root/drivers/bluetooth/btnxpuart.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  NXP Bluetooth driver
 *  Copyright 2023-2025 NXP
 */

#include <linux/module.h>
#include <linux/kernel.h>

#include <linux/serdev.h>
#include <linux/of.h>
#include <linux/skbuff.h>
#include <linux/unaligned.h>
#include <linux/firmware.h>
#include <linux/string.h>
#include <linux/crc8.h>
#include <linux/crc32.h>
#include <linux/string_helpers.h>
#include <linux/gpio/consumer.h>
#include <linux/of_irq.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>

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

#include "hci_uart.h"

#define MANUFACTURER_NXP                37

#define BTNXPUART_TX_STATE_ACTIVE       1
#define BTNXPUART_FW_DOWNLOADING        2
#define BTNXPUART_CHECK_BOOT_SIGNATURE  3
#define BTNXPUART_SERDEV_OPEN           4
#define BTNXPUART_IR_IN_PROGRESS        5
#define BTNXPUART_FW_DOWNLOAD_ABORT     6
#define BTNXPUART_FW_DUMP_IN_PROGRESS   7

/* NXP HW err codes */
#define BTNXPUART_IR_HW_ERR             0xb0

#define FIRMWARE_W8987          "uart8987_bt.bin"
#define FIRMWARE_W8987_OLD      "uartuart8987_bt.bin"
#define FIRMWARE_W8997          "uart8997_bt_v4.bin"
#define FIRMWARE_W8997_OLD      "uartuart8997_bt_v4.bin"
#define FIRMWARE_W9098          "uart9098_bt_v1.bin"
#define FIRMWARE_W9098_OLD      "uartuart9098_bt_v1.bin"
#define FIRMWARE_IW416          "uartiw416_bt.bin"
#define FIRMWARE_IW416_OLD      "uartiw416_bt_v0.bin"
#define FIRMWARE_IW612          "uartspi_n61x_v1.bin.se"
#define FIRMWARE_IW610          "uartspi_iw610.bin"
#define FIRMWARE_SECURE_IW610   "uartspi_iw610.bin.se"
#define FIRMWARE_IW624          "uartiw624_bt.bin"
#define FIRMWARE_SECURE_IW624   "uartiw624_bt.bin.se"
#define FIRMWARE_AW693          "uartaw693_bt.bin"
#define FIRMWARE_SECURE_AW693   "uartaw693_bt.bin.se"
#define FIRMWARE_AW693_A1               "uartaw693_bt_v1.bin"
#define FIRMWARE_SECURE_AW693_A1        "uartaw693_bt_v1.bin.se"
#define FIRMWARE_HELPER         "helper_uart_3000000.bin"

#define CHIP_ID_W9098           0x5c03
#define CHIP_ID_IW416           0x7201
#define CHIP_ID_IW612           0x7601
#define CHIP_ID_IW624a          0x8000
#define CHIP_ID_IW624c          0x8001
#define CHIP_ID_AW693a0         0x8200
#define CHIP_ID_AW693a1         0x8201
#define CHIP_ID_IW610a0         0x8800
#define CHIP_ID_IW610a1         0x8801

#define FW_SECURE_MASK          0xc0
#define FW_OPEN                 0x00
#define FW_AUTH_ILLEGAL         0x40
#define FW_AUTH_PLAIN           0x80
#define FW_AUTH_ENC             0xc0

#define HCI_NXP_PRI_BAUDRATE    115200
#define HCI_NXP_SEC_BAUDRATE_3M 3000000
#define HCI_NXP_SEC_BAUDRATE_4M 4000000

#define MAX_FW_FILE_NAME_LEN    50

/* Default ps timeout period in milliseconds */
#define PS_DEFAULT_TIMEOUT_PERIOD_MS     2000

/* wakeup methods */
#define WAKEUP_METHOD_DTR       0
#define WAKEUP_METHOD_BREAK     1
#define WAKEUP_METHOD_EXT_BREAK 2
#define WAKEUP_METHOD_RTS       3
#define WAKEUP_METHOD_GPIO      4
#define WAKEUP_METHOD_INVALID   0xff

/* power save mode status */
#define PS_MODE_DISABLE         0
#define PS_MODE_ENABLE          1

/* Power Save Commands to ps_work_func  */
#define PS_CMD_EXIT_PS          1
#define PS_CMD_ENTER_PS         2

/* power save state */
#define PS_STATE_AWAKE          0
#define PS_STATE_SLEEP          1

/* NXP Vendor Commands. Refer user manual UM11628 on nxp.com */
/* Set custom BD Address */
#define HCI_NXP_SET_BD_ADDR     0xfc22
/* Set Auto-Sleep mode */
#define HCI_NXP_AUTO_SLEEP_MODE 0xfc23
/* Set Wakeup method */
#define HCI_NXP_WAKEUP_METHOD   0xfc53
/* Set operational baudrate */
#define HCI_NXP_SET_OPER_SPEED  0xfc09
/* Independent Reset (Soft Reset) */
#define HCI_NXP_IND_RESET       0xfcfc
/* Bluetooth vendor command: Trigger FW dump */
#define HCI_NXP_TRIGGER_DUMP    0xfe91

/* Bluetooth Power State : Vendor cmd params */
#define BT_PS_ENABLE                    0x02
#define BT_PS_DISABLE                   0x03

/* Bluetooth Host Wakeup Methods */
#define BT_HOST_WAKEUP_METHOD_NONE      0x00
#define BT_HOST_WAKEUP_METHOD_DTR       0x01
#define BT_HOST_WAKEUP_METHOD_BREAK     0x02
#define BT_HOST_WAKEUP_METHOD_GPIO      0x03

/* Bluetooth Chip Wakeup Methods */
#define BT_CTRL_WAKEUP_METHOD_DSR       0x00
#define BT_CTRL_WAKEUP_METHOD_BREAK     0x01
#define BT_CTRL_WAKEUP_METHOD_GPIO      0x02
#define BT_CTRL_WAKEUP_METHOD_EXT_BREAK 0x04
#define BT_CTRL_WAKEUP_METHOD_RTS       0x05

struct ps_data {
        u8    target_ps_mode;   /* ps mode to be set */
        u8    cur_psmode;       /* current ps_mode */
        u8    ps_state;         /* controller's power save state */
        u8    ps_cmd;
        u8    h2c_wakeupmode;
        u8    cur_h2c_wakeupmode;
        u8    c2h_wakeupmode;
        u8    c2h_wakeup_gpio;
        u8    h2c_wakeup_gpio;
        bool  driver_sent_cmd;
        u16   h2c_ps_interval;
        u16   c2h_ps_interval;
        bool  wakeup_source;
        struct gpio_desc *h2c_ps_gpio;
        s32 irq_handler;
        struct hci_dev *hdev;
        struct work_struct work;
        struct timer_list ps_timer;
        struct mutex ps_lock;
};

struct wakeup_cmd_payload {
        u8 c2h_wakeupmode;
        u8 c2h_wakeup_gpio;
        u8 h2c_wakeupmode;
        u8 h2c_wakeup_gpio;
} __packed;

struct psmode_cmd_payload {
        u8 ps_cmd;
        __le16 c2h_ps_interval;
} __packed;

struct btnxpuart_data {
        const char *helper_fw_name;
        const char *fw_name;
        const char *fw_name_old;
};

enum bootloader_param_change {
        not_changed,
        cmd_sent,
        changed
};

struct btnxpuart_dev {
        struct hci_dev *hdev;
        struct serdev_device *serdev;

        struct work_struct tx_work;
        unsigned long tx_state;
        struct sk_buff_head txq;
        struct sk_buff *rx_skb;

        const struct firmware *fw;
        u8 fw_name[MAX_FW_FILE_NAME_LEN];
        u32 fw_dnld_v1_offset;
        u32 fw_v1_sent_bytes;
        u32 fw_dnld_v3_offset;
        u32 fw_v3_offset_correction;
        u32 fw_v3_prev_sent;
        u32 fw_v1_expected_len;
        u32 boot_reg_offset;
        wait_queue_head_t fw_dnld_done_wait_q;
        wait_queue_head_t check_boot_sign_wait_q;

        u32 new_baudrate;
        u32 current_baudrate;
        u32 fw_init_baudrate;
        u32 secondary_baudrate;
        enum bootloader_param_change timeout_changed;
        enum bootloader_param_change baudrate_changed;
        bool helper_downloaded;

        struct ps_data psdata;
        struct btnxpuart_data *nxp_data;
        struct reset_control *pdn;
        struct hci_uart hu;
};

#define NXP_V1_FW_REQ_PKT       0xa5
#define NXP_V1_CHIP_VER_PKT     0xaa
#define NXP_V3_FW_REQ_PKT       0xa7
#define NXP_V3_CHIP_VER_PKT     0xab

#define NXP_ACK_V1              0x5a
#define NXP_NAK_V1              0xbf
#define NXP_ACK_V3              0x7a
#define NXP_NAK_V3              0x7b
#define NXP_CRC_ERROR_V3        0x7c

/* Bootloader signature error codes: Refer AN12820 from nxp.com */
#define NXP_CRC_RX_ERROR        BIT(0)  /* CRC error in previous packet */
#define NXP_ACK_RX_TIMEOUT      BIT(2)  /* ACK not received from host */
#define NXP_HDR_RX_TIMEOUT      BIT(3)  /* FW Header chunk not received */
#define NXP_DATA_RX_TIMEOUT     BIT(4)  /* FW Data chunk not received */

