text: /*
   *  drivers/media/radio/si470x/radio-si470x-usb.c
   *
   *  USB driver for radios with Silicon Labs Si470x FM Radio Receivers
   *
   *  Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net>
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  
  /*
   * ToDo:
   * - add firmware download/update support
   */
  
  
  /* driver definitions */
  #define DRIVER_AUTHOR "Tobias Lorenz <tobias.lorenz@gmx.net>"
  #define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
  #define DRIVER_DESC "USB radio driver for Si470x FM Radio Receivers"
  #define DRIVER_VERSION "1.0.10"
  
  /* kernel includes */
  #include <linux/usb.h>
  #include <linux/hid.h>
  #include <linux/slab.h>
  
  #include "radio-si470x.h"
  
  
  /* USB Device ID List */
  static struct usb_device_id si470x_usb_driver_id_table[] = {
  	/* Silicon Labs USB FM Radio Reference Design */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x10c4, 0x818a, USB_CLASS_HID, 0, 0) },
  	/* ADS/Tech FM Radio Receiver (formerly Instant FM Music) */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x06e1, 0xa155, USB_CLASS_HID, 0, 0) },
  	/* KWorld USB FM Radio SnapMusic Mobile 700 (FM700) */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x1b80, 0xd700, USB_CLASS_HID, 0, 0) },
  	/* Sanei Electric, Inc. FM USB Radio (sold as DealExtreme.com PCear) */
  	{ USB_DEVICE_AND_INTERFACE_INFO(0x10c5, 0x819a, USB_CLASS_HID, 0, 0) },
  	/* Terminating entry */
  	{ }
  };
  MODULE_DEVICE_TABLE(usb, si470x_usb_driver_id_table);
  
  
  
  /**************************************************************************
   * Module Parameters
   **************************************************************************/
  
  /* Radio Nr */
  static int radio_nr = -1;
  module_param(radio_nr, int, 0444);
  MODULE_PARM_DESC(radio_nr, "Radio Nr");
  
  /* USB timeout */
  static unsigned int usb_timeout = 500;
  module_param(usb_timeout, uint, 0644);
  MODULE_PARM_DESC(usb_timeout, "USB timeout (ms): *500*");
  
  /* RDS buffer blocks */
  static unsigned int rds_buf = 100;
  module_param(rds_buf, uint, 0444);
  MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
  
  /* RDS maximum block errors */
  static unsigned short max_rds_errors = 1;
  /* 0 means   0  errors requiring correction */
  /* 1 means 1-2  errors requiring correction (used by original USBRadio.exe) */
  /* 2 means 3-5  errors requiring correction */
  /* 3 means   6+ errors or errors in checkword, correction not possible */
  module_param(max_rds_errors, ushort, 0644);
  MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
  
  
  
  /**************************************************************************
   * USB HID Reports
   **************************************************************************/
  
  /* Reports 1-16 give direct read/write access to the 16 Si470x registers */
  /* with the (REPORT_ID - 1) corresponding to the register address across USB */
  /* endpoint 0 using GET_REPORT and SET_REPORT */
  #define REGISTER_REPORT_SIZE	(RADIO_REGISTER_SIZE + 1)
  #define REGISTER_REPORT(reg)	((reg) + 1)
  
  /* Report 17 gives direct read/write access to the entire Si470x register */
  /* map across endpoint 0 using GET_REPORT and SET_REPORT */
  #define ENTIRE_REPORT_SIZE	(RADIO_REGISTER_NUM * RADIO_REGISTER_SIZE + 1)
  #define ENTIRE_REPORT		17
  
  /* Report 18 is used to send the lowest 6 Si470x registers up the HID */
  /* interrupt endpoint 1 to Windows every 20 milliseconds for status */
  #define RDS_REPORT_SIZE		(RDS_REGISTER_NUM * RADIO_REGISTER_SIZE + 1)
  #define RDS_REPORT		18
  
