// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 *  Broadcom Blutonium firmware driver
 *
 *  Copyright (C) 2003  Maxim Krasnyansky <maxk@qualcomm.com>
 *  Copyright (C) 2003  Marcel Holtmann <marcel@holtmann.org>
 */

#include <linux/module.h>

#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/errno.h>

#include <linux/device.h>
#include <linux/firmware.h>

#include <linux/usb.h>

#include <net/bluetooth/bluetooth.h>

#define VERSION "1.2"

static const struct usb_device_id bcm203x_table[] = {
	/* Broadcom Blutonium (BCM2033) */
	{ USB_DEVICE(0x0a5c, 0x2033) },

	{ }	/* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, bcm203x_table);

#define BCM203X_ERROR		0
#define BCM203X_RESET		1
#define BCM203X_LOAD_MINIDRV	2
#define BCM203X_SELECT_MEMORY	3
#define BCM203X_CHECK_MEMORY	4
#define BCM203X_LOAD_FIRMWARE	5
#define BCM203X_CHECK_FIRMWARE	6

#define BCM203X_IN_EP		0x81
#define BCM203X_OUT_EP		0x02

struct bcm203x_data {
	struct usb_device	*udev;

	unsigned long		state;

	struct work_struct	work;
	atomic_t		shutdown;

	struct urb		*urb;
	unsigned char		*buffer;

	unsigned char		*fw_data;
	unsigned int		fw_size;
	unsigned int		fw_sent;
};

static void bcm203x_complete(struct urb *urb)
{
	struct bcm203x_data *data = urb->context;
	struct usb_device *udev = urb->dev;
	int len;

	BT_DBG("udev %p urb %p", udev, urb);

	if (urb->status) {
		BT_ERR("URB failed with status %d", urb->status);
		data->state = BCM203X_ERROR;
		return;
	}

	switch (data->state) {
	case BCM203X_LOAD_MINIDRV:
		memcpy(data->buffer, "#", 1);

		usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, BCM203X_OUT_EP),
				data->buffer, 1, bcm203x_complete, data);

		data->state = BCM203X_SELECT_MEMORY;

		/* use workqueue to have a small delay */
		schedule_work(&data->work);
		break;

	case BCM203X_SELECT_MEMORY:
		usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, BCM203X_IN_EP),
				data->buffer, 32, bcm203x_complete, data, 1);

		data->state = BCM203X_CHECK_MEMORY;

		if (usb_submit_urb(data->urb, GFP_ATOMIC) < 0)
			BT_ERR("Can't submit URB");
		break;

	case BCM203X_CHECK_MEMORY:
		if (data->buffer[0] != '#') {
			BT_ERR("Memory select failed");
			data->state = BCM203X_ERROR;
			break;
		}

		data->state = BCM203X_LOAD_FIRMWARE;
		/* fall through */
	case BCM203X_LOAD_FIRMWARE:
		if (data->fw_sent == data->fw_size) {
			usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, BCM203X_IN_EP),
				data->buffer, 32, bcm203x_complete, data, 1);

			data->state = BCM203X_CHECK_FIRMWARE;
		} else {
			len = min_t(uint, data->fw_size - data->fw_sent, 4096);

			usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, BCM203X_OUT_EP),
				data->fw_data + data->fw_sent, len, bcm203x_complete, data);

			data->fw_sent += len;
		}

		if (usb_submit_urb(data->urb, GFP_ATOMIC) < 0)
			BT_ERR("Can't submit URB");
		break;

	case BCM203X_CHECK_FIRMWARE:
		if (data->buffer[0] != '.') {
			BT_ERR("Firmware loading failed");
			data->state = BCM203X_ERROR;
			break;
		}

		data->state = BCM203X_RESET;
		break;
	}
}

static void bcm203x_work(struct work_struct *work)
{
	struct bcm203x_data *data =
		container_of(work, struct bcm203x_data, work);

	if (atomic_read(&data->shutdown))
		return;

	if (usb_submit_urb(data->urb, GFP_KERNEL) < 0)
		BT_ERR("Can't submit URB");
}

static int bcm203x_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
	const struct firmware *firmware;
	struct usb_device *udev = interface_to_usbdev(intf);
	struct bcm203x_data *data;
	int size;

	BT_DBG("intf %p id %p", intf, id);

	if (intf->cur_altsetting->desc.bInterfaceNumber != 0)
		return -ENODEV;

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

	data->udev  = udev;
	data->state = BCM203X_LOAD_MINIDRV;

	data->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!data->urb)
		return -ENOMEM;

	if (request_firmware(&firmware, "BCM2033-MD.hex", &udev->dev) < 0) {
		BT_ERR("Mini driver request failed");
		usb_free_urb(data->urb);
		return -EIO;
	}

	BT_DBG("minidrv data %p size %zu", firmware->data, firmware->size);

	size = max_t(uint, firmware->size, 4096);

	data->buffer = kmalloc(size, GFP_KERNEL);
	if (!data->buffer) {
		BT_ERR("Can't allocate memory for mini driver");
		release_firmware(firmware);
		usb_free_urb(data->urb);
		return -ENOMEM;
	}

	memcpy(data->buffer, firmware->data, firmware->size);

	usb_fill_bulk_urb(data->urb, udev, usb_sndbulkpipe(udev, BCM203X_OUT_EP),
			data->buffer, firmware->size, bcm203x_complete, data);

	release_firmware(firmware);

	if (request_firmware(&firmware, "BCM2033-FW.bin", &udev->dev) < 0) {
		BT_ERR("Firmware request failed");
		usb_free_urb(data->urb);
		kfree(data->buffer);
		return -EIO;
	}

	BT_DBG("firmware data %p size %zu", firmware->data, firmware->size);

	data->fw_data = kmemdup(firmware->data, firmware->size, GFP_KERNEL);
	if (!data->fw_data) {
		BT_ERR("Can't allocate memory for firmware image");
		release_firmware(firmware);
		usb_free_urb(data->urb);
		kfree(data->buffer);
		return -ENOMEM;
	}

	data->fw_size = firmware->size;
	data->fw_sent = 0;

	release_firmware(firmware);

	INIT_WORK(&data->work, bcm203x_work);

	usb_set_intfdata(intf, data);

	/* use workqueue to have a small delay */
	schedule_work(&data->work);

	return 0;
}

static void bcm203x_disconnect(struct usb_interface *intf)
{
	struct bcm203x_data *data = usb_get_intfdata(intf);

	BT_DBG("intf %p", intf);

	atomic_inc(&data->shutdown);
	cancel_work_sync(&data->work);

	usb_kill_urb(data->urb);

	usb_set_intfdata(intf, NULL);

	usb_free_urb(data->urb);
	kfree(data->fw_data);
	kfree(data->buffer);
}

static struct usb_driver bcm203x_driver = {
	.name		= "bcm203x",
	.probe		= bcm203x_probe,
	.disconnect	= bcm203x_disconnect,
	.id_table	= bcm203x_table,
	.disable_hub_initiated_lpm = 1,
};

module_usb_driver(bcm203x_driver);

MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Broadcom Blutonium firmware driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("BCM2033-MD.hex");
MODULE_FIRMWARE("BCM2033-FW.bin");