sound/usb/6fire/firmware.c - kernel/msm-4.19 - Gitiles

 /*
  * Linux driver for TerraTec DMX 6Fire USB
  *
  * Firmware loader
  *
  * Author:	Torsten Schenk <torsten.schenk@zoho.com>
  * Created:	Jan 01, 2011
  * Version:	0.3.0
  * Copyright:	(C) Torsten Schenk
  *
  * 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.
  */

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

 #include "firmware.h"
 #include "chip.h"

 MODULE_FIRMWARE("6fire/dmx6firel2.ihx");
 MODULE_FIRMWARE("6fire/dmx6fireap.ihx");
 MODULE_FIRMWARE("6fire/dmx6firecf.bin");

 enum {
 	FPGA_BUFSIZE = 512, FPGA_EP = 2
 };

 /*
  * wMaxPacketSize of pcm endpoints.
  * keep synced with rates_in_packet_size and rates_out_packet_size in pcm.c
  * fpp: frames per isopacket
  *
  * CAUTION: keep sizeof <= buffer[] in usb6fire_fw_init
  */
 static const u8 ep_w_max_packet_size[] = {
 	0xe4, 0x00, 0xe4, 0x00, /* alt 1: 228 EP2 and EP6 (7 fpp) */
 	0xa4, 0x01, 0xa4, 0x01, /* alt 2: 420 EP2 and EP6 (13 fpp)*/
 	0x94, 0x01, 0x5c, 0x02  /* alt 3: 404 EP2 and 604 EP6 (25 fpp) */
 };

 static const u8 known_fw_versions[][4] = {
 	{ 0x03, 0x01, 0x0b, 0x00 }
 };

 struct ihex_record {
 	u16 address;
 	u8 len;
 	u8 data[256];
 	char error; /* true if an error occurred parsing this record */

 	u8 max_len; /* maximum record length in whole ihex */

 	/* private */
 	const char *txt_data;
 	unsigned int txt_length;
 	unsigned int txt_offset; /* current position in txt_data */
 };

 static u8 usb6fire_fw_ihex_nibble(const u8 n)
 {
 	if (n >= '0' && n <= '9')
 		return n - '0';
 	else if (n >= 'A' && n <= 'F')
 		return n - ('A' - 10);
 	else if (n >= 'a' && n <= 'f')
 		return n - ('a' - 10);
 	return 0;
 }

 static u8 usb6fire_fw_ihex_hex(const u8 *data, u8 *crc)
 {
 	u8 val = (usb6fire_fw_ihex_nibble(data[0]) << 4) |
 			usb6fire_fw_ihex_nibble(data[1]);
 	*crc += val;
 	return val;
 }

 /*
  * returns true if record is available, false otherwise.
  * iff an error occurred, false will be returned and record->error will be true.
  */
 static bool usb6fire_fw_ihex_next_record(struct ihex_record *record)
 {
 	u8 crc = 0;
 	u8 type;
 	int i;

 	record->error = false;

 	/* find begin of record (marked by a colon) */
 	while (record->txt_offset < record->txt_length
 			&& record->txt_data[record->txt_offset] != ':')
 		record->txt_offset++;
 	if (record->txt_offset == record->txt_length)
 		return false;

 	/* number of characters needed for len, addr and type entries */
 	record->txt_offset++;
 	if (record->txt_offset + 8 > record->txt_length) {
 		record->error = true;
 		return false;
 	}

 	record->len = usb6fire_fw_ihex_hex(record->txt_data +
 			record->txt_offset, &crc);
 	record->txt_offset += 2;
 	record->address = usb6fire_fw_ihex_hex(record->txt_data +
 			record->txt_offset, &crc) << 8;
 	record->txt_offset += 2;
 	record->address |= usb6fire_fw_ihex_hex(record->txt_data +
 			record->txt_offset, &crc);
 	record->txt_offset += 2;
 	type = usb6fire_fw_ihex_hex(record->txt_data +
 			record->txt_offset, &crc);
 	record->txt_offset += 2;