  /* Report 19: LED state */
  #define LED_REPORT_SIZE		3
  #define LED_REPORT		19
  
  /* Report 19: stream */
  #define STREAM_REPORT_SIZE	3
  #define STREAM_REPORT		19
  
  /* Report 20: scratch */
  #define SCRATCH_PAGE_SIZE	63
  #define SCRATCH_REPORT_SIZE	(SCRATCH_PAGE_SIZE + 1)
  #define SCRATCH_REPORT		20
  
  /* Reports 19-22: flash upgrade of the C8051F321 */
  #define WRITE_REPORT_SIZE	4
  #define WRITE_REPORT		19
  #define FLASH_REPORT_SIZE	64
  #define FLASH_REPORT		20
  #define CRC_REPORT_SIZE		3
  #define CRC_REPORT		21
  #define RESPONSE_REPORT_SIZE	2
  #define RESPONSE_REPORT		22
  
  /* Report 23: currently unused, but can accept 60 byte reports on the HID */
  /* interrupt out endpoint 2 every 1 millisecond */
  #define UNUSED_REPORT		23
  
  
  
  /**************************************************************************
   * Software/Hardware Versions from Scratch Page
   **************************************************************************/
  #define RADIO_SW_VERSION_NOT_BOOTLOADABLE	6
  #define RADIO_SW_VERSION			7
  #define RADIO_HW_VERSION			1
  
  
  
  /**************************************************************************
   * LED State Definitions
   **************************************************************************/
  #define LED_COMMAND		0x35
  
  #define NO_CHANGE_LED		0x00
  #define ALL_COLOR_LED		0x01	/* streaming state */
  #define BLINK_GREEN_LED		0x02	/* connect state */
  #define BLINK_RED_LED		0x04
  #define BLINK_ORANGE_LED	0x10	/* disconnect state */
  #define SOLID_GREEN_LED		0x20	/* tuning/seeking state */
  #define SOLID_RED_LED		0x40	/* bootload state */
  #define SOLID_ORANGE_LED	0x80
  
  
  
  /**************************************************************************
   * Stream State Definitions
   **************************************************************************/
  #define STREAM_COMMAND	0x36
  #define STREAM_VIDPID	0x00
  #define STREAM_AUDIO	0xff
  
  
  
  /**************************************************************************
   * Bootloader / Flash Commands
   **************************************************************************/
  
  /* unique id sent to bootloader and required to put into a bootload state */
  #define UNIQUE_BL_ID		0x34
  
  /* mask for the flash data */
  #define FLASH_DATA_MASK		0x55
  
  /* bootloader commands */
  #define GET_SW_VERSION_COMMAND	0x00
  #define SET_PAGE_COMMAND	0x01
  #define ERASE_PAGE_COMMAND	0x02
  #define WRITE_PAGE_COMMAND	0x03
  #define CRC_ON_PAGE_COMMAND	0x04
  #define READ_FLASH_BYTE_COMMAND	0x05
  #define RESET_DEVICE_COMMAND	0x06
  #define GET_HW_VERSION_COMMAND	0x07
  #define BLANK			0xff
  
  /* bootloader command responses */
  #define COMMAND_OK		0x01
  #define COMMAND_FAILED		0x02
  #define COMMAND_PENDING		0x03
  
  
  
  /**************************************************************************
   * General Driver Functions - REGISTER_REPORTs
   **************************************************************************/
  
  /*
   * si470x_get_report - receive a HID report
   */
  static int si470x_get_report(struct si470x_device *radio, void *buf, int size)
  {
  	unsigned char *report = (unsigned char *) buf;
  	int retval;
  
  	retval = usb_control_msg(radio->usbdev,
  		usb_rcvctrlpipe(radio->usbdev, 0),
  		HID_REQ_GET_REPORT,
  		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
  		report[0], 2,
  		buf, size, usb_timeout);
  
  	if (retval < 0)
  		dev_warn(&radio->intf->dev,
  			"si470x_get_report: usb_control_msg returned %d\n",
  			retval);
  	return retval;
  }
  
  
  /*
   * si470x_set_report - send a HID report
   */
  static int si470x_set_report(struct si470x_device *radio, void *buf, int size)
  {
  	unsigned char *report = (unsigned char *) buf;
  	int retval;
  
  	retval = usb_control_msg(radio->usbdev,
  		usb_sndctrlpipe(radio->usbdev, 0),
  		HID_REQ_SET_REPORT,
  		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
  		report[0], 2,
  		buf, size, usb_timeout);
  
  	if (retval < 0)
  		dev_warn(&radio->intf->dev,
  			"si470x_set_report: usb_control_msg returned %d\n",
  			retval);
  	return retval;
  }
  
  
  /*
   * si470x_get_register - read register
   */
  int si470x_get_register(struct si470x_device *radio, int regnr)
  {
  	unsigned char buf[REGISTER_REPORT_SIZE];
  	int retval;
  
  	buf[0] = REGISTER_REPORT(regnr);
  
  	retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));
  
  	if (retval >= 0)
  		radio->registers[regnr] = get_unaligned_be16(&buf[1]);
  
  	return (retval < 0) ? -EINVAL : 0;
  }
  
  
  /*
   * si470x_set_register - write register
   */
  int si470x_set_register(struct si470x_device *radio, int regnr)
  {
  	unsigned char buf[REGISTER_REPORT_SIZE];
  	int retval;
  
  	buf[0] = REGISTER_REPORT(regnr);
  	put_unaligned_be16(radio->registers[regnr], &buf[1]);
  
  	retval = si470x_set_report(radio, (void *) &buf, sizeof(buf));
  
  	return (retval < 0) ? -EINVAL : 0;
  }
  
  
  
  /**************************************************************************
   * General Driver Functions - ENTIRE_REPORT
   **************************************************************************/
  
  /*
   * si470x_get_all_registers - read entire registers
   */
  static int si470x_get_all_registers(struct si470x_device *radio)
  {
  	unsigned char buf[ENTIRE_REPORT_SIZE];
  	int retval;
  	unsigned char regnr;
  
  	buf[0] = ENTIRE_REPORT;
  
  	retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));
  
  	if (retval >= 0)
  		for (regnr = 0; regnr < RADIO_REGISTER_NUM; regnr++)
  			radio->registers[regnr] = get_unaligned_be16(
  				&buf[regnr * RADIO_REGISTER_SIZE + 1]);
  
  	return (retval < 0) ? -EINVAL : 0;
  }
  
  
  
  /**************************************************************************
   * General Driver Functions - LED_REPORT
   **************************************************************************/
  
  /*
   * si470x_set_led_state - sets the led state
   */
  static int si470x_set_led_state(struct si470x_device *radio,
  		unsigned char led_state)
  {
  	unsigned char buf[LED_REPORT_SIZE];
  	int retval;
  
  	buf[0] = LED_REPORT;
  	buf[1] = LED_COMMAND;
  	buf[2] = led_state;
  
  	retval = si470x_set_report(radio, (void *) &buf, sizeof(buf));
  
  	return (retval < 0) ? -EINVAL : 0;
  }
  
  
  
  /**************************************************************************
   * General Driver Functions - SCRATCH_REPORT
   **************************************************************************/
  
  /*
   * si470x_get_scratch_versions - gets the scratch page and version infos
   */
  static int si470x_get_scratch_page_versions(struct si470x_device *radio)
  {
  	unsigned char buf[SCRATCH_REPORT_SIZE];
  	int retval;
  
  	buf[0] = SCRATCH_REPORT;
  
  	retval = si470x_get_report(radio, (void *) &buf, sizeof(buf));
  
  	if (retval < 0)
  		dev_warn(&radio->intf->dev, "si470x_get_scratch: "
  			"si470x_get_report returned %d\n", retval);
  	else {
  		radio->software_version = buf[1];
  		radio->hardware_version = buf[2];
  	}
  
  	return (retval < 0) ? -EINVAL : 0;
  }
  
  
  
  /**************************************************************************
   * General Driver Functions - DISCONNECT_CHECK
   **************************************************************************/
  
  /*
   * si470x_disconnect_check - check whether radio disconnects
   */
  int si470x_disconnect_check(struct si470x_device *radio)
  {
  	if (radio->disconnected)
  		return -EIO;
  	else
  		return 0;
  }
  
  
  
  /**************************************************************************
   * RDS Driver Functions
   **************************************************************************/
  
  /*
   * si470x_int_in_callback - rds callback and processing function
   *
   * TODO: do we need to use mutex locks in some sections?
   */
  static void si470x_int_in_callback(struct urb *urb)
  {
  	struct si470x_device *radio = urb->context;
  	int retval;
  	unsigned char regnr;
  	unsigned char blocknum;
  	unsigned short bler; /* rds block errors */
  	unsigned short rds;
  	unsigned char tmpbuf[3];
  
  	if (urb->status) {
  		if (urb->status == -ENOENT ||
  				urb->status == -ECONNRESET ||
  				urb->status == -ESHUTDOWN) {
  			return;
  		} else {
  			dev_warn(&radio->intf->dev,
  			 "non-zero urb status (%d)\n", urb->status);
  			goto resubmit; /* Maybe we can recover. */
  		}
  	}
  
  	/* safety checks */
  	if (radio->disconnected)
  		return;
  	if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
  		goto resubmit;
  
  	if (urb->actual_length > 0) {
  		/* Update RDS registers with URB data */
  		for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++)
  			radio->registers[STATUSRSSI + regnr] =
  			    get_unaligned_be16(&radio->int_in_buffer[
  				regnr * RADIO_REGISTER_SIZE + 1]);
  		/* get rds blocks */
  		if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0) {
  			/* No RDS group ready, better luck next time */
  			goto resubmit;
  		}
  		if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSS) == 0) {
  			/* RDS decoder not synchronized */
  			goto resubmit;
  		}
  		for (blocknum = 0; blocknum < 4; blocknum++) {
  			switch (blocknum) {
  			default:
  				bler = (radio->registers[STATUSRSSI] &
  						STATUSRSSI_BLERA) >> 9;
  				rds = radio->registers[RDSA];
  				break;
  			case 1:
  				bler = (radio->registers[READCHAN] &
  						READCHAN_BLERB) >> 14;
  				rds = radio->registers[RDSB];
  				break;
  			case 2:
  				bler = (radio->registers[READCHAN] &
  						READCHAN_BLERC) >> 12;
  				rds = radio->registers[RDSC];
  				break;
  			case 3:
  				bler = (radio->registers[READCHAN] &
  						READCHAN_BLERD) >> 10;
  				rds = radio->registers[RDSD];
  				break;
  			};
  
  			/* Fill the V4L2 RDS buffer */
  			put_unaligned_le16(rds, &tmpbuf);
  			tmpbuf[2] = blocknum;		/* offset name */
  			tmpbuf[2] |= blocknum << 3;	/* received offset */
  			if (bler > max_rds_errors)
  				tmpbuf[2] |= 0x80; /* uncorrectable errors */
  			else if (bler > 0)
  				tmpbuf[2] |= 0x40; /* corrected error(s) */
  
  			/* copy RDS block to internal buffer */
  			memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
  			radio->wr_index += 3;
  
  			/* wrap write pointer */
  			if (radio->wr_index >= radio->buf_size)
  				radio->wr_index = 0;
  
  			/* check for overflow */
  			if (radio->wr_index == radio->rd_index) {
  				/* increment and wrap read pointer */
  				radio->rd_index += 3;
  				if (radio->rd_index >= radio->buf_size)
  					radio->rd_index = 0;
  			}
  		}
  		if (radio->wr_index != radio->rd_index)
  			wake_up_interruptible(&radio->read_queue);
  	}
  
  resubmit:
  	/* Resubmit if we're still running. */
  	if (radio->int_in_running && radio->usbdev) {
  		retval = usb_submit_urb(radio->int_in_urb, GFP_ATOMIC);
  		if (retval) {
  			dev_warn(&radio->intf->dev,
  			       "resubmitting urb failed (%d)", retval);
  			radio->int_in_running = 0;
  		}
  	}
  }
  
  
  
  /**************************************************************************
   * File Operations Interface
   **************************************************************************/
  
  /*
   * si470x_fops_open - file open
   */
  int si470x_fops_open(struct file *file)
  {
  	struct si470x_device *radio = video_drvdata(file);
  	int retval;
  
  	mutex_lock(&radio->lock);
  	radio->users++;
  
  	retval = usb_autopm_get_interface(radio->intf);
  	if (retval < 0) {
  		radio->users--;
  		retval = -EIO;
  		goto done;
  	}
  
  	if (radio->users == 1) {
  		/* start radio */
  		retval = si470x_start(radio);
  		if (retval < 0) {
  			usb_autopm_put_interface(radio->intf);
  			goto done;
  		}
  
  		/* initialize interrupt urb */
  		usb_fill_int_urb(radio->int_in_urb, radio->usbdev,
  			usb_rcvintpipe(radio->usbdev,
  			radio->int_in_endpoint->bEndpointAddress),
  			radio->int_in_buffer,
  			le16_to_cpu(radio->int_in_endpoint->wMaxPacketSize),
  			si470x_int_in_callback,
  			radio,
  			radio->int_in_endpoint->bInterval);
  
  		radio->int_in_running = 1;
  		mb();
  
  		retval = usb_submit_urb(radio->int_in_urb, GFP_KERNEL);
  		if (retval) {
  			dev_info(&radio->intf->dev,
  				 "submitting int urb failed (%d)\n", retval);
  			radio->int_in_running = 0;
  			usb_autopm_put_interface(radio->intf);
  		}
  	}
  
  done:
  	mutex_unlock(&radio->lock);
  	return retval;
  }
  
  
  /*
   * si470x_fops_release - file release
   */
  int si470x_fops_release(struct file *file)
  {
  	struct si470x_device *radio = video_drvdata(file);
  	int retval = 0;
  
  	/* safety check */
  	if (!radio) {
  		retval = -ENODEV;
  		goto done;
  	}
  
  	mutex_lock(&radio->lock);
  	radio->users--;
  	if (radio->users == 0) {
  		/* shutdown interrupt handler */
  		if (radio->int_in_running) {
  			radio->int_in_running = 0;
  		if (radio->int_in_urb)
  			usb_kill_urb(radio->int_in_urb);
  		}
  
  		if (radio->disconnected) {
  			video_unregister_device(radio->videodev);
  			kfree(radio->int_in_buffer);
  			kfree(radio->buffer);
  			mutex_unlock(&radio->lock);
  			kfree(radio);
  			goto done;
  		}
  
  		/* cancel read processes */
  		wake_up_interruptible(&radio->read_queue);
  
  		/* stop radio */
  		retval = si470x_stop(radio);
  		usb_autopm_put_interface(radio->intf);
  	}
  	mutex_unlock(&radio->lock);
  done:
  	return retval;
  }
  
  
  
  /**************************************************************************
   * Video4Linux Interface
   **************************************************************************/
  
  /*
   * si470x_vidioc_querycap - query device capabilities
   */
  int si470x_vidioc_querycap(struct file *file, void *priv,
  		struct v4l2_capability *capability)
  {
  	struct si470x_device *radio = video_drvdata(file);
  
  	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
  	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
  	usb_make_path(radio->usbdev, capability->bus_info,
  			sizeof(capability->bus_info));
  	capability->capabilities = V4L2_CAP_HW_FREQ_SEEK |
  		V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
  
  	return 0;
  }
  
  
  
  /**************************************************************************
   * USB Interface
   **************************************************************************/
  
  /*
   * si470x_usb_driver_probe - probe for the device
   */
  static int si470x_usb_driver_probe(struct usb_interface *intf,
  		const struct usb_device_id *id)
  {
  	struct si470x_device *radio;
  	struct usb_host_interface *iface_desc;
  	struct usb_endpoint_descriptor *endpoint;
  	int i, int_end_size, retval = 0;
  	unsigned char version_warning = 0;
  
  	/* private data allocation and initialization */
  	radio = kzalloc(sizeof(struct si470x_device), GFP_KERNEL);
  	if (!radio) {
  		retval = -ENOMEM;
  		goto err_initial;
  	}
  	radio->users = 0;
  	radio->disconnected = 0;
  	radio->usbdev = interface_to_usbdev(intf);
  	radio->intf = intf;
  	mutex_init(&radio->lock);
  
  	iface_desc = intf->cur_altsetting;
  
  	/* Set up interrupt endpoint information. */
  	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
  		endpoint = &iface_desc->endpoint[i].desc;
  		if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) ==
  		 USB_DIR_IN) && ((endpoint->bmAttributes &
  		 USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT))
  			radio->int_in_endpoint = endpoint;
  	}
  	if (!radio->int_in_endpoint) {
  		dev_info(&intf->dev, "could not find interrupt in endpoint\n");
  		retval = -EIO;
  		goto err_radio;
  	}
  
  	int_end_size = le16_to_cpu(radio->int_in_endpoint->wMaxPacketSize);
  
  	radio->int_in_buffer = kmalloc(int_end_size, GFP_KERNEL);
  	if (!radio->int_in_buffer) {
  		dev_info(&intf->dev, "could not allocate int_in_buffer");
  		retval = -ENOMEM;
  		goto err_radio;
  	}
  
  	radio->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
  	if (!radio->int_in_urb) {
  		dev_info(&intf->dev, "could not allocate int_in_urb");
  		retval = -ENOMEM;
  		goto err_intbuffer;
  	}
  
  	/* video device allocation and initialization */
  	radio->videodev = video_device_alloc();
  	if (!radio->videodev) {
  		retval = -ENOMEM;
  		goto err_urb;
  	}
  	memcpy(radio->videodev, &si470x_viddev_template,
  			sizeof(si470x_viddev_template));
  	video_set_drvdata(radio->videodev, radio);
  
  	/* get device and chip versions */
  	if (si470x_get_all_registers(radio) < 0) {
  		retval = -EIO;
  		goto err_video;
  	}
  	dev_info(&intf->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
  			radio->registers[DEVICEID], radio->registers[CHIPID]);
  	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
  		dev_warn(&intf->dev,
  			"This driver is known to work with "
  			"firmware version %hu,\n", RADIO_FW_VERSION);
  		dev_warn(&intf->dev,
  			"but the device has firmware version %hu.\n",
  			radio->registers[CHIPID] & CHIPID_FIRMWARE);
  		version_warning = 1;
  	}
  
  	/* get software and hardware versions */
  	if (si470x_get_scratch_page_versions(radio) < 0) {
  		retval = -EIO;
  		goto err_video;
  	}
  	dev_info(&intf->dev, "software version %d, hardware version %d\n",
  			radio->software_version, radio->hardware_version);
  	if (radio->software_version < RADIO_SW_VERSION) {
  		dev_warn(&intf->dev,
  			"This driver is known to work with "
  			"software version %hu,\n", RADIO_SW_VERSION);
  		dev_warn(&intf->dev,
  			"but the device has software version %hu.\n",
  			radio->software_version);
  		version_warning = 1;
  	}
  	if (radio->hardware_version < RADIO_HW_VERSION) {
  		dev_warn(&intf->dev,
  			"This driver is known to work with "
  			"hardware version %hu,\n", RADIO_HW_VERSION);
  		dev_warn(&intf->dev,
  			"but the device has hardware version %hu.\n",
  			radio->hardware_version);
  		version_warning = 1;
  	}
  
  	/* give out version warning */
  	if (version_warning == 1) {
  		dev_warn(&intf->dev,
  			"If you have some trouble using this driver,\n");
  		dev_warn(&intf->dev,
  			"please report to V4L ML at "
  			"linux-media@vger.kernel.org\n");
  	}
  
  	/* set initial frequency */
  	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
  
  	/* set led to connect state */
  	si470x_set_led_state(radio, BLINK_GREEN_LED);
  
  	/* rds buffer allocation */
  	radio->buf_size = rds_buf * 3;
  	radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL);
  	if (!radio->buffer) {
  		retval = -EIO;
  		goto err_video;
  	}
  
  	/* rds buffer configuration */
  	radio->wr_index = 0;
  	radio->rd_index = 0;
  	init_waitqueue_head(&radio->read_queue);
  
  	/* register video device */
  	retval = video_register_device(radio->videodev, VFL_TYPE_RADIO,
  			radio_nr);
  	if (retval) {
  		dev_warn(&intf->dev, "Could not register video device\n");
  		goto err_all;
  	}
  	usb_set_intfdata(intf, radio);
  
  	return 0;
  err_all:
  	kfree(radio->buffer);
  err_video:
  	video_device_release(radio->videodev);
  err_urb:
  	usb_free_urb(radio->int_in_urb);
  err_intbuffer:
  	kfree(radio->int_in_buffer);
  err_radio:
  	kfree(radio);
  err_initial:
  	return retval;
  }
  
  
  /*
   * si470x_usb_driver_suspend - suspend the device
   */
  static int si470x_usb_driver_suspend(struct usb_interface *intf,
  		pm_message_t message)
  {
  	dev_info(&intf->dev, "suspending now...\n");
  
  	return 0;
  }
  
  
  /*
   * si470x_usb_driver_resume - resume the device
   */
  static int si470x_usb_driver_resume(struct usb_interface *intf)
  {
  	dev_info(&intf->dev, "resuming now...\n");
  
  	return 0;
  }
  
  
  /*
   * si470x_usb_driver_disconnect - disconnect the device
   */
  static void si470x_usb_driver_disconnect(struct usb_interface *intf)
  {
  	struct si470x_device *radio = usb_get_intfdata(intf);
  
  	mutex_lock(&radio->lock);
  	radio->disconnected = 1;
  	usb_set_intfdata(intf, NULL);
  	if (radio->users == 0) {
  		/* set led to disconnect state */
  		si470x_set_led_state(radio, BLINK_ORANGE_LED);
  
  		/* Free data structures. */
  		usb_free_urb(radio->int_in_urb);
  
  		kfree(radio->int_in_buffer);
  		video_unregister_device(radio->videodev);
  		kfree(radio->buffer);
  		mutex_unlock(&radio->lock);
  		kfree(radio);
  	} else {
  		mutex_unlock(&radio->lock);
  	}
  }
  
  
  /*
   * si470x_usb_driver - usb driver interface
   */
  static struct usb_driver si470x_usb_driver = {
  	.name			= DRIVER_NAME,
  	.probe			= si470x_usb_driver_probe,
  	.disconnect		= si470x_usb_driver_disconnect,
  	.suspend		= si470x_usb_driver_suspend,
  	.resume			= si470x_usb_driver_resume,
  	.id_table		= si470x_usb_driver_id_table,
  	.supports_autosuspend	= 1,
  };
  
  module_usb_driver(si470x_usb_driver);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR(DRIVER_AUTHOR);
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_VERSION(DRIVER_VERSION);
  