// SPDX-License-Identifier: (GPL-2.0-only OR MIT)
/*
 * Copyright (C) 2024 Amlogic, Inc. All rights reserved
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/property.h>
#include <linux/of.h>
#include <linux/serdev.h>
#include <linux/clk.h>
#include <linux/firmware.h>
#include <linux/gpio/consumer.h>
#include <linux/regulator/consumer.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/hci.h>

#include "hci_uart.h"

#define AML_EVT_HEAD_SIZE		4
#define AML_BDADDR_DEFAULT (&(bdaddr_t) {{ 0x00, 0xff, 0x00, 0x22, 0x2d, 0xae }})

#define AML_FIRMWARE_OPERATION_SIZE		(248)
#define AML_FIRMWARE_MAX_SIZE			(512 * 1024)

/* TCI command */
#define AML_TCI_CMD_READ			0xFEF0
#define AML_TCI_CMD_WRITE			0xFEF1
#define AML_TCI_CMD_UPDATE_BAUDRATE		0xFEF2
#define AML_TCI_CMD_HARDWARE_RESET		0xFEF2
#define AML_TCI_CMD_DOWNLOAD_BT_FW		0xFEF3

/* Vendor command */
#define AML_BT_HCI_VENDOR_CMD			0xFC1A

/* TCI operation parameter in controller chip */
#define AML_OP_UART_MODE			0x00A30128
#define AML_OP_EVT_ENABLE			0x00A70014
#define AML_OP_MEM_HARD_TRANS_EN		0x00A7000C
#define AML_OP_RF_CFG				0x00F03040
#define AML_OP_RAM_POWER_CTR			0x00F03050
#define AML_OP_HARDWARE_RST			0x00F03058
#define AML_OP_ICCM_RAM_BASE			0x00000000
#define AML_OP_DCCM_RAM_BASE			0x00D00000

/* UART configuration */
#define AML_UART_XMIT_EN			BIT(12)
#define AML_UART_RECV_EN			BIT(13)
#define AML_UART_TIMEOUT_INT_EN			BIT(14)
#define AML_UART_CLK_SOURCE			40000000

/* Controller event */
#define AML_EVT_EN				BIT(24)

/* RAM power control */
#define AML_RAM_POWER_ON			(0)
#define AML_RAM_POWER_OFF			(1)

/* RF configuration */
#define AML_RF_ANT_SINGLE			BIT(28)
#define AML_RF_ANT_DOUBLE			BIT(29)

/* Memory transaction */
#define AML_MM_CTR_HARD_TRAS_EN			BIT(27)

/* Controller reset */
#define AML_CTR_CPU_RESET			BIT(8)
#define AML_CTR_MAC_RESET			BIT(9)
#define AML_CTR_PHY_RESET			BIT(10)

enum {
	FW_ICCM,
	FW_DCCM
};

struct aml_fw_len {
	u32 iccm_len;
	u32 dccm_len;
};

struct aml_tci_rsp {
	u8 num_cmd_packet;
	u16 opcode;
	u8 status;
} __packed;

struct aml_device_data {
	int iccm_offset;
	int dccm_offset;
	bool is_coex;
};

struct aml_serdev {
	struct hci_uart serdev_hu;
	struct device *dev;
	struct gpio_desc *bt_en_gpio;
	struct regulator *bt_supply;
	struct clk *lpo_clk;
	const struct aml_device_data *aml_dev_data;
	const char *firmware_name;
};

struct aml_data {
	struct sk_buff *rx_skb;
	struct sk_buff_head txq;
};

static const struct h4_recv_pkt aml_recv_pkts[] = {
	{ H4_RECV_ACL, .recv = hci_recv_frame },
	{ H4_RECV_SCO, .recv = hci_recv_frame },
	{ H4_RECV_EVENT, .recv = hci_recv_frame },
	{ H4_RECV_ISO, .recv = hci_recv_frame },
};

