Re: [PATCHv2 06/11] si4713: Added the USB driver for Si4713

[Mauro Carvalho Chehab <m.chehab@samsung.com>]

Em Fri,  6 Dec 2013 11:17:09 +0100
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> From: Dinesh Ram <Dinesh.Ram@cern.ch>
> 
> This is the USB driver for the Silicon Labs development board.
> It contains the Si4713 FM transmitter chip.
> 
> Signed-off-by: Dinesh Ram <dinesh.ram@cern.ch>
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> Tested-by: Eduardo Valentin <edubezval@gmail.com>
> Acked-by: Eduardo Valentin <edubezval@gmail.com>
> ---
>  drivers/media/radio/si4713/Kconfig            |  15 +
>  drivers/media/radio/si4713/Makefile           |   1 +
>  drivers/media/radio/si4713/radio-usb-si4713.c | 540 ++++++++++++++++++++++++++
>  3 files changed, 556 insertions(+)
>  create mode 100644 drivers/media/radio/si4713/radio-usb-si4713.c
> 
> diff --git a/drivers/media/radio/si4713/Kconfig b/drivers/media/radio/si4713/Kconfig
> index ec640b8..a7c3ba8 100644
> --- a/drivers/media/radio/si4713/Kconfig
> +++ b/drivers/media/radio/si4713/Kconfig
> @@ -1,3 +1,18 @@
> +config USB_SI4713
> +	tristate "Silicon Labs Si4713 FM Radio Transmitter support with USB"
> +	depends on USB && RADIO_SI4713
> +	select SI4713
> +	---help---
> +	  This is a driver for USB devices with the Silicon Labs SI4713
> +	  chip. Currently these devices are known to work.
> +	  - 10c4:8244: Silicon Labs FM Transmitter USB device.
> +
> +	  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-usb-si4713.
> +
>  config PLATFORM_SI4713
>  	tristate "Silicon Labs Si4713 FM Radio Transmitter support with I2C"
>  	depends on I2C && RADIO_SI4713
> diff --git a/drivers/media/radio/si4713/Makefile b/drivers/media/radio/si4713/Makefile
> index a8c1194..ddaaf92 100644
> --- a/drivers/media/radio/si4713/Makefile
> +++ b/drivers/media/radio/si4713/Makefile
> @@ -3,4 +3,5 @@
>  #
>  
>  obj-$(CONFIG_I2C_SI4713) += si4713.o
> +obj-$(CONFIG_USB_SI4713) += radio-usb-si4713.o
>  obj-$(CONFIG_PLATFORM_SI4713) += radio-platform-si4713.o
> diff --git a/drivers/media/radio/si4713/radio-usb-si4713.c b/drivers/media/radio/si4713/radio-usb-si4713.c
> new file mode 100644
> index 0000000..d978844
> --- /dev/null
> +++ b/drivers/media/radio/si4713/radio-usb-si4713.c
> @@ -0,0 +1,540 @@
> +/*
> + * Copyright 2013 Cisco Systems, Inc. and/or its affiliates.
> + * All rights reserved.
> + *
> + * This program is free software; you may redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; version 2 of the License.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
> + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
> + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
> + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
> + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
> + * SOFTWARE.