#define HDR_LEN                 16

#define NXP_RECV_CHIP_VER_V1 \
        .type = NXP_V1_CHIP_VER_PKT, \
        .hlen = 4, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 4

#define NXP_RECV_FW_REQ_V1 \
        .type = NXP_V1_FW_REQ_PKT, \
        .hlen = 4, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 4

#define NXP_RECV_CHIP_VER_V3 \
        .type = NXP_V3_CHIP_VER_PKT, \
        .hlen = 4, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 4

#define NXP_RECV_FW_REQ_V3 \
        .type = NXP_V3_FW_REQ_PKT, \
        .hlen = 9, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 9

struct v1_data_req {
        __le16 len;
        __le16 len_comp;
} __packed;

struct v1_start_ind {
        __le16 chip_id;
        __le16 chip_id_comp;
} __packed;

struct v3_data_req {
        __le16 len;
        __le32 offset;
        __le16 error;
        u8 crc;
} __packed;

struct v3_start_ind {
        __le16 chip_id;
        u8 loader_ver;
        u8 crc;
} __packed;

/* UART register addresses of BT chip */
#define CLKDIVADDR      0x7f00008f
#define UARTDIVADDR     0x7f000090
#define UARTMCRADDR     0x7f000091
#define UARTREINITADDR  0x7f000092
#define UARTICRADDR     0x7f000093
#define UARTFCRADDR     0x7f000094

#define MCR             0x00000022
#define INIT            0x00000001
#define ICR             0x000000c7
#define FCR             0x000000c7

#define POLYNOMIAL8     0x07

struct uart_reg {
        __le32 address;
        __le32 value;
} __packed;

struct uart_config {
        struct uart_reg clkdiv;
        struct uart_reg uartdiv;
        struct uart_reg mcr;
        struct uart_reg re_init;
        struct uart_reg icr;
        struct uart_reg fcr;
        __be32 crc;
} __packed;

struct nxp_bootloader_cmd {
        __le32 header;
        __le32 arg;
        __le32 payload_len;
        __be32 crc;
} __packed;

struct nxp_v3_rx_timeout_nak {
        u8 nak;
        __le32 offset;
        u8 crc;
} __packed;

union nxp_v3_rx_timeout_nak_u {
        struct nxp_v3_rx_timeout_nak pkt;
        u8 buf[6];
};

struct nxp_v3_crc_nak {
        u8 nak;
        u8 crc;
} __packed;

union nxp_v3_crc_nak_u {
        struct nxp_v3_crc_nak pkt;
        u8 buf[2];
};

/* FW dump */
#define NXP_FW_DUMP_SIZE        (1024 * 1000)

struct nxp_fw_dump_hdr {
        __le16 seq_num;
        __le16 reserved;
        __le16 buf_type;
        __le16 buf_len;
};

union nxp_set_bd_addr_payload {
        struct {
                u8 param_id;
                u8 param_len;
                u8 param[6];
        } __packed data;
        u8 buf[8];
};

static u8 crc8_table[CRC8_TABLE_SIZE];

/* Default configurations */
#define DEFAULT_H2C_WAKEUP_MODE WAKEUP_METHOD_BREAK
#define DEFAULT_PS_MODE         PS_MODE_ENABLE
#define FW_INIT_BAUDRATE        HCI_NXP_PRI_BAUDRATE

static struct sk_buff *nxp_drv_send_cmd(struct hci_dev *hdev, u16 opcode,
                                        u32 plen,
                                        void *param,
                                        bool resp)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;
        struct sk_buff *skb = NULL;

        /* set flag to prevent nxp_enqueue from parsing values from this command and
         * calling hci_cmd_sync_queue() again.
         */
        psdata->driver_sent_cmd = true;
        if (resp) {
                skb = __hci_cmd_sync(hdev, opcode, plen, param, HCI_CMD_TIMEOUT);
        } else {
                __hci_cmd_send(hdev, opcode, plen, param);
                /* Allow command to be sent before tx_work is cancelled
                 * by btnxpuart_flush()
                 */
                msleep(20);
        }
        psdata->driver_sent_cmd = false;

        return skb;
}

static void btnxpuart_tx_wakeup(struct btnxpuart_dev *nxpdev)
{
        if (schedule_work(&nxpdev->tx_work))
                set_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state);
}

/* NXP Power Save Feature */
static void ps_start_timer(struct btnxpuart_dev *nxpdev)
{
        struct ps_data *psdata = &nxpdev->psdata;

        if (!psdata)
                return;

        if (psdata->cur_psmode == PS_MODE_ENABLE)
                mod_timer(&psdata->ps_timer, jiffies + msecs_to_jiffies(psdata->h2c_ps_interval));

        if (psdata->ps_state == PS_STATE_AWAKE && psdata->ps_cmd == PS_CMD_ENTER_PS)
                cancel_work_sync(&psdata->work);
}

static void ps_cancel_timer(struct btnxpuart_dev *nxpdev)
{
        struct ps_data *psdata = &nxpdev->psdata;

        flush_work(&psdata->work);
        timer_shutdown_sync(&psdata->ps_timer);
}

static void ps_control(struct hci_dev *hdev, u8 ps_state)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;
        int status = 0;

        if (psdata->ps_state == ps_state ||
            !test_bit(BTNXPUART_SERDEV_OPEN, &nxpdev->tx_state))
                return;

        mutex_lock(&psdata->ps_lock);
        switch (psdata->cur_h2c_wakeupmode) {
        case WAKEUP_METHOD_GPIO:
                if (ps_state == PS_STATE_AWAKE)
                        gpiod_set_value_cansleep(psdata->h2c_ps_gpio, 0);
                else
                        gpiod_set_value_cansleep(psdata->h2c_ps_gpio, 1);
                bt_dev_dbg(hdev, "Set h2c_ps_gpio: %s",
                           str_high_low(ps_state == PS_STATE_SLEEP));
                break;
        case WAKEUP_METHOD_DTR:
                if (ps_state == PS_STATE_AWAKE)
                        status = serdev_device_set_tiocm(nxpdev->serdev, TIOCM_DTR, 0);
                else
                        status = serdev_device_set_tiocm(nxpdev->serdev, 0, TIOCM_DTR);
                break;
        case WAKEUP_METHOD_BREAK:
        default:
                if (ps_state == PS_STATE_AWAKE)
                        status = serdev_device_break_ctl(nxpdev->serdev, 0);
                else
                        status = serdev_device_break_ctl(nxpdev->serdev, -1);
                msleep(20); /* Allow chip to detect UART-break and enter sleep */
                bt_dev_dbg(hdev, "Set UART break: %s, status=%d",
                           str_on_off(ps_state == PS_STATE_SLEEP), status);
                break;
        }
        if (!status)
                psdata->ps_state = ps_state;
        mutex_unlock(&psdata->ps_lock);

        if (ps_state == PS_STATE_AWAKE)
                btnxpuart_tx_wakeup(nxpdev);
}

static void ps_work_func(struct work_struct *work)
{
        struct ps_data *data = container_of(work, struct ps_data, work);

        if (data->ps_cmd == PS_CMD_ENTER_PS && data->cur_psmode == PS_MODE_ENABLE)
                ps_control(data->hdev, PS_STATE_SLEEP);
        else if (data->ps_cmd == PS_CMD_EXIT_PS)
                ps_control(data->hdev, PS_STATE_AWAKE);
}

static void ps_timeout_func(struct timer_list *t)
{
        struct ps_data *data = timer_container_of(data, t, ps_timer);
        struct hci_dev *hdev = data->hdev;
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);

        if (test_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state)) {
                ps_start_timer(nxpdev);
        } else {
                data->ps_cmd = PS_CMD_ENTER_PS;
                schedule_work(&data->work);
        }
}

static irqreturn_t ps_host_wakeup_irq_handler(int irq, void *priv)
{
        struct btnxpuart_dev *nxpdev = (struct btnxpuart_dev *)priv;

        bt_dev_dbg(nxpdev->hdev, "Host wakeup interrupt");
        return IRQ_HANDLED;
}
static int ps_setup(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct serdev_device *serdev = nxpdev->serdev;
        struct ps_data *psdata = &nxpdev->psdata;
        int ret;

        /* Out-Of-Band Device Wakeup */
        psdata->h2c_ps_gpio = devm_gpiod_get_optional(&serdev->dev, "device-wakeup",
                                                      GPIOD_OUT_LOW);
        if (IS_ERR(psdata->h2c_ps_gpio)) {
                bt_dev_err(hdev, "Error fetching device-wakeup-gpios: %ld",
                           PTR_ERR(psdata->h2c_ps_gpio));
                return PTR_ERR(psdata->h2c_ps_gpio);
        }

        if (device_property_read_u8(&serdev->dev, "nxp,wakein-pin", &psdata->h2c_wakeup_gpio)) {
                psdata->h2c_wakeup_gpio = 0xff; /* 0xff: use default pin/gpio */
        } else if (!psdata->h2c_ps_gpio) {
                bt_dev_warn(hdev, "nxp,wakein-pin property without device-wakeup-gpios");
                psdata->h2c_wakeup_gpio = 0xff;
        }