/* The TCI command is a private command, which is for setting baud rate,
 * downloading firmware, initiating RAM.
 *
 * op_code |      op_len           | op_addr | parameter   |
 * --------|-----------------------|---------|-------------|
 *   2B    | 1B len(addr+param)    |    4B   |  len(param) |
 */
static int aml_send_tci_cmd(struct hci_dev *hdev, u16 op_code, u32 op_addr,
			    u32 *param, u32 param_len)
{
	struct aml_tci_rsp *rsp = NULL;
	struct sk_buff *skb = NULL;
	size_t buf_len = 0;
	u8 *buf = NULL;
	int err = 0;

	buf_len = sizeof(op_addr) + param_len;
	buf = kmalloc(buf_len, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	memcpy(buf, &op_addr, sizeof(op_addr));
	if (param && param_len > 0)
		memcpy(buf + sizeof(op_addr), param, param_len);

	skb = __hci_cmd_sync_ev(hdev, op_code, buf_len, buf,
				HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		err = PTR_ERR(skb);
		bt_dev_err(hdev, "Failed to send TCI cmd (error: %d)", err);
		goto exit;
	}

	rsp = skb_pull_data(skb, sizeof(struct aml_tci_rsp));
	if (!rsp)
		goto skb_free;

	if (rsp->opcode != op_code || rsp->status != 0x00) {
		bt_dev_err(hdev, "send TCI cmd (0x%04X), response (0x%04X):(%d)",
		       op_code, rsp->opcode, rsp->status);
		err = -EINVAL;
		goto skb_free;
	}

skb_free:
	kfree_skb(skb);

exit:
	kfree(buf);
	return err;
}

static int aml_update_chip_baudrate(struct hci_dev *hdev, u32 baud)
{
	u32 value;

	value = ((AML_UART_CLK_SOURCE / baud) - 1) & 0x0FFF;
	value |= AML_UART_XMIT_EN | AML_UART_RECV_EN | AML_UART_TIMEOUT_INT_EN;

	return aml_send_tci_cmd(hdev, AML_TCI_CMD_UPDATE_BAUDRATE,
				  AML_OP_UART_MODE, &value, sizeof(value));
}

static int aml_start_chip(struct hci_dev *hdev)
{
	u32 value = 0;
	int ret;

	value = AML_MM_CTR_HARD_TRAS_EN;
	ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
			       AML_OP_MEM_HARD_TRANS_EN,
			       &value, sizeof(value));
	if (ret)
		return ret;

	/* controller hardware reset */
	value = AML_CTR_CPU_RESET | AML_CTR_MAC_RESET | AML_CTR_PHY_RESET;
	ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_HARDWARE_RESET,
			       AML_OP_HARDWARE_RST,
			       &value, sizeof(value));
	return ret;
}

static int aml_send_firmware_segment(struct hci_dev *hdev,
				     u8 fw_type,
				     u8 *seg,
				     u32 seg_size,
				     u32 offset)
{
	u32 op_addr = 0;

	if (fw_type == FW_ICCM)
		op_addr = AML_OP_ICCM_RAM_BASE  + offset;
	else if (fw_type == FW_DCCM)
		op_addr = AML_OP_DCCM_RAM_BASE + offset;

	return aml_send_tci_cmd(hdev, AML_TCI_CMD_DOWNLOAD_BT_FW,
			     op_addr, (u32 *)seg, seg_size);
}

static int aml_send_firmware(struct hci_dev *hdev, u8 fw_type,
			     u8 *fw, u32 fw_size, u32 offset)
{
	u32 seg_size = 0;
	u32 seg_off = 0;

	if (fw_size > AML_FIRMWARE_MAX_SIZE) {
		bt_dev_err(hdev,
			"Firmware size %d kB is larger than the maximum of 512 kB. Aborting.",
			fw_size);
		return -EINVAL;
	}
	while (fw_size > 0) {
		seg_size = (fw_size > AML_FIRMWARE_OPERATION_SIZE) ?
			   AML_FIRMWARE_OPERATION_SIZE : fw_size;
		if (aml_send_firmware_segment(hdev, fw_type, (fw + seg_off),
					      seg_size, offset)) {
			bt_dev_err(hdev, "Failed send firmware, type: %d, offset: 0x%x",
			       fw_type, offset);
			return -EINVAL;
		}
		seg_off += seg_size;
		fw_size -= seg_size;
		offset += seg_size;
	}
	return 0;
}

static int aml_download_firmware(struct hci_dev *hdev, const char *fw_name)
{
	struct hci_uart *hu = hci_get_drvdata(hdev);
	struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
	const struct firmware *firmware = NULL;
	struct aml_fw_len *fw_len = NULL;
	u8 *iccm_start = NULL, *dccm_start = NULL;
	u32 iccm_len, dccm_len;
	u32 value = 0;
	int ret = 0;

	/* Enable firmware download event */
	value = AML_EVT_EN;
	ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
			       AML_OP_EVT_ENABLE,
			       &value, sizeof(value));
	if (ret)
		goto exit;

	/* RAM power on */
	value = AML_RAM_POWER_ON;
	ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
			       AML_OP_RAM_POWER_CTR,
			       &value, sizeof(value));
	if (ret)
		goto exit;

