linux/drivers/bluetooth/btnxpuart.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  NXP Bluetooth driver
 *  Copyright 2023 NXP
 */

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

#include <linux/serdev.h>
#include <linux/of.h>
#include <linux/skbuff.h>
#include <asm/unaligned.h>
#include <linux/firmware.h>
#include <linux/string.h>
#include <linux/crc8.h>
#include <linux/crc32.h>
#include <linux/string_helpers.h>

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

#include "h4_recv.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 FIRMWARE_W8987		"nxp/uartuart8987_bt.bin"
#define FIRMWARE_W8997		"nxp/uartuart8997_bt_v4.bin"
#define FIRMWARE_W9098		"nxp/uartuart9098_bt_v1.bin"
#define FIRMWARE_IW416		"nxp/uartiw416_bt_v0.bin"
#define FIRMWARE_IW612		"nxp/uartspi_n61x_v1.bin.se"
#define FIRMWARE_AW693		"nxp/uartaw693_bt.bin"
#define FIRMWARE_SECURE_AW693	"nxp/uartaw693_bt.bin.se"
#define FIRMWARE_HELPER		"nxp/helper_uart_3000000.bin"

#define CHIP_ID_W9098		0x5c03
#define CHIP_ID_IW416		0x7201
#define CHIP_ID_IW612		0x7601
#define CHIP_ID_AW693		0x8200

#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	3000000

#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_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

/* Bluetooth vendor command : Sleep mode */
#define HCI_NXP_AUTO_SLEEP_MODE	0xfc23
/* Bluetooth vendor command : Wakeup method */
#define HCI_NXP_WAKEUP_METHOD	0xfc53
/* Bluetooth vendor command : Set operational baudrate */
#define HCI_NXP_SET_OPER_SPEED	0xfc09
/* Bluetooth vendor command: Independent Reset */
#define HCI_NXP_IND_RESET	0xfcfc

/* 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;
	struct hci_dev *hdev;
	struct work_struct work;
	struct timer_list ps_timer;
};

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;
};

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_v3_offset_correction;
	u32 fw_v1_expected_len;
	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;
	bool timeout_changed;
	bool baudrate_changed;
	bool helper_downloaded;

	struct ps_data psdata;
	struct btnxpuart_data *nxp_data;
};

#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

#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;

static u8 crc8_table[CRC8_TABLE_SIZE];

/* Default configurations */
#define DEFAULT_H2C_WAKEUP_MODE	WAKEUP_METHOD_BREAK
#define DEFAULT_PS_MODE		PS_MODE_DISABLE
#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)
{
	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
	struct ps_data *psdata = &nxpdev->psdata;
	struct sk_buff *skb;

	/* set flag to prevent nxp_enqueue from parsing values from this command and
	 * calling hci_cmd_sync_queue() again.
	 */
	psdata->driver_sent_cmd = true;
	skb = __hci_cmd_sync(hdev, opcode, plen, param, HCI_CMD_TIMEOUT);
	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));
}

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

	flush_work(&psdata->work);
	del_timer_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;

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

	switch (psdata->cur_h2c_wakeupmode) {
	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);
		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;
	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 = from_timer(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 int ps_init_work(struct hci_dev *hdev)
{
	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
	struct ps_data *psdata = &nxpdev->psdata;

	psdata->h2c_ps_interval = PS_DEFAULT_TIMEOUT_PERIOD_MS;
	psdata->ps_state = PS_STATE_AWAKE;
	psdata->target_ps_mode = DEFAULT_PS_MODE;
	psdata->hdev = hdev;
	psdata->c2h_wakeupmode = BT_HOST_WAKEUP_METHOD_NONE;
	psdata->c2h_wakeup_gpio = 0xff;

	switch (DEFAULT_H2C_WAKEUP_MODE) {
	case WAKEUP_METHOD_DTR:
		psdata->h2c_wakeupmode = WAKEUP_METHOD_DTR;
		break;
	case WAKEUP_METHOD_BREAK:
	default:
		psdata->h2c_wakeupmode = WAKEUP_METHOD_BREAK;
		break;
	}
	psdata->cur_psmode = PS_MODE_DISABLE;
	psdata->cur_h2c_wakeupmode = WAKEUP_METHOD_INVALID;
	INIT_WORK(&psdata->work, ps_work_func);

	return 0;
}

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

	timer_setup(&psdata->ps_timer, ps_timeout_func, 0);
}

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

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

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);
	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;
	switch (psdata->h2c_wakeupmode) {
	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;
	}
	pcmd.h2c_wakeup_gpio = 0xff;

	skb = nxp_drv_send_cmd(hdev, HCI_NXP_WAKEUP_METHOD, sizeof(pcmd), &pcmd);
	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;

	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);

	switch (psdata->h2c_wakeupmode) {
	case 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:
		serdev_device_break_ctl(nxpdev->serdev, -1);
		usleep_range(5000, 10000);
		serdev_device_break_ctl(nxpdev->serdev, 0);
		usleep_range(5000, 10000);
		break;
	}
	if (psdata->cur_h2c_wakeupmode != psdata->h2c_wakeupmode)
		hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
	if (psdata->cur_psmode != psdata->target_ps_mode)
		hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);
}

/* 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->fw_v3_offset_correction = 0;
	nxpdev->baudrate_changed = false;
	nxpdev->timeout_changed = false;
	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 and CTS becomes low */
	err = wait_event_interruptible_timeout(nxpdev->fw_dnld_done_wait_q,
					       !test_bit(BTNXPUART_FW_DOWNLOADING,
							 &nxpdev->tx_state),
					       msecs_to_jiffies(60000));
	if (err == 0) {
		bt_dev_err(hdev, "FW Download Timeout.");
		return -ETIMEDOUT;
	}

	serdev_device_set_flow_control(nxpdev->serdev, true);
	release_firmware(nxpdev->fw);
	memset(nxpdev->fw_name, 0, sizeof(nxpdev->fw_name));