        /* Out-Of-Band Host Wakeup */
        if (of_property_read_bool(serdev->dev.of_node, "wakeup-source")) {
                psdata->irq_handler = of_irq_get_byname(serdev->dev.of_node, "wakeup");
                bt_dev_info(nxpdev->hdev, "irq_handler: %d", psdata->irq_handler);
                if (psdata->irq_handler > 0)
                        psdata->wakeup_source = true;
        }

        if (device_property_read_u8(&serdev->dev, "nxp,wakeout-pin", &psdata->c2h_wakeup_gpio)) {
                psdata->c2h_wakeup_gpio = 0xff;
                if (psdata->wakeup_source) {
                        bt_dev_warn(hdev, "host wakeup interrupt without nxp,wakeout-pin");
                        psdata->wakeup_source = false;
                }
        } else if (!psdata->wakeup_source) {
                bt_dev_warn(hdev, "nxp,wakeout-pin property without host wakeup interrupt");
                psdata->c2h_wakeup_gpio = 0xff;
        }

        if (psdata->wakeup_source) {
                ret = devm_request_threaded_irq(&serdev->dev, psdata->irq_handler,
                                                NULL, ps_host_wakeup_irq_handler,
                                                IRQF_ONESHOT,
                                                dev_name(&serdev->dev), nxpdev);
                if (ret)
                        bt_dev_info(hdev, "error setting wakeup IRQ handler, ignoring\n");
                disable_irq(psdata->irq_handler);
                device_init_wakeup(&serdev->dev, true);
        }

        psdata->hdev = hdev;
        INIT_WORK(&psdata->work, ps_work_func);
        mutex_init(&psdata->ps_lock);
        timer_setup(&psdata->ps_timer, ps_timeout_func, 0);

        return 0;
}

static bool ps_wakeup(struct btnxpuart_dev *nxpdev)
{
        struct ps_data *psdata = &nxpdev->psdata;
        u8 ps_state;

        mutex_lock(&psdata->ps_lock);
        ps_state = psdata->ps_state;
        mutex_unlock(&psdata->ps_lock);

        if (ps_state != PS_STATE_AWAKE) {
                psdata->ps_cmd = PS_CMD_EXIT_PS;
                schedule_work(&psdata->work);
                return true;
        }
        return false;
}

static void ps_cleanup(struct btnxpuart_dev *nxpdev)
{
        struct ps_data *psdata = &nxpdev->psdata;
        u8 ps_state;

        mutex_lock(&psdata->ps_lock);
        ps_state = psdata->ps_state;
        mutex_unlock(&psdata->ps_lock);

        if (ps_state != PS_STATE_AWAKE)
                ps_control(psdata->hdev, PS_STATE_AWAKE);

        ps_cancel_timer(nxpdev);
        cancel_work_sync(&psdata->work);
        mutex_destroy(&psdata->ps_lock);
}

static int send_ps_cmd(struct hci_dev *hdev, void *data)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;
        struct psmode_cmd_payload pcmd;
        struct sk_buff *skb;
        u8 *status;

        if (psdata->target_ps_mode == PS_MODE_ENABLE)
                pcmd.ps_cmd = BT_PS_ENABLE;
        else
                pcmd.ps_cmd = BT_PS_DISABLE;
        pcmd.c2h_ps_interval = __cpu_to_le16(psdata->c2h_ps_interval);

        skb = nxp_drv_send_cmd(hdev, HCI_NXP_AUTO_SLEEP_MODE, sizeof(pcmd),
                               &pcmd, true);
        if (IS_ERR(skb)) {
                bt_dev_err(hdev, "Setting Power Save mode failed (%ld)", PTR_ERR(skb));
                return PTR_ERR(skb);
        }

        status = skb_pull_data(skb, 1);
        if (status) {
                if (!*status)
                        psdata->cur_psmode = psdata->target_ps_mode;
                else
                        psdata->target_ps_mode = psdata->cur_psmode;
                if (psdata->cur_psmode == PS_MODE_ENABLE)
                        ps_start_timer(nxpdev);
                else
                        ps_wakeup(nxpdev);
                bt_dev_dbg(hdev, "Power Save mode response: status=%d, ps_mode=%d",
                           *status, psdata->cur_psmode);
        }
        kfree_skb(skb);

        return 0;
}

static int send_wakeup_method_cmd(struct hci_dev *hdev, void *data)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;
        struct wakeup_cmd_payload pcmd;
        struct sk_buff *skb;
        u8 *status;

        pcmd.c2h_wakeupmode = psdata->c2h_wakeupmode;
        pcmd.c2h_wakeup_gpio = psdata->c2h_wakeup_gpio;
        pcmd.h2c_wakeup_gpio = 0xff;
        switch (psdata->h2c_wakeupmode) {
        case WAKEUP_METHOD_GPIO:
                pcmd.h2c_wakeupmode = BT_CTRL_WAKEUP_METHOD_GPIO;
                pcmd.h2c_wakeup_gpio = psdata->h2c_wakeup_gpio;
                break;
        case WAKEUP_METHOD_DTR:
                pcmd.h2c_wakeupmode = BT_CTRL_WAKEUP_METHOD_DSR;
                break;
        case WAKEUP_METHOD_BREAK:
        default:
                pcmd.h2c_wakeupmode = BT_CTRL_WAKEUP_METHOD_BREAK;
                break;
        }

        skb = nxp_drv_send_cmd(hdev, HCI_NXP_WAKEUP_METHOD, sizeof(pcmd),
                               &pcmd, true);
        if (IS_ERR(skb)) {
                bt_dev_err(hdev, "Setting wake-up method failed (%ld)", PTR_ERR(skb));
                return PTR_ERR(skb);
        }

        status = skb_pull_data(skb, 1);
        if (status) {
                if (*status == 0)
                        psdata->cur_h2c_wakeupmode = psdata->h2c_wakeupmode;
                else
                        psdata->h2c_wakeupmode = psdata->cur_h2c_wakeupmode;
                bt_dev_dbg(hdev, "Set Wakeup Method response: status=%d, h2c_wakeupmode=%d",
                           *status, psdata->cur_h2c_wakeupmode);
        }
        kfree_skb(skb);

        return 0;
}

static void ps_init(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;
        u8 default_h2c_wakeup_mode = DEFAULT_H2C_WAKEUP_MODE;

        serdev_device_set_tiocm(nxpdev->serdev, 0, TIOCM_RTS);
        usleep_range(5000, 10000);
        serdev_device_set_tiocm(nxpdev->serdev, TIOCM_RTS, 0);
        usleep_range(5000, 10000);

        psdata->ps_state = PS_STATE_AWAKE;

        if (psdata->c2h_wakeup_gpio != 0xff)
                psdata->c2h_wakeupmode = BT_HOST_WAKEUP_METHOD_GPIO;
        else
                psdata->c2h_wakeupmode = BT_HOST_WAKEUP_METHOD_NONE;

        psdata->cur_h2c_wakeupmode = WAKEUP_METHOD_INVALID;
        if (psdata->h2c_ps_gpio)
                default_h2c_wakeup_mode = WAKEUP_METHOD_GPIO;

        psdata->h2c_ps_interval = PS_DEFAULT_TIMEOUT_PERIOD_MS;

        switch (default_h2c_wakeup_mode) {
        case WAKEUP_METHOD_GPIO:
                psdata->h2c_wakeupmode = WAKEUP_METHOD_GPIO;
                gpiod_set_value_cansleep(psdata->h2c_ps_gpio, 0);
                usleep_range(5000, 10000);
                break;
        case WAKEUP_METHOD_DTR:
                psdata->h2c_wakeupmode = WAKEUP_METHOD_DTR;
                serdev_device_set_tiocm(nxpdev->serdev, 0, TIOCM_DTR);
                serdev_device_set_tiocm(nxpdev->serdev, TIOCM_DTR, 0);
                break;
        case WAKEUP_METHOD_BREAK:
        default:
                psdata->h2c_wakeupmode = WAKEUP_METHOD_BREAK;
                serdev_device_break_ctl(nxpdev->serdev, -1);
                usleep_range(5000, 10000);
                serdev_device_break_ctl(nxpdev->serdev, 0);
                usleep_range(5000, 10000);
                break;
        }

        psdata->cur_psmode = PS_MODE_DISABLE;
        psdata->target_ps_mode = DEFAULT_PS_MODE;
}

/* NXP Firmware Download Feature */
static int nxp_download_firmware(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        int err = 0;

        nxpdev->fw_dnld_v1_offset = 0;
        nxpdev->fw_v1_sent_bytes = 0;
        nxpdev->fw_v1_expected_len = HDR_LEN;
        nxpdev->boot_reg_offset = 0;
        nxpdev->fw_dnld_v3_offset = 0;
        nxpdev->fw_v3_offset_correction = 0;
        nxpdev->baudrate_changed = not_changed;
        nxpdev->timeout_changed = not_changed;
        nxpdev->helper_downloaded = false;

        serdev_device_set_baudrate(nxpdev->serdev, HCI_NXP_PRI_BAUDRATE);
        serdev_device_set_flow_control(nxpdev->serdev, false);
        nxpdev->current_baudrate = HCI_NXP_PRI_BAUDRATE;

        /* Wait till FW is downloaded */
        err = wait_event_interruptible_timeout(nxpdev->fw_dnld_done_wait_q,
                                               !test_bit(BTNXPUART_FW_DOWNLOADING,
                                                         &nxpdev->tx_state),
                                               msecs_to_jiffies(60000));

        if (nxpdev->fw && strlen(nxpdev->fw_name)) {
                release_firmware(nxpdev->fw);
                memset(nxpdev->fw_name, 0, sizeof(nxpdev->fw_name));
        }

        if (err == 0) {
                bt_dev_err(hdev, "FW Download Timeout. offset: %d",
                                nxpdev->fw_dnld_v1_offset ?
                                nxpdev->fw_dnld_v1_offset :
                                nxpdev->fw_dnld_v3_offset);
                return -ETIMEDOUT;
        }
        if (test_bit(BTNXPUART_FW_DOWNLOAD_ABORT, &nxpdev->tx_state)) {
                bt_dev_err(hdev, "FW Download Aborted");
                return -EINTR;
        }

        serdev_device_set_flow_control(nxpdev->serdev, true);

