From:   Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
To:     davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, marcel@holtmann.org,
        johan.hedberg@gmail.com, luiz.dentz@gmail.com,
        gregkh@linuxfoundation.org, jirislaby@kernel.org,
        alok.a.tiwari@oracle.com, hdanton@sina.com,
        ilpo.jarvinen@linux.intel.com
Cc:     netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
        linux-serial@vger.kernel.org, amitkumar.karwar@nxp.com,
        rohit.fule@nxp.com, sherry.sun@nxp.com, neeraj.sanjaykale@nxp.com
Subject: [PATCH v2 3/3] Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets
Date:   Mon, 30 Jan 2023 23:35:04 +0530
Message-Id: <20230130180504.2029440-4-neeraj.sanjaykale@nxp.com>
In-Reply-To: <20230130180504.2029440-1-neeraj.sanjaykale@nxp.com>
References: <20230130180504.2029440-1-neeraj.sanjaykale@nxp.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?R0N6bTJ4L0UvOGNSSGVjQW9QSGZtVDhtRHU2a1ozQW5ZcVFGVHZjZnNuTGV1?=
 =?utf-8?B?N0Q2RFJMdnJ2ak5iQ2g1STFFQU9UV1dTYmxsS0tFYU1qSkFNbUVCQ1lQL3J2?=
 =?utf-8?B?L2lzVWNsOE1MajlOWnRZeG53REplK284bGpRL3RjK2xTSzlsM1J6UlBEUWdt?=
 =?utf-8?B?V0ZGQVZXTXRjbDA5bzNHd0dEdExlZTV1OFNsL0J5UkZtaUJkbGRLc1BQeXdo?=
 =?utf-8?B?MWdHaFg5OXBRQ0NKTlRLYS83M3pibGM5cDlWWnhObFJvUmRoNDlETXZwR01Z?=
 =?utf-8?B?VXE2alc4MzFBWi9FamZhcmd0RWwybnFNaWEybnFUWWY4N3NqMnR1YUJua0kv?=
 =?utf-8?B?dlAydUFDellnU2pHb3V2QTliZmNPbW9ISHFqdGZSMTZGZGZXYUtVQTU4M0Jl?=
 =?utf-8?B?Z0lkRVhGSzhUdU15eTNVTzFGK0xMWHBVMGFqMzg1c0l0c1FTeWsrL3Y5K1Nz?=
 =?utf-8?B?dy9CTzA3bG0rbndNVGp6R2w0SVJmSDUzYU1yVHVyL0prZE4rZWJESDNtMEpS?=
 =?utf-8?B?QTlSQU1oM1JpS0NXVzFlNGxmTUlHMFIwakxoSTdtQktackdxcm54cVIzTElQ?=
 =?utf-8?B?RE1Bck5HQmZiN3EyWUNWZ2xLbGRsRkE1VVl0amZlZlRFcE9OdkhOckJKRWI2?=
 =?utf-8?B?SjVuMk1xbGp0T2htK243YW1LY2lWZEtlVFdBMS93Tk5ra21kbjJ2dU1odU5L?=
 =?utf-8?B?enFYL1krWmt2bVQ4YWRQcElzV013RVBTMHRDdU1kM0dDUW83d3pxNjN4SFdK?=
 =?utf-8?B?VDJLTU54QnNKMDZQcFd6MUZVRTFOUDBML1MvR0dhNXhxV0s5U2ZveGxqdCtJ?=
 =?utf-8?B?d2o1MkRBMVlWTEV0TjRpWWlMaFpEUjhaenM0djR1NGk3YTFxSkVqYWxlQzE0?=
 =?utf-8?B?SGhQYmJHMzZKM0ZmUyt6dlIrUmd4NzJmbzV6alNBUXExbGErVkl0UkFIMzN2?=
 =?utf-8?B?RUk2OWRKS3J0YTVTVzk4eGdtaFcvbk51RVVoT0Zvb3ZHUVl0TmRyRVQ1WVZW?=
 =?utf-8?B?NWhwYTdSL0ZHZjkxY3YwdXFrTmhNRDZnZ0l4eW94WGk3WGF4R1oyZUlldG9a?=
 =?utf-8?B?aFpxc1BDQ2hReGlCeUsxbUZ4UVp5cHhUUWRQcldpeVcxYVQ5L3htbDg0Vk1W?=
 =?utf-8?B?QVVmN0Q1aktvMGIxS3ZheFJvREZuRS9vSWFEYUIyb1dPN0pWVU54cjlZbVVr?=
 =?utf-8?B?UGhueU00Z3A1Z09RYzlueDNaenR6ckVTYnVpTXdRQkVvRHhScldLY3kvN3VK?=
 =?utf-8?B?UEZuNENzL1NrZVRCWUwzK2FLZVJCSERNekdEdGczVE10a09tcVBSTENBZnVr?=
 =?utf-8?B?M0tBVmdIRzFJUVNQSmtpeS9rVndJK0RvYndxUzEzZnlQQ0FwR1h4UnlYWTFv?=
 =?utf-8?B?UkNSWjhXckhrUU92UWVPemtKYitUVnpHUVhzRGdGSGNQQnMzRUlUbWdlVVZa?=
 =?utf-8?B?b0R0djhOaHJiM3hJOVVWU1lFMHo5dHVlS20zUFltdGVtdDRKaDNxUjg0RGxa?=
 =?utf-8?B?QkVKOWZDdUJLajRsL0ZqNHU4eGdMQmdkNk9peWxNOTh5YVJ5cGtHMlJwclk1?=
 =?utf-8?B?Uk53bUhpSmVCSStEWHhUOUFzSmxQcXpVUjJRakh0UUh4aEE3d3BKU05Fb2pZ?=
 =?utf-8?B?cHRDWHFVeFc1RDV0QzJZQlZ2ZmxNai9GdW5JZldLZ0xoVVp4M3RPdEMvNm5C?=
 =?utf-8?B?amdCaVczLzE4M1paSjFCTnJxckVPWjRoZzB2cUNDNlpDdzk2cFRjWW4rVDJQ?=
 =?utf-8?B?NERhd09Gd2hDd0pDbThxSGRQa1ROVWJzNXZRSWIwL2RRWlZtL0FlVXRoZEl1?=
 =?utf-8?B?a0xEMlB4Zy9uR0oydDZpQUlsZnQyZjdLTkNHNXFvZXRDZ3MxYmtuNHRPa0hx?=
 =?utf-8?B?NU1kQ0xaZm05Y2pZRXRSTG9UZmlwOFFEMDhGUUJ0djlRRlVYNmZHa000VkZD?=