> + */
> +
> +/* kernel includes */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/usb.h>
> +#include <linux/init.h>
> +#include <linux/slab.h>
> +#include <linux/input.h>
> +#include <linux/mutex.h>
> +#include <linux/i2c.h>
> +/* V4l includes */
> +#include <linux/videodev2.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-event.h>
> +#include <media/si4713.h>
> +
> +#include "si4713.h"
> +
> +/* driver and module definitions */
> +MODULE_AUTHOR("Dinesh Ram <dinesh.ram@cern.ch>");
> +MODULE_DESCRIPTION("Si4713 FM Transmitter USB driver");
> +MODULE_LICENSE("GPL v2");
> +
> +/* The Device announces itself as Cygnal Integrated Products, Inc. */
> +#define USB_SI4713_VENDOR		0x10c4
> +#define USB_SI4713_PRODUCT		0x8244
> +
> +#define BUFFER_LENGTH			64
> +#define USB_TIMEOUT			1000
> +#define USB_RESP_TIMEOUT		50000
> +
> +/* USB Device ID List */
> +static struct usb_device_id usb_si4713_usb_device_table[] = {
> +	{USB_DEVICE_AND_INTERFACE_INFO(USB_SI4713_VENDOR, USB_SI4713_PRODUCT,
> +							USB_CLASS_HID, 0, 0) },
> +	{ }						/* Terminating entry */
> +};
> +
> +MODULE_DEVICE_TABLE(usb, usb_si4713_usb_device_table);
> +
> +struct si4713_usb_device {
> +	struct usb_device	*usbdev;
> +	struct usb_interface	*intf;
> +	struct video_device	vdev;
> +	struct v4l2_device	v4l2_dev;
> +	struct v4l2_subdev	*v4l2_subdev;
> +	struct mutex		lock;
> +	struct i2c_adapter	i2c_adapter;
> +
> +	u8			*buffer;
> +};
> +
> +static inline struct si4713_usb_device *to_si4713_dev(struct v4l2_device *v4l2_dev)
> +{
> +	return container_of(v4l2_dev, struct si4713_usb_device, v4l2_dev);
> +}
> +
> +static int vidioc_querycap(struct file *file, void *priv,
> +					struct v4l2_capability *v)
> +{
> +	struct si4713_usb_device *radio = video_drvdata(file);
> +
> +	strlcpy(v->driver, "radio-usb-si4713", sizeof(v->driver));
> +	strlcpy(v->card, "Si4713 FM Transmitter", sizeof(v->card));
> +	usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
> +	v->device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
> +	v->capabilities = v->device_caps | V4L2_CAP_DEVICE_CAPS;
> +
> +	return 0;
> +}
> +
> +static int vidioc_g_modulator(struct file *file, void *priv,
> +				struct v4l2_modulator *vm)
> +{
> +	struct si4713_usb_device *radio = video_drvdata(file);
> +
> +	return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_modulator, vm);
> +}
> +
> +static int vidioc_s_modulator(struct file *file, void *priv,
> +				const struct v4l2_modulator *vm)
> +{
> +	struct si4713_usb_device *radio = video_drvdata(file);
> +
> +	return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_modulator, vm);
> +}
> +
> +static int vidioc_s_frequency(struct file *file, void *priv,
> +				const struct v4l2_frequency *vf)
> +{
> +	struct si4713_usb_device *radio = video_drvdata(file);
> +
> +	return v4l2_subdev_call(radio->v4l2_subdev, tuner, s_frequency, vf);
> +}
> +
> +static int vidioc_g_frequency(struct file *file, void *priv,
> +				struct v4l2_frequency *vf)
> +{
> +	struct si4713_usb_device *radio = video_drvdata(file);
> +
> +	return v4l2_subdev_call(radio->v4l2_subdev, tuner, g_frequency, vf);
> +}
> +
> +static const struct v4l2_ioctl_ops usb_si4713_ioctl_ops = {
> +	.vidioc_querycap	  = vidioc_querycap,
> +	.vidioc_g_modulator	  = vidioc_g_modulator,
> +	.vidioc_s_modulator	  = vidioc_s_modulator,
> +	.vidioc_g_frequency	  = vidioc_g_frequency,
> +	.vidioc_s_frequency	  = vidioc_s_frequency,
> +	.vidioc_log_status	  = v4l2_ctrl_log_status,
> +	.vidioc_subscribe_event   = v4l2_ctrl_subscribe_event,
> +	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
> +};
> +
> +/* File system interface */
> +static const struct v4l2_file_operations usb_si4713_fops = {
> +	.owner		= THIS_MODULE,
> +	.open           = v4l2_fh_open,
> +	.release        = v4l2_fh_release,
> +	.poll           = v4l2_ctrl_poll,
> +	.unlocked_ioctl	= video_ioctl2,
> +};
> +
> +static void usb_si4713_video_device_release(struct v4l2_device *v4l2_dev)
> +{
> +	struct si4713_usb_device *radio = to_si4713_dev(v4l2_dev);
> +	struct i2c_adapter *adapter = &radio->i2c_adapter;
> +
> +	i2c_del_adapter(adapter);
> +	v4l2_device_unregister(&radio->v4l2_dev);
> +	kfree(radio->buffer);
> +	kfree(radio);
> +}
> +
> +/*
> + * This command sequence emulates the behaviour of the Windows driver.