        /* Allow the downloaded FW to initialize */
        msleep(1200);

        return 0;
}

static void nxp_send_ack(u8 ack, struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        u8 ack_nak[2];
        int len = 1;

        ack_nak[0] = ack;
        if (ack == NXP_ACK_V3) {
                ack_nak[1] = crc8(crc8_table, ack_nak, 1, 0xff);
                len = 2;
        }
        serdev_device_write_buf(nxpdev->serdev, ack_nak, len);
}

static bool nxp_fw_change_baudrate(struct hci_dev *hdev, u16 req_len)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct nxp_bootloader_cmd nxp_cmd5;
        struct uart_config uart_config;
        u32 clkdivaddr = CLKDIVADDR - nxpdev->boot_reg_offset;
        u32 uartdivaddr = UARTDIVADDR - nxpdev->boot_reg_offset;
        u32 uartmcraddr = UARTMCRADDR - nxpdev->boot_reg_offset;
        u32 uartreinitaddr = UARTREINITADDR - nxpdev->boot_reg_offset;
        u32 uarticraddr = UARTICRADDR - nxpdev->boot_reg_offset;
        u32 uartfcraddr = UARTFCRADDR - nxpdev->boot_reg_offset;

        if (req_len == sizeof(nxp_cmd5)) {
                nxp_cmd5.header = __cpu_to_le32(5);
                nxp_cmd5.arg = 0;
                nxp_cmd5.payload_len = __cpu_to_le32(sizeof(uart_config));
                /* FW expects swapped CRC bytes */
                nxp_cmd5.crc = __cpu_to_be32(crc32_be(0UL, (char *)&nxp_cmd5,
                                                      sizeof(nxp_cmd5) - 4));

                serdev_device_write_buf(nxpdev->serdev, (u8 *)&nxp_cmd5, sizeof(nxp_cmd5));
                nxpdev->fw_v3_offset_correction += req_len;
        } else if (req_len == sizeof(uart_config)) {
                uart_config.clkdiv.address = __cpu_to_le32(clkdivaddr);
                if (nxpdev->new_baudrate == HCI_NXP_SEC_BAUDRATE_4M)
                        uart_config.clkdiv.value = __cpu_to_le32(0x01000000);
                else
                        uart_config.clkdiv.value = __cpu_to_le32(0x00c00000);
                uart_config.uartdiv.address = __cpu_to_le32(uartdivaddr);
                uart_config.uartdiv.value = __cpu_to_le32(1);
                uart_config.mcr.address = __cpu_to_le32(uartmcraddr);
                uart_config.mcr.value = __cpu_to_le32(MCR);
                uart_config.re_init.address = __cpu_to_le32(uartreinitaddr);
                uart_config.re_init.value = __cpu_to_le32(INIT);
                uart_config.icr.address = __cpu_to_le32(uarticraddr);
                uart_config.icr.value = __cpu_to_le32(ICR);
                uart_config.fcr.address = __cpu_to_le32(uartfcraddr);
                uart_config.fcr.value = __cpu_to_le32(FCR);
                /* FW expects swapped CRC bytes */
                uart_config.crc = __cpu_to_be32(crc32_be(0UL, (char *)&uart_config,
                                                         sizeof(uart_config) - 4));

                serdev_device_write_buf(nxpdev->serdev, (u8 *)&uart_config, sizeof(uart_config));
                serdev_device_wait_until_sent(nxpdev->serdev, 0);
                nxpdev->fw_v3_offset_correction += req_len;
                return true;
        }
        return false;
}

static bool nxp_fw_change_timeout(struct hci_dev *hdev, u16 req_len)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct nxp_bootloader_cmd nxp_cmd7;

        if (req_len != sizeof(nxp_cmd7))
                return false;

        nxp_cmd7.header = __cpu_to_le32(7);
        nxp_cmd7.arg = __cpu_to_le32(0x70);
        nxp_cmd7.payload_len = 0;
        /* FW expects swapped CRC bytes */
        nxp_cmd7.crc = __cpu_to_be32(crc32_be(0UL, (char *)&nxp_cmd7,
                                              sizeof(nxp_cmd7) - 4));
        serdev_device_write_buf(nxpdev->serdev, (u8 *)&nxp_cmd7, sizeof(nxp_cmd7));
        serdev_device_wait_until_sent(nxpdev->serdev, 0);
        nxpdev->fw_v3_offset_correction += req_len;
        return true;
}

static u32 nxp_get_data_len(const u8 *buf)
{
        struct nxp_bootloader_cmd *hdr = (struct nxp_bootloader_cmd *)buf;

        return __le32_to_cpu(hdr->payload_len);
}

static bool is_fw_downloading(struct btnxpuart_dev *nxpdev)
{
        return test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
}

static bool ind_reset_in_progress(struct btnxpuart_dev *nxpdev)
{
        return test_bit(BTNXPUART_IR_IN_PROGRESS, &nxpdev->tx_state);
}

static bool fw_dump_in_progress(struct btnxpuart_dev *nxpdev)
{
        return test_bit(BTNXPUART_FW_DUMP_IN_PROGRESS, &nxpdev->tx_state);
}

static bool process_boot_signature(struct btnxpuart_dev *nxpdev)
{
        if (test_bit(BTNXPUART_CHECK_BOOT_SIGNATURE, &nxpdev->tx_state)) {
                clear_bit(BTNXPUART_CHECK_BOOT_SIGNATURE, &nxpdev->tx_state);
                wake_up_interruptible(&nxpdev->check_boot_sign_wait_q);
                return false;
        }
        return is_fw_downloading(nxpdev);
}

static int nxp_request_firmware(struct hci_dev *hdev, const char *fw_name,
                                const char *fw_name_old)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        const char *fw_name_dt;
        int err = 0;

        if (!fw_name)
                return -ENOENT;

        if (!strlen(nxpdev->fw_name)) {
                if (strcmp(fw_name, FIRMWARE_HELPER) &&
                    !device_property_read_string(&nxpdev->serdev->dev,
                                                 "firmware-name",
                                                 &fw_name_dt))
                        fw_name = fw_name_dt;
                snprintf(nxpdev->fw_name, MAX_FW_FILE_NAME_LEN, "nxp/%s", fw_name);
                err = request_firmware_direct(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
                if (err < 0 && fw_name_old) {
                        snprintf(nxpdev->fw_name, MAX_FW_FILE_NAME_LEN, "nxp/%s", fw_name_old);
                        err = request_firmware_direct(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
                }

                bt_dev_info(hdev, "Request Firmware: %s", nxpdev->fw_name);
                if (err < 0) {
                        bt_dev_err(hdev, "Firmware file %s not found", nxpdev->fw_name);
                        clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
                }
        }
        return err;
}

/* for legacy chipsets with V1 bootloader */
static int nxp_recv_chip_ver_v1(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct v1_start_ind *req;
        __u16 chip_id;

        req = skb_pull_data(skb, sizeof(*req));
        if (!req)
                goto free_skb;

        chip_id = le16_to_cpu(req->chip_id ^ req->chip_id_comp);
        if (chip_id == 0xffff && nxpdev->fw_dnld_v1_offset) {
                nxpdev->fw_dnld_v1_offset = 0;
                nxpdev->fw_v1_sent_bytes = 0;
                nxpdev->fw_v1_expected_len = HDR_LEN;
                release_firmware(nxpdev->fw);
                memset(nxpdev->fw_name, 0, sizeof(nxpdev->fw_name));
                nxp_send_ack(NXP_ACK_V1, hdev);
        }

free_skb:
        kfree_skb(skb);
        return 0;
}

static int nxp_recv_fw_req_v1(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
        struct v1_data_req *req;
        __u16 len;

        if (!process_boot_signature(nxpdev))
                goto free_skb;

        req = skb_pull_data(skb, sizeof(*req));
        if (!req)
                goto free_skb;

        len = __le16_to_cpu(req->len ^ req->len_comp);
        if (len != 0xffff) {
                bt_dev_dbg(hdev, "ERR: Send NAK");
                nxp_send_ack(NXP_NAK_V1, hdev);
                goto free_skb;
        }
        nxp_send_ack(NXP_ACK_V1, hdev);

        len = __le16_to_cpu(req->len);

        if (!nxp_data->helper_fw_name) {
                if (nxpdev->timeout_changed != changed) {
                        nxp_fw_change_timeout(hdev, len);
                        nxpdev->timeout_changed = changed;
                        goto free_skb;
                }
                if (nxpdev->baudrate_changed != changed) {
                        nxpdev->new_baudrate = nxpdev->secondary_baudrate;
                        if (nxp_fw_change_baudrate(hdev, len)) {
                                nxpdev->baudrate_changed = changed;
                                serdev_device_set_baudrate(nxpdev->serdev,
                                                           nxpdev->secondary_baudrate);
                                serdev_device_set_flow_control(nxpdev->serdev, true);
                                nxpdev->current_baudrate = nxpdev->secondary_baudrate;
                        }
                        goto free_skb;
                }
        }

        if (!nxp_data->helper_fw_name || nxpdev->helper_downloaded) {
                if (nxp_request_firmware(hdev, nxp_data->fw_name, nxp_data->fw_name_old))
                        goto free_skb;
        } else if (nxp_data->helper_fw_name && !nxpdev->helper_downloaded) {
                if (nxp_request_firmware(hdev, nxp_data->helper_fw_name, NULL))
                        goto free_skb;
        }

        if (!len) {
                bt_dev_info(hdev, "FW Download Complete: %zu bytes",
                           nxpdev->fw->size);
                if (nxp_data->helper_fw_name && !nxpdev->helper_downloaded) {
                        nxpdev->helper_downloaded = true;
                        serdev_device_wait_until_sent(nxpdev->serdev, 0);
                        serdev_device_set_baudrate(nxpdev->serdev,
                                                   HCI_NXP_SEC_BAUDRATE_3M);
                        serdev_device_set_flow_control(nxpdev->serdev, true);
                } else {
                        clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
                        wake_up_interruptible(&nxpdev->fw_dnld_done_wait_q);
                }
                goto free_skb;
        }
        if (len & 0x01) {
                /* The CRC did not match at the other end.
                 * Simply send the same bytes again.
                 */
                len = nxpdev->fw_v1_sent_bytes;
                bt_dev_dbg(hdev, "CRC error. Resend %d bytes of FW.", len);
        } else {
                nxpdev->fw_dnld_v1_offset += nxpdev->fw_v1_sent_bytes;