 =?utf-8?B?WXEwdnlOVlJqUGRuUHFXUzBZbThZTlNuNkpsQlA2QzFYMjg2OWJGMzFORC85?=
 =?utf-8?B?SkNUazJieU1RWVJBWGcxTm9seXIybmdSTG1pNDc3MnArTUhwN1d6a2lUSVN5?=
 =?utf-8?B?RHhuYWFQTnA1YlR5SkZQYUFOQTY4RE1WaGd6KzJNN3crTzZaUEIxMjdVd3VF?=
 =?utf-8?B?TEo4YUp3RXVDZ0tRd1dvaU1NV0hmWXFLVWkrOUV3ejN5RkRWa0Zmck9MNGpt?=
 =?utf-8?B?ZkE9PQ==?=
X-OriginatorOrg: nxp.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 4b98eae7-f865-4df9-ef62-08db02ecc48a
X-MS-Exchange-CrossTenant-AuthSource: AM9PR04MB8603.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jan 2023 18:06:53.9940
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: bJIzSWPpa2B3mrNE3L10rBUo51w5kXc6SOCO8ISFQr8Rr8XJ6zeB/N8ZeLVvK1G3O1HS9gV9DKr1XO9ZWTT5Tg86eEQGPEas363KDafjAAg=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB8PR04MB7129
Precedence: bulk
List-ID: <linux-bluetooth.vger.kernel.org>
X-Mailing-List: linux-bluetooth@vger.kernel.org

This adds a driver based on serdev driver for the NXP BT serial
protocol based on running H:4, which can enable the built-in
Bluetooth device inside a generic NXP BT chip.

This driver has Power Save feature that will put the chip into
sleep state whenever there is no activity for 2000ms, and will
be woken up when any activity is to be initiated.

This driver enables the power save feature by default by sending
the vendor specific commands to the chip during setup.

During setup, the driver is capable of validating correct chip
is attached to the host based on the compatibility parameter
from DT and chip's unique bootloader signature, and download
firmware.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
---
v2: Removed conf file support and added static data for each chip based
on compatibility devices mentioned in DT bindings. Handled potential
memory leaks and null pointer dereference issues, simplified FW download
feature, handled byte-order and few cosmetic changes. (Ilpo Järvinen,
Alok Tiwari, Hillf Danton)
---
 MAINTAINERS                   |    1 +
 drivers/bluetooth/Kconfig     |   11 +
 drivers/bluetooth/Makefile    |    1 +
 drivers/bluetooth/btnxpuart.c | 1145 +++++++++++++++++++++++++++++++++
 drivers/bluetooth/btnxpuart.h |  227 +++++++
 5 files changed, 1385 insertions(+)
 create mode 100644 drivers/bluetooth/btnxpuart.c
 create mode 100644 drivers/bluetooth/btnxpuart.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d465c1124699..1190e46e9b13 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22840,6 +22840,7 @@ M:	Amitkumar Karwar <amitkumar.karwar@nxp.com>
 M:	Neeraj Kale <neeraj.sanjaykale@nxp.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/net/bluetooth/nxp-bluetooth.yaml
+F:      drivers/bluetooth/btnxpuart*
 
 THE REST
 M:	Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 5a1a7bec3c42..773b40d34b7b 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -465,4 +465,15 @@ config BT_VIRTIO
 	  Say Y here to compile support for HCI over Virtio into the
 	  kernel or say M to compile as a module.
 
+config BT_NXPUART
+	tristate "NXP protocol support"
+	depends on SERIAL_DEV_BUS
+	help
+	  NXP is serial driver required for NXP Bluetooth
+	  devices with UART interface.
+
+	  Say Y here to compile support for NXP Bluetooth UART device into
+	  the kernel, or say M here to compile as a module.
