/*
 * Wireless / Bluetooth USB class
 *
 * Copyright (c) 2018 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <init.h>

#include <usb/usb_device.h>
#include <usb/usb_common.h>
#include <usb_descriptor.h>

#include <net/buf.h>

#include <bluetooth/buf.h>
#include <bluetooth/hci_raw.h>
#include <bluetooth/l2cap.h>

#define SYS_LOG_LEVEL SYS_LOG_LEVEL_WARNING
#define SYS_LOG_DOMAIN "usb/bluetooth"
#include <logging/sys_log.h>

#if !defined(CONFIG_USB_COMPOSITE_DEVICE)
static u8_t interface_data[64];
#endif

static K_FIFO_DEFINE(rx_queue);

/* HCI command buffers */
#define CMD_BUF_SIZE BT_BUF_RX_SIZE
NET_BUF_POOL_DEFINE(tx_pool, CONFIG_BT_HCI_CMD_COUNT, CMD_BUF_SIZE,
		    sizeof(u8_t), NULL);

#define BT_L2CAP_MTU 64
/* Data size needed for ACL buffers */
#define BT_BUF_ACL_SIZE BT_L2CAP_BUF_SIZE(BT_L2CAP_MTU)
NET_BUF_POOL_DEFINE(acl_tx_pool, 2, BT_BUF_ACL_SIZE, sizeof(u8_t), NULL);

/* Stack for thread */
static K_THREAD_STACK_DEFINE(bluetooth_thread_stack, 512);
static struct k_thread bluetooth_thread_data;

static void bluetooth_status_cb(enum usb_dc_status_code status, u8_t *param)
{
	/* Check the USB status and do needed action if required */
	switch (status) {
	case USB_DC_ERROR:
		SYS_LOG_DBG("USB device error");
		break;
	case USB_DC_RESET:
		SYS_LOG_DBG("USB device reset detected");
		break;
	case USB_DC_CONNECTED:
		SYS_LOG_DBG("USB device connected");
		break;
	case USB_DC_CONFIGURED:
		SYS_LOG_DBG("USB device configured");
		break;
	case USB_DC_DISCONNECTED:
		SYS_LOG_DBG("USB device disconnected");
		break;
	case USB_DC_SUSPEND:
		SYS_LOG_DBG("USB device suspended");
		break;
	case USB_DC_RESUME:
		SYS_LOG_DBG("USB device resumed");
		break;
	case USB_DC_UNKNOWN:
	default:
		SYS_LOG_DBG("USB unknown state");
		break;
	}
}

static void bluetooth_thread(void)
{
	SYS_LOG_DBG("Start USB Bluetooth thread");

	while (true) {
		struct net_buf *buf;

		buf = net_buf_get(&rx_queue, K_FOREVER);

		switch (bt_buf_get_type(buf)) {
		case BT_BUF_EVT:
			usb_transfer_sync(CONFIG_BLUETOOTH_INT_EP_ADDR,
					  buf->data, buf->len,
					  USB_TRANS_WRITE);
			break;
		case BT_BUF_ACL_IN:
			usb_transfer_sync(CONFIG_BLUETOOTH_IN_EP_ADDR,
					  buf->data, buf->len,
					  USB_TRANS_WRITE);
			break;
		default:
			SYS_LOG_ERR("Unknown type %u", bt_buf_get_type(buf));
			break;
		}

		net_buf_unref(buf);
	}
}

static void bluetooth_bulk_out_callback(u8_t ep,
					enum usb_dc_ep_cb_status_code ep_status)
{
	struct net_buf *buf;
	u32_t len;

	SYS_LOG_DBG("ep %x status %d", ep, ep_status);

	/* Read number of bytes to read */
	usb_read(ep, NULL, 0, &len);

	if (!len || len > BT_BUF_ACL_SIZE) {
		SYS_LOG_ERR("Incorrect length: %u\n", len);
		return;
	}

	buf = net_buf_alloc(&acl_tx_pool, K_NO_WAIT);
	if (!buf) {
		SYS_LOG_ERR("Cannot get free buffer\n");
		return;
	}

	usb_read(ep, net_buf_add(buf, len), len, NULL);

	bt_buf_set_type(buf, BT_BUF_ACL_OUT);

	bt_send(buf);
}

static int bluetooth_class_handler(struct usb_setup_packet *setup,
				   s32_t *len, u8_t **data)
{
	struct net_buf *buf;

	SYS_LOG_DBG("len %u", *len);

	if (!*len || *len > CMD_BUF_SIZE) {
		SYS_LOG_ERR("Incorrect length: %d\n", *len);
		return -EINVAL;
	}

	buf = net_buf_alloc(&tx_pool, K_NO_WAIT);
	if (!buf) {
		SYS_LOG_ERR("Cannot get free buffer\n");
		return -ENOMEM;
	}

	bt_buf_set_type(buf, BT_BUF_CMD);

	net_buf_add_mem(buf, *data, *len);

	bt_send(buf);

	return 0;
}

static struct usb_ep_cfg_data bluetooth_ep_data[] = {
	{
		.ep_cb = usb_transfer_ep_callback,
		.ep_addr = CONFIG_BLUETOOTH_INT_EP_ADDR,
	},
	{
		.ep_cb = bluetooth_bulk_out_callback,
		.ep_addr = CONFIG_BLUETOOTH_OUT_EP_ADDR,
	},
	{
		.ep_cb = usb_transfer_ep_callback,
		.ep_addr = CONFIG_BLUETOOTH_IN_EP_ADDR,
	},
};

static struct usb_cfg_data bluetooth_config = {
	.usb_device_description = NULL,
	.cb_usb_status = bluetooth_status_cb,
	.interface = {
		.class_handler = bluetooth_class_handler,
		.custom_handler = NULL,
		.vendor_handler = NULL,
		.payload_data = NULL,
	},
	.num_endpoints = NUMOF_ENDPOINTS_BLUETOOTH,
	.endpoint = bluetooth_ep_data,
};

static int bluetooth_init(struct device *dev)
{
	int ret;

	SYS_LOG_DBG("Initialization");

	ret = bt_enable_raw(&rx_queue);
	if (ret) {
		SYS_LOG_ERR("Failed to open Bluetooth raw channel: %d", ret);
		return ret;
	}

#ifdef CONFIG_USB_COMPOSITE_DEVICE
	ret = composite_add_function(&bluetooth_config,
				     FIRST_IFACE_BLUETOOTH);
	if (ret < 0) {
		SYS_LOG_ERR("Failed to add bluetooth function");
		return ret;
	}
#else
	bluetooth_config.interface.payload_data = interface_data;
	bluetooth_config.usb_device_description =
		usb_get_device_descriptor();
	/* Initialize the USB driver with the right configuration */
	ret = usb_set_config(&bluetooth_config);
	if (ret < 0) {
		SYS_LOG_ERR("Failed to config USB");
		return ret;
	}

	/* Enable USB driver */
	ret = usb_enable(&bluetooth_config);
	if (ret < 0) {
		SYS_LOG_ERR("Failed to enable USB");
		return ret;
	}
#endif

	k_thread_create(&bluetooth_thread_data, bluetooth_thread_stack,
			K_THREAD_STACK_SIZEOF(bluetooth_thread_stack),
			(k_thread_entry_t)bluetooth_thread,
			NULL, NULL, NULL, K_PRIO_COOP(8), 0, K_NO_WAIT);

	return 0;
}

SYS_INIT(bluetooth_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);