                /* The FW bin file is made up of many blocks of
                 * 16 byte header and payload data chunks. If the
                 * FW has requested a header, read the payload length
                 * info from the header, before sending the header.
                 * In the next iteration, the FW should request the
                 * payload data chunk, which should be equal to the
                 * payload length read from header. If there is a
                 * mismatch, clearly the driver and FW are out of sync,
                 * and we need to re-send the previous header again.
                 */
                if (len == nxpdev->fw_v1_expected_len) {
                        if (len == HDR_LEN)
                                nxpdev->fw_v1_expected_len = nxp_get_data_len(nxpdev->fw->data +
                                                                        nxpdev->fw_dnld_v1_offset);
                        else
                                nxpdev->fw_v1_expected_len = HDR_LEN;
                } else if (len == HDR_LEN) {
                        /* FW download out of sync. Send previous chunk again */
                        nxpdev->fw_dnld_v1_offset -= nxpdev->fw_v1_sent_bytes;
                        nxpdev->fw_v1_expected_len = HDR_LEN;
                }
        }

        if (nxpdev->fw_dnld_v1_offset + len <= nxpdev->fw->size)
                serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data +
                                        nxpdev->fw_dnld_v1_offset, len);
        nxpdev->fw_v1_sent_bytes = len;

free_skb:
        kfree_skb(skb);
        return 0;
}

static char *nxp_get_fw_name_from_chipid(struct hci_dev *hdev, u16 chipid,
                                         u8 loader_ver)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        char *fw_name = NULL;

        switch (chipid) {
        case CHIP_ID_W9098:
                fw_name = FIRMWARE_W9098;
                break;
        case CHIP_ID_IW416:
                fw_name = FIRMWARE_IW416;
                break;
        case CHIP_ID_IW612:
                fw_name = FIRMWARE_IW612;
                break;
        case CHIP_ID_IW624a:
        case CHIP_ID_IW624c:
                nxpdev->boot_reg_offset = 1;
                if ((loader_ver & FW_SECURE_MASK) == FW_OPEN)
                        fw_name = FIRMWARE_IW624;
                else if ((loader_ver & FW_SECURE_MASK) != FW_AUTH_ILLEGAL)
                        fw_name = FIRMWARE_SECURE_IW624;
                else
                        bt_dev_err(hdev, "Illegal loader version %02x", loader_ver);
                break;
        case CHIP_ID_AW693a0:
                if ((loader_ver & FW_SECURE_MASK) == FW_OPEN)
                        fw_name = FIRMWARE_AW693;
                else if ((loader_ver & FW_SECURE_MASK) != FW_AUTH_ILLEGAL)
                        fw_name = FIRMWARE_SECURE_AW693;
                else
                        bt_dev_err(hdev, "Illegal loader version %02x", loader_ver);
                break;
        case CHIP_ID_AW693a1:
                if ((loader_ver & FW_SECURE_MASK) == FW_OPEN)
                        fw_name = FIRMWARE_AW693_A1;
                else if ((loader_ver & FW_SECURE_MASK) != FW_AUTH_ILLEGAL)
                        fw_name = FIRMWARE_SECURE_AW693_A1;
                else
                        bt_dev_err(hdev, "Illegal loader version %02x", loader_ver);
                break;
        case CHIP_ID_IW610a0:
        case CHIP_ID_IW610a1:
                if ((loader_ver & FW_SECURE_MASK) == FW_OPEN)
                        fw_name = FIRMWARE_IW610;
                else if ((loader_ver & FW_SECURE_MASK) != FW_AUTH_ILLEGAL)
                        fw_name = FIRMWARE_SECURE_IW610;
                else
                        bt_dev_err(hdev, "Illegal loader version %02x", loader_ver);
                break;
        default:
                bt_dev_err(hdev, "Unknown chip signature %04x", chipid);
                break;
        }
        return fw_name;
}

static char *nxp_get_old_fw_name_from_chipid(struct hci_dev *hdev, u16 chipid,
                                         u8 loader_ver)
{
        char *fw_name_old = NULL;

        switch (chipid) {
        case CHIP_ID_W9098:
                fw_name_old = FIRMWARE_W9098_OLD;
                break;
        case CHIP_ID_IW416:
                fw_name_old = FIRMWARE_IW416_OLD;
                break;
        }
        return fw_name_old;
}

static int nxp_recv_chip_ver_v3(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct v3_start_ind *req = skb_pull_data(skb, sizeof(*req));
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        const char *fw_name;
        const char *fw_name_old;
        u16 chip_id;
        u8 loader_ver;

        if (!process_boot_signature(nxpdev))
                goto free_skb;

        chip_id = le16_to_cpu(req->chip_id);
        loader_ver = req->loader_ver;
        bt_dev_info(hdev, "ChipID: %04x, Version: %d", chip_id, loader_ver);
        fw_name = nxp_get_fw_name_from_chipid(hdev, chip_id, loader_ver);
        fw_name_old = nxp_get_old_fw_name_from_chipid(hdev, chip_id, loader_ver);
        if (!nxp_request_firmware(hdev, fw_name, fw_name_old))
                nxp_send_ack(NXP_ACK_V3, hdev);

free_skb:
        kfree_skb(skb);
        return 0;
}

static void nxp_handle_fw_download_error(struct hci_dev *hdev, struct v3_data_req *req)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        __u32 offset = __le32_to_cpu(req->offset);
        __u16 err = __le16_to_cpu(req->error);
        union nxp_v3_rx_timeout_nak_u timeout_nak_buf;
        union nxp_v3_crc_nak_u crc_nak_buf;

        if (err & NXP_CRC_RX_ERROR) {
                crc_nak_buf.pkt.nak = NXP_CRC_ERROR_V3;
                crc_nak_buf.pkt.crc = crc8(crc8_table, crc_nak_buf.buf,
                                           sizeof(crc_nak_buf) - 1, 0xff);
                serdev_device_write_buf(nxpdev->serdev, crc_nak_buf.buf,
                                        sizeof(crc_nak_buf));
        } else if (err & NXP_ACK_RX_TIMEOUT ||
                   err & NXP_HDR_RX_TIMEOUT ||
                   err & NXP_DATA_RX_TIMEOUT) {
                timeout_nak_buf.pkt.nak = NXP_NAK_V3;
                timeout_nak_buf.pkt.offset = __cpu_to_le32(offset);
                timeout_nak_buf.pkt.crc = crc8(crc8_table, timeout_nak_buf.buf,
                                               sizeof(timeout_nak_buf) - 1, 0xff);
                serdev_device_write_buf(nxpdev->serdev, timeout_nak_buf.buf,
                                        sizeof(timeout_nak_buf));
        } else {
                bt_dev_err(hdev, "Unknown bootloader error code: %d", err);
        }
}

static int nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct v3_data_req *req;
        __u16 len = 0;
        __u16 err = 0;
        __u32 offset;

        if (!process_boot_signature(nxpdev))
                goto free_skb;

        req = skb_pull_data(skb, sizeof(*req));
        if (!req || !nxpdev->fw)
                goto free_skb;

        err = __le16_to_cpu(req->error);

        if (!err) {
                nxp_send_ack(NXP_ACK_V3, hdev);
                if (nxpdev->timeout_changed == cmd_sent)
                        nxpdev->timeout_changed = changed;
                if (nxpdev->baudrate_changed == cmd_sent)
                        nxpdev->baudrate_changed = changed;
        } else {
                nxp_handle_fw_download_error(hdev, req);
                if (nxpdev->timeout_changed == cmd_sent &&
                    err == NXP_CRC_RX_ERROR) {
                        nxpdev->fw_v3_offset_correction -= nxpdev->fw_v3_prev_sent;
                        nxpdev->timeout_changed = not_changed;
                }
                if (nxpdev->baudrate_changed == cmd_sent &&
                    err == NXP_CRC_RX_ERROR) {
                        nxpdev->fw_v3_offset_correction -= nxpdev->fw_v3_prev_sent;
                        nxpdev->baudrate_changed = not_changed;
                }
                goto free_skb;
        }

        len = __le16_to_cpu(req->len);

        if (nxpdev->timeout_changed != changed) {
                nxp_fw_change_timeout(hdev, len);
                nxpdev->timeout_changed = cmd_sent;
                goto free_skb;
        }