+
+
 endmenu
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index e0b261f24fc9..7a5967e9ac48 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_BT_QCA)		+= btqca.o
 obj-$(CONFIG_BT_MTK)		+= btmtk.o
 
 obj-$(CONFIG_BT_VIRTIO)		+= virtio_bt.o
+obj-$(CONFIG_BT_NXPUART)	+= btnxpuart.o
 
 obj-$(CONFIG_BT_HCIUART_NOKIA)	+= hci_nokia.o
 
diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
new file mode 100644
index 000000000000..6e6bc5a70af2
--- /dev/null
+++ b/drivers/bluetooth/btnxpuart.c
@@ -0,0 +1,1145 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *  NXP Bluetooth driver
+ *  Copyright 2018-2023 NXP
+ *
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ */
+
+#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 <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "btnxpuart.h"
+#include "h4_recv.h"
+
+#define BTNXPUART_TX_STATE_ACTIVE	1
+#define BTNXPUART_TX_STATE_WAKEUP	2
+#define BTNXPUART_FW_DOWNLOADING	3
+
+static u8 crc8_table[CRC8_TABLE_SIZE];
+static unsigned long crc32_table[256];
+
+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;
+
+	psdata->driver_sent_cmd = true;	/* set flag to prevent re-sending command in nxp_enqueue */
+	skb = __hci_cmd_sync(hdev, opcode, plen, param, HCI_CMD_TIMEOUT);
+	psdata->driver_sent_cmd = false;
+
+	return skb;
+}
+
+/* NXP Power Save Feature */
+int wakeupmode = WAKEUP_METHOD_BREAK;
+int ps_mode = PS_MODE_ENABLE;
+
+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) {
+		psdata->timer_on = 1;
+		mod_timer(&psdata->ps_timer, jiffies + (psdata->interval * HZ) / 1000);
+	}
+}
+
+static void ps_cancel_timer(struct btnxpuart_dev *nxpdev)
+{
+	struct ps_data *psdata = nxpdev->psdata;
+
+	if (!psdata)
+		return;
+
+	flush_work(&psdata->work);
+	if (psdata->timer_on)
+		del_timer_sync(&psdata->ps_timer);
+	kfree(psdata);
+}
+
+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;
+
+	if (psdata->ps_state == ps_state)
+		return;
+
+	switch (psdata->cur_wakeupmode) {
+	case WAKEUP_METHOD_DTR:
+		if (ps_state == PS_STATE_AWAKE)
+			serdev_device_set_tiocm(nxpdev->serdev, TIOCM_DTR, 0);
+		else
+			serdev_device_set_tiocm(nxpdev->serdev, 0, TIOCM_DTR);
+		break;
+	case WAKEUP_METHOD_BREAK:
+	default:
+		BT_INFO("Set UART break: %s", ps_state == PS_STATE_AWAKE ? "off" : "on");
+		if (ps_state == PS_STATE_AWAKE)
+			serdev_device_break_ctl(nxpdev->serdev, 0);
+		else
+			serdev_device_break_ctl(nxpdev->serdev, -1);
+		break;
+	}
+	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);
+
+	data->timer_on = 0;
+	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 ps_data *psdata = kzalloc(sizeof(*psdata), GFP_KERNEL);
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+
+	if (!psdata) {
+		BT_ERR("Can't allocate control structure for Power Save feature");
+		return -ENOMEM;
+	}
+	nxpdev->psdata = psdata;
+
+	psdata->interval = PS_DEFAULT_TIMEOUT_PERIOD;
+	psdata->ps_state = PS_STATE_AWAKE;
+	psdata->ps_mode = ps_mode;
+	psdata->hdev = hdev;
+
+	switch (wakeupmode) {
+	case WAKEUP_METHOD_DTR:
+		psdata->wakeupmode = WAKEUP_METHOD_DTR;
+		break;
+	case WAKEUP_METHOD_BREAK:
+	default:
+		psdata->wakeupmode = WAKEUP_METHOD_BREAK;
+		break;
+	}
+
+	psdata->cur_psmode = PS_MODE_DISABLE;
+	psdata->cur_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;
+
+	psdata->timer_on = 0;
+	timer_setup(&psdata->ps_timer, ps_timeout_func, 0);
+}
+
+static int ps_wakeup(struct btnxpuart_dev *nxpdev)
+{
+	struct ps_data *psdata = nxpdev->psdata;
+	int ret = 1;
+
+	if (psdata->ps_state == PS_STATE_AWAKE)
+		ret = 0;
+	psdata->ps_cmd = PS_CMD_EXIT_PS;
+	schedule_work(&psdata->work);
+
+	return ret;
+}
+
+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;
+	u8 pcmd;
+	struct sk_buff *skb;
+	u8 *status;
+
+	if (psdata->ps_mode == PS_MODE_ENABLE)
+		pcmd = BT_PS_ENABLE;
+	else
+		pcmd = BT_PS_DISABLE;