> + * The structure of these commands was determined by sniffing the
> + * usb traffic of the device during startup.
> + * Most likely, these commands make some queries to the device.
> + * Commands are sent to enquire parameters like the bus mode,
> + * component revision, boot mode, the device serial number etc.
> + *
> + * These commands are necessary to be sent in this order during startup.
> + * The device fails to powerup if these commands are not sent.
> + *
> + * The complete list of startup commands is given in the start_seq table below.
> + */
> +static int si4713_send_startup_command(struct si4713_usb_device *radio)
> +{
> +	unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
> +	u8 *buffer = radio->buffer;
> +	int retval;
> +
> +	/* send the command */
> +	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
> +					0x09, 0x21, 0x033f, 0, radio->buffer,
> +					BUFFER_LENGTH, USB_TIMEOUT);
> +	if (retval < 0)
> +		return retval;
> +
> +	for (;;) {
> +		/* receive the response */
> +		retval = usb_control_msg(radio->usbdev, usb_rcvctrlpipe(radio->usbdev, 0),
> +				0x01, 0xa1, 0x033f, 0, radio->buffer,
> +				BUFFER_LENGTH, USB_TIMEOUT);
> +		if (retval < 0)
> +			return retval;
> +		if (!radio->buffer[1]) {
> +			/* USB traffic sniffing showed that some commands require
> +			 * additional checks. */
> +			switch (buffer[1]) {
> +			case 0x32:
> +				if (radio->buffer[2] == 0)
> +					return 0;
> +				break;
> +			case 0x14:
> +			case 0x12:
> +				if (radio->buffer[2] & SI4713_CTS)
> +					return 0;
> +				break;
> +			case 0x06:
> +				if ((radio->buffer[2] & SI4713_CTS) && radio->buffer[9] == 0x08)
> +					return 0;
> +				break;
> +			default:
> +				return 0;
> +			}
> +		}
> +		if (time_is_before_jiffies(until_jiffies))
> +			return -EIO;

According with include/linux/jiffies.h:

	time_is_before_jiffies(a) return true if a is before jiffies.

I suspect that you want to do just the opposite here: to return -EIO if
you passed the timeout given by until_jiffies.


> +		msleep(3);
> +	}
> +
> +	return retval;
> +}
> +
> +struct si4713_start_seq_table {
> +	int len;
> +	u8 payload[8];
> +};
> +
> +/*
> + * Some of the startup commands that could be recognized are :
> + * (0x03): Get serial number of the board (Response : CB000-00-00)
> + * (0x06, 0x03, 0x03, 0x08, 0x01, 0x0f) : Get Component revision
> + */
> +struct si4713_start_seq_table start_seq[] = {
> +
> +	{ 1, { 0x03 } },
> +	{ 2, { 0x32, 0x7f } },
> +	{ 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
> +	{ 2, { 0x14, 0x02 } },
> +	{ 2, { 0x09, 0x90 } },
> +	{ 3, { 0x08, 0x90, 0xfa } },
> +	{ 2, { 0x36, 0x01 } },
> +	{ 2, { 0x05, 0x03 } },
> +	{ 7, { 0x06, 0x00, 0x06, 0x0e, 0x01, 0x0f, 0x05 } },
> +	{ 1, { 0x12 } },
> +	/* Commands that are sent after pressing the 'Initialize'
> +		button in the windows application */
> +	{ 1, { 0x03 } },
> +	{ 1, { 0x01 } },
> +	{ 2, { 0x09, 0x90 } },
> +	{ 3, { 0x08, 0x90, 0xfa } },
> +	{ 1, { 0x34 } },
> +	{ 2, { 0x35, 0x01 } },
> +	{ 2, { 0x36, 0x01 } },
> +	{ 2, { 0x30, 0x09 } },
> +	{ 4, { 0x30, 0x06, 0x00, 0xe2 } },
> +	{ 3, { 0x31, 0x01, 0x30 } },
> +	{ 3, { 0x31, 0x04, 0x09 } },
> +	{ 2, { 0x05, 0x02 } },
> +	{ 6, { 0x06, 0x03, 0x03, 0x08, 0x01, 0x0f } },
> +};
> +
> +static int si4713_start_seq(struct si4713_usb_device *radio)
> +{
> +	int retval = 0;
