ibs_lock, flags);

        qca->ibs_recv_slps++;

        switch (qca->rx_ibs_state) {
        case HCI_IBS_RX_AWAKE:
                /* Update state */
                qca->rx_ibs_state = HCI_IBS_RX_ASLEEP;
                /* Vote off rx clock under workqueue */
                queue_work(qca->workqueue, &qca->ws_rx_vote_off);
                break;

        case HCI_IBS_RX_ASLEEP:
                /* Fall through */

        default:
                /* Any other state is illegal */
                BT_ERR("Received HCI_IBS_SLEEP_IND in rx state %d",
                       qca->rx_ibs_state);
                break;
        }

        spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
}

/* Called upon wake-up-acknowledgement from the device
 */
static void device_woke_up(struct hci_uart *hu)
{
        unsigned long flags, idle_delay;
        struct qca_data *qca = hu->priv;
        struct sk_buff *skb = NULL;

        BT_DBG("hu %p woke up", hu);

        spin_lock_irqsave(&qca->hci_ibs_lock, flags);

        qca->ibs_recv_wacks++;

        switch (qca->tx_ibs_state) {
        case HCI_IBS_TX_AWAKE:
                /* Expect one if we send 2 WAKEs */
                BT_DBG("Received HCI_IBS_WAKE_ACK in tx state %d",
                       qca->tx_ibs_state);
                break;

        case HCI_IBS_TX_WAKING:
                /* Send pending packets */
                while ((skb = skb_dequeue(&qca->tx_wait_q)))
                        skb_queue_tail(&qca->txq, skb);

                /* Switch timers and change state to HCI_IBS_TX_AWAKE */
                del_timer(&qca->wake_retrans_timer);
                idle_delay = msecs_to_jiffies(qca->tx_idle_delay);
                mod_timer(&qca->tx_idle_timer, jiffies + idle_delay);
                qca->tx_ibs_state = HCI_IBS_TX_AWAKE;
                break;

        case HCI_IBS_TX_ASLEEP:
                /* Fall through */

        default:
                BT_ERR("Received HCI_IBS_WAKE_ACK in tx state %d",
                       qca->tx_ibs_state);
                break;
        }

        spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);

        /* Actually send the packets */
        hci_uart_tx_wakeup(hu);
}

/* Enqueue frame for transmittion (padding, crc, etc) may be called from
 * two simultaneous tasklets.
 */
static int qca_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
        unsigned long flags = 0, idle_delay;
        struct qca_data *qca = hu->priv;

        BT_DBG("hu %p qca enq skb %p tx_ibs_state %d", hu, skb,
               qca->tx_ibs_state);

        /* Prepend skb with frame type */
        memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);

        /* Don't go to sleep in middle of patch download or
         * Out-Of-Band(GPIOs control) sleep is selected.
         */
        if (!test_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags)) {
                skb_queue_tail(&qca->txq, skb);
                return 0;
        }

        spin_lock_irqsave(&qca->hci_ibs_lock, flags);

        /* Act according to current state */
        switch (qca->tx_ibs_state) {
        case HCI_IBS_TX_AWAKE:
                BT_DBG("Device awake, sending normally");
                skb_queue_tail(&qca->txq, skb);
                idle_delay = msecs_to_jiffies(qca->tx_idle_delay);
                mod_timer(&qca->tx_idle_timer, jiffies + idle_delay);
                break;

        case HCI_IBS_TX_ASLEEP:
                BT_DBG("Device asleep, waking up and queueing packet");
                /* Save packet for later */
                skb_queue_tail(&qca->tx_wait_q, skb);

                qca->tx_ibs_state = HCI_IBS_TX_WAKING;
                /* Schedule a work queue to wake up device */
                queue_work(qca->workqueue, &qca->ws_awake_device);
                break;

        case HCI_IBS_TX_WAKING:
                BT_DBG("Device waking up, queueing packet");
                /* Transient state; just keep packet for later */
                skb_queue_tail(&qca->tx_wait_q, skb);
                break;

        default:
                BT_ERR("Illegal tx state: %d (losing packet)",
                       qca->tx_ibs_state);
                kfree_skb(skb);
                break;
        }

        spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);

        return 0;
}

static int qca_ibs_sleep_ind(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);

        BT_DBG("hu %p recv hci ibs cmd 0x%x", hu, HCI_IBS_SLEEP_IND);

        device_want_to_sleep(hu);

        kfree_skb(skb);
        return 0;
}

static int qca_ibs_wake_ind(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);

        BT_DBG("hu %p recv hci ibs cmd 0x%x", hu, HCI_IBS_WAKE_IND);

        device_want_to_wakeup(hu);

        kfree_skb(skb);
        return 0;
}

static int qca_ibs_wake_ack(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);

        BT_DBG("hu %p recv hci ibs cmd 0x%x", hu, HCI_IBS_WAKE_ACK);

        device_woke_up(hu);

        kfree_skb(skb);
        return 0;
}

#define QCA_IBS_SLEEP_IND_EVENT \
        .type = HCI_IBS_SLEEP_IND, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = HCI_MAX_IBS_SIZE

#define QCA_IBS_WAKE_IND_EVENT \
        .type = HCI_IBS_WAKE_IND, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = HCI_MAX_IBS_SIZE