+
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_AUTO_SLEEP_MODE, 1, &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->ps_mode;
+		else
+			psdata->ps_mode = psdata->cur_psmode;
+		if (psdata->cur_psmode == PS_MODE_ENABLE)
+			ps_start_timer(nxpdev);
+		else
+			ps_wakeup(nxpdev);
+		BT_INFO("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;
+	u8 pcmd[4];
+	struct sk_buff *skb;
+	u8 *status;
+
+	pcmd[0] = BT_HOST_WAKEUP_METHOD_NONE;
+	pcmd[1] = BT_HOST_WAKEUP_DEFAULT_GPIO;
+	switch (psdata->wakeupmode) {
+	case WAKEUP_METHOD_DTR:
+		pcmd[2] = BT_CTRL_WAKEUP_METHOD_DSR;
+		break;
+	case WAKEUP_METHOD_BREAK:
+	default:
+		pcmd[2] = BT_CTRL_WAKEUP_METHOD_BREAK;
+		break;
+	}
+	pcmd[3] = 0xFF;
+
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_WAKEUP_METHOD, 4, 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_wakeupmode = psdata->wakeupmode;
+		else
+			psdata->wakeupmode = psdata->cur_wakeupmode;
+		BT_INFO("Set Wakeup Method response: status=%d, wakeupmode=%d",
+			*status, psdata->cur_wakeupmode);
+	}
+	kfree_skb(skb);
+
+	return 0;
+}
+
+static int 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, TIOCM_RTS, 0);
+
+	switch (psdata->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);
+		serdev_device_break_ctl(nxpdev->serdev, 0);
+		break;
+	}
+	if (!test_bit(HCI_RUNNING, &hdev->flags)) {
+		BT_ERR("HCI_RUNNING is not set");
+		return -EBUSY;
+	}
+	if (psdata->cur_wakeupmode != psdata->wakeupmode)
+		hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
+	if (psdata->cur_psmode != psdata->ps_mode)
+		hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);
+
+	return 0;
+}
+
+/* NXP Firmware Download Feature */
+static void nxp_fw_dnld_gen_crc_table(void)
+{
+	int i, j;
+	unsigned long crc_accum;
+
+	for (i = 0; i < 256; i++) {
+		crc_accum = ((unsigned long)i << 24);
+		for (j = 0; j < 8; j++) {
+			if (crc_accum & 0x80000000L)
+				crc_accum = (crc_accum << 1) ^ POLYNOMIAL32;
+			else
+				crc_accum = (crc_accum << 1);
+		}
+		crc32_table[i] = crc_accum;
+	}
+}
+
+static unsigned long nxp_fw_dnld_update_crc(unsigned long crc_accum,
+										char *data_blk_ptr,
+										int data_blk_size)
+{
+	unsigned long i, j;
+
+	for (j = 0; j < data_blk_size; j++) {
+		i = ((unsigned long)(crc_accum >> 24) ^ *data_blk_ptr++) & 0xff;
+		crc_accum = (crc_accum << 8) ^ crc32_table[i];
+	}
+	return crc_accum;
+}
+
+static int nxp_download_firmware(struct hci_dev *hdev)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+	const char *fw_name_dt;
+	int err = 0;
+
+	nxpdev->fw_dnld_offset = 0;
+	nxpdev->fw_sent_bytes = 0;
+
+	set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
+	crc8_populate_msb(crc8_table, POLYNOMIAL8);
+	nxp_fw_dnld_gen_crc_table();
+
+	if (!device_property_read_string(&nxpdev->serdev->dev, "firmware-name",
+										&fw_name_dt))
+		snprintf(nxpdev->fw_name, MAX_FW_FILE_NAME_LEN, "nxp/%s",
+					fw_name_dt);
+	else
+		snprintf(nxpdev->fw_name, MAX_FW_FILE_NAME_LEN, "%s",
+					nxp_data->fw_name);
+
+	BT_INFO("Request Firmware: %s", nxpdev->fw_name);
+	err = request_firmware(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
+	if (err < 0) {
+		BT_ERR("Firmware file %s not found", nxpdev->fw_name);
+		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
+	}
+
+	serdev_device_set_baudrate(nxpdev->serdev, nxp_data->fw_dnld_pri_baudrate);
+	serdev_device_set_flow_control(nxpdev->serdev, 0);
+	nxpdev->current_baudrate = nxp_data->fw_dnld_pri_baudrate;
+	nxpdev->fw_v3_offset_correction = 0;
+
+	/* Wait till FW is downloaded and CTS becomes low */
+	init_waitqueue_head(&nxpdev->suspend_wait_q);
+	err = wait_event_interruptible_timeout(nxpdev->suspend_wait_q,
+			!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state),
+			msecs_to_jiffies(60000));
+	if (err == 0) {