 	/* number of characters needed for data and crc entries */
 	if (record->txt_offset + 2 * (record->len + 1) > record->txt_length) {
 		record->error = true;
 		return false;
 	}
 	for (i = 0; i < record->len; i++) {
 		record->data[i] = usb6fire_fw_ihex_hex(record->txt_data
 				+ record->txt_offset, &crc);
 		record->txt_offset += 2;
 	}
 	usb6fire_fw_ihex_hex(record->txt_data + record->txt_offset, &crc);
 	if (crc) {
 		record->error = true;
 		return false;
 	}

 	if (type == 1 || !record->len) /* eof */
 		return false;
 	else if (type == 0)
 		return true;
 	else {
 		record->error = true;
 		return false;
 	}
 }

 static int usb6fire_fw_ihex_init(const struct firmware *fw,
 		struct ihex_record *record)
 {
 	record->txt_data = fw->data;
 	record->txt_length = fw->size;
 	record->txt_offset = 0;
 	record->max_len = 0;
 	/* read all records, if loop ends, record->error indicates,
 	 * whether ihex is valid. */
 	while (usb6fire_fw_ihex_next_record(record))
 		record->max_len = max(record->len, record->max_len);
 	if (record->error)
 		return -EINVAL;
 	record->txt_offset = 0;
 	return 0;
 }

 static int usb6fire_fw_ezusb_write(struct usb_device *device,
 		int type, int value, char *data, int len)
 {
 	int ret;

 	ret = usb_control_msg(device, usb_sndctrlpipe(device, 0), type,
 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 			value, 0, data, len, HZ);
 	if (ret < 0)
 		return ret;
 	else if (ret != len)
 		return -EIO;
 	return 0;
 }

 static int usb6fire_fw_ezusb_read(struct usb_device *device,
 		int type, int value, char *data, int len)
 {
 	int ret = usb_control_msg(device, usb_rcvctrlpipe(device, 0), type,
 			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, value,
 			0, data, len, HZ);
 	if (ret < 0)
 		return ret;
 	else if (ret != len)
 		return -EIO;
 	return 0;
 }

 static int usb6fire_fw_fpga_write(struct usb_device *device,
 		char *data, int len)
 {
 	int actual_len;
 	int ret;

 	ret = usb_bulk_msg(device, usb_sndbulkpipe(device, FPGA_EP), data, len,
 			&actual_len, HZ);
 	if (ret < 0)
 		return ret;
 	else if (actual_len != len)
 		return -EIO;
 	return 0;
 }

 static int usb6fire_fw_ezusb_upload(
 		struct usb_interface *intf, const char *fwname,
 		unsigned int postaddr, u8 *postdata, unsigned int postlen)
 {
 	int ret;
 	u8 data;
 	struct usb_device *device = interface_to_usbdev(intf);
 	const struct firmware *fw = 0;
 	struct ihex_record *rec = kmalloc(sizeof(struct ihex_record),
 			GFP_KERNEL);

 	if (!rec)
 		return -ENOMEM;

 	ret = request_firmware(&fw, fwname, &device->dev);
 	if (ret < 0) {
 		kfree(rec);
 		snd_printk(KERN_ERR PREFIX "error requesting ezusb "
 				"firmware %s.\n", fwname);
 		return ret;
 	}
 	ret = usb6fire_fw_ihex_init(fw, rec);
 	if (ret < 0) {
 		kfree(rec);
 		release_firmware(fw);
 		snd_printk(KERN_ERR PREFIX "error validating ezusb "
 				"firmware %s.\n", fwname);
 		return ret;
 	}
 	/* upload firmware image */
 	data = 0x01; /* stop ezusb cpu */
 	ret = usb6fire_fw_ezusb_write(device, 0xa0, 0xe600, &data, 1);
 	if (ret < 0) {
 		kfree(rec);
 		release_firmware(fw);
 		snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
 				"firmware %s: begin message.\n", fwname);
 		return ret;
 	}