> +	int i;
> +
> +	radio->buffer[0] = 0x3f;
> +
> +	for (i = 0; i < ARRAY_SIZE(start_seq); i++) {
> +		int len = start_seq[i].len;
> +		u8 *payload = start_seq[i].payload;
> +
> +		memcpy(radio->buffer + 1, payload, len);
> +		memset(radio->buffer + len + 1, 0, BUFFER_LENGTH - 1 - len);
> +		retval = si4713_send_startup_command(radio);
> +	}
> +
> +	return retval;
> +}
> +
> +static struct i2c_board_info si4713_board_info = {
> +	I2C_BOARD_INFO("si4713", SI4713_I2C_ADDR_BUSEN_HIGH),
> +};
> +
> +struct si4713_command_table {
> +	int command_id;
> +	u8 payload[8];
> +};
> +
> +/*
> + * Structure of a command :
> + *	Byte 1 : 0x3f (always)
> + *	Byte 2 : 0x06 (send a command)
> + *	Byte 3 : Unknown
> + *	Byte 4 : Number of arguments + 1 (for the command byte)
> + *	Byte 5 : Number of response bytes
> + */
> +struct si4713_command_table command_table[] = {
> +
> +	{ SI4713_CMD_POWER_UP,		{ 0x00, SI4713_PWUP_NARGS + 1, SI4713_PWUP_NRESP} },
> +	{ SI4713_CMD_GET_REV,		{ 0x03, 0x01, SI4713_GETREV_NRESP } },
> +	{ SI4713_CMD_POWER_DOWN,	{ 0x00, 0x01, SI4713_PWDN_NRESP} },
> +	{ SI4713_CMD_SET_PROPERTY,	{ 0x00, SI4713_SET_PROP_NARGS + 1, SI4713_SET_PROP_NRESP } },
> +	{ SI4713_CMD_GET_PROPERTY,	{ 0x00, SI4713_GET_PROP_NARGS + 1, SI4713_GET_PROP_NRESP } },
> +	{ SI4713_CMD_TX_TUNE_FREQ,	{ 0x03, SI4713_TXFREQ_NARGS + 1, SI4713_TXFREQ_NRESP } },
> +	{ SI4713_CMD_TX_TUNE_POWER,	{ 0x03, SI4713_TXPWR_NARGS + 1, SI4713_TXPWR_NRESP } },
> +	{ SI4713_CMD_TX_TUNE_MEASURE,	{ 0x03, SI4713_TXMEA_NARGS + 1, SI4713_TXMEA_NRESP } },
> +	{ SI4713_CMD_TX_TUNE_STATUS,	{ 0x00, SI4713_TXSTATUS_NARGS + 1, SI4713_TXSTATUS_NRESP } },
> +	{ SI4713_CMD_TX_ASQ_STATUS,	{ 0x03, SI4713_ASQSTATUS_NARGS + 1, SI4713_ASQSTATUS_NRESP } },
> +	{ SI4713_CMD_GET_INT_STATUS,	{ 0x03, 0x01, SI4713_GET_STATUS_NRESP } },
> +	{ SI4713_CMD_TX_RDS_BUFF,	{ 0x03, SI4713_RDSBUFF_NARGS + 1, SI4713_RDSBUFF_NRESP } },
> +	{ SI4713_CMD_TX_RDS_PS,		{ 0x00, SI4713_RDSPS_NARGS + 1, SI4713_RDSPS_NRESP } },
> +};
> +
> +static int send_command(struct si4713_usb_device *radio, u8 *payload, char *data, int len)
> +{
> +	int retval;
> +
> +	radio->buffer[0] = 0x3f;
> +	radio->buffer[1] = 0x06;
> +
> +	memcpy(radio->buffer + 2, payload, 3);
> +	memcpy(radio->buffer + 5, data, len);
> +	memset(radio->buffer + 5 + len, 0, BUFFER_LENGTH - 5 - len);
> +
> +	/* send the command */
> +	retval = usb_control_msg(radio->usbdev, usb_sndctrlpipe(radio->usbdev, 0),
> +					0x09, 0x21, 0x033f, 0, radio->buffer,
> +					BUFFER_LENGTH, USB_TIMEOUT);
> +
> +	return retval < 0 ? retval : 0;
> +}
> +
> +static int si4713_i2c_read(struct si4713_usb_device *radio, char *data, int len)
> +{
> +	unsigned long until_jiffies = jiffies + usecs_to_jiffies(USB_RESP_TIMEOUT) + 1;
> +	int retval;
> +
> +	/* receive the response */
> +	for (;;) {
> +		retval = usb_control_msg(radio->usbdev,
> +					usb_rcvctrlpipe(radio->usbdev, 0),
> +					0x01, 0xa1, 0x033f, 0, radio->buffer,
> +					BUFFER_LENGTH, USB_TIMEOUT);
> +		if (retval < 0)
> +			return retval;
> +
> +		/*
> +		 * Check that we get a valid reply back (buffer[1] == 0) and
> +		 * that CTS is set before returning, otherwise we wait and try
> +		 * again. The i2c driver also does the CTS check, but the timeouts
> +		 * used there are much too small for this USB driver, so we wait
> +		 * for it here.