+		BT_ERR("FW Download Timeout.");
+		return -ETIMEDOUT;
+	}
+
+	err = serdev_device_wait_for_cts(nxpdev->serdev, 1, 60000);
+	if (err < 0) {
+		BT_ERR("CTS is still high. FW Download failed.");
+		return err;
+	}
+	BT_INFO("CTS is low");
+	release_firmware(nxpdev->fw);
+
+	/* Allow the downloaded FW to initialize */
+	usleep_range(20000, 22000);
+
+	return 0;
+}
+
+static int nxp_send_ack(u8 ack, struct hci_dev *hdev)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	u8 ack_nak[2];
+
+	if (ack == NXP_ACK_V1 || ack == NXP_NAK_V1) {
+		ack_nak[0] = ack;
+		serdev_device_write_buf(nxpdev->serdev, ack_nak, 1);
+	} else if (ack == NXP_ACK_V3) {
+		ack_nak[0] = ack;
+		ack_nak[1] = crc8(crc8_table, ack_nak, 1, 0xFF);
+		serdev_device_write_buf(nxpdev->serdev, ack_nak, 2);
+	}
+	return 0;
+}
+
+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));
+		nxp_cmd5.crc = swab32(nxp_fw_dnld_update_crc(0UL,
+									 (char *)&nxp_cmd5,
+									 sizeof(nxp_cmd5) - 4));
+
+		serdev_device_write_buf(nxpdev->serdev, (u8 *)&nxp_cmd5, req_len);
+		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);
+		uart_config.crc = swab32(nxp_fw_dnld_update_crc(0UL,
+										(char *)&uart_config,
+										sizeof(uart_config) - 4));
+		serdev_device_write_buf(nxpdev->serdev, (u8 *)&uart_config, req_len);
+		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)) {
+		nxp_cmd7.header = __cpu_to_le32(7);
+		nxp_cmd7.arg = __cpu_to_le32(0x70);
+		nxp_cmd7.payload_len = 0;
+		nxp_cmd7.crc = swab32(nxp_fw_dnld_update_crc(0UL,
+										(char *)&nxp_cmd7,
+										sizeof(nxp_cmd7) - 4));
+
+		serdev_device_write_buf(nxpdev->serdev, (u8 *)&nxp_cmd7, req_len);
+		serdev_device_wait_until_sent(nxpdev->serdev, 0);
+		nxpdev->fw_v3_offset_correction += req_len;
+		return true;
+	}
+	return false;
+}
+
+
+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);
+}
+
+/* for legacy chipsets with V1 bootloader */
+static int nxp_recv_fw_req_v1(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct v1_data_req *req = skb_pull_data(skb, sizeof(struct v1_data_req));
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+	static bool timeout_changed;
+	static bool baudrate_changed;
+	u32 requested_len;
+	static u32 expected_len = HDR_LEN;
+
+	if (!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state))
+		goto ret;
+
+	if (!nxpdev->fw)
+		goto ret;
+
+	if (req && (req->len ^ req->len_comp) != 0xffff) {
+		BT_INFO("ERR: Send NAK");
+		nxp_send_ack(NXP_NAK_V1, hdev);
+		goto ret;
+	}
+
+	if (nxp_data->fw_dnld_sec_baudrate != nxpdev->current_baudrate) {
+		if (!timeout_changed) {
+			nxp_send_ack(NXP_ACK_V1, hdev);
+			timeout_changed = nxp_fw_change_timeout(hdev, req->len);
+			goto ret;
+		}
+		if (!baudrate_changed) {
+			nxp_send_ack(NXP_ACK_V1, hdev);
+			baudrate_changed = nxp_fw_change_baudrate(hdev, req->len);
+			if (baudrate_changed) {
+				serdev_device_set_baudrate(nxpdev->serdev,
+								nxp_data->fw_dnld_sec_baudrate);
+				nxpdev->current_baudrate = nxp_data->fw_dnld_sec_baudrate;
+			}
+			goto ret;
+		}
+	}
+
+	nxp_send_ack(NXP_ACK_V1, hdev);
+	requested_len = req->len;
+	if (requested_len == 0) {
+		BT_INFO("FW Downloaded Successfully: %zu bytes", nxpdev->fw->size);
+		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
+		wake_up_interruptible(&nxpdev->suspend_wait_q);
+		goto ret;
+	}
+	if (requested_len & 0x01) {
+		/* The CRC did not match at the other end.
+		* That's why the request to re-send.
+		* Simply send the same bytes again.
+		*/
+		requested_len = nxpdev->fw_sent_bytes;
+		BT_ERR("CRC error. Resend %d bytes of FW.", requested_len);
+	} else {
+		/* 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 chunk again.
+		*/
+		if (requested_len == expected_len) {
+			/* All OK here. Increment offset by number
+			* of previous successfully sent bytes.