 	while (usb6fire_fw_ihex_next_record(rec)) { /* write firmware */
 		ret = usb6fire_fw_ezusb_write(device, 0xa0, rec->address,
 				rec->data, rec->len);
 		if (ret < 0) {
 			kfree(rec);
 			release_firmware(fw);
 			snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
 					"firmware %s: data urb.\n", fwname);
 			return ret;
 		}
 	}

 	release_firmware(fw);
 	kfree(rec);
 	if (postdata) { /* write data after firmware has been uploaded */
 		ret = usb6fire_fw_ezusb_write(device, 0xa0, postaddr,
 				postdata, postlen);
 		if (ret < 0) {
 			snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
 					"firmware %s: post urb.\n", fwname);
 			return ret;
 		}
 	}

 	data = 0x00; /* resume ezusb cpu */
 	ret = usb6fire_fw_ezusb_write(device, 0xa0, 0xe600, &data, 1);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
 				"firmware %s: end message.\n", fwname);
 		return ret;
 	}
 	return 0;
 }

 static int usb6fire_fw_fpga_upload(
 		struct usb_interface *intf, const char *fwname)
 {
 	int ret;
 	int i;
 	struct usb_device *device = interface_to_usbdev(intf);
 	u8 *buffer = kmalloc(FPGA_BUFSIZE, GFP_KERNEL);
 	const char *c;
 	const char *end;
 	const struct firmware *fw;

 	if (!buffer)
 		return -ENOMEM;

 	ret = request_firmware(&fw, fwname, &device->dev);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "unable to get fpga firmware %s.\n",
 				fwname);
 		kfree(buffer);
 		return -EIO;
 	}

 	c = fw->data;
 	end = fw->data + fw->size;

 	ret = usb6fire_fw_ezusb_write(device, 8, 0, NULL, 0);
 	if (ret < 0) {
 		kfree(buffer);
 		release_firmware(fw);
 		snd_printk(KERN_ERR PREFIX "unable to upload fpga firmware: "
 				"begin urb.\n");
 		return ret;
 	}

 	while (c != end) {
 		for (i = 0; c != end && i < FPGA_BUFSIZE; i++, c++)
 			buffer[i] = byte_rev_table[(u8) *c];

 		ret = usb6fire_fw_fpga_write(device, buffer, i);
 		if (ret < 0) {
 			release_firmware(fw);
 			kfree(buffer);
 			snd_printk(KERN_ERR PREFIX "unable to upload fpga "
 					"firmware: fw urb.\n");
 			return ret;
 		}
 	}
 	release_firmware(fw);
 	kfree(buffer);

 	ret = usb6fire_fw_ezusb_write(device, 9, 0, NULL, 0);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "unable to upload fpga firmware: "
 				"end urb.\n");
 		return ret;
 	}
 	return 0;
 }

 /* check, if the firmware version the devices has currently loaded
  * is known by this driver. 'version' needs to have 4 bytes version
  * info data. */
 static int usb6fire_fw_check(u8 *version)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(known_fw_versions); i++)
 		if (!memcmp(version, known_fw_versions + i, 4))
 			return 0;

 	snd_printk(KERN_ERR PREFIX "invalid fimware version in device: "
 			"%02x %02x %02x %02x. "
 			"please reconnect to power. if this failure "
 			"still happens, check your firmware installation.",
 			version[0], version[1], version[2], version[3]);
 	return -EINVAL;
 }

 int usb6fire_fw_init(struct usb_interface *intf)
 {
 	int i;
 	int ret;
 	struct usb_device *device = interface_to_usbdev(intf);
 	/* buffer: 8 receiving bytes from device and
 	 * sizeof(EP_W_MAX_PACKET_SIZE) bytes for non-const copy */
 	u8 buffer[12];