#define QCA_IBS_WAKE_ACK_EVENT \
        .type = HCI_IBS_WAKE_ACK, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = HCI_MAX_IBS_SIZE

static const struct h4_recv_pkt qca_recv_pkts[] = {
        { H4_RECV_ACL,             .recv = hci_recv_frame    },
        { H4_RECV_SCO,             .recv = hci_recv_frame    },
        { H4_RECV_EVENT,           .recv = hci_recv_frame    },
        { QCA_IBS_WAKE_IND_EVENT,  .recv = qca_ibs_wake_ind  },
        { QCA_IBS_WAKE_ACK_EVENT,  .recv = qca_ibs_wake_ack  },
        { QCA_IBS_SLEEP_IND_EVENT, .recv = qca_ibs_sleep_ind },
};

static int qca_recv(struct hci_uart *hu, const void *data, int count)
{
        struct qca_data *qca = hu->priv;

        if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
                return -EUNATCH;

        qca->rx_skb = h4_recv_buf(hu->hdev, qca->rx_skb, data, count,
                                  qca_recv_pkts, ARRAY_SIZE(qca_recv_pkts));
        if (IS_ERR(qca->rx_skb)) {
                int err = PTR_ERR(qca->rx_skb);
                BT_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, err);
                qca->rx_skb = NULL;
                return err;
        }

        return count;
}

static struct sk_buff *qca_dequeue(struct hci_uart *hu)
{
        struct qca_data *qca = hu->priv;

        return skb_dequeue(&qca->txq);
}

static uint8_t qca_get_baudrate_value(int speed)
{
        switch (speed) {
        case 9600:
                return QCA_BAUDRATE_9600;
        case 19200:
                return QCA_BAUDRATE_19200;
        case 38400:
                return QCA_BAUDRATE_38400;
        case 57600:
                return QCA_BAUDRATE_57600;
        case 115200:
                return QCA_BAUDRATE_115200;
        case 230400:
                return QCA_BAUDRATE_230400;
        case 460800:
                return QCA_BAUDRATE_460800;
        case 500000:
                return QCA_BAUDRATE_500000;
        case 921600:
                return QCA_BAUDRATE_921600;
        case 1000000:
                return QCA_BAUDRATE_1000000;
        case 2000000:
                return QCA_BAUDRATE_2000000;
        case 3000000:
                return QCA_BAUDRATE_3000000;
        case 3500000:
                return QCA_BAUDRATE_3500000;
        default:
                return QCA_BAUDRATE_115200;
        }
}

static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);
        struct qca_data *qca = hu->priv;
        struct sk_buff *skb;
        u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 };

        if (baudrate > QCA_BAUDRATE_3000000)
                return -EINVAL;

        cmd[4] = baudrate;

        skb = bt_skb_alloc(sizeof(cmd), GFP_ATOMIC);
        if (!skb) {
                BT_ERR("Failed to allocate memory for baudrate packet");
                return -ENOMEM;
        }

        /* Assign commands to change baudrate and packet type. */
        memcpy(skb_put(skb, sizeof(cmd)), cmd, sizeof(cmd));
        hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;

        skb_queue_tail(&qca->txq, skb);
        hci_uart_tx_wakeup(hu);

        /* wait 300ms to change new baudrate on controller side
         * controller will come back after they receive this HCI command
         * then host can communicate with new baudrate to controller
         */
        set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
        set_current_state(TASK_INTERRUPTIBLE);

        return 0;
}

static int qca_setup(struct hci_uart *hu)
{
        struct hci_dev *hdev = hu->hdev;
        struct qca_data *qca = hu->priv;
        unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
        int ret;

        BT_INFO("%s: ROME setup", hdev->name);

        /* Patch downloading has to be done without IBS mode */
        clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);

        /* Setup initial baudrate */
        speed = 0;
        if (hu->init_speed)
                speed = hu->init_speed;
        else if (hu->proto->init_speed)
                speed = hu->proto->init_speed;

        if (speed)
                hci_uart_set_baudrate(hu, speed);

        /* Setup user speed if needed */
        speed = 0;
        if (hu->oper_speed)
                speed = hu->oper_speed;
        else if (hu->proto->oper_speed)
                speed = hu->proto->oper_speed;

        if (speed) {
                qca_baudrate = qca_get_baudrate_value(speed);

                BT_INFO("%s: Set UART speed to %d", hdev->name, speed);
                ret = qca_set_baudrate(hdev, qca_baudrate);
                if (ret) {
                        BT_ERR("%s: Failed to change the baud rate (%d)",
                               hdev->name, ret);
                        return ret;
                }
                hci_uart_set_baudrate(hu, speed);
        }

        /* Setup patch / NVM configurations */
        ret = qca_uart_setup_rome(hdev, qca_baudrate);
        if (!ret) {
                set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
                qca_debugfs_init(hdev);
        }

        /* Setup bdaddr */
        hu->hdev->set_bdaddr = qca_set_bdaddr_rome;

        return ret;
}

static struct hci_uart_proto qca_proto = {
        .id             = HCI_UART_QCA,
        .name           = "QCA",
        .manufacturer   = 29,
        .init_speed     = 115200,
        .oper_speed     = 3000000,
        .open           = qca_open,
        .close          = qca_close,
        .flush          = qca_flush,
        .setup          = qca_setup,
        .recv           = qca_recv,
        .enqueue        = qca_enqueue,
        .dequeue        = qca_dequeue,
};

int __init qca_init(void)
{
        return hci_uart_register_proto(&qca_proto);
}

int __exit qca_deinit(void)
{
        return hci_uart_unregister_proto(&qca_proto);
}