+			*/
+			nxpdev->fw_dnld_offset += nxpdev->fw_sent_bytes;
+
+			if (requested_len == HDR_LEN)
+				expected_len = nxp_get_data_len(nxpdev->fw->data +
+									nxpdev->fw_dnld_offset);
+			else
+				expected_len = HDR_LEN;
+		}
+	}
+
+	if (nxpdev->fw_dnld_offset + requested_len <= nxpdev->fw->size)
+		serdev_device_write_buf(nxpdev->serdev,
+				nxpdev->fw->data + nxpdev->fw_dnld_offset,
+				requested_len);
+	nxpdev->fw_sent_bytes = requested_len;
+
+ret:
+	kfree_skb(skb);
+	return 0;
+}
+
+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(struct v3_start_ind));
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+
+	if (!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state))
+		goto ret;
+
+	if (!req)
+		goto ret;
+
+	if (req->chip_id != nxp_data->chip_signature) {
+		BT_ERR("Invalid chip signature received");
+		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
+	} else {
+		nxp_send_ack(NXP_ACK_V3, hdev);
+	}
+
+ret:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct v3_data_req *req = skb_pull_data(skb, sizeof(struct v3_data_req));
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+	static bool timeout_changed;
+	static bool baudrate_changed;
+
+	if (!req || !nxpdev || !nxpdev->fw->data)
+		goto ret;
+
+	if (!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state))
+		goto ret;
+
+	nxp_send_ack(NXP_ACK_V3, hdev);
+
+	if (nxpdev->current_baudrate != nxp_data->fw_dnld_sec_baudrate) {
+		if (!timeout_changed) {
+			timeout_changed = nxp_fw_change_timeout(hdev, req->len);
+			goto ret;
+		}
+
+		if (!baudrate_changed) {
+			baudrate_changed = nxp_fw_change_baudrate(hdev, req->len);
+			if (baudrate_changed) {
+				serdev_device_set_baudrate(nxpdev->serdev,
+								nxp_data->fw_dnld_sec_baudrate);
+				nxpdev->current_baudrate = nxp_data->fw_dnld_sec_baudrate;
+			}
+			goto ret;
+		}
+	}
+
+	if (req->len == 0) {
+		BT_INFO("FW Downloaded Successfully: %zu bytes", nxpdev->fw->size);
+		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
+		wake_up_interruptible(&nxpdev->suspend_wait_q);
+		goto ret;
+	}
+	if (req->error)
+		BT_ERR("FW Download received err 0x%02X from chip. Resending FW chunk.",
+			   req->error);
+
+	if (req->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_ERR("Something went wrong during FW download. Please power cycle and try again");
+		goto ret;
+	}
+
+	serdev_device_write_buf(nxpdev->serdev,
+				nxpdev->fw->data + req->offset - nxpdev->fw_v3_offset_correction,
+				req->len);
+
+ret:
+	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);
+	u32 new_baudrate = __cpu_to_le32(nxpdev->new_baudrate);
+	struct ps_data *psdata = nxpdev->psdata;
+	u8 *pcmd = (u8 *)&new_baudrate;
+	struct sk_buff *skb;
+	u8 *status;
+
+	if (!psdata)
+		return -EFAULT;
+
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_SET_OPER_SPEED, 4, pcmd);
+
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Setting baudrate failed (%ld)", PTR_ERR(skb));
+		return PTR_ERR(skb);
+	}
+
+	status = 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_INFO("Set baudrate response: status=%d, baudrate=%d",
+			*status, nxpdev->new_baudrate);
+	}
+	kfree_skb(skb);
+
+	return 0;
+}
+
+/* NXP protocol */
+static int nxp_setup(struct hci_dev *hdev)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+	int ret = 0;
+
+	if (!serdev_device_get_cts(nxpdev->serdev)) {
+		BT_INFO("CTS high. Need FW Download");
+		ret = nxp_download_firmware(hdev);
+		if (ret < 0)
+			goto err;
+	} else {
+		BT_INFO("CTS low. FW already running.");
+	}
+
+	serdev_device_set_flow_control(nxpdev->serdev, 1);
+	serdev_device_set_baudrate(nxpdev->serdev, nxp_data->fw_init_baudrate);
+	nxpdev->current_baudrate = nxp_data->fw_init_baudrate;
+
+	if (nxpdev->current_baudrate != nxp_data->oper_speed) {
+		nxpdev->new_baudrate = nxp_data->oper_speed;
+		hci_cmd_sync_queue(hdev, nxp_set_baudrate_cmd, NULL, NULL);
+	}
+
+	if (!ps_init_work(hdev))
+		ps_init_timer(hdev);
+	ps_init(hdev);
+err:
+	return ret;
+}
+
+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;
+	u8 *param;
+
+	if (!psdata) {
+		kfree_skb(skb);
+		goto ret;
+	}
+
+	/* if commands are received from user space (e.g. hcitool), update
+	 * driver flags accordingly and ask driver to re-send the command
+	 */
+	if (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT && !psdata->driver_sent_cmd) {
+		hdr = (struct hci_command_hdr *)skb->data;
+		param = skb->data + HCI_COMMAND_HDR_SIZE;
+		switch (__le16_to_cpu(hdr->opcode)) {
+		case HCI_NXP_AUTO_SLEEP_MODE:
+			if (hdr->plen >= 1) {
+				if (param[0] == BT_PS_ENABLE)
+					psdata->ps_mode = PS_MODE_ENABLE;
+				else if (param[0] == BT_PS_DISABLE)
+					psdata->ps_mode = PS_MODE_DISABLE;