 	ret = usb6fire_fw_ezusb_read(device, 1, 0, buffer, 8);
 	if (ret < 0) {
 		snd_printk(KERN_ERR PREFIX "unable to receive device "
 				"firmware state.\n");
 		return ret;
 	}
 	if (buffer[0] != 0xeb || buffer[1] != 0xaa || buffer[2] != 0x55) {
 		snd_printk(KERN_ERR PREFIX "unknown device firmware state "
 				"received from device: ");
 		for (i = 0; i < 8; i++)
 			snd_printk("%02x ", buffer[i]);
 		snd_printk("\n");
 		return -EIO;
 	}
 	/* do we need fpga loader ezusb firmware? */
 	if (buffer[3] == 0x01) {
 		ret = usb6fire_fw_ezusb_upload(intf,
 				"6fire/dmx6firel2.ihx", 0, NULL, 0);
 		if (ret < 0)
 			return ret;
 		return FW_NOT_READY;
 	}
 	/* do we need fpga firmware and application ezusb firmware? */
 	else if (buffer[3] == 0x02) {
 		ret = usb6fire_fw_check(buffer + 4);
 		if (ret < 0)
 			return ret;
 		ret = usb6fire_fw_fpga_upload(intf, "6fire/dmx6firecf.bin");
 		if (ret < 0)
 			return ret;
 		memcpy(buffer, ep_w_max_packet_size,
 				sizeof(ep_w_max_packet_size));
 		ret = usb6fire_fw_ezusb_upload(intf, "6fire/dmx6fireap.ihx",
 				0x0003,	buffer, sizeof(ep_w_max_packet_size));
 		if (ret < 0)
 			return ret;
 		return FW_NOT_READY;
 	}
 	/* all fw loaded? */
 	else if (buffer[3] == 0x03)
 		return usb6fire_fw_check(buffer + 4);
 	/* unknown data? */
 	else {
 		snd_printk(KERN_ERR PREFIX "unknown device firmware state "
 				"received from device: ");
 		for (i = 0; i < 8; i++)
 			snd_printk("%02x ", buffer[i]);
 		snd_printk("\n");
 		return -EIO;
 	}
 	return 0;
 }
	/*
	* Linux driver for TerraTec DMX 6Fire USB
	*
	* Firmware loader
	*
	* Author: Torsten Schenk <torsten.schenk@zoho.com>
	* Created: Jan 01, 2011
	* Version: 0.3.0
	* Copyright: (C) Torsten Schenk
	*
	* 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.
	*/

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

	#include "firmware.h"
	#include "chip.h"

	MODULE_FIRMWARE("6fire/dmx6firel2.ihx");
	MODULE_FIRMWARE("6fire/dmx6fireap.ihx");
	MODULE_FIRMWARE("6fire/dmx6firecf.bin");

	enum {
	FPGA_BUFSIZE = 512, FPGA_EP = 2
	};

	/*
	* wMaxPacketSize of pcm endpoints.
	* keep synced with rates_in_packet_size and rates_out_packet_size in pcm.c
	* fpp: frames per isopacket
	*
	* CAUTION: keep sizeof <= buffer[] in usb6fire_fw_init
	*/
	static const u8 ep_w_max_packet_size[] = {
	0xe4, 0x00, 0xe4, 0x00, /* alt 1: 228 EP2 and EP6 (7 fpp) */
	0xa4, 0x01, 0xa4, 0x01, /* alt 2: 420 EP2 and EP6 (13 fpp)*/
	0x94, 0x01, 0x5c, 0x02 /* alt 3: 404 EP2 and 604 EP6 (25 fpp) */
	};

	static const u8 known_fw_versions[][4] = {
	{ 0x03, 0x01, 0x0b, 0x00 }
	};

	struct ihex_record {
	u16 address;
	u8 len;
	u8 data[256];
	char error; /* true if an error occurred parsing this record */