        if (nxpdev->baudrate_changed != changed) {
                nxpdev->new_baudrate = nxpdev->secondary_baudrate;
                if (nxp_fw_change_baudrate(hdev, len)) {
                        nxpdev->baudrate_changed = cmd_sent;
                        serdev_device_set_baudrate(nxpdev->serdev,
                                                   nxpdev->secondary_baudrate);
                        serdev_device_set_flow_control(nxpdev->serdev, true);
                        nxpdev->current_baudrate = nxpdev->secondary_baudrate;
                }
                goto free_skb;
        }

        if (req->len == 0) {
                bt_dev_info(hdev, "FW Download Complete: %zu bytes",
                           nxpdev->fw->size);
                clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
                wake_up_interruptible(&nxpdev->fw_dnld_done_wait_q);
                goto free_skb;
        }

        offset = __le32_to_cpu(req->offset);
        if (offset < nxpdev->fw_v3_offset_correction) {
                /* This scenario should ideally never occur. But if it ever does,
                 * FW is out of sync and needs a power cycle.
                 */
                bt_dev_err(hdev, "Something went wrong during FW download");
                bt_dev_err(hdev, "Please power cycle and try again");
                goto free_skb;
        }

        nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction;
        if (nxpdev->fw_dnld_v3_offset >= nxpdev->fw->size ||
            len > nxpdev->fw->size - nxpdev->fw_dnld_v3_offset) {
                bt_dev_err(hdev, "FW download out of bounds, ignoring request");
                len = 0;
                goto free_skb;
        }
        serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data +
                                nxpdev->fw_dnld_v3_offset, len);

free_skb:
        nxpdev->fw_v3_prev_sent = len;
        kfree_skb(skb);
        return 0;
}

static int nxp_set_baudrate_cmd(struct hci_dev *hdev, void *data)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        __le32 new_baudrate = __cpu_to_le32(nxpdev->new_baudrate);
        struct ps_data *psdata = &nxpdev->psdata;
        struct sk_buff *skb;
        u8 *status;

        if (!psdata)
                return 0;

        skb = nxp_drv_send_cmd(hdev, HCI_NXP_SET_OPER_SPEED, 4,
                               (u8 *)&new_baudrate, true);
        if (IS_ERR(skb)) {
                bt_dev_err(hdev, "Setting baudrate failed (%ld)", PTR_ERR(skb));
                return PTR_ERR(skb);
        }

        status = (u8 *)skb_pull_data(skb, 1);
        if (status) {
                if (*status == 0) {
                        serdev_device_set_baudrate(nxpdev->serdev, nxpdev->new_baudrate);
                        nxpdev->current_baudrate = nxpdev->new_baudrate;
                }
                bt_dev_dbg(hdev, "Set baudrate response: status=%d, baudrate=%d",
                           *status, nxpdev->new_baudrate);
        }
        kfree_skb(skb);

        return 0;
}

static int nxp_check_boot_sign(struct btnxpuart_dev *nxpdev)
{
        serdev_device_set_baudrate(nxpdev->serdev, HCI_NXP_PRI_BAUDRATE);
        if (ind_reset_in_progress(nxpdev))
                serdev_device_set_flow_control(nxpdev->serdev, false);
        else
                serdev_device_set_flow_control(nxpdev->serdev, true);
        set_bit(BTNXPUART_CHECK_BOOT_SIGNATURE, &nxpdev->tx_state);

        return wait_event_interruptible_timeout(nxpdev->check_boot_sign_wait_q,
                                               !test_bit(BTNXPUART_CHECK_BOOT_SIGNATURE,
                                                         &nxpdev->tx_state),
                                               msecs_to_jiffies(1000));
}

static int nxp_set_ind_reset(struct hci_dev *hdev, void *data)
{
        static const u8 ir_hw_err[] = { HCI_EV_HARDWARE_ERROR,
                                        0x01, BTNXPUART_IR_HW_ERR };
        struct sk_buff *skb;

        skb = bt_skb_alloc(3, GFP_ATOMIC);
        if (!skb)
                return -ENOMEM;

        hci_skb_pkt_type(skb) = HCI_EVENT_PKT;
        skb_put_data(skb, ir_hw_err, 3);

        /* Inject Hardware Error to upper stack */
        return hci_recv_frame(hdev, skb);
}

/* Firmware dump */
static void nxp_coredump(struct hci_dev *hdev)
{
        struct sk_buff *skb;
        u8 pcmd = 2;

        skb = nxp_drv_send_cmd(hdev, HCI_NXP_TRIGGER_DUMP, 1, &pcmd, true);
        if (IS_ERR(skb))
                bt_dev_err(hdev, "Failed to trigger FW Dump. (%ld)", PTR_ERR(skb));
        else
                kfree_skb(skb);
}

static void nxp_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
{
        /* Nothing to be added in FW dump header */
}

static int nxp_process_fw_dump(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_acl_hdr *acl_hdr = (struct hci_acl_hdr *)skb_pull_data(skb,
                                                                          sizeof(*acl_hdr));
        struct nxp_fw_dump_hdr *fw_dump_hdr = (struct nxp_fw_dump_hdr *)skb->data;
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        __u16 seq_num = __le16_to_cpu(fw_dump_hdr->seq_num);
        __u16 buf_len = __le16_to_cpu(fw_dump_hdr->buf_len);
        int err;

        if (seq_num == 0x0001) {
                if (test_and_set_bit(BTNXPUART_FW_DUMP_IN_PROGRESS, &nxpdev->tx_state)) {
                        bt_dev_err(hdev, "FW dump already in progress");
                        goto free_skb;
                }
                bt_dev_warn(hdev, "==== Start FW dump ===");
                err = hci_devcd_init(hdev, NXP_FW_DUMP_SIZE);
                if (err < 0)
                        goto free_skb;

                schedule_delayed_work(&hdev->dump.dump_timeout,
                                      msecs_to_jiffies(20000));
        }

        err = hci_devcd_append(hdev, skb_clone(skb, GFP_ATOMIC));
        if (err < 0)
                goto free_skb;

        if (buf_len == 0) {
                bt_dev_warn(hdev, "==== FW dump complete ===");
                hci_devcd_complete(hdev);
                nxp_set_ind_reset(hdev, NULL);
        }

free_skb:
        kfree_skb(skb);
        return 0;
}

static int nxp_recv_acl_pkt(struct hci_dev *hdev, struct sk_buff *skb)
{
        __u16 handle = __le16_to_cpu(hci_acl_hdr(skb)->handle);

        /* FW dump chunks are ACL packets with conn handle 0xfff */
        if ((handle & 0x0FFF) == 0xFFF)
                return nxp_process_fw_dump(hdev, skb);
        else
                return hci_recv_frame(hdev, skb);
}

static int nxp_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
{
        union nxp_set_bd_addr_payload pcmd;
        int err;

        pcmd.data.param_id = 0xfe;
        pcmd.data.param_len = 6;
        memcpy(pcmd.data.param, bdaddr, 6);

        /* BD address can be assigned only after first reset command. */
        err = __hci_cmd_sync_status(hdev, HCI_OP_RESET, 0, NULL,
                                    HCI_INIT_TIMEOUT);
        if (err) {
                bt_dev_err(hdev,
                           "Reset before setting local-bd-addr failed (%d)",
                           err);
                return err;
        }

        err = __hci_cmd_sync_status(hdev, HCI_NXP_SET_BD_ADDR, sizeof(pcmd),
                             pcmd.buf, HCI_CMD_TIMEOUT);
        if (err) {
                bt_dev_err(hdev, "Changing device address failed (%d)", err);
                return err;
        }

        return 0;
}

/* NXP protocol */
static int nxp_setup(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct serdev_device *serdev = nxpdev->serdev;
        char device_string[30];
        char event_string[50];
        char *envp[] = {device_string, event_string, NULL};
        int err = 0;

        if (nxp_check_boot_sign(nxpdev)) {
                bt_dev_dbg(hdev, "Need FW Download.");
                err = nxp_download_firmware(hdev);
                if (err < 0)
                        return err;
        } else {
                bt_dev_info(hdev, "FW already running.");
                clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
        }

        snprintf(device_string, 30, "BTNXPUART_DEV=%s", dev_name(&serdev->dev));
        snprintf(event_string, 50, "BTNXPUART_STATE=FW_READY");
        bt_dev_dbg(hdev, "==== Send uevent: %s:%s ===", device_string,
                   event_string);
        kobject_uevent_env(&serdev->dev.kobj, KOBJ_CHANGE, envp);

        serdev_device_set_baudrate(nxpdev->serdev, nxpdev->fw_init_baudrate);
        nxpdev->current_baudrate = nxpdev->fw_init_baudrate;

        ps_init(hdev);

        if (test_and_clear_bit(BTNXPUART_IR_IN_PROGRESS, &nxpdev->tx_state))
                hci_dev_clear_flag(hdev, HCI_SETUP);

        return 0;
}

static int nxp_post_init(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;

        if (nxpdev->current_baudrate != nxpdev->secondary_baudrate) {
                nxpdev->new_baudrate = nxpdev->secondary_baudrate;
                nxp_set_baudrate_cmd(hdev, NULL);
        }
        if (psdata->cur_h2c_wakeupmode != psdata->h2c_wakeupmode)
                send_wakeup_method_cmd(hdev, NULL);
        if (psdata->cur_psmode != psdata->target_ps_mode)
                send_ps_cmd(hdev, NULL);
        return 0;
}

static void nxp_hw_err(struct hci_dev *hdev, u8 code)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);