+				hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);
+				kfree_skb(skb);
+				goto ret;
+			}
+			break;
+		case HCI_NXP_WAKEUP_METHOD:
+			if (hdr->plen >= 4) {
+				switch (param[2]) {
+				case BT_CTRL_WAKEUP_METHOD_DSR:
+					psdata->wakeupmode = WAKEUP_METHOD_DTR;
+					break;
+				case BT_CTRL_WAKEUP_METHOD_BREAK:
+				default:
+					psdata->wakeupmode = WAKEUP_METHOD_BREAK;
+					break;
+				}
+				hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
+				kfree_skb(skb);
+				goto ret;
+			}
+			break;
+		case HCI_NXP_SET_OPER_SPEED:
+			if (hdr->plen == 4) {
+				nxpdev->new_baudrate = *((u32 *)param);
+				hci_cmd_sync_queue(hdev, nxp_set_baudrate_cmd, NULL, NULL);
+				kfree_skb(skb);
+				goto ret;
+			}
+		}
+	}
+
+	/* 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);
+ret:
+	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;
+
+	if (!nxpdev->nxp_data->dequeue)
+		return;
+
+	while (1) {
+		clear_bit(BTNXPUART_TX_STATE_WAKEUP, &nxpdev->tx_state);
+
+		while (1) {
+			struct sk_buff *skb = nxpdev->nxp_data->dequeue(nxpdev);
+			int len;
+
+			if (!skb)
+				break;
+
+			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);
+		}
+
+		if (!test_bit(BTNXPUART_TX_STATE_WAKEUP, &nxpdev->tx_state))
+			break;
+	}
+	clear_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state);
+}
+
+static void btnxpuart_tx_wakeup(struct btnxpuart_dev *nxpdev)
+{
+	if (test_and_set_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state)) {
+		set_bit(BTNXPUART_TX_STATE_WAKEUP, &nxpdev->tx_state);
+		return;
+	}
+	schedule_work(&nxpdev->tx_work);
+}
+
+static int btnxpuart_open(struct hci_dev *hdev)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	int err;
+
+	err = serdev_device_open(nxpdev->serdev);
+	if (err) {
+		bt_dev_err(hdev, "Unable to open UART device %s",
+			   dev_name(&nxpdev->serdev->dev));
+		return err;
+	}
+
+	if (nxpdev->nxp_data->open) {
+		err = nxpdev->nxp_data->open(hdev);
+		if (err) {
+			serdev_device_close(nxpdev->serdev);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int btnxpuart_close(struct hci_dev *hdev)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+	int err;
+
+	if (nxpdev->nxp_data->close) {
+		err = nxpdev->nxp_data->close(hdev);
+		if (err)
+			return err;
+	}
+
+	serdev_device_close(nxpdev->serdev);
+
+	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 int btnxpuart_setup(struct hci_dev *hdev)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+
+	if (nxpdev->nxp_data->setup)
+		return nxpdev->nxp_data->setup(hdev);
+
+	return 0;
+}
+
+static int btnxpuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
+
+	if (nxpdev->nxp_data->enqueue)
+		nxpdev->nxp_data->enqueue(hdev, skb);
+
+	return 0;
+}
+
+static int btnxpuart_receive_buf(struct serdev_device *serdev, const u8 *data,
+								 size_t count)
+{
+	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+
+	if (test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state)) {
+		if (*data != NXP_V1_FW_REQ_PKT && *data != NXP_V1_CHIP_VER_PKT &&
+		   *data != NXP_V3_FW_REQ_PKT && *data != NXP_V3_CHIP_VER_PKT) {
+			/* Unknown bootloader signature, skip without returning error */
+			return count;
+		}
+	}
+
+	ps_start_timer(nxpdev);
+
+	nxpdev->rx_skb = h4_recv_buf(nxpdev->hdev, nxpdev->rx_skb, data, count,
+						nxp_data->recv_pkts, nxp_data->recv_pkts_cnt);
+	if (IS_ERR(nxpdev->rx_skb)) {
+		int err = PTR_ERR(nxpdev->rx_skb);
+
+		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 = 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);
+
+	/* 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 = 37;
+	hdev->open  = btnxpuart_open;
+	hdev->close = btnxpuart_close;
+	hdev->flush = btnxpuart_flush;
+	hdev->setup = btnxpuart_setup;
+	hdev->send  = btnxpuart_send_frame;
+	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;
+	}
+
+	return 0;
+}
+
+static void nxp_serdev_remove(struct serdev_device *serdev)
+{
+	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
+	const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
+	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 (nxp_data->fw_init_baudrate != nxpdev->current_baudrate) {
+		nxpdev->new_baudrate = nxp_data->fw_init_baudrate;
+		nxp_set_baudrate_cmd(hdev, NULL);
+	}
+
+	ps_cancel_timer(nxpdev);
+	hci_unregister_dev(hdev);
+	hci_free_dev(hdev);
+}
+
+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_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 const struct btnxpuart_data w8987_data = {
+	.recv_pkts	= nxp_recv_pkts,
+	.recv_pkts_cnt	= ARRAY_SIZE(nxp_recv_pkts),
+	.fw_dnld_pri_baudrate = 115200,
+	.fw_dnld_sec_baudrate = 3000000,
+	.fw_init_baudrate = 115200,
+	.oper_speed		= 3000000,
+	.setup		= nxp_setup,