	/* Check RAM power status */
	ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_READ,
			       AML_OP_RAM_POWER_CTR, NULL, 0);
	if (ret)
		goto exit;

	ret = request_firmware(&firmware, fw_name, &hdev->dev);
	if (ret < 0) {
		bt_dev_err(hdev, "Failed to load <%s>:(%d)", fw_name, ret);
		goto exit;
	}

	fw_len = (struct aml_fw_len *)firmware->data;

	/* Download ICCM */
	iccm_start = (u8 *)(firmware->data) + sizeof(struct aml_fw_len)
			+ amldev->aml_dev_data->iccm_offset;
	iccm_len = fw_len->iccm_len - amldev->aml_dev_data->iccm_offset;
	ret = aml_send_firmware(hdev, FW_ICCM, iccm_start, iccm_len,
				amldev->aml_dev_data->iccm_offset);
	if (ret) {
		bt_dev_err(hdev, "Failed to send FW_ICCM (%d)", ret);
		goto exit;
	}

	/* Download DCCM */
	dccm_start = (u8 *)(firmware->data) + sizeof(struct aml_fw_len) + fw_len->iccm_len;
	dccm_len = fw_len->dccm_len;
	ret = aml_send_firmware(hdev, FW_DCCM, dccm_start, dccm_len,
				amldev->aml_dev_data->dccm_offset);
	if (ret) {
		bt_dev_err(hdev, "Failed to send FW_DCCM (%d)", ret);
		goto exit;
	}

	/* Disable firmware download event */
	value = 0;
	ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
			       AML_OP_EVT_ENABLE,
			       &value, sizeof(value));
	if (ret)
		goto exit;

exit:
	if (firmware)
		release_firmware(firmware);
	return ret;
}

static int aml_send_reset(struct hci_dev *hdev)
{
	struct sk_buff *skb;
	int err;

	skb = __hci_cmd_sync_ev(hdev, HCI_OP_RESET, 0, NULL,
				HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		err = PTR_ERR(skb);
		bt_dev_err(hdev, "Failed to send hci reset cmd (%d)", err);
		return err;
	}

	kfree_skb(skb);
	return 0;
}

static int aml_dump_fw_version(struct hci_dev *hdev)
{
	struct aml_tci_rsp *rsp = NULL;
	struct sk_buff *skb;
	u8 value[6] = {0};
	u8 *fw_ver = NULL;
	int err = 0;

	skb = __hci_cmd_sync_ev(hdev, AML_BT_HCI_VENDOR_CMD, sizeof(value), value,
				HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		err = PTR_ERR(skb);
		bt_dev_err(hdev, "Failed to get fw version (error: %d)", err);
		return err;
	}

	rsp = skb_pull_data(skb, sizeof(struct aml_tci_rsp));
	if (!rsp)
		goto exit;

	if (rsp->opcode != AML_BT_HCI_VENDOR_CMD || rsp->status != 0x00) {
		bt_dev_err(hdev, "dump version, error response (0x%04X):(%d)",
		       rsp->opcode, rsp->status);
		err = -EINVAL;
		goto exit;
	}

	fw_ver = (u8 *)rsp + AML_EVT_HEAD_SIZE;
	bt_dev_info(hdev, "fw_version: date = %02x.%02x, number = 0x%02x%02x",
		*(fw_ver + 1), *fw_ver, *(fw_ver + 3), *(fw_ver + 2));

exit:
	kfree_skb(skb);
	return err;
}

static int aml_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
{
	struct aml_tci_rsp *rsp = NULL;
	struct sk_buff *skb;
	int err = 0;

	bt_dev_info(hdev, "set bdaddr (%pM)", bdaddr);
	skb = __hci_cmd_sync_ev(hdev, AML_BT_HCI_VENDOR_CMD,
				sizeof(bdaddr_t), bdaddr,
				HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		err = PTR_ERR(skb);
		bt_dev_err(hdev, "Failed to set bdaddr (error: %d)", err);
		return err;
	}

	rsp = skb_pull_data(skb, sizeof(struct aml_tci_rsp));
	if (!rsp)
		goto exit;

	if (rsp->opcode != AML_BT_HCI_VENDOR_CMD || rsp->status != 0x00) {
		bt_dev_err(hdev, "error response (0x%x):(%d)", rsp->opcode, rsp->status);
		err = -EINVAL;
		goto exit;
	}

exit:
	kfree_skb(skb);
	return err;
}

static int aml_check_bdaddr(struct hci_dev *hdev)
{
	struct hci_rp_read_bd_addr *paddr;
	struct sk_buff *skb;
	int err;