	u8 max_len; /* maximum record length in whole ihex */

	/* private */
	const char *txt_data;
	unsigned int txt_length;
	unsigned int txt_offset; /* current position in txt_data */
	};

	static u8 usb6fire_fw_ihex_nibble(const u8 n)
	{
	if (n >= '0' && n <= '9')
	return n - '0';
	else if (n >= 'A' && n <= 'F')
	return n - ('A' - 10);
	else if (n >= 'a' && n <= 'f')
	return n - ('a' - 10);
	return 0;
	}

	static u8 usb6fire_fw_ihex_hex(const u8 data, u8 crc)
	{
	u8 val = (usb6fire_fw_ihex_nibble(data[0]) << 4) \|
	usb6fire_fw_ihex_nibble(data[1]);
	*crc += val;
	return val;
	}

	/*
	* returns true if record is available, false otherwise.
	* iff an error occurred, false will be returned and record->error will be true.
	*/
	static bool usb6fire_fw_ihex_next_record(struct ihex_record *record)
	{
	u8 crc = 0;
	u8 type;
	int i;

	record->error = false;

	/* find begin of record (marked by a colon) */
	while (record->txt_offset < record->txt_length
	&& record->txt_data[record->txt_offset] != ':')
	record->txt_offset++;
	if (record->txt_offset == record->txt_length)
	return false;

	/* number of characters needed for len, addr and type entries */
	record->txt_offset++;
	if (record->txt_offset + 8 > record->txt_length) {
	record->error = true;
	return false;
	}

	record->len = usb6fire_fw_ihex_hex(record->txt_data +
	record->txt_offset, &crc);
	record->txt_offset += 2;
	record->address = usb6fire_fw_ihex_hex(record->txt_data +
	record->txt_offset, &crc) << 8;
	record->txt_offset += 2;
	record->address \|= usb6fire_fw_ihex_hex(record->txt_data +
	record->txt_offset, &crc);
	record->txt_offset += 2;
	type = usb6fire_fw_ihex_hex(record->txt_data +
	record->txt_offset, &crc);
	record->txt_offset += 2;

	/* number of characters needed for data and crc entries */
	if (record->txt_offset + 2 * (record->len + 1) > record->txt_length) {
	record->error = true;
	return false;
	}
	for (i = 0; i < record->len; i++) {
	record->data[i] = usb6fire_fw_ihex_hex(record->txt_data
	+ record->txt_offset, &crc);
	record->txt_offset += 2;
	}
	usb6fire_fw_ihex_hex(record->txt_data + record->txt_offset, &crc);
	if (crc) {
	record->error = true;
	return false;
	}

	if (type == 1 \|\| !record->len) /* eof */
	return false;
	else if (type == 0)
	return true;
	else {
	record->error = true;
	return false;
	}
	}

	static int usb6fire_fw_ihex_init(const struct firmware *fw,
	struct ihex_record *record)
	{
	record->txt_data = fw->data;
	record->txt_length = fw->size;
	record->txt_offset = 0;
	record->max_len = 0;
	/* read all records, if loop ends, record->error indicates,
	* whether ihex is valid. */
	while (usb6fire_fw_ihex_next_record(record))
	record->max_len = max(record->len, record->max_len);
	if (record->error)
	return -EINVAL;
	record->txt_offset = 0;
	return 0;
	}

	static int usb6fire_fw_ezusb_write(struct usb_device *device,
	int type, int value, char *data, int len)
	{
	int ret;

	ret = usb_control_msg(device, usb_sndctrlpipe(device, 0), type,
	USB_DIR_OUT \| USB_TYPE_VENDOR \| USB_RECIP_DEVICE,
	value, 0, data, len, HZ);
	if (ret < 0)
	return ret;
	else if (ret != len)
	return -EIO;
	return 0;
	}