+	.enqueue    = nxp_enqueue,
+	.dequeue    = nxp_dequeue,
+	.chip_signature = 0xffff,
+	.fw_name = FIRMWARE_W8987,
+};
+
+static const struct btnxpuart_data w8997_data = {
+	.recv_pkts	= nxp_recv_pkts,
+	.recv_pkts_cnt	= ARRAY_SIZE(nxp_recv_pkts),
+	.fw_dnld_pri_baudrate = 115200,
+	.fw_dnld_sec_baudrate = 3000000,
+	.fw_init_baudrate = 115200,
+	.oper_speed		= 3000000,
+	.setup		= nxp_setup,
+	.enqueue    = nxp_enqueue,
+	.dequeue    = nxp_dequeue,
+	.chip_signature = 0xffff,
+	.fw_name = FIRMWARE_W8997,
+};
+
+static const struct btnxpuart_data w9098_data = {
+	.recv_pkts	= nxp_recv_pkts,
+	.recv_pkts_cnt	= ARRAY_SIZE(nxp_recv_pkts),
+	.fw_dnld_pri_baudrate = 115200,
+	.fw_dnld_sec_baudrate = 3000000,
+	.fw_init_baudrate = 3000000,
+	.oper_speed		= 3000000,
+	.setup		= nxp_setup,
+	.enqueue    = nxp_enqueue,
+	.dequeue    = nxp_dequeue,
+	.chip_signature = 0x5c03,
+	.fw_name = FIRMWARE_W9098,
+};
+
+static const struct btnxpuart_data iw416_data = {
+	.recv_pkts	= nxp_recv_pkts,
+	.recv_pkts_cnt	= ARRAY_SIZE(nxp_recv_pkts),
+	.fw_dnld_pri_baudrate = 115200,
+	.fw_dnld_sec_baudrate = 3000000,
+	.fw_init_baudrate = 3000000,
+	.oper_speed		= 3000000,
+	.setup		= nxp_setup,
+	.enqueue    = nxp_enqueue,
+	.dequeue    = nxp_dequeue,
+	.chip_signature = 0x7201,
+	.fw_name = FIRMWARE_IW416,
+};
+
+static const struct btnxpuart_data iw612_data = {
+	.recv_pkts	= nxp_recv_pkts,
+	.recv_pkts_cnt	= ARRAY_SIZE(nxp_recv_pkts),
+	.fw_dnld_pri_baudrate = 115200,
+	.fw_dnld_sec_baudrate = 3000000,
+	.fw_init_baudrate = 3000000,
+	.oper_speed		= 3000000,
+	.setup		= nxp_setup,
+	.enqueue    = nxp_enqueue,
+	.dequeue    = nxp_dequeue,
+	.chip_signature = 0x7601,
+	.fw_name = FIRMWARE_IW612,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id nxpuart_of_match_table[] = {
+	{ .compatible = "nxp,w8987-bt", .data = &w8987_data },
+	{ .compatible = "nxp,w8997-bt", .data = &w8997_data },
+	{ .compatible = "nxp,w9098-bt", .data = &w9098_data },
+	{ .compatible = "nxp,iw416-bt", .data = &iw416_data },
+	{ .compatible = "nxp,iw612-bt", .data = &iw612_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, nxpuart_of_match_table);
+#endif
+
+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 v1.0 ");
+MODULE_VERSION("v1.0");
+MODULE_LICENSE("GPL");
diff --git a/drivers/bluetooth/btnxpuart.h b/drivers/bluetooth/btnxpuart.h
new file mode 100644
index 000000000000..105204ef88f1
--- /dev/null
+++ b/drivers/bluetooth/btnxpuart.h
@@ -0,0 +1,227 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *
+ *  NXP Bluetooth driver
+ *  Copyright 2018-2023 NXP
+ *
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ */
+
+#ifndef BT_NXP_H_
+#define BT_NXP_H_
+
+#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/uartuart_iw416_bt.bin"
+#define FIRMWARE_IW612	"nxp/uartspi_n61x_v1.bin"
+
+#define MAX_CHIP_NAME_LEN       20
+#define MAX_FW_FILE_NAME_LEN    50
+#define MAX_NO_OF_CHIPS_SUPPORT 20
+
+/* Default ps timeout period in milli-second */
+#define PS_DEFAULT_TIMEOUT_PERIOD     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 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
+#define BT_HOST_WAKEUP_DEFAULT_GPIO     5
+
+/* 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
+#define BT_CTRL_WAKEUP_DEFAULT_GPIO     4
+
+struct ps_data {
+	u8    ps_mode;
+	u8    cur_psmode;
+	u8    ps_state;
+	u8    ps_cmd;
+	u8    wakeupmode;
+	u8    cur_wakeupmode;
+	bool  driver_sent_cmd;
+	u8    timer_on;
+	u32   interval;
+	struct hci_dev *hdev;
+	struct work_struct work;
+	struct timer_list ps_timer;
+};
+
+struct btnxpuart_data {
+	const struct h4_recv_pkt *recv_pkts;
+	int recv_pkts_cnt;
+	int (*open)(struct hci_dev *hdev);
+	int (*close)(struct hci_dev *hdev);
+	int (*setup)(struct hci_dev *hdev);
+	int (*enqueue)(struct hci_dev *hdev, struct sk_buff *skb);
+	struct sk_buff *(*dequeue)(void *data);
+	u32 fw_dnld_pri_baudrate;
+	u32 fw_dnld_sec_baudrate;
+	u32 fw_init_baudrate;
+	u32 oper_speed;
+	u16 chip_signature;
+	const u8 *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_offset;
+	u32 fw_sent_bytes;
+	u32 fw_v3_offset_correction;
+	wait_queue_head_t suspend_wait_q;
+
+	u32 new_baudrate;
+	u32 current_baudrate;
+
+	struct ps_data *psdata;
+	const 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_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 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
+#define POLYNOMIAL32			0x04c11db7L
+
+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;
+	__le32 crc;
+} __packed;
+
+struct nxp_bootloader_cmd {
+	__le32 header;
+	__le32 arg;
+	__le32 payload_len;
+	__le32 crc;
+} __packed;
+
+static void btnxpuart_tx_wakeup(struct btnxpuart_dev *nxpdev);
+
+#endif
-- 
2.34.1