	if (bacmp(&hdev->public_addr, BDADDR_ANY))
		return 0;

	skb = __hci_cmd_sync(hdev, HCI_OP_READ_BD_ADDR, 0, NULL,
			     HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
		err = PTR_ERR(skb);
		bt_dev_err(hdev, "Failed to read bdaddr (error: %d)", err);
		return err;
	}

	paddr = skb_pull_data(skb, sizeof(struct hci_rp_read_bd_addr));
	if (!paddr)
		goto exit;

	if (!bacmp(&paddr->bdaddr, AML_BDADDR_DEFAULT)) {
		bt_dev_info(hdev, "amlbt using default bdaddr (%pM)", &paddr->bdaddr);
		set_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks);
	}

exit:
	kfree_skb(skb);
	return 0;
}

static int aml_config_rf(struct hci_dev *hdev, bool is_coex)
{
	u32 value = AML_RF_ANT_DOUBLE;

	/* Use a single antenna when co-existing with wifi */
	if (is_coex)
		value = AML_RF_ANT_SINGLE;

	return aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
				AML_OP_RF_CFG,
				&value, sizeof(value));
}

static int aml_parse_dt(struct aml_serdev *amldev)
{
	struct device *pdev = amldev->dev;

	amldev->bt_en_gpio = devm_gpiod_get(pdev, "enable",
					GPIOD_OUT_LOW);
	if (IS_ERR(amldev->bt_en_gpio)) {
		dev_err(pdev, "Failed to acquire enable gpios");
		return PTR_ERR(amldev->bt_en_gpio);
	}

	if (device_property_read_string(pdev, "firmware-name",
					&amldev->firmware_name)) {
		dev_err(pdev, "Failed to acquire firmware path");
		return -ENODEV;
	}

	amldev->bt_supply = devm_regulator_get(pdev, "vddio");
	if (IS_ERR(amldev->bt_supply)) {
		dev_err(pdev, "Failed to acquire regulator");
		return PTR_ERR(amldev->bt_supply);
	}

	amldev->lpo_clk = devm_clk_get(pdev, NULL);
	if (IS_ERR(amldev->lpo_clk)) {
		dev_err(pdev, "Failed to acquire clock source");
		return PTR_ERR(amldev->lpo_clk);
	}

	return 0;
}

static int aml_power_on(struct aml_serdev *amldev)
{
	int err;

	err = regulator_enable(amldev->bt_supply);
	if (err) {
		dev_err(amldev->dev, "Failed to enable regulator: (%d)", err);
		return err;
	}

	err = clk_prepare_enable(amldev->lpo_clk);
	if (err) {
		dev_err(amldev->dev, "Failed to enable lpo clock: (%d)", err);
		return err;
	}

	gpiod_set_value_cansleep(amldev->bt_en_gpio, 1);

	/* Wait 20ms for bluetooth controller power on */
	msleep(20);
	return 0;
}

static int aml_power_off(struct aml_serdev *amldev)
{
	gpiod_set_value_cansleep(amldev->bt_en_gpio, 0);

	clk_disable_unprepare(amldev->lpo_clk);

	regulator_disable(amldev->bt_supply);

	return 0;
}

static int aml_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
	/* update controller baudrate */
	if (aml_update_chip_baudrate(hu->hdev, speed) != 0) {
		bt_dev_err(hu->hdev, "Failed to update baud rate");
		return -EINVAL;
	}

	/* update local baudrate */
	serdev_device_set_baudrate(hu->serdev, speed);

	return 0;
}

/* Initialize protocol */
static int aml_open(struct hci_uart *hu)
{
	struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
	struct aml_data *aml_data;
	int err;

	err = aml_parse_dt(amldev);
	if (err)
		return err;

	if (!hci_uart_has_flow_control(hu)) {
		bt_dev_err(hu->hdev, "no flow control");
		return -EOPNOTSUPP;
	}

	aml_data = kzalloc(sizeof(*aml_data), GFP_KERNEL);
	if (!aml_data)
		return -ENOMEM;

	skb_queue_head_init(&aml_data->txq);

	hu->priv = aml_data;

	return 0;
}

static int aml_close(struct hci_uart *hu)
{
	struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
	struct aml_data *aml_data = hu->priv;

	skb_queue_purge(&aml_data->txq);
	kfree_skb(aml_data->rx_skb);
	kfree(aml_data);

	hu->priv = NULL;

	return aml_power_off(amldev);
}

static int aml_flush(struct hci_uart *hu)
{
	struct aml_data *aml_data = hu->priv;

	skb_queue_purge(&aml_data->txq);

	return 0;
}

static int aml_setup(struct hci_uart *hu)
{
	struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
	struct hci_dev *hdev = amldev->serdev_hu.hdev;
	int err;