	static int usb6fire_fw_ezusb_read(struct usb_device *device,
	int type, int value, char *data, int len)
	{
	int ret = usb_control_msg(device, usb_rcvctrlpipe(device, 0), type,
	USB_DIR_IN \| USB_TYPE_VENDOR \| USB_RECIP_DEVICE, value,
	0, data, len, HZ);
	if (ret < 0)
	return ret;
	else if (ret != len)
	return -EIO;
	return 0;
	}

	static int usb6fire_fw_fpga_write(struct usb_device *device,
	char *data, int len)
	{
	int actual_len;
	int ret;

	ret = usb_bulk_msg(device, usb_sndbulkpipe(device, FPGA_EP), data, len,
	&actual_len, HZ);
	if (ret < 0)
	return ret;
	else if (actual_len != len)
	return -EIO;
	return 0;
	}

	static int usb6fire_fw_ezusb_upload(
	struct usb_interface intf, const char fwname,
	unsigned int postaddr, u8 *postdata, unsigned int postlen)
	{
	int ret;
	u8 data;
	struct usb_device *device = interface_to_usbdev(intf);
	const struct firmware *fw = 0;
	struct ihex_record *rec = kmalloc(sizeof(struct ihex_record),
	GFP_KERNEL);

	if (!rec)
	return -ENOMEM;

	ret = request_firmware(&fw, fwname, &device->dev);
	if (ret < 0) {
	kfree(rec);
	snd_printk(KERN_ERR PREFIX "error requesting ezusb "
	"firmware %s.\n", fwname);
	return ret;
	}
	ret = usb6fire_fw_ihex_init(fw, rec);
	if (ret < 0) {
	kfree(rec);
	release_firmware(fw);
	snd_printk(KERN_ERR PREFIX "error validating ezusb "
	"firmware %s.\n", fwname);
	return ret;
	}
	/* upload firmware image */
	data = 0x01; /* stop ezusb cpu */
	ret = usb6fire_fw_ezusb_write(device, 0xa0, 0xe600, &data, 1);
	if (ret < 0) {
	kfree(rec);
	release_firmware(fw);
	snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
	"firmware %s: begin message.\n", fwname);
	return ret;
	}

	while (usb6fire_fw_ihex_next_record(rec)) { /* write firmware */
	ret = usb6fire_fw_ezusb_write(device, 0xa0, rec->address,
	rec->data, rec->len);
	if (ret < 0) {
	kfree(rec);
	release_firmware(fw);
	snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
	"firmware %s: data urb.\n", fwname);
	return ret;
	}
	}

	release_firmware(fw);
	kfree(rec);
	if (postdata) { /* write data after firmware has been uploaded */
	ret = usb6fire_fw_ezusb_write(device, 0xa0, postaddr,
	postdata, postlen);
	if (ret < 0) {
	snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
	"firmware %s: post urb.\n", fwname);
	return ret;
	}
	}

	data = 0x00; /* resume ezusb cpu */
	ret = usb6fire_fw_ezusb_write(device, 0xa0, 0xe600, &data, 1);
	if (ret < 0) {
	snd_printk(KERN_ERR PREFIX "unable to upload ezusb "
	"firmware %s: end message.\n", fwname);
	return ret;
	}
	return 0;
	}

	static int usb6fire_fw_fpga_upload(
	struct usb_interface intf, const char fwname)
	{
	int ret;
	int i;
	struct usb_device *device = interface_to_usbdev(intf);
	u8 *buffer = kmalloc(FPGA_BUFSIZE, GFP_KERNEL);
	const char *c;
	const char *end;
	const struct firmware *fw;

	if (!buffer)
	return -ENOMEM;

	ret = request_firmware(&fw, fwname, &device->dev);
	if (ret < 0) {
	snd_printk(KERN_ERR PREFIX "unable to get fpga firmware %s.\n",
	fwname);
	kfree(buffer);
	return -EIO;
	}

	c = fw->data;
	end = fw->data + fw->size;