        switch (code) {
        case BTNXPUART_IR_HW_ERR:
                set_bit(BTNXPUART_IR_IN_PROGRESS, &nxpdev->tx_state);
                hci_dev_set_flag(hdev, HCI_SETUP);
                break;
        default:
                break;
        }
}

static int nxp_shutdown(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct sk_buff *skb;
        u8 pcmd = 0;

        if (ind_reset_in_progress(nxpdev)) {
                if (test_and_clear_bit(BTNXPUART_FW_DUMP_IN_PROGRESS,
                                       &nxpdev->tx_state))
                        skb = nxp_drv_send_cmd(hdev, HCI_NXP_IND_RESET, 1,
                                               &pcmd, false);
                else
                        skb = nxp_drv_send_cmd(hdev, HCI_NXP_IND_RESET, 1,
                                               &pcmd, true);
                serdev_device_set_flow_control(nxpdev->serdev, false);
                set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
                /* HCI_NXP_IND_RESET command may not returns any response */
                if (!IS_ERR(skb))
                        kfree_skb(skb);
        }

        return 0;
}

static bool nxp_wakeup(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;

        if (psdata->c2h_wakeupmode != BT_HOST_WAKEUP_METHOD_NONE)
                return true;

        return false;
}

static void nxp_reset(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);

        if (!ind_reset_in_progress(nxpdev) && !fw_dump_in_progress(nxpdev)) {
                bt_dev_dbg(hdev, "CMD Timeout detected. Resetting.");
                nxp_set_ind_reset(hdev, NULL);
        }
}

static int btnxpuart_queue_skb(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);

        /* Prepend skb with frame type */
        memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
        skb_queue_tail(&nxpdev->txq, skb);
        btnxpuart_tx_wakeup(nxpdev);
        return 0;
}

static int nxp_enqueue(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct ps_data *psdata = &nxpdev->psdata;
        struct hci_command_hdr *hdr;
        struct psmode_cmd_payload ps_parm;
        struct wakeup_cmd_payload wakeup_parm;
        __le32 baudrate_parm;

        if (fw_dump_in_progress(nxpdev))
                return -EBUSY;

        /* if vendor commands are received from user space (e.g. hcitool), update
         * driver flags accordingly and ask driver to re-send the command to FW.
         * In case the payload for any command does not match expected payload
         * length, let the firmware and user space program handle it, or throw
         * an error.
         */
        if (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT && !psdata->driver_sent_cmd) {
                hdr = (struct hci_command_hdr *)skb->data;
                if (hdr->plen != (skb->len - HCI_COMMAND_HDR_SIZE))
                        return btnxpuart_queue_skb(hdev, skb);

                switch (__le16_to_cpu(hdr->opcode)) {
                case HCI_NXP_AUTO_SLEEP_MODE:
                        if (hdr->plen == sizeof(ps_parm)) {
                                memcpy(&ps_parm, skb->data + HCI_COMMAND_HDR_SIZE, hdr->plen);
                                if (ps_parm.ps_cmd == BT_PS_ENABLE)
                                        psdata->target_ps_mode = PS_MODE_ENABLE;
                                else if (ps_parm.ps_cmd == BT_PS_DISABLE)
                                        psdata->target_ps_mode = PS_MODE_DISABLE;
                                psdata->c2h_ps_interval = __le16_to_cpu(ps_parm.c2h_ps_interval);
                                hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);
                                goto free_skb;
                        }
                        break;
                case HCI_NXP_WAKEUP_METHOD:
                        if (hdr->plen == sizeof(wakeup_parm)) {
                                memcpy(&wakeup_parm, skb->data + HCI_COMMAND_HDR_SIZE, hdr->plen);
                                psdata->c2h_wakeupmode = wakeup_parm.c2h_wakeupmode;
                                psdata->c2h_wakeup_gpio = wakeup_parm.c2h_wakeup_gpio;
                                psdata->h2c_wakeup_gpio = wakeup_parm.h2c_wakeup_gpio;
                                switch (wakeup_parm.h2c_wakeupmode) {
                                case BT_CTRL_WAKEUP_METHOD_GPIO:
                                        psdata->h2c_wakeupmode = WAKEUP_METHOD_GPIO;
                                        break;
                                case BT_CTRL_WAKEUP_METHOD_DSR:
                                        psdata->h2c_wakeupmode = WAKEUP_METHOD_DTR;
                                        break;
                                case BT_CTRL_WAKEUP_METHOD_BREAK:
                                default:
                                        psdata->h2c_wakeupmode = WAKEUP_METHOD_BREAK;
                                        break;
                                }
                                hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
                                goto free_skb;
                        }
                        break;
                case HCI_NXP_SET_OPER_SPEED:
                        if (hdr->plen == sizeof(baudrate_parm)) {
                                memcpy(&baudrate_parm, skb->data + HCI_COMMAND_HDR_SIZE, hdr->plen);
                                nxpdev->new_baudrate = __le32_to_cpu(baudrate_parm);
                                hci_cmd_sync_queue(hdev, nxp_set_baudrate_cmd, NULL, NULL);
                                goto free_skb;
                        }
                        break;
                case HCI_NXP_IND_RESET:
                        if (hdr->plen == 1) {
                                hci_cmd_sync_queue(hdev, nxp_set_ind_reset, NULL, NULL);
                                goto free_skb;
                        }
                        break;
                default:
                        break;
                }
        }

        return btnxpuart_queue_skb(hdev, skb);

free_skb:
        kfree_skb(skb);
        return 0;
}

static struct sk_buff *nxp_dequeue(void *data)
{
        struct btnxpuart_dev *nxpdev = (struct btnxpuart_dev *)data;

        ps_start_timer(nxpdev);
        return skb_dequeue(&nxpdev->txq);
}

/* btnxpuart based on serdev */
static void btnxpuart_tx_work(struct work_struct *work)
{
        struct btnxpuart_dev *nxpdev = container_of(work, struct btnxpuart_dev,
                                                   tx_work);
        struct serdev_device *serdev = nxpdev->serdev;
        struct hci_dev *hdev = nxpdev->hdev;
        struct sk_buff *skb;
        int len;

        if (ps_wakeup(nxpdev))
                return;

        while ((skb = nxp_dequeue(nxpdev))) {
                len = serdev_device_write_buf(serdev, skb->data, skb->len);
                hdev->stat.byte_tx += len;

                skb_pull(skb, len);
                if (skb->len > 0) {
                        skb_queue_head(&nxpdev->txq, skb);
                        continue;
                }

                switch (hci_skb_pkt_type(skb)) {
                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;
                }

                kfree_skb(skb);
        }
        clear_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state);
}

static int btnxpuart_open(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        int err = 0;

        err = serdev_device_open(nxpdev->serdev);
        if (err) {
                bt_dev_err(hdev, "Unable to open UART device %s",
                           dev_name(&nxpdev->serdev->dev));
        } else {
                set_bit(BTNXPUART_SERDEV_OPEN, &nxpdev->tx_state);
        }
        return err;
}

static int btnxpuart_close(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);

        serdev_device_close(nxpdev->serdev);
        skb_queue_purge(&nxpdev->txq);
        if (!IS_ERR_OR_NULL(nxpdev->rx_skb)) {
                kfree_skb(nxpdev->rx_skb);
                nxpdev->rx_skb = NULL;
        }
        clear_bit(BTNXPUART_SERDEV_OPEN, &nxpdev->tx_state);
        return 0;
}

static int btnxpuart_flush(struct hci_dev *hdev)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);

        /* Flush any pending characters */
        serdev_device_write_flush(nxpdev->serdev);
        skb_queue_purge(&nxpdev->txq);

        cancel_work_sync(&nxpdev->tx_work);

        if (!IS_ERR_OR_NULL(nxpdev->rx_skb)) {
                kfree_skb(nxpdev->rx_skb);
                nxpdev->rx_skb = NULL;
        }

        return 0;
}

static const struct h4_recv_pkt nxp_recv_pkts[] = {
        { H4_RECV_ACL,          .recv = nxp_recv_acl_pkt },
        { H4_RECV_SCO,          .recv = hci_recv_frame },
        { H4_RECV_EVENT,        .recv = hci_recv_frame },
        { H4_RECV_ISO,          .recv = hci_recv_frame },
        { NXP_RECV_CHIP_VER_V1, .recv = nxp_recv_chip_ver_v1 },
        { NXP_RECV_FW_REQ_V1,   .recv = nxp_recv_fw_req_v1 },
        { NXP_RECV_CHIP_VER_V3, .recv = nxp_recv_chip_ver_v3 },
        { NXP_RECV_FW_REQ_V3,   .recv = nxp_recv_fw_req_v3 },
};

static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
                                    const u8 *data, size_t count)
{
        struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);

        ps_start_timer(nxpdev);

        nxpdev->rx_skb = h4_recv_buf(&nxpdev->hu, nxpdev->rx_skb, data, count,
                                     nxp_recv_pkts, ARRAY_SIZE(nxp_recv_pkts));
        if (IS_ERR(nxpdev->rx_skb)) {
                int err = PTR_ERR(nxpdev->rx_skb);
                /* Safe to ignore out-of-sync bootloader signatures */
                if (!is_fw_downloading(nxpdev) &&
                    !ind_reset_in_progress(nxpdev))
                        bt_dev_err(nxpdev->hdev, "Frame reassembly failed (%d)", err);
                return count;
        }
        if (!is_fw_downloading(nxpdev) &&
            !ind_reset_in_progress(nxpdev))
                nxpdev->hdev->stat.byte_rx += count;
        return count;
}

static void btnxpuart_write_wakeup(struct serdev_device *serdev)
{
        serdev_device_write_wakeup(serdev);
}