	/* 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;

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

	if (!fw_name)
		return -ENOENT;

	if (!strlen(nxpdev->fw_name)) {
		snprintf(nxpdev->fw_name, MAX_FW_FILE_NAME_LEN, "%s", fw_name);

		bt_dev_dbg(hdev, "Request Firmware: %s", nxpdev->fw_name);
		err = request_firmware(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
		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 = 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) {
			nxpdev->timeout_changed = nxp_fw_change_timeout(hdev,
									len);
			goto free_skb;
		}
		if (!nxpdev->baudrate_changed) {
			nxpdev->baudrate_changed = nxp_fw_change_baudrate(hdev,
									  len);
			if (nxpdev->baudrate_changed) {
				serdev_device_set_baudrate(nxpdev->serdev,
							   HCI_NXP_SEC_BAUDRATE);
				serdev_device_set_flow_control(nxpdev->serdev, true);
				nxpdev->current_baudrate = HCI_NXP_SEC_BAUDRATE;
			}
			goto free_skb;
		}
	}

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

	if (!len) {
		bt_dev_dbg(hdev, "FW Downloaded Successfully: %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);
			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)
{
	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_AW693:
		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;
	default:
		bt_dev_err(hdev, "Unknown chip signature %04x", chipid);
		break;
	}
	return fw_name;
}

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);
	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;
	if (!nxp_request_firmware(hdev, nxp_get_fw_name_from_chipid(hdev,
								    chip_id, loader_ver)))
		nxp_send_ack(NXP_ACK_V3, hdev);

free_skb:
	kfree_skb(skb);
	return 0;
}

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;
	__u32 offset;

	if (!process_boot_signature(nxpdev))
		goto free_skb;

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

	nxp_send_ack(NXP_ACK_V3, hdev);

	len = __le16_to_cpu(req->len);

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

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

	if (req->len == 0) {
		bt_dev_dbg(hdev, "FW Downloaded Successfully: %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;
	}
	if (req->error)
		bt_dev_dbg(hdev, "FW Download received err 0x%02x from chip",
			   req->error);

	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;
	}

	serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data + offset -
				nxpdev->fw_v3_offset_correction, len);

free_skb:
	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);
	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_set_ind_reset(struct hci_dev *hdev, void *data)
{
	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
	struct sk_buff *skb;
	u8 *status;
	u8 pcmd = 0;
	int err = 0;

	skb = nxp_drv_send_cmd(hdev, HCI_NXP_IND_RESET, 1, &pcmd);
	if (IS_ERR(skb))
		return PTR_ERR(skb);

	status = skb_pull_data(skb, 1);
	if (!status || *status)
		goto free_skb;

	set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
	err = nxp_download_firmware(hdev);
	if (err < 0)
		goto free_skb;
	serdev_device_set_baudrate(nxpdev->serdev, nxpdev->fw_init_baudrate);
	nxpdev->current_baudrate = nxpdev->fw_init_baudrate;
	if (nxpdev->current_baudrate != HCI_NXP_SEC_BAUDRATE) {
		nxpdev->new_baudrate = HCI_NXP_SEC_BAUDRATE;
		nxp_set_baudrate_cmd(hdev, NULL);
	}
	hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
	hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);

free_skb:
	kfree_skb(skb);
	return err;
}

/* NXP protocol */
static int nxp_check_boot_sign(struct btnxpuart_dev *nxpdev)
{
	serdev_device_set_baudrate(nxpdev->serdev, HCI_NXP_PRI_BAUDRATE);
	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_setup(struct hci_dev *hdev)
{
	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
	int err = 0;

	set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
	init_waitqueue_head(&nxpdev->fw_dnld_done_wait_q);
	init_waitqueue_head(&nxpdev->check_boot_sign_wait_q);

	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_dbg(hdev, "FW already running.");
		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
	}

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

	if (nxpdev->current_baudrate != HCI_NXP_SEC_BAUDRATE) {
		nxpdev->new_baudrate = HCI_NXP_SEC_BAUDRATE;
		hci_cmd_sync_queue(hdev, nxp_set_baudrate_cmd, NULL, NULL);
	}

	ps_init(hdev);

	return 0;
}

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 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_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_wakeup(nxpdev);
	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;

	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);
			break;
		}

		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);

	ps_wakeup(nxpdev);
	serdev_device_close(nxpdev->serdev);
	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);

	kfree_skb(nxpdev->rx_skb);
	nxpdev->rx_skb = NULL;

	return 0;
}

static const struct h4_recv_pkt nxp_recv_pkts[] = {
	{ H4_RECV_ACL,          .recv = hci_recv_frame },
	{ H4_RECV_SCO,          .recv = hci_recv_frame },
	{ H4_RECV_EVENT,        .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 int 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->hdev, 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))
			return count;
		bt_dev_err(nxpdev->hdev, "Frame reassembly failed (%d)", err);
		nxpdev->rx_skb = NULL;
		return err;
	}
	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 int nxp_serdev_probe(struct serdev_device *serdev)
{
	struct hci_dev *hdev;
	struct btnxpuart_dev *nxpdev;

	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);

	crc8_populate_msb(crc8_table, POLYNOMIAL8);

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

	nxpdev->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->send  = nxp_enqueue;
	SET_HCIDEV_DEV(hdev, &serdev->dev);

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

	ps_init_work(hdev);
	ps_init_timer(hdev);

	return 0;
}

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

	/* 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_cancel_timer(nxpdev);
	hci_unregister_dev(hdev);
	hci_free_dev(hdev);
}

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

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

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 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),
	},
};

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");