	ret = usb6fire_fw_ezusb_write(device, 8, 0, NULL, 0);
	if (ret < 0) {
	kfree(buffer);
	release_firmware(fw);
	snd_printk(KERN_ERR PREFIX "unable to upload fpga firmware: "
	"begin urb.\n");
	return ret;
	}

	while (c != end) {
	for (i = 0; c != end && i < FPGA_BUFSIZE; i++, c++)
	buffer[i] = byte_rev_table[(u8) *c];

	ret = usb6fire_fw_fpga_write(device, buffer, i);
	if (ret < 0) {
	release_firmware(fw);
	kfree(buffer);
	snd_printk(KERN_ERR PREFIX "unable to upload fpga "
	"firmware: fw urb.\n");
	return ret;
	}
	}
	release_firmware(fw);
	kfree(buffer);

	ret = usb6fire_fw_ezusb_write(device, 9, 0, NULL, 0);
	if (ret < 0) {
	snd_printk(KERN_ERR PREFIX "unable to upload fpga firmware: "
	"end urb.\n");
	return ret;
	}
	return 0;
	}

	/* check, if the firmware version the devices has currently loaded
	* is known by this driver. 'version' needs to have 4 bytes version
	* info data. */
	static int usb6fire_fw_check(u8 *version)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(known_fw_versions); i++)
	if (!memcmp(version, known_fw_versions + i, 4))
	return 0;

	snd_printk(KERN_ERR PREFIX "invalid fimware version in device: "
	"%02x %02x %02x %02x. "
	"please reconnect to power. if this failure "
	"still happens, check your firmware installation.",
	version[0], version[1], version[2], version[3]);
	return -EINVAL;
	}

	int usb6fire_fw_init(struct usb_interface *intf)
	{
	int i;
	int ret;
	struct usb_device *device = interface_to_usbdev(intf);
	/* buffer: 8 receiving bytes from device and
	* sizeof(EP_W_MAX_PACKET_SIZE) bytes for non-const copy */
	u8 buffer[12];

	ret = usb6fire_fw_ezusb_read(device, 1, 0, buffer, 8);
	if (ret < 0) {
	snd_printk(KERN_ERR PREFIX "unable to receive device "
	"firmware state.\n");
	return ret;
	}
	if (buffer[0] != 0xeb \|\| buffer[1] != 0xaa \|\| buffer[2] != 0x55) {
	snd_printk(KERN_ERR PREFIX "unknown device firmware state "
	"received from device: ");
	for (i = 0; i < 8; i++)
	snd_printk("%02x ", buffer[i]);
	snd_printk("\n");
	return -EIO;
	}
	/* do we need fpga loader ezusb firmware? */
	if (buffer[3] == 0x01) {
	ret = usb6fire_fw_ezusb_upload(intf,
	"6fire/dmx6firel2.ihx", 0, NULL, 0);
	if (ret < 0)
	return ret;
	return FW_NOT_READY;
	}
	/* do we need fpga firmware and application ezusb firmware? */
	else if (buffer[3] == 0x02) {
	ret = usb6fire_fw_check(buffer + 4);
	if (ret < 0)
	return ret;
	ret = usb6fire_fw_fpga_upload(intf, "6fire/dmx6firecf.bin");
	if (ret < 0)
	return ret;
	memcpy(buffer, ep_w_max_packet_size,
	sizeof(ep_w_max_packet_size));
	ret = usb6fire_fw_ezusb_upload(intf, "6fire/dmx6fireap.ihx",
	0x0003, buffer, sizeof(ep_w_max_packet_size));
	if (ret < 0)
	return ret;
	return FW_NOT_READY;
	}
	/* all fw loaded? */
	else if (buffer[3] == 0x03)
	return usb6fire_fw_check(buffer + 4);
	/* unknown data? */
	else {
	snd_printk(KERN_ERR PREFIX "unknown device firmware state "
	"received from device: ");
	for (i = 0; i < 8; i++)
	snd_printk("%02x ", buffer[i]);
	snd_printk("\n");
	return -EIO;
	}
	return 0;
	}