static const struct serdev_device_ops btnxpuart_client_ops = {
        .receive_buf = btnxpuart_receive_buf,
        .write_wakeup = btnxpuart_write_wakeup,
};

static void nxp_coredump_notify(struct hci_dev *hdev, int state)
{
        struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
        struct serdev_device *serdev = nxpdev->serdev;
        char device_string[30];
        char event_string[50];
        char *envp[] = {device_string, event_string, NULL};

        snprintf(device_string, 30, "BTNXPUART_DEV=%s", dev_name(&serdev->dev));
        switch (state) {
        case HCI_DEVCOREDUMP_ACTIVE:
                snprintf(event_string, 50, "BTNXPUART_STATE=FW_DUMP_ACTIVE");
                break;
        case HCI_DEVCOREDUMP_DONE:
                snprintf(event_string, 50, "BTNXPUART_STATE=FW_DUMP_DONE");
                break;
        case HCI_DEVCOREDUMP_TIMEOUT:
                snprintf(event_string, 50, "BTNXPUART_STATE=FW_DUMP_TIMEOUT");
                break;
        default:
                snprintf(event_string, 50, "BTNXPUART_STATE=FW_DUMP_STATE_%d",
                         state);
                break;
        }
        bt_dev_dbg(hdev, "==== Send uevent: %s:%s ===", device_string,
                   event_string);
        kobject_uevent_env(&serdev->dev.kobj, KOBJ_CHANGE, envp);
}

static int nxp_serdev_probe(struct serdev_device *serdev)
{
        struct hci_dev *hdev;
        struct btnxpuart_dev *nxpdev;
        bdaddr_t ba = {0};
        int err;

        nxpdev = devm_kzalloc(&serdev->dev, sizeof(*nxpdev), GFP_KERNEL);
        if (!nxpdev)
                return -ENOMEM;

        nxpdev->nxp_data = (struct btnxpuart_data *)device_get_match_data(&serdev->dev);

        nxpdev->serdev = serdev;
        serdev_device_set_drvdata(serdev, nxpdev);

        serdev_device_set_client_ops(serdev, &btnxpuart_client_ops);

        INIT_WORK(&nxpdev->tx_work, btnxpuart_tx_work);
        skb_queue_head_init(&nxpdev->txq);

        init_waitqueue_head(&nxpdev->fw_dnld_done_wait_q);
        init_waitqueue_head(&nxpdev->check_boot_sign_wait_q);

        device_property_read_u32(&nxpdev->serdev->dev, "fw-init-baudrate",
                                 &nxpdev->fw_init_baudrate);
        if (!nxpdev->fw_init_baudrate)
                nxpdev->fw_init_baudrate = FW_INIT_BAUDRATE;

        device_property_read_u32(&nxpdev->serdev->dev, "max-speed",
                                 &nxpdev->secondary_baudrate);
        if (!nxpdev->secondary_baudrate ||
            (nxpdev->secondary_baudrate != HCI_NXP_SEC_BAUDRATE_3M &&
             nxpdev->secondary_baudrate != HCI_NXP_SEC_BAUDRATE_4M)) {
                if (nxpdev->secondary_baudrate)
                        dev_err(&serdev->dev,
                                "Invalid max-speed. Using default 3000000.");
                nxpdev->secondary_baudrate = HCI_NXP_SEC_BAUDRATE_3M;
        }

        set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);

        crc8_populate_msb(crc8_table, POLYNOMIAL8);

        nxpdev->pdn = devm_reset_control_get_optional_shared(&serdev->dev, NULL);
        if (IS_ERR(nxpdev->pdn))
                return PTR_ERR(nxpdev->pdn);

        err = devm_regulator_get_enable(&serdev->dev, "vcc");
        if (err) {
                dev_err(&serdev->dev, "Failed to enable vcc regulator\n");
                return err;
        }

        /* Initialize and register HCI device */
        hdev = hci_alloc_dev();
        if (!hdev) {
                dev_err(&serdev->dev, "Can't allocate HCI device\n");
                return -ENOMEM;
        }

        reset_control_deassert(nxpdev->pdn);

        nxpdev->hdev = hdev;
        nxpdev->hu.hdev = hdev;

        hdev->bus = HCI_UART;
        hci_set_drvdata(hdev, nxpdev);

        hdev->manufacturer = MANUFACTURER_NXP;
        hdev->open  = btnxpuart_open;
        hdev->close = btnxpuart_close;
        hdev->flush = btnxpuart_flush;
        hdev->setup = nxp_setup;
        hdev->post_init = nxp_post_init;
        hdev->send  = nxp_enqueue;
        hdev->hw_error = nxp_hw_err;
        hdev->shutdown = nxp_shutdown;
        hdev->wakeup = nxp_wakeup;
        hdev->reset = nxp_reset;
        hdev->set_bdaddr = nxp_set_bdaddr;
        SET_HCIDEV_DEV(hdev, &serdev->dev);

        device_property_read_u8_array(&nxpdev->serdev->dev,
                                      "local-bd-address",
                                      (u8 *)&ba, sizeof(ba));
        if (bacmp(&ba, BDADDR_ANY))
                hci_set_quirk(hdev, HCI_QUIRK_USE_BDADDR_PROPERTY);

        if (hci_register_dev(hdev) < 0) {
                dev_err(&serdev->dev, "Can't register HCI device\n");
                goto probe_fail;
        }

        if (ps_setup(hdev))
                goto probe_fail;

        hci_devcd_register(hdev, nxp_coredump, nxp_coredump_hdr,
                           nxp_coredump_notify);

        return 0;

probe_fail:
        reset_control_assert(nxpdev->pdn);
        hci_free_dev(hdev);
        return -ENODEV;
}

static void nxp_serdev_remove(struct serdev_device *serdev)
{
        struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
        struct hci_dev *hdev = nxpdev->hdev;

        if (is_fw_downloading(nxpdev)) {
                set_bit(BTNXPUART_FW_DOWNLOAD_ABORT, &nxpdev->tx_state);
                clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
                wake_up_interruptible(&nxpdev->check_boot_sign_wait_q);
                wake_up_interruptible(&nxpdev->fw_dnld_done_wait_q);
        } else {
                /* Restore FW baudrate to fw_init_baudrate if changed.
                 * This will ensure FW baudrate is in sync with
                 * driver baudrate in case this driver is re-inserted.
                 */
                if (nxpdev->current_baudrate != nxpdev->fw_init_baudrate) {
                        nxpdev->new_baudrate = nxpdev->fw_init_baudrate;
                        nxp_set_baudrate_cmd(hdev, NULL);
                }
        }

        ps_cleanup(nxpdev);
        hci_unregister_dev(hdev);
        reset_control_assert(nxpdev->pdn);
        hci_free_dev(hdev);
}

static int __maybe_unused nxp_serdev_suspend(struct device *dev)
{
        struct btnxpuart_dev *nxpdev = dev_get_drvdata(dev);
        struct ps_data *psdata = &nxpdev->psdata;

        ps_control(psdata->hdev, PS_STATE_SLEEP);

        if (psdata->wakeup_source) {
                enable_irq_wake(psdata->irq_handler);
                enable_irq(psdata->irq_handler);
        }
        return 0;
}

static int __maybe_unused nxp_serdev_resume(struct device *dev)
{
        struct btnxpuart_dev *nxpdev = dev_get_drvdata(dev);
        struct ps_data *psdata = &nxpdev->psdata;

        if (psdata->wakeup_source) {
                disable_irq(psdata->irq_handler);
                disable_irq_wake(psdata->irq_handler);
        }

        ps_control(psdata->hdev, PS_STATE_AWAKE);
        return 0;
}

#ifdef CONFIG_DEV_COREDUMP
static void nxp_serdev_coredump(struct device *dev)
{
        struct btnxpuart_dev *nxpdev = dev_get_drvdata(dev);
        struct hci_dev  *hdev = nxpdev->hdev;

        if (hdev->dump.coredump)
                hdev->dump.coredump(hdev);
}
#endif

static struct btnxpuart_data w8987_data __maybe_unused = {
        .helper_fw_name = NULL,
        .fw_name = FIRMWARE_W8987,
        .fw_name_old = FIRMWARE_W8987_OLD,
};

static struct btnxpuart_data w8997_data __maybe_unused = {
        .helper_fw_name = FIRMWARE_HELPER,
        .fw_name = FIRMWARE_W8997,
        .fw_name_old = FIRMWARE_W8997_OLD,
};

static const struct of_device_id nxpuart_of_match_table[] __maybe_unused = {
        { .compatible = "nxp,88w8987-bt", .data = &w8987_data },
        { .compatible = "nxp,88w8997-bt", .data = &w8997_data },
        { }
};
MODULE_DEVICE_TABLE(of, nxpuart_of_match_table);

static const struct dev_pm_ops nxp_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(nxp_serdev_suspend, nxp_serdev_resume)
};

static struct serdev_device_driver nxp_serdev_driver = {
        .probe = nxp_serdev_probe,
        .remove = nxp_serdev_remove,
        .driver = {
                .name = "btnxpuart",
                .of_match_table = of_match_ptr(nxpuart_of_match_table),
                .pm = &nxp_pm_ops,
#ifdef CONFIG_DEV_COREDUMP
                .coredump = nxp_serdev_coredump,
#endif
        },
};

module_serdev_device_driver(nxp_serdev_driver);

MODULE_AUTHOR("Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>");
MODULE_DESCRIPTION("NXP Bluetooth Serial driver");
MODULE_LICENSE("GPL");