	/* Setup bdaddr */
	hdev->set_bdaddr = aml_set_bdaddr;

	err = aml_power_on(amldev);
	if (err)
		return err;

	err = aml_set_baudrate(hu, amldev->serdev_hu.proto->oper_speed);
	if (err)
		return err;

	err = aml_download_firmware(hdev, amldev->firmware_name);
	if (err)
		return err;

	err = aml_config_rf(hdev, amldev->aml_dev_data->is_coex);
	if (err)
		return err;

	err = aml_start_chip(hdev);
	if (err)
		return err;

	/* Wait 60ms for controller startup */
	msleep(60);

	err = aml_dump_fw_version(hdev);
	if (err)
		return err;

	err = aml_send_reset(hdev);
	if (err)
		return err;

	err = aml_check_bdaddr(hdev);
	if (err)
		return err;

	return 0;
}

static int aml_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
	struct aml_data *aml_data = hu->priv;

	skb_queue_tail(&aml_data->txq, skb);

	return 0;
}

static struct sk_buff *aml_dequeue(struct hci_uart *hu)
{
	struct aml_data *aml_data = hu->priv;
	struct sk_buff *skb;

	skb = skb_dequeue(&aml_data->txq);

	/* Prepend skb with frame type */
	if (skb)
		memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);

	return skb;
}

static int aml_recv(struct hci_uart *hu, const void *data, int count)
{
	struct aml_data *aml_data = hu->priv;
	int err;

	aml_data->rx_skb = h4_recv_buf(hu->hdev, aml_data->rx_skb, data, count,
				       aml_recv_pkts,
				       ARRAY_SIZE(aml_recv_pkts));
	if (IS_ERR(aml_data->rx_skb)) {
		err = PTR_ERR(aml_data->rx_skb);
		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
		aml_data->rx_skb = NULL;
		return err;
	}

	return count;
}

static const struct hci_uart_proto aml_hci_proto = {
	.id		= HCI_UART_AML,
	.name		= "AML",
	.init_speed	= 115200,
	.oper_speed	= 4000000,
	.open		= aml_open,
	.close		= aml_close,
	.setup		= aml_setup,
	.flush		= aml_flush,
	.recv		= aml_recv,
	.enqueue	= aml_enqueue,
	.dequeue	= aml_dequeue,
};

static void aml_device_driver_shutdown(struct device *dev)
{
	struct aml_serdev *amldev = dev_get_drvdata(dev);

	aml_power_off(amldev);
}

static int aml_serdev_probe(struct serdev_device *serdev)
{
	struct aml_serdev *amldev;
	int err;

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

	amldev->serdev_hu.serdev = serdev;
	amldev->dev = &serdev->dev;
	serdev_device_set_drvdata(serdev, amldev);

	err = hci_uart_register_device(&amldev->serdev_hu, &aml_hci_proto);
	if (err)
		return dev_err_probe(amldev->dev, err,
			      "Failed to register hci uart device");

	amldev->aml_dev_data = device_get_match_data(&serdev->dev);

	return 0;
}

static void aml_serdev_remove(struct serdev_device *serdev)
{
	struct aml_serdev *amldev = serdev_device_get_drvdata(serdev);

	hci_uart_unregister_device(&amldev->serdev_hu);
}

static const struct aml_device_data data_w155s2 = {
	.iccm_offset = 256 * 1024,
};

static const struct aml_device_data data_w265s2 = {
	.iccm_offset = 384 * 1024,
};

static const struct of_device_id aml_bluetooth_of_match[] = {
	{ .compatible = "amlogic,w155s2-bt", .data = &data_w155s2 },
	{ .compatible = "amlogic,w265s2-bt", .data = &data_w265s2 },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, aml_bluetooth_of_match);

static struct serdev_device_driver aml_serdev_driver = {
	.probe = aml_serdev_probe,
	.remove = aml_serdev_remove,
	.driver = {
		.name = "hci_uart_aml",
		.of_match_table = aml_bluetooth_of_match,
		.shutdown = aml_device_driver_shutdown,
	},
};

int __init aml_init(void)
{
	serdev_device_driver_register(&aml_serdev_driver);

	return hci_uart_register_proto(&aml_hci_proto);
}

int __exit aml_deinit(void)
{
	serdev_device_driver_unregister(&aml_serdev_driver);

	return hci_uart_unregister_proto(&aml_hci_proto);
}