> +		 */
> +		if (radio->buffer[1] == 0 && (radio->buffer[2] & SI4713_CTS)) {
> +			memcpy(data, radio->buffer + 2, len);
> +			return 0;
> +		}
> +		if (time_is_before_jiffies(until_jiffies)) {
> +			/* Zero the status value, ensuring CTS isn't set */
> +			data[0] = 0;
> +			return 0;
> +		}

Again, I think that the timeout condition is wrong here.

> +		msleep(3);
> +	}
> +}
> +
> +static int si4713_i2c_write(struct si4713_usb_device *radio, char *data, int len)
> +{
> +	int retval = -EINVAL;
> +	int i;
> +
> +	if (len > BUFFER_LENGTH - 5)
> +		return -EINVAL;
> +
> +	for (i = 0; i < ARRAY_SIZE(command_table); i++) {
> +		if (data[0] == command_table[i].command_id)
> +			retval = send_command(radio, command_table[i].payload,
> +						data, len);
> +	}
> +
> +	return retval < 0 ? retval : 0;
> +}
> +
> +static int si4713_transfer(struct i2c_adapter *i2c_adapter,
> +				struct i2c_msg *msgs, int num)
> +{
> +	struct si4713_usb_device *radio = i2c_get_adapdata(i2c_adapter);
> +	int retval = -EINVAL;
> +	int i;
> +
> +	if (num <= 0)
> +		return 0;
> +
> +	for (i = 0; i < num; i++) {
> +		if (msgs[i].flags & I2C_M_RD)
> +			retval = si4713_i2c_read(radio, msgs[i].buf, msgs[i].len);
> +		else
> +			retval = si4713_i2c_write(radio, msgs[i].buf, msgs[i].len);
> +		if (retval)
> +			break;
> +	}
> +
> +	return retval ? retval : num;
> +}
> +
> +static u32 si4713_functionality(struct i2c_adapter *adapter)
> +{
> +	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> +}
> +
> +static struct i2c_algorithm si4713_algo = {
> +	.master_xfer   = si4713_transfer,
> +	.functionality = si4713_functionality,
> +};
> +
> +/* This name value shows up in the sysfs filename associated
> +		with this I2C adapter */
> +static struct i2c_adapter si4713_i2c_adapter_template = {
> +	.name   = "si4713-i2c",
> +	.owner  = THIS_MODULE,
> +	.algo   = &si4713_algo,
> +};
> +
> +int si4713_register_i2c_adapter(struct si4713_usb_device *radio)
> +{
> +	radio->i2c_adapter = si4713_i2c_adapter_template;
> +	/* set up sysfs linkage to our parent device */
> +	radio->i2c_adapter.dev.parent = &radio->usbdev->dev;
> +	i2c_set_adapdata(&radio->i2c_adapter, radio);
> +
> +	return i2c_add_adapter(&radio->i2c_adapter);
> +}
> +
> +/* check if the device is present and register with v4l and usb if it is */
> +static int usb_si4713_probe(struct usb_interface *intf,
> +				const struct usb_device_id *id)
> +{
> +	struct si4713_usb_device *radio;
> +	struct i2c_adapter *adapter;
> +	struct v4l2_subdev *sd;
> +	int retval = -ENOMEM;
> +
> +	dev_info(&intf->dev, "Si4713 development board discovered: (%04X:%04X)\n",
> +			id->idVendor, id->idProduct);
> +
> +	/* Initialize local device structure */
> +	radio = kzalloc(sizeof(struct si4713_usb_device), GFP_KERNEL);
> +	if (radio)
> +		radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
> +
> +	if (!radio || !radio->buffer) {
> +		dev_err(&intf->dev, "kmalloc for si4713_usb_device failed\n");
> +		kfree(radio);
> +		return -ENOMEM;
> +	}
> +
> +	mutex_init(&radio->lock);
> +
> +	radio->usbdev = interface_to_usbdev(intf);
> +	radio->intf = intf;
> +	usb_set_intfdata(intf, &radio->v4l2_dev);
> +
> +	retval = si4713_start_seq(radio);
> +	if (retval < 0)
> +		goto err_v4l2;
> +
> +	retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
> +	if (retval < 0) {
> +		dev_err(&intf->dev, "couldn't register v4l2_device\n");
> +		goto err_v4l2;
> +	}
> +
> +	retval = si4713_register_i2c_adapter(radio);
> +	if (retval < 0) {
> +		dev_err(&intf->dev, "could not register i2c device\n");
> +		goto err_i2cdev;
> +	}
> +
> +	adapter = &radio->i2c_adapter;
> +	sd = v4l2_i2c_new_subdev_board(&radio->v4l2_dev, adapter,
> +					  &si4713_board_info, NULL);
> +	radio->v4l2_subdev = sd;
> +	if (!sd) {
> +		dev_err(&intf->dev, "cannot get v4l2 subdevice\n");
> +		retval = -ENODEV;
> +		goto del_adapter;
> +	}
> +
> +	radio->vdev.ctrl_handler = sd->ctrl_handler;
> +	radio->v4l2_dev.release = usb_si4713_video_device_release;
> +	strlcpy(radio->vdev.name, radio->v4l2_dev.name,
> +		sizeof(radio->vdev.name));
> +	radio->vdev.v4l2_dev = &radio->v4l2_dev;
> +	radio->vdev.fops = &usb_si4713_fops;
> +	radio->vdev.ioctl_ops = &usb_si4713_ioctl_ops;
> +	radio->vdev.lock = &radio->lock;
> +	radio->vdev.release = video_device_release_empty;
> +	radio->vdev.vfl_dir = VFL_DIR_TX;
> +
> +	video_set_drvdata(&radio->vdev, radio);
> +	set_bit(V4L2_FL_USE_FH_PRIO, &radio->vdev.flags);
> +
> +	retval = video_register_device(&radio->vdev, VFL_TYPE_RADIO, -1);
> +	if (retval < 0) {
> +		dev_err(&intf->dev, "could not register video device\n");
> +		goto del_adapter;
> +	}
> +
> +	dev_info(&intf->dev, "V4L2 device registered as %s\n",
> +			video_device_node_name(&radio->vdev));
> +
> +	return 0;
> +
> +del_adapter:
> +	i2c_del_adapter(adapter);
> +err_i2cdev:
> +	v4l2_device_unregister(&radio->v4l2_dev);
> +err_v4l2:
> +	kfree(radio->buffer);
> +	kfree(radio);
> +	return retval;
> +}
> +
> +static void usb_si4713_disconnect(struct usb_interface *intf)
> +{
> +	struct si4713_usb_device *radio = to_si4713_dev(usb_get_intfdata(intf));
> +
> +	dev_info(&intf->dev, "Si4713 development board now disconnected\n");
> +
> +	mutex_lock(&radio->lock);
> +	usb_set_intfdata(intf, NULL);
> +	video_unregister_device(&radio->vdev);
> +	v4l2_device_disconnect(&radio->v4l2_dev);
> +	mutex_unlock(&radio->lock);
> +	v4l2_device_put(&radio->v4l2_dev);
> +}
> +
> +/* USB subsystem interface */
> +static struct usb_driver usb_si4713_driver = {
> +	.name			= "radio-usb-si4713",
> +	.probe			= usb_si4713_probe,
> +	.disconnect		= usb_si4713_disconnect,
> +	.id_table		= usb_si4713_usb_device_table,
> +};
> +
> +module_usb_driver(usb_si4713_driver);


-- 

Cheers,
Mauro