V4L/DVB (7038): USB radio driver for Silicon Labs Si470x FM Radio Receivers

this patch adds a new driver for the Silicon Labs Si470x FM Radio Receiver. It
should also work for the identical ADS/Tech FM Radio Receiver (formerly
Instant FM Music) as soon as I find out the USB Vendor and Product ID.

The driver is inspired by several other USB and radio drivers, but mainly from
the D-Link DSB-R100 USB radio (dsbr100.c).

The USB stick currently has an Si4701 FM RDS radio receiver. But the other
Si470x devices are pin and register compatible, so that in the future the
driver can easily be patched to support these too. Therefore I named the
driver radio-si470x and the configuration option usb-si470x.

The driver itself just provides the control function over the radio. For
getting audio back, the device support the USB audio class, which is
implemented in the already existing driver.

I tested the driver in the last days, until it now satisfies all my
functionality and robustness requirements. The application I used for testing
was kradio.

Signed-off-by: Tobias Lorenz <tobias.lorenz@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

3 files changed, 1451 insertions, 0 deletions

diff --git a/drivers/media/radio/Kconfig b/drivers/media/radio/Kconfig
index 11e962f..8d5214f 100644
--- a/drivers/media/radio/Kconfig
+++ b/drivers/media/radio/Kconfig
@@ -351,4 +351,14 @@ config USB_DSBR
 	  To compile this driver as a module, choose M here: the
 	  module will be called dsbr100.
 
+config USB_SI470X
+	tristate "Silicon Labs Si470x FM Radio Receiver support"
+	depends on USB && VIDEO_V4L2
+	---help---
+	  Say Y here if you want to connect this type of radio to your
+	  computer's USB port.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called radio-silabs.
+
 endif # RADIO_ADAPTERS
diff --git a/drivers/media/radio/Makefile b/drivers/media/radio/Makefile
index cf55a18..f36cf4e 100644
--- a/drivers/media/radio/Makefile
+++ b/drivers/media/radio/Makefile
@@ -21,5 +21,6 @@ obj-$(CONFIG_RADIO_GEMTEK_PCI) += radio-gemtek-pci.o
 obj-$(CONFIG_RADIO_TRUST) += radio-trust.o
 obj-$(CONFIG_RADIO_MAESTRO) += radio-maestro.o
 obj-$(CONFIG_USB_DSBR) += dsbr100.o
+obj-$(CONFIG_USB_SI470X) := radio-si470x.o
 
 EXTRA_CFLAGS += -Isound
diff --git a/drivers/media/radio/radio-si470x.c b/drivers/media/radio/radio-si470x.c
new file mode 100644
index 0000000..eccbc75
--- /dev/null
+++ b/drivers/media/radio/radio-si470x.c
@@ -0,0 +1,1440 @@
+/*
+ *  drivers/media/radio/radio-si470x.c
+ *
+ *  Driver for USB radios for the Silicon Labs Si470x FM Radio Receivers:
+ *   - Silicon Labs USB FM Radio Reference Design
+ *   - ADS/Tech FM Radio Receiver (formerly Instant FM Music) (RDX-155-EF)
+ *
+ *  Copyright (c) 2007 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
+ */
+
+
+/*
+ * History:
+ * 2008-01-12	Tobias Lorenz <tobias.lorenz@gmx.net>
+ *		Version 1.0.0
+ *		- First working version
+ * 2008-01-13   Tobias Lorenz <tobias.lorenz@gmx.net>
+ *              Version 1.0.1
+ *		- Improved error handling, every function now returns errno
+ *		- Improved multi user access (start/mute/stop)
+ *		- Channel doesn't get lost anymore after start/mute/stop
+ *		- RDS support added (polling mode via interrupt EP 1)
+ *		- marked default module parameters with *value*
+ *		- switched from bit structs to bit masks
+ *		- header file cleaned and integrated
+ * 2008-01-14	Tobias Lorenz <tobias.lorenz@gmx.net>
+ * 		Version 1.0.2
+ * 		- hex values are now lower case
+ * 		- commented USB ID for ADS/Tech moved on todo list
+ * 		- blacklisted si470x in hid-quirks.c
+ * 		- rds buffer handling functions integrated into *_work, *_read
+ * 		- rds_command in si470x_poll exchanged against simple retval
+ * 		- check for firmware version 15
+ * 		- code order and prototypes still remain the same
+ * 		- spacing and bottom of band codes remain the same
+ *
+ * ToDo:
+ * - check USB Vendor/Product ID for ADS/Tech FM Radio Receiver
+ *   (formerly Instant FM Music) (RDX-155-EF) is 06e1:a155
+ * - add seeking support
+ * - add firmware download/update support
+ * - add possibility to switch off RDS
+ * - RDS support: interrupt mode, instead of polling
+ * - add LED status output
+ */
+
+/* driver definitions */
+#define DRIVER_AUTHOR "Tobias Lorenz <tobias.lorenz@gmx.net>"
+#define DRIVER_NAME "radio-si470x"
+#define DRIVER_VERSION KERNEL_VERSION(1, 0, 2)
+#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
+#define DRIVER_DESC "USB radio driver for Si470x FM Radio Receivers"
+
+
+/* kernel includes */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-common.h>
+#include <linux/usb.h>
+#include <linux/hid.h>
+#include <linux/version.h>
+#include <media/rds.h>
+
+
+/* Radio Nr */
+static int radio_nr = -1;
+module_param(radio_nr, int, 0);
+MODULE_PARM_DESC(radio_nr, "Radio Nr");
+
+/* Spacing (kHz) */
+/* 0: 200 kHz (USA, Australia) */
+/* 1: 100 kHz (Europe, Japan) */
+/* 2:  50 kHz */
+static int space = 2;
+module_param(space, int, 0);
+MODULE_PARM_DESC(radio_nr, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");
+
+/* Bottom of Band (MHz) */
+/* 0: 87.5 - 108 MHz (USA, Europe)*/
+/* 1: 76   - 108 MHz (Japan wide band) */
+/* 2: 76   -  90 MHz (Japan) */
+static int band = 1;
+module_param(band, int, 0);
+MODULE_PARM_DESC(radio_nr, "Band: 0=87.5..108MHz *1=76..108MHz* 2=76..90MHz");
+
+/* De-emphasis */
+/* 0: 75 us (USA) */
+/* 1: 50 us (Europe, Australia, Japan) */
+static int de = 1;
+module_param(de, int, 0);
+MODULE_PARM_DESC(radio_nr, "De-emphasis: 0=75us *1=50us*");
+
+/* USB timeout */
+static int usb_timeout = 500;
+module_param(usb_timeout, int, 0);
+MODULE_PARM_DESC(usb_timeout, "USB timeout (ms): *500*");
+
+/* Seek retries */
+static int seek_retries = 100;
+module_param(seek_retries, int, 0);
+MODULE_PARM_DESC(seek_retries, "Seek retries: *100*");
+
+/* RDS buffer blocks */
+static int rds_buf = 100;
+module_param(rds_buf, int, 0);
+MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
+
+/* RDS maximum block errors */
+static int 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, int, 0);
+MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
+
+/* RDS poll frequency */
+static int rds_poll_time = 40;
+/* 40 is used by the original USBRadio.exe */
+/* 75 should be okay */
+/* 80 is the usual RDS receive interval */
+module_param(rds_poll_time, int, 0);
+MODULE_PARM_DESC(rds_poll_time, "RDS poll time (ms): *40*");
+
+
+
+/**************************************************************************
+ * Register Definitions
+ **************************************************************************/
+#define FMRADIO_REGISTER_SIZE	2	/* 16 register bit width */
+#define FMRADIO_REGISTER_NUM	16	/* DEVICEID   ... RDSD */
+#define RDS_REGISTER_NUM	6	/* STATUSRSSI ... RDSD */
+
+#define DEVICEID		0	/* Device ID */
+#define DEVICEID_PN		0xf000	/* bits 15..12: Part Number */
+#define DEVICEID_MFGID		0x0fff	/* bits 11..00: Manufacturer ID */
+
+#define CHIPID			1	/* Chip ID */
+#define CHIPID_REV		0xfc00	/* bits 15..10: Chip Version */
+#define CHIPID_DEV		0x0200	/* bits 09..09: Device */
+#define CHIPID_FIRMWARE		0x01ff	/* bits 08..00: Firmware Version */
+
+#define POWERCFG		2	/* Power Configuration */
+#define POWERCFG_DSMUTE		0x8000	/* bits 15..15: Softmute Disable */
+#define POWERCFG_DMUTE		0x4000	/* bits 14..14: Mute Disable */
+#define POWERCFG_MONO		0x2000	/* bits 13..13: Mono Select */
+#define POWERCFG_RDSM		0x0800	/* bits 11..11: RDS Mode (Si4701 only) */
+#define POWERCFG_SKMODE		0x0400	/* bits 10..10: Seek Mode */
+#define POWERCFG_SEEKUP		0x0200	/* bits 09..09: Seek Direction */
+#define POWERCFG_SEEK		0x0100	/* bits 08..08: Seek */
+#define POWERCFG_DISABLE	0x0040	/* bits 06..06: Powerup Disable */
+#define POWERCFG_ENABLE		0x0001	/* bits 00..00: Powerup Enable */
+
+#define CHANNEL			3	/* Channel */
+#define CHANNEL_TUNE		0x8000	/* bits 15..15: Tune */
+#define CHANNEL_CHAN		0x03ff	/* bits 09..00: Channel Select */
+
+#define SYSCONFIG1		4	/* System Configuration 1 */
+#define SYSCONFIG1_RDSIEN	0x8000	/* bits 15..15: RDS Interrupt Enable (Si4701 only) */
+#define SYSCONFIG1_STCIEN	0x4000	/* bits 14..14: Seek/Tune Complete Interrupt Enable */
+#define SYSCONFIG1_RDS		0x1000	/* bits 12..12: RDS Enable (Si4701 only) */
+#define SYSCONFIG1_DE		0x0800	/* bits 11..11: De-emphasis (0=75us 1=50us) */
+#define SYSCONFIG1_AGCD		0x0400	/* bits 10..10: AGC Disable */
+#define SYSCONFIG1_BLNDADJ	0x00c0	/* bits 07..06: Stereo/Mono Blend Level Adjustment */
+#define SYSCONFIG1_GPIO3	0x0030	/* bits 05..04: General Purpose I/O 3 */
+#define SYSCONFIG1_GPIO2	0x000c	/* bits 03..02: General Purpose I/O 2 */
+#define SYSCONFIG1_GPIO1	0x0003	/* bits 01..00: General Purpose I/O 1 */
+
+#define SYSCONFIG2		5	/* System Configuration 2 */
+#define SYSCONFIG2_SEEKTH	0xff00	/* bits 15..08: RSSI Seek Threshold */
+#define SYSCONFIG2_BAND		0x0080	/* bits 07..06: Band Select */
+#define SYSCONFIG2_SPACE	0x0030	/* bits 05..04: Channel Spacing */
+#define SYSCONFIG2_VOLUME	0x000f	/* bits 03..00: Volume */
+
+#define SYSCONFIG3		6	/* System Configuration 3 */
+#define SYSCONFIG3_SMUTER	0xc000	/* bits 15..14: Softmute Attack/Recover Rate */
+#define SYSCONFIG3_SMUTEA	0x3000	/* bits 13..12: Softmute Attenuation */
+#define SYSCONFIG3_SKSNR	0x00f0	/* bits 07..04: Seek SNR Threshold */
+#define SYSCONFIG3_SKCNT	0x000f	/* bits 03..00: Seek FM Impulse Detection Threshold */
+
+#define TEST1			7	/* Test 1 */
+#define TEST1_AHIZEN		0x4000	/* bits 14..14: Audio High-Z Enable */
+
+#define TEST2			8	/* Test 2 */
+/* TEST2 only contains reserved bits */
+
+#define BOOTCONFIG		9	/* Boot Configuration */
+/* BOOTCONFIG only contains reserved bits */
+
+#define STATUSRSSI		10	/* Status RSSI */
+#define STATUSRSSI_RDSR		0x8000	/* bits 15..15: RDS Ready (Si4701 only) */
+#define STATUSRSSI_STC		0x4000	/* bits 14..14: Seek/Tune Complete */
+#define STATUSRSSI_SF		0x2000	/* bits 13..13: Seek Fail/Band Limit */
+#define STATUSRSSI_AFCRL	0x1000	/* bits 12..12: AFC Rail */
+#define STATUSRSSI_RDSS		0x0800	/* bits 11..11: RDS Synchronized (Si4701 only) */
+#define STATUSRSSI_BLERA	0x0600	/* bits 10..09: RDS Block A Errors (Si4701 only) */
+#define STATUSRSSI_ST		0x0100	/* bits 08..08: Stereo Indicator */
+#define STATUSRSSI_RSSI		0x00ff	/* bits 07..00: RSSI (Received Signal Strength Indicator) */
+
+#define READCHAN		11	/* Read Channel */
+#define READCHAN_BLERB		0xc000	/* bits 15..14: RDS Block D Errors (Si4701 only) */
+#define READCHAN_BLERC		0x3000	/* bits 13..12: RDS Block C Errors (Si4701 only) */
+#define READCHAN_BLERD		0x0c00	/* bits 11..10: RDS Block B Errors (Si4701 only) */
+#define READCHAN_READCHAN	0x03ff	/* bits 09..00: Read Channel */
+
+#define RDSA			12	/* RDSA */
+#define RDSA_RDSA		0xffff	/* bits 15..00: RDS Block A Data (Si4701 only) */
+
+#define RDSB			13	/* RDSB */
+#define RDSB_RDSB		0xffff	/* bits 15..00: RDS Block B Data (Si4701 only) */
+
+#define RDSC			14	/* RDSC */
+#define RDSC_RDSC		0xffff	/* bits 15..00: RDS Block C Data (Si4701 only) */
+
+#define RDSD			15	/* RDSD */
+#define RDSD_RDSD		0xffff	/* bits 15..00: RDS Block D Data (Si4701 only) */
+
+
+
+/**************************************************************************
+ * 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	(FMRADIO_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	(FMRADIO_REGISTER_NUM * FMRADIO_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 * FMRADIO_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		19
+#define FLASH_REPORT		20
+#define CRC_REPORT		21
+#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
+ **************************************************************************/
+#define FMRADIO_SW_VERSION_NOT_BOOTLOADABLE	6
+#define FMRADIO_SW_VERSION			7
+#define FMRADIO_SW_VERSION_CURRENT		15
+#define FMRADIO_HW_VERSION			1
+
+#define SCRATCH_PAGE_SW_VERSION	1
+#define SCRATCH_PAGE_HW_VERSION	2
+
+
+
+/**************************************************************************
+ * 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
+
+/* Buffer sizes */
+#define COMMAND_BUFFER_SIZE	4
+#define RESPONSE_BUFFER_SIZE	2
+#define FLASH_BUFFER_SIZE	64
+#define CRC_BUFFER_SIZE		3
+
+
+
+/**************************************************************************
+ * Driver private definitions
+ **************************************************************************/
+
+/* private data */
+struct si470x_device {
+	/* reference to USB and video device */
+	struct usb_device *usbdev;
+	struct video_device *videodev;
+
+	/* are these really necessary ? */
+	int users;
+
+	/* report buffer (maximum 64 bytes) */
+	unsigned char buf[64];
+
+	/* Silabs internal registers (0..15) */
+	unsigned short registers[FMRADIO_REGISTER_NUM];
+
+	/* RDS receive buffer */
+	struct work_struct work;
+	struct timer_list timer;
+	spinlock_t lock;
+	unsigned char *buffer;
+	unsigned int buf_size;
+	unsigned int rd_index;
+	unsigned int wr_index;
+	unsigned int block_count;
+	unsigned char last_blocknum;
+	wait_queue_head_t read_queue;
+	int data_available_for_read;
+};
+
+/* register acccess functions */
+static int si470x_get_report(struct si470x_device *radio, int size);
+static int si470x_set_report(struct si470x_device *radio, int size);
+static int si470x_get_register(struct si470x_device *radio, int regnr);
+static int si470x_set_register(struct si470x_device *radio, int regnr);
+static int si470x_get_all_registers(struct si470x_device *radio);
+static int si470x_get_rds_registers(struct si470x_device *radio);
+
+/* high-level functions */
+static int si470x_start(struct si470x_device *radio);
+static int si470x_stop(struct si470x_device *radio);
+static int si470x_set_chan(struct si470x_device *radio, int chan);
+static int si470x_get_freq(struct si470x_device *radio);
+static int si470x_set_freq(struct si470x_device *radio, int freq);
+
+/* RDS functions */
+static void si470x_rds(struct si470x_device *radio);
+static void si470x_timer(unsigned long data);
+static void si470x_work(struct work_struct *work);
+
+
+
+/**************************************************************************
+ * USB interface definitions
+ **************************************************************************/
+
+/* USB device ID list (Vendor, Product, Class, SubClass, Protocol) */
+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) },
+	/* Terminating entry */
+	{ }
+};
+MODULE_DEVICE_TABLE (usb, si470x_usb_driver_id_table);
+
+/* USB driver functions */
+static int si470x_usb_driver_probe(struct usb_interface *intf,
+		const struct usb_device_id *id);
+static void si470x_usb_driver_disconnect(struct usb_interface *intf);
+
+/* USB driver interface */
+static struct usb_driver si470x_usb_driver = {
+	.name		= DRIVER_NAME,
+	.probe		= si470x_usb_driver_probe,
+	.disconnect	= si470x_usb_driver_disconnect,
+	.id_table	= si470x_usb_driver_id_table,
+};
+
+
+
+/**************************************************************************
+ * Video4Linux interface definitions
+ **************************************************************************/
+
+/* The frequency is set in units of 62.5 Hz when using V4L2_TUNER_CAP_LOW, */
+/* 62.5 kHz otherwise. */
+/* The tuner is able to have a channel spacing of 50, 100 or 200 kHz. */
+/* tuner->capability is therefore set to V4L2_TUNER_CAP_LOW */
+/* The FREQ_MUL is then: 1 MHz / 62.5 Hz = 16000 */
+#define FREQ_MUL (1000000 / 62.5)
+
+/* File operations functions */
+static ssize_t si470x_fops_read(struct file *file, char __user *buf,
+		size_t count, loff_t *ppos);
+static unsigned int si470x_fops_poll(struct file *file,
+		struct poll_table_struct *pts);
+static int si470x_fops_open(struct inode *inode, struct file *file);
+static int si470x_fops_release(struct inode *inode, struct file *file);
+
+/* File operations interface */
+static const struct file_operations si470x_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.read		= si470x_fops_read,
+	.poll		= si470x_fops_poll,
+	.ioctl		= video_ioctl2,
+	.compat_ioctl	= v4l_compat_ioctl32,
+	.open		= si470x_fops_open,
+	.release	= si470x_fops_release,
+};
+
+/* Video device functions */
+static int si470x_vidioc_querycap(struct file *file, void *priv,
+		struct v4l2_capability *capability);
+static int si470x_vidioc_g_input(struct file *file, void *priv,
+		unsigned int *i);
+static int si470x_vidioc_s_input(struct file *file, void *priv,
+		unsigned int i);
+static int si470x_vidioc_queryctrl(struct file *file, void *priv,
+		struct v4l2_queryctrl *qc);
+static int si470x_vidioc_g_ctrl(struct file *file, void *priv,
+		struct v4l2_control *ctrl);
+static int si470x_vidioc_s_ctrl(struct file *file, void *priv,
+		struct v4l2_control *ctrl);
+static int si470x_vidioc_g_audio(struct file *file, void *priv,
+		struct v4l2_audio *audio);
+static int si470x_vidioc_s_audio(struct file *file, void *priv,
+		struct v4l2_audio *audio);
+static int si470x_vidioc_g_tuner(struct file *file, void *priv,
+		struct v4l2_tuner *tuner);
+static int si470x_vidioc_s_tuner(struct file *file, void *priv,
+		struct v4l2_tuner *tuner);
+static int si470x_vidioc_g_frequency(struct file *file, void *priv,
+		struct v4l2_frequency *freq);
+static int si470x_vidioc_s_frequency(struct file *file, void *priv,
+		struct v4l2_frequency *freq);
+
+/* Video device interface */
+static struct video_device si470x_viddev_template = {
+	.fops			= &si470x_fops,
+	.name			= DRIVER_NAME,
+	.type			= VID_TYPE_TUNER,
+	.release		= video_device_release,
+	.vidioc_querycap	= si470x_vidioc_querycap,
+	.vidioc_g_input		= si470x_vidioc_g_input,
+	.vidioc_s_input		= si470x_vidioc_s_input,
+	.vidioc_queryctrl	= si470x_vidioc_queryctrl,
+	.vidioc_g_ctrl		= si470x_vidioc_g_ctrl,
+	.vidioc_s_ctrl		= si470x_vidioc_s_ctrl,
+	.vidioc_g_audio		= si470x_vidioc_g_audio,
+	.vidioc_s_audio		= si470x_vidioc_s_audio,
+	.vidioc_g_tuner		= si470x_vidioc_g_tuner,
+	.vidioc_s_tuner		= si470x_vidioc_s_tuner,
+	.vidioc_g_frequency	= si470x_vidioc_g_frequency,
+	.vidioc_s_frequency	= si470x_vidioc_s_frequency,
+	.owner			= THIS_MODULE,
+};
+
+/* Query control */
+static struct v4l2_queryctrl radio_queryctrl[] = {
+/* HINT: the disabled controls are only here to satify kradio and such apps */
+	{
+		.id		= V4L2_CID_AUDIO_VOLUME,
+		.type		= V4L2_CTRL_TYPE_INTEGER,
+		.name		= "Volume",
+		.minimum	= 0,
+		.maximum	= 15,
+		.step		= 1,
+		.default_value	= 15,
+	},
+	{
+		.id		= V4L2_CID_AUDIO_BALANCE,
+		.flags		= V4L2_CTRL_FLAG_DISABLED,
+	},
+	{
+		.id		= V4L2_CID_AUDIO_BASS,
+		.flags		= V4L2_CTRL_FLAG_DISABLED,
+	},
+	{
+		.id		= V4L2_CID_AUDIO_TREBLE,
+		.flags		= V4L2_CTRL_FLAG_DISABLED,
+	},
+	{
+		.id		= V4L2_CID_AUDIO_MUTE,
+		.type		= V4L2_CTRL_TYPE_BOOLEAN,
+		.name		= "Mute",
+		.minimum	= 0,
+		.maximum	= 1,
+		.step		= 1,
+		.default_value	= 1,
+	},
+	{
+		.id		= V4L2_CID_AUDIO_LOUDNESS,
+		.flags		= V4L2_CTRL_FLAG_DISABLED,
+	},
+};
+
+
+
+/**************************************************************************
+ * Driver private functions
+ **************************************************************************/
+
+/*
+ * si470x_get_report - receive a HID report
+ */
+static int si470x_get_report(struct si470x_device *radio, int size)
+{
+	return usb_control_msg(radio->usbdev,
+		usb_rcvctrlpipe(radio->usbdev, 0),
+		HID_REQ_GET_REPORT,
+		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+		radio->buf[0], 2,
+		radio->buf, size, usb_timeout);
+}
+
+
+/*
+ * si470x_set_report - send a HID report
+ */
+static int si470x_set_report(struct si470x_device *radio, int size)
+{
+	return usb_control_msg(radio->usbdev,
+		usb_sndctrlpipe(radio->usbdev, 0),
+		HID_REQ_SET_REPORT,
+		USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
+		radio->buf[0], 2,
+		radio->buf, size, usb_timeout);
+}
+
+
+/*
+ * si470x_get_register - read register
+ */
+static int si470x_get_register(struct si470x_device *radio, int regnr)
+{
+	int retval;
+
+	radio->buf[0] = REGISTER_REPORT(regnr);
+
+	retval = si470x_get_report(radio, REGISTER_REPORT_SIZE);
+	if (retval >= 0)
+		radio->registers[regnr] = (radio->buf[1] << 8) | radio->buf[2];
+
+	return (retval < 0) ? -EINVAL : 0;
+}
+
+
+/*
+ * si470x_set_register - write register
+ */
+static int si470x_set_register(struct si470x_device *radio, int regnr)
+{
+	int retval;
+
+	radio->buf[0] = REGISTER_REPORT(regnr);
+	radio->buf[1] = (radio->registers[regnr] & 0xff00) >> 8;
+	radio->buf[2] = (radio->registers[regnr] & 0x00ff);
+
+	retval = si470x_set_report(radio, REGISTER_REPORT_SIZE);
+
+	return (retval < 0) ? -EINVAL : 0;
+}
+
+
+/*
+ * si470x_get_all_registers - read entire registers
+ */
+static int si470x_get_all_registers(struct si470x_device *radio)
+{
+	int retval;
+	int regnr;
+
+	radio->buf[0] = ENTIRE_REPORT;
+
+	retval = si470x_get_report(radio, ENTIRE_REPORT_SIZE);
+
+	if (retval >= 0)
+		for (regnr = 0; regnr < FMRADIO_REGISTER_NUM; regnr++)
+			radio->registers[regnr] =
+			(radio->buf[regnr * FMRADIO_REGISTER_SIZE + 1] << 8) |
+			 radio->buf[regnr * FMRADIO_REGISTER_SIZE + 2];
+
+	return (retval < 0) ? -EINVAL : 0;
+}
+
+
+/*
+ * si470x_get_rds_registers - read rds registers
+ */
+static int si470x_get_rds_registers(struct si470x_device *radio)
+{
+	int retval;
+	int regnr;
+	int size;
+
+	radio->buf[0] = RDS_REPORT;
+
+	retval = usb_interrupt_msg(radio->usbdev,
+		usb_rcvctrlpipe(radio->usbdev, 1),
+		radio->buf, RDS_REPORT_SIZE, &size, usb_timeout);
+
+	if (retval >= 0) {
+		for (regnr = 0; regnr < RDS_REGISTER_NUM; regnr++) {
+			radio->registers[STATUSRSSI + regnr] =
+			(radio->buf[regnr * FMRADIO_REGISTER_SIZE + 1] << 8) |
+			 radio->buf[regnr * FMRADIO_REGISTER_SIZE + 2];
+		}
+	}
+
+	return (retval < 0) ? - EINVAL : 0;
+}
+
+
+/*
+ * si470x_start - switch on radio
+ */
+static int si470x_start(struct si470x_device *radio)
+{
+	int retval;
+
+	/* powercfg */
+	radio->registers[POWERCFG] =
+		POWERCFG_DMUTE | POWERCFG_ENABLE | POWERCFG_RDSM;
+	retval = si470x_set_register(radio, POWERCFG);
+	if (retval < 0)
+		return retval;
+
+	/* sysconfig 1 */
+	radio->registers[SYSCONFIG1] =
+		SYSCONFIG1_DE | SYSCONFIG1_RDS;
+	retval = si470x_set_register(radio, SYSCONFIG1);
+	if (retval < 0)
+		return retval;
+
+	/* sysconfig 2 */
+	radio->registers[SYSCONFIG2] =
+		(0x3f  << 8) |	/* SEEKTH */
+		(band  << 6) |	/* BAND */
+		(space << 4) |	/* SPACE */
+		15;		/* VOLUME (max) */
+	retval = si470x_set_register(radio, SYSCONFIG2);
+	if (retval < 0)
+		return retval;
+
+	/* reset last channel */
+	return si470x_set_chan(radio,
+		radio->registers[CHANNEL] & CHANNEL_CHAN);
+}
+
+
+/*
+ * si470x_stop - switch off radio
+ */
+static int si470x_stop(struct si470x_device *radio)
+{
+	/* powercfg */
+	radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
+	/* POWERCFG_ENABLE has to automatically go low */
+	radio->registers[POWERCFG] |= POWERCFG_ENABLE |	POWERCFG_DISABLE;
+	return si470x_set_register(radio, POWERCFG);
+}
+
+
+/*
+ * si470x_set_chan - set the channel
+ */
+static int si470x_set_chan(struct si470x_device *radio, int chan)
+{
+	int retval, i;
+
+	/* start tuning */
+	radio->registers[CHANNEL] &= ~CHANNEL_CHAN;
+	radio->registers[CHANNEL] |= CHANNEL_TUNE | chan;
+	retval = si470x_set_register(radio, CHANNEL);
+	if (retval < 0)
+		return retval;
+
+	/* wait till seek operation has completed */
+	i = 0;
+	do {
+		retval = si470x_get_register(radio, STATUSRSSI);
+		if (retval < 0)
+			return retval;
+	} while ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) &&
+		(++i < seek_retries));
+	if (i >= seek_retries)
+		printk(KERN_WARNING DRIVER_NAME
+			": seek does not finish after %d tries\n", i);
+
+	/* stop tuning */
+	radio->registers[CHANNEL] &= ~CHANNEL_TUNE;
+	return si470x_set_register(radio, CHANNEL);
+}
+
+
+/*
+ * si470x_get_freq - get the frequency
+ */
+static int si470x_get_freq(struct si470x_device *radio)
+{
+	int spacing, band_bottom, chan, freq;
+	int retval;
+
+	/* Spacing (kHz) */
+	switch (space) {
+		/* 0: 200 kHz (USA, Australia) */
+		default: spacing = 0.200 * FREQ_MUL; break;
+		/* 1: 100 kHz (Europe, Japan) */
+		case 1 : spacing = 0.100 * FREQ_MUL; break;
+		/* 2:  50 kHz */
+		case 2 : spacing = 0.050 * FREQ_MUL; break;
+	};
+
+	/* Bottom of Band (MHz) */
+	switch (band) {
+		/* 0: 87.5 - 108 MHz (USA, Europe) */
+		default: band_bottom = 87.5 * FREQ_MUL; break;
+		/* 1: 76   - 108 MHz (Japan wide band) */
+		case 1 : band_bottom = 76   * FREQ_MUL; break;
+		/* 2: 76   -  90 MHz (Japan) */
+		case 2 : band_bottom = 76   * FREQ_MUL; break;
+	};
+
+	/* read channel */
+	retval = si470x_get_register(radio, READCHAN);
+	if (retval < 0)
+		return retval;
+	chan = radio->registers[READCHAN] & READCHAN_READCHAN;
+
+	/* Frequency (MHz) = Spacing (kHz) x Channel + Bottom of Band (MHz) */
+	freq = chan * spacing + band_bottom;
+
+	return freq;
+}
+
+
+/*
+ * si470x_set_freq - set the frequency
+ */
+static int si470x_set_freq(struct si470x_device *radio, int freq)
+{
+	int spacing, band_bottom, chan;
+
+	/* Spacing (kHz) */
+	switch (space) {
+		/* 0: 200 kHz (USA, Australia) */
+		default: spacing = 0.200 * FREQ_MUL; break;
+		/* 1: 100 kHz (Europe, Japan) */
+		case 1 : spacing = 0.100 * FREQ_MUL; break;
+		/* 2:  50 kHz */
+		case 2 : spacing = 0.050 * FREQ_MUL; break;
+	};
+
+	/* Bottom of Band (MHz) */
+	switch (band) {
+		/* 0: 87.5 - 108 MHz (USA, Europe) */
+		default: band_bottom = 87.5 * FREQ_MUL; break;
+		/* 1: 76   - 108 MHz (Japan wide band) */
+		case 1 : band_bottom = 76   * FREQ_MUL; break;
+		/* 2: 76   -  90 MHz (Japan) */
+		case 2 : band_bottom = 76   * FREQ_MUL; break;
+	};
+
+	/* Chan = [ Freq (Mhz) - Bottom of Band (MHz) ] / Spacing (kHz) */
+	chan = (freq - band_bottom) / spacing;
+
+	return si470x_set_chan(radio, chan);
+}
+
+
+
+/*
+ * si470x_rds - rds processing function
+ */
+static void si470x_rds(struct si470x_device *radio)
+{
+	unsigned long flags;
+	unsigned char tmpbuf[3];
+	unsigned char blocknum;
+	unsigned char bler; /* RDS block errors */
+	unsigned short rds;
+	unsigned int i;
+
+	if (radio->users == 0)
+		return;
+	if (si470x_get_rds_registers(radio) < 0)
+		return;
+	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0) {
+		/* No RDS group ready */
+		return;
+	}
+	if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSS) == 0) {
+		/* RDS decoder not synchronized */
+		return;
+	}
+
+	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 */
+		tmpbuf[0] = rds & 0x00ff;	/* LSB */
+		tmpbuf[1] = (rds & 0xff00) >> 8;/* MSB */
+		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) */
+
+		spin_lock_irqsave(&radio->lock, flags);
+
+		/* copy RDS block to internal buffer */
+		for (i = 0; i < 3; i++) {
+			radio->buffer[radio->wr_index] = tmpbuf[i];
+			radio->wr_index++;
+		}
+
+		if (radio->wr_index >= radio->buf_size)
+			radio->wr_index = 0;
+
+		if (radio->wr_index == radio->rd_index) {
+			radio->rd_index += 3;
+			if (radio->rd_index >= radio->buf_size)
+				radio->rd_index = 0;
+		} else
+			radio->block_count++;
+
+		spin_unlock_irqrestore(&radio->lock, flags);
+	}
+
+	radio->data_available_for_read = 1;
+	wake_up_interruptible(&radio->read_queue);
+}
+
+
+/*
+ * si470x_timer - rds timer function
+ */
+static void si470x_timer(unsigned long data)
+{
+	struct si470x_device *radio = (struct si470x_device *) data;
+
+	schedule_work(&radio->work);
+}
+
+
+/*
+ * si470x_timer - rds work function
+ */
+static void si470x_work(struct work_struct *work)
+{
+	struct si470x_device *radio = container_of(work, struct si470x_device,
+		work);
+
+	if (radio->users == 0)
+		return;
+
+	si470x_rds(radio);
+	mod_timer(&radio->timer, jiffies + msecs_to_jiffies(rds_poll_time));
+}
+
+
+
+/**************************************************************************
+ * USB interface functions
+ **************************************************************************/
+
+/*
+ * 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;
+
+	if (!(radio = kmalloc(sizeof(struct si470x_device), GFP_KERNEL)))
+		return -ENOMEM;
+	if (!(radio->videodev = video_device_alloc())) {
+		kfree(radio);
+		return -ENOMEM;
+	}
+	memcpy(radio->videodev, &si470x_viddev_template,
+			sizeof(si470x_viddev_template));
+	radio->users = 0;
+	radio->usbdev = interface_to_usbdev(intf);
+	video_set_drvdata(radio->videodev, radio);
+	if (video_register_device(radio->videodev, VFL_TYPE_RADIO, radio_nr)) {
+		printk(KERN_WARNING DRIVER_NAME
+				": Could not register video device\n");
+		video_device_release(radio->videodev);
+		kfree(radio);
+		return -EIO;
+	}
+	usb_set_intfdata(intf, radio);
+
+	/* show some infos about the specific device */
+	if (si470x_get_all_registers(radio) < 0) {
+		video_device_release(radio->videodev);
+		kfree(radio);
+		return -EIO;
+	}
+	printk(KERN_INFO DRIVER_NAME ": DeviceID=0x%4.4x ChipID=0x%4.4x\n",
+			radio->registers[DEVICEID], radio->registers[CHIPID]);
+
+	/* check if firmware is current */
+	if ((radio->registers[CHIPID] & CHIPID_FIRMWARE)
+			< FMRADIO_SW_VERSION_CURRENT) {
+		printk(KERN_WARNING DRIVER_NAME
+			": This driver is known to work with chip version %d, "
+			"but the device has firmware %d. If you have some "
+			"trouble using this driver, please report to V4L ML "
+			"at video4linux-list@redhat.com\n",
+			radio->registers[CHIPID] & CHIPID_FIRMWARE,
+			FMRADIO_SW_VERSION_CURRENT);
+	}
+
+	/* set initial frequency */
+	si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
+
+	/* rds initialization */
+	radio->buf_size = rds_buf * 3;
+	if (NULL == (radio->buffer = kmalloc(radio->buf_size, GFP_KERNEL))) {
+		video_device_release(radio->videodev);
+		kfree(radio);
+		return -ENOMEM;
+	}
+	radio->block_count = 0;
+	radio->wr_index = 0;
+	radio->rd_index = 0;
+	radio->last_blocknum = 0xff;
+	init_waitqueue_head(&radio->read_queue);
+	radio->data_available_for_read = 0;
+
+	/* prepare polling via eventd */
+	INIT_WORK(&radio->work, si470x_work);
+	init_timer(&radio->timer);
+	radio->timer.function = si470x_timer;
+	radio->timer.data = (unsigned long) radio;
+
+	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);
+
+	del_timer_sync(&radio->timer);
+	flush_scheduled_work();
+
+	usb_set_intfdata(intf, NULL);
+	if (radio) {
+		video_unregister_device(radio->videodev);
+		kfree(radio->buffer);
+		kfree(radio);
+	}
+}
+
+
+
+/**************************************************************************
+ * Video4Linux interface functions
+ **************************************************************************/
+
+/*
+ * si470x_fops_read - read RDS data
+ */
+static ssize_t si470x_fops_read(struct file *file, char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+	struct rds_command cmd;
+	unsigned long flags;
+	unsigned int i;
+	unsigned int rd_blocks;
+
+	cmd.block_count = count / 3; /* each RDS block needs 3 bytes */
+	cmd.result = 0;
+	cmd.buffer = buf;
+	cmd.instance = file;
+
+	/* copy RDS block out of internal buffer */
+	while (!radio->data_available_for_read) {
+		if (wait_event_interruptible(radio->read_queue,
+				     radio->data_available_for_read) < 0)
+			return -EINTR;
+	}
+
+	spin_lock_irqsave(&radio->lock, flags);
+	rd_blocks = cmd.block_count;
+	if (rd_blocks > radio->block_count)
+		rd_blocks = radio->block_count;
+
+	if (!rd_blocks) {
+		spin_unlock_irqrestore(&radio->lock, flags);
+		return cmd.result;
+	}
+
+	for (i = 0; i < rd_blocks; i++) {
+		/* copy RDS block to user buffer */
+		if (radio->rd_index == radio->wr_index)
+			break;
+
+		if (copy_to_user(buf, &radio->buffer[radio->rd_index], 3))
+			break;
+
+		radio->rd_index += 3;
+		if (radio->rd_index >= radio->buf_size)
+			radio->rd_index = 0;
+		radio->block_count--;
+
+		buf += 3;
+		cmd.result += 3;
+	}
+	radio->data_available_for_read = (radio->block_count > 0);
+	spin_unlock_irqrestore(&radio->lock, flags);
+
+	return cmd.result;
+}
+
+
+/*
+ * si470x_fops_poll - poll RDS data
+ */
+static unsigned int si470x_fops_poll(struct file *file,
+		struct poll_table_struct *pts)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+	int retval;
+
+	retval = 0;
+	if (radio->data_available_for_read)
+		retval = POLLIN | POLLRDNORM;
+	poll_wait(file, &radio->read_queue, pts);
+
+	return retval;
+}
+
+
+/*
+ * si470x_fops_open - file open
+ */
+static int si470x_fops_open(struct inode *inode, struct file *file)
+{
+	int retval;
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	radio->users++;
+	if (radio->users == 1) {
+		retval = si470x_start(radio);
+		if (retval < 0)
+			return retval;
+
+		schedule_work(&radio->work);
+	}
+
+	return 0;
+}
+
+
+/*
+ * si470x_fops_release - file release
+ */
+static int si470x_fops_release(struct inode *inode, struct file *file)
+{
+	int retval;
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	if (!radio)
+		return -ENODEV;
+
+	radio->users--;
+	if (radio->users == 0) {
+		radio->data_available_for_read = 1;		/* ? */
+		wake_up_interruptible(&radio->read_queue);	/* ? */
+
+		retval = si470x_stop(radio);
+		if (retval < 0)
+			return retval;
+	}
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_querycap - query device capabilities
+ */
+static int si470x_vidioc_querycap(struct file *file, void *priv,
+		struct v4l2_capability *capability)
+{
+	strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
+	strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card));
+	sprintf(capability->bus_info, "USB");
+	capability->version = DRIVER_VERSION;
+	capability->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_g_input - get input
+ */
+static int si470x_vidioc_g_input(struct file *filp, void *priv,
+		unsigned int *i)
+{
+	*i = 0;
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_s_input - set input
+ */
+static int si470x_vidioc_s_input(struct file *filp, void *priv, unsigned int i)
+{
+	if (i != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_queryctrl - enumerate control items
+ */
+static int si470x_vidioc_queryctrl(struct file *file, void *priv,
+		struct v4l2_queryctrl *qc)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(radio_queryctrl); i++) {
+		if (qc->id && qc->id == radio_queryctrl[i].id) {
+			memcpy(qc, &(radio_queryctrl[i]), sizeof(*qc));
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+
+/*
+ * si470x_vidioc_g_ctrl - get the value of a control
+ */
+static int si470x_vidioc_g_ctrl(struct file *file, void *priv,
+		struct v4l2_control *ctrl)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	switch (ctrl->id) {
+		case V4L2_CID_AUDIO_VOLUME:
+			ctrl->value = radio->registers[SYSCONFIG2] &
+					SYSCONFIG2_VOLUME;
+			break;
+		case V4L2_CID_AUDIO_MUTE:
+			ctrl->value = ((radio->registers[POWERCFG] &
+					POWERCFG_DMUTE) == 0) ? 1 : 0;
+			break;
+	}
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_s_ctrl - set the value of a control
+ */
+static int si470x_vidioc_s_ctrl(struct file *file, void *priv,
+		struct v4l2_control *ctrl)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	switch (ctrl->id) {
+		case V4L2_CID_AUDIO_VOLUME:
+			radio->registers[SYSCONFIG2] &= ~SYSCONFIG2_VOLUME;
+			radio->registers[SYSCONFIG2] |= ctrl->value;
+			return si470x_set_register(radio, SYSCONFIG2);
+		case V4L2_CID_AUDIO_MUTE:
+			if (ctrl->value == 1)
+				radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
+			else
+				radio->registers[POWERCFG] |= POWERCFG_DMUTE;
+			return si470x_set_register(radio, POWERCFG);
+	}
+
+	return -EINVAL;
+}
+
+
+/*
+ * si470x_vidioc_g_audio - get audio attributes
+ */
+static int si470x_vidioc_g_audio(struct file *file, void *priv,
+		struct v4l2_audio *audio)
+{
+	if (audio->index > 1)
+		return -EINVAL;
+
+	strcpy(audio->name, "Radio");
+	audio->capability = V4L2_AUDCAP_STEREO;
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_s_audio - set audio attributes
+ */
+static int si470x_vidioc_s_audio(struct file *file, void *priv,
+		struct v4l2_audio *audio)
+{
+	if (audio->index != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_g_tuner - get tuner attributes
+ */
+static int si470x_vidioc_g_tuner(struct file *file, void *priv,
+		struct v4l2_tuner *tuner)
+{
+	int retval;
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	if (tuner->index > 0)
+		return -EINVAL;
+
+	/* read status rssi */
+	retval = si470x_get_register(radio, STATUSRSSI);
+	if (retval < 0)
+		return retval;
+
+	strcpy(tuner->name, "FM");
+	tuner->type = V4L2_TUNER_RADIO;
+	switch(band) {
+		/* 0: 87.5 - 108 MHz (USA, Europe, default) */
+		default:
+			tuner->rangelow  =  87.5 * FREQ_MUL;
+			tuner->rangehigh = 108   * FREQ_MUL;
+			break;
+		/* 1: 76   - 108 MHz (Japan wide band) */
+		case 1 :
+			tuner->rangelow  =  76   * FREQ_MUL;
+			tuner->rangehigh = 108   * FREQ_MUL;
+			break;
+		/* 2: 76   -  90 MHz (Japan) */
+		case 2 :
+			tuner->rangelow  =  76   * FREQ_MUL;
+			tuner->rangehigh =  90   * FREQ_MUL;
+			break;
+	};
+	tuner->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
+	tuner->capability = V4L2_TUNER_CAP_LOW;
+
+	/* Stereo indicator == Stereo (instead of Mono) */
+	if ((radio->registers[STATUSRSSI] & STATUSRSSI_ST) == 1)
+		tuner->audmode = V4L2_TUNER_MODE_STEREO;
+	else
+		tuner->audmode = V4L2_TUNER_MODE_MONO;
+
+	/* min is worst, max is best; signal:0..0xffff; rssi: 0..0xff */
+	tuner->signal = (radio->registers[STATUSRSSI] & STATUSRSSI_RSSI)
+				* 0x0101;
+
+	/* automatic frequency control: -1: freq to low, 1 freq to high */
+	tuner->afc = 0;
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_s_tuner - set tuner attributes
+ */
+static int si470x_vidioc_s_tuner(struct file *file, void *priv,
+		struct v4l2_tuner *tuner)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	if (tuner->index > 0)
+		return -EINVAL;
+
+	if (tuner->audmode == V4L2_TUNER_MODE_MONO)
+		radio->registers[POWERCFG] |= POWERCFG_MONO;  /* force mono */
+	else
+		radio->registers[POWERCFG] &= ~POWERCFG_MONO; /* try stereo */
+
+	return si470x_set_register(radio, POWERCFG);
+}
+
+
+/*
+ * si470x_vidioc_g_frequency - get tuner or modulator radio frequency
+ */
+static int si470x_vidioc_g_frequency(struct file *file, void *priv,
+		struct v4l2_frequency *freq)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	freq->type = V4L2_TUNER_RADIO;
+	freq->frequency = si470x_get_freq(radio);
+
+	return 0;
+}
+
+
+/*
+ * si470x_vidioc_s_frequency - set tuner or modulator radio frequency
+ */
+static int si470x_vidioc_s_frequency(struct file *file, void *priv,
+		struct v4l2_frequency *freq)
+{
+	struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+
+	if (freq->type != V4L2_TUNER_RADIO)
+		return -EINVAL;
+
+	return si470x_set_freq(radio, freq->frequency);
+}
+
+
+
+/**************************************************************************
+ * Module interface definitions and functions
+ **************************************************************************/
+
+/*
+ * si470x_module_init - module init
+ */
+static int __init si470x_module_init(void)
+{
+	printk(KERN_INFO DRIVER_DESC "\n");
+	return usb_register(&si470x_usb_driver);
+}
+
+
+/*
+ * si470x_module_exit - module exit
+ */
+static void __exit si470x_module_exit(void)
+{
+	usb_deregister(&si470x_usb_driver);
+}
+
+
+module_init(si470x_module_init);
+module_exit(si470x_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_VERSION